Haack and Military Rehabilitation and Compensation Commission

[2006] AATA 355

Administrative

Appeals

Tribunal

 

DECISION AND REASONS FOR DECISION [2006] AATA 355

ADMINISTRATIVE APPEALS TRIBUNAL      )

)          No Q2005/81

VETERANS’ APPEALS DIVISION		)
Re		SCOTT HAACK

Applicant

And MILITARY REHABILITATION AND COMPENSATION COMMISSION

Respondent

DECISION

Tribunal Ms M J Carstairs, Member
Dr M Denovan, Member

Date18 April 2006

PlaceBrisbane

Decision The Tribunal affirms the decision under review. 

..............................................

M J Carstairs
  Member

CATCHWORDS

COMPENSATION – aggravation of spondylolisthesis – aggravation of disc degeneration – whether condition congenital or developmental – condition not causally linked to work – condition did not ‘result in’ permanent impairment - decision affirmed.

Safety Rehabilitation and Compensation Act 1988 s4, 24

Martin v Australian Postal Corporation [1999] FCA 655
Baker and Commonwealth of Australia (1988) 16 ALD 784
Darling Island Stevedoring and Lighterage Co Ltd v Hankinson (1967) 117 CLR 19

REASONS FOR DECISION

18 April 2006	Ms M J Carstairs, Member
Dr M Denovan, Member

1.      Scott Haack joined the Australian Army and served for a ten year period from 1991 to 2001. Mr Haack then took voluntary discharge from the Army and subsequently has worked as a machine operator for a switchboard manufacturer.  Mr Haack now seeks to be paid a lump sum payment for permanent impairment in respect of a back condition. This back condition has been accepted for compensation purposes as an aggravation of spondylolisthesis at L5/S1 and disc degeneration at L4/L5 and L5/S1.  He claimed compensation for that condition just prior to leaving the Army.  That is his identified injury.

2.      The respondent says that even if it were found that Mr Haack had permanent impairment for his back equating to 10% whole person impairment, which is the percentage level required under the Safety Rehabilitation and Compensation Act 1988 before any lump sum payment can be made, Mr Haack does not satisfy the preliminary requirement in the legislation that permanent impairment must arise from the injury.    

3.      Under the heading Principles of Assessment, the Introduction to the Guide to the Assessment of the Degree of Permanent Impairment, states that impairment is measured in terms of the effects on personal efficiency in daily living in comparison with a normal healthy person.  There was no dispute that Mr Haack has a permanent impairment of his back.  Section 4 of the Act defines impairment as the loss, the loss of the use, or the damage or malfunction, of any part of the body or of any bodily system or function of part of such system or function, while permanent is defined as likely to continue indefinitely.  

4.      In accepting the parties agreed position that Mr Haack has a permanently impaired back, we took into account the matters relating to permanent impairment set out in s24(2) of the Act, and the medical evidence which all supported a finding that he suffers from a permanent impairment to his lower back and we so find, there being no medical evidence that suggested otherwise. 

5.       The only Table in the Guide under which Mr Haack’s lower back condition can be assessed, if we are satisfied that he may be assessed at all under this legislation, is Table 9.6 which deals with impairment of the thoraco-lumbar spine.  Mr Haack’s back condition might be assessed under other Tables in the Guide if he had neurological consequences from his spinal condition in addition to having lost some range of spinal movement.  Mr Haack’s evidence, confirmed by the medical evidence, was that he suffers no neurological symptoms, so assessment is confined to Table 9.6, which provides the following descriptions for a person who has impairment at the levels of 5% and 10%:

5  Minor restrictions of movement

10                  Loss of less than half normal range of movement

THE ISSUES

6.      Section 24 of the Act sets out:

24(1)Where an injury to an employee results in a permanent impairment (emphasis added), Comcare is liable to pay compensation to the employee in respect of the injury.

Mr Haack’s compensable injury – which is the injury referred to in s24 is aggravation of spondylolisthesis at L5/S1 and disc degeneration at L4/L5 and L5/S1. 

7.      The first issue that arises is whether Mr Haack’s injury resulted in permanent impairment.  The second issue is the percentage level of that permanent impairment, as assessed under Table 9.6 of the Guide. 

