Walton v Aus 10 Rhyolite Pty Ltd

DETERMINATION OF APPEAL PANEL
CITATION:	Walton v Aus - 10 Rhyolite Pty Ltd [2023] NSWPICMP 513
APPELLANT:	Michael Walton
RESPONDENT:	AUS-10 Rhyolite Pty Limited
APPEAL PANEL
MEMBER:	Paul Sweeney
MEDICAL ASSESSOR:	Alan Home
MEDICAL ASSESSOR:	Doran Sher
DATE OF DECISION:	13 October 2023
CATCHWORDS:	WORKERS COMPENSATION - Worker alleges that in failing to consider gait derangement and section 17.2c of the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th ed, the Medical Assessor did not deal with a clearly articulated argument in respect of assessment of his right lower extremity; Held – failure to consider the appellant’s assessment constituted error; after reassessment Panel held that gait derangement inappropriate methodology for assessment; Guidelines chapter 3.10 applied; muscle strength considered to be the most appropriate method of assessment; Medical Assessment Certificate revoked.

BACKGROUND TO THE APPLICATION TO APPEAL

On 28 June 2023, Michael Walton (the appellant) lodged an Application to Appeal Against the Decision of a Medical Assessor. The medical dispute was assessed by Dr Farhan Shahzad, a Medical Assessor, who issued a Medical Assessment Certificate (MAC) on
31 May 2023.
The appellant relies on the following grounds of appeal under s 327(3) of the Workplace Injury Management and Workers Compensation Act 1998 (1998 Act):
· the assessment was made on the basis of incorrect criteria, and
· the MAC contains a demonstrable error.
The delegate is satisfied that, on the face of the application, at least one ground of appeal has been made out. The Appeal Panel has conducted a review of the original medical assessment but limited to the ground(s) of appeal on which the appeal is made.
Rule 128 of the Personal Injury Commission Rules 2021 (PIC Rules) and Procedural Direction PIC7 - Appeals, reviews, reconsiderations and correction of obvious errors in medical disputes set out the practice and procedure in relation to the medical appeal process under s 328 of the 1998 Act. An Appeal Panel determines its own procedures in accordance with r 128(1) of the PIC Rules.
The assessment of permanent impairment is conducted in accordance with the SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4^th ed
1 March 2021 (the Guidelines) and the American Medical Association Guides to the Evaluation of Permanent Impairment, 5^th ed (AMA 5).

