REVIEW PANEL ASSESSMENT OF DEGREE OF PERMANENT IMPAIRMENT

Certificate issued under s 7.26(7) of the Motor Accident Injuries Act 2017

1. The Review Panel confirms the certificate of Medical Assessor Mohammed Assem dated 27 November 2024.

1. On 11 February 2022, at approximately 9.15am, Thomas Michael Ahearn (the claimant) was involved in a head-on motor vehicle accident on Lovedale Road in the Hunter Valley region. He was driving a 2016 Mitsubishi ASX-SUV wagon. As he navigated the curve while travelling southbound, at an estimated speed of 75 kmph, he noticed a Ford Laser travelling northbound. It appeared to lose control on the bend and veered into the claimant's lane.
2. The airbags in the claimant's vehicle deployed immediately upon impact. Steam began to emanate from the radiator, initially mistaken by the claimant for smoke. The seatbelt restrained him forcefully, causing pain over his sternum. He also experienced pain in his neck, right shin with swelling, left hip and ankle. He did not lose consciousness and described the impact as a "jolt".
3. Upon attempting to exit the vehicle, the claimant found the driver's door difficult to open, due to damage to the chassis, which had been bent in the collision. A bystander, who witnessed the accident, forced the driver's door open and assisted the claimant in exiting the vehicle. The bystander encouraged him to move away, concerned about a potential fire, and helped him sit on the roadside until emergency services arrived.
4. The offending driver, a young male, was semi-conscious and trapped in his vehicle. Emergency services attended the scene. An off-duty paramedic provided initial assistance to both drivers. The claimant was transported by ambulance to John Hunter Hospital for treatment.
5. The claimant remained in hospital for three days. The hospital discharge documentation confirmed a fractured sternum, which the claimant states was the only definitive diagnosis made at that time. Bruising on his right shin and minor injuries to both legs were evident. The claimant attended his local medical officer, Dr Sarki, a week later, complaining of sternal pain and neck stiffness. No complaints of knee pain were documented during that consultation.
6. On 8 April 2022, the claimant submitted an Application for Personal Injury Benefits, detailing injuries including chest pain, right shin pain, left ankle discomfort, left hip pain, left rib pain and dizziness. Knee injuries were not listed in the application.
7. QBE Insurance (Australia) Limited (the insurer) indemnifies the owner and/or the driver of the at-fault vehicle for liability to pay to the claimant any damages and/or statutory benefits under the Motor Accident Injuries Act 2017 (the Act). The insurer admitted liability for the claim but declined to concede that the degree of whole person impairment, arising from injuries caused by the motor accident, exceeded the 10% WPI threshold.

1. As there is a dispute between the parties about the degree of permanent impairment under Schedule 2, cl 2(a) of the Act, the claimant was referred to Medical Assessor Mohammed Assem for assessment of the following injuries:

(a) cervical spine - severe aggravation of cervical spondylosis;

(b) left knee - aggravation of previous degenerative changes;

(c) right knee - aggravation of previous degenerative changes, and

(d) sternum - fracture.

1. Medical Assessor Assem certified on 27 November 2024 as follows:

The following injuries caused by the motor accident give rise to a permanent impairment of 5% and IS NOT GREATER THAN 10%:

(a) Cervical spine - soft tissue injury, aggravation of pre-existing cervical spondylosis

Medical Assessor Assem made no adjustment for pre-existing/subsequent causes, apportionment or treatment effects.

1. Medical Assessor Assem found that the following injuries WERE NOT caused by the motor accident:

Medical Assessor Assem found advanced osteoarthritis in both knees not causally related to the accident. He did not so certify.

1. Medical Assessor Assem found the following injury caused by the motor accident has RESOLVED:

1. The claimant sought a review of Medical Assessor Assem's certificate, on the grounds that the medical assessment was incorrect, within the meaning of s 7.26 of the Act, in a number of material respects. The claimant relied on the particulars set out in the application and supporting documentation.
2. The claimant brought the application within the time prescribed by s 7.26(10)(a) of the Act and cl 34 of Procedural Direction PIC 7 (28 days).
3. The claimant submitted as follows:

(a) the medical assessment has not assessed the injuries referred. The medical assessment was incorrect in a material respect concerning the severity of the collision and the onset of symptoms above both knees. The assessment appears to have proceeded at odds with the contents of cl 6.6 of the Motor Accident Guidelines (Version 9.2) (Guidelines). The medical assessment appears not to have engaged the contents of cl 6.7 of the Guidelines;