DID MR HAACK’S INJURY RESULT IN PERMANENT IMPAIRMENT?

8.      Much of the medical evidence dealt with the nature and aetiology of the spondylolisthesis which Mr Haack suffers.  A spondylolisthesis is a forward shift of one vertebra upon another, most usually the 5^th lumbar vertebra over the sacrum or the 4^th lumbar over the 5^th lumbar vertebra, due to a defect in the joint at the pars interarticularis (or neural arch).  All the medical practitioners who provided reports on Mr Haack – that is Dr P Boys, orthopaedic surgeon, Associate Professor B McPhee, spinal orthopaedic surgeon, Dr A Nowitzke, neurosurgeon, Dr B Purssey, specialist in general surgery and orthopaedics, and Dr J Rowe, occupational physician - agreed that spondylolisthesis was the correct diagnosis and agreed further that Mr Haack suffers the isthmic kind. 

9.      The full description of Mr Haack’s lower back condition is that he has an isthmic spondylolisthesis with degenerative changes in L4/L5 and L5/S1 consistent with lumbar spondylosis.  This description comes from Associate Professor McPhee’s report (exhibit R2) but was consistent with the descriptions given by all other medical practitioners, those descriptions deriving from observed changes in the spine appearing in x-rays taken in 2001.  The doctors all agreed that diagnosis of the condition is based on radiological evidence rather than on clinical signs.  We heard that in the usual case a person will present with back problems and x-rays are conducted, from which the defect in the pars interarticularis is revealed, and this is definitive of the condition.

10.     Dr Boys gave evidence that the defect or weakness in the bone in the pars interarticularis causes the vertebra to move forward.  In his oral evidence Dr Boys said that the defect leads to segmental instability, and the disc is not strong enough to prevent forward movement.  This is why the listhesis (or dislocation of the vertebra) develops.

11.     There was much debate between the specialists about whether spondylolisthesis is a congenital or a developmental condition.  Dr Boys said that the isthmic kind of spondylolisthesis is not congenital.  Dr Nowitzke used the term congenital (T8) but explained in his oral evidence that he meant that the pars defect is present from birth, although the spondylolisthesis comes later.  He said it is unusual to see spondylolisthesis in children.  Dr Boys agreed that the condition, of which there is a 5% incidence in the general population, is generally not seen before six years of age.  Dr Rowe suggested a 5%-8% incidence in the population, noting that it is mostly asymptomatic.  

12.     Dr Boys said that whilst we do not completely understand how the condition progresses, it is most likely that, as the young person develops, their spine extends and this places stress on the area of weakness in the pars interarticularis.  Both Dr Boys and Associate Professor McPhee told us that spondylolisthesis can occur under acute impact, but this would require a very high impact injury or a major extraneous force (exhibit R2) such as might be sustained by a parachutist or in a high velocity car accident.

13.     On the other hand, both Dr Rowe and Dr Purssey stated that it was highly unlikely that Mr Haack had the condition prior to commencing in the Army.  Dr Purssey said that the use of a term such as developmental was unhelpful.  He said that Dr Nowitzke was incorrect in stating that isthmic spondylolisthesis was congenital. However in his oral evidence Dr Purssey acknowledged that he would defer to Associate Professor McPhee as the acknowledged specialist in the area.  He said that he agreed with Associate Professor McPhee’s statement that spondylolisthesis is a developmental condition which is usually evident before or during adolescence, apart from the problem Dr Purssey had with the use of the word developmental. 

14.     Dr Rowe said that he considered that Mr Haack’s spondylolisthesis could be congenital and/or hereditary but mostly it is due to fracture of the pars interarticularis (T5b).  He said however that other doctors had not sufficiently acknowledged that the condition may be associated with trauma (T11).  Dr Rowe considered that because Mr Haack first experienced back pain while he was in the Army, without any previous injury, his back condition is causally related to the activities that took place while he was in the army for 10 years (T5b).   In oral evidence he said that although Mr Haack may have had a congenital abnormality, it was asymptomatic before his service.  He said that he believed that had Mr Haack not been in military service he would not have suffered with serious back problems (T11).  He said that without x-ray evidence earlier than 2001, it was impossible to say whether Mr Haack’s spondylolisthesis was acquired or congenital.

