Tattersall v Brewarrina Shire Council

DETERMINATION OF APPEAL PANEL
CITATION:	Tattersall v Brewarrina Shire Council [2021] NSWPICMP 78
APPELLANT:	Alan Tattersall
RESPONDENT:	Brewarrina Shire Council
APPEAL PANEL:	Member Carolyn Rimmer Dr James Bodel Dr Mark Burns
DATE OF DECISION:	28 May 2021
CATCHWORDS:	WORKERS COMPENSATION- Whether the Medical Assessor should have assessed the lower extremities (knees) under Table 17-31 of AMA5 which refers to arthritis impairments; Held- that there was no radiological support required to make such an assessment and the requisite radiology measuring cartilage intervals was not available; MAC confirmed.

STATEMENT OF REASONS FOR DECISION OF THE APPEAL PANEL IN RELATION TO A MEDICAL DISPUTE

BACKGROUND TO THE APPLICATION TO APPEAL

On 25 February 2021 Alan Tattersall (the appellant) lodged an Application to Appeal Against the Decision of Approved Medical Specialist. The medical dispute was assessed by Dr Tim Anderson, an Approved Medical Specialist (since 1 March 2021 with the commencement of the Personal Injury Commission Act 2020, known as a Medical Assessor (MA)), who issued a Medical Assessment Certificate (MAC) on 1 February 2021.
The respondent to the appeal is Brewarrina Shire Council (the respondent).
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.
The WorkCover Medical Assessment Guidelines 2006 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 the WorkCover Medical Assessment Guidelines 2006.
The assessment of permanent impairment is conducted in accordance with the NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, 4^th ed 1 April 2016 reissued 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

In these proceedings, the appellant is claiming lump sum compensation in respect of an injury to the left lower extremity (knee), and right lower extremity (knee) deemed to have occurred on 8 March 2018.
In a Further Amended Direction dated 10 June 2020 Arbitrator McDonald remitted the matter to the Registrar to be placed in the Approved Medical Specialist pending list. Arbitrator McDonald ordered:
“2. The referral to the AMS should read as follows:
Body parts: Left lower extremity (knee)
Right lower extremity (knee)
Date of injury: Deemed date of injury 8 March 2018, as a result of the nature and
conditions of employment from 1976 to 8 March 2018, including
injuries
a) to the right knee on 4 November 1984 and 8 March 2018, and
b) to the left knee on 4 November 1984 and 22 September 2016.
Method of assessment: Whole person impairment.
3. The referral should also read:
Concurrently with the assessment of whole person impairment, the AMS is requested to determine, as a general medical dispute, the percentage of whole person impairment that results from
a) the injury on 4 November 1984, and
b) the nature and conditions of employment from 1976 to 1 January 2002.”
In the Referral for Assessment of Permanent Impairment to Approved Medical Specialist dated 23 December 2020, the matter was referred to the MA, Dr Tim Anderson, for assessment of whole person impairment (WPI) of the left lower extremity (knee) and right lower extremity (knee) with the deemed date of the injury being 8 March 2018 as a result of the nature and conditions of employment from 1976 to 8 March 2018 including injuries to the left knee on 4 November 1984 and 8 March 2018 and injuries to the right knee on 4 November 1984 and 22 September 2016.
The MA examined the respondent on 27 January 2021. He assessed 4% WPI of the left lower extremity and 4% WPI of the right lower extremity. Therefore, the total assessment was 8% WPI in respect of the injury deemed to have occurred on 8 March 2018.

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 WorkCover Medical Assessment Guidelines 2006.
As a result of that preliminary review, the Appeal Panel determined that it was not necessary for the worker to undergo a further medical examination because there was sufficient evidence on which to make a determination.

EVIDENCE

Documentary evidence

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

Medical Assessment Certificate

The parts of the medical certificates given by the MA that are relevant to the appeal are set out, where relevant, in the body of this decision.

