New South Wales Supreme Court CITATION : Wallace v Ramsay Health Care Ltd [2010] NSWSC 518 HEARING DATE(S) : 21 - 25 June 2010 JUDGMENT DATE : 9 July 2010 JUDGMENT OF : Harrison J DECISION : Verdict for the second defendant with costs. CATCHWORDS : NEGLIGENCE – medical negligence – spinal surgery – risks of surgery – failure to warn – where plaintiff suffered bilateral femoral neurapraxia following posterior lumbar interbody fusion – where no warning given of that risk despite general warning in standard terms – whether breach of duty to warn – whether plaintiff suffered harm in the circumstances - whether plaintiff would have declined surgery if warned of the risk of harm that materialised – whether harm caused by failure to warn – where plaintiff would not have declined surgery in any event - bilateral femoral neurapraxia not caused by defendant's breach of duty. LEGISLATION CITED : Civil Liability Act 2002 CATEGORY : Principal judgment Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; (2009) 239 CLR 420 Ambulance Service of NSW v Worley [2006] NSWCA 102 CASES CITED : Rogers v Whitaker [1992] HCA 58; (1992) 175 CLR 479 Rosenberg v Percival [2001] HCA 18; (2001) 205 CLR 434 Sidaway v Board of Governors of the Bethlem Royal Hospital [1985] AC 871 Ian Wallace (Plaintiff) PARTIES : Ramsay Health Care Limited t/as Westmead Private Hospital (First Defendant) Andrew Kam (Second Defendant) FILE NUMBER(S) : SC 2007/265252 COUNSEL : P W Bates with P G White (Plaintiff) M J Fordham (Second Defendant) SOLICITORS : Gerard Malouf & Partners (Plaintiff) TressCox Lawyers (Second Defendant) IN THE SUPREME COURT OF NEW SOUTH WALES COMMON LAW DIVISION HARRISON J 9 July 2010 2007/265252 Ian Wallace v Ramsay Health Care Limited t/as Westmead Private Hospital and Dr Andrew Kam JUDGMENT 1 HIS HONOUR: Dr Kam, the second defendant, is a neurosurgeon. On 22 November 2004 he performed a posterior lumbar interbody fusion on the plaintiff. The operation lasted over six hours. The plaintiff alleges that he is now an incomplete paraplegic and that this was caused by the negligence of the defendant. Despite the fact that earlier versions of the statement of claim alleged that the operation was performed negligently, and that it should not have been performed at all, these allegations have since been abandoned. The plaintiff's case is now entirely restricted to a complaint that Dr Kam failed properly to warn him that the procedure was attended by a number of risks associated with the possibility of adverse consequences. These are referred to in more detail below. 2 In the result, three general issues remain for determination. First, did Dr Kam breach his duty to the plaintiff by failing to give a proper warning of the risks of the surgery he performed? (The breach issue). Secondly, did the plaintiff suffer harm in the circumstances? (The injury issue). Thirdly, if he did, was that harm caused by Dr Kam's negligence? (The causation issue). 3 The parties are agreed that, in the event that the plaintiff becomes entitled to a verdict against Dr Kam, his damages are to be calculated at $350,000. There is also an agreement that Dr Kam will pay the plaintiff's costs in those circumstances. The proceedings against the first defendant have been discontinued. Background 4 The plaintiff was born in 1947 and is now almost 63 years of age. He is married with two adult children. His wife is in full time employment. He completed his secondary education in India. He came to Australia in 1980. He most recently followed employment as an insurance loss assessor and investigator. In the course of carrying heavy equipment in that role he developed a back condition, which led him to the surgery ultimately performed by Dr Kam in November 2004. 5 The plaintiff's back pain worsened at the end of 2003 and into 2004. He sought medical treatment. He was subjected to procedures including a lumbar block, a bone scan, epidural anaesthesia, an MRI and CT scans. He consulted various specialists including Dr Diwan at St George Private Hospital and Dr Charles New at Wahroonga, as well as Dr Kam. He was diagnosed with an intervertebral disc protrusion in his lumbar spine. 6 The plaintiff recalled that he saw Dr Kam two or three times in 2004. On the second occasion the pain was getting worse and he said that Dr Kam told him to lose weight. He said Dr Kam suggested he should reduce his weight to 100 kilograms. He said that by that stage he "was desperate for some relief as [he] could hardly walk". He went on a crash diet, stopped drinking alcohol and went from 124 kilograms to 110 kilograms over about three months. He said that, contrary to what he had been told, the reduction in his weight did not produce a corresponding ease in the severity of his pain. 7 Dr Kam went overseas in September 2004. The plaintiff saw him again on 5 October 2004. He was then still in severe pain. Dr Kam recommended surgery immediately. The plaintiff said Dr Kam told him that if he did not have surgery he would end up in a wheelchair, become incontinent and lose control of his bowels. The plaintiff said that that "really scared the hell out of [him]". The plaintiff said that "because [he] was in so much pain", Dr Kam arranged for him to undergo surgery on 22 November 2004. 8 The plaintiff said that he recalls waking up after the operation in extreme pain. Both his legs were paralysed. This was around 10.00pm. He said he was in agony and sedated with morphine. At 10.15pm he underwent what he described as an emergency MRI. He said that before that occurred Dr Kam had told him that, depending on the results, he would be operated on again either that night or first thing the following morning. The operation in fact took place the next morning. The plaintiff said that he remembered waking up in severe pain despite regular doses of morphine. He said that the pain was intolerable and his legs were still paralysed. 9 The plaintiff said that after the operation he could not stand up or lean back. He said, "I basically couldn't do anything at all". He was put on a hard board tilted to about 45 degrees for 10 minutes at a time twice each day as part of his physiotherapeutic treatment. He remained at Westmead Private Hospital for about 10 days and was unable to move very much at all. He said that he could not even sit on a wheelchair. 10 The plaintiff was transferred to St Joseph's Hospital at Auburn on a stretcher bed where he remained from about 16 December 2004 until about 14 February 2005. He underwent intensive physiotherapy but could still not move and had to be lifted in and out of bed using a hoist. He said that the time at St Joseph's was the most demeaning time in his life. He was embarrassed and mortified. He could not move his legs and was in constant pain. 11 In his 8 August 2008 statement the plaintiff said that his physical condition had not improved and was actually becoming worse. He described his back pain as "absolute agony". The pain radiated down his legs. His thighs and legs were numb. His left leg stiffened and occasionally cramped when he tried to walk. He could not sit still for long "because after a while it feels like [he is] sitting on a pile of stones or rocks". He said that his muscles became so stiff that he was required constantly to change position. He said that he could not walk without the assistance of a walking frame. The plaintiff said that for approximately six months following the operation he was literally confined to bed and gradually forced himself to mobilise until he was finally able to use the walking frame. The statutory framework 12 A number of sections of the Civil Liability Act 2002 are relevant in varying degrees to the present inquiry. They are as follows: " 5B General principles (1) A person is not negligent in failing to take precautions against a risk of harm unless: (a) the risk was foreseeable (that is, it is a risk of which the person knew or ought to have known), and (b) the risk was not insignificant, and (c) in the circumstances, a reasonable person in the person's position would have taken those precautions. (2) In determining whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (amongst other relevant things): (a) the probability that the harm would occur if care were not taken, (b) the likely seriousness of the harm, (c) the burden of taking precautions to avoid the risk of harm, (d) the social utility of the activity that creates the risk of harm. 5C Other principles In proceedings relating to liability for negligence: (a) the burden of taking precautions to avoid a risk of harm includes the burden of taking precautions to avoid similar risks of harm for which the person may be responsible, and (b) the fact that a risk of harm could have been avoided by doing something in a different way does not of itself give rise to or affect liability for the way in which the thing was done, and (c) the subsequent taking of action that would (had the action been taken earlier) have avoided a risk of harm does not of itself give rise to or affect liability in respect of the risk and does not of itself constitute an admission of liability in connection with the risk. 5D General principles (1) A determination that negligence caused particular harm comprises the following elements: (a) that the negligence was a necessary condition of the occurrence of the harm ('factual causation'), and (b) that it is appropriate for the scope of the negligent person's liability to extend to the harm so caused ('scope of liability'). (2) In determining in an exceptional case, in accordance with established principles, whether negligence that cannot be established as a necessary condition of the occurrence of harm should be accepted as establishing factual causation, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party. (3) If it is relevant to the determination of factual causation to determine what the person who suffered harm would have done if the negligent person had not been negligent: (a) the matter is to be determined subjectively in the light of all relevant circumstances, subject to paragraph (b), and (b) any statement made by the person after suffering the harm about what he or she would have done is inadmissible except to the extent (if any) that the statement is against his or her interest. (4) For the purpose of determining the scope of liability, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party. 5H No proactive duty to warn of obvious risk (1) A person ('the defendant') does not owe a duty of care to another person ('the plaintiff') to warn of an obvious risk to the plaintiff. (2) This section does not apply if: (a) the plaintiff has requested advice or information about the risk from the defendant, or (b) the defendant is required by a written law to warn the plaintiff of the risk, or (c) the defendant is a professional and the risk is a risk of the death of or personal injury to the plaintiff from the provision of a professional service by the defendant. (3) Subsection (2) does not give rise to a presumption of a duty to warn of a risk in the circumstances referred to in that subsection. 5I No liability for materialisation of inherent risk (1) A person is not liable in negligence for harm suffered by another person as a result of the materialisation of an inherent risk. (2) An 'inherent risk' is a risk of something occurring that cannot be avoided by the exercise of reasonable care and skill. (3) This section does not operate to exclude liability in connection with a duty to warn of a risk. 5O Standard of care for professionals (1) A person practising a profession ( 'a professional') does not incur a liability in negligence arising from the provision of a professional service if it is established that the professional acted in a manner that (at the time the service was provided) was widely accepted in Australia by peer professional opinion as competent professional practice. (2) However, peer professional opinion cannot be relied on for the purposes of this section if the court considers that the opinion is irrational. (3) The fact that there are differing peer professional opinions widely accepted in Australia concerning a matter does not prevent any one or more (or all) of those opinions being relied on for the purposes of this section. (4) Peer professional opinion does not have to be universally accepted to be considered widely accepted. 5P Division does not apply to duty to warn of risk This Division does not apply to liability arising in connection with the giving of (or the failure to give) a warning, advice or other information in respect of the risk of death of or injury to a person associated with the provision by a professional of a professional service." 