Knott v Newham Healthcare NHS Trust

1. LORD JUSTICE THORPE: Lord Justice May will give the first judgment.

2. LORD JUSTICE MAY: This is an appeal from a decision and order of Simon J given on 16 October 2002. Hale LJ gave permission to appeal on some, but not all, of the grounds of appeal. The claimant was aged 36 or thereabouts at the time of the trial. She had spent all her working life as a nurse. She was aged about 32 when the incident giving rise to these proceedings occurred in March 1998. She claimed against the defendants, the Newham Health Care NHS Trust, her former employer, damages for personal injuries which she contended were caused during the course of her employment at Newham General Hospital. She had worked as a nurse since the age of about 18. She worked at various hospitals and through various grades of employment from January 1987. She started employment with the defendants in January 1996. With them she worked in Newham General Hospital on the Beckton Ward, an acute medical ward which catered for highly dependent patients. In January 1998 she was employed as a junior sister or charge nurse with responsibility for caring for such patients including those suffering from HIV. In practice she was in charge of the ward when she was on duty. From at least September 1997 but probably before, there were acute shortages of staff in the hospital, particularly trained staff. This affected the whole hospital trust. It affected Beckton Ward in particular. It was the claimant's case that she was required to carry out lifting of patients without appropriate equipment, assistance and training, and that this caused the injury which was the subject of the proceedings.

3. On 11 March 1998 she had worked on the early shift on Beckton word. She went home early. On the following day she had a bath and slipped slightly as she was getting out. She spent the rest of the day in bed. On the following morning she woke with a severe pain in her back. She had suffered, as was common between the parties, damage to intervertebral discs at T12/L1 and L1/L2 and neural damage. She subsequently had to undergo two operations and has suffered and continues to suffer considerable pain and discomfort. She claimed that the defendants had no proper or adequate system or training for manually handling patients, they had inadequate lifting equipment, with the result, she claimed, that she was exposed to the risk of back injury she in fact suffered from this cause.

4. The claimant's case was that although she suffered what she described as "aches and pains" and "complete body ache" at the end of her shifts she did not feel symptoms associated with back pain until January 1998. She then had to lift a particular long-term brain injured patient a number of times in the course of the day. She described what happened in March 1998 and subsequently. Her symptoms included lower back pain, sensory disturbance extending to her legs, urinary incontinence and an inability to sit still for more than 15 minutes. In March 1999 she had her first operation at the Royal London Hospital. This involved decompression of the affected discs with a combined anterior and posterior fusion. After this operation her symptoms improved. She was still in some pain but was able to walk and sleep properly. She was advised that she could not have children and still had to wear incontinence pads. By January 2000 the lower back pain was improving. Her sensory disturbance was limited to a lack of orgasm during sexual intercourse but she was able to sit properly for more than 15 minutes at a time. However, during the summer of 2000 she started to experience increased pain which by September 2000 became acute. An x-ray showed that screws in the metal work in her spine inserted at the first operation had broken. She had to have a further operation in November 2000.

5. The defendants accepted that there was pressure on the staff on the Beckton Ward. However their case was that the claimant had exaggerated the amount of manual lifting which she did. Such lifting as she did do was not heavy and continuous or likely to cause damage to her back. The defendants' case was that the claimant suffered from constitutional degenerative disc disease unrelated to her work and that the symptoms from which she suffered were triggered by the slip getting out of the bath on 12 March 1998. Their case, as described by the judge in paragraph 22 of his judgment, was that disc protrusion occurred spontaneously due to the natural progression of her degenerative disc disease.

6. The first issue which the judge considered was whether the defendants were in breach of their statutory or common law duty owed to the claimant. This depended largely on whether the defendants operated an appropriate system for lifting patients in the Beckton Ward. Much evidence was directed to this issue which the judge decided in the claimant's favour. He found that the defendants did not operate an appropriate system for lifting patients in the Beckton Ward. He also found that no real steps were taken to reduce the risk of injury to their employees to the lowest level reasonably practicable in the relevant period. So far as Beckton Ward was concerned there was no adequate response to the duties imposed by the Manual Handling Operations Regulations 1992.

7. The judge then proceeded to make findings as to the amount of lifting the claimant actually carried out as to which there was a dispute. He was not satisfied that an expert analysis carried out on behalf of the claimant was accurate in that it significantly over-estimated the lifting tasks carried out by the claimant. That was not, however, to say that the claimant did not carry out lifting tasks. She did so as part of her general nursing care of her patients. The defendants' submission that the claimant had carried out minimal lifting tasks was not helped by the fact that they had failed to carry out any assessment. Having heard the witnesses the best (but necessarily imprecise) assessment that the judge could make was that the claimant regularly carried out some lifting tasks during each shift that she worked in the course of 1997 and that after September 1997 the heavy lifting tasks increased. This assessment was qualified by the fact that the claimant only worked 97 shifts in the period 14 August 1997 to 12 March 1998. The first proposed grounds of appeal sought to challenge parts of these factual findings, but Hale LJ refused permission to appeal on those grounds.

