Albright & Wilson (Australia) Limited v Bisson
[2023] NSWPICMP 618
•28 November 2023
| DETERMINATION OF APPEAL PANEL | |
| CITATION: | Albright & Wilson (Australia) Limited v Bisson [2023] NSWPICMP 618 |
APPELLANT: | Albright & Wilson (Australia) Pty Limited |
RESPONDENT: | David Thomas Bisson |
| APPEAL PANEL | |
| MEMBER: | Richard J Perrignon |
| MEDICAL ASSESSOR: | Alan Home |
| MEDICAL ASSESSOR: | Tommasino Mastroianni |
| DATE OF DECISION: | 28 November 2023 |
| CATCHWORDS: | WORKERS COMPENSATION - Appeal from assessment of whole person impairment (right upper extremity); whether the assessor erred in failing to use the contralateral left limb ‘as a baseline comparator’ in accordance with the Guidelines at 2.20; whether he failed to take into account an argument that such a comparator should be used; Held – Medical Assessment Certificate revoked and replaced. |
BACKGROUND TO THE APPLICATION TO APPEAL
The appellant employer appeals from the Medical Assessment Certificate of Medical Assessor Giles dated 23 April 2023.
He assessed a 23% whole person impairment (23% right upper extremity, 0% scarring) as a result of injury on 17 April 2018, when the worker injured his right thumb while pushing a high-pressure hose into a hose coupling in the course of his duties as a maintenance fitter. On 21 August 2018, he came to fusion of the carpometacarpal joint of the right thumb at the hands of Dr Kadir, involving right thumb trapeziectomy and suspension plasty.
The appellant submits that the Medical Assessor erred in his assessment of the right upper extremity only, by:
(a) failing to make a deduction for a pre-existing condition or abnormality pursuant to s 323 of the Workplace Injury Management and Workers Compensation Act 1998, by using the contralateral left limb ‘as a baseline comparator’ as did
Dr Breit, on whose assessment the insurer had relied;(b) failing to explain why he made no deduction, and
(c) failing to take into account the report of independent orthopaedic surgeon Dr Breit dated 29 November 2022.
In accordance with the President’s referral, the Medical Assessor assessed the right upper extremity by reference to impairment of the right thumb, fingers and wrist. The parties agree that he erred when combining the various impairments together. They agree that, when accurately combined, these impairments amount to 29% upper extremity impairment in respect of the right hand, and 6% upper extremity impairment in respect of the right wrist, yielding 33% upper extremity impairment which converts to 20% whole person impairment, rather than the 23% assessed.
Nothing turns on it as, for the reasons given below, the Panel has referred the worker to one of its members for examination and assessment.
The Appeal Panel conducted a preliminary review of the Medical Assessment Certificate in the absence of the parties and in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment (4th edition) (the Guidelines).
Submissions
The parties made written submissions which have been taken into account. The appellant’s submissions are summarised briefly above.
The respondent’s worker’s submissions are not repeated in full, but are summarised briefly below.
(a) in effect, Dr Breit assessed a 21% whole person impairment with respect to the right upper extremity and 12% whole person impairment for the left, and deducted the latter from the former (or thereabouts), to make allowance for a pre-existing condition, without reference to the statutory requirements of s 323 of the Workplace Injury Management and Workers Compensation Act 1998;
(b) Dr Breit’s use of the left arm as a comparator was inappropriate, and the Medical Assessor was entitled to adopt the method he did as a matter of clinical choice;
(c) a different approach to assessment cannot constitute demonstrable error;
(d) the Medical Assessor was not bound to accept the opinion of Dr Breit;
(e) mere difference of opinion between a Medical Assessor and other clinicians is insufficient to establish error or the application of incorrect criteria: Mehenthirarasa v State Rail Authority of NSW [2007] NSWSC 22;
(f) the Medical Assessor found that on 17 April 2023 there was aggravation of previously asymptomatic osteoarthritis;
(g) the history taken by the Medical Assessor and the statement of the worker support a conclusion that there was no contribution by any pre-existing condition to current impairment. There is no evidence of a symptomatic condition before injury, or of prior injury, condition, or impairment in either limb;
(h) the mere existence of pre-existing degenerative change or an abnormality is insufficient to warrant a deduction, and
(i) regardless of the approach taken by Dr Breit, there is no pre-existing condition to which impairment can be attributed.