13 These provisions are referred to more fully in the reasons that follow. The breach issue 14 Resolution of this issue turns in the first instance upon a comparison of what Dr Kam actually told the plaintiff and what the law determines he should have been told. There is a dispute between the plaintiff and Dr Kam about each of these. The plaintiff's evidence 15 The plaintiff said that he remembered being told by Dr Kam, "after you have the surgery you will be out of hospital and home by Christmas and be back at work by January 2005". The plaintiff said that this gave him the confidence to go ahead with the surgery. He said that until then he had been reluctant to have the operation but then became confident that it was the right thing to do. 16 Paragraphs 15 and 16 of the plaintiff's statement dated 8 August 2008 were in these terms: "15. Dr Kam also told me that there was a seventy five percent chance of the operation being successful. Dr Kam did not mention anything that could go wrong and I was under the impression that if the surgery was unsuccessful, I would simply be the way I was before the surgery. He did mention that he had operated on two persons who had not improved following the operation. Dr Kam also informed me that after the surgery, I would be able to stop taking my medications and that I would be in no pain at all if it was successful. By this time my medications had more than quadrupled in quantity and strength from when I first started taking them. 16. At no stage did Dr Kam mention to me what could go wrong or what would happen to me if the surgery was unsuccessful. I believed that there were no negative aspects to the surgery and the worse [sic] that could happen was that I would simply be the way I was before the operation." 17 Much the same theme appears in paragraph 26 of that statement which was relevantly as follows: "26. … As a result of what Dr Kam told me, I believed that there was a 75% chance of the operation being successful and that if the operation was unsuccessful, I would have simply been the way I was before the operation. It was Dr Kam's statement that I would be home by Christmas and working the next year as well as Dr Kam's indication that Dr Diwan was involved that made me decide to have the operation. I should mention that Dr Diwan had the reputation of being a leader in the field of spinal surgery and that is why I was so keen to have him on board. I honestly believed that my personal condition could only improve and especially I would be weaned off the medication I was on." 18 In a supplementary statement dated 8 June 2010, the plaintiff relevantly had this to say on the issue of what he had been told by Dr Kam prior to the surgery: "5. … Dr Kam said that 'If you do not agree to surgery, you will most likely end up on a wheel chair, and you would most probably become incontinent, and you will be in even greater pain and on much more medication than you are now'. At no time did he make any mention of the possible adverse consequences of surgery on an overweight person. I have a clear and precise recollection of Dr Kam assuring me 'You will be home by Christmas and back at work by the first month of the New Year 2005. 6. I clearly recall asking Dr Kam 'What is the likely outcome of surgery?' He informed me that 'there was a 70% to 75% chance of success you would have considerably less pain; you would be taking much less medication; you would be able to walk'. He also clearly assured me that 'You would be home by Christmas and back at work by the end of January 2005'. I have a vague recollection that he also said that 'total recuperation would take about six months'. I also have a recollection of asking Dr Kam 'What would happen if the surgery was not successful?' and he told me that 'You would remain the same as you are'." 19 The plaintiff was cross-examined about his conversation with Dr Kam as follows: "Q. You are absolutely clear, aren't you, that as part of your conversation with Dr Kam in or about October 2004 that there was a discussion in which figures of 70 or 75 per cent in relation to the success of surgery were mentioned? A. Yes, those sort of figures were mentioned but I don't know when. It was during the consultation with Dr Kam, I don't know what dates. Q. There is no doubt about it, Dr Kam said that to you prior to your surgery? A. Yes. Q. You understood when those words were used that there was a 25 to 30 per cent chance that the surgery wouldn't be successful? A. Yes." 20 The plaintiff was cross-examined about what Dr Kam had said to him about weight loss. Part of that evidence is as follows: "Q. He told you that because of your then weight it was in your interests to attempt to lose weight before considering surgery? A. He said that I should get down to about 100 kilos before surgery could be considered. Q. Can I suggest to you that as at January 2004, and I will go through each visit with you, what he said to you was that it was in your interests to attempt a significant weight reduction before considering surgery. Do you agree with that? A. Yes. Q. In relation to weight loss doctor had a conversation with you about how you might lose some weight? A. He would have said things, yes. Q. I am going to put some specifics to you. He spoke to you about reducing the numbers of calories that you were taking in? A. He would have said, yes, he would have gone through the whole lot of examples, yes. Q. Sitting here today, do you remember doctor talking to you about the way you might try and lose weight? A. I can't remember specifics, but he definitely told me the different ways I could lose weight. Q. Specifically he told you about different types of foods and restricting things like carbohydrates, rice, junk food, sugary drinks, et cetera? A. He would have definitely told me that, yes. Q. He encouraged you to use skim milk when you were having tea and coffee? A. Possible. As I say, I can't remember specifics but if it is there on notes it's possible. Q. You can't say one way or the other; is that what you are saying? A. No, that's what I am trying to say, yes. Q. I will go through them all and ask certain questions. If you were to have soft drinks you should try to choose the diet, light or low sugar ones? A. Possible. Q. You needed to get some exercise to burn some calories? A. Very possible. Q. Sitting here today, do you remember doctor telling you firstly that you had to lose some weight? A. Yes. Q. And, secondly, that there were ways that you could do it? A. Yes. Q. And if I suggested to you that what doctor told you was all those matters the doctor put to you about all the types of food you could eat and drink and the use of exercise, you wouldn't disagree with him having said that to you, would you? A. No, definitely not, no. Q. You had lost some weight shortly to your meeting with him, didn't you? A. I thought I did according to my bathroom scales. I said that before. Q. And you told him that? A. Yes. Q. And after being told that he still said to you you needed to persevere and lose some more? A. Yes. Q. Before making a decision about surgery? A. Yes. Q. He also told you that if you had some weight loss there was a good chance your pain might improve? A. Yes. Q. And you might be able to avoid surgery? A. Yes. Q. Because the discussion about surgery as far as you were concerned was in some way in order to try and reduce the pain you were suffering; correct? A. Yes. Q. And it was suggested to you that if there was no improvement even after weight loss then you might have to have some surgery? A. Yes." 21 The plaintiff was asked some further questions about weight loss as follows: "Q. Even having lost that weight, you still had significant pain in your lower back and legs; correct? A. Yes. Q. And what doctor said to you was, well, you really need to continue to try and to lose weight, didn't he? A. Yes. Q. And it should be deferred, any surgery should be deferred at that point? A. Yes. Q. He told you that if you lost more weight there was a chance your pain might improve? A. Yes. Q. You might be able to avoid surgery? A. Yes. Q. He also suggested to you that you should try and get down to about 100 kilograms? A. Yes. Q. And on your reckoning you were down to somewhere between 105 and 110 at that point, weren't you? A. Yes. Q. He also suggested to you that even if you lost weight your pain may not improve and you may have to have surgery? A. Yes, possible." 22 The plaintiff was somewhat later cross-examined in these terms: "Q. Dr Kam specifically said to you that any surgery has risks and complications, didn't he? A. Oh, yes. Q. You had lipoma surgery that had gone very badly, hadn't you? A. Yes. Q. You knew surgery had risks and complications, didn't you? A. Absolutely. Q. You also knew that spinal surgery was a serious business; correct? A. Absolutely. Q. He said to you, 'There are no guarantees', didn't he? A. I can't remember him saying that to me, no. Q. You certainly remember a figure, and it is used differently and I am not criticising you for it, but either 70 or 75 per cent chance of success? A. That's correct. Q. You have already answered this question, but you understood there was a 25 to 30 per cent chance that the surgery wouldn't be successful? A. Yes. Q. Doctor specifically told you that there was a risk that you could have an injury to your nerve roots? A. I can't remember him saying that to me at all. Q. You were told that you could be left with weakness in either or both of your legs? A. Definitely not. Q. You were told you could have spinal cord injury? A. Definitely not. Q. Which could affect either or both of your legs? A. No. Q. You were told that as a result of the surgery you could develop bladder and bowel incontinence? A. No, emphatically no. Q. You were told, weren't you, there was a risk of bleeding? A. Definitely bleeding, sure. It's an operation. Q. Significant bleeding? A. I don't know about significant bleeding, but an operation does involve bleeding, sure. Q. You were told that that might require a blood transfusion? A. Yes. Q. You were told there was a risk that you might have an infection? A. Yes. Q. And you were also told that that risk, that being the risk of infection, was higher because of your diabetes and morbid obesity, your weight? A. I can't remember anything about obesity but definitely about diabetes, yes. Q. Certainly told there was a greater risk of infection; do you agree with that? A. In relation to what? Q. You were told there was a risk of infection? A. For diabetes, yes. Q. You were told there was a higher risk of infection than was usually the case because of, one, your diabetes? A. Yes. Q. And, two, your weight? A. No. Q. You were told there was a risk of failure of the hardware that was going to be put in? A. No. Q. You were told that screws and the like could loosen or fracture? A. I can't remember him saying that. Q. You were told that if the hardware failed in any way you would require further surgery? A. I think that's obvious. Q. You perfectly well knew there could be further surgery if things didn't go well? A. No. If things went wrong it is obvious that further surgery is indicated. Q. You were told the surgery may take longer than it otherwise might because of your weight and size? A. No. Q. You were also told that the length of time for your rehabilitation after the operation would take longer because of your size? A. No. Q. You were told if things went well you would be in hospital for seven to 10 days? A. Yes. Q. And that depending on how it went you would be discharged and may be able to go home after those seven to 10 days? A. That's correct. Q. You would then have to attend for rehabilitation? A. Yes. Q. For about two to four weeks? A. Yes. Q. And that if things went well you might be able to return to office based employment in 10 to 12 weeks? A. I don't know about 10 to 12 weeks, but it was in January of the following year. Q. This was October? A. It's possible. Q. And you were specifically told that rehabilitation could take longer because of your size? A. No. Q. You were told, weren't you, that even if the surgery goes well your back pain might not be resolved and it might continue? A. Definitely not. Q. You've agreed that you were told about the probability of a successful outcome being 70 per cent, don't you? A. Yes." 23 The cross-examination of the plaintiff concluded with the following passage of evidence: "Q. When bladder and bowel was discussed between you and the doctor as at October 2004, it was in the context of a risk of having surgery? A. I can't remember bladder and bowel. All I remember is he said that if I didn't have surgery I would be incontinent, that's all. Q. I want to suggest to you that the doctor did not say those words, do you agree or disagree? A. Dr Kam said those words, and I'm emphatic about that. Q. That's something you say you do remember amongst all the other matters we have discussed? A. Absolutely. Q. In discussing the risks of surgery and when dealing with the percentages that you have used in your evidence of either 70 or 75 and 30 or 25, it was in the context of the chances of the surgery being successful or unsuccessful, do you agree? A. To answer that question I have to say that Dr Kam told me that there was a 70 to 75 per cent chance of success. That's what I'm prepared to say. Q. You well understood that that meant that there was a 25 to 30 per cent chance that surgery would not be successful? A. I think that's quite obvious." Mrs Wallace's evidence 24 Mrs Wallace attended her husband's appointments with Dr Kam. She confirmed that from 2003 his back pain became worse and that it continued to do so right up until the day of the surgery. She also confirmed that the plaintiff's use of medications increased significantly between 2003 and October and November 2004. His mobility decreased over the same period. It was necessary for him to take most of his meals in his bedroom and a small refrigerator was installed there to facilitate that. 25 During September 2004 the plaintiff suffered increased levels of pain. He was unable to move because of the pain. The plaintiff's narcotic medication did not appear to work at all times. He became frustrated and upset because of the pain, his inability to move and the financial strain upon himself and the family as a result. He exhibited signs of depression. 