8. The judge then considered the cause of the claimant's injuries as to which there was a sharp divergence between the parties. The claimant had given a history of her symptoms to her GP, the consultants who saw her and the experts who examined her. This account was, said the judge, plainly relevant to the issue of causation. The judge accepted the claimant's evidence that she was suffering from backache before she took her bath on 12 March 1998, although she may not have appreciated the significance of this. The claimant may have initially thought that her injuries were due to the slip, but the judge said that she is not a doctor and the expert opinions were inherently likely to be more reliable as to the cause of her injuries. The judge accepted her evidence that in the period March 1997 to March 1998 she had undertaken more lifting than normal and that many of the patients had been heavy and dependent. This was subject to two qualifications. First, the lifting burden was more concentrated in the period beginning September 1997. Second, the lifting burden should not be over-stated for the reasons which the judge had already set out. The judge did not accept the claimant's evidence that she developed low back pain and aching in the spine during the period of nearly a year before March 1998. She undoubtedly suffered from whole body ache at the end of shifts but she did not develop low back pain during the year before March 1998. The judge did, however, accept her evidence that she suffered from back pain after lifting a paralysed and totally dependent patient in January 1998. He also accept that she was suffering from back pain before she took her bath on 12 March 1998.

9. The judge then referred to the expert witnesses called on each side. These were Mr Rushman for the claimant and Mr Pooley for the defendants, each of them consultant orthopaedic surgeons; and Professor Swash, Professor of Neurology and Consultant Neuro-surgeon for the claimant and Mr Sinah a Consultant Neuro-surgeon for the defendants. All experts agreed that at March 1998 the claimant was suffering from long-standing degenerative deterioration to the lumber spine in the region of T12/L1 and L1/L2. The experts disagreed, however, as to the cause of the claimant's injuries.

10. The judge then summarised in paragraph 51 of his judgment the respective views of the experts in the following terms:

"i) The view of the Claimant's experts was as follows:

a) the Claimant's degenerative disease had been advanced by the process of lifting during employment with the Defendant.

b) there had been a protrusion of the T12/L1 and L1/L2 discs on or about 12th March, which was directly attributable to the lifting.

c) This protrusion had caused damage to the conus (the base of the spinal column) and the adjacent nerve roots.

d) The damage to the conus or surrounding nerves had caused the Claimant's neurological symptoms.

ii) The view of the Defendant's experts was as follows:

a) The degenerative changes were the cause of the Claimant's symptoms, including the neurological symptoms.

b) These degenerative changes developed many years before March 1998 and were not affected by the lifting the nature of the Claimant's work.

c) the Claimant's back was unstable and the slip getting out of the bath triggered the Claimant's injuries.

d) There was no evidence of significant disc protrusion and no evidence of consequent injury to the conus."

11. The judge then considered a radiologist's report of an MRI scan of the claimant's back taken on 22 April 1998 (that is five or six weeks after the critical episode in the case). He quoted from the radiologist's report as follows:

"... there are disc bulges seen at T12/L1, L1/L2 and L5(S1) levels.

The canal is generous in proportion and there is no evidence of any focal neural compression at any level. The Conus appears normal. No explanation for the symptoms seen."

As I read that radiologist's report of that MRI scan, it gives no support for any explanation for the defendants' experts opinion as to the cause of the neurological symptoms from which, as will appear, the claimant was suffering.

12. The judge then discussed the expert evidence and reached his conclusion in the following paragraphs:

"53. The evidence of Prof Swash (who is Professor of Neurology and a consultant Neurologist at the Royal London Hospital) was that the neurological symptoms could only be explained by some degree of damage to the conus. His evidence was that compression of the conus, if lasting longer than 6-24 hours, would cause permanent neurological injury. Although there was no clear image of disk impingement, this could have been due to the supine position of the [claimant] when the image was taken or to the desiccation of the protruded disc material. It was his firm view that, in the light of the symptoms and the disc pathology, the only explanation for the neurological symptoms was compression to the conus. It was suggested to him that the Claimant's neurological symptoms might have been caused by some movement of the vertebrae or boney spurs when she slipped getting out of the bath. He rejected such an explanation. In his view this could not happen.

54. I accept the evidence of Prof Swash on this point. He gave his evidence ... in a clear and measured way and did not attempt to argue the case. As well as being particularly well qualified to give expert opinion on the point, he had carried out a full neurological examination of the Claimant. This revealed absence of anal reflex bilaterally which was only consistent with damage to the conus.

55. I the accept evidence of Mr Rushman and Prof Swash that the most likely cause of the compression of the conus was a protrusion of the adjacent discs (bulging of the posterior side of the disc annulus which impinged on the conus). I regard the Defendant's suggestion that the neurological symptoms were unrelated to the disc damage as being unlikely.

56. The Claimant's degenerative disc disease rendered her particularly vulnerable to disc prolapse. The lifting that she carried out on Beckton Ward would have significantly loaded her lumbar spine and advanced the likelihood of disc protrusion in this area. There was a degree of common ground as to the propensity of nurses to suffer disk prolapses due to the nature of their work. Prof Swash, Mr Rushman and Mr Pooley all agreed that nurses lifting in an unnatural way such as is likely to cause injury to the back; and lifting is widely regarded as a major cause of disc prolapse in nurses. As Mr Rushman put it: nurses lift differently, they have to arch their backs forward to get into position. This causes disc bulging; and damage may be caused by further loading.