15.     Dr Rowe cited a publication in E Medicine that said that spondylolisthesis is believed to be caused by repeated micro-trauma resulting in stress fractures of the pars interarticularis.  In oral evidence Associate Professor McPhee said, however, that the error in that proposition was the omission of any reference to the inherited weakness in the pars interarticularis which prevents healing and allows the area to break down.

16.     Associate Professor McPhee is an acknowledged spinal expert who has written on and researched spondylolisthesis extensively.  He said that there is no question that spondylolisthesis in almost all cases is genetic.  Whilst not congenital, he said, it is inherited.  In the most common form, namely isthmic spondylolisthesis, will be evident in males before growth ceases, at the age of fifteen or sixteen.  In his written report (exhibit R2) he stated:

“On the balance of probability, spondylolisthesis of L5 on S1 and the degeneration in the corresponding disc is long standing and pre-dated his enlistment.  This is a developmental condition which is usually evident before or during adolescence.  The incidence does not arise significantly thereafter.  Furthermore the degeneration and retrolisthesis of the L4/5 disc is secondary to the spondylolisthesis.  The retrolisthesis is a spinal adjustment to compensate the anterolisthesis of the lumbosacral level which inevitably results in degeneration of the L4/5 disc.”

17.     After hearing the evidence of Associate Professor McPhee and Dr Boys we were satisfied that the relevant research confirms that the condition is a genetic one.  The genetic precondition commences a process whereby weakness in the pars interarticularis leads to stress fractures in the neural arch, and this moves onto dislocation of the vertebra.  We accept the evidence of Associate Professor McPhee and Dr Boys in preference to that of Dr Rowe and Dr Purssey who both favoured the view that trauma would have a causative role, because the former medical practitioners are acknowledged spinal experts and were in the best position to speak authoritatively on the subject.  We do not accept Dr Rowe’s opinion that the condition can be caused by micro-trauma.  Dr Rowe does not have the expertise in spinal injuries held by the other specialists, and we concluded that he misinterpreted the role that trauma can play.  We accept the evidence of Dr Boys, Dr Nowitzke and Associate Professor McPhee that trauma would have to be severe to have a causative role in spondylolisthesis and we accept that Mr Haack has not sustained any severe trauma during the incidents he cites in his Army service.

18.     Mr Haack first experienced back problems in the Army in 1993 when trench digging during field exercises.  He did not report this incident, but we accept that it occurred despite the absence of any medical record of it.  He had two other episodes of back pain, both being reported to the regimental aid post, these occurring during Army physical training in 1997 and 1998.   In each of these incidents the medical records show that there was back pain, or muscle strain, and no fitness downgrading resulted from either.  In the records of the 1997 incident the doctor recorded: take x-rays if it does not settle.  We can infer that the episode did settle; Mr Haack did not return for further treatment.   Another incident which took place while Mr Haack was playing rugby in 1995 had no relevance to his current claim because Mr Haack sustained a neck injury not a back injury at that time. 

19.      When Mr Haack was approaching his discharge from the Army in 2001, he reported to a medical practitioner that he had a six year history of back pain.  We accepted Mr Haack’s evidence that he did have a number of incidents of back pain during his service, covering roughly that duration.  Mr Haack was convincingly honest in giving evidence and did not exaggerate his injuries, openly admitting when he did not fully recall all circumstances, and prepared to acknowledge where he might have been mistaken about certain events.  Mr Haack told us that he continued to experience episodes of back pain after leaving the Army, not frequently, but sometimes leaving him unable to move at all.  In one of these episodes in December 2005 he required a 7-day course of anti-inflammatory medication (exhibit A1). We accept his evidence on his continuing back problems.

20.     Dr Purssey said that where a person has episodes of back pain such as Mr Haack experienced from time to time in his Army service there is disruption of tissue, which may involve partial tears which, in healing, develop fibrous tissue.  He said that the person is then more susceptible to further injury.   Dr Purssey said, based on his clinical and Army experience, that there is a high incidence of low back pain in the Army and he believes that the rigour of fitness demands for the Services is underestimated.   As was seen above, Dr Rowe took a similar position, referring to Mr Haack’s back condition as being related to his various physical activities including the requirement to lift 30kg packs and participate in general training.  He said (T5b):

The onset of the back pain occurred for the first time while he was in the Armed Services, he had no previous history of injury, therefore it is related causally to the activities that took place while he was in the army for 10 years.

