Huynh v Austrim Nylex Limited [2003] SAWCT 76

5 He did not suffer a specific injury at work but has experienced the gradual onset of pain in the left hip over two years.

6 The respondent rejected his claim for compensation on the basis that the disability from which he suffers did not arise out of or in the course of the employment and the employment did not contribute to the condition.

7 The facts of employment are not in dispute to any significant extent. His forklift driving required him to twist his body to see where he was going as he drove his forklift around the factory. His duties required him to get on and off the forklift up to 60 times each shift.

8 There is no dispute that the worker is disabled by the condition in his left hip. In fact the employer has found work for him which is more congenial to his physical condition.

9 A connection with the employment was supported by Dr RJ Odgers, Physician, and by Mr Francis DA Ghan, Orthopaedic Surgeon. Both reported and gave evidence.

10 A report from Dr JA Cook who practices in the field of occupational medicine was in evidence.

11 Dr Mark Awerbuch, Rheumatologist, reported and gave evidence. His opinion denied any employment connection.

2 That avascular necrosis (also known as osteo necrosis) is present in the left femoral head.

3 That latter condition occurs as the result of the disruption of the blood supply to the head of the femur. Its causes are:-

* a developmental condition known as upper femoral epiphysis

* and finally it may be of idiopathic origin ie it is unknown

13 Both of the above doctors agree there is no known connection per se between ankylosing spondylitis and avascular necrosis.

"The pathological process of recurrent trauma to that femoral neck, and if microfractures recurrently occur to that femoral neck one could postulate recurrent damage to the blood vessels of that region and hence the compromising of the blood supply to the femoral head leading to avascular necrosis. Nobody knows the answer to this, it is certainly something that is not supported in the literature but there is certainly no evidence to the contrary ... it is certainly a question that it open, it has no answer either way, it is a potential cause of this aspect of his present problems."

15 In evidence Dr Odgers postulated that the presence of ankylosing spondylitis fused the spinal joints. This process has an effect on the hip joint. The joint becomes stiff. It does not properly fulfil its function as a cushion for shocks and trauma to the trunk. If it does not, the blood supply to the femoral head is restricted by repeated minor trauma such as getting on and off a forklift.

16 He agreed that it is unlikely that the work actually aggravated the condition but the trauma may have led to the development of avascular necrosis in a person potentially predisposed by virtue of having an inflammatory joint disorder or by virtue of his having a fixed and rigid pelvis as a consequence of his fused sacro-iliac joints. He agreed that the most that could be said about repeated minor trauma and its effect, was that it is a potential cause of this aspect of his present problems.

17 Tr 46:-

"Q ... taking into account both the literature, your knowledge of your patient and everything you know about the views of other consultants ... you don't put it any higher than this: that the influence of the employment is an open question. It has no answer, but in your view it's a potential cause of this aspect of the present problem.

18 Dr Ghan agrees that the worker suffers from avascular necrosis but that his work had aggravated the condition. In evidence he expounded thus (tr 49):-

"... the fact that he has a predisposition - that is the disease itself, ankylosing spondylitis, which is not a cause of avascular necrosis, but it causes stiffness of the hip and that itself can, I presume, predispose the hip to abnormal repetitive minor trauma, which can cause this problem."

19 In cross-examination (tr 50), In responding to the proposition that there is nothing in the literature relating ankylosing spondylitis to avascular necrosis it was put to him that if there was such a relationship. He said that:-

"Q ...one would expect to see a lot more cases of avascular necrosis, wouldn't we in people who had ankylosing spondylitis.

A All I can say is that every person is different - every person is different.

Q In your experience have you come across a situation where in the absence of a specific trauma - namely, a fracture - somebody with ankylosing spondylitis has developed an avascular necrosis of the femur - the head of the femur.

A This is the first case. There's always a first."

20 At tr 52 Dr Ghan he said he would not agree with Dr Odgers' view that as a result of the fusing of the spine, the hip has a less cushioning effect and as a consequence the head of the femur has a greater weight- bearing than it otherwise would. This was because the weight is actually transmitted from the lower limbs so he would not expect there would be any greater pressure or weight bearing on the head of the femur as the consequence of having ankylosing spondylitis. At tr 53:-

"... the stiffness from the ankylosing spondylitis has actually set the scene for his condition."

21 Dr Awerbuch said when he first examined the worker he diagnosed both ankylosing spondylitis and avascular necrosis. These conditions appear in less than one per cent of the population. It is very rare to see them occurring together. Both are uncommon.

22 The coincidence of the conditions tempted him to postulate a mechanism to explain the coincidence. After researching the literature and consulting a Sydney colleague who has a particular interest in ankylosing spondylitis he concluded there was no connection.

23 Therefore, for the purposes of this exercise, ankylosing spondylitis is irrelevant.

24 As to avascular necrosis, he had seen only six cases in his whole professional career over 20 years and they were mostly related to cortico steroids which is a known risk factor.

25 He said there was no support in the literature for the proposition that minor trauma has any relationship to the development of avascular necrosis. "There are no published data suggesting trauma of a lesser magnitude than fracture (my emphasis) in any way increases the risk of avascular necrosis. No data exists supporting the proposition of an increased risk with heavy labourers, or military or freefall parachutists, or marathon or ultra-marathon runners".

26 Standard and accepted treatment for suffers from ankylosing spondylitis is to increase exercise (TB 49):-

"Patients who have ankylosing spondylitis are encouraged to remain active and to exercise on a regular basis because it is known that exercise reduces the risk of ankylosis. Despite exercise being a mainstay of therapy in ankylosing spondylitis, I have found no published studies suggesting that patients with ankylosing spondylitis who exercise are at any risk of developing avascular necrosis of the femoral head."

27 Dr Awerbuch saw the video of the workplace. He said the trauma of stepping up and down from a forklift fell far short of the trauma envisaged in the literature.

28 To the extent Dr Rodgers and Mr Ghan's views depended on the worker having a stiff left hip Dr Awerbuch said there is no evidence that was the case.

30 The conditions under discussion are squarely within the field both of his learning and of his expertise. He had obviously researched this matter carefully. He was astute to distinguish the influence of work as a factor that made the condition symptomatic ie exacerbated it - that is to say made it become florid - as distinct from the work aggravating it ie in the sense of contributing to the progress of or worsening the condition.

31 Dr Cook, in his report, recommended that the opinion of a Rheumatologist be sought. Dr Cook also noted the work related contribution "or at least irritation was weak."

32 Furthermore, both Dr Rodgers and Mr Ghan conceded that their postulation of employment related nexus was at best a possibility.

34 Therefore I find the views of Dr Awerbuch persuasive.

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.