Use of the left upper extremity as a comparator
In accordance with the Panel’s direction, both parties filed supplementary submissions on whether, in the event that the Panel referred the worker to one of its members for examination, it should include in its assessment 10% upper extremity impairment for excision of an isolated carpal bone in accordance with Table 16-27, AMA 5, page 506, noting that on 21 August 2018 the respondent came to right thumb carpometacarpal trapeziectomy and suspension arthroplasty at the hands of Dr Kadir. Though their submissions differed to some extent, both parties agreed that an appropriate allowance should be made in accordance with Table 16-27.
Chapter 2 of the Guidelines governs the assessment of the upper extremities. It provides as follows at [2.20]:
“When calculating impairment for loss of range of movement, it is most important to always compare measurements of the relevant joint(s) in both extremities. If a contralateral ‘normal/uninjured’ joint has less than average mobility, the impairment value(s) corresponding to the uninvolved joint serves as a baseline and is subtracted from the calculated impairment for the involved joint. The rationale for this decision should be explained in the assessor’s report (see AMA5 Section 16.4c, p 543).” [sic, p 453]
Assessment of the degree of permanent impairment is to be made in accordance with the Guidelines: section 322(1), Workplace Injury Management and Workers Compensation Act 1998. That required the Medical Assessor to apply the provisions of [2.20], which distinct from s 323 of the Act. The Medical Assessor did not use the contralateral limb as a comparator in calculating impairment for loss of range of movement. His omission to do so is unexplained. He did not refer to [2.20] at all. His omission to apply the requirements of [2.20], and to give any reasons for doing so, demonstrate error on the face of the Medical Assessment Certificate, requiring that it be revoked and replaced.
Though it is strictly unnecessary to consider the further grounds of appeal, we do so in deference to the detailed submissions provided by both parties.
Orthopaedic surgeon Dr Breit examined the worker on 2 November 2022 at the request of the insurer. He assessed a 13% whole person impairment (12% right upper extremity, 1% scarring). In doing so, he assessed a 41% right upper extremity impairment, from which he deducted 21% to account for a pre-existing condition or abnormality. The 21% was the degree of left upper extremity impairment demonstrated on assessment of the contralateral, uninjured, left limb.
At [11] of his report, he gave the following reasons for taking this approach – emphasis added:
“There is a deductible proportion. This was an acute injury on top of longstanding degenerative disease. The problem is bilateral and therefore in my opinion it is appropriate to use the left hand and wrist as a comparator which I will indicate below.”
And at [12]:
“As I have indicated, [the left upper extremity] is used as a comparator, and you will see from the evaluation chart that for the digits it is the equivalent of 17% upper extremity impairment. Once again with respect to the left wrist, there was restricted movement and according to AMA Guides Chapter 16, Paragraph 16-4g, that is the equivalent of 5% upper extremity impairment.
Utilising the combined values tables that leads to a total of 21% of the upper extremity.
Therefore the residual amount is 20% right upper extremity impairment which converts to 12% WPI.”
Unfortunately, his use of the term ‘deductible proportion’ is apt to confuse his methodology with a deduction pursuant to s 323. However, he makes no mention in his assessment Table of any deduction of that nature.
Reading his reasons as a whole, we interpret him to mean that he simply used the contralateral limb as a comparator in compliance with Guidelines [2.20].
Whether or not the Medical Assessor read Dr Breit’s report or was aware of it, he made no reference to it, and did not engage the argument which Dr Breit presented in favour of making a deduction for impairment of the contralateral limb. The failure to engage with a substantial argument put by a party amounts to jurisdictional error: Rodger v De Gelder [2015] NSWCA 211. The opinion of Dr Breit, qualified as he was by the insurer, amounted to a substantial argument put by or on behalf of a party. The failure to engage with it demonstrates error on the face of the Medical Assessment Certificate requiring that it be set aside and replaced.