SUBMISSIONS

Both parties made written submissions. They are not repeated in full, but have been considered by the Appeal Panel.
The applicant’s submissions included the following:
(a)    The assessment methodology is set out in Chapter 3 of the Guidelines at page 13 and refers to the various forms of evaluation set out in AMA5, pp 528 to 554. At 3.5 of the Guidelines, the assessor is directed to use the evaluation giving the highest evaluation rating:
“3.3. In the assessment process, the evaluation giving the highest
impairment rating is selected…”
(b)    The evaluation which gave the highest rating is found at para 17.2h of AMA5 which includes Table 17-31, which refers to Arthritis Impairments Based on
Roentgengraphically Determined Cartilage Intervals.
(c)    The MA assessed the appellant but did not use this preferred and required method of evaluation at Table 17-31, preferring to incorrectly apply Range of Movement.
(d)    The fact that AMA5 17.2h gives a higher rating was demonstrated by the report and assessment of Dr Hopcroft of 27 March 2019.
(e)    Dr Niranjan Ganeshan prepared an MRI report dated 4 September 2018.
Dr Ganeshan reports the existence of Grade IV chondrosis in the medial tibial plateau and Grade IV chondrosis of the medical femoral trochlea. Dr Ganeshan also reported the existence of Grade IV chondomalacia, which is the most severe grade of this condition. This condition indicated exposure of the bone with a significant portion of cartilage having deteriorated. These conditions allowed for allow for bone on bone contact to likely to occur in the knee, as confirmed by
Dr Hopcroft.
(f)    Grade IV chondrosis and Grade IV chondomalacia are conditions whereby cartilage has worn away completely, leaving bone exposed. The MRI report of
Dr Ganesha dated 4 September 2018 demonstrated that the chondrosis and chondomalacia in the appellant’s knee were widespread.
(g)    The need for joint replacement or major reconstruction usually corresponds with complete loss of articular surface i.e. joint space (see third paragraph of AMA5 17.2h). Dr Hopcroft noted that the appellant will require a right knee arthroplasty. Dr Stephen Ruff, the appellant’s treating orthopaedic surgeon, has advised that the appellant should not rush into knee joint replacements but the MA noted that ‘these will ultimately be needed.’
(h)    The MA accepted the opinion of Dr Stephen Ruff, in so far as it relates to the eventual need for knee joint replacements. By accepting the opinion of Dr Ruff it can be inferred that the MA found that the appellant had sustained a complete loss of articular surface. This contradicted the method of evaluation used by the MA and confirmed that the MA should have in fact used AMA5 17.2h and Table 17-31.
(i)    The assessment was made on the basis of incorrect criteria. A demonstrable error arose from the application of the incorrect criteria, outlined above. The MA’s error was demonstrated by:
(i)his dismissal of the opinion of Dr Hopcroft;
(ii)failure to properly consider and therefore dismiss the MRI report of
Dr Ganeshan dated 4 September 2018; and
(iii)the inherently contradictory approach within MAC in accepting the appellant has advanced osteoarthritis as opined by Dr Hopcroft, and by also by implication, in accepting the opinion of Dr Ruff which indicated that the appellant has a complete loss of articular surface warranting surgery.
(j)    These errors identified in paragraph 20, led to the MA failing to apply the correct criteria to assess the appellant’s impairment.
(k)    The appellant acknowledges that the MA’s task is not to decide between the competing assessments of the parties, but to apply his own clinical judgement. However, the MA' s rejection of Dr Hopcroft’s approach demonstrated his error and that the AMS’s conclusion was not based on radiological support.
(l)    The MA did not engage with the fact that Dr Hopcroft referred to radiology
identifying Grade IV chondrosis and Grade IV chondomalacia. However the MA referred to the condition at page 4 of the MAC as Grade IV osteoarthritis of the right knee joint. This in turn qualified for the bone on bone criterion contained in Table 17-31 at p.544 of AMA 5 and therefore, the MAC contained a demonstrable error.
(m)     The MAC should be set aside and a fresh certificate be issued by the Medical Appeal Panel.
The respondent’s submissions include the following:
(a)    The assessment of the MA comprised 4% WPI by reference to restriction of movement of the left lower extremity (knee) and 4% WPI by reference to restriction of movement of the right lower extremity (knee).
(b)    The appellant submitted that the MA failed to apply the appropriate methodology required by of him as set out in paragraph 3.5 of the Guidelines, which direct the assessor to use the evaluation giving the highest rating.