21.     Dr Rowe did not agree with Dr Boys’ evidence that Mr Haack experienced only temporary episodes of back strain during his Army service.  However he did agree that the degenerative changes in Mr Haack’s discs pre-existed the x-ray evidence of them in 2001.   Dr Boys said that the changes that were evident in Mr Haack's x-rays undertaken in 2001 were undoubtedly long-standing.  He said that the presence of degenerative changes at two levels, L4/L5 and L5/S1, also supported a conclusion that Mr Haack’s spondylolisthesis was a long-standing condition, dating from his teenage years.  Dr Nowitzke (T8) agreed that Mr Haack had the condition for a number of years, long before he joined the Army.

22.     Dr Boys said that the evidence showed that Mr Haack had several episodes where he had symptoms of back pain and required changes to his duties, but in none of these incidents were there any significant symptoms, or the need for bed rest, or any rehabilitation.  He concluded that Mr Haack’s spondylolisthesis was made symptomatic but was not worsened or accelerated at these times.  Dr Nowitzke agreed, stating that while he was happy to accept that Mr Haack had acute episodes of back pain in his Army service, these were temporary and there was no evidence that there was any worsening of the spondylolisthesis itself (T8).  In oral evidence Dr Nowitzke said that there was no evidence that any form of bending, or lifting or employment or occupational factors makes any difference to spondylolisthesis. Dr Nowitzke said that he believed that Mr Haack would be exactly the same whether or not he had gone into the Army.

23.     It is fair to say that this also succinctly expresses Associate Professor McPhee’s view.  He stated that regardless of whether Mr Haack joined the Army he would have developed, at some stage in the first half of his adult life, lumbosacral symptoms (exhibit R2).  He said that the injuries in his military service might have exacerbated his pre-existing condition but it was an aggravation without progression of impairment (exhibit R2), a view that we understood as agreeing with Dr Boys’ that Mr Haack’s underlying condition was made symptomatic but was not worsened or accelerated.

24.     As to the relationship, if any, between the spondylolisthesis and the derangement of the discs at L5/S1 and L4/L5, Dr Rowe said these were associated conditions (T5b and T11).  Associate Professor McPhee said that the degeneration and retrolisthesis of the L4/L5 disc is secondary to the spondylolisthesis, as it is a spinal adjustment to compensate the anterolisthesis of the lumbosacral level which inevitably results in degeneration of the L4/L5 disc.  Dr Nowtizke and Dr Boys agreed.

25.     We concluded on the basis of this evidence that Mr Haack had an underlying condition, or as expressed in the compensation determinations, two underlying conditions (namely, spondylolisthesis at L5/S1 and disc degeneration at L4/L5 and L5/S1) that were related to each other but were not related to his employment in the Army.  We were satisfied, accepting the evidence of the specialists Dr Nowitzke, Dr Boys and Associate Professor McPhee that Mr Haack’s episodes of back pain in 1993, 1997, and 1998, were temporary.  We accept that Mr Haack may have been more susceptible to back pain because of his spondylolisthesis; however the spondylolisthesis itself was unrelated to employment.  We accept the evidence of Dr Boys and Dr Nowitzke that Mr Haack would have recovered fully from his temporary episodes of back pain during his Army service.  That is, incapacity was temporary and did not lead to, or result in, lasting impairment: Darling Island Stevedoring and Lighterage Co Ltd v Hankinson (1967) 117 CLR 19.

26.     Mr King-Scott submitted that Mr Haack’s case presented similar facts to those considered by the Federal Court case of Martin v Australian Postal Corporation [1999] FCA 655, but we disagree. In Martin  the decision maker had concluded that the accident Mr Martin sustained added its measure, in a material degree, to an underlying but previously asymptomatic condition, causing an aggravation or acceleration of his condition (par 30).  In Mr Haack’s case, we have expressly found to the contrary.  

27.     To summarise: we were satisfied accepting the evidence of Associate Professor McPhee that both conditions, that is the spondylolisthesis and the degeneration of the two lumbar discs, were aggravated by Mr Haack’s military service without accelerating the underlying process.   We accept that the two conditions of spondylolisthesis and degeneration at the two lumbar discs were related to each other, connected through the natural progression of disease or injury that is genetic in origin.  We were satisfied that neither condition was caused by Mr Haack’s service. 