RELEVANT FACTUAL BACKGROUND

The appellant was formerly employed by Aus-10 Rhyolite Pty Limited (the respondent) as a quarry supervisor at its operations at Tinda Creek Quarry.
On 14 January 2021, while standing on the edge of a tailing pond, the applicant slipped and fell heavily in the mud at the edge of the pond. He was assisted by fellow workers and driven to the Hawkesbury Hospital where he was diagnosed with a ruptured quadricep tendon of the right knee. He was admitted to hospital under the care of Dr Khatib, an orthopaedic surgeon, who performed a repair of the quadriceps tendon on the evening of 14 January 2021. He was discharged from hospital on 16 January 2021.
Unfortunately, the appellant experienced increasing symptoms in his right leg. On
18 May 2021, following an MRI, Dr Khatib identified a secondary rupture of the quadricep tendon.
The appellant underwent further surgery on 7 June 2021, at Nepean Hospital. Titanium screws were inserted into the kneecap to secure the tendon and minimise the prospect of a repeat separation.
After a period of convalescence, the appellant was certified as fit to return to his pre-injury duties on 21 October 2021. At that stage, the respondent terminated his employment. On 7 March 2022, he returned to work in a full-time role as an environmental officer with the Soil Conservation Service of NSW.
The appellant says that he continues to suffer pain and restriction of movement in his right leg brought on by activity. He says that he experiences increased pain on steps, slopes or uneven ground. He walks with a limp.
The appellant developed pain in his low back and right buttock during his convalescence which he attributes to “altered posture after the secondary repair surgery”. He has undergone treatment for this condition from his general practitioner, Dr Guneratne.
On 29 August 2022, the appellant saw Dr Charles New, an orthopaedic surgeon, at the request of his solicitor for the purpose of assessment of permanent impairment resulting from the injury of 14 January 2021. Dr New diagnosed the appellant as suffering chondromalacia patellae, deconditioning of the quadriceps tendon, and patellar maltracking of the knee. He accepted that the appellant suffered low back pain as a result of altered gait.
Dr New expressed the opinion that the appellant suffered 22% whole person impairment (WPI) as a result of his injury. He attributed 15% WPI to the appellant’s right knee noting that knee pathology “can be assessed separately or as per Derangement of Gait”. He continued:
“A decision was made to use Derangement of Gait as it more accurately represents the problems that this patient has had, not only with gait, but also the consequential lumbar spine condition.”
On 10 November 2022, Dr Woo, an orthopaedic surgeon provided a report to the respondent’s insurer by which he assessed the appellant’s WPI as a result of the injury on
14 January 2021. He expressed the opinion that the appellant suffered 6% WPI. He attributed 4% WPI to the right lower extremity in respect of injury to the quadriceps tendon and 2% WPI for scarring. In respect of the right lower extremity, he stated:
“There is no specific guideline for the assessment of impairment for quadriceps tendon rupture. He has a limping gait but does not require any walking aid. There is no leg length discrepancy. The most appropriate and reproduceable assessment is unilateral leg muscle atrophy, He has 2cm muscle atrophy with 4% WPI.”
The difference of opinion between Dr New and Dr Woo as to the degree of WPI suffered by the appellant as a result of the injury on 14 January 2021 gave rise to a medical dispute as that term is used in s 319 of the 1998 Act. Accordingly, a delegate of the President referred the dispute to Dr Shahzad for assessment. It is from his assessment that the appellant brings this appeal.

PRELIMINARY REVIEW

The Appeal Panel conducted a preliminary review of the original medical assessment in the absence of the parties and in accordance with the Procedural Direction PIC7. As a result of that preliminary review, the Appeal Panel determined that there was prima facie error in the Medical Assessor’s assessment of the appellant’s right lower extremity. Accordingly, the Panel concluded that it was appropriate for the worker to undergo a further medical examination by a member of the Panel.

EVIDENCE

The Appeal Panel has before it all the documents that were sent to the Medical Assessor for the original medical assessment and has taken them into account in making this determination.

Medical Assessment Certificate

The parts of the medical certificate given by the Medical Assessor that are relevant to the appeal are set out in the body of this decision.

SUBMISSIONS

Both parties made written submissions. They are not repeated here in full, but have been considered by the Appeal Panel.
While the precise error relied on by the appellant in is not crystal clear, his submission is limited to error in the assessment of the right lower extremity.
The appellant notes that while the Medical Assessor specifically referred to and agreed with the findings and opinion of Dr Woo, he did not refer to the opinion of his qualified orthopaedic surgeon, Dr New. Specifically, he did not refer to the assertion by Dr New that it was appropriate in this case to assess WPI of the right lower extremity by reference to derangement of gait as it more accurately represented the appellant’s “problems” with his gait and his lumbar spine. The appellant argued:
“the MA did not consider the opinion of Dr New with respect to his assessment of WPI at all. This is a demonstrable error on the face of the record.”
The appellant continued that the Medical Assessor had failed to consider “the evidence contained within the opinion of Dr New” [sic] and “by not providing the basis for his reasoning.”
In respect of the application of incorrect criteria, the appellant alleged that the Medical Assessor had failed to use “the method that yields the highest degree of permanent impairment” and failed to utilise a worksheet. The submission continues:
“Not only did the Member not use a worksheet, he identified no other means of assessment other than “range of motion” and in doing so denied the applicant procedural fairness in the assessment of the matter in, what could well have been a higher assessment level.”
The submission continues that:
“The MA has not provide [sic] his reasoning in utilising the ROM assessment when compared to other forms of lower limb assessment per Table 17-AMA5 Guidelines [sic], thus that is an assessment based on incorrect criteria.”
In particular, the appellant asserts that the Medical Assessor did not consider his use of a walking stick and his antalgic gait when assessing impairment.
The respondent submitted that the Medical Assessor’s failure to refer to the methodology employed by Dr New to assess permanent impairment of the right lower extremity did not lead to the conclusion that he did not read or consider Dr New’s report. Indeed, the Medical Assessor referred to Dr New’s report on two occasions in the MAC and “acknowledges that the appellant was examined and assessed by Dr New who allowed 22% WPI in his assessment”. It follows that there was no failure to take into account the available evidence.
In addressing incorrect criteria, the respondent referred to paragraphs 1.23 and 3.2 of the Guidelines and to section 17.2C, page 529, of the Guides. It submitted that given the findings in relation to the use of walking aids and the appellant’s gait, the range of movement method adopted by the Medical Assessor was the most appropriate method.
The respondent submitted that, as the Medical Assessor’s examination was “thorough and reliable,” there was no basis for a re-examination.