(c)    The MA identified in his reasoning at 10(b) on page 5 of the MAC that the following features could have given rise to a WPI:
(i)Muscle wasting right thigh;
(ii) Muscle wasting left calf;
(iii) Chondromalacia patellae right knee, and
(iv) Reduced range of movement both knees.
(d)    Having identified each of the potential methods, the MA then identified that the range of movement method resulted in the greatest impairment.
(e)    The appellant asserted that the highest rating is found at 17.2h of AMA5, being the method of assessment for arthritis, as applied by Dr Hopcroft.
(f)    At paragraph 10(c) on page 6 of the MAC, the MA provided his reasons for rejecting Dr Hopcroft’s assessment of 20% WPI for osteoarthritis, namely, that there was no radiological support with the information required to make such an assessment. This reasoning also provided the basis for declining to apply the methodology found in 17.2h, namely that the requisite radiology measuring cartilage intervals was not available.
(g)    Chapter 17.2h in AMA5 provides the method of assessing WPI arising from arthritis. Table 17-31 on page 544 of AMA5 sets out the WPI assigned for arthritis impairments based on roentgenographically determined cartilage intervals. For the knee, the Table provides a WPI percentage depending on the measured cartilage interval (3mm, 2mm, 1mm and 0 mm).
(h)    Clause 3.20 in the Guidelines provides that cartilage loss can be measured by properly aligned plain x-ray, or by direct vision (arthroscopy) ‘but impairment can only be assessed according to the radiologically determined cartilage loss intervals shown in AMA 5 Table 17-31 (p544).’ It goes on to say at Clause 3.23 that the ‘accurate radiograph assessment of joints always requires at least two views.’ Therefore, in the absence of appropriate imaging with the requisite measurements, the method of assessment in chapter 17.2h was not available.
(i)    Whilst the applicant has had MRI and x-ray imaging of his knees, the reports did not include reference to any measurement of the cartilage intervals and therefore it was not open to Dr Hopcroft to adopt that method.
(j)    The appellant also relied on the MRI report of Dr Ganeshan dated 4 September 2018, in particular, the existence of Grade IV chondrosis in the medial tibial plateau and patellofemoral chondrosis, to demonstrate that the cartilage was completely worn away and bone exposed, thereby allowing for bone on bone contact to occur in the knee. The MA specifically addressed this at paragraph 10(c) on page 6, where he stated ‘… there does not appear to be appropriate radiological support with specific identification which would confirm this …’ In other words, it was not sufficient for Dr Hopcroft to have adopted this method of assessment in the absence of the necessary radiological support.
(k)    The findings on the MRI were not sufficient for an assessment pursuant to Chapter 17.2h because there was no measurement of the cartilage interval or joint space as specifically required to apply to Table 17-31. The MA was correct in saying that there was not appropriate radiological support.
(l)    The MA’s reasons for rejecting the assessment of Dr Hopcroft and declining to use the method found in 17.2h of AMA5 were adequate and correct, and did not represent application of incorrect criteria.
(m)     The MA’s identification of the various methods of assessment available, and his rejection of the method adopted by Dr Hopcroft, was supported by the evidence and his findings, and reflected the correct application of AMA5 and the Guidelines.
(n)    To the extent that the applicant submits that there was a demonstrable error by reason of the MA dismissing the report of Dr Hopcroft and failing to properly consider the MRI report of Dr Ganeshan, the respondent relies upon its submissions set out above. The MA specifically addressed the report of
Dr Hopcroft and noted his reasons for rejecting his method of assessment, specifically being that the radiological support required to calculate WPI pursuant to Table 17-31 was lacking.
(o)    The appellant’s suggestion that there was a demonstrable error by reason of the ‘inherently contradictory’ approach in accepting that the applicant has advanced osteoarthritis as opined by Dr Hopcroft, and by implication in accepting the opinion of Dr Ruff as to the complete loss of articular surface warranting surgery in the future, was difficult to understand. There was nothing ‘inherently contradictory’ in the AMS noting and accepting the degenerative changes in the applicant’s knees and applying the correct methodology for assessment as required by the AMA5 and Guidelines.
(p)    As such, it cannot be substantiated that the MAC contains any demonstrable errors.
(q)    The appeal should be dismissed.