57. The Claimant had two specific bouts of backache (while lifting patient M and on 11th March 1998) that were, in my judgment, directly related to lifting work and were indicative of deforming changes in the structure of the spine.

58. It is impossible precisely to determine the progression of the Claimant's disc failure. However, in my view, the lifting of patients by the Claimant during the period of her employment with the Defendant is likely to have damaged the annulus of the discs posteriorly. The damage may have repaired itself; but the annulus would have been progressively weakened thereby increasing the likelihood of a disc protrusion and further injury. The disc prolapse and neural damage was the eventual result of this process.

59. It follows that, in my judgment, the Defendant's breach of duty caused (and, at the very least, materially contributed to) the Claimant's injury."

The remainder of the judgment concerned issues of damages as to which there is no appeal.

13. The written grounds of appeal may be summarised as follows. First, the judge's findings as to causation were contrary to the medical evidence and inconsistent with contemporary medical documents. The evidence of Professor Swash and Mr Rushman assumed that the claimant had been required to undertake heavy lifting tasks on a regular, continuous and persistent basis, and that she had experienced back symptoms during the period preceding March 1998. Neither assumption was borne out by the evidence. Second, the judge failed to give "any consideration whatsoever" to the medical evidence called on behalf of the defendants. Third, the judge failed to consider the likely progression of the claimant's back condition if she had not slipped in the bath on 12 March 1998 and failed to take account of the fact that she had worked as a nurse for 11 years before her employment with the defendants and that during these employments she had also engaged in lifting patients. This was likely to have contributed to her condition in March 1998. The defendants were not wholly responsible for the condition of her back then. Accordingly the judge should have apportioned liability in order to reflect the contribution of previous periods of employment to her eventual condition.

14. Mr Spencer QC on behalf of the defendant/appellant submits that the claimant had a degenerative back at the relevant levels before she started employment with the defendants. The issue was whether this was caused by her work. The claimant, he submits, did not have symptoms indicating back trouble before 12 March 1998. The judge's finding on this issue was that she did not suffer low back pain or any back pain between March 1997 and March 1998 except for the occasion when she was lifting a patient in January 1998 and on the day before she slipped. The immediate cause of her neurological symptoms had to be something which happened on 12 March 1998.

15. Mr Spencer has referred us to the detail of accounts she gave to doctors and others after the March 1998 incident. He was inclined to challenge the finding that she had back pain on 11 March immediately before the slip in the bath incident, but accepted eventually that the judge's finding on that subject was available on the evidence. It accorded with the claimant's own evidence and with some, if not the majority, of her subsequent accounts, for example that which she gave to Mr Pooley. The submission is rather that the judge failed properly to analyse this part of the defendants' evidence.

16. Mr Spencer submits that all the experts agreed that the degenerative condition of her back had been present before she was employed by the defendants and had been long-standing. The opinion as to causation of the claimant's experts assumed a history of regular and continuous heavy lifting in the year leading up to March 1998. They also assumed that she had suffered low back pain over that period. Mr Rushman, for instance, agreed that if she had no symptoms before her slip this would present a different picture to that presented by her to him.

17. Mr Spencer has taken us through passages in the evidence of Mr Rushman and of Professor Swash. In particular he has referred to a passage towards the end of Professor Swash's evidence where he was asked what his opinion would have been if there had been no heavy lifting and, as Miss Foster asked:

"If you were also to take away the history of back symptoms... that she relayed to you, you would similarly be less confident about your conclusion ..."

- to which he said:

"No, I would be very puzzled indeed. It is because here is a situation in which the imaging shows a chronic lesion, not an acute one. In the context you have just put to me that would have to be an acute conus lesion, and an acute disc, and that is not the situation."

18. All experts were agreed that a lifting related injury at T12/L1 and L1/L2 was most unusual, and that the result of excessive lifting would normally be expected to strain the lower back in the area of L4/L5. Mr Spencer submits that if the claimant's experts are correct in their analysis it must follow that lifting over on extended period before she was employed by the defendants must be causally relevant. The defendants' experts considered that the claimant's degenerative disease and the onset of her symptoms were due to spinal degeneration unrelated to physical exertion. They rely on the history of her condition, radiological evidence and their experience of this type of condition in clinical practice. Mr Spencer submits that the judge preferred the claimant's expert but without any proper analysis of the opinions of the defendants' experts and without taking into consideration that the factual basis of their opinions was not established. He ought to have rejected those opinions and accepted those of the defendants' experts. He submits further that there is no mention in the judgment of the point made about nurses who suffer from back trouble from lifting normally suffering it in the lower back area (that is around L4 and L5) and that the judge failed to take account of that fact in his consideration of which of the opinions as to causation should be preferred. The submission is that this court should so conclude and accordingly dismiss the claim. In the alternative there should be a retrial on the medical issues based on the judge's findings of fact because it is submitted the judge failed to express any sort of analysis of the conflicting expert evidence. The further alternative submission (which I will come to in greater detail in a moment) is that heavy lifting during earlier employments must have been a contributing cause for which the defendants cannot be liable. The judge, as he was invited shortly to do by Miss Foster, should have apportioned liability by reducing the contribution of the defendants. There was an alternative written submission not pursued orally that the judge should have concluded that the defendants' breach of duty only advanced in time the onset of a condition which would have occurred anyway and damages should have been awarded on that basis. But as I say that last was not pursued.