Further medical examination

Medical Assessor Home of the Panel re-examined the appellant worker on 5 October 2023 and provided a report to the Panel. Insofar as it is relevant, that report is as follows:
1.   HISTORY RELATING TO THE INJURY
·    Brief history of the incident/onset of symptoms and of subsequent related events, including treatment:
Mr Walton confirms that he sustained an injury on 14 January 2021 whilst installing a level indicator into a pond. He said that after installing the indicator, he stepped back from the edge of the pond to take a photograph, when the mud at the edge of the pond gave way causing both his feet to slip downward. He recalls that his right foot became stuck in the mud and he felt a popping sensation in his distal right thigh.
He telephoned his colleague for assistance. He was subsequently transported to Hawksbury Hospital with pain in his distal right thigh. At the hospital, a diagnosis of a ruptured quadriceps tendon was made. He came under the care of Dr Khatib, orthopaedic surgeon, who performed a primary repair of the quadriceps tendon in the right thigh on the same day. He was discharged from hospital on 16 January 2021.
Following the surgery, his right thigh was immobilised in a range of motion brace for six weeks. He commenced physical therapy. He recalls that he returned to Dr Khatib with further right thigh pain and weakness in May 2021. He underwent further MRI scans which demonstrated dehiscence of the quadriceps repair. Subsequently, Dr Khatib arranged to perform a re-repair of the quadriceps tendon, performed on 7 June 2021 at Nepean Private Hospital.
Following this surgery, he received physical therapy until November 2021. He then continued home based exercise. He returned to an exercise physiologist in early 2022 for further supervised strengthening exercise, which he undertook for a period of three or four months.
There has been no treatment since mid-2022.
He recalls that he developed lower back pain during his period of recovery. He has received advice from the exercise physiologist regarding core strengthening exercise. He continues home based exercise presently.
He does not require analgesia. He takes medications to manage unrelated cardiovascular conditions, for which he underwent stenting in 2012.
·    Present symptoms:
Mr Walton currently reports symptoms of intermittent lower back pain, usually more prominent on the left side, but at other times more prominent on the right. The pain is present a few days per week. There is exacerbation of back pain with prolonged walking and repetitive deep forward bending at the waist, which he avoids. He describes the intensity of pain when present at 5-6/10 on a visual analogue scale (VAS). There are no distal radicular symptoms in the lower extremities. He denies lower limb paraesthesia, numbness or weakness beyond the local weakness in his right thigh.
At the right thigh, there are no distal pain symptoms. He describes intermittent anterior pain and crepitus at the right kneecap. This is particularly prominent with stair climbing and walking on slopes. He is careful to avoid repetitive stair climbing and deep crouching.
He is able to walk without a walking stick, but usually utilises a stick when away from his home, due to symptoms of instability. He walks with the walking stick in his right hand.
He describes an occasional sensation of giving way at the right thigh/knee. There is local knee swelling. He describes difficulty dressing in socks and shoes and does so in a seated position.
·    Details of any previous or subsequent accidents, injuries or condition:
There was a prior fracture to the left femur, suffered in 1985.
There is no prior history of lower limb complaints.
There is no subsequent injury.
·    General health:
He suffered from ischemic heart disease for which he required stenting in 2011 or 2012. He takes medication to manage this.
In 1985, he underwent femoral fixation of a fractured left femur. He made a good functional recovery.
·    Work history including previous work history if relevant:
He was previously working as a quarry manager from 1999.
Currently, he performs work as an environmental officer for a soil company.
In his youth, he worked as a heavy diesel mechanic.
·    Social activities/ADL:
He is married with three children. He is a non-smoker.
At his home, he performs his share of light domestic chores. His wife performs the heavier cleaning tasks. He is able to operate a ride on lawnmower. He performs shopping for odds and ends.
He has curtailed his previous boating activities.
·    Functional capacity and reported tolerances
He is right hand dominant.
He describes a walking tolerance of approximately 100 metres using a stick for support. He says that is able to semi crouch.
There is mild sleep disruption.
He is able to lift and carry moderate weight weighing up to 18kg.
2.   FINDINGS ON PHYSICAL EXAMINATION
Mr Walton presents as a 57 year old, standing at 179cm and weighing 115kg.
Examination of the lumbosacral spine reveals normal spinal curvature. There is no muscle spasm. Lumbar flexion is performed to 2/3 normal range, extension 1/2 normal range, lateral flexion is symmetrical to 3/4 normal range on each side. There is muscle guarding during lumbar extension motion. Straight leg raise is performed symmetrically to 90°. The deep tendon reflexes are symmetrically preserved. There is no distal myotomal weakness or wasting. There is normal sensibility throughout the lower extremities.
On inspection of the right thigh, there is a healed vertical scar, measuring 22cm in length. There is slight atrophic change. There is no contour defect. There are no visible suture marks. There is no tethering. The scar is slightly paler than the surrounding skin.
On measurement, the circumference of the right thigh is 54cm. The circumference of the left thigh is 56.8cm. The circumference of the right calf is 45.3cm and the left calf 45.5cm. There is 2.8cm circumferential wasting of the right thigh.
At the right knee, there is no joint effusion. There is no abnormal joint crepitus. Active motion is measured at 120° flexion, 0° extension. On the left side, there is 130° flexion and 0° extension. There is normal AP and lateral stability at the right knee. There is grade 4 power of resisted right knee extension. There is grade 5 power of resisted knee flexion.
There is a full range of active motion at the right hip.
3.   DETAILS AND DATES OF SPECIAL INVESTIGATIONS
X-ray right knee, dated 19 July 2022. Two cannulated screws are seen within the patella, consistent with previous quadriceps repair.
Ultrasound right knee, dated 19 July 2021. The ultrasound of the quadriceps tendon confirms integrity of the quadriceps tendon repair post-surgery with some early calcific change seen on the quadriceps tendon with hyperaemia thickening and sutures in keeping with post operative changes. Small joint effusion in keeping with post operative synovitis.
X-ray right knee, dated 29 June 2021. Two titanium anchors have been deployed to the superior pole at the base of the patella for quadriceps reconstruction and revision surgery. The screws are well placed. There is no premature osteoarthrosis of the patellofemoral joint or the tibiofemoral joint. On dynamic scan, the quadriceps tendon is seen to move as a single unit cordially ?(10.33), consistent with a successful post-surgical outcome. There is no dehiscence at the previous distraction site.
MRI right knee, dated 7 May 2021. This shows dehiscence/separation of the conjoined quadriceps tendon from the patella.
CT right knee, dated 14 January 2021. Soft tissue oedema along the anterior aspect of the knee with presence of subcutaneous haematoma formation at the anteromedial aspect due to contusion injury. Thickened quadriceps tendon with haematoma formation and markedly attenuated distal insertion site and wavy appearance consistent with complete or near complete rupture of the quadriceps tendon. Possible partial tear of the medial collateral ligament. Minimal joint fluid.
X-ray pelvis, right femur and right knee, dated 14 January 2021. Presence of mild degenerative changes symmetrical at both hips. No definite acute fracture.
Ultrasound of the right quadriceps tendon, dated 14 January 2021. Complete rupture of the distal quadriceps tendon with presence of fluid filled defect and haematoma formation. Partial tear injury at the distal patella tendon and proximal medial collateral ligament.
X-ray and ultrasound right hip, 3 May 2023. Minimal symmetrical osteoarthritic changes at the hips. No right sided gluteal tear of trochanteric bursitis.