FINDINGS AND REASONS

The procedures on appeal are contained in s 328 of the 1998 Act. The 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.
In Campbelltown City Council v Vegan [2006] NSWCA 284 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 the case of Siddik v WorkCover Authority of NSW [2008] NSWCA 116 (Siddik). The Court held that while prima facie the Appeal Panel is confined to the grounds the Registrar has let through the gateway, it can consider other grounds capable of coming within one or other of the section 327(3) heads, if it gives the parties an opportunity to be heard. 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.
Section 327(2) was amended with the effect that while the appeal was to be by way of review, all appeals as at 1 February 2011 were limited to the ground(s) upon which the appeal was made. In New South Wales Police Force v Registrar of the Workers Compensation Commission of New South Wales [2013] SC 1792 Davies J considered that the form of the words used in s 328(2) of the 1998 Act being, ‘the grounds of appeal on which the appeal is made’ was intended to mean that the appeal is confined to those particular demonstrable errors identified by a party in its submissions.
In this matter, the delegate determined that there is an arguable case of error under s 327(3) of the 1998 Act in relation to the MA’s assessment of permanent impairment of the left knee and right knee.

The MAC

Under “Findings on Physical Examination” the MA noted:
“Lower Limbs. He walked very cautiously with a wide-based gait. He was unable to stand on his heels and toes or to squat.
The legs were equivalent in length. The right thigh was 1cm less in circumference than the left. The left calf was 0.5cm less.
He wore braces on each knee which were removed for this assessment.
No significant features were identified with the hips or the ankles.
With the knees he had full extension at 0°. On the right side, flexion stopped at 90°. On the left, it stopped at 105°.
There was no knee joint swelling. On the right side there was retro-patellar tenderness but not on the left. There was a lot of joint-line tenderness both medially and laterally with both knees.
Neurologically there were no significant issues.”
Under “Details and Dates of Special Investigations”, the MA referred to an MRI Scan of the right knee dated 4 September 2018 noting that there were degenerative changes throughout. The MA also referred to plain x-ray knees dated 3 May 2019 and noted: “Degenerative changes, more severe in the right knee than the left, mostly at the patella-femoral articulation”.
Under “Summary” the MA wrote:
“Mr Tattersall gives a history of moderate impact injury to both of his knees which occurred as long ago as 1984. There is a suggestion that he may have experienced
fractured patellae although it would seem unlikely that there were actually fractures, since he was still able to walk around (albeit with difficulty) and could continue with his plant driving occupation. Nevertheless, this is likely to have resulted in chondromalacia patellae on each side. As the years went by, there has been accelerated degenerative change in both of his knees. This has been further enhanced by other aggravational factors which have occurred in the intervening period of time. The most recent of these was in March 2018 when he caught his right foot on the lower edge of a dog trap and wrenched the knee further.
His clinical management has remained conservative with cortisone injections. As the years have gone by, the condition has progressively deteriorated. It has been suggested that he will need knee joint replacements, but that he should hold off for as long as possible.”
Under “Reasons for Assessment ” the MA wrote:
“a. My opinion and assessment of whole person impairment:
Left lower extremity (knee) 4%
Right lower extremity (knee) 4%
b. An explanation of my calculations:
The following features were identified which could give rise to whole person impairment:
Muscle wasting right thigh 1cm
Muscle wasting left calf 0.5cm
Chondromalacia patellae right knee
Reduced range of movement of both knees
Out of these possibilities, the reduced range of movement as identified in AMA 5 Page 537, Table 17-10 results in 4% WPI on each side (range of movement of flexion between 80° and 110°). This would give the greatest WPI and is therefore selected.”

