Rehberg and Comcare (Compensation)

Rehberg and Comcare (Compensation) [2019] AATA 413 (14 March 2019)
Division:GENERAL DIVISION
File Number(s): 2018/0495
Re:Gerhard Rehberg
APPLICANT

ComcareAnd
RESPONDENT

Decision
Tribunal:Dr I Alexander, Member
Dr P Fricker, Member

Date:14 March 2019
Place:Sydney

The decision under review is affirmed.
..........................[sgd]..............................................
Dr I Alexander, Member
Catchwords
COMPENSATION – injury – accepted injury ‘acute lumbar strain’– whether applicant is entitled to continued compensation – s 16 and s 19 Safety, Rehabilitation and Compensation Act 1988 (Cth) – decision affirmed
Legislation
Safety, Rehabilitation and Compensation Act 1988 (Cth)
Secondary Materials
Brinjijki W et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. Am J Neuroradiol 2015; 36: 811- 816
REASONS FOR DECISION
Dr I Alexander, Member
Dr P Fricker, Member
14 March 2017
Background

In 1979, Mr Rehberg, who is now 55 years old, started work as a sheet metal worker with the Australian Defence Industries (ADI). His employment with ADI continued until October 2005 when he was made redundant.
On 1 November 1991, while at work, Mr Rehberg experienced “a pulling and burning sensation” in his lower back[1] but did not report the incident to his employer until 8 November 1991.
[1] A1-Mr Rehberg’s written statement paragraph 5.
Mr Rehberg was off work until 9 December 1991 when he returned to work with selected duties- (clerical work) [2]
[2] Section 37 Document’s [5].
In early 1992 he tried to do some light work in the sheet metal shop, however, when his pain increased, he returned to clerical work and was subsequently permanently redeployed into a clerical position.[3]
[3] Mr Rehberg’s written statement paragraph 7.
On the 21 November 1991 Mr Rehberg lodged a claim for workers’ compensation in respect of an “injury” described as “lumbar back strain”.
Following a consultation with a surgeon, Dr A Middleton, a plain x-ray and CT scan of the lumbar spine was performed on 12 February 1992. The plain x-ray revealed a “considerably narrowed” L5/S1 intervertebral disc and the CT scan was reported as showing “a large posterior disc protrusion” at the L5-S1 level.
In a determination dated 28 July 1992, Comcare ceased Mr Rehberg’s incapacity payments. In a reconsideration decision dated 4 January 1993, Comcare accepted continuing liability in respect of the “acute lumbar strain” suffered on 1 November 1992.
In a determination dated 26 October 2017 a Comcare delegate decided that Comcare had no “present liability” for the condition “acute lumbar strain” pursuant to sections 16 or 19 of the Safety, Rehabilitation and Compensation Act 1988 (SRC Act) .
In a reviewable decision dated 15 January 2018, the Review Officer affirmed the Determination dated 26 October 2017 which “declined present liability for medical expenses and incapacity payments under sections 16 and 19 of the SRC Act.”
In these proceedings Mr Rehberg seeks review of the reviewable decision.
At the hearing both parties were represented by counsel. Mr Rehberg wished to rely only on his written statement and not give oral evidence. The parties agreed that he was not required for cross examination.
STATUTORY PROVISIONS
Section 14 of the SRC Act provides that Comcare is liable to pay compensation in respect of an injury suffered by an employee if the injury results in death, incapacity for work, or impairment.
As Mr Rehberg’s injury pre-dates the 2007 amendment of the Act, the definition of “injury” is set out in section 4(1) of the Act as it was prior to that time:
“Injury” is defined in section 4(1) to mean:
a disease suffered by an employee; or
an injury (other than a disease) suffered by an employee, that is a physical or mental injury arising out of, or in the course of, the employee’s employment; or
an aggravation of a physical or mental injury (other than a disease) suffered by an employee (whether or not that injury arose out of, or in the course of, the employee’s employment), that is an aggravation that arose out of, or in the course of, that employment;
“disease” is defined in section 4(1) to mean:
(a) an ailment suffered by an employee; or
(b) an aggravation of any such an ailment;
being an ailment or an aggravation that was contributed to material degree by the employees employment or a licensed corporation
“ailment” is defined in s 4(1) :
ailment means any physical or mental ailment, disorder, defect or morbid condition (whether of sudden onset or gradual development).
Section 16 of the SRC Act provided, inter alia, that “where an employee suffers an injury, Comcare is liable to pay, in respect of the cost of medical treatment obtained in relation to the injury………”
Section 19 of the SRC Act provided, inter alia, that “This section applies to an employee who is incapacitated for work as a result of an injury…….”
ISSUES
There is no dispute that in November 1991 Mr Rehberg suffered a compensable injury for the purposes of section 14 of the SRC Act, in that he experienced lower back pain while at work which resulted in a period of incapacity for work.
It is agreed that, at that time, Mr Rehberg had a pre-existing degenerative lumbar spine condition spine involving the L5/S1 intervertebral disc.
It is also agreed that the “injury” suffered by Mr Rehberg was an “aggravation” of his pre-existing lumbar spine condition.
The Respondent contends, that the November 1991 incident was a “temporary aggravation” of Mr Rehberg’s pre-existing condition and that, as at 26 October 2017, he no longer suffered the effects of the compensable condition and, therefore, was no longer entitled to compensation pursuant to sections 16 and 19 of the SRC Act.
The Respondent also contends that his ongoing and current symptoms are consistent with the natural history of his pre-existing degenerative condition.
Mr Rehberg contends that in November 1991 he suffered a “permanent aggravation” of his L5/S1 intervertebral disc condition and this aggravation “materially contributes” to his ongoing and current symptoms and, therefore, is still entitled to compensation pursuant to section 16 and 19 of the SRC Act.
Therefore, the resolution of this matter requires a consideration as to the nature of the compensable “injury” suffered by Mr Rehberg in 1991 and whether in October 2017 he continued to suffer any effects of that injury.
EVIDENCE
Mr Rehberg’s written statement dated 20 December 2018
Relevant extracts from Mr Rehberg’s statement are as follows:
When I was about 15 years old I left school and started work with the Australian Defence Industries in about 1979 as a sheet metal worker.
I have suffered a few injuries to my lower back prior to my injury the subject of this dispute, all of which I have considered to be minor. Specifically:
a.    In about mid- 1990 I was installing sleeping beds during my work and tripped over a lug while I was carrying a bunk and hurt my back. I don’t recall needing any time off work for this incident but I believe I required some pain medication for about a month.
b.    In early 1991, I tripped on a step at home and strained my back……My lawyers have advised me that a report from 1992 from Dr Middleton suggests I was off work for this incident for about four or five weeks. I can’t remember how much time off work I had but this sounds about right.
……..I do not recall any other injury to my lower back other than what I have described above.
On 1 November 1991, I was riveting two large pieces of ventilation together and was in the process of rolling it over onto the work bench when I felt a pulling and burning sensation in my lower back. I estimate that the two pieces of ventilation weighed about 60 kilograms.
Over the weekend the pain continued and by the following week I felt barely able to work. As the pain was not decreasing I reported the injury to the medical centre at work on 8 November 1991. I also went to see my family doctor who recommended I take a couple of weeks off work and obtain physiotherapy which I did ……but it did not help
When I returned to work, I was placed on light duties. As my back had not recovered, I was not allowed to do my usual sheet metal work. In early 1992 I was tried to do some light duties in the sheet metal shop but my pain increased so I was put back into clerical work. Eventually I was permanently redeployed into a clerical position.
Even during my time in a clerical role, my back would continue to hurt…….I feel that the pain in my back is pretty much the same as it was since I sustained the injury in November 1991, that is after the initial severe pain subsided ……Currently, I take Panadol and Neurofen when needed for my back pain
In 2005, I was retrenched and since that time I have been unemployed, My restrictions are still the same as they were then …….the constant pain that I suffer from on a daily basis only arose from the incident on 1 November 1991. Unfortunately, there part of my life which has not been effected [sic] because of this incident
MEDICAL EVIDENCE
Dr Chua, Mr Rehberg’s family GP.
Relevant extracts from Dr Chua’s clinical practice notes are as follows:
·7/8/89 – c/o back pain was doing some axing over weekend
·5/9/90 – backache – since lifting a heavy object (Bunk) on Monday no radiation of pain…muscular pain Voltaren 50mg mc until Monday R Monday ….4/9→10/10/90
·15/4/91   – illegible
·17/4/91- still having low back pain (L) side no radiation some ↓ in movements P Xray lumbar spine
·18/4/91- Xray NAD no significant abnormality …..MC 15/4/91 – 22/4/91
·22/4/91- Still having back pain refer physio
·27/4/91 – s back still painful when moving around mc 28/4/91- 3/5/91
·7/5/91- today going to work back pain started up again   mc 7/5/91-15/5/91
·15/5/91 – back has improved cleared for light work
·8/11/91 – (1/11/91) …has been to work this week but back pain is getting worse   O lumbar strain   …..mc 8/11/91-15/11/91
·11/11/91 – back pain ++ stiffness + unable to walk properly
·15/11/91 – not much change from last…still having pain/stiffness   lumbar region mc →21/11/91
·21/11/91- feels a bit better not so stiff
·29/11/91- improved still having pain and stiffness
·6/12/91 improved still having stiffness light duties 9/12/9127/12/91
·4/1/92 – walking around freely still having light back pain
·20/2/92- CT scan disc protrusion L5-S1
·21/5/92- ISQ back pain last 2 days
·27/5/92 – flu …mc 27/5/92→29/5/92