(b) Medical Assessor Assem misapprehended the violence of the collision. The assessment certificate at page 4.9 asserts the claimant "described the impact as a jolt", which is suggestive of a minor collision. The claimant submitted that, in fact, it was a high-speed head-on collision on a country road where both vehicles were travelling at speeds in excess of 75 kmph, with a net collision momentum of more than 150 kmph;

(c) Medical Assessor Assem gave a diagnosis for both knees of advanced osteoarthritis, not causally related to the accident. He did not address the issue of aggravation of previous degenerative changes in both knees, which were conditions referred for assessment;

(d) in respect of each knee, the assessment negates causation on the stated grounds "..,, absence of contemporaneous documentation of trauma, coupled with the delayed onset of symptoms; and ..... the absence of earlier complaints or findings in clinical records";

(e) in response, the claimant notes that his driver's seat deformed and pushed forward with the airbags, including those under the dashboard. The claimant says both of his knees were struck by the below dashboard airbag. The right knee was X-rayed at John Hunter Hospital. The claimant says there were reasons to explain any delay in complaint about the knees;

(f) the claimant submits that Medical Assessor Assem appears to have mistaken the referral as a claim of the collision having caused the osteoarthritis in both knees rather than aggravating such existing conditions;

(g) the claimant further submits that:

"In circumstances of pathological insults to each leg above and below the knees, it is reasonable to consider that the vulnerable intermediate articular joints, namely the knees, would have been more likely they are not subject to rearrangement to some degree."

Various decided cases are cited in support of that proposition, and

(h) the claimant finally submits that Medical Assessor Assem did not assess the injuries referred in relation to the knees, contrary to the Guidelines and relevant case law.

1. The claimant's review application was opposed by the insurer on various grounds as follows:

(a) The insurer disputes the claimant's allegation that the Medical Assessor did not consider the question of aggravation with respect to each knee. It notes that the claimant did not list injuries to his knees in his Application for Personal Injury Benefits and that his alleged knee complaints were not initially reported to his treating doctors. The insurer notes expert medical opinion to the effect that the claimant's bilateral knee complaints were attributable to pre-existing osteoarthritis with no evidence of direct trauma related to the knees during the accident. The insurer notes that Medical Assessor Assem referred to that evidence and took it into account in making his clinical findings.

(b) The insurer submitted that Medical Assessor Assem did not misapprehend the violence of the collision and thoroughly considered all the available evidence to him in its entirety.

(c) The insurer disputed the claimant's allegation that Medical Assessor Assem overlooked his patent pathology. The insurer notes that Medical Assessor Assem records the claimant's first reported knee pain 17 months after the subject accident. It disputes that the claimant's recovery from his sternum fracture would be a reasonable circumstances to explain any delay in complaints about bilateral knee symptoms. The insurer submits that Medical Assessor Assem established there is no causal link between the claimant's knee complaints and the subject accident. He found that the claimant's knee symptoms are associated with "degenerative and advanced osteoarthritis" that has not been aggravated as a result of the accident.

1. The claimant made short submissions in reply to the insurer's submission. Those further submissions briefly are summarised as follows:

(a) the insurer's submissions do not address the fact that the medical assessment failed to assess the referred injuries being aggravation of previous degenerative changes in both knees;

(b) the assessment restricts itself to whether the osteoarthritis evident about both knees was caused by the subject collision. The referred question of aggravation is not assessed. The insurer's submissions leave that fact unaddressed;

(c) the motor accident does not have to be a sole cause, as long as it is a contributing cause, which is more than negligible (to the aggravation of previous degenerative changes in the knees);

(d) contrary to the insurer's assertion, the alleged errors were incorrect in a material respect, because proper assessment of the knees would have resulted in a finding of WPI greater than 10%, as Professor Ghabrial found, and

(e) it is misleading for the insurer to allege initial knee symptoms only at 17 months post-accident. Medical Assessor Assem (at paragraph 20) of his certificate, records complaint in late 2022 relating to the knees.

1. President's delegate Ashley Payne issued a Determination of an Application for Review of a Medical Assessment on 28 January 2025 which stated the satisfaction of the President's delegate that there is a reasonable cause to suspect the medical assessment was incorrect in a material respect. The basis of that decision was stated to be Medical Assessor Assem's failure to assess and provide a pathway of reasons addressing the claimant's substantially articulated argument in relation to the question of causation and aggravation of the claimant's left and right knee.
2. The Panel directed the parties to make further submissions in relation to the following matter:

(a) whether or not re-examination of the claimant is necessary. Given that Medical Assessor Assem's clinical findings are not in dispute, in so far as the Panel can discern from the parties' submissions, causation of the knee injuries being the central issue for determination, the Panel proposes to dispense with a physical examination and to interview the claimant remotely via Teams, unless either party can persuade the Panel to the contrary. As stated previously, the parties are invited to make submissions;

(b) absent evidence of direct trauma to either knee in the motor accident, what evidence is there that the motor accident caused aggravation of previous degenerative changes in either knee? and

(c) given it is common ground that the claimant had degenerative changes in both knees, prior to the subject accident, what allowance or apportionment should be made for those pre-existing degenerative changes, in the assessment of WPI, arising from the subject accident?