CT lumbar spine, dated 3 May 2023. Degenerative changes at the L3/4 level with a shallow osteophytic ridge leading to right mild right foraminal narrowing. At L4/5, shallow annulus thickening. Moderate bilateral facet osteoarthrosis and mild to moderate bilateral foraminal narrowing. At L5/S1, disc height reduction.
4.   SUMMARY
·    summary of injuries and diagnoses:
The claimant suffered a right quadriceps tendon rupture for which he required primary repair. There was a secondary repair due to a re-tear. The secondary repair is now intact on imaging. There is grade 4 weakness of right knee extension consistent with quadriceps weakness.
There is a 2.8cm circumferential wasting of the right thigh.
A mild reduction in the range of right knee flexion compared to the left, reflects quadriceps tendon tightness.
In the lumbar spine, there is a secondary condition, diagnosed as a musculo-ligamentous strain.
·    consistency of presentation
Mr Walton is consistent in his clinical presentation. There are no abnormal clinical signs.
5.   THE FACTS ON WHICH THE ASSESSMENT IS BASED
The facts on which I have based my assessment of whole person impairment are:
I have based my assessment of impairment on the history, examination findings and review of documentation and radiological findings. I have reviewed all the documentation provided.
6.   REASONS FOR ASSESSMENT
a.   My opinion and assessment of whole person impairment
Impairment is determined using the methodology set out in American Medical Association Guides to the Evaluation of Permanent Impairment (5th Edition) and the WorkCover NSW Guides for the Evaluation of Permanent Impairment 4^th Edition.
Lower extremity
Muscle atrophy
Impairment can be determined muscle atrophy.
Using AMA5, modified in the NSW Guides, Table 17-6, page 14.
There is 2.8 cm wasting of the right thigh, consistent with moderate wasting, attracting a 4% WPI rating.
Muscle strength
Manual muscle testing, Section 17.2e directs that manual muscle testing must be concordant with the observed pathological signs and the medical evidence of a quadriceps tendon repair.
This method of assessment is appropriate, noting a history of direct muscle trauma.
I am satisfied that the strength displayed at the current assessment is valid and reliable. There is no apparent pain inhibition operative.
The degree of weakness in the right thigh is consistent with the known pathology and the degree of disuse wasting.
There is a MRC grade 4 power of knee extension, with active movement against gravity with some resistance, but not full resistance.
Weakness of knee extension is grade 4. This attracts a 5% WPI rating using Table 17-8, AMA5, page 532.
The impairment due to weakness cannot be combined with that due to muscle atrophy. The impairment method providing a higher rating is chosen.
Range of motion
The range of motion at the right knee is within normal limits. Using Table 17-10, AMA5, page 537 with a range of flexion of 120° and 0° extension.
Gait
The claimant does not qualify for an assessment of impairment due to gait derangement (17.2c of AMA5).
Table 17-5 directs that impairment due to gait derangement arises due to an antalgic limp with shortened stance phase and documented moderate to advance arthritic change at the hip, knee or ankle with category C requiring in addition part-time use of cane or crutch for distance walking but not usually at home or in the workplace.
In this case, there is no moderately to advanced arthritic change at the hip, knee or ankle.
Further, Section 3.10 of the Workcover Guidelines directs that assessment of gait derangement is only to be used as a method as a last resort. Methods of impairment assessment most fitting the nature of the disorder should always be used in preference.
Further, per Section 3.11, directs that any walking aid used by the subject must be a permanent requirement and not temporary.
In this case, there are very direct methods of assessing impairment in this case.
Further, the claimant does not suffer from documented moderate to advanced arthritic change at the hip, knee or ankle. The use of the gait method is therefore inappropriate on those grounds.
Other methods
I have reviewed the other methods for assessment of impairment in the lower extremity. None apply.