·1/6/92 – c/o back pain ++ since last visit there is radiation of pain to the back of thighs fronted up at work today but was unable to carry on mc 1/6/92→/8/6/92
·9/6/92 improved back to work
From 1993 to 1995 Dr Chua frequently recorded that Mr Rehberg continued to complain of lower back pain.
In 1996 the complaints were less frequent and recorded as “back pain on and off”. There is nothing legible in the notes to explain why, in June 1996, Mr Rehberg was referred to see Dr Giblin who arranged new imaging of the lumbar spine. The Tribunal presumes it was at the request of Comcare.
From 1997 to 2007 there were occasional complaints recorded as “back pain on and off, back pain still present, back pain ISQ, back restricting activity occasion”.
From 2008 to 2011 there was no mention of back pain.
In 2012 there were 3 visits noted and on one visit, 16 October 2012, Dr Chua recorded “no change in the condition of the lumbar spine”.
Between 2015 and 2017 the only mention of back pain was recorded on 21 October 2016 as “ISQ his low back pain’.
The Tribunal notes at this time, that Dr Chua’s clinical notes can best be described as superficial and incomplete. Between 1992 and 2017 Dr Chua has provided no convincing clinical assessment of Mr Rehberg’s condition. There is no description of Mr Rehberg’s actual symptoms and no indication as to the severity or frequency of the symptoms.
In our view Dr Chua’s practice notes do not appear to support Mr Rehberg’s contention that he continues to suffer significant symptoms which can be attributed solely to his “injury” in November 1991.
In a brief note dated 20 September 2017 Dr Chua stated, inter alia, the following:
Mr Rehberg has been on workers compensation since the early nineties. He had a prolapse lumbar disc and develop chronic low back pain. [sic] He last saw Dr Giblin in 1992 and I am enclosing this report. Currently he undertakes light work around his house and takes analgesics when required. I agree with Dr Harbison that he is fit to undertake alternative duties but not to return to work as a sheet metal worker. He has been fit for these duties for many years but has not had any formal rehabilitation or retraining.
Imaging
An x-ray of the lumbar spine performed on 17 April 1991 is reported to show no obvious abnormality.
An x-ray of the lumbar spine performed on the 12 February 1992 is reported as showing that “the lumbosacral disc space is considerably narrowed”
A CT scan performed on 12 February is reported as showing “a large posterior disc protrusion” at L5/S1.
An x-ray of the lumbosacral spine performed on 3 June 1996 is reported as showing “marked narrowing of the L5/S1 disc.”
A CT of the lumbar spine performed 3 June 1996 is reported as showing a “left lateral and postero-lateral disc protrusion” at the L5/S1 level.
An x-ray of the thoracic and lumbar spines performed on 15 June 2018 is reported as showing inter alia the following:
There are osteoporotic compression fractures of vertebral endplates of some thoracic vertebrae with 20% reduction in height and increased kyphosis…..There is narrowing of the L5/S1 disc space, consistent with degeneration.
Dr A. Middleton, Surgeon[4]
[4] The is no indication in the document that Dr Middleton was an orthopaedic surgeon.
In a report dated 19 February 1992 Dr A. Middleton stated inter alia the following:
Mr Rehberg has had episodes of low back pain over the past 18 months. His most recent episode followed work on November 1,1991…..On the Friday in question he was joining the sections and this involved riveting the sections and rolling the sections over on the bench. His lower back started to give him trouble on that day. He kept on working and completed the riveting. He went home on that day, a Friday, and returned to work on the Monday. Gradually through the week his back became more painful …by Friday he found he could not cope and went to see the nurse at work and reported his problem
X-rays Films dated April 17, 1991 were of lumbo-sacral and show no obvious abnormality. There was no accompanying report. [emphasis added]
Mr Rehberg has had three episodes of low back pain in the past 18 months…. There has been little in the way of investigations of this pain and I have arranged x-ray studies of the lumbo-sacral spine and CT scan of the lower lumbar spine.
Please note that at L5/S1 there is demonstrated a large posterior disc protrusion. In the plain films of the lumbar spine the lumbo-sacral disc space is noted to be considerably narrowed.
Mr Rehberg has been employed by ADI since the age of 15 years as a sheet metal worker. It is reasonable to assume that the disc protrusion that he now suffers is related to the work undertaken during that employment. His symptoms are consistent with a prolapse of the disc a the L5/S1 level
It is recommended that he should consult an orthopaedic surgeon…..I would suggest that he be referred to Dr John Cummine .
Dr E. Graham, orthopaedic surgeon
In a letter dated 25 March Dr Graham noted that Mr Rehberg injured his back at work on 1 November 1991 and stated that at the present time he “has got a low back pain without any leg pain. He did have leg pain a few weeks ago but now has just got a backache.”
Dr Graham stated that “there is no doubt to my mind that the incident 1^st November is responsible for Mr Rehberg ‘s low back pain and sciatica”.
Dr Graham recommended reduction of “the volume of the bulging L5S1 disc with the aid of the enzyme Chymodiactin”.[5]
[5] It is noted that Mr Rehberg preferred not to undertake this treatment.
Dr Cummine, orthopaedic surgeon
In a letter dated 13 May 1992 Dr Cummine noted Mr Rehberg’s past episodes of back pain and stated that at the time of review “his major complaint was pain in the low back which is constant and made worse if he sits for a long time or stands”.
Dr Cummine examined the X-rays provided by Mr Rehberg and stated that the CT scan of 12/2/92 “shows some degenerate disc disease which is also present on the plain rays of 17/4/91.”
Dr Cummine stated that Mr Rehberg located his pain “pretty well entirely in the low back, so I think it is unlikely that this is a disc prolapse requiring evacuation” and concluded that Mr Rehberg “has got degenerative disease as he approaches early middle age, and the plain rays and the CT combined suggest that it is only the lumbosacral disc that’s involved. I think that the appearances are more those of degenerate disc disease rather than frank prolapse.”
In a letter dated 18 June 1992, in response to questions from Comcare with respect to Mr Rehberg’s “degenerative condition” and his employment Dr Cummine stated as follows:
1. I think Mr Rehberg’s current condition relates to his employment only so far as the work has acted either as a precipitating or temporary aggravating factor for his underlying degenerative disc disease.
2. In regard to the duration of aggravation, I would think a period of between three and six months would be a reasonable estimate, exercising the benefits of uncertainty in favour of the patient.
Dr P. Giblin, orthopaedic surgeon
A In a relatively brief letter dated 5 August 1992 Dr Giblin stated, inter alia, as follows:
Many thanks for referring this 29 year old sheet metal worker with low back pain radiating towards the buttocks and posterior thighs…..Just for my records, he hurt his back at work lifting a large piece of ventilation equipment in September 1990. [sic]
His cat scan scan shows a 5/1 disc protrusion in the midline consistent with his clinical diagnosis of discogenic mechanical back pain [emphasis added].
There was no reference to the plain x-rays that had been taken in April 1991 and February 1992
In a letter date 3 June 1996 Dr Giblin states, inter alia, the following:
Many thanks for referring this 35 year old gentleman with a long history of episodic mechanical low back pain and some secondary, intermittent left proximal thigh pain
Just for my records, he first hurt his back in 1988 at work[6] when he was carrying, twisting, and tripped. He had 6 weeks off. He then had a fall at home in 1990[7] and had four weeks of with similar symptoms …..In 1991 he hurt his back when he was lifting and he had sic weeks off work[8]….His old CT scan shows a left sided disc bulge at 5/1……I have asked him to have a repeat CT scan….[emphasis added]
[6] There is no evidence of any injury at work in 1988
[7] This fall was in early 1991 - A1 para.3
[8] A1-Mr Rehberg had two episodes in 1991
In a brief letter dated 7 June 1996 Dr Giblin stated that the “repeat CT scan does show some progressive changes at L5/S1 compared to the x-rays 4 years ago. In fact, the left sided disc bulge has become somewhat calcified and there is some foraminal stenosis at that level. There was no reference to the plain x-ray that was also taken.
In a letter dated 22 September 2003 Dr Giblin stated, inter alia, the following:
My records indicate that I saw this gentleman when he was 35 Years old on 3rd June 1996
He said that he had back pain since about September 1990 and that he had injured it again in 1991 and November 1991……….When I saw him on 22^nd September 2003, he reported that he was doing clerical duties but he still experienced symptoms in his back and occasionally the left leg. The symptoms are usually described as sharp stabbing pains and generally related to physical activities……Although he is doing a sedentary job, he says his back pain is still present in terms of exacerbations and remissions….at the present time he takes no prescriptive medication. There has been no recent substantial injury history, nor have any new x-rays been taken.
It is my view that his symptoms will persist indefinitely, in terms of exacerbations and remissions, and there will be a gradual deterioration as he gets older. I assess his current condition as being mainly related to the injury sustained by him in November 1991.
I have read a copy of the report of Dr Neil W McGill dated 24^th July 2003 and I am in agreement with his opinions concerning the inherited constitutional disorder of lumbar disc disease.
Nonetheless, it would be my opinion that his current disability is related to material damage from the injury of November 1991, and that this material damage has caused an acceleration of the underlying constitutional inherited condition, producing, for the main part, his symptom complex formation and resulted disability. [emphasis added]