At [26] of its submissions, the insurer puts in issue the failure to make a deduction pursuant to s 323:
“MA Dr Giles has not provided any explanation or indication he considered whether there should or should not be a deduction under section 323 based on the baseline non-work related impairment to the left upper extremity as opined by Dr Breit. This is a critical error.”
As indicated, we do not accept that Dr Breit made a deduction pursuant to s 323. The insurer’s submissions discloses a misunderstanding of the method adopted by Dr Breit. In any event, the submission is confined to an allegation that there should have been a deduction by reference to the range of movement in the contralateral (left) upper limb.
Referral for examination
As the Medical Assessor omitted to measure motion loss in the uninjured (left) upper extremity, it was necessary for the Panel to refer the worker to one of its members, Medical Assessor Home, for examination. For the purpose of comparing motion loss in both upper limbs accurately, it was appropriate to assess them contemporaneously in the one examination. His report follows:
“Report of Medical Assessor Home
Mr Bisson attended the rooms of panel member Dr Home on Thursday 28 September 2022. He was unaccompanied.
PAST HISTORY
Mr Bisson denies any prior history of the right or left hand complaints prior to the subject accident.
He worked as a maintenance fitter for his employer Albright and Wilson Australia Pty Ltd for a period of eight years. Prior to that, he had worked as a maintenance fitter for other organisations throughout his working life.
DETAILS OF SUBJECT ACCIDENT
On 17 April 2018, he was pushing a high pressure hose into a hose fitting, when he experienced sudden pain in his right thumb. He indicated the pain he felt was along the line of the right first metacarpal extending from the carpometacarpal joint at the wrist to the first metacarpophalangeal joint. He subsequently received a period of conservative management.
TREATMENT
He underwent CT scan imaging of the right thumb, performed on 4 May 2018 with a finding of mild osteoarthrosis of the carpometacarpal joint.
Subsequently, he underwent surgical treatment under the care of Dr Kadir, on 21 August 2018 consisting of a right thumb carpometacarpal trapeziectomy and suspension arthroplasty performed at Campbelltown Private Hospital.
Subsequently, he developed symptoms of complex regional pain syndrome, for which he was treated with Lyrica and Endep. He recalls no immediate benefit.
He came under the care of Dr Deshpande, pain therapy physician, who performed a series of two or three stellate ganglion blocks at Nepean Private Hospital. He recalls that there was no symptom benefit from the procedures conducted between February and April 2019.
Subsequently, he underwent removal of the original implant and a revision of the right thumb carpometacarpal arthroplasty, performed by Dr Kadir at Campbelltown Private Hospital.
On 5 November 2019, he underwent fusion of the thumb metacarpophalangeal joint (MCP) under the care of Dr Kadir at Southwest Private Hospital.
Subsequently, he came under the care of Dr Nandapalan, orthopaedic surgeon. He underwent a fusion of the right thumb carpometacarpal (CMC) joint at Nepean Private Hospital.
Due to failure of the initial fusion, he underwent a repeat of the right thumb carpometacarpal joint fusion incorporating bone graft harvested from his left iliac crest on 2 March 2021.
On 7 December 2021, he underwent removal of hardware from the thumb metacarpophalangeal joint associated with local tenolysis procedure performed at Nepean Private Hospital.
Physiotherapy treatment has now ceased. Early symptoms of complex regional pain syndrome resolved.
He describes occasional sensation of local skin sensitivity but there is no autonomic or dystrophic change in the thumb.
He reports current use of Panadeine Forte once fortnightly and paracetamol also once fortnightly. He takes medication to manage his other medical complaints including Type 2 Diabetes.
CURRENT SYMPTOMS
Mr Bisson states that he experiences intermittent activity-related pain felt along the line of the first metacarpal bone extending from the carpometacarpal to the metacarpophalangeal joint and also in the first dorsal web space.
The ache occurs during cold weather and in the mornings and post-activity. Consequently, he has taken to use his left hand for almost all activities of daily living including brushing his teeth, toileting and reaching for doorknobs.
There is no active motion at the thumb carpometacarpal and metacarpophalangeal joints, which have been fused.
He denies any pain symptoms in the contralateral left thumb.
FUNCTIONAL CAPACITY AND REPORTED TOLERANCES
He is right hand dominant. There is normal tolerance for most activities of daily living barring the normal use of his right hand.