In the event, both parties made further submissions (see later). The claimant required a further physical examination. The insurer consented to an assessment on the papers. In the event, was re-examined by Medical Assessor Alan Home on 23 October 2025 on behalf of the Panel.

1. A medical assessment matter is determined in accordance with Division 7.5 of the Act. The matter is determined at first instance by a Medical Assessor and, on review, by a Review Panel consisting of two Medical Assessors and a Member assigned to the Motor Accidents Division of the Personal Injury Commission (Commission).
2. Part 5 of the Personal Injury Commission Act 2020 (the PIC Act) enables the Commission to make rules with respect to the practice and procedure before the Commission, including proceedings before a Panel, reviewing a decision of a Medical Assessor.[1]
3. Rules 127 to 130 of the PIC Rules are made pursuant to Part 5 of the PIC Act. A Review Panel determines how it conducts and determines the proceedings and may determine the proceedings solely based on the written Application.[2]
4. The review of the medical assessment is by way of new assessment of all the matters with which the medical assessment is concerned.[3]
5. All members of the Review Panel had no previous involvement with the claimant or with this matter.

1. Causation of injury is addressed in the Guidelines as follows:

"6.5 An assessment of the degree of permanent impairment is a medical assessment matter under cl 2(a) of Schedule 2 of the Act. The assessment must determine the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident. A determination as to whether the injured person's impairment is related to the accident in question is therefore implied in all such assessments. Medical Assessors must be aware of the relevant provisions of the AMA 4 Guides, as well as the common law principles that would be applied by a court (or the Personal Injury Commission) in considering such issues.

6.6 Causation is defined in the Glossary at page 316 of the AMA 4 Guides as follows:

Causation means that a physical, chemical or biological factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following:

1. The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination.
2. The alleged factor did cause or contributed to the worsening of the impairment, which is a non-medical determination.

This, therefore, involves a medical decision and non-medical informed judgment.

6.7 There is no simple common test of causation that is applicable to all cases, but the accepted approach involves determining whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident. The motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible. Considering the question 'Would this injury (or impairment) have occurred if not for the accident?' may be useful in some cases, although this is not a definitive test and may be inapplicable in circumstances where there are multiple contributing causes."

1. See Briggs v IAG Limited t/as NRMA Limited.[4] See also Insurance Australia Limited t/as NRMA Insurance v Trkulja [2023] NSWSC 956,[5] wherein his Honour Justice Wright stated at (35):

"The question of causation of injuries was not dealt with in Part 5 of the Guidelines but causation was addressed in Part 6, which related to assessment of permanent impairment. There is no reason to think that different principes were intended to be applied when a medical assessment was being made in relation to causation of minor injuries."

1. Wright J then described the Panel's role in a medical review which is to:

"Consider whether the motor accident did cause or contribute to (the claimant's condition). This requires, not a consideration of material derived as a result of an internet search... but rather a consideration of the material referred to in 5.6 of the Guidelines, namely all the evidence available to the Panel, including all relevant findings derived from:

(1) a comprehensive, accurate history, including pre-accident history and pre-existing conditions;

(2) a review of all relevant records available at the assessment;

(3) a comprehensive description of the injured person's current symptoms;

(5) diagnostic tests available at the assessment, noting that imaging findings that are used to support the assessment should correspond with symptoms and findings on examination."

1. The parties have presented their respective bundles of documents upon which they rely. The Review Panel (Panel) has read all the documentation. If a particular document is not referred to by the Panel, this does not mean that the Panel, or a Panel Member, has not read it, nor taken it into consideration. The same principle applies to parties not referring to, nor specifically relying upon, a document in their own bundle and submissions.
2. The fact that evidence is not referred to in these reasons does not mean it has been overlooked. It is not required that each piece of evidence be mentioned. The Panel is not required to "analyse every piece of information from every opinion contained in a document with which it was provided". The Panel has come to its own conclusions and has taken its own history.

1. The claimant relied upon the following material which the Panel has considered:

(1) The insurer's submissions do not address the fact that the medical assessment failed to assess the referred injuries, particularly (certificate page 2.2 and 2.4) "Right knee - aggravation of previous degenerative changes" and "Left knee - aggravation of the previous degenerative changes."