In a report dated 10 November 2017 Dr Giblin repeated much of the preliminary information that was reported in his earlier report in 2003.
However, he did confirm that in the intervening 14 years there had been no “new frank injuries” and no new radiological investigations. Also, that currently Mr Rehberg is not having “any structured treatment” but takes Panadol and Nurofen, on an “over the counter basis” and sees his GP occasionally.
Dr Giblin concluded that Mr Rehberg “has the ongoing diagnosis of a soft tissue injury to his lower back, related to his injury of 1991”.
Dr Giblin goes on to state the following:
There is a reasonable acknowledgement that there were pre-existing degenerative changes in the lumbar spine at least consequent upon the symptoms occurring in 1990. Following the injury in 1991, the nature and conditions of his work environment were such that there was ongoing recurrent material aggravation of his symptoms causing him to seek clerical duties.
It is my opinion that his current symptoms and physical restrictions are related both to pre-existing degenerative changes and the effects of his ongoing injury”. These effects are material in nature, permanent in character, and represent a source of permanent symptomatology and physical restrictions as noted.
Dr Giblin attended the hearing by telephone. In his evidence-in-chief he confirmed his opinion that “the injury that Mr Rehberg suffered on 1 November 1991 in the course of his employment, aggravated a pre-existing degenerative condition is his lumbar spine” and that he “continues to suffer from both the degenerative condition and the work-related aggravation”.
He also confirmed that the opinion he expressed in his 2017 report is to the effect the Mr Rehberg continues to suffer from both the degenerative condition and the work-related aggravation.
Dr Giblin explained as follows:
…….I’m firmly of the belief that he has a genetic vulnerability or predisposition to degeneration and injuries to the soft tissues of his lumbar spine. The first two or three injuries that he had in the 1990’s were minor and he made a good recovery, as you would expect for somebody who is only 29 or 30. But every injury, to some extent or another, is cumulative, given that the healing process always leaves some degree of scar tissue, which is not as good as the normal, uninjured collagen tissue. So, it is my feeling that the indexed injury of 1991, was sufficient to tip him over the edge, so that he could no longer recover and that the injury that was left there was an ongoing deterioration.
In cross examination, Dr Giblin, when asked to explain his description of the 1991 injury as “soft tissue injury”, he stated that “The soft tissue injury is a generic term from a mechanical standpoint and from an anatomical description, there would be a lesion or a tearing somewhere within the soft tissue of the nucleus and the annulus of the disc proper” and expressed the opinion that this is what happened in 1991. He also confirmed that he believed that an intervertebral disc is usually considered to be “soft tissue”.[9]
[9] This belief is not consistent with the evidence of Drs Mcgill, Bentivoglio and Harbison.
Dr Giblin agreed, that he had previously given an opinion that degenerative changes in the lumbar spine had begun before the 1991 incident which he now described it as a “pre-existing vulnerability”, but was unable to recall whether he had seen evidence of degeneration before November 1991.
Dr Giblin agreed that degenerative changes of the spine can be identified by a plain X-ray and that “a subtle loss of disc height” is consistent with degeneration.
When asked whether the radiologist’s report, on the plain lumbar spine X-ray performed on the 17 April 1991, described a degenerating disc Dr Giblin agreed that there was evidence of degeneration at that time.
When asked whether one would see changes on an x-ray after an incident, such as occurred in November 1991, which he had described as it, “It pushed him over the edge so he could no longer recover” Dr Giblin said “Yes, but it would take a good few years.”
When Dr Giblin was asked why one of the incidents prior to November 1991 can’t be implicated as the triggering event he said, “Well, they can, but you have – I had to rely on a history that there was recovery and back to normal duties in an unrestricted fashion. That was what I had to rely on, but yes, your point is accurate.”
Dr Giblin agreed that symptoms, in a degenerative spine, can go in to remission and can last “for 6, 12, 18 months, if you’re lucky” and conceded that Mr Rehberg had experienced some remissions.
When asked whether there was any “direct evidence that November 1991 actually was the “tipping point of the degeneration” Dr Giblin said, “only the history.”
When asked whether an opinion expressed by Dr McGill in a recent report, was unreasonable, Dr Giblin stated that “it’s not unreasonable for a rheumatologist” and explained his answer by saying “He hasn’t got any experience in treating back pain.”
Dr Giblin was asked by the Tribunal to explain his repeated reference to the CT scans as showing a “disc bulge” rather than a “disc protrusion”. He responded inter alia as follows:
That’s a matter of nomenclature only. I’d have to look at the X-rays myself to be satisfied that I agreed or disagreed with the written report. ……… There is such great variability in reporting nomenclature, that it’s just not reliable.
Dr Giblin indicated that his opinion is that Mr Rehberg’s currents symptoms are causally related to the disc injury suffered in 1991 because “his symptoms are basically the same”
Dr Chan, surgeon [10]
[10] The is no indication in document whether Dr Chan was an orthopaedic surgeon.
In a report dated 18 December 1992 after noting the three past episodes of pain described by Mr Rehberg and the degenerative changes in the x-rays and CT scan Dr Chan concluded as follows;
Mr Rehberg has backache and investigations show he had a lumbosacral disc protrusion. It is possible that this is the cause of his backache. It can only be confirmed if surgical intervention relieves him of his problem. we can only presume the relationship between the two
Whether the disc protrusion had been caused by any of the three instances recounted to me I cannot say for sure. However, it is likely that the 13 years of work had done on ships may have aggravated a pre-existing degenerative condition ……In the late 20s only one quarter of the population will have disc degeneration …..
DR R.W.D. Middleton, surgeon[11]
[11] It is not clear whether Dr Middleton is a general or orthopaedic surgeon
In a report dated 6 March 1997 Dr Middleton stated that in 1989, while at work, Mr Rehberg “felt his back go” and was off work for 2 to 3 weeks. In 1990 he developed backache at home and was off work for 3 to 4 weeks. On 1 November 1991 he felt “a tearing sensation” in his back but initially continued go to work. One week later the pain became worse and he was off work for 3 weeks. [12]
[12] This history is not consistent with Mr Rehberg’s written statement
Dr Middleton reviewed the various X-ray and CT scan reports and concluded that “there has been significant radiographic progression of changes at L5/S1 over the period observed.[13]
[13] It is not clear from the report whether Dr Middleton relied on the radiologist’s reports alone or actually viewed the x-rays.
Dr Middleton expressed the opinion that Mr Rehberg “has the residuum of a left L5/S1 prolapse. Because of the increment in disc narrowing between 17/4/91 and 3/6/96 it is likely that the last incident that he sustained in November 1991 is the factor which is causing his present disability.”
Dr Middleton goes on to state “I think his present disability is probably related to the injury at work sustained in November 1991’ and that “his employment was the cause of his present disability.
The Tribunal notes at this point that, in his report Dr Middleton does not provide a meaningful assessment or description of Mr Rehberg’s “present disability”
Dr McGill, consultant rheumatologist
In a report dated 24 July 2003 Dr McGill records a history of the major complaint for the period of 1990 to 1992 which essentially accords with Mr Rehberg’s written statement and the history recorded by Dr A, Middleton in his report of 19 February 1992.
Dr McGill goes on state inter alia as follows:
His low back pain has improved but he has continued to experience fluctuating discomfort in the low back ever since. In the early period the pain radiated to the back of his left thigh. Radiation to the left lower limb still occurs occasionally although is much less troublesome than it was previously. He has not required any further time from work because of his lower back. [emphasis added]
In the last few years has been aware of discomfort in the right shoulder region…..I asked him to recap on his current symptoms, commencing with the most troublesome. He indicated that his right shoulder is the most troublesome area……….He explained that he is able to keep his low back symptoms “pretty good” by getting up every 30 minutes and having a short walk around to loosen up and by avoiding prolonged period of sitting…..he has not required any medication for his low back for many years……He does not currently have any symptoms of cervical or lumbar nerve root irritation [emphasis added]
He brought with him plain x-rays of the limbo-sacral spine performed 17 April 1991 with repeat plain x-rays on 12 February 1992. I thought that the two sets of x-rays were the same and they both demonstrated moderate narrowing of the L5/S1 disc space. [emphasis added]
A repeat CT scan of the lumbar spine performed on 3 June 1996 again demonstrated the left sided disc protrusion at L5/S1 with osteophyte formation. Plain x-rays of the low back and pelvis on 3 June 1996 demonstrated sclerosis in the L5/S1 facet joint, narrowing at the L5/ S1disc space ……