19. On behalf of the claimant/respondent Mr McCaul has submitted in writing that the judge did not conclude that the claimant's back had become degenerative as a result of her employment with the defendants between March 1997 and March 1998. All experts were agreed that she was suffering from long-standing degenerative deterioration to the lumbar spine. Her case was, and the judge concluded, that lifting patients during the period of her employment with the defendants damaged the annulus of the disc posteriorly, progressively weakening the annulus with disc prolapse and neural damage eventually resulting. The defendants' submission fails, says Mr McCaul, to distinguish between disc degeneration and disc prolapse. Mr Rushman described disc degeneration in his evidence as involving three stages. It may start spontaneously. Then the disc is narrowed or flattened to the extent that the facet joints tend to overlap rather like loose tiles on a roof giving rise to pain. At the third stage the structure stiffens up and, although there is less movement geometrically,the person has no pain and feels better. Without loaded flexion placed on the claimant's lumbar spine by the awkward and heavy lifting of patients while employed by the defendants the claimant would have progressed to stage three and her job would have been unaffected. Without the stresses and strains during that employment, Mr Rushman reckoned that there would have been minor degenerative changes but no particular symptomatic problem. He was sure that she would not have run into this catastrophic episode. In contrast disc prolapse occurs when the annulus partially tears and the disc material bulges outwards near the spinal chord nerves that run down the back. The opinion of the claimant's experts, accepted by the judge, was that the lifting of patients had caused the annulus of the disc to weaken progressively and to an extent that it was so susceptible to damage that it needed only the incident in the bath to lead to prolapse of an extent that caused compression of the conus. Mr McCaul submits that the grounds of appeal are wrong to say that the assumptions underlying the opinions of the claimant's experts did not accord with the judge's factual findings. Professor Swash assumed that the claimant had undertaken frequent heavy lifting. The judge found in terms that the claimant regularly carried out some heavy lifting tasks during each shift that she worked during the course of 1997, and that after September 1997 the heavy lifting tasks increased. This was qualified by the fact that she only worked 97 shifts between 14 August 1997 and 12 March 1998. As to backache before she slipped in the bath, Mr McCaul submits that the judge accepted that she had two specific bouts of backache, one in January 1998 and the other on 11 March 1998, which were directly related to lifting work. She also suffered from whole body ache. Professor Swash had indicated in answer to a question from the judge that he did not think it was fully understood why some people experience pain with the spinal pathology and others do not. He had also addressed a phenomenon of whole body ache during the course of his evidence.

20. Mr McCaul submits that it is quite wrong to say that the judge failed to give any consideration to the opinions of the defendants' experts. Indeed he set them out in paragraph 51(ii) of his judgment, which I have already quoted. Having set out the conflicting views, it is submitted that he clearly and adequately stated his reasons for preferring the evidence of the claimant's experts. In any event, the parties having heard the evidence given at trial and submissions made, were quite able without difficulty to follow his reasoning. Mr McCaul points to his cross-examination of Mr Pooley to indicate that Mr Pooley accepted much of the basis of the claimant's case.

21. As to the other grounds of appeal, Mr McCaul submits that both sides had agreed that this was not an acceleration case. The claimant's case was that her disc prolapse was caused by heavy lifting while she was employed by the defendants. The judge so found. The cause of the entire history of the claimant's back condition may well have included lifting in previous employments. But the cause of the annulus becoming so weak as to lead to disc prolapse was the lifting in the defendants' employment. There can be no suggestion, he submits, that this was a divisible injury. The judge's conclusion that the defendants' breach of duty caused or, at the very least, materially contributed to her injury was quite sufficient to establish liability.

22. There are thus, in summary, three main strands for consideration by this court. Mr Spencer puts as his main submission on liability and causation the point that the factual findings which the judge made as to lifting on the one hand and the extent of back pain suffered by the claimant before March 1998 on the other, made it incumbent on the judge to investigate with care what had become a very much more complicated case for the claimant's experts. The factual judgment, submits Mr Spencer, undermined the factual basis for their opinion. The second main strand is that the judge gave inadequate analysis to various parts of the case in his judgment and failed to give adequate reasons for the conclusion which he reached. In particular, it is submitted that he failed adequately to analyse and deal with the expert evident called on behalf of the defendants. The third main strand concerns the issue of contribution.

23. It is appropriate to refer to the second of those strands before dealing with others and to consider the decision of this court as to the adequacy of judges' reasons in English v Emery Reimbold & Strick Ltd [2002] 1 WLR 2409. In that decision, a judgment handed down by Lord Phillips MR, consideration is given to the previous decision and judgment of Henry LJ in Flannery v Halifax Estate Agency Ltd [2000] 1 WLR 377. Suffice for present purposes to record that the Master of the Rolls in the English case refers both to Strasbourg jurisprudence under Article 6 and to the requirement to give reasons under the common law. As to the Strasbourg cases he said this (in paragraph 12 of his judgment):

"The Strasbourg Court, when considering article 6, is not concerned with the merits of the decision of the domestic court that is under attack. It is concerned to see that the procedure has been fair. It requires that a judgment contains reasons that are sufficient to demonstrate that the essential issues that have been raised by the parties have been addressed by the domestic court and how those issues have been resolved. It does not seem to us that the Strasbourg jurisprudence goes further and requires a judgment to explain why one contention, or piece of evidence, has been preferred to another. The common law countries have developed a tradition of delivering judgments that detail the evidence and explain the findings in much greater detail than is to be found in the judgments of most civil law jurisdictions. We do not believe that the extent of the reasoning that the Strasbourg court requires goes any further than that which is required under our domestic law, which we are about to consider."