26 Mrs Wallace was present with Dr Kam when the plaintiff described how much pain he was suffering. He said that his pain was really bad and that he had been unable to leave the house for four weeks. She said that he told Dr Kam that he had not really been able to get out of bed. She gave the following answers in cross-examination" "Q. And what was said were words to the effect of Dr Kam saying, 'Well, because of your pain and its increase and your inability to move around and your inability to get from your bedroom to your kitchen, we should consider proceeding with the surgery'? A. Yes. Q. He said in addition to that he would consider that, despite the fact that he hadn't lost enough weight yet; correct? A. I can't remember about that bit, but I know he talked about surgery. Q. I want to suggest to you that Dr Kam specifically said, 'Even though you haven't lost enough weight, we need to consider proceeding with the surgery'? A. Yes, I think he did, yes. Q. Or words to that effect? A. Yes. ***** Q. A discussion in that consultation then took place about the risks of the surgery itself, didn't it? A. Yes. Q. I am not saying this is verbatim, but doctor said words to the effect of any surgery is accompanied by risks and complications? A. Yes. Q. He said there are no guarantees? A. Yes. Q. He told your husband and you that there was a risk of nerve root injury? A. Yes. Q. And that your husband could be left with weakness in either or both of his legs after the surgery? A. I can't remember that bit. Q. He said there was a risk of injury to the spinal cord as a result of the surgery? A. I can't remember a lot of stuff, only the basic things I can remember. Q. Is it the case that sitting here today there are certain things you remember and other things you are not sure about? A. I can't give you a definite yes when I can't remember. Q. You certainly don't deny that any of these things were said, do you? A. Yeah, as a surgeon he would have said that to his patient." 27 Mrs Wallace otherwise generally confirmed the evidence given by her husband concerning what he was told by Dr Kam prior to the surgery. Dr Kam's evidence 28 Dr Kam is currently attached to the Department of Neurosurgery at Westmead Hospital at which he is the Director of Spinal Trauma. He made a statement dated 18 June 2010. Most of the matters to which he refers are uncontested. This includes the background material and history that the plaintiff provided in the course of three consultations with him on 20 January 2004, 25 May 2004 and 5 October 2004. Based on the plaintiff's clinical history, neurological review and physical examination, and reference to radiological material, Dr Kam formed the opinion that the plaintiff had a significant degree of lower back symptoms. He recalled saying words at the first consultation to the effect of the following: "To resolve your pain, your options are to lose weight, take up exercise and as a last resort undergo surgery. However, due to your significant weight, it will be in your best interests to attempt a significant weight reduction program before we consider any surgery." 29 Dr Kam then said that in accordance with his usual practice he counselled the plaintiff on weight loss measures. He went on to say words to the following effect: "You still need to lose more weight. You need to persevere with weight loss and continue losing as much weight as possible over the next 3 to 6 months before making a decision about surgery. With the weight loss, there is a good chance that your pain will improve to an extent that you could avoid any surgery. If there is no improvement in pain after your weight loss, then you may be a candidate for surgery. ***** In the event you need to proceed to surgery, I recommend a posterior lumbar interbody fusion and pedicle screw fixation of the L4-5 and L5-S1 level." 30 When consulted on 25 May 2004 the plaintiff told Dr Kam that he had lost five kilograms but still had a lot of pain in his back and legs. Dr Kam recalled telling the plaintiff the following things: "You still need to continue on your weight loss program and lose more weight. Any operation should be deferred for the moment because of your weight. If you lose more weight, there is a good chance that your pain will improve enough that you could avoid any surgery. If there is still no improvement in pain after your weight loss, then you will be a candidate for surgery. You should aim for a weight of at least 100 kilograms before we attempt any surgery." 31 Dr Kam next saw the plaintiff on 5 October 2004. The plaintiff described his condition and said that his pain was really bad and that he had not been able to leave the house or get out of bed to go to the kitchen. Dr Kam did not weigh the plaintiff at that time but recalls that the plaintiff had put on weight due to his immobility. Dr Kam said words to the following effect: "On account of the levels of pain you've described and the escalation of your back and leg pain, and your inability to mobilise around your house to get from your bedroom to your kitchen, we should consider proceeding with the surgery despite the fact you haven't lost enough weight yet. As discussed before, the surgery will involve a posterior lumbar interbody fusion … to be performed at Westmead Private Hospital." 32 At paragraph 29 of his statement Dr Kam dealt with what according to his usual practice he considered he would have said to the plaintiff at this time. That paragraph is as follows: "29. As at October 2004, it was my usual practice to use words similar to the following in effect when discussing the risks and providing warnings in relation to the performance of a L4-5 and L5-S1 posterior lumbar interbody fusion and pedicle screw fixation on an obese patient: 'Any surgery is accompanied by potential risks and complications. There are no guarantees with this surgery. There is a risk you could sustain a nerve root injury, which could leave you with a weakness in either or both of your legs after the surgery. There is a risk of spinal cord injury, which could affect both your legs. There is a risk you could develop bladder and bowel incontinence after the surgery. During the surgery, there is a risk of significant bleeding. If this occurs, you will require a blood transfusion. There is also a risk of you developing an infection, which is higher in your case due to your diabetes and morbid obesity. There is also the risk of hardware failure, and the risk that the pedicle screws inserted could loosen or fracture over time. If this occurs, you will require further surgery. Due to your weight and size, the operation will also take longer. Also, the extra weight will affect your rehabilitation after the operation and as a result, your recovery will be prolonged. If everything goes well, you will have a hospital stay of 7 to 10 days. Depending on your recovery, you could be discharged and can go home after that. You will then need to attend rehabilitation, for a period of 2 to 4 weeks. At best, you could possibly return to an office based employment in 10 to 12 weeks. Your rehabilitation could take longer for someone of your size. Even if the surgery goes smoothly and uneventfully, there is a chance that your back pain will not be resolved and will still be ongoing. In your case, I would estimate the probability of a successful outcome, being a significant decrease in your pain, to be about 70%'." 33 Dr Kam said that he then answered questions that the plaintiff and his wife had about the surgery. The plaintiff then told Dr Kam that he wanted to proceed with the operation. 34 Dr Kam agreed in cross-examination that if a patient is overweight it adds to the risks of surgery. He also knew that Drs Diwan and New had wanted the plaintiff to lose weight. He agreed that the plaintiff's operation time was extended because of his excessive weight and that in such circumstances, pressure is placed on the femoral nerves for much longer. He also agreed that the risk that there can be impairment to those nerves increases substantially in a six-hour operation compared to a four hour operation. This is because the pressure that may be exerted upon the nerves is applied over a longer period, not because the actual pressure is greater. However, greater pressure may be exerted upon the nerves if the patient is heavier. The plaintiff's submissions 35 The plaintiff contended that Dr Kam's warning was inadequate or insufficient to the extent that it neither warned of particular dangers associated with the plaintiff's weight, including especially the fact that the operation time would be extended because of it, nor of the chances of a catastrophic outcome. The plaintiff contended that his assessment of the risks of the operation could only be made with the benefit of information that included all of the risks associated with it. He put his case upon the basis that the scope and content of the warning were indivisible so that a failure to warn him of the possibilities concerning bilateral femoral neurapraxia could not be distinguished from, or diminished in importance when compared to, a failure or failures to warn him of far more significant adverse consequences such as paralysis or something similar. He emphasised that the notion of informed consent meant that there was no relevant adverse outcome that Dr Kam could responsibly fail to mention. In particular, the plaintiff submitted that this applied to all of the inherent risks of the operation, or those that could not necessarily be avoided even by the exercise of reasonable care and skill. Significantly, bilateral femoral neurapraxia was one of these. The plaintiff contended that he should have been, but was not, warned that his condition following the surgery could be worse than if he had had no surgery at all. Dr Kam's submissions 36 Dr Kam submitted that he gave his standard or usual warning to the plaintiff and that it was adequate in the circumstances. He contended, in effect, that even if he had not warned in terms of the possibility that the plaintiff could be worse, that concept or notion was nevertheless inherent in at least some of the serious adverse consequences of which he said he did warn. He agreed that he had not warned the plaintiff of the risk of bilateral femoral neurapraxia, but conceded that he should have. He submitted that applying s 5B(1)(c) of the Civil Liability Act, a reasonable person in Dr Kam's position would not have taken the precaution of administering the warning for which the plaintiff contended, having regard to the fact that the probability of harm was low and the likely seriousness of the harm was minimal: s 5B(2)(a) and (b). He submitted that it was "difficult to suggest that a patient in Mr Wallace's