He has degenerative disc disease predominantly at L5/S1. In light of the fact that his plain x-rays in April 1991 showed chronic degenerative change at the L5/S1 level (changes which take years to develop) I think he had pre-existing constitutional lumbar disc disease prior to the incidents at work and at home that he described as aggravating factors. Both of the work related episodes were relatively minor. I think that both work related episodes influenced the severity of the symptoms in the period following those episodes. On the basis of probabilities, I think the work related aggravations had probably ceased within 3 months of each work related episode. I think it is probable that the current state of his low back would have been the same regardless of the work episodes which occurred in 1990 and 1991. I cannot exclude the possibility that the 1991 episode may have provided a small permanent aggravation. As explained above, on the balance of probabilities, I think his work duties did materially contribute to the severity of symptoms in 1990 and 1991 and in early 1992 but probably do not continue to materially contribute to his current condition.
Lumbar disc disease has been demonstrated to be a strongly inherited constitutional disorder. I enclose a copy of the review article by Videman & Battie which discusses the literature available at that time.[14] There have further studies since then confirming the importance of inheritance.
His low back condition is permanent even though I think it is probable that the work related component was temporary.
[14] A copy of this review article was not provided to the Tribunal
In a report dated 20 June 2018 Dr McGill stated, inter alia, the following:
15 June 2018. X-rays of the thoracolumbar spine demonstrated multiple endplate irregularity in the thoracic region. The radiologist interpreted the findings as compression fractures although I think Schmorl’s nodes were more likely. He has not had thoracic pain and the thoracic vertebral abnormalities are relevant to his low back pain.
In the lumbar spine there was narrowing of the L5/S1 space. I was able to compare the images directly with the x-rays performed 12 February 1992. The appearances at L5/S1and elsewhere in the lumbar spine, were similar despite the more than 26 year interval between the imaging. [emphasis added]
This 55 year old man has experienced fluctuating back pain since 1990.In the early period he had three minor incidents, each of which caused him to experience symptoms at the time but none of which is likely to have altered the structure of his back. The first episode occurred in 1990…..The initial imaging occurred on 17 April 1991 at which time he had chronic degenerative changes evident with moderate narrowing of the L5/S1 disc space. On 12 February 1992, CT scan demonstrated a large posterior L5/S1 disc protrusion. His recent plain x-ray again demonstrated narrowing at the L5/S1 level and I was able to compare the recent images with those obtained in 1992 and the appearances were similar. [emphasis added]
He has degenerative lumbar disc disease. It is extremely common in the general community and by the age of 55 years is present in most people. The study by Brinjikji et al (attached)[15] was a systematic review of studies of CT and MR imaging of asymptomatic individuals. The prevalence of degenerative findings in asymptomatic people at the age of 50 years was disc generation 80%, disc height loss 56%, disc bulge 60% and disc protrusion 36%. At the age of 60 years, the prevalence was disc degeneration 88%, disc height loss 67%, disc bulge 69% and disc protrusion 38%. When he was first found to have disc protrusion at L5/S1, he was about 29 years of age. The prevalence estimates for asymptomatic 30 year old people was degeneration 52%, disc height loss34%, disc bulge 40%, disc protrusion 31%.
Hereditary factors have been proven to be important in the development of degenerative disc disease, including in the lumbar spine
I think this condition was temporarily aggravated by the work he performed including his work and injury in 1990 and his work duties (without specific injury) in 1991. I think the duration of the work aggravation was less than 3 months on each occasion (based on the nature of the work activity/injury, the presence of chronic degenerative change evident on imaging studies in April 1991, and the frequency of imaging findings found on studies in the general population even in the absence of symptoms).
I think the current state of his low back would have been the same regardless of his work with ADI.
[15] Brinjikji et al AJNR J Neuroradiol 36:811-16 April 2015
In response to issues raised by Dr Bentivoglio Dr McGill provided a supplementary report dated 25 August 2018 in which he stated inter alia as follows:
Dr Bentivoglio recorded that he “would have to assume that disc prolapse occurred as a result of the specific incident on 1 November 1991”, referring to the central and left sided disc protrusion at L5/S1 detected at the time of CT scan in February 1992.
Although Dr Bentivoglio in the radiological investigations section noted that he saw x-rays of the lumbar spine performed in April 1991 which showed a reduction in L5/S1 disc space, he made no further mention of the radiological finding.[16] Had the event in November 1991 caused a significant change in the structure of the L5/S1 disc one would expect there to have been a change in the disc space narrowing at L5/S1. Dr Bentivoglio in his report……..considered that the reduction in L5/S1 disc space seen on the plain x-rays was accounted for by the disc protrusion detected at the time of the CT scan in February 1992. I agree that the disc space reduction on x-ray and the disc protrusion seen on CT both reflected degenerative change in the L5/S1 disc... The lack of change in the disc space height between April 1991 and February 1992, does not support the suggestion that the episode of low back pain on 1 November 1991 was associated with a significant change in the structure of his L5/S1 disc or his back in general…….I confirm the conclusion I provided in my report of 20 June 2018. I disagree with the conclusion reached by Dr Bentivoglio that “all of Mr Rehnerg’s disability relates to the specific incident on 1 November 1991” [emphasis added.]
[16] In his report of 23 August 2018 Dr Bentivoglio stated that he had not viewed the 1991 xray but had noted the findings of the radiologist’s report
In his evidence-in-chief, at the hearing, Dr McGill explained that rheumatologists have a major role in the assessment and treatment of low back pain. He said that the “vast majority of low back pain is a non-surgical management problem and rheumatologists are a substantial group to whom low back pain is referred”. He added that rheumatologists have “have played a major role in terms of the research that goes into the approach to low back pain and that’s promulgated through our research meeting”.
Dr McGill confirmed his opinion that that the plain x-ray of April 1991 showed chronic degenerative change at the L5/S1 level and stated that this degenerative process “began well before 1991”. He explained that degenerative disc disease comes on gradually, is predominantly “an inherited disorder”, is not predominantly related to injury and gets increasingly frequent with age.
He added that, if someone has a major injury to a disc, then that can cause a permanent change in that disc, which might change the course of that normal degeneration but minor events along the way usually do not make a difference.
Dr McGill explained that, in order to judge whether a difference has occurred one can look to see “whether the degree of degeneration of the disc has changed in a manner that’s outside of what one would expect with the natural history”.
Dr McGill explained what he meant by a major disc injury as follows:
The circumstances can be quite varied. So people will sometimes suffer what I would call a major disc injury with only relatively minor trauma……if you took a person who previously had a normal disc space height and there was no reason to think that they had degenerative change that was more than minor, in other words not detectable by plain X-ray, and had an event and developed sciatica or was shown to have a disc protrusion at that time and that, you know, their sciatica might have taken six months to settle down, and that then they had a follow up X-ray or had an X-ray then performed at that time showing a normal disc height and one done say three years later showing that the disc height had then diminished, then I would accept and I would conclude that the injury that they suffered at the beginning of that three year period had had an adverse effect on the disc and had contributed substantially to that loss of disc height….……if it’s a substantial one you might see a change within a year but it takes months for it to happen.
Dr McGill confirmed that he had looked at the “actual films” of the plain x-rays taken in 1991, 1992 and 2018 and concluded that the narrowing of the disc space shown on those films was similar. He added that he looks at a lot of x-rays himself and does not simply rely on radiologist reports. He explained that there was “obvious degenerative change” in the April 1991 x-ray and the lack of change in the 1992 x-ray provided “some confirmation of my views at that stage” and the fact that x-rays taken 26 years ago, that he got to review in 2018 “didn’t show a change” was further confirmation.
Dr McGill was asked to comment on other evidence that “In a degenerative spine you can have multiple periods of symptoms arising from incidents but then one incident may occur that is sufficient to push someone over the edge from which they can no longer recover” and replied as follows:
If it’s a major episode, yes, but the concept of a series of minor incidents and that one pushes someone over the edge, no, I don’t think that that’s a valid representation of the pathology and the natural history. I mean the natural history of degenerative disc disease regardless of injury is to cause flares of pain that settle. And in some of those people eventually the flares won’t settle and they go on to develop chronic symptoms. The suggestion that an event or an injury causes that, it has to be a substantial event, a substantial injury to affect the natural history. I mean someone ending up with chronic symptoms doesn’t equal an event must have caused that to happen because it’s part of the natural history.