(2) At certificate page 11.1 - 11.7, the assessment restricts itself to whether the osteoarthritis evident about both knees was caused by the subject collision. The referred question of aggravation is not assessed. The insurer's submissions leave that fact unaddressed.

(3) The Motor Accident Guidelines (Version 9.2) cl 6.7 includes: "The motor accident does not have to be a sole cause as long as it is a contributing cause which is more than negligible."

(4) Aggravation injuries of both knees duly assessed was more likely they not to have resulted in finding of WPI greater than 10%. Professor Ghabrial assessed 22% WPI for such aggravations, including in the cervical spine. That is significant in any view.

(5) It is misleading for the insurer to allege initial knee symptoms only at 17 months post-accident. That misreads the reasons of Medical Assessor Assem at paragraph 20 of his certificate, who there records the complaint in late 2022.

Report by qualified orthopaedic surgeon to claimant's lawyers

Mr Ahearn sustained severe injuries in a head-on collision in a motor vehicle accident on

11 February 2022. Clinical assessments and investigations suggested the following:

(1) Severe aggravation of pre-existing cervical spondylosis.

(2) Severe aggravation of his pre-existing degenerative changes in both knees.

He had no symptoms in either his neck or both knees until the motor vehicle accident until the motor vehicle accident when he started to feel pain in both knees with crepitations and instability of the left knee. Regarding the cervical spine, he continued with stiffness since the accident without any radiculopathy.

I believe that he is heading for bilateral total knee replacement in the next five years.

Form the history given to me, I believe that the motor vehicle accident is the main contributing fact to the present clinical features, disabilities and impairment.

The whole person impairment regarding the cervical spine is assessed at 5% according to DRE Category II.

The whole person impairment regarding the right knee osteoarthritic changes, 1mm cartilage interval of the medial compartment and 2mm cartilage interval in the patella-femoral compartment is assessed at 14%.

The whole person impairment regarding the left knee osteoarthritic changes 2mm cartilage interval of the medial compartment and 2mm cartilage interval in the patella-femoral compartment is assessed at 12%.

The total whole person impairment according to the Combined Values Chart in assessed at 28%.

I would deduct 1/5 of the assessed impairment due to the presence of pre-existing asymptomatic changes in the neck and both knees. That is rounded to 6% WPI and the remaining 22% WPI is the result of the motor accident..... as his symptoms in both knees developed immediately following the accident. Initially, he had no pre-existing symptoms although he had some pre-existing minor degenerative changes. I believe that the motor accident has accelerated and severely aggravated his knee problem.

"Thanks for referring Mr Ahearn regarding his right leg pain which is localised to his anterior and lateral knee and he is walking with a limp which on careful examination shows hyper extension of the knees and mild foot drop.

The pain had started spontaneously on 15 March this year. The pain is in the groin and knee and his right leg has given way a few times. He had presented to the Emergency Department at Maitland Hospital on 22 March and was discharged with Endone.

He is using a walking stick and has not been able to go for a walk since 1 April.

On further examination, his knee range of movement is full. There is no local effusion and movement of the knee joint itself does not reproduce the pain.

His quadriceps strength on the right side is Grade 3 and ankle dorsiflexion Grade 4. He has altered sensation over the L3/L4 nerve root area and the bilateral knee jerks were absent. There are no other motor neuron signs."

MRI scan of the right knee in March 2018 showed moderate osteoarthritis in the patella-femoral and medical [sic] compartments.

MRI scan of the lumbar spine in April 2018 showed a significant disc protrusion at L4/L5 compressing the L4 nerve root and causing moderate compromise of the spinal canal. L4 nerve roots were compressed on both sides. There was disc bulging at L3/L4 and L5/S1 with some nerve root compression.

MRI scan of the cervical spine in December 2019 showed generalised degenerative disc disease most prominent at C5/C6 and C6/C7 where there was mild canal stenosis and bilateral severe foraminal stenosis.

These investigations were all undertaken before the motor accident.

He appears to have suffered a soft tissue injury to his cervical spine where he has aggravated underlaying cervical spondylitis. On today's assessment, other than some minor neck stiffness, he had normal examination.

He suffered soft tissue injuries below his knees to his shins from the dashboard and these settled down eventually a couple months after the motor accident. He had no fractures.

Overall, I have come to the conclusion he did actually suffer any injury to his knees. His knees did not hit the dash and he did not develop any bruising or swelling in the knees from the motor accident. He has developed progressive osteoarthritis of the knees and these were symptomatic from the osteo arthritis prior to the accident. He now will have to consider having total knee replacement for these unrelated conditions. The specific diagnosis from the motor accident is chest injury with undisplaced fracture of the sternum from which he made a full-recovery.

