Murton v Workcover/Allianz Australia Workers Compensation

1 Genevieve Ann Murton ("the worker") claims compensation from Spotless Services Australia Pty Ltd ("the employer"). She had osteoarthritis of her right hip. She had a total hip replacement on 1 March 2002. She has not worked since late 2001. She was employed as a "domestic" (in its various forms) since 1983 at the Women's and Children's Hospital.

2 She claims that her medical condition of osteoarthritis is a secondary disability and results from the aggravation, acceleration, exacerbation or deterioration of the primary disability in the hip.

3 S 30(2)(b)(i) and (ii) require a causal connection between the employment and the medical condition.

4 The worker was born on 23 June 1951. She was about 50 when she stopped working.

5 The worker commenced with the Women's and Children's Hospital as a domestic in 1983. Her classification changed over the years to discharge cleaner - patient support attendant. The cleaning services were privatised in 1998 and she thereafter became responsible for pushing food trolleys, ward cleaning, orderly and patient transport work. The work involved some pushing beds, replenishing linen cupboards from linen trolleys.

6 She said that at least since 1998 the cleaning trolleys were big and heavy. At times she used an industrial polisher but this does not seem to have been a frequent occurrence at least in later years. P 65 of the Trial Book sets out a comprehensive statement of her duties.

7 She was not challenged on her description of her work.

8 The general practitioner's medical file was in evidence. Historically it records:-

"6/7/83 Right leg sore for 12/12 in upper thigh; on examination sore on hip rotation, flexion and abduction for hip x-ray.

7/7/83 X-ray NAD except early lipping to the upper articular margin.

2/1/97 history of arthritis for 12 years. Six weeks ago tried to get up from bus couldn't put weight on right leg. On examination tender on side of right hip.

X-rays taken on the 2nd of January 1997 found "relatively advanced degenerative joint disease SC at the right hip with some medial migration of the femural head. There was only mild narrowing of the left hip joint space."

9 X-rays taken on 28 of November 2001 are reported as showing:-

"Severe osteoarthritic changes are present in association with the right hip where there is loss of joint space as well as acetabular protrusion (sic). There are also degenerative changes evident in association with the left hip with narrowing of the medial aspects of the hip joint space on the side. No recent bone injury or bone destruction has been identified."

10 Dr Pam Duffield referred the applicant to Lyell McEwin Orthopaedics Department. The Registrar said that Mr Tom Stevenson after examination admitted the worker for a total hip replacement which procedure was carried out on 1 March 2002.

11 The worker's case is that her work accelerated the progress of the condition. The initial x-ray in July 1983 detected early lipping of the upper articular margin.

12 By January 1997 the x-rays detected relatively advanced degeneration. Hence the progress of the condition is objectively demonstrated.

13 Dr Duffied has been the worker's general practitioner since about 1995. It would be fair to summarise Dr Duffield's views as her originally expressed opinion on 29 January 2002:- "I have no doubt that the nature of Ms Murton's work has caused her condition."

14 That view was later expressed on 17 August 2003 as"-

"I'm confident that these duties (pushing beds especially around corners) pushing trolleys and wheelchairs and cleaning such as vacuuming, sweeping and mopping floors have contributed significantly to Ms Murton's osteoarthritis of the hip."

15 Dr Duffield said that she had examined the research literature which was put to Dr Champion in evidence. Dr Duffield concluded that it supported her view that there was a relationship between the heavy work performed by her patient and the disability in her right hip.

"9... heavy duties of any description that increased weight-bearing activities on the lower limb contribute to it."

17 Mr Tom Stevenson orthopaedic surgeon who was the operating surgeon reported and gave evidence. His report of 4 April 2002 to the Union (TB 74) said:-

"As regards the cause of the arthritic hip, this I think in her case is due to protrusial acetabulae i.e. a congenital abnormality of the socket of the hip which made it go prematurely arthritic. Normal day to day work would not have any influence on this. If she did report one single specific injury at the onset of symptoms or at the time of aggravation of the symptoms, then it would be reasonable to attribute some increase in disability to this but I am pretty sure by the X-ray appearances, that the vast majority of her disability is from osteo-arthritis, secondary to a congenital abnormality of her hip and not work caused."