The MA, in commenting on other medical opinion, wrote:
“There is only one other report in which whole person impairment has been calculated and that was by Specialist Orthopaedic Surgeon, Dr Alan Hopcroft in his reports of 27/03/19 supported by 09/05/19. There is a very large whole person impairment of 20% of the right knee which depends on the concept of “bone on bone” degenerative change. As well as this, there is 2% on each side for chondromalacia patellae. With great respect, there does not appear to be appropriate radiological support with specific identification which would confirm this very large whole person impairment.”
The Appeal Panel reviewed the history recorded by the MA, his findings on examination, and the reasons for his conclusions as well as the evidence referred to above. The Appeal Panel accepts the findings on examination that the MA made in the MAC.
The Guidelines at 1.1 provide that:
“The Guidelines adopt the 5th edition of the American Medical Association’s Guides to the Evaluation of Permanent Impairment (AMA5) in most cases. Where there is any deviation, the difference is defined in the Guidelines and the procedures detailed in each section are to prevail.”
The Guidelines at Paragraph 3.3 provide that the “most specific method of impairment assessment should be used.”
The Guidelines at Paragraph 3.20 provides:
“The presence of osteoarthritis is defined as cartilage loss. Cartilage loss can be measured by properly aligned plain X-ray, or by direct vision (arthroscopy), but impairment can only be assessed according to the radiologically determined cartilage loss intervals shown in AMA5 Table 17-31 (p 544). When assessing impairment of the knee joint, which has three compartments, only the compartment with the major impairment is used in the assessment. That is, measured impairments in the different compartments cannot be added or combined.”
The Guidelines at Paragraph 3.23 provides:
“The accurate radiographic assessment of joints always requires at least two views. In some cases, further supplementary views will optimise the detection of joint space narrowing or the secondary signs of osteoarthritis.
…
Knee – Tibio-femoral joint: The best view for assessment of cartilage loss in the knee is usually the erect intercondylar projection, as this profiles and stresses the major weight-bearing area of the joint, which lies posterior to the centre of the long axis. The ideal X-ray is a posteroanterior view, with the patient standing, knees slightly flexed, and the X-ray beam angled parallel to the tibial plateau (Rosenberg view). Both knees can be readily assessed with the one exposure. It should be recognised that joint space narrowing in the knee does not necessarily equate with articular cartilage loss, as deficiency or displacement of the menisci can also have this effect. Secondary features, such as subchondral bone change and past surgical history, must also be taken into account.
Knee – Patello-femoral joint: This should be assessed in the ‘skyline’view, again preferably with the other side for comparison. The X-ray should be taken with 30 degrees of knee flexion to ensure that the patella is load-bearing and has engaged the articular surface femoral groove.”