position would have attached significance to the risk". Credit 37 It will be apparent that there is a dispute between the plaintiff and Dr Kam about the nature and extent of the warning that was given. Mrs Wallace also gave evidence about this. In my assessment the plaintiff gave his evidence clearly and apparently truthfully. There was no attack upon his credit in any event. There was also no challenge to the truthfulness of Mrs Wallace. Dr Kam's version of what he told the plaintiff was challenged. He did however concede that he did not give, but should have given, a warning about the risk of bilateral femoral neurapraxia or local nerve damage. In the context of this case, that concession cast the balance of his evidence in a favourable light. To the extent that it is necessary to do so, however, I find that Dr Kam did not also warn the plaintiff of the risk that he could be left with weakness in either or both of his legs. The plaintiff denied that he had been warned of this risk. Mrs Wallace could not remember such a warning having been given. Dr Kam was not unreasonably forced to resort to what in his professional practice he considered or believed he would have said, rather than to an actual recollection about it. In the end result, the dispute is not significant because there is no controversy about Dr Kam's failure to warn the plaintiff of what in the events that have occurred has emerged as the only relevant warning and the plaintiff did not end up in a condition that was worse than he was before the operation. These concepts are also discussed in some detail below, in the context of the issue of causation. Consideration 38 Mr Sears and Mr Weaver are surgeons who were retained by Dr Kam and the plaintiff respectively to provide expert opinions and a joint report. This is referred to more fully later in these reasons. They gave concurrent evidence and were asked, among many other things, about whether or not they warned patients of the risk of neurapraxia. Their evidence was as follows: "HIS HONOUR: In either of your clinical and surgical practices do you give warnings to prospective surgical candidates of the side effects from neurapraxia? WITNESS SEARS: No, your Honour. WITNESS WEAVER: Not neurapraxia, but I would always tell the patient there is a potential for nerve damage. If people want to say what is nerve damage I could then go into the situation of saying, well, there's nerve damage ranging from 24 hour neurapraxia postoperatively to permanent impairment of nerve function. HIS HONOUR: We know thankfully in this case there was no operative nerve disruption. What I really wanted to know is, are your patients ever warned of the risk of posturally induced neurapraxia? WITNESS WEAVER: No. HIS HONOUR: Neither of you? WITNESS SEARS: If I see a patient who has described to me the condition that Mr Wallace was in and if I am contemplating the sort of surgery one certainly has to advise the patient of the risks of surgery, and I guess we all have our own kind of level to which we try to educate a patient, and it depends obviously on how much the patient wants to know and how much the patient is questioning. It also depends upon the circumstances. So if I have a patient who is pleading with me and is in terrible pain I will tell them about the risk of them being left worse off with the surgery, I will tell them about the risk of anaesthetic complications and dying, I will indicate the risk of paraplegia, talk about screw breakage, failure of the fusion to heal and having to do the operation again in six to 12 months, the risk of infection. I don't believe I have ever warned a patient about the risk of femoral neurapraxia. WITNESS WEAVER: I agree with all of that. So the general warnings and the general warnings can be taken to certain specifics, and amongst those specifics I would say there's a possibility of, as I said a few moments ago, nerve damage. If a patient then said what is nerve damage you can say, well, it can be temporary or permanent and if they said, well, what nerve can be damaged I would say, well, you can damage any of the major nerves, namely the sciatic, the obturator or the femoral nerves or any of the minor branches of any of those. But they would have to say to me, well, what are the chances that you are going to damage the femoral nerve or the lateral cutaneous nerve? They would have to ask me that question, I think." 39 Mr Sears later said he would tell patients "things which I think, if I told them that, they might say I'm sorry, the pain I've got, I wouldn't go ahead with the surgery, I don't want to risk it". Mr Weaver had this to say: "HIS HONOUR: Would you tailor your warning to the patient's needs and expectations as you perceive them rather than give a blanket warning to every patient regardless of their individual situation? WITNESS WEAVER: I would have a standard discussion, the fact that this is major surgery, and I would mention the specific major complications that Mr Sears has reported. As I was saying a little earlier, depending upon the circumstances of the individual patient if they want to know more I would tell them more, but I would at the same time become concerned regarding a patient who wanted to ask a hundred questions who was clearly indicating to me that he or she was probably not emotionally suited to this major surgery. ***** I would start with the issue of telling the patient that this is major surgery, there is a potential for certain significant complications, and I agree with every one that Mr Sears has just said. I would mention in that answer the possibility of nerve damage, and he has mentioned paraplegia. I would say there is a potential for damage to other nerves. Now, unless the patient specifically says 'what, are you going to damage my femoral nerves', that issue would probably not arise." 40 Mr Sears accepted the proposition that good neurosurgical practice in 2004 was to tailor the explanation to the patient rather than having some common warning given to all patients. He said, "I think that's what most surgeons would do". He said he believed that it was "good practice". 41 Dr Kam was also asked during cross-examination about his view of the specific issue of the need to warn about the risks of local nerve damage. His evidence was in these terms: "Q. I'm suggesting to you, sir, that your usual practice in dealing with an obese or morbidly obese man such as Mr Wallace was, should have included a specific warning about the risks of local nerve damage by virtue of the prolonged operating position for an extended period of time? A. Yes. Q. But in fact did not include that warning? A. Yes." 42 Mr Sears agreed that once an operation commenced, the risk of neurapraxia is an inherent and unavoidable risk of that surgery. He also agreed that the likelihood that an operation might lead to neurapraxia was directly related to the time that a patient spent on the operating table. There was no apparent controversy in these proceedings that a patient as heavy as the plaintiff would expect to be longer in surgery of the kind performed on him than equivalent surgery on a lighter person. Mr Sears was not prepared to say, however, that obesity per se increased the risk of neurapraxia apart from its relationship to the likely length of the operation. 43 The circumstances in which a doctor has a duty to warn a patient at common law is well established. In Rogers v Whitaker [1992] HCA 58; (1992) 175 CLR 479 at 490 the High Court said this: "The law should recognize that a doctor has a duty to warn a patient of a material risk inherent in the proposed treatment; a risk is material if, in the circumstances of the particular case, a reasonable person in the patient's position, if warned of the risk, would be likely to attach significance to it or if the medical practitioner is or should reasonably be aware that the particular patient, if warned of the risk, would be likely to attach significance to it." 44 In Rosenberg v Percival [2001] HCA 18; (2001) 205 CLR 434 at [60] – [61], Gummow J spoke of the identification of the risk: " The identification of the risk [60] It is established by Rogers that a medical practitioner owes a duty 'to warn a patient of a material risk inherent in the proposed treatment'. However, that proposition in turn poses further questions. [61] The first question is 'what "risk" is being spoken of here?' Put another way, it is 'what are the facts and circumstances, the possibility of the occurrence of which constitutes that "risk"?' Once that question is answered one may turn to consider whether the risk is 'material'. Where the action is brought in negligence and the plaintiff is seeking compensation for an injury suffered, the relevant risk is the possibility that the proposed treatment will result in the injury that in fact occurred. It is not, for example, the risk that the patient will make an uninformed decision or choose the wrong option, although that may well underpin the rationale behind the duty." 45 Reference should also be made to the dissenting speech of Lord Scarman in Sidaway v Board of Governors of the Bethlem Royal Hospital [1985] AC 871 at 876, cited with approval by Gleeson CJ in Rosenberg v Percival at [6] as follows: "[6] Rejection of the doctor's argument involved deciding not to follow the English decisions of Bolam v Friern Hospital Management Committee , and Sidaway v Governors of Bethlem Royal Hospital . This Court preferred the approach of Lord Scarman, who dissented in Sidaway , and who said: 'In my view the question whether or not the omission to warn constitutes a breach of the doctor's duty of care towards his patient is to be determined not exclusively by reference to the current state of responsible and competent professional opinion and practice at the time, though both are, of course, relevant considerations, but by the court's view as to whether the doctor in advising his patient gave the consideration which the law requires him to give to the right of the patient to make up her own mind in the light of the relevant information whether or not she will accept the treatment which he proposes.' (emphasis added)" 46 Sections 5O and 5P of the Civil Liability Act are relevant. Although their role and importance are not in contest, they were referred to by the Court of Appeal in Ambulance Service of NSW v Worley [2006] NSWCA 102 at [39] as follows: "[39] At least in relation to New South Wales, the reference to the statutory imposition of the Bolam test, or at least a variety of it, is contained in ss 5O and 5P of the Civil Liability Act 2002 (NSW). Those provisions maintain the dichotomy suggested in Rogers between a breach of duty to give a warning or other information, and other forms of professional negligence: the Bolam principle (in its statutory form) applies only to the latter. The Civil Liability Act does not, it should be noted, apply to the present case. However, the broader point made by McHugh J as to the nature of the exercise to be undertaken by the Court in assessing negligence by other professionals, is relevant." 47 What are the facts and circumstances, the possibility of the occurrence of which constitutes the relevant risk in this case? The risk was an inherent risk of the procedure. Moreover, it was a significant risk in this case because of the plaintiff's weight. This increased both the likelihood of the occurrence of bilateral femoral neurapraxia at all, as well as the extent and degree to which it might affect the plaintiff if it did occur. A warning tailored to an obese patient, such as the plaintiff, who was not only likely but probably certain to be in a prone operating posture for in excess of six hours, should have incorporated a reference to this condition and its potential to result from the surgery as an unavoidable risk. The relevant risk is the possibility that the proposed surgery in these circumstances may result in the neurapraxia that in fact occurred. 