18 In a further letter to the Union on 19 July 2002 (TB 75) Mr Stevenson said:-

"... this lady has a premature arthritic hip, due to an underlying congenital abnormality. I think if she had reported a significant work injury to her hip at the onset of the symptoms, it would be reasonable to claim that her work aggravated or precipitated the onset of the problem. If this is not the case, I would doubt if it would be work related ...".

20 Mr Stevenson had read the "Book of Medical Literature" and said that the contents did not change his opinion.

21 When a description of some of the worker's activity eg using an industrial polisher was put to Mr Stevenson, he did not accept that this could account for the osteoarthritis or an acceleration thereof. These incidents if anything simply made manifest the fact that the hip was arthritic. He said:-

"... I've got to stress that the vast majority of the causation of a hip going arthritic is the pre-existing shape of the joint and that the injury or incident is only a minor factor that may well have first brought the arthritis to her notice. It's difficult to put a figure on it. I would say 97.5 per cent is pre-existing pathology and 2.5 per cent work caused - it is that sort of range. It is certainly not fifty-fifty or ninety-ten in my opinion." (tr 86) (I pause there to observe that this is quite consistent with his written report.)

"... She certainly has a dysplastic (congenital malformation) hip. This is a congenital thing." (tr 88)

22 Mr Stevenson also said that the worker was, "carrying a bit more than average weight that is probably more harmful than using it a bit more".

23 After the determination of 26 February 2002 which relied on Dr Champion's views, and after Dr Stevenson's report of 4 April 2002 Dr Duffield referred her patient to Mr Brian Wallace orthopaedic surgeon for a medico-legal opinion as to the relationship of the work to the arthritic hip.

24 The text of the referral letter was not in the Trial Book nor was it in Dr Duffield's notes.

25 Dr Duffield had by 22 April 2002 been advised by the compensating authority that it had two opinions that the condition was not work related.

26 At that time the worker was still under the care of Lyell McEwin Hopsital's orthopaedic department. Mr Wallace saw the worker on 21 May 2002. In a report (at TB 51) dated 21 May 2002:-

"As for the contribution of work it is clearly not the cause but it is certainly not unreasonable to say that a physically demanding job over a number of years will accelerate the process and probably bring forward the need for hip replacement by perhaps several years. This may not help her in her claim but it is about as strong as I can be about this difficult situation."

27 On 2 June 2002 Mr Wallace wrote to the worker's Union. He effectively agreed with the diagnosis of Mr Stevenson ie osteoarthritis and protrusio acetablae (at TB 62). His report sums up his views:-

"In my opinion although her employment is not the cause of her hip condition it may have accelerated or aggravated the condition."

28 In the meantime ie after the three consultants had examined her, Ms Murton probably at the behest of the Union compiled a five page statement setting out her view of what her duties were. These were sent to Mr Wallace. On 24 July 2002 Mr Wallace replied to the Union saying that:-

"Assuming that the information provided is a true and accurate history of the onset of the symptoms and the nature of Ms Murton's work I consider it reasonable to state that her work has aggravated an accelerated the pathology in her hip."

29 In evidence on 18 August 2002 Mr Wallace said (tr 21):-

"It's my belief, and I think it is supported by literature, that heavy physical activity will accelerate that process over a period of time. ... the duties reflected quite a physically demanding job ... over a long period of time ..."

"In the literature it would not be difficult to provide support for the fact that excessive or high-level activity leads to progression."