Then from paragraphs 15 to 21 Lord Phillips deals with the requirement to give reasons under the common law. Having referred to a number of decisions, he said in paragraph 16:

"We would put the matter at its simplest by saying that justice will not be done if it is not apparent to the parties why one has won and the other has lost."

He then cited from the judgment of Griffiths LJ in Eagil Trust Co Ltd v Pigott-Brown [1985] 3 All ER 119 at 122 where Griffiths LJ had said that he could not stress too strongly that there is no duty on a judge, in giving his reasons, to deal with every argument presented by counsel in support of his case. It is sufficient if what he says shows the parties, and if need be the Court of Appeal, the basis on which he has acted. In paragraph 18 Lord Phillips said that the observations of Griffiths LJ apply to judgments of all descriptions." He then referred to the practical requirements of our appellate system and said in paragraph 19:

"... if the appellate process is to work satisfactorily, the judgment must enable the appellate court to understand why the judge has reached his decision. This does not mean that every factor which weighed with the judge in his appraisal of the evidence has to be identified and explained. But the issues the resolution of which were vital to the judge's conclusion should be identified and the manner in which he resolved them explained."

Mr Spencer relies on that case. Mr McCaul submits that the judge in all respects in this judgment measured up to it.

24. Before dealing with the first of Mr Spencer's submissions, that is to say the factual basis upon which the claimant's experts had given their opinion had changed and required reinvestigation, it is appropriate to look at some of the medical evidence. The medical issue of causation had crystallised at a joint experts' meeting between Mr Rushman and Mr Pooley on 22 August 2002. They had a long agenda of questions which they systematically answered. They agreed that disc protrusion at T12/L1 and L1/L2 was not common. They agreed that heavy lifting could be a precursor to it, and that heavy lifting of difficult dependent patients could damage this part of the back. Mr Rushman considered that it was unlikely to occur in the absence of heavy stresses. Mr Pooley considered that Mrs Knott's disc protrusion happened spontaneously and he noted MRI evidence of chronic changes in the discs involved. They considered that the claimant was a highly motivated and well meaning nurse and that she was involved in excessive lifting activities on the ward. They believed that her back had been more uncomfortable for the previous day or two. They related the increased symptoms for the heavy lifting involved with ward duties. Mr Rushman believed that this activity was responsible for disc protrusion. Mr Pooley believed that the disc protrusion had occurred spontaneously due to the natural progression of degeneration of disease in a constitutionally predisposed individual. He believed that Mrs Knott's work was not causally related to this protrusion. Both experts agreed that a slight slip, as described, was unlikely to cause a disc protrusion. They agreed that the slip in this case may have been the final event in an already damaged disc. Mr Rushman considered that if it were not for heavy lifting there would have been no protrusion and Mrs Knott would still have been working as a nurse. Mr Pooley considered that the natural progression of degenerative changes in her lumbar spine which were exacerbated by twisting injury outside work had prevented her from continuing her nursing career. Answers to other questions were essentially to the same respective effect. In answer to the question "what is the cause of the claimant's neurological symptoms including sphincter problems and the perineal insensitivity?", the experts disagreed. This was in the event critical to the judge's decision as to causation. Mr Pooley considered that there was no direct relationship between Mrs Knott's back problem and her neurological symptoms. He considered that no organic pathology which would account for her genitourinary symptoms had been found. Mr Rushman believed that there were strong circumstantial evidence to suggest that the conus of the spinal chord was damaged by disc protrusion. He accepted that the disc protrusion is seen on the MRI scan as adjacent to the dura in the capacious spinal canal. Damage to the conus itself may not have been seen on the MRI scan. He felt that this geometry could have changed with,for example, the combination of flexion and loading of the weakened disc. It is well known that conus is very sensitive to pressure and damage could have occurred. In the period up to the MRI scan the geometry could have changed due to a combination of positional pressure on the disc and possibly some desiccation to give the scan appearance. He felt that the time relationship of the thoraco-lumbar skeletal problem and urinary symptomatology suggested that both elements occurred simultaneously. He noted that both neurologists and urologists accepted that there had been damage to the conus as a basis of these problems. Finally for present purposes, both experts agreed that Mrs Knott had degenerate changes in her spine before 13 March 1998.

25. The court had two written reports from Mr Rushman following examination of the claimant on 22 January 1999 and 13 November 2001. In paragraph 21 of his second report he expressed his opinion as to causation as eventually reported in the joint report of the experts' meeting. In paragraph 24 he was asked to comment on the entries of Mrs Knott's GP records for 13 March and 25 March 1998 and a record made on 1 July 1998. These entries were consistent with Mrs Knott's statement that she slipped while having a hot bath to relieve her back pain. Mr Rushman agreed with the orthopaedic surgeon's report of 13 April 1999 that if the injury was solely as a result of a slip in the bath then a different pattern of damage would have occurred. He agreed that the prolapsed disc was related to over-use and over-strain of the back.