48 Was the risk material? This requires an answer to two further questions. Would a reasonable person in the plaintiff's position, if warned of the risk, have been likely to attach significance to it? Could it be said that Dr Kam was or should reasonably have been aware that the plaintiff, if warned of the risk of bilateral femoral neurapraxia, or its associated symptoms or consequences, would have been likely to attach significance to it? I consider that both questions should be answered yes. 49 It is not the same thing to say that, if the plaintiff had been warned of the risk but would nonetheless have proceeded to have the surgery, the risk was therefore not material. In other words, the decision that a particular patient may take when warned of the risk is not necessarily coextensive with or conclusive of a determination of the materiality of that risk. A particular material risk may persuade some prospective surgical candidates to proceed to surgery and take the risk, whilst others faced with the identical risk may not be prepared to do so. The inquiry at the breach stage is informed by the question of whether or not a reasonable patient in the position of the plaintiff would attach significance to the risk, not whether a reasonable patient in the position of the plaintiff would attach significance to the fact that the risk came home. A reasonable person in the position of the plaintiff would have been housebound and bedridden due to a combination of back pain and obesity for many weeks in the period leading up to the contemplated surgery. The prospect of any further, even if only but not necessarily temporary or transitory, interference with his mobility, would in my opinion be something to which he would in the circumstances of this particular case be likely to attach significance. 50 Dr Kam himself conceded that his usual practice in dealing with a morbidly obese man such as the plaintiff should have included a specific warning about the risks of local nerve damage by virtue of the prolonged operating position involved. This concession was in one sense no more and no less than a reasonable and proper recognition of the need to tailor the preoperative explanation to a patient, as opposed to the giving of a general warning, in the way recommended by Mr Sears and accepted by Mr Weaver. A person in the position of this plaintiff arguably approached the prospect of a posterior lumbar interbody fusion with a background that set him apart to a certain extent from the first time surgical candidate with no distinguishing idiosyncrasies. Dr Kam should in my opinion have formulated a warning of the risks confronting the plaintiff with an appreciation or at least an expectation that the possibility of local nerve damage with its associated symptoms or consequences was something to which he would be likely to attach significance. 51 In my opinion the plaintiff should have been warned of the potential risk of local nerve damage and/or of its associated symptoms or consequences. The failure by Dr Kam to do so in the circumstances of this case amounted to a breach of his duty to the plaintiff. I do not consider that a reasonable person in Dr Kam's position would not have taken the precaution of warning of the risk, even having regard to the probability of the harm of which Mr Sears and Mr Weaver both spoke. Because of the complex multifactorial condition or co-morbidities of the plaintiff, the likely seriousness of the harm was not necessarily minimal, even though it ultimately, but irrelevantly for present purposes, turned out to be so. The injury issue 52 Mr Hugh Weaver and Mr William Sears produced a joint report dated 14 May 2010 following a conference between them on that day. Mr Weaver is an orthopaedic specialist retained by the plaintiff. Mr Sears is a spinal neurosurgeon retained by Dr Kam. By reason of the way in which the issues in the plaintiff's case have become limited, much of the opinions expressed in the joint report are now not critical to the outcome in this case. However, to the extent that the joint opinion informs any of the remaining issues, it consists in the following series of questions and answers: 1. Was it reasonable to recommend surgery on 5 October 2004 given the symptomatology complained of by the plaintiff? We believe there was uncertainty regarding the likelihood of the [plaintiff's] symptoms being relieved by surgery. While a substantial body of Dr Kam's peers could have felt it appropriate to recommend surgery, a substantial body would equally have advised against surgery. 2. What alternatives to surgery, if any, were available as at 5 October 2004 to alleviate the plaintiff's pain and mobility problems? The plaintiff had undergone a wide and appropriate range of conservative treatments and we are unable to suggest any alternatives to surgery that might have been available as at 5 October 2004. 3. Was it reasonable to proceed to surgery on 21 November 2004? As stated above in question 1, we believe Dr Kam's peers would be divided in their opinion on whether or not it was reasonable to proceed to surgery. ***** 5 . What is the relevance of the nerve conduction studies of Dr Dowla and Dr Yiannakis? These studies do not support the contention that the plaintiff suffered neurological damage. 6. On the balance of probabilities, what is the cause of the plaintiff's lower limb weakness? We are unable to explain the plaintiff's lower limb weakness on an organic basis. 7. As at November 2004, was it accepted practice to perform a posterior lumbar interbody fusion at L4-L5 and L5-S1 with pedicle and screw fixation with the patient in the prone position? Yes. 8 . What, if any, damage was caused or contributed to by the plaintiff being in the prone position for the performance of posterior lumbar interbody fusion? We have no objective evidence of permanent damage having been caused by the plaintiff being in the prone position but updated nerve conduction studies/EMGs may help to clarify this point. 9. Should the plaintiff's obesity have meant that he was an unsuitable subject for surgery? Again, peer opinion would be divided on this issue. Some surgeons refuse to operate on obese patients while others are prepared to when conservative measures and attempts at weight loss have failed and they believe surgery has a reasonable prospect of helping severe and disabling symptoms. 53 For reasons that will become apparent, it seems clear that the only physical consequence of the plaintiff's surgery was the development and presentation of what has been described as bilateral femoral neurapraxia. In his report dated 18 August 2008 Mr Sears said the following about that condition and the plaintiff: "I suspect the [plaintiff's] sensory loss over the thighs may have been related to prolonged positioning on the operating table and causing a neurapraxia of the lateral cutaneous nerves of the thigh. The [plaintiff] was obese and with a prolonged surgical procedure this is a recognised complication of such surgery. The effects are usually temporary and have no effect on lower limb movement. In conclusion, I believe Dr Kam's handling of the plaintiff's surgery was standard and I can see no reason to believe that his care for the plaintiff was negligent. In particular, I have no doubt at all that the [plaintiff's] lower limb weakness following the surgery was not caused by any nerve root compression by an epidural haematoma or other fluid collection." 54 As part of their concurrent evidence Mr Sears and Mr Weaver described the plaintiff's condition as follows: "WITNESS SEARS: Neurapraxia is a temporary malfunction of a nerve following injury, usually traumatic injury. In the case of Mr Wallace, a period of pressure applied to the nerve which has temporarily caused that nerve to function or not function. Neurapraxia is not a permanent injury. So I guess where we wrote 'These studies do not support the contention that the patient suffered neurological damage', that might be more correctly stated permanent neurological damage. WITNESS WEAVER: I agree entirely, yes. ***** HIS HONOUR: Speaking of patients generally, is bilateral or unilateral femoral neurapraxia a common incident of surgery performed in the prone position? WITNESS WEAVER: Not common, but it is a recognised complication. It would be fairly uncommon, I would I would have said. WITNESS SEARS: I think it is a recognised complication, if you like. Is it common? I'm not sure. As I say, I don't use the Jackson table. I do use it from time to time. In all of the fusions which I have done, which would be over a thousand, I have seen one case where it was quite apparent. Having said that, when one operates on patients and the duration of the surgery is long, it is not uncommon that they will wake up with some numbness on an arm or numbness on the hip or some other neurapraxia which almost always recovers, so it may not always be the lateral cutaneous nerve of the thigh or the femoral nerve." 55 The witnesses later agreed that neurapraxia is a transient episode of motor paralysis with varying rates of recovery depending upon the significance of the insult in the first place. 56 Dr Dowla, a consultant in neurology and clinical neurophysiology at the hospital, examined the plaintiff following the surgery. In particular, he made a record of his examination of the plaintiff on 1 December 2004. After setting out the results of his examination he expressed the following conclusions: "The manifestation is typical of bilateral femoral neurapraxia. He is likely to improve in the next few weeks. However EMG study is valuable to establish diagnosis and prognosis. The optimum timing for EMG would be 10-14th December 2004. I will arrange." 57 There is no evidence that the plaintiff underwent any further EMG until shortly before 25 February 2005. Dr Dowla's conclusions at that time were expressed as follows: "Conclusion: Apart from an absent left sural and a small right sural and sensory action potential indicative of peripheral neuropathy but no other abnormality has been found. There is certainly no evidence of active denervation and the interference pattern was reduced in the left lower limb muscles, mainly quadriceps, tibialis anterior and gastrocnemius. This does not support any definite neuropathic abnormality . Opinion: His current neurophysiological finding is out of proportion to his physical manifestation . . ." (emphasis added) 58 There is some doubt about whether or not Mr Sears and Mr Weaver agreed that the plaintiff had sustained a bilateral femoral neurapraxia during his surgery. Mr Weaver accepted that he had but Mr Sears was not convinced. He expressed this view during cross-examination: "I am unable to correlate in my own mind an ongoing severe weakness of hip flexion with a femoral neurapraxia, given that hip flexion is a relatively weak function of the muscles supplied by the femoral nerve and the dominant hip flexors, muscles called the iliopsoas which are not supplied by the femoral nerve. It is that disconnect between the described severity and weakness of hip flexion and the diagnosis of a femoral neurapraxia which I cannot put together. ***** I also think that while there may, and I wouldn't disagree that there could have been some degree of femoral neurapraxia, but I am not convinced that there was and I certainly believe that the duration of that neurapraxia was short. By that I mean it ended before February or whenever this report was written, because I do not feel that you could - I do not believe that you could have a significant femoral neurapraxia and have normal electrophysiological findings. For me those two are inconsistent." 59 Mr Sears was also asked to consider the relationship between the possible presence of a bilateral femoral neurapraxia and the fact that the plaintiff's symptoms persisted following his recovery from the post-operative effects of the epidural. He said this: "BATES: Just make the assumption that Dr Kam agreed in evidence that after he waited long enough for the anaesthetic to wear off that really there was no significant change at all, the clinical picture remained the same right up until the time that he was transferred to St Joseph's hospital on 3 February, in the sense that he had a second operation. In other words, after the anaesthetic wore off after the first operation, from then to the second operation and after the second operation when the anaesthetic wore off and onwards, I want you to assume that the evidence from Dr Kam was that the clinical picture remained the same. WITNESS SEARS: Yes. BATES: If you just make that assumption, would you then concede that it is more probable than not that he was still suffering the bilateral femoral neurapraxia, perhaps in combination with a lateral cutaneous element as well, at least up until the time he was discharged from the Westmead Private Hospital and transferred to St Joseph's on 3 December 2004? WITNESS SEARS: If his neurological picture was unchanged more than some hours following the administration of the local anaesthetic through the epidural, I cannot explain the picture entirely based on the epidural. It suggests something else is going on. All my other comments, though, still hold. I cannot explain the clinical picture on the basis of a femoral neurapraxia. I can certainly understand the numbness in the side of the thighs through a neurapraxia of the femoral cutaneous nerves." 