Dr McGill was asked by the Tribunal to comment on the reasoning that, as the earlier episodes of pain appeared to have settled completely and symptoms had continued after the November 1991 episode, this episode was a sentinel event which accelerated the pathological process. He stated that he did not agree with this reasoning and explained as follows:
We have proof that he has degenerative change …..we’ve had proof he’s had episodes of pain. The fact that someone goes on to a state of continuing to report symptoms doesn’t equal that a minor event at the beginning of the period caused that continuation of symptoms….symptoms arising from degenerative back problems spine problems fluctuate…can go into remission particularly early on ….the usual natural history is that flares settle completely and then subsequently many people have flares that don’t settle completely.
In cross examination Dr McGill confirmed his opinion that the November 1991 episode was a “relatively minor one” and the fact that there was no change in the plain x-rays between April 1991 and February 1992 supported the conclusion that there was a “temporary aggravation”. He added that a “plain lateral X-ray of the spine was the best way to follow the progression of a degenerate disc.
In respect to the finding of a protrusion in a CT scan Dr McGill stated, inter alia, the following:
So a protrusion is very important if the person has symptoms that might be due to nerve compression …if the protrusion doesn’t squash a nerve the protrusion is of no added consequence other than the disc is degenerate. So a degenerate can cause pain whether or not it has protruded…an episode of acute disc protrusion can cause an episode of pain even without there being nerve compression...acute large protrusions often resolve themselves… most protrusions are not acute large protrusions and the commonest sort of chronic protrusions don’t tend to resolve, they stay, they’re still evident on imaging…. If they have caused an aggravation of symptoms? The symptoms may continue, but they’re no longer symptoms related to an acute disc protrusion, they’re related to degenerative change in the disc…..studies of back pain and imaging show that we don’t have a correlation between whether or not people have a protrusion and whether they have back pain …there is a reasonable correlation between the degree of degenerative change in discs and whether people are experiencing back pain, but whether a protrusion is there or not doesn’t correlate with back pain.
In response to a question from the Tribunal, as to whether disc degeneration is the only cause of low back pain, Dr McGill answered as follows:
No. It’s a good question in that why does just one person who has a degenerate disc have pain and another person who radiologically has the same finding has not had pain, and we don’t have the answer. Other structures like ligaments and muscles cause pain, yes, they can, they’ve got innovation by pain fibres. That’s why the clinical syndrome is called non-specific low back pain. Although it sounds like a wastebasket type diagnosis it’s an accurate one, because it’s usually impossible in low back pain to actually specify the exact source of the pain, but it’s still common for people with – there is a relationship between degenerative change in the low back measured on radiological studies and the prevalence of low back pain.
Dr McGill was asked to explain what he would consider to be a major incident as compared with a minor incident and answered as follows:
Yes. An example would be a high speed motor vehicle accident, if someone fell off a ladder. These are major incidents. Someone who has an incident, a moderate incident and is immediately in severe pain and goes off to hospital and within days has a neurological deficit appropriate for a nerve being squashed that’s a major incident. The reason I described his incident as minor was based on the history he gave me. He was rolling two pieces of steel trunking [sic] towards himself on the work bench, reached over, felt a tearing sensation in his low back. Initially the discomfort was not marked, he was able to continue his normal work duties, continue those duties over the next week. Not until about a week later he reported the problem because his symptoms had deteriorated. He also recalled performing some overhead drilling about a week after the episode, that he rolled a piece of air conditioning vent, it seemed to aggravate his low back. This to me doesn’t describe a major acute injury.
When asked whether “If somebody has a pre-existing degenerative condition in their spine would it take a lesser incident to render them symptomatic because they have got that pre-existing vulnerability?” Dr McGill answered as follows:
Sure, temporarily, yes. So it can happen spontaneously. With degeneration as I mentioned, but I will say it again, the natural history is to get flares of pain and for most people that I’m looking after clinically, not here, most of those people they can’t recall anything that they did differently on that day. We all do things every day, so people will wonder whether it was the sitting down or the standing up or whatever they do in their normal day, but it’s no different from what they do every other day and yet they get severe – you know, get an episode of pain which can be quite severe. So flares, flare-ups of symptoms are part of the natural history of degenerative disc disease. So it can certainly happen with – if it can happen spontaneously it can also happen with a minor episode, but it doesn’t affect – I don’t think those spontaneous flares or the minor incidents makes a difference to what’s going to happen to that person in the future.
Dr McGill was asked about any relationship between the onset of symptoms in November 1991 “which haven’t settled since on the history that he has given” Dr McGill answered as follows:
Well, it’s not sufficient with that degree of injury and the existence of pre-existing degenerative change and the lack of radiological progression when comparing before and after that incident. It’s not sufficient to say, yes, that’s still having an effect on his back.
In response to a question, as to the significance of the history of “experiencing a tearing sensation, the onset of pain and the subsequent failure of symptoms to settle. Doesn’t’ that suggest a more significant event occurred in November 1991?” Dr Mcgill answered as follows:
The sense of tearing is not a useful – it’s a pain. I don’t think people who report they feel a tearing indicates that that’s the disc, that some change in giving that sensation. I don’t think one is able to perceive the symptom of a disc protruding for example. It can cause pain, but people with simple muscular strains and with no back pain, where there’s no suggestion of any disc protrusion, will also describe often a tearing feeling. The tearing we can put aside in terms of its usefulness. For the rest, it’s a matter of combining all of the information we’ve had and I’ve summarised it repeatedly. I come to the same conclusion, I think they all should be considered, but if you consider all of the information I think the conclusion that I reach is that there was no substantial episode that happened in November 1991, if I’ve got the right date, and that his current symptoms are a reflection of the degenerative changes that had started well before that time.
Additional comments by Dr McGill in respect of specific questions from the Tribunal:
·The diagnosis of “discogenic mechanical back pain”? – We would now call it non- specific back pain. The implication of the description is that the person believes that a degenerate disc is the cause of the pain….I am not against the concept… that of a doctor has the belief that a degenerate disc is the cause of the pain …. in the research studies it’s very difficult to prove in populations that someone who has back pain that it’s specifically the disc in that person as opposed to the facet joint or the ligament that’s causing the pain.
·What do you mean by “aggravation”, pathological change or pain? – Well, I mean both of those would equal an aggravation I thought; one of them a temporary one and one with a permanent change in pathology which may or may not have a permanent change in symptoms associated with them.
·What is your opinion in this instance? – I think it was an increase in symptoms, but not a significant change in the underlying pathology.
·When did the protrusion occur? – we don’t know when it occurred.
·Could the protrusion have occurred before all of, or any one of the episodes of pain? – yes.
·The diagnosis of “soft tissue injury” with reference to the pathology of a degenerative intervertebral disc? – No ?????...refers to the back, the concept of soft tissue injury is a very non- specific, very non- specific term. I mean I don’t know what people really mean by that. If someone has an acute episode of back pain, non- specific low back pain is the better description
·In light of the available evidence, no other corroborative evidence and no alternative explanation, could the single November 1991 episode continue to impact on Mr Rehberg’s current symptoms? – Well, I think it’s very unlikely? …. I mean I think it is very unlikely that the event in November 1991 is continuing to have any influence on his symptoms now. The reason I say that is that we know he had degenerative disc disease in his back prior to 1991. We know that it had caused intermittent symptoms prior to that time, that the plain radiology does not suggest that there was a substantial new injury to the disc between the first plain X-ray and the one in 2018. So bridging over the period of time that that November 1991 incident occurred, and particularly given that the 26 years (indistinct) lapse since then, or about 26 years, if there had been a significant change as a result of that, what historically to me sounded like a minor incident we would expect to see that reflected by that disc having become a lot more degenerate. I presume that’s why the X-ray was done to demonstrate progression, but it didn’t anyway.