26. Mr Pooley made a report following examination of the claimant on 18 February 2002 in which he expressed an opinion as to causation consonant with that recorded as being his in the experts' report. In a letter dated 18 March 2002 he commented on a report of Professor Swash. The essential view expressed in the letter is that, contrary to Profession Swash's opinion, the MRI scan demonstrated degenerative changes in certain intervertebral discs but there was no evidence that disc prolapse due to an episode of trauma had occurred. There was no evidence that either spinal cord or nerve roots were involved by prolapsed disc material to an extent that would cause bladder or other organ dysfunction.

27. Profession Swash wrote three reports following examinations on 2 February 1999, 19 May 2000 and 4 February 2002. His essential neurological opinion was that conveyed by Mr Rushman following the joint expert meeting. He referred to the MRI scan as showing disc protrusion at T12/L1 and L1/L2 which impinged upon and deformed the theca, but did not cause cord compression or conus compression. His clinical conclusion was that Mrs Knott had suffered a disc prolapse at these levels, with compression of the conus medullaris, causing urinary and anal sphincter difficulties, pelvic sensory disturbance with loss of orgasm, a sensory disturbance extending from T12/L1 over the whole right leg and into the sacral segments, but relatively sparing S1. There was particular involvement of the L4 and L5 nerve roots suggesting that there may have been direct compression of these roots by the disc material. Clinical examination also showed evidence of a conus lesion and that the knee jerks were very brisk and that the ankle jerks were reduced.

28. Mr Sinah gave a report dated 8 September 2002. He had not examined Mrs Knott. He had reviewed various documents and reports including the operation notes of 8 March 1999 and x-rays and MRI scans which he described. His interpretation of the films was that the claimant had evidence of chronic degenerative spinal disease at T12 and L1. He felt that the degeneration did not occur in a short period of time but rather was likely to have been developing over some years previously. He was not convinced that the MRI scans of 22 April 1998 confirmed the presence of an acute soft disc prolapse at L1/L2 or T12/L1. In his opinion the degenerative changes would not have occurred within a relatively short period of time. He felt that the imaging prior to her original surgery was not that of an acute soft disc prolapse, but demonstrated chronic degenerative lower dorsal and upper lumbar spinal disease affecting both discs and bony components of the spinal canal and that it was constitutional.

29. This evidence was given and supplemented by oral evidence at the trial. We have been referred to passages of the oral evidence on which the parties rely. In essentials the experts did not depart from the views which they had expressed in their written reports although there was some modification in some respects.

30. Professor Swash wrote a letter dated 4 October 2002 in which he commented on Mr Sinah's report. Professor Swash suggested that Mr Sinah had not seen his (Professor Swash's) medical notes and that he may have been unaware that there were neurological abnormalities consistent with conus/couda equina disease. He suggested that Mr Sinah's attention should be drawn to the neurological features to which Professor Swash had referred. Profession Swash then wrote this:

"The neurological abnormalities are incontrovertible evidence of damage to the conus/couda equina. In the clinical context, and in the light of the imaging the only explanation of these abnormalities, which cause serious and disabling symptoms, as described by Mrs Knott, and related in my reports, is that there was compression of this region by discal protrusion."

He then proceeded to explain, essentially as related by Mr Rushman at the joint experts' meeting and as recorded by the judge in his judgment, why this may not have been evident on the MRI scan. He concluded his letter as follows:

"Mr Pooley... has selectively quoted my correspondence, and imputed views to me that I do not hold. For the sake of simplicity, it should be noted that Mrs Knott has clinical disabilities, and findings on neurological examination, consistent with conus lesion, and it is my opinion that these are commensurate with the level of the discal disease. They can only be explained by a period of conus compression. Unfortunately, as is so often the case, they have proved to be irreversible."

31. Thus the medical issue as to causation may, with reference to these reports and letters, be simply stated. In the opinion of Mr Rushman and Professor Swash the claimant suffered the acute consequences of disc prolapse resulting in damage to the conus/couda equina and caused by heavy lifting at work. In the opinion of Mr Pooley and Mr Sinah her symptoms resulted from a degenerative spinal condition unrelated to her work. This opinion was supported in the negative sense by their view that the MRI scans of 22 April 1998 did not show disc prolapse or damage to the conus. Nor, however, as I pointed out earlier in this judgment, did the MRI scan support their opinion as to causation. On one view the radiologist's report which the judge quoted tended to negative that opinion. Professor Swash explained why the MRI scans may not have shown this, but pointed to what he referred to as incontrovertible neurological evidence in support of his opinion. In effect, he challenged Mr Sinah to give an explanation for the neurological symptoms which Mr Pooley had failed to do at the joint experts' meeting.

32. The substance of all this is contained in the judge's judgment. I have quoted the relevant passages. It is a judgment which is economically expressed but in this instance in my judgment economy is a positive virtue. A quick reading might suggest that it is short on content, but a more careful reading shows that almost every sentence contains more compressed content than at first appears. I reject the appellant's submission that the judgment as a whole does not address the factual issues arising from the accounts which the claimant gave after the event. It does so in terms, albeit briefly. In effect the judge took account of and accepted the points made, but made factual findings available on the evidence as a whole.