60 This is to be compared with the opinion of Mr Weaver, also given during the experts' concurrent evidence: "BATES: So do I understand from your last comments in response to his Honour that it is your opinion that there was a probable bilateral neurapraxia, and in reaching that diagnosis you are taking account of both the clinical findings and the neurophysiological findings? WITNESS WEAVER: I am trying to and, as I said, I find it difficult to correlate the two. Yes, I have said I think there was some nerve problem initially. The word damage has got to be it used very carefully. I don't think there was any permanent damage caused, no." 61 In the final analysis, Mr Sears appears ultimately to have capitulated on this point when cross-examined by counsel for the plaintiff. His relevant answer was in these terms: "WITNESS SEARS: So that given the medical examination is an inexact science at its best, I would agree that the clinical picture here is suggestive of a femoral neurapraxia because of the relatively normal or only slightly weak ankle movements, the power of pulling the feet up and down. In my experience for a patient to pretend to be weak and to restrict it just to knee extension and hip flexion and not the feet, I have never seen anybody do that. So I think that this is suggestive that on 1 December there was a femoral neurapraxia present." 62 However, on the assumption that the plaintiff did sustain a bilateral femoral neurapraxia during his surgery, there remained a clear disagreement about how long it persisted. Mr Sears was of the opinion that Dr Dowla's conclusions in February 2005 did not support the existence of a bilateral femoral neurapraxia in February 2005. Mr Weaver considered that it did. Their evidence about this was respectively as follows. "HIS HONOUR: What, if anything, does that tell us about the period between the date of that report and the operation in late November, the previous year? WITNESS SEARS: If there had been a femoral neurapraxia then it appears to have recovered completely by the time of February 2005, based on the electrophysiological evidence. WITNESS WEAVER: I'm the not, I don't have that in front of me and I just had a feeling there was some point in time when it was suggested that the quadriceps - there is a reduced recruitment pattern, again I'm not an expert in EMG so I have to be careful here but I do take Mr Sears' point about that conclusion, that, the actual verbal description there. I'm, I accept the proposition that the EMG study as reported suggests certainly it is unlikely, or there is not, there is no evidence of active denervation and this certainly suggests from the viewpoint of a permanent situation that there is no denervation. But again we come back to this question of whether, during the period of some months, postoperatively there was a temporary problem which even the EMG studies are not showing." 63 Mr Weaver later gave evidence that he thought there were consistent findings early on and that he thought they were becoming inconsistent by February. The passage of the evidence where this is to be found is as follows: "HIS HONOUR: My question to you was, what, if you could just give the answer, what if anything do you glean from the 10 February 2005 document from Dr Dowla about the accuracy of that diagnosis that he earlier made? WITNESS WEAVER: It is becoming less consistent. Because earlier I would accept and held and still hold the view that there was some femoral nerve involvement. By this, 10 February, these clinical findings are of concern because they are all over the place. I mean there are easily separate major nerves we are talking about here instead of just the femoral nerve. HIS HONOUR: He suggested there was a femoral neurapraxia as at 1 December. WITNESS WEAVER: Initially, yes. HIS HONOUR: What I want to know is does anything he says on 10 February tell you whether or not that was correct and, if it was correct, does anything he said on 10 February tell you about whether or not it still exists? WITNESS WEAVER: It doesn't really say anything about the initial period. He is speaking as of 10 February. The second part of your question suggests that by 10 February findings are becoming inconsistent. I think there were consistent findings early on and I think they are becoming inconsistent by February. HIS HONOUR: Mr Sears? WITNESS SEARS: I would agree with that." 64 However, Mr Weaver and Mr Sears were in complete agreement that there was no evidence to support the continued presence of bilateral femoral neurapraxia by 3 June 2005 upon which date Dr Dowla reported once again. His conclusion at that time was as follows: "The study shows further improvement of the interference pattern bilaterally but they are still reduced as shown in the previous EMG. There was certainly no evidence of active or chronic partial denervation. This is reassuring." 65 Mr Sears and Mr Weaver were both in agreement that they had not seen anything indicating permanent damage. 66 In my opinion, the answer to the question posed by the injury issue is yes. I consider on the balance of probabilities that the plaintiff sustained bilateral femoral neurapraxia following the first operation. It may not have been life threatening, it did not persist for very long and it was certainly not permanent, but whatever may have ailed the plaintiff before the operation, he certainly did not suffer from this condition. The neurapraxia only manifested itself when the plaintiff regained consciousness following the operation. There is expert agreement that lying in a prone position for the six hours or more that it took to perform the operation quite evidently caused it. 67 Furthermore, the second operation was a consequence of the first operation and was damage or harm caused to the plaintiff in the sense contemplated by the authorities and the Civil Liability Act. Dr Kam did not contend otherwise. Indeed, even though the original surgery was performed in a technical sense without fault, the post-operative condition of the plaintiff necessitated further surgery at the site of the original surgical wound. This was in large measure due to the fact that the plaintiff's post-operative signs and symptoms, analysed with the benefit of objective studies, did not adequately permit a definitive diagnosis to be made. In those circumstances, a second operative procedure presented itself as the only method to confine and explain the plaintiff's condition and to guide the course of his post-operative care thereafter. 68 Nor can it be said that bilateral femoral neurapraxia, or a second operation, either taken alone or taken together, are harm that could only be described as de minimus. Dr Kam sought to argue that it could. The latter issue has emerged with an unusual significance in this case having regard to the fact that the damages have been agreed and that I can have no part to play in their calculation or assessment if the plaintiff becomes entitled to a verdict. The plaintiff does not, on ordinary principles, become entitled to the agreed damages unless and until he proves all of the necessary elements of his cause of action. In the present case it is clear or at least arguable on the evidence that the bilateral femoral neurapraxia actually sustained by the plaintiff was not as significant as it might have at one time appeared. In the events that have occurred, and in the light of the evidence as it has unfolded, particularly the joint opinion of the experts, the agreed damages are on one view disproportionate to the plaintiff's actual loss. For this reason in particular the defendant has argued, and the plaintiff has contested, that the plaintiff has not proved that he has sustained any loss that is sufficient to consummate his cause of action. 69 It will be apparent that I consider that the plaintiff has established that he suffered harm as a consequence of the operation that is sufficiently serious to complete his cause of action. To adopt the terminology utilised by counsel in this case, the plaintiff suffered harm that was not simply de minimus. I consider that the bilateral femoral neurapraxia by itself was sufficient for this purpose. The added element of the second operation puts the matter beyond doubt. The causation issue 70 This issue falls to be determined having regard to answers to the following questions: (a) Civil Liability Act s 5D(1)(a): was Dr Kam's negligence a necessary condition of the occurrence of the harm ("factual causation")? (b) Civil Liability Act s 5D(3): what would the plaintiff have done if Dr Kam had not been negligent? In particular: (i) Would the plaintiff have declined to undergo the operation if he had been warned of all relevant risks of the operation taken together? (ii) Would the plaintiff have declined to undergo the operation if he had only been warned of the risks associated with the incidence of bilateral femoral neurapraxia taken alone? (c) Civil Liability Act s 5D(1)(b): is it appropriate for the scope of Dr Kam's liability to extend to the harm so caused ("scope of liability")? (The need to consider this question at all is dependent upon the answers to the preceding questions). 71 In considering these questions I have had regard to what was said by the High Court in Adeels Palace Pty Ltd v Moubarak [2009] HCA 48; (2009) 239 CLR 420 at [41] – [45] as follows: "Causation [41] The first point to make about the question of causation is that, in these cases, it is governed by the Civil Liability Act. [42] Section 5D(1) of that Act divides the determination of whether negligence caused particular harm into two elements: factual causation and scope of liability. [43] Dividing the issue of causation in this way expresses the relevant questions in a way that may differ from what was said by Mason CJ, in March v Stramare (E & M H) Pty Ltd , to be the common law's approach to causation. The references in March v Stramare to causation being 'ultimately a matter of common sense' were evidently intended to disapprove the proposition 'that value judgment has, or should have, no part to play in resolving causation as an issue of fact'. By contrast, s 5D(1) treats factual causation and scope of liability as separate and distinct issues. [44] It is not necessary to examine whether or to what extent the approach to causation described in March v Stramare might lead to a conclusion about factual causation different from the conclusion that should be reached by applying s 5D(1). It is sufficient to observe that, in cases where the Civil Liability Act or equivalent statutes are engaged, it is the applicable statutory provision that must be applied. [45] Next it is necessary to observe that the first of the two elements identified in s 5D(1) (factual causation) is determined by the 'but for' test: but for the negligent act or omission, would the harm have occurred?" 