·Mr Coombes – In answering the above question is there an underlying assumption that the November 1991 incident didn’t cause the disc bulge or protrusion seen in the CT scan in February 1992?- It doesn’t – I mean the answer doesn’t matter whether the protrusion was influenced by that episode. Do I think it was unlikely that it was caused by it? Yes, I do. But had it been caused by that does it change the overall answer? No, it doesn’t.
Dr S Harbison, orthopaedic surgeon
In a report dated 25 September 2017 Dr Harbison noted Mr Rehberg’s past history of episodic back pain and commented on inconsistences in the histories recorded in past medical reports and letters.
Dr Harbison noted that Mr Rehberg “gets low back which varies in intensity from day to day and on some days has no pain. The pain is situated low down in the lumbar region and sometimes radiates to either buttock and occasionally to the proximal half of the left thigh posteriorly.”
Dr Harbison was not able to view any x-rays, as Mr Rehberg “had been told not to bring any”, but was able review the relevant reports from 1992 and 1996.
Dr Harbison concluded, inter alia, as follows:
Mr Rehberg has degenerative change in his lumbar spine. In the incident on 01 November 1991, he sustained a soft tissue strain.
At the time of the incident he must have had degenerative changes in the spine because the x-ray and CT scan performed three months later show longstanding degenerative changes which could not have developed in the intervening time. The degenerative changes progressed over time and the investigations in 1996 showed more marked changes than were reported in 1992.I presume that there has been further progression since that time and that is the reason for Mr Rehberg is continuing to suffer from some symptoms in his lower back
I do not believe his present condition is related to any particular incident at work on 01 November 1991. From the description given to me and from that given to other doctors, it appears that the incident was relatively minor and occurred on the background of previous lower back problems. Such a minor injury would have resolved by now.
I do not believe that his present condition is related to the specific incident in November 1991 or to his employment in general. The incident was relatively minor in that he was able to continue work and did not need to see his doctor until approximately a week later. [emphasis added]
Dr J. Bentivoglio, orthopaedic surgeon
In a report dated 6 July 2018 Dr Bentivoglio recorded a fairly brief history of Mr Rehberg’s back injuries and noted that he has “low back pain most of the time” with fluctuation in severity and that when “flare-ups of his back symptoms” occur, it generally takes about a week for it to settle
Dr Bentivoglio reviewed the various plain x-rays of Mr Rehberg’s lumbar and stated as follows:
I did view the results of plain x-rays taken of his lumbar spine in April 1991 which did show some decrease in in the L5/S1 disc space as well
I viewed plain X-rays taken of his lumbar spine performed in February 1992. There was evidence of decrease in the L5/S1 disc space but no other significant abnormality.
The most recent x-rays taken of his lumbar spine in 2018 show there has been a small amount of progression in degenerative change at the L5/S1 level since 1996.
With respect to the CT scans of the lumbar spine Dr Bentivoglio stated as follows:
A CT scan taken of his lumbar spine in February 1992 showed a central left sided disc protrusion at the L5/S1 level. This would account for the decrease in the L5/S1 disc space seen on the plain x-rays
I also viewed a CT scan taken of his lumbar spine in 1996, together with plain x-rays at that time. These showed quite significant degenerative change at the L5/S1 level of his lumbar spine. I would consider this to be natural progression of the discal damage seen on the CT scan of his lumbar spine in February 1992
Dr Bentivoglio expressed his opinion as follows:
He had a CT scan taken of his lumbar spine in early 1992, indicating he had a significant L5/S1 disc prolapse. As this man’s symptoms following the two injuries resolved, I would have to assume that disc prolapse occurred as a result of the specific incident on 1 November 1991. That would be in keeping with the history and investigations that he has had.
In a supplementary report dated 23 August 2018 Dr Bentivoglio stated he did not view the x-rays taken in April 1991 and was “not able to compare” with the x-rays taken in February 1992.
In response to questions from Comcare, Dr Bentivoglio made the following statements:
The fact that Mr Rehberg sustained an injury to his back on 1 November 1991 and had a CT scan taken of his lumbar spine in February 1992, would suggest that he had a little more than just a soft tissue injury as he was symptomatic for at least a period of three months. I viewed plain x-rays taken of Mr Rehberg’s lumbar spine and there is no indication that he had any pre-existing degenerative changes in his lumbar spine in February 1992. There is decrease in the L5/S1 disc space but no other abnormality apart from that. [emphasis added
There are no longstanding degenerative changes seen on Mr Rehberg’s lumbar spine on investigations in February 1992. Indeed, there are no signs of any degenerative changes present in his lumbar spine in 1992. I feel the degenerative changes present in his lumbar spine that were seen four years later in 1996 were as a result of the injury on 1 November 1991 and not a result of an aggravation or acceleration of any degenerative change.
As to whether the decrease in the disc space was exactly the same in April 1991 as it was in February 1992, I cannot comment. I do not consider Mr Rehnberg had any degenerative changes present in his lumbar spine on the x-rays and CT scans taken in February 1992. I would consider the discal abnormalities seen in the February 1992 CT scan was a result of the injury in November 1991. [emphasis added]
In his oral evidence, at the hearing, Dr Bentivoglio confirmed that, in his opinion, in November 1991 Mr Rehberg suffered an acute injury at work which damaged his L5/S1 and led to the degenerative changes seen in imaging studies performed in 1992 and 1996. His opinion was based on an assumption that there was no evidence of degeneration prior November 1991 and that prior to the episode at work Mr Rehberg had a perfectly normal L5/S1 disc.
Dr Bentivoglio conceded, however, that degenerative disc disease is “infinitely” more common that acute injury. He also agreed that at age of 30 years degenerative lumbar disc changes, including disc prolapse, can be seen in up to 30% of asymptomatic people.
When pressed on the assumption that there was no evidence of degenerative disc disease prior to November 1991, Dr Bentivoglio conceded there was evidence of disc degeneration on the lumbar x-ray performed in April 1991 However, as he had not viewed this x-ray and did not compare with the 1992 or 1996 x-rays he said he could not comment as to whether the disc space had changed.
Dr Bentivoglio also conceded that he did know when the disc protrusion actually happened.
CONSIDERATION
There is no dispute that in November 1991 Mr Rehberg suffered an “injury” for the purposes of s14 of the SRC Act, in that he suffered low back pain which led to incapacity for work for a period of approximately 4 weeks.
The Tribunal has been asked to determine whether the “injury” suffered in 1991 continued to contribute, to a material degree, to Mr Rehberg’s ongoing and current low back symptoms. In particular, whether as at 26 October 2017 Mr Rehberg continued to suffer any effects of the compensable injury which happened 26 years ago.
In determining this issue, it is useful to consider the kind of injury that Mr Rehberg actually suffered in November 1991
It is agreed that Mr Rehberg suffered a degenerative condition of the L5/S1 intervertebral disc. It is also agreed that medical evidence before the Tribunal indicates that this degenerative condition was present prior to the incident in November 1991. This was demonstrated by the x-ray of the lumbar spine performed on 17 April 1991 which revealed narrowing of the L5/S1 disc.
We note that this is x-ray was arranged by Dr Chua after Mr Rehberg had injured his back at home and that Dr Chua incorrectly recorded in his practice notes “xray NAD”, that is, no abnormality detected.
It is not clear why Dr Chua did not arrange any investigations in respect of the episode in November 1991. We can only assume that he felt that Mr Rehberg’s symptoms were not severe enough to warrant further investigation.
On 21 November 1991 Mr Rehberg lodged a claim for worker’s compensation.
In February 1992, on referral by Comcare, Mr Rehberg was seen by Dr A. Middleton who arranged for plain x-ray and CT scan of the lumbar spine.
In his report dated 19 February 1992 Dr Middleton noted, incorrectly, that the x-ray in April 1991 showed “no obvious abnormality”.
Dr Middleton noted that the x-ray performed on 12 February 1992 showed a “considerably narrowed” L5/S1 disc space and that the CT showed “large posterior protrusion” in the same disc. He then stated that the disc protrusion was related to Mr Rehberg’s “work undertaken during his employment.”
Dr Middleton’s expertise with respect to degenerative spine disease is unclear, particularly as he recommended consultation with an orthopaedic surgeon, Dr J. Cummine.
In May 1992, Dr Cummine noted that the CT scan of 12 February 1992 showed “some degenerate disc disease which is also present on the plain x-rays of 17 April 1991.”
In June 1992, in response to questions from Comcare, Dr Cummine expressed the opinion Mr Rehberg‘s current condition “relates to his employment only in so far as the work has acted as a precipitating or temporary aggravation factor for his underlying degenerate disc disease” and that a reasonable estimation of the duration of the “aggravation” would be a period of 3 to 6 months.