(1) a soft tissue injury to his cervical spine where he aggravated underlying cervical spondylosis, and he has made a reasonably full recovery.

(2) Soft tissue injuries to the chins or lower legs below the knees from the dashboard from which has made a full recovery.

He presents with advanced osteoarthritis in his knees, but these are pre-existent conditions and here not affected by the motor accident. He did not suffer any dashboard injury to his knees.

Dr Page then expresses opinions about Treatment, Capacity and Domestic Care Needs which are not relevant for the Panel's consideration. He assesses 0% WPI.

1. The claimant's solicitor responded to paragraph 22(ii) of the Directions dated 14 April 2025 as follows:

(a) the claimant relies on his initial statement and the photographs of his motor vehicle. The claimant says there is evidence of direct trauma;

(b) as the claimant's submissions of 17 December 2024 outline, the records of the John Hunter Hospital note injuries to the lower legs and recorded symptom complaints as to pain in the upper leg. His complaints were sufficient for the staff at the John Hunter Hospital to carry out an X-ray of his right knee/tubular and fibular on 13 February 2022 (see Annexure page 58 to the claimant's original application and page 83 of the bundle). His complaints were also sufficient to have an X-ray of his pelvis at the same time;

(c) the claimant says that there was clearly direct trauma to his knees at the time of the accident, given the above records, the position of his left knee, the inflation of the below dash airbag and the contents of the claimant's statement. This is understandable given it was a combined high-speed accident;

(d) Medical Assessor Assem noted and accepted the claimant's complaints of knee pain in late 2022. The fact that complaints are not recorded in other medical records in 2022 is not determinative of their absence;

(e) the claimant has recorded the factual matters evidencing insults to both knees. Whether these were causative of aggravation of the previous degenerative changes is a matter for medical opinion. The claimant relies in this regard on the reports of Professor Ghabrial dated 3 July 2023, and

(f) the claimant has suffered no other injury to either knee since his motor accident.

1. The insurer relied upon the following material which the Panel has considered:

1. In response to the Panel's Direction dated 14 April 2025, the insurer's lawyer responded as follows (in part):

(a) the insurer submits that causation is clearly in issue. In this regard, the insurer notes that the claimant always bears the onus of proving, on the balance of probabilities, any fact relevant to issue of causation, with reference to section 5E of the Civil Liability Act 2002;

(b) As to whether the accident caused aggravation of previous degenerative changes in each knee, the insurer relies on the report of Dr Murray Hyde-Page, orthopaedic surgeon, dated 27 October 2023. On examination of the claimant's knees, Dr Hyde-Page noted:

"He has developed progressive osteoarthritis of the knees, and these were asymptomatic from the osteoarthritis prior to the motor vehicle accident."

(c) furthermore, Dr Hyde-Page reported that the claimant presents with advance pre-existent osteoarthritis in his knees not affected by the motor accident;

(d) whilst the claimant submits that the subject accident caused an aggravation of the degenerative condition of his knees, the insurer disputes this assertion and the findings in the report of Professor Yusef Ghabrial dated 3 July 2023;

(e) pursuant to paragraph 4 of Dr Ghabrial's report, the claimant state that prior to the accident, he "never had any problems with his knees, but since the accident, his knees started to give him pain." Professor Ghabrial further stated that the claimant had "no symptoms in either his neck or both knees until the motor accident". In relation to the knees, the insurer contrasts those assertions with the findings of the treating GP, Dr Saiki who stated on

15 March 2018 that the claimant reported pain in his right knee. Dr Saiki referred the claimant for an MRI of his right knee which showed moderate chondromalacia patella and thinning of the medial tibiofemoral cartilage;

(f) the claimant further admitted to Dr Hyde-Page that towards the end of his employment with Australia Post in 2017, he was experiencing significant pain in his knee from osteoarthritis;

(g) it is evidence on the available medical evidence that the claimant had demonstrated a pre-existing history of injury to his knee, which Professor Ghabrial failed to consider in his examination and findings;

(h) the insurer submits that the report of Professor Ghabrial should not be relied upon due to his failure to consider the claimant's inconsistency in reporting;

(i) the insurer submits that the claimant has not demonstrated an "aggravation" of previous degenerative changes to his knees. Rather, the evidence suggests that the claimant's knee complaints are pre-existing and not causally related to the subject accident;