Section 17.2h of AMA 5 at page 544, under “Arthritis” provides:
“Roentgenographic grading systems for inflammatory and degenerative
arthritis are well established and widely used for treatment decisions and
scientific investigation. For most individuals, roentgenographic grading is
more objective and valid method for assigning impairment estimates than
physical findings, such as range of motion of joint crepitation. While there ae [sic] some individuals with arthritis for whom loss of motion is the principal impairment, most people are impaired more by pain and sometimes weakness, but they still can maintain functional ranges of motion, at least in the early stages of the process. Range of motion techniques are therefore limited value for estimated impairment secondary to arthritis…
The best roentgenographic indicator of disease stage and impairment for a person with arthritis is the cartilage interval or joint space. The hallmark of all types of arthritis is thinning of the articular cartilage; this correlates well with disease progression.
…
The need for joint replacement or major reconstruction usually correlates well with complete loss of articular surface (joint space). The impairment estimates in a person with arthritis (Table 17-31) are based on a standard x-ray taken with the individual standing if possible. The ideal film-to-camera distance is 90cm(36In), and the beam should be at the level of and parallel to the joint surface…
In the case of the knee, the joint must be in neutral flexion-extension position (0 degree) to evaluate the x-rays.”
The Appeal Panel notes that roentgenography is x-ray photography and s 17.2h of AMA5 provides for a grading system through the use of x-rays for assigning impairment estimates in a person with arthritis.
The applicant submitted that the MA erred or made the assessment on the basis of incorrect criteria because he did not use the method of evaluation that gave the highest rating, that is, para 17.2h of AMA5 which includes Table 17-31, which refers to Arthritis Impairments.
The Appeal Panel noted that the only x-rays available were the x-rays of 3 May 2019. The
x-ray report of 3 March 2019 did not state whether the x-rays were weight-bearing or non-weight bearing and there was no reference to whether the x-ray was a skyline view of the patella.
Dr Gutmann in the x-ray report dated 3 May 2019 wrote:
“CLINICAL HISTORY:
Grade 4 OA (osteoarthritis) of right and chondromalacia patella on the left knee.
FINDINGS:
The right medial tibiofemoral compartment appears slightly narrowed. There is slight to moderate osteophyte formation at the margins of the right tibiofemoral compartment especially medially, hypertrophy of the tibial intercondylar spine.
Slight left tibial intercondylar spinal hypertrophy is noted. There is slight
osteophyte formation at the margins of the right patellofemoral joint. Minimal
similar change is seen on the left.
There is a small right joint effusion.
CONCLUSION:
There is slight right medial meniscal and cartilage damage. There is slight to
moderate degenerative change at the right tibiofemoral and patellofemoral joints and to a lesser extent the left tibiofemoral.”
The Appeal Panel noted that Dr Gutmann reported that stated that right medial tibiofemoral compartment appeared “slightly narrowed”, and such a finding did not suggest that there was bone on bone contact in the right knee compartment.
While the appellant submitted that the MA should have evaluated impairment under paragraph 17.2h and Table 17-31 of AMA5, that method of assessment of impairment cannot be utilised unless x-rays are available that meet the requirements set out in the Guidelines at 3.20 and 3.23 and in AMA5 at paragraph 17.2h and Table 17-31. The x-ray report of 3 May 2019 does not meet the requirements in the Guidelines and AMA 5 and does not provide a basis for assessing and measuring the cartilage interval or joint space which is required for an assessment under Table 17-31 of AMA5. The Guidelines and AMA5 do not allow for the use of an MRI scan as an alternative to x-rays that meet the requirements set out in the Guidelines at 3.20 and 3.23 and in AMA5 at paragraph 17.2h and Table 17-31.
Since the x-rays provided were not suitable for assessment of arthritis under the Guidelines at 3.20 and 3.23 and in AMA5 at paragraph 17.2h and Table 17-31, the method of assessment, range of motion (ROM) used by the MA was appropriate in the circumstances.
The applicant submitted that the MA did not engage with the fact that Dr Hopcroft referred to radiology identifying Grade IV chondrosis and Grade IV chondomalacia but referred to the condition at p.4 of the MAC as Grade IV osteoarthritis of the right knee joint.
Firstly, the Appeal Panel could not see a reference at page 4 of the MAC by the MA to the appellant having Grade IV osteoarthritis of the right knee joint. Secondly, the MA clearly engaged with the opinions and method of assessment used by Dr Hopcroft. The MA referred to Dr Hopcroft’s assessment in his comments in the MAC and expressed the view, with which the Appeal Panel agrees, that there was not the appropriate radiological support with specific identification which would confirm Dr Hopcroft’s assessment of whole person impairment. Further, it cannot be inferred from the MAC, that the MA accepted that the appellant had sustained a complete loss of articular surface and even if the Appeal Panel accepted that argument, it was still necessary for the assessment to be based on x-ryas that met the requirements set out in the Guidelines at 3.20 and 3.23 and in AMA5 at paragraph 17.2h and Table 17-31.
Dr Hopcroft in his report dated 27 March 2019 wrote:
“By way of reference to the Guides to the Evaluation of Permanent Impairment AMA Edition 5 reference is made to Page 544, Table 17-31 (including the footnote of that table) where, with Grade 4 osteoarthritis of his right knee joint and bone-on-bone reflecting a cartilage interval of zero millimetres, he has a whole person impairment of 20%.
With significant chondromalacia patellae of the right knee he has an additional whole person impairment of 2%.
On the left knee he has a whole person impairment from chondromalacia patellae of 2%.
I am awaiting the plain x-ray of his left knee joint to make an assessment of whole person impairment arising from the x-ray-determined cartilage interval narrowing.”
Dr Hopcroft was aware of the requirement to use a plain x-ray to make an assessment of WPI from x-ray determined cartilage interval narrowing. In a supplementary report dated 9 May 2019, Dr Hopcroft advised that the appellant had proceeded to an x-ray of both knees on 3 May 2019. He wrote: “This investigation suggests no reduction in the "x-ray determined cartilage interval" which may reflect an underlying meniscal cartilage tear.
The Appeal Panel also noted that Dr Anthony Smith in his report dated 23 September 2019 wrote:
“Dr Hopcroft’s assessment is based on the statement that there is bone on bone in an MRI report. That is not the preferred method of making that impairment assessment. The actual x-rays that he ordered, and which were undertaken in 2019, should be viewed and the actual cartilage interval loss be measured in millimetres. An accurate assessment can then be arrived at and there would be no need for an additional impairment, as he did with his second letter.”
In conclusion, the MA clearly considered the various methods of assessment of impairment of the knees and concluded that the appropriate impairment modality assessment then was loss of range of motion in the knees. The Appeal Panel considered that this method of impairment assessment was appropriate given the clinical findings and investigations. The Appeal Panel concluded that there was no demonstrable error in the MAC and that there had been no incorrect application of relevant assessment criteria.

For these reasons, the Appeal Panel has determined that the MAC issued on 5 January 2021 by the MA should be confirmed.

[2021] NSWPICMP 78

28 May 2021