In his letter of 5 August 1992 Dr Giblin recorded a superficial history of injury which referred only to one episode of back pain in September 1990. There was no mention of the episode in November 1991 or any previous episodes. He then stated that the “5/1 disc” protrusion shown on the CT scan was consistent with a “clinical diagnosis of discogenic mechanical back pain”. He did not refer to the plain x-rays or provide any meaningful clinical assessment of Mr Rehberg degenerative spine condition.
Dr Chan in his report of 18 December 1992 noted the three episodes of back pain and the abnormalities on the plain x-rays and the CT but appeared uncertain about the cause of Mr Rehberg back pain. He stated that “it is possible” that the disc protrusion is the cause of his backache” and that he could not say for sure whether the disc protrusion was caused “by any of the three instances”
Dr Chan did not appear to be an orthopaedic surgeon and his expertise with respect to degenerative spine disease, in our view, was questionable.
The Tribunal is satisfied. that in 1992, the opinion of Dr Cummine was the most persuasive and clearly demonstrated that, in November 1991, Mr Rehberg had a pre-existing degenerative condition involving the of the L5/S1 intervertebral disc
We are also satisfied that the cotemporaneous medical evidence did not support a conclusion that the incident at work, in November 1991, caused any pathological or other permanent change in Mr Rehberg’s degenerative L5/S1 intervertebral disc
In his two letters of June 1996 Dr Giblin referred to 3 episodes where Mr Rehberg hurt his back, 1988 at work, 1990 at home and 1991.
There is no evidence of any injury in 1988 and no explanation why this was included in the letter. The incident in 1990 was actually at work and according in Mr Rehberg’s statement he “could not recall needing any time off work. In 1991 there were two episodes, one at work, and one at home and it is not clear to which episode Dr Giblin was referring.
Dr Giblin arranged for a CT scan and plain x-ray and stated that the “repeat CT scan does show some progressive changes at L5/S1 compared to the x-rays 4 years ago. He makes no reference to any of the plain x-rays.
These letters can best be described as superficial and are of little assistance for present purposes.
In his report of 6 March 1997 Dr R. Middleton expresses the opinion that “This man has the residuum of a left L5/S1 prolapse. Because of the increment in the disc narrowing between 17/4/91 and 3/6/96 it is likely that the last incident is the factor which is causing his present disability”
Dr Middleton appears to rely on the radiology reports alone and makes no reference to the 1992 plain x-ray. In our view, his opinion cannot be considered to be reliable.
Mr Rehberg relies on the written and oral evidence provided by Dr Giblin and Dr Bentivoglio.
In his report of 23 August 2018, Dr Bentivoglio stated that “I viewed Xrays taken of Mr Rehberg’s lumbar spine and there is no indication that he had any pre-existing degenerative changes present in his lumbar spine in February 1992. There is decrease in the L5/S1 disc space but no other abnormality apart from that.”
It would appear that Dr Bentivoglio’s understanding of the x-ray features of degenerative disc disease is out of step with the majority of other medical opinion before the Tribunal.
At the hearing Dr Bentivoglio confirmed that, in his opinion, in November 1991 Mr Rehberg suffered an acute injury work which damaged his L5/S1 and led to the degenerative changes seen in later imaging studies. His opinion was based on an assumption that there was no evidence of degeneration prior November 1991 and that prior to the episode at work Mr Rehberg had a perfectly normal L5/S1 disc.
However, it is agreed that that there was evidence of degenerative change in the L5/S1 disc prior to 1991 and, therefore, Dr Bentivoglio’s assumption was not correct.
At the hearing, Counsel for Mr Rehbeg indicated that he was no longer relying on that aspect of Dr Bentivoglio’s evidence.
As this issue is an essential element in the resolution of this matter Mr Rehberg must rely primarily on the evidence of Dr Giblin.
In his report of 22 September 2003 Dr Giblin identified the three relevant episodes of pain as described by Mr Rehberg and states that “his symptoms will persist indefinitely, in terms of exacerbations and remissions and there will gradual deterioration as he gets older” and concluded his current condition “is mainly related to the injury sustained by him in November 1991.”
Dr Giblin indicated that he agrees with Dr McGill’s opinions concerning “the inherited constitutional disorder of lumbar disc disease” but asserted that in his opinion Mr Rehberg’s current disability is related to “material damage from his injury of November 1991 and that this material damage has caused an acceleration of the underlying constitutional condition.”
The difficulty with Dr Giblin’s opinion is that he does not define what he means by the “injury” or “material damage” and does not provide any explanation to support his assertion that there has been an “acceleration of the underlying constitutional inherited condition.”
Furthermore, he appears to confuse the legal question of “continuing contribution to a material degree” by the episode in November 1991 with a medical question of “material damage” to the intervertebral disc.
In his report of 10 November 2017 Dr Giblin noted that there have been no new radiological investigations and that Mr Rehberg’s symptoms “are episodic in nature”.
Dr Giblin introduces a new diagnosis of “soft tissue injury to his low back, related to his injury of 1991” but provides no explanation as to what this means.
Dr Giblin acknowledges that there were “pre-existing degenerative changes in the lumbar spine at least consequent upon the symptoms occurring in 1990.”
Dr Giblin asserts that following the injury in 1991, the nature and conditions Mr Rehberg’s work environment were such that “there was ongoing recurrent material aggravation of his symptoms”. Again, he does not explain what he means by “material aggravation”.
Dr Giblin goes on to express the opinion that Mr Rehberg’s current symptoms and current physical restrictions are related “both to pre-existing degenerative changes and the effects his ongoing injury”. Also, he opined that the effects are “material in nature” and “permanent in character”.
Dr Giblin did not define what the “material effects” are and it would appear that he believes that Mr Rehberg suffers two separate but coexisting conditions.
