1. The Review Panel revokes the certificate of Medical Assessor Alexander Woo of

5 March 2025 and substitutes the determination that the following injuries were

non-threshold injuries for the purposes of the Act: * left hip - acute on chronic tear of the superior labrum with aggravation of

pre-existing osteoarthritis, and * left thigh - rupture of blood vessels in the schwannoma of the sciatic nerve.

1. The claimant, [BZI] ([BZI]), was injured in a motor vehicle accident on

24 December 2023 (the accident). 2. QBE Insurance (Australia) Limited (the insurer) was the compulsory third party insurer. 3. Under the provision of the Motor Accident Injuries Act 2017 (MAI Act) now in force, the statutory benefits after 1 April 2023 for treatment and care cease after 52 weeks if the person's only injuries resulting from the motor accident were threshold injuries. 4. Common law rights, however, do not apply to a claim for damages unless the claimant has sustained a non-threshold injury.

1. The insurer determined that [BZI] had sustained a threshold injury.
2. [BZI] filed an application in the Personal Injury Commission (Commission).
3. Pursuant to Schedule 2, cl 2 of the MAI Act, various matters are declared to be a medical assessment matters, including whether the injury caused by the motor accident was a threshold injury.
4. A medical assessment matter was determined in accordance with Division 7.5 of the MAI Act by a Medical Assessor.

1. Assent was given to the Motor Accident Injuries Amendment Act 2022 (the MAI Amendment Act) on 28 November 2022 with various amendments commencing on 1 April 2023. From

1 April 2023 the MAI Amendment Act provides that a "minor injury" was known as a "threshold injury" and "minor injuries" are known as "threshold injuries". 2. A threshold injury was defined in s 1.6 of the MAI Act and includes a "soft tissue injury". Section 1.6(2) of the MAI Act defines a "soft tissue injury" as:

"[A]n injury to tissue that connects, supports or surrounds other structures or organs of the body (such as muscles, tendons, ligaments, menisci, cartilage, fascia, fibrous tissues, fat, blood vessels and synovial membranes), but not an injury to nerves or a complete or partial rupture of tendons, ligaments, menisci or cartilage."

1. Section 1.6 provides that regulations may be made to exclude or include a specified injury from being a threshold injury. Part 1, cl 4 of the Motor Accident Injuries Regulation 2017 (the MAI Regulation) further defines threshold injury to include "an injury to the spinal nerve root that manifests in neurological signs (other than radiculopathy)."
2. Part 5 of the Motor Accidents Guidelines (the Guidelines) are made pursuant to s 10.2 of the MAI Act. The Guidelines contain the procedure for assessing whether an injury caused by the motor accident was a threshold injury for the purposes of the MAI Act. Version 10 of the Guidelines commenced on 15 September 2025 and apply to motor accidents occurring on or after 1 April 2023. As this accident occurred on 24 December 2023, the new version of the Guidelines apply. In respect of the medical assessment of whether an injury was a threshold injury, the Guidelines relevantly provide:

"5.3 The assessment will determine whether the injury related to the claim was a soft tissue injury or a threshold psychological caused by the motor accident.

5.4 Insurers should not require injured persons to undergo diagnostic imaging for the purpose of the insurer determining whether the injury related to the claim was a threshold injury. Diagnostic imaging is not considered necessary to assess threshold injury.

5.5 A diagnosis for the purpose of a threshold injury decision must be based on a clinical assessment by a medical practitioner or other suitably qualified person independent from the insurer.

5.6 The assessment of whether an injury caused by the accident was a threshold injury for the purposes of the Act should be based on the evidence available and include all relevant findings derived from:

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

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

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

(d) a careful and thorough physical and/or psychological examination

(e) diagnostic tests available at the assessment. Imaging findings that are used to support the assessment should correspond with symptoms and findings on examination."