72 The question of what the plaintiff would have done if Dr Kam had not been negligent is a matter that is to be determined subjectively in the light of all relevant circumstances: s 5D(3)(a). The exclusion of liability in negligence for harm suffered as a result of the materialisation of an inherent risk found in s 5I(1), does not apply to the particular circumstances of the present case: s 5P. Assessment of the plaintiff as a patient and as a witness is critical at this stage of the inquiry. The plaintiff's evidence 73 The plaintiff was cross-examined concerning his condition and state of mind before the operation. Some of that cross-examination is as follows: "Q. You had worked with that pain management centre in an effort to try and reduce your pain? A. Yes. Q. You had had some difficulty attempting to reduce your pain, hadn't you? A. Yes. Q. You had also attempted to deal with some physiotherapy specifically directed to your pain? A. Yes. Q. That hadn't assisted either, had it? A. Not greatly, no. Q. You were taking more and more medication to lesser effect, correct? A. I was, as time progressed Dr Gronow was increasing, as far as I can remember, the Baclofen I was taking. ***** Q. You were desperate for some relief from your pain? A. Yes. Q. Because you could hardly walk? A. I was able to walk with the aid of a walking stick. Q. The reality is that your ability to walk around had been severely compromised by the pain in the lower back? A. Yes. Q. When you saw Dr New, spinal surgeon, in December 2003, that was in relation to the pain that you were suffering in your low back? A. Yes. Q. You had a discussion with Dr New about attempting some conservative measures to reduce your pain? A. Yes. Q. One of those things was to try and reduce your weight? A. Yes. Q. In that conversation with Dr New he said to you, didn't he, that if those conservative measures are unsuccessful you will have to consider surgical intervention? A. Yes. Q. Slightly prior to that conversation with Dr New did you prepare a two page document and send it to him setting out some of the problems you were then having? A. Possible, yes. He may have asked me to do that, yes." 74 The plaintiff was referred to the terms of that letter dated 24 November 2003 and he agreed he had written it to Dr New. The letter was in these terms: "Dr New Owing to a tendency to forget particulars or to omit certain details I thought it would be expedient to set down in writing the various issues I would like to raise at this consultation. For near to six months now I have been shunted between various medical practitioners, hospitals, specialists, physiotherapists and other health care providers. Needless to say the cost has been extensive. Please do not get me wrong. I believe that specialists more than deserve every cent they earn considering the extensive training undertaken and the long and ungodly hours worked. The problem is not there. Unfortunately my coffers have a limit and with my diminished earning capacity I am taking out more then [sic] I am putting in and consequently the supply is almost exhausted. I would not mind so much except for the fact that despite the cost there has been no improvement in my condition, on the other hand the symptoms have regressed. I started off walking independently albeit awkwardly. I progressed to a costume walking stick, then a proper walking aid and it has now been suggested that I require two proper walking aids. This is as a result of constant falls, particularly negotiating the carpeted stairs in my home. The pain management personnel were very good insofar as it related to advice in pain management, walking posture and programming my working day. To help me cope I have been prescribed Oxycontin (10mg 2 x 24) Endone (5mg 3 x 24) Epilum (2 tablets 2 x 24) Tofranil (25mg daily) and recently Baclofen has been added to the list. I have also been prescribed a sleeping tablet Temazepam which I very seldom take as it makes me feel terrible on the following day. Understandably I am walking around in a perpetual daze and I am extremely wary about taking the medication when I have to drive. Quite obviously I am absolutely fed [sic, up] with having to take the medication. Incidentally, I was also advised to buy a 'TENS' machine which I have done and use regularly. You have asked me to lose weight and this issue I have vigorously addressed. I have cut down my food intake by about 60% and my consumption of alcohol by about 50%. When I saw you I told you I weighed 110kgs. I came home and weighed myself the same day and noted my weight to be actually 125kgs. By the same scales I am now down to 111kgs. Progress is still being made in this regard. The fact of the matter is I am not getting any better. The inability to do tasks is a source of constant frustration. I feel inadequate and useless and it particularly angers me that I cannot go about my daily business. I am self-employed and need to work because the bills still keep coming in. I need to know what the prognosis is for me. I need to have some time frame I can work to, I need to have some goal to aim for. At the moment I am floating around in a sea of uncertainty with no end in sight. Could you please advise me as to what you perceive the plan of management to be for the immediate future as well as what conclusion you are anticipating. Thank you for taking the time to read this note." 75 The plaintiff was then shown a copy of a four page letter that he agreed he had sent to Dr Kam before the operation. It did not become evidence but the plaintiff was cross-examined about it as follows: "Q. When you presented this four page document that I took you to a moment ago to Dr Kam, you described chronic low back pain, particularly evident even after moderate walking activity? A. Yes. Q. With pain radiating down your legs? A. Yes. Q. Correct? A. Yes. Q. Right into your feet, extending to your toes? A. Yes. Q. Medication was only providing you with temporary relief? A. Yes. Q. You described yourself as having severe restrictions in movement? A. Yes. Q. And this was causing you significant stress and anxiety? A. Yes. Q. To the extent where you had bouts of depression? A. Yes. Q. Because of your uncertain future? A. Yes. Q. In the very last line of that letter what you say in your summary is that remedy or relief in some form or to some extent is highly desirable, correct? A. Yes. Q. That was why you went to see Dr Kam, wasn't it? A. Yes. Q. You were looking for assistance to try and do something about the unremitting pain, correct? A. Yes. Q. You were looking to try and get some assistance because you could barely move, correct? A. Yes. Q. You wanted to explore further what might be available? A. Yes. Q. On your evidence that took place after Dr Diwan had already told you that a form of surgery he proposed might be risky, correct? A. Yes." 76 A little later the plaintiff gave this evidence: "Q. By the time you had seen Dr Kam on the second occasion, you were desperate for relief, weren't you? A. Yes. Q. You could hardly walk, correct? A. Yes. ***** Q. You anticipated that there was surgery that would have to come forward, correct? A. I knew something was going to happen, whether it was surgery or not. If it is written there I said surgery, that would be right. Q. By September 2004 you had tried everything that the doctors had asked you to do, hadn't you? A. Yes. Q. And none of it had worked, had it? A. No. ***** Q. I will do this in short form. I don't wish to upset you unnecessarily, but in March of 2004 did you tell your general practitioner that you were having suicidal thoughts? A. Yes. Q. And as you've already told his Honour, the fact of your continuing pain and the immobility was causing you to feel depressed, wasn't it? A. That and other matters as well. ***** Q. Dr Kam then had a discussion with you about the options that were available to you at that point back in January 2004, didn't he? A. Yes. Q. He suggested that one option was to lose weight? A. Yes. Q. You had had some difficulty losing weight over the years, hadn't you? A. Yes. Q. He told you that you might want to take up some exercise? A. Yes. Q. And that the last resort was to undergo surgery? A. Yes." 77 When the plaintiff saw Dr Kam on 5 October 2004 he told him that he had been unable to leave the house for four weeks and could not even get out of bed to go to the kitchen. He agreed that he had been largely confined to bed for four weeks prior to 5 October 2004 and agreed that most of his activities for those four weeks were confined to his bedroom as a result of the pain he was suffering and his inability to move about. 78 He gave this evidence: "Q. At this stage you were in pretty desperate straits, weren't you? A. I was in a lot of pain, yes." Consideration 79 The applicable test for causation at common law was described by McHugh J in Rosenberg v Percival at [24] – [25] as follows: " The test for causation where there has been a failure to warn a patient of risks [24] Under the Australian common law, in determining whether a patient would have undertaken surgery, if warned of a risk of harm involved in that surgery, a court asks whether this patient would have undertaken the surgery. The test is a subjective test. It is not decisive that a reasonable person would or would not have undertaken the surgery. What a reasonable person would or would not have done in the patient's circumstances will almost always be the most important factor in determining whether the court will accept or reject the patient's evidence as to the course that the patient would have taken. But what a reasonable person would have done is not conclusive. If the tribunal of fact, be it judge or jury, accepts the evidence of the patient as to what he or she would have done, then, subject to appellate review as to the correctness of that finding, that is the end of the matter. Unlike other common law jurisdictions, in this field Australia has rejected the objective test of causation in favour of a subjective test. [25] It follows from the test being subjective that the tribunal of fact must always make a finding as to what this patient would have done if warned of the risk. In some cases where there is no direct evidence as to what the patient would have done, the judge may infer from the objective facts that the patient would not have undergone the procedure. In exceptional cases, the judge may even reject the patient's testimony as not credible and then infer from the objective facts that the patient would not have proceeded. The judge might find, for example, that the patient was a person whose general credibility was so poor that no reliance could be placed on that person's oral evidence. Yet, notwithstanding the rejection of the patient's oral testimony, the judge might infer that nevertheless this patient would not have undergone the procedure. That inference would ordinarily be based not only on the objective facts but also on the tribunal's assessment of the general character and personality of the patient." 80 It is also important to have regard to what was said by Gummow J in Rosenberg v Percival at [83] – [84] as follows: " Causation [83] The question of whether a failure to warn of a material risk was causative of the plaintiff's injury involves two distinct levels of inquiry. At the first level, the risk must be related in a physical sense to the injury that was suffered. Thus, a medical practitioner will not be held liable for the failure to warn a patient of a material risk of damage to 'her laryngeal nerve', if the injury that eventuated resulted from a misapplication of anaesthetic. This is so despite the fact that the patient would not have had the treatment and therefore would not have suffered the injury from the misapplication of anaesthetic if the patient had been warned of the risk to "her laryngeal nerve". This can be seen as an example of a situation where the application of the 'but for' test would lead to an unacceptable result. [84] At the second level, there must be a causal connection, in the legal sense, between the failure to warn of the material risk and the occurrence of the injury. Cases involving a failure to warn of a risk encounter difficulties of causation that do not arise in cases of, for example, a negligent physical act "causing" injury. The failure to warn the patient of the risk can never amount in the same sense to the cause of the injury. Moreover, the issue of failure to warn usually arises when the performance of the physical cause of the injury was not negligent. Indeed, the present is such a case, given the finding that the appellant conducted both operations upon the respondent with the required skill and care." 81 This is re-emphasised by his Honour at [86] in these terms: "[86] In this case the purpose of the relevant rule is that stated in par (vi) of the extracts from the joint judgment in Rogers which have been set out above. This imposes an obligation upon medical practitioners adequately to warn their patients of the consequences of the treatment they are contemplating. If the medical practitioner should fail to warn the patient of a particular consequence and that consequence in fact eventuates then, subject to the question of materiality, the rule seeks to hold the medical practitioner liable for that consequence." (emphasis added) 82 A determination of whether or not the plaintiff would have gone ahead with the surgery if adequately warned requires a consideration of what he was told and what he was not told but should have been. When that exercise is performed in this case it is apparent that there are few differences between what the plaintiff says and what Dr Kam says, and only one difference between them with any potential significance. 