31 Mr Wallace did not nominate the literature or references to which he referred.

32 Mr Wallace differed from Mr Stevenson in that he thought that protrusio acetebulae was not the primary explanation for the right hip condition but that condition was secondary to inflammatory destruction. Osteoarthritis was essentially a degenerative condition but rheumatoid arthritis was not. That was outside the field of his expertise. It was in the field of a rheumatologist. In his opinion:-

"it was very difficult in this common problem to ascertain the relationship between occupation and osteoarthritis - but when presented with a job that is portrayed as regular hours of physical work of a moderately heavy nature over a prolonged period of time on the balance of probabilities I think that would accelerate the process just as much as if she said she was running 20 kilometres per day." (tr 28)

"This is a difficult scenario and I'm not saying it's black and white."

1 The condition was such that it would have in any event degenerated to the extent that it did ie was going to happen anyway.

2 His view was limited to the work "accelerating in the sense of bringing forward that which was otherwise inevitable."

3 It's impossible to answer by how much the end result has been brought forward.

4 In the absence of a pathological sample of the synovial lining of the joint ... it was reasonable to conclude that the genesis of the condition is osteoarthritic rather than rheumatoid arthritis.

35 Following the submission of the claim form, the compensating authority arranged a medical examination by Dr Gary Champion Rheumatologist on 25 February 2002. This took place some days prior to Mr Stevenson's operation.

36 Dr Champion had Dr Duffield's report of 29 January 2002 that said inter alia:-

"I have no doubt that the nature of Mr (sic) Murton's work has caused her condition."

37 He did not have any of the material from Lyell McEwin Hospital in general, or Mr Tom Stevenson in particular.

38 Dr Champion diagnosed severe osteoarthritis in the right hip. He said:-

"it was a straightforward case of osteoarthritis of both hips, worse on the right than on the left, and most likely secondary to a form of dysplasia (malformation) of the hips. Her work has not been responsible for a worsening of her condition ..."

39 Dr Champion cited four reasons singularly or in combination as causative factors:-

40 He noted the worker was overweight and he noted the x-ray report of 22 March 1997 showed relatively advanced degeneration at that time.

41 On 19 August 2003 Dr Champion gave evidence. He adhered to his opinion. He explained that the two factors that aggravate the arthritic process is a high impact on the joint (trauma) and isometric strain. In this the hip was unlike the knee. The hip was surrounded by strong muscle and the hip was essentially not a weight bearing joint unlike the knee. (In this he has quite a different view from Dr Duffield.) As to the view that the worker's occupation accelerated the progress of the disease, he flatly disagreed.

42 Dr Champion reiterated in cross-examination that the worker's experience was the natural progress of a disease becoming symptomatic. At that stage of the cross-examination some medical literature, the inspiration for which was apparently an out of court discussion with Mr Wallace from the day before, was put to Dr Champion. I stopped the cross-examination so the literature could be given to Dr Champion to consider before answering questions on it. Mr Durkin fairly agreed.

43 The matter was adjourned until 13 October 2003. Thereafter the documents were sent to Dr Champion. These have found their way into evidence as part of exhibit R1. They are entitled "Book of Medical Literature". Technically they should have been part of the applicant's case but as they were the subject of a 36 page analysis and further report by Dr Champion it was convenient to mark them as a respondent's exhibit.

45 What emerged was that Dr Champion was now prepared to concede that some studies supported the view that there was a statistical higher incidence of hip osteoarthritis in some groups of farm labourers than is found in the general population. Ie there was an occupational link in that group. That group is largely confined to agricultural labourers and persons engaged in heavy to very heavy work. However Dr Champion did not resile from his originally expressed views. He said that the content of such of those articles that were actually of genuine scientific value supported his views.

46 Dr Champion disagreed with Mr Wallace that the arthritic joint suffered from activity and became painful and that such exercise would lead to more pain and disability. Dr Champion said the contrary is true. It was actually embodied in the advice given by the Arthritis Foundation to patients "use it or lose it". He said patients with arthritis should be encouraged to exercise. That is absolutely consistent with the evidence that I heard in Huynh v Austrim Nylex Limited [2003] SAWCT 76 (that case although involving a hip, also involved ankylosing spondylitis and avascular necrosis). But the evidence on the effect and indeed the necessity of exercise was to exactly the same point.