33. I reject the appellant's submission that the judgment does not address the defendants' case as to causation; it does so in terms in paragraph 51 of the judgment, which I have already quoted. I reject the appellant's submission that the judgment does not give adequate reasons for preferring the claimant's medical experts. The judge in substance accepted Professor Swash's explanation for an absence of disc prolapse on the MRI scans and accepted his opinion that the neurological symptoms could only be explained in the way in which Professor Swash had explained it. Professor's Swash's challenge to produce an alternative explanation was not in substance met and a decision in consequence in favour of the claimant on this issue which in condensed form was capable of being shortly expressed was entirely understandable and would have been understood by the parties. Indeed, as I read the passage in the oral evidence of Mr Sinah to which Mr Spencer referred us (section G3 page 92) he went a good way to accepting Professor Swash's view, and little or no way to propounding an alternative. We were also referred to the evidence of Mr Pooley where Mr Spencer accepted that the witness made concessions in this respect. There is, in my judgment, no proper criticism to be made in general terms of this judgment by reference to Flannery v Halifax Estate Agencies and English v Emery Reimbold , to which I have already referred. There are, it is true, on examination, some rough edges. For instance there is no mention of the point made about the greater likelihood of nurses suffering damage from heavy lifting suffering that damage in the lower back in the area of L4 or L5 and not at the higher level that this claimant suffered her injuries. Nevertheless in my judgment that omission, if omission it be, does not render the reasons given by the judge inadequate. This was, after all, a case where it was common ground that the claimant had suffered her injuries at the higher T12/L1 and L1/L2 level. Indeed there was no doubt that the operations that she had to undergo were at that level.

34. As to other grounds of appeal although the judge did not accept the over-blown version of the extent to which the claimant engaged in heavy lifting before 12 March 1998 as propounded by an expert on her behalf, the judge did make findings open to him on the evidence, that she had engaged in regular heavy lifting which, it has to be remembered, constituted a now unchallenged breach of duty owed by the defendants to her. The extent of the heavy lifting which the judge found, although less than the claimant claimed at trial, was in my view entirely sufficient to support that element of the claimant's expert opinion. It was I think consistent with Mr Rushman's understanding that we have been taken through during the course of the day and it was not materially less than that of Professor Swash. It was admittedly less than that which the expert had propounded at trial, but that mere fact did not, in my judgment, undermine that particular basis of the opinion of the experts. It was quite close to that which they had understood in their written opinions. In addition, there were incidents of back pain before 12 March 1998, and I do not consider either that the judge can be faulted in holding that there was such an incident on 11 March 1998, which Mr Spencer was inclined to attack; nor was he obliged to reject the opinions of the claimant's experts on this ground alone.

35. I come to the question of contribution which I readily say has caused me some hesitation. The factual case put by Mr Spencer is as follows. The claimant was 32 at the time of her injury. She had been a nurse since the age of about 18, with heavy lifting more or less throughout that period, although there were some periods in the early to mid-1990s when she did only some or no lifting. The claim relates, submits Mr Spencer, to a maximum of one year out of about 12, although in fact the lifting found by the judge went back to the beginning of 1997. Mr Spencer submits that all 12 years would have contributed to the event which took place in March 1998 on the judge's finding of fact. There was, it is agreed, long-standing degenerative changes. A short submission was made to that effect to the judge without particular reference to the case of Holtby (to which I will come in a moment) but he did not deal with it. Mr Spencer refers to evidence from Mr Rushman relevant to the question of contribution to the effect that all the working history would contribute to the claimant's degenerative condition. So, submits Mr Spencer, there should have been an apportionment. He refers in particular to paragraph 58 of the judge's judgment which I will read again:

"58. It is impossible precisely to determine the progression of the Claimant's disc failure. However, in my view, the lifting of patients by the Claimant during the period of her employment with the Defendant is likely to have damaged the annulus of the discs posteriorly. The damage may have repaired itself; but the annulus would have been progressively weakened thereby increasing the likelihood of a disc protrusion and further injury. The disc prolapse and neural damage was the eventual result of this process."

The judge said that the defendants' breach of duty caused, and, at the very least, materially contributed to, the claimant's injury.

36. The case of Holtby [2000] 3 All ER 221 421 is a decision of this court by a majority of two to one (as to reasons). The leading judgment was given by Stuart Smith LJ. The claimant had been exposed to asbestos dust while working for several years as a marine fitter. The judge found that his condition would have been less severe if he had only sustained exposure to asbestos dust while working for the defendants. He had previously worked for other companies. It was held that, where a claimant suffered injury as a result of exposure to a noxious substance by two or more persons but claimed against one person, that person would be liable only to the extent that he had contributed towards the disability. The claimant had to prove that the defendant was responsible for the whole or a quantifiable part of his disability, and the correct approach in the appropriate circumstances was to divide responsibility on a time-exposure basis.