(j) in paragraph (20) of his certificate, upon examination of the right knee, Medical Assessor Assem diagnosed the claimant with "right osteoarthritis, not causally related to the accident." Furthermore, the Medical Assessor highlighted that the absence of medical documentation of trauma to the right knee, coupled with a delayed onset of symptoms, will not support a causal link to the subject accident;

(k) as to the left knee, Medical Assessor Assem diagnosed the claimant with "advance osteoarthritis, not causally related to the accident";

(l) the insurer notes the Medical Assessor highlighted there was no evidence of any direct trauma to the left knee at the time of the accident, further stating that no complaints of left knee pain were recorded in any hospital, ambulance or early GP records. The insurer submits that the absence of earlier complaints in left knee pain in any of the clinical records will undermine the claim for causation, and

(m) the insurer does not make similar submissions in relation to the right knee.

1. The report of the Medical Assessor Homes is as follows:

Mr Ahearn was seen for assessment at 603/379 Pitt Street Sydney.

Mr Ahearn confirms that he suffered an episode of right lower limb pain including right knee pain around March 2018. He attended his general practitioner, Dr Sarki.

He confirms that he underwent MRI scans of the right knee performed on 22 March 2018.

He was then referred to Dr Salaria, orthopedic surgeon who arranged further imaging including MRI scans of the lumbar spine. He recalls that he was told that the leg pain was primarily coming from his back. He does recall the right knee pain and right leg pain settled within a matter of months.

There were no subsequent complaints of local pain in either knee between mid-2018 and 2022.

Mr Ahearn reports that in the subject motor vehicle accident on 11 February 2022, he was the unaccompanied seat-belted driver in a Mitsubishi SUV travelling on Lovedale Road in Lovedale when his vehicle was struck head-on by a station wagon travelling in the opposite direction.

The impact was at the front of the car. There was additional damage to the passengers' side. The front airbags deployed, including airbags below the steering wheel.

He recalls that he was assisted by a passer-by who prized open his door and assisted him from the vehicle. He was waiting for an ambulance for approximately one hour, with early symptoms of chest pain.

He was taken by ambulance to John Hunter Hospital where he underwent imaging. These studies demonstrated a fracture of the sternum, which was treated conservatively. During his hospital stay, he recalls bruising of the right shin.

He underwent x-ray imaging of the right leg and knee. No fractures were found. He was given stockings to wear on his lower limbs.

He recalls that he was wheeled out of the hospital due to difficulty mobilizing.

He remained largely housebound due to chest pain over the next six weeks. His son drove him to medical appointments.

He recalls that although he attended his general practitioner, his general practitioner then moved to Cessnock. He did attend another doctor at the same practice in Rutherford on one occasion.

He recalls that although he was referred for physical therapy directed towards his neck complaint, funding was not provided. He recalls persisting neck pain after the accident.

He confirms that he underwent x-ray and ultrasound imaging of the cervical spine in June 2022.

In relation to his right knee complaint, he recalls that he first developed symptoms of instability when ascending stairs in late 2022 or early 2023.

He recalls that he first experienced pain in his right knee in early 2023. This would particularly occur towards the end of the day after he had been walking.

In relation to his left knee complaint, he recalls the onset of local pain around mid-2023. Again, the pain was predominantly occurring with walking activity.

He states that over recent times he has been taking Panadol Osteo prescribed by his general practitioner. He takes 4-6 tablets daily.

He first underwent imaging of the right knee after a medicolegal assessment performed by Dr Ghabriel on 3 July 2023.

He is aware that imaging demonstrated bilateral osteoarthrosis of the knees.

Mr Ahearn reports current symptoms of intermittent neck pain present a few days per month, usually more prominent on the left side. There is associated stiffness turning his neck to the left. There is intermittent headache occurring when his neck pain is present.

There is no radiation of pain to the upper limbs. There are no complaints of upper limb paraesthesia or numbness.

At the right knee he described intermittent anterior pain predominantly occurring toward the end of the day. Pain can be as severe as 8 out of 10 towards the end of the day. This sometimes prevents him from standing to cook.

At the left knee, the pain is worse posteriorly. There is sometimes swelling about the knee. There is difficulty straightening the knee.

There is a restricted walking tolerance of 15-20 minutes on the flat. He has greater difficulty walking on uneven surfaces or on slopes. There is difficulty stair climbing. His knees wobble but he does not fall over.

He avoids deep squatting or kneeling through the knees.

He is right hand dominant. He prefers to stand after sitting for 15-20 minutes due to knee stiffness. There is bilateral knee stiffness after prolonged driving.

He is independent for activities of self-care. He estimates a capacity to lift and carry light weight.

He is married with three sons. He has three grandchildren. He is a non-smoker.