FINDINGS AND REASONS

Section 328(2) of the 1998 Act provides that an appeal is to be by way of review of the original medical assessment, but the review is limited to the grounds of appeal on which the appeal is made. This subsection was considered by Davies J in New South Wales Police Force v Registrar of the Workers Compensation Commission of New South Wales [2013] SC 1792 (11 December 2013). Davies J considered that the form of the words used in s 328(2) of the 1998 Act ‘the grounds of appeal on which the appeal is made’ was intended to convey that the appeal is confined to those particular demonstrable errors identified by a party in its submissions. The Appeal Panel has only considered those grounds specifically raised by the appellant in its application.
In Campbelltown City Council v Vegan [2006] NSWCA 284 (Vegan), the Court of Appeal held that the appeal panel is obliged to give reasons. Where there are disputes of fact it may be necessary to refer to evidence or other material on which findings are based, but the extent to which this is necessary will vary from case to case. Where more than one conclusion is open, it will be necessary to explain why one conclusion is preferred. On the other hand, the reasons need not be extensive or provide a detailed explanation of the criteria applied by the medical professionals in reaching a professional judgement.
The role of the medical appeal panel was considered by the Court of Appeal in Siddik v WorkCover Authority of NSW [2008] NSWCA 116. An appeal by way of review may, depending upon the circumstances, involve either a hearing de novo or a rehearing. Such a flexible model assists the objectives of the legislation. However, in Versace vAustralia Best Tyres & Auto Pty Limited [2016] NSWSC 1540 (2 November 2016) Schmidt J, held that the 1998 Act did not permit the panel to review the determination of the Medical Assessor without first identifying error.
Though the power of review is far ranging it is nonetheless confined to the matters which can be the subject of appeal. Section 327(2) of the 1998 Act restricts those matters to the matters about which the MAC is binding. In considering the submissions of the appellant, it is necessary to bear in mind the nature of the statutory obligation of the Medical Assessor to provide reasons. It is evident from reasoning of the High Court of Australia in Wingfoot Australia Partners Pty Ltd V Kocak[1] that it is only necessary for the MAC to explain the actual path of reasoning of the Medical Assessor in sufficient detail to enable a court or an appeal panel to determine whether there is error in its findings. In Wingfoot it was said that:
“The function of a medical panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise.”
[1] “252 CLR 480.
The reasoning in Wingfoot has been applied to medical assessments under the NSW Workers Compensation legislation: see, for example, El Masri v Woolworths Ltd.[2]
[2] [2014] NSWSC 1344 (26 September 2014).
After conducting a thorough physical examination, utilising a goniometer and inclinometer where appropriate, the Medical Assessor recorded the following findings in respect of the appellant’s right knee:
“He had a 25cm long scar anteriorly which has nicely healed.
On examination, right knee has 105º of flexion. No leg length discrepancy. No extension deficit.
He has no pins, needles, or numbness.
He had stable joints with no laxity. He had pain over the knee joint on the superomedial aspect. He had generalised non-specific pain and had crepitus in the knee.
A 25cm anterior scar tethering the underlying structures.
Range of movement is reduced on the right knee.”
In paragraph 10 of the MAC, the Medical Assessor provided his reasons for assessment. In respect of the right lower extremity, he recorded the following:
“Loss of ROM on right knee, pg 537, Table 17-10 gives 4% WPI.”
In his brief comments regarding other medical opinions, the Medical Assessor stated:
“I am not in disagreement of other opinion. I accept the opinion of Dr Woo, his examination findings and impairment rating.”
While the Medical Assessor referred to the report of Dr New on two occasions in his MAC, he did not address Dr New’s contention that the impairment of the appellant’s right lower extremity was best addressed utilising Derangement of Gait in accordance with section 17.2c of AMA5.