37. The important part of the judgment of Stuart Smith LJ is in paragraph 20 on page 428. He had referred to a number of cases, including reference in a later paragraph to the decision of Mustill J in Thompson v Smiths Shiprepairers (North Shields) Ltd [1984] 1 All ER page 881. Paragraph 20 of Stuart Smith LJ judgment reads as follows:

"I do not accept Mr May's submissions. In my judgment as the passages cited from the three House of Lords' decision show, the onus of proving causation is on the claimant; it does not shift to the defendant. He will be entitled to succeed if he can prove that the defendants' tortious conduct made a material contribution to his disability. But strictly speaking the defendant is liable only to the extent of that contribution. However if the point is never raised or argued by the defendant, the claimant will succeed in full as in Bonnington and McGhee . I agree with Judge Altman that strictly speaking the defendant does not need to plead the others were responsible in part. But at the same time I certainly think it is desirable and preferable that this should be done. Certainly the matter must be raised and dealt with in evidence, otherwise the defendant is at risk that he will be held liable for everything. In reality I do not think that these cases should be determined on onus of proof. The question should be whether at the end of the day and on consideration of all the evidence the claimant has proved that the defendant is responsible for the whole or a quantifiable part of his disability. The question of quantification may be difficult and the court only has to do the best it can using its common sense, as Lord Salmon said in the passage cited. Cases of this sort, where the disease manifests itself many years after the exposure, present great problems, because much of the detail is inevitably lost. I can see that in Borel's case where the defendants were manufacturers as opposed to employers the position may be particularly difficult. But in my view the court must do the best it can to achieve justice, not only to the claimant but to the defendant, and among defendants."

38. The difficulty of quantification, as Mr Spencer pointed out, has been addressed in a number of other cases, notably Turner J's long-running case against British Coal from which we have been provided extracts, and it is certainly the case that if apportionment is necessary the court should not be deterred from doing so because the task is difficult or the result likely to be approximate.

39. In answer to this submission on apportionment Mr McCaul submits that on the facts of the present case there was no question of there being separable or divisible damage. He refers to the evidence of Mr Rushman to the effect that if the heavy lifting in the employment of the defendants had not occurred the claimant probably would not have suffered the catastrophic insult to the conus which did in fact occurred. The defendants, he accepts, did not cause the entire history of the claimant's back disease but the negligent lifting in the employment of the defendants did cause the tear in the annulus which was the cause, and the only cause, of the catastrophic event that occurred in March 1998.

40. Mr McCaul submits that in Thompson Mustill LJ (as he then was) was able to say that a substantial part of the impairment of the plaintiff's hearing took place before the defendants were in breach. Likewise in Holtby , cumulative exposure to asbestos dust lead to a cumulative intensity in the disease. The defendants were only responsible for that part of the damage which they had caused. The damage was linear, and a calculation was capable of being done and was appropriate. In British Coal the claimant's state was likewise the culmination of a progression from actionable and non-actionable causes. But, submits Mr McCaul, in this case there was a single insult causing neurological damage on the judge's finding caused by employment by the defendants and by the employment by the defendants alone. It was an indivisible injury. The defendants had materially contributed to it and were, on orthodox jurisprudence, liable for the whole of the damage. It was not the case that the claimant's conus had been injured before 12 March 1998. There was, admittedly, an antecedent condition, but that condition was not the cause of the damage to the conus which caused the debilitating neurological symptoms. This, he submits, is shown by the evidence of Mr Rushman to which he was referred. Without the negligent acts there would not have been the catastrophe. He submits that paragraph 58 of the judge's judgment refers to the process by which a final debilitating insult to the conus occurred.

41. I have found some difficulty with this issue and with these submissions, not because I am in doubt as to the result, but simply because the judge did not deal with the submission at all. Miss Foster made a clear submission on this subject and I believe that the judge should have dealt with it, although he might have been able to deal with it quite shortly. I have considered whether in those circumstances it would be appropriate and just for this issue, and this issue alone, to be remitted for reconsideration. But I have concluded that it should not for this reason. It is, in my judgment, clear that, although not dealt with by the judge, Mr McCaul's submission is a necessary consequence of the findings which the judge had made on other issues. It was plainly a finding open to him on Mr Rushman's evidence; and essentially it was a finding which followed from the judge's rejection of the defendants' case as to causation. It will be recalled that the defendants' case as to causation was that the debilitating episode from which the claimant suffered and subsequently resulted from spontaneous degenerative disc degeneration. By contrast, it was the claimant's case that this was a disc prolapse caused by heavy lifting in the days and months leading up to the episode itself.

42. The mechanism of injury which Professor Swash and Mr Rushman described and which the judge accepted, was, as I understand it, indeed a single indivisible insult (if that is the right word) which the breach of duty the judge found had caused. It would, or may, of course, have been different had the cause been that for which the defendants' experts contended. I accept the force of Mr McCaul's submission that the defendant/appellant's case on this appeal fails to distinguish between disc degeneration and disc prolapse. The latter was the cause as found by the judge: it was a single indivisible cause and questions of possible apportionment as discussed in Holtby did not arise.

43. For these reasons, in my judgment, this appeal should be dismissed.

44. LORD JUSTICE THORPE: I agree. This appeal should be dismissed for the reasons given by my Lord.

(Appeal dismissed with costs; the claimant's costs to be assessed).