83 The plaintiff could not remember whether Dr Kam told him that there was a risk that he could have an injury to his nerve roots. Dr Kam said that that was part of the warning he gave in such cases as part of his usual or standard practice. The plaintiff denied that he had been told that he could be left with weakness in either or both of his legs. Dr Kam's standard warning included a reference to this. They were also in disagreement about whether Dr Kam warned of spinal cord injury, which could affect both of the plaintiff's legs. The plaintiff emphatically denied that he was warned of the possibility of bladder or bowel incontinence. He said in fact that Dr Kam only mentioned that as a possible consequence of not having the surgery. Dr Kam's standard practice was to warn of these possible complications. The plaintiff denied that he was warned that he was subject to a greater risk of infection because of his weight or that there could be a failure of the hardware. Dr Kam said otherwise. The plaintiff could not remember whether Dr Kam warned him that the screws could loosen or fracture. The plaintiff could not remember whether Dr Kam had told him that there could be no guarantees. 84 The plaintiff agreed that he had been told that there was approximately a 70 to 75 per cent chance of the operation being successful and a 25 to 30 per cent chance that the surgery would be unsuccessful. He complained that he was led to understand that the concept of a 25 to 30 per cent unsuccessful outcome was coextensive with an outcome in which he was not better but was not worse than before the operation. He argued that the operation in fact left him in a worse condition and that if he had been warned of the risk of that possibility he would have declined the operation. 85 In my opinion this contention is without any relevant content. This is for at least two reasons. First, in my opinion the plaintiff is not worse off than he was before the operation. The condition in which he now finds himself falls squarely within the plaintiff's own preoperative understanding of the 25 to 30 per cent chance that the operation would be unsuccessful. In other words, the risk that the plaintiff might be worse off following the surgery did not as a matter of fact materialise. In this regard it is to be recalled that the plaintiff was preoperatively confined to bed or at least to his home environment. His weight gain was related to this period of impaired mobility for some many weeks. This is to be compared with his current condition, which included his ability to attend court and give evidence, albeit with the aid of a mobile walker. 86 However, critically for present purposes, the plaintiff is not worse off as the result of anything that eventuated from the surgery. The plaintiff's ability to rely upon a contention that he became worse following his operation must be directed to demonstrating a condition that became manifest as a post-operative consequence, and he cannot rely upon the continued disabling condition in which he found himself before the operation. In this case the only post-operative consequence for the plaintiff was the presentation of bilateral femoral neurapraxia. That condition has entirely resolved. The medical information about the plaintiff contained in the tendered material dealing with the period up to the present suggests that the plaintiff is disabled in a complex and serious way but that his condition is a function of a number of factors, none of which is the result of the surgery performed by Dr Kam or the plaintiff's decision to submit to it. The plaintiff's condition at present is the result of the continuation and possible worsening of his still unresolved preoperative co-morbidities to which the various experts have referred. 87 Although it is not a matter that is determinative of any view I have formed in this case, the plaintiff's evidence about this is to some extent contradictory. For example, he contended that he would not have had the surgery if he had been told that the 25 to 30 per cent lack of success figure incorporated the possibility of being worse off. However, he was prepared to agree that it was obvious that if the hardware failed in any way, further surgery would be required. He agreed that he "perfectly well knew" that there could be further surgery if things did not go well. These concessions appear to me to include recognition that a further operation fell within the 25 to 30 per cent assessment. Acceptance of the possibility of the need for a corrective surgical procedure rather suggests to me that there was also an acceptance by the plaintiff that he could have been worse post-operatively than if he wholly declined the surgery. 88 Of the warnings about which there is any dispute, only the warning concerning the possibility that the plaintiff could be left with weakness in either or both of his legs, and which became manifest as bilateral femoral neurapraxia or local nerve damage, can have any present relevance. No other warning, about the giving of which the plaintiff and Dr Kam agree or disagree, is connected to any risk that materialised. In this case the relevance of weakness in either or both of the plaintiff's legs must be understood to be a reference on the plaintiff's case to a temporary or transitory condition. That is because the evidence, to which I have earlier referred, demonstrates that any leg weakness (or similar condition) that afflicted the plaintiff after the operation was of short duration and was not explicable on a neurological basis within days or at best weeks thereafter. It has long since resolved and is not present now. A warning of that injury or consequence, however described, is the only possibly relevant warning for the purpose of deciding whether the plaintiff would have proceeded with the operation. 89 In this respect Mr Sears expressed the following opinion in his report dated 3 June 2010: "… I can see no objective evidence of any permanent damage having been caused by the plaintiff being in the prone position for the performance of the posterior lumbar interbody fusion." 90 Mr Weaver was of the same view, which he set out in his report dated 15 June 2010: "… I note that the assessment of Mr Wallace's problem seems to be that there is no convincing evidence, either from clinical examination or from recent EMG studies, to suggest that he has incurred any actual neurological impairment involving his lower limbs. … there seems no evidence to suggest that Mr Wallace has sustained any permanent neurological damage as a consequence of having been obliged to lie in the prone position for a prolonged period during the operation." 91 In my opinion the plaintiff would not have declined the surgery if warned of the possibility of this condition in general or specific terms as a risk of the surgery he was contemplating. This is so in my opinion whether the risk is characterised as a risk of bilateral femoral neurapraxia, local nerve damage, weakness in either or both of his legs or in general terms that he could be left temporarily worse off with a condition fitting these descriptions. This is for the following reasons. 92 As the result of his preoperative condition, as described by him, the plaintiff was desperate for some form of pain relief. He had attended a pain management centre in an effort to try to reduce the pain in his back and legs. He agreed he had had some difficulty attempting to do this. He had tried physiotherapy but this had not helped. He was taking more and more medication with no corresponding benefit. He could only walk with the aid of a walking stick. No conservative measures had worked. Dr New had foreshadowed the need for surgery. The plaintiff was "absolutely fed up with having to take medication". He was in a perpetual (medicated) daze. He told Dr New that the fact of the matter was that he was not getting any better. He felt inadequate and useless. He had severe restrictions in movement. This was a cause of significant stress and anxiety. He had bouts of depression because his future was uncertain. He approached Dr Kam for assistance to try to do something about unremitting pain, because he could barely move. Dr Diwan had told him that surgery might be risky. He agreed Dr Kam had told him the same thing. By the time he saw Dr Kam for the second time "he was desperate for relief". He could hardly walk. He had tried everything and nothing had worked. He had even had suicidal thoughts. To the suggestion that he was in desperate straits, he agreed he was in a lot of pain. The last resort was to undergo surgery. 93 A key to understanding what the plaintiff would have done if warned of the risk that in fact materialised is to compare the plaintiff's condition before the operation with the effects of the bilateral femoral neurapraxia itself. There is in my opinion no comparison at all. In a report dated 26 November 2004 addressed to Dr Kam, Dr Awad referred to the bilateral femoral neurapraxia and indicated that the plaintiff's "power in his legs is slowly improving and he has some anti-gravity movements and he has been slowly mobilised with the physiotherapists". As earlier recorded, Dr Dowla found that by 25 February 2005 the objective neurophysiological evidence did not support the existence of any definite neuropathic abnormality. 94 In my opinion, having regard to his desperate preoperative plight, the plaintiff would not have declined the proposed surgery upon the basis of a possible risk of the condition that he suffered in fact. The prospect for this plaintiff of some mild and temporary interference with power and sensation in his lower limbs is out of all proportion to the disabling and distressing condition from which he hoped Dr Kam's surgery would provide a cure or at least some relief. It is to my mind inconceivable, or at the very least highly unlikely, that the plaintiff would have hesitated for a moment to submit to a procedure which he knew to be attended by all of the risks Dr Kam said he informed him of, as well as the risks of which on my finding he should have been informed, in circumstances in which he was in a desperate search for relief from unremitting pain, when there was a 70 to 75 per cent chance of some relief and when the relevant cost to him may have been a mere temporary loss of power and sensation in his lower limbs of the nature, extent and duration of the condition that materialised. 95 Although, as I have found, the plaintiff would have undergone the surgery even if warned of bilateral femoral neurapraxia or local nerve damage, the plaintiff contended that if he was entitled to be, but was not, warned of some risk that would have led him to decline the surgery, he is legally entitled to complain about the consequences of any risk that eventuates, even if that specific risk would not by itself have led him to do so. In this case that translated to a proposition that if the plaintiff would have declined the surgery if warned of some catastrophic outcome of which he was not warned, but which did not materialise, but would not have declined the surgery if warned of bilateral femoral neurapraxia, which did materialise, he is entitled to succeed because the latter condition was caused by the very fact of an operation he would have declined if properly warned. 96 The only potentially relevant failure to warn in this case was the failure to warn of bilateral femoral neurapraxia, or what is more likely to have been described as local nerve damage. The legal cause of that condition in the plaintiff could never be the failure to warn of some other risk that did not materialise. It is important to bear this in mind because the plaintiff's case and his evidence about this issue was to some extent directed to the alleged significance of failures by Dr Kam to warn him of possible catastrophic consequences associated with known risks of the procedure that he contended would have dissuaded him from proceeding with the surgery if they had been drawn to his attention. However, the passage from Rosenberg v Percival cited above in the judgment of Gummow J makes it clear, if it were not otherwise so, that a failure to warn of a consequence or risk that would, for the sake of the argument, have led the plaintiff to decline the surgery, is not relevantly causative of harm suffered if the surgery proceeds unless that actual risk materialises. Conclusions 97 I find for these reasons that Dr Kam's negligence was not a necessary condition of the occurrence of the harm suffered by the plaintiff. I find that if Dr Kam had not been negligent, the plaintiff would nevertheless have proceeded to undergo the posterior lumbar interbody fusion that Dr Kam performed. In the circumstances, the question of whether or not it is appropriate for the scope of Dr Kam's liability to extend to the harm suffered by the plaintiff does not arise. Decision 98 There will be a verdict for the second defendant with costs. ************* DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.