At his home, he helps his son with cooking, dishwashing, bench-height cleaning and laundry tasks. He has applied for cleaning assistance. He does undertake his share of the gardening. His son also assists with that.

Mr Ahearn presented as a 75-year-old standing 175 centimetres and weighing 87 kilograms. There is unsteadiness when he first stands from a sitting position.

Examination reveals normal spinal curvature without muscle spasm. Cervical spine flexion is performed to half normal range, extension one fifth normal range. Right rotation two thirds and left rotation one half. Right lateral flexion one third and left lateral flexion one quarter normal range.

Neurological examination of the upper extremities reveals no muscle wasting. There is normal myotomal power in all muscle groups. The deep tendon reflexes are symmetrically preserved. Spurling's test is bilaterally negative.

There is a fair range of active motion of both shoulders with elevation to 150 degrees bilaterally. Shoulder rotation is preserved.

The circumference of the right thigh is 44.5 centimetres.

The circumference of the left thigh is 44 centimetres.

The circumference of the right calf is 37 centimetres.

The circumference of the left calf is 36 centimetres.

Right knee joint alignment is 5 degrees valgus. There is no knee joint effusion. Active knee joint motion is measured minus 5 degrees extension lag to 120 degrees flexion. Ligaments are stable in AP and lateral planes. There is no abnormal patellofemoral joint crepitus.

Examination reveals no left knee joint effusion. Active motion is measured minus 5 degrees extension lag to 115 degrees flexion. Ligaments are stable in AP and lateral planes. There is no abnormal patellofemoral joint crepitus.

Examination of the chest reveals no abnormality to inspection or palpation. There is normal chest expansion. Auscultation is normal.

The claimant, Mr Thomas Ahearn was involved in a high-speed head-on motor vehicle accident with combined speeds estimated at 150 kilometres per hour. Airbags deployed from the steering wheel and the leg compartment.

It is well docuemnted that the claimant suffered an undisplaced sternal fracture for which he requirewd a 3-day period of hospitalization at John Hunter Hospital.

The symptoms of chest pain resolved within six weeks.

There are no current complaints of chest pain. There is no abnormality on examination of the chest.

In relation to the cervical spine, the claimant suffered early complaints of neck pain which are well documented in the medical file. The subsequent imaging demonstrated underlying cervical spondylosis.

There are no symptoms of cervical radiculoapthy and there are no clinical signs of radiculopathy. There is asymmetrical spinal motion (dysmetria).

The diagnosis is a soft tissue injury with symptomatic aggravation of underlying degenerative changes.

In relation to the right knee, the claimant was struck on the right shin at the time of the accident. Precautionary imaging of the right knee was performed, which demonstrated no abnormality.

The claimant had a previous brief episode of right knee pain in 2018 which had resolved within a matter of months. At that time right leg pain was also considered to be caused by an L4 radiculopathy, diagnosed by his treating orthopaedic surgeon.

There were no complaints of right knee pain between mid-2018 and late 2022.

The claimant's history is that he developed right knee symptoms in late 2022, some 8-10 months post-accident. There were early complaits of instability at the knee and the subsequent development of right knee pain in early 2023.

The diagnosis is osteoarthrosis of the right knee associated with a 5 degree extension lag.

I have considered causation in accordance with the principles set out in Sections 6.6 and 6.7 of the SIRA Guidelines October 2021, which direct:

6.6 Causation is defined in the Glossary at page 316 of the AMA 4 Guides as follows: "Causation means that a physical, chemical, or biologic factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following:

(a) The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination. 
>

(b) The alleged factor did cause or contribute to worsening of the impairment, which is a non-medical determination". 
> This therefore involves a medical decision and a non-medical informed judgement. 
>

6.7. There is no simple common test of causation that is applicable to all cases, but the accepted approach involves determining whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident. The motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible.

The onset of symptoms, 8-10 months post-accident is not considered to be causally related to the subject accident.

There is no mechanism whereby the accident, as described would cause arthritis in the right knee in the absence of an early fracture or other structural pathology that would change the alignment of the knee.

There is insufficient evidence that the accident is even a negligible cause fo the subsequent development of symptomatic osteoarthritis on the knee.

The claimant has developed symptoms related to constitutional osteoarthrosis that has developed progressively since late 2022 to the present date.

By mid-2023, there was radiological evidence of osteoarthrosis of the right knee.

Whilst the Panel is aware that failure of documentation is not determinative of causation, the claimant's history, restated today, is similar to that documented by Medical Assessor Assem.

That is, there were no symptoms of instability at the knee until at least 8 months post-accident (late 2022).