"Joint cartilage deterioration is a dynamic process. This deterioration is like a crack in the wall. It develops. It's deterioration has nothing to do weight bearing. The aetiology of cartilage deterioration is that the body produces proteins and other substances that have an inflammatory effect and they begin to dissolve the cartilage. There is no medical explanation for that fact that osteoarthritis is more pronounced in the right hip than the left. It is however quite common to see that phenomenon."

48 Dr Champion was cross-examined very extensively on the medical literature. He was quite clear that neither the literature, nor his own wide clinical experience, support the view that the worker's actual work had aggravated or accelerated the osteoarthritis in the right hip.

49 The issue was distilled down to whether the work performed by the worker accelerated the arthritic condition in the hip.

50 The issue of credibility did not arise. The worker's five page statement of her duties which came into existence after the operation and after the consultations at which she gave a history to three consultants does not err on the side of understatement. It is tolerably clear that it is much more elaborate than the history she actually gave at the consultations.

51 It is also tolerably clear that on her account, the work before 1998 was not as strenuous or as difficult as the work after 1998. This may well have a real bearing on the significance of the January 1997 x-ray and her condition before then.

52 The general practitioner formed her opinion in January 2001. It was formed without any input from Mr Stevenson or the orthopaedic department of Lyell McEwin Hospital.

53 I cannot understand how she could claim that the medical literature that was tendered in this case support her view. I am not persuaded by her opinion, partly because it is based on the proposition that the literature supported a work contribution to the progression of the disease, and it is partly based on her perception of the work as "very heavy work." The first proposition is simply wrong. The second proposition is questionable. Dr Duffield seems to have been uninfluenced by or even to have carefully considered the opinions of two senior consultants, another factor which does not assist me in accepting her views.

54 The three consultants who gave evidence were models of objectivity and all of them made concessions when it was proper so to do.

55 Two consultants were orthopaedic surgeons, the third was a rheumatologist.

56 There is a fundamental difference in emphasis between the viewpoint of an orthopaedic surgeon and that of a rheumatologist. I accept that an orthopaedic surgeon is well qualified to opine on what the demonstrated pathological condition of the hip actually is, ie is it osteoarthritits; or the anatomical significance of dysplasia of the hip leading to protrusio acetabulae. I accept the view that that field of expertise is of particular value in determining the usefulness or otherwise of surgical intervention, and what surgery ought to be performed, and how it ought to be carried out. In this there is absolutely no difference of opinion between the two orthopaedic surgeons.

57 However when the discussion moves to the actual cause of the disease, its origin, its progress and its non-surgical treatment, I am inclined to the view that the opinion of a well experienced and properly credentialled rheumatologist carries more weight.

58 It is interesting to note that seven of the eight articles in the book of Medical Literature (which is 41 out of 45 pages), were part of research carried out by Rheumatologists or published in Rheumatology journals.

59 On the evidence in this case it seems that by far the greater part of the research that has been performed in this area has been under the general rubric of Rheumatological studies.

60 That being said, I therefore accept generally the opinion of Dr Champion. Where opinions differ from those expressed by him I prefer his opinion.

61 I do so because of his expertise in the particular area under discussion as well as his intimate familiarity with the medical literature.

62 His explanation of the effect of "compressive forces" (at tr 116) is persuasive. His evidence (at tr 99 - 100) on the effect of work on cartilage degradation is quite convincing.

63 I note that Dr Champion arrived at a diagnosis virtually identical to that of Mr Tom Stevenson the operating surgeon, before the operation and without knowing Mr Stevenson's views.