28.     It follows from this that Mr Haack’s claim for permanent impairment must fail.   He suffers permanent impairment, but it is as a result of underlying conditions which are not work-related.  This means he cannot show permanent impairment which results from injury which is the necessary precondition to entitlement under s24 of the Act.   We note that our conclusions are in broad agreement with the Tribunal’s decision in Baker and Commonwealth of Australia (1988) 16 ALD 784 where, similarly, the Tribunal considered the question of whether periods of incapacity relate to aggravation or acceleration of underlying disease or to the natural progression of the disease, exacerbated by serial episodes of strain.

WHAT IS THE CORRECT ASSESSMENT OF MR HAACK’S LEVEL OF IMPAIRMENT?

29.     Although strictly unnecessary to do so in view of our findings above, we will address, for completeness, the evidence concerning the rating of Mr Haack’s permanent impairment under Table 9.6, as this was discussed extensively at the hearing.

30.     Different conclusions were reached by the medical practitioners about Mr Haack’s percentage loss under Table 9.6, although all the doctors agreed that test results can vary in assessments by practitioners at different times, depending on the person’s symptoms at the time.  Mr Haack told us that his back symptoms are variable, but that during all assessments, he was trying his best.  We accept that Mr Haack was not consciously exaggerating his symptoms during examinations.

31.     Dr Rowe assessed Mr Haack as having a loss of less than half the range of movement of the thoraco-lumbar spine (that is, satisfying an assessment of 10% under Table 9.6).   Dr Purssey agreed that Mr Haack should be assessed at 10% under Table 9.6 and we noted Dr Nowitzke’s comment that he considered Dr Purssey was well qualified to conduct these assessments.  Dr Boys acknowledged in his oral evidence that an assessment of 10% under Table 9.6 was probably fair, as Mr Haack demonstrated a more than minor reduction in range of flexion. 

32.     Dr Nowitzke considered that Mr Haack demonstrated only minor loss of range of movement (that is, 5% under Table 9.6) though he agreed that assessments are qualitative and will reflect symptoms experienced on the day. However, of all the specialists reporting on Mr Haack’s back, only Associate Professor McPhee carried out testing of flexion in the seated position in addition to standing.  He recorded that Mr Haack’s voluntary flexion was reduced to 20 degrees standing but, when seated with legs extended, he could reach one quarter of the way down his shin, which was equivalent to 60 degrees of flexion. He concluded that Mr Haack was voluntarily limiting his range of movement in the course of his examination. 

33.     The Tribunal preferred the conclusion of Associate Professor McPhee, supported by Dr Nowitzke, that the applicant rates an assessment of 5% under Table 9.6 to the conclusion of Dr Purssey, Dr Boys, and Dr Rowe that the applicant should be assessed at 10% for two reasons.  Firstly, only Associate Professor McPhee tested flexion in both the seated and standing positions, allowing a cross-check of results from each in order to correctly assess true limitation.  Secondly we took into account Mr Haack’s evidence that his symptoms are variable, and that his episodes of severe limitation occur infrequently.  This suggests that caution should be exercised where there are different results recorded from examinations.  It is more likely than not that Mr Haack’s permanent loss is better reflected in the minimum figures rather than the maximum ones recorded.  As a consequence, even had we been satisfied (which we were not) that Mr Haack suffered ongoing back injury that related to his Army service, we would not be satisfied that he could be paid because s24(7) of the Act prevents payment where an assessment is less than 10% under the Guide.

DECISION

34.     The Tribunal affirms the decision under review.

I certify that the 34 preceding paragraphs are a true copy of the reasons for the decision herein of Members Ms M J Carstairs and Dr M Denovan.

Signed:         .....................................................................................
  Legal Research Officer

Dates of Hearing  20-21 March 2006
Date of Decision  18 April 2006
Counsel for the Applicant         Mr R King-Scott
Solicitor for the Applicant          D’Arcy’s Solicitors
Counsel for the Respondent     Mr C Clark
Solicitor for the Respondent     Dibbs Abbott Stallman