The first symptoms were unsteadiness, the claimant recalls developed in late 2022 with knee pain first commencing early 2023, approximately 12 months post-accident.

This history is not consistent with a diagnosis of injury caused by the motor accident in accordance with Section 6.7 of the Guidelines.

In relation to the left knee, the claimant cannot recall any history of symptoms in the left knee until the onset of pain some time in 2023, most likely mid-2023. Again, there is no mechanism whereby the motor vehicle accident as described would cause a knee injury that was not symptomatic over a period of many months and that would then contribute to the development of osteoarthrosis.

It is determined that the left knee condition has not been caused by the subject motor vehicle accident in the absence of early symptoms.

The following listed injuries WERE caused by the motor accident:

• Cervical spine: Soft tissue injury; Aggravation of pre-existing cervical spondylosis
• Chest: Sternal fracture; undisplaced - healed

The following listed injuries WERE NOT caused by the motor accident:

• Right knee: Osteoarthrosis or aggravation of osteoarthrosis
• Left knee: Osteoarthrosis or aggravation of osteoarthrosis

The determination as to permanent impairment is made in accordance with the American Medical Association's Guides to the Evaluation of Permanent Impairment (Fourth Edition) and the Motor Accident Permanent Impairment Guidelines Part 6.

Permanent impairment is defined in the American Medical Association's Guides to the Evaluation of Permanent Impairment (4th Edition) (p.315) as follows:

'Permanent impairment is impairment that has become static or well stabilised with or without medical treatment and is not likely to remit despite medical treatment. A permanent impairment is considered to be unlikely to change substantially and by more than 3% in the next year with or without medical treatment.'

The impairment in this case meets the Definition of Permanency outlined above.

The clinical presentation is consistent with a DRE Cervico-thoracic Category 2 impairment rating. There are complaints of neck pain. There is asymmetrical spinal motion (dysmetria). There is muscle guarding.

The presentation does not meet the criteria for radiculopathy set out in Section 6.138 of the SIRA Guidelines, Page 112. Radiculopathy is the impairment caused by dysfunction of a spinal nerve root or nerve roots.

To conclude that a radiculopathy is present two or more of the following signs should be found:

• loss or asymmetry of reflexes (see the definitions of clinical findings in Table 6.8 in these Guidelines)
• positive sciatic nerve root tension signs (see the definitions of clinical findings in Table 6.8 in these Guidelines)
• muscle atrophy and/or decreased limb circumference (see the definitions of clinical findings in Table 6.8 in these Guidelines)
• muscle weakness that is anatomically localised to an appropriate spinal nerve root distribution
• reproducible sensory loss that is anatomically localised to an appropriate spinal nerve root distribution.

A 5% Whole Person Impairment rating arises in accordance with the methodology set out in AMA 4, Chapter 3, Page 104.

Whilst the claimant has underlying degenrative changes there is no history or medical notation of neck pain prior to the subject accident.

A healed sternal fracture attracts a zero (0%) whole person impairment rating in accordance with Section 6.229 of the SIRA Guidelines.

The Combined Whole Person Impairment rating is 5% WPI.

AMA4, Chapter 3, Page 104

1. The Panel conducts a new assessment of all the matters with which the medical assessment is concerned.[6] The Panel adopts the examination findings and reasons of the Medical Assessor Home with which Medical Assessor Gibson agrees.
2. The Panel is not required to choose between medical opinions and is required to form its own opinions.[7]
3. The Panel met on 26 March 2025 to consider the following:

(a) the nature of the dispute and the matters in issue;

(b) whether any additional documents were required; and

(c) whether a re-examination was necessary.

1. The Panel reconvened on 13 November 2025 to consider its findings and finalise its determination.
2. The Medical Assessors have explained the basis for their assessments and findings which are similar to those of Medical Assessor Mohammed Assem.
3. The Panel finds, as a matter of medical determination and as a matter of factual non-medical judgment, that the motor accident did not cause frank injury to the claimant's knees, nor aggravated his pre-existing degenerative or osteoarthritic condition, in either knee. The Panel is not satisfied that the claimant has discharged his onus of proof under s 5E of the Civil Liability Act 2002.

1. For the above reasons, the Panel concludes that the certificate issued by Medical Assessor Mohammed Assem on 27 November 2024 should be confirmed.

[4] Briggs v IAG Limited t/as NRMA Insurance [2022] NSWSC 372.

[5] Insurance Australia Limited t/as NRMA Insurance v Trkulja [2023] NSWSC 956.

[7] Insurance Australia Group Limited v Keen [2021] NSWCA 287 and Insurance Australia Group Limited v Marsh [2021] NSWCA 31.