It is evident from the reasoning in Wingfoot, that it is unnecessary for a Medical Assessor to “opine on the correctness of other medical opinions” on the question that has been referred to him for assessment. On the other hand, the case law establishes that failure to respond to “a substantial, clearly articulated argument relying upon established facts” is a denial of natural justice: see Allianz Australia Insurance Limited v Cervantes,[3] where Basten JA addressed the legal obligation of administrative decisionmakers to take particular evidence into account.
[3] (2012) 61 MVR 443 at [24].
In this case, the argument that the appellant should be assessed in accordance with the method prescribed for gait derangement was an essential ingredient of the claim which the worker made for permanent impairment of the right lower extremity. There was evidence before the Medical Assessor that he walked “with a limping gait” and that he utilised a stick when walking long distances.
While the matter is not entirely free from doubt, the panel concluded that failure to address the substance of the appellant’s case in respect of impairment of his lower extremity constituted demonstrable error in the MAC. A party is entitled to have the substance of the case he makes considered by a decision maker. While the Panel did not find the opinion of Dr New persuasive, it concluded that in order to afford procedural fairness to the appellant, he should be reassessed by a member of the Panel in respect of his right lower extremity (knee).
Following Medical Assessor Home’s re-examination of the appellant, the panel reconvened to consider his findings and assessment in respect of the assessment of the appellant’s right lower extremity (knee). The panel concluded that the methodology adopted by Dr New for assessing the right knee was inconsistent with AMA 5 and the Guidelines. As Medical Assessor Home stated in his report to the panel, assessment by reference to the gait derangement is a method of last resort. Chapter 3.10 of the Guidelines states:
“Assessment of gait derangement is only to be used as a method of last resort. Methods of impairment assessment most fitting the nature of the disorder should always be used in preference. If gait derangement (AMA5 section 17.2c, p 529) is used, it cannot be combined with any other evaluation of the lower extremity section of AMA5.”
In the circumstances of this case, there are plainly methods of impairment assessment more fitting the nature of the disorder to be assessed.
After considering Medical Assessor Home’s findings in the context of all of the evidence in the case, the panel concluded that it should adopt his assessment of impairment of the right lower extremity by utilising Table 17-8, which provides the criteria for measuring muscle function of the lower extremity. This approach gives the appellant a higher WPI then the other permissible approaches.
It follows that the panel determines that the appellant suffers 5% WPI of his right upper extremity as a result of the injury on 14 January 2021. To this must be added 6% WPI in respect of the lumbar spine, and 2% for scarring. These percentages were certified by the Medical Assessor and are not the subject of this appeal. The panel, therefore, concludes that the appellant suffers 13% WPI as a result of the injury of 14 January 2021.
For these reasons, the Appeal Panel has determined that the MAC issued on 18 May 2023 should be revoked, and a new MAC should be issued. The new certificate is attached to this statement of reasons.

PERSONAL INJURY COMMISSION

APPEAL PANEL

MEDICAL ASSESSMENT CERTIFICATE

Injuries received after 1 January 2002

Matter number:	W2437/23
Applicant:	Michael Walton
Respondent:	Aus-10 Rhyolite 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 Farhan Shahzad of 18 May 2023 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 AMA 5 Guides	% WPI	Proportion of permanent impairment due to pre-existing injury, abnormality or condition	Sub-total/s % WPI (after any deductions in column 6)
1. Lumbar spine	14/1/21	Chapter 4.34-4.35	Page 384, Section 15.4, Table 15.3	6%	0%	6%
2. Right Lower Extremity	14/1/21	Table17.8, page532	5%	0%	5%
3.Scarring	14/1/21	TEMSKI Table14.1	2%	0%	2%
Total % WPI (the Combined Table values of all sub-totals)					13%

The above assessment is made in accordance with the SIRA NSW Guidelines for the Evaluation of Permanent Impairment for injuries received after 1 January 2002.

[2023] NSWPICMP 513

13 October 2023