SOCIAL HISTORY
Mr Bisson is married with two children. He lives in a granny flat associated with a house in which one of his sons reside.
He does engage in very light domestic chores such as dishwashing and bench height cleaning. He potters in the garden.
He has not resumed work since his injuries. He now considers himself retired.
EXAMINATION FINDINGS
On examination, there is evident wasting of the right thumb, secondary to disuse following his right thumb carpometacarpal and metacarpophalangeal joint fusions. There is mild stiffness at the right wrist measured as follows. Flexion 35°, extension 60°, ulna deviation 15° and radial deviation 10°.
This compares with motion at the left wrist measured as follows. Flexion 55°, extension 75°, ulna deviation 35° and radial deviation 20°.
IMPAIRMENT
I have set out the examination findings in relation to the digital motion in the attached upper extremity impairment evaluation records.
There is mild impairment of motion at the non-injured left thumb and further mild impairment of motion at the joints of the left index finger, as set out in the attached impairment evaluation records.
Overall, the level of impairment in the index, middle, ring and little fingers is almost identical between the hands.
However, the right thumb motion impairment is 34%, compared to 1% on the non-injured left side.
In addition to impairment for restricted wrist motion, a further 10% upper extremity impairment rating is determined using Table 16-27, AMA 5, page 506, with excision of an isolated carpal bone rated at 10%.
The overall upper extremity impairment rating for the right upper extremity is 50% and for the left 9%. Subtracting 9% from 50%, there is a final upper extremity impairment rating of 41% for the right upper extremity.
Using Table 14-39, this converts to a whole person impairment rating of 25% WPI.
The main reason for the disparity between this assessment and that of Assessor Giles is the disparity in the measurements of the range of motion in adduction and opposition at the left thumb carpometacarpal joint of the thumb. The carpometacarpal joint has been fused in a position of 0° adduction and opposition and there is no active carpometacarpal joint motion from these positions.”
Assessment
Having regard to his clinical expertise and experience, the Panel accepts the clinical observations and measurements of Medical Assessor Home. Having regard to his measurements, it accepts that the right upper extremity attracts a 50% upper extremity impairment, and that the left attracts a 9% upper extremity impairment.
Applying the Guidelines at [2.20], it subtracts 9% from 50% to yield 41% upper extremity impairment for the right upper extremity, which converts to 25% whole person impairment.
No submission is made that there should be a deduction on any basis other than by using the left upper extremity as a comparator. That has been done.
Conclusion
The Medical Assessment Certificate of Medical Assessor Giles is revoked and replaced with the attached Medical Assessment Certificate.
PERSONAL INJURY COMMISSION
APPEAL PANEL
MEDICAL ASSESSMENT CERTIFICATE
Injuries received after 1 January 2002
Matter number: | W381/23 |
Applicant: | David Thomas Bisson |
Respondent: | Albright & Wilson (Australia) Pty Limited |
This Certificate is issued pursuant to s 328(5) of the Workplace Injury Management and Workers Compensation Act1998.
The Appeal Panel revokes the Medical Assessment Certificate of Medical Assessor Giles and issues this new Medical Assessment Certificate as to the matters set out in the Table below:
Table - whole person impairment (WPI)
| Body Part or system | Date of Injury | Chapter, page and paragraph number in SIRA guidelines | Chapter, page, paragraph, figure and table numbers in AMA5 Guides | % WPI | WPI deductions pursuant to S323 for pre-existing injury, condition or abnormality (expressed as a fraction) | Sub-total/s % WPI (after any deductions in column 6) |
| Right upper extremity | 17.04.’18 | Chapter 2 pages 10-11 points 2.1-2.8 | Chapter 16-1a pages 435-439 pages 455-460 Tables 16-1, 16-2, 16-3 Figures 16-12, 16-15, 16-18, 16-19 Tables 16-8a, 16-8b, 16-9 | 25% | nil | 25% |
| The skin | 17.04.’18 | Chapter 14 pages 73,74 Table 14.1 | Chapter 8.7 page 178 Table 8-2 | 0% | 0 | 0% |
| Total % WPI (the Combined Table values of all sub-totals) | 25% | |||||
0
2
0