In his oral evidence Dr Giblin confirmed his belief that Mr Rehberg “continues to suffer from both the degenerative condition and the work-related aggravation.”
When asked whether there is any evidence to support his opinion that the episode in November 1991 actually was the “tipping point of the degeneration”, Dr Giblin said “only the history”.
It was not entirely clear what he meant by “the history” but it appears to be based on Mr Rehberg’s self- report of continuing symptoms that after 26 years “are basically the same”.
Dr McGill in his report of 24 July 2003, based on the fact that the plain x-ray in April 1991 showed chronic degenerative change at L5/S1, concluded that Mr Rehberg had “pre-existing degenerative disc disease” which was present prior to the episodes of back pain at work and at home.
Dr McGill described the episodes at work as “relatively minor” but accepted that these episodes did materially contribute to the severity of Mr Rehberg’s symptoms in the period following those episodes. However, he was of the opinion that these “work related aggravations” were temporary and had probably ceased within 3 months.
Dr McGill rejected the idea that Mr Rehberg’s work duties in 1991 and early 1992 continued to materially contribute to his current condition. He stated that Mr Rehberg’s back condition is permanent but it was probable that “the work- related component was temporary.”
In his report 20 June 2018 Dr McGill stated that he was able to directly compare the plain x-rays of the lumbar spine taken in 1992 and 2018 and concluded despite the 26 year interval the appearances at L5/S1 were similar.
Dr McGill confirmed his opinion that Mr Rehberg’s had a degenerative lumbar disc condition of the L5/S1 disc, which was present prior to 1991, and that this condition was temporarily aggravated by the work he performed “including his work and injury in 1990 and his work duties (without injury) in 1991” and that the duration of the “work aggravation” was less than 3 months on each occasion.
He indicated that his opinion was based on “the nature of work activity/injury,” the presence of chronic degenerative change on the imaging studies in April 1991 and the frequency of imaging findings in the general population in the absence of symptoms.
Dr McGill’s oral evidence at the hearing, which is recorded above in considerable detail is, in our view, sufficiently self -explanatory so that it is not necessary to repeat this evidence again.
However, we do wish to highlight two aspects of his written and oral evidence we consider to be quite persuasive, that is, the importance of a comparative evaluation of the plain x-rays of the lumbar spine in assessing changes in degenerating intervertebral disc and the relevance of the prevalence of imaging findings of spinal degeneration in asymptomatic individuals.
CONCLUSION
After having considered all the evidence the Tribunal is satisfied that the preferable decision is that, in November 1991, Mr Rehberg’s compensable injury was, a temporary aggravation of his pre-existing L5/S1 degenerative disc condition, and that any effects of that aggravation had ceased at an undetermined date in the ensuing 12 months.
The Tribunal is also satisfied that Mr Rehberg’s compensable injury did not contribute to a material degree to his symptoms as at the 26 October 2017 or currently and, therefore, he has no present entitlement to compensation payments pursuant to sections 16 and 19 of the SRC Act
In reaching our decision we have preferred the evidence of Dr McGill. His written and oral evidence provided a comprehensive and balanced assessment of Mr Rehberg’s degenerative spine condition. He supported his opinions with cogent reasoning and also provided some insights into recent advances with respect in diagnostic issues when dealing degenerative spine disease and symptoms of low back pain.
Furthermore, his evidence was, in general, supported by the opinions of Drs Cummine and Harbison.
The Tribunal found Dr Giblin’s evidence to be confused, inconsistent and not well supported by convincing reasons.
He based his opinions on an assumption that, in November 1991, Mr Rehberg suffered an acute and permanent injury to the L5/S1 intervertebral disc which somehow “accelerated” the pre-existing degenerative spine condition, but was unable to point to any convincing evidence to support his opinion.
Dr Giblin’s approach was similar to that of Dr Bentivoglio who had assumed that Mr Rehberg had suffered an acute injury to a “normal” disc. Whereas, Dr Giblin opined that Mr Rehberg had suffered an acute injury to a “vulnerable” disc. Neither doctor adequately considered the relevance of the serial plain x-rays of the lumbar spine.
Furthermore, in our view, Dr Giblin failed to give appropriate consideration to the natural history of a degenerative spine condition over a period of more than 25 years.
DECISION
For reasons set out above the Tribunal is satisfied that in November 1991 Mr Rehberg suffered a compensable injury best characterised as a temporary aggravation of pre-existing degenerative condition of the L5/S1 intervertebral disc.
The Tribunal is satisfied that the compensable injury did not contribute, to a material degree, to Mr Rehberg’s ongoing or current symptoms and that on or about the 26 October 2017 he no longer suffered any effects of that injury.
This means that Mr Rehberg is no longer entitled to compensation payment pursuant to section 16 and 19 of the SRC Act.
The decision under review is affirmed.

I certify that the preceding 174 (one hundred and seventy -four) paragraphs are a true copy of the reasons for the decision herein of Dr I Alexander, Member

................................[sgd]........................................
Associate
Dated: 14 March 2017

Date(s) of hearing: 11, 12 and 13 February 2019

Counsel for the Applicant: Adrian Coombes

Solicitors for the Applicant: Connie Iarossi and Gabriella Giunta, Slater and Gordon Lawyers

Counsel for the Joined Party: Peter Lehmann, Lehmann Snell Lawyers

Solicitors for the Joined Party: Tushaar Garg, Lehmann Snell Lawyers

[2019] AATA 413

14 March 2019

Key Legal Topics

Areas of Law

Employment Law

Statutory Interpretation

Legal Concepts

Causation

Statutory Construction

Remedies

Appeal

Natural Justice

Date(s) of hearing:	11, 12 and 13 February 2019
Counsel for the Applicant:	Adrian Coombes
Solicitors for the Applicant:	Connie Iarossi and Gabriella Giunta, Slater and Gordon Lawyers
Counsel for the Joined Party:	Peter Lehmann, Lehmann Snell Lawyers
Solicitors for the Joined Party:	Tushaar Garg, Lehmann Snell Lawyers