64 Mr Wallace was helpful. However I am not persuaded by his evidence that there is a real relationship between the worker's work and the progress of the disease. He postulates the literature would support his views. However that is not the case. Further, he adopts a view of the work ie that it was "consistently very heavy" that I do not accept. Mr Wallace did not factor into his opinion the x-ray report of 2 January 1997 which disclosed relatively advanced degenerative joint disease of the right hip, other than that "the worker had told him that x-rays were done about five years ago".

65 X-rays were also done in 1983 and the disease had clearly progressed significantly up to 1997 and the significance of that progression was not commented upon.

66 Mr Tom Stevenson is a well known and senior orthopaedic surgeon. He has performed this hip operation since 1966 carrying out between 50 and 100 every year. Ie over 2000 operations. He was the operating surgeon. His views must carry great weight. His evidence was consistent with his reports. Looked at as a whole he ascribed at most, a two and a half per cent contribution from occupational factors. However seen in the context of his evidence and his reports, that really means that whereas he was not prepared to categorically rule out occupational features completely, they were overwhelmed by degenerative and idiopathic characteristics. Nothing that Mr Stevenson said could enable me using the test in WCC v Sheriff SC Judgment S 5831 to come to the view that occupational factors in the employment were significant enough to be able to say that the disability arose from the employment.

67 I have carefully read all of the tendered material. The use to which this material can be put, has been commented upon this year in Reeves (deceased) v WorkCover [2003] SAWCT 91 par 56 and Murphy v SGIC [2003] SAWCT 2. I do not propose to traverse the medical literature in detail.

68 I am of course reading it as a lay person, albeit hopefully somewhat more informed than a tabula rasa.

69 The material is a mixture of genuine scientific research, of reviews of already published studies, and of some editorialising and special pleading.

70 Dr Champion has analysed that material article by article. I have come to much the same conclusions as he did, albeit from a non-medical viewpoint. Some of the articles contradict other articles.

71 Dr Champion also included in his report extracts from the latest edition of a standard text "Rheumatism" by Elsevior 2003 edition.

72 It is said that osteoarthritis is the most common joint disorder in the world and its radiographic prevalence rises with age. Among the most significant causative factors are heredity, obesity, hypermobility, joint shape and trauma.

73 The text suggests that there is a stronger association between obesity and osteoarthritis in women than in men, which itself suggests a metabolic mediation. Congenital dysplasia ie malformation of the joint or its components is significant.

74 Dr Champion commented that the worker was obese. Mr Stevenson mentioned the same thing in passing.

75 All three consultants agree that the joint was dysplastic. The literature and the standard texts go no further than saying that some studies have found the statistical link mentioned earlier in this judgment. Heavy work, when it is actually defined, seems to be of 25 kilograms or more on a frequent or repetitive basis. That of course does not conclude the matter.

76 As a matter of law the worker is entitled to rely on the elevation of a possibility into a probability on all of the evidence E.M.I. (Australia) v Bes (1970) at 2 NSWLR 238 at 242 which of course is subject to the limitations of the concept of possibility as expounded in City County Council v Furner (1991) 7 NSW CCR 210 - C.A..

77 In this case the evidence does not get past a temporal coincidence of work with pain. Just as the incident that produced the medical attention of 2 January 1997 and the x-ray "six weeks ago when she got up to get from the bus couldn't put weight on the right leg." There was a temporal coincidence only.

78 It is clear that the osteoarthritis has been progressing since 1983. Over the next two decades it became worse until it became acute in 2001. That is the classical pattern of the progress of this disease. The activities of work changed over the years and the changing work pattern coincided with the progress of the disease.

79 Hence on the whole of the evidence written, oral and textual I am not satisfied that the worker's work was related in a causal sense to the work she was performing at the Women and Children's Hospital.

80 I am therefore constrained to confirm the determination.

Parties are advised that if a party wishes to appeal against any part of this decision which is appealable pursuant to s 86(1) of the Act such appeal must be filed with the Registrar in accordance with the form titled Notice of Appeal within 14 days of the delivery of this decision and must be served on all parties.