1. In Briggs v IAG Limited Trading as NRMA Insurance [2022] NSWSC 372, 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 was no reason to think that different principles were intended to be applied when a medical assessment was being made in relation to causation of minor injuries. Clauses 6.5 to 6.7 provided:

6.5 An assessment of the degree of permanent impairment was a medical assessment matter under clause 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 was related to the accident in question was therefore implied in all such assessments. Medical assessors must be aware of the relevant provisions of the AMA4 Guides, as well as the common law principles that would be applied by a court (or claims Medical Assessor) in considering such issues.

6.6 Causation was defined in the Glossary at page 316 of the AMA4 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 was necessary to verify both of the following:

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

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

6.7 There was no simple common test of causation that was 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 was a contributing cause, which was 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 was not a definitive test and may be inapplicable in circumstances where there are multiple contributing causes'."

1. Medical Assessor Woo examined [BZI] on 28 February 2025 and certifying his decision on 5 March 2025 that the following injuries caused by the accident:
   • left hip - soft tissue injury, and
   • left thigh - soft tissue injury,

were threshold injuries for the purposes of the Act.

1. The injuries referred for assessment by the Commission to Medical Assessor Alexander Woo in respect of the dispute as to threshold injury were:
   • hip injury - aggravation of pre-existing left hip condition requiring hip replacement, and
   • thigh injury - aggravation of Schwannoma cyst in left thigh requiring surgical removal.
2. At [3]-[4], Medical Assessor Woo summarised the submissions of the parties. Essentially,

[BZI] submitted that the upper thigh and hip were asymptomatic before the accident and that the injuries were caused by the accident and were not threshold injuries.

[BZI]'s peripheral nerve had been irritated or aggravated by an internal haemorrhage to the Schwannoma. The only way in which a tumour could be removed in the peripheral nerve is by a surgical procedure, that is a cut involving damage to the nerve. The insurer submitted in summary that the internal haemorrhage would have been caused by the injury to the blood vessels. Section 1.6 of the Act includes injuries to blood vessels as soft-tissue injuries for the purposes of the Act. The insurer refers to the decision in Mandoukos v Allianz Australia Insurance Limited [2024] NSCA 71. In respect of the left hip injury, there was no evidence to support that this was injured in the accident. 3. Medical Assessor Woo then took a pre-accident history at [8], noting that [BZI] was born in South Korea and settled in Australia in 1979 at five years of age. The Medical Assessor then summarised her existing injuries/health including a CT scan of the left hip on 30 August 2019 which showed features of trochanteric bursitis; reported back pain in 2019 and likely irritation of the left L5 nerve root in the exit foramen at L5/S1; and surgical treatment for left tennis elbow after 28 March 2022. 4. At [9] of his certificate, Medical Assessor Woo took a brief history of the accident noting that [BZI], with her daughter and husband, was riding the bus when the bus driver suddenly braked and she was thrown forward to the front and subsequently fell into a chair. She reported severe pain on the left side of her body, most severe in the left arm and probably the left thigh. She was able to walk but was limping with severe pain down her left side. 5. At [10], Medical Assessor Woo took an extensive history of symptoms and treatment following the accident, which the Panel reproduces below:

"She returned to Brisbane on 27/12/2023. She had persistent pain down her left leg. She had difficulty lifting her left leg due to pain around her hip, buttock and thigh.

She came under the care of Dr Jamie Hwang and started physiotherapy. She was initially treated as sciatica pain in view of her previous history of back pain.

She had an MRI scan of the lumbar spine on 07/02/2024. This showed generalised degenerative change that is largely chronic. There is a minor diffuse disc bulge at L5-S1 with a possible left paracentral annular tear. There is no significant spinal canal stenosis or neuroforaminal narrowing. The most significant finding is of a lesion within the left thigh. It is in close proximity to the left sciatic nerve and neurovascular bundle. There is also noted an adnexal solid lesion measuring 2.6 x 2.9cm.

She went on to have a CT-guided left L4 and S1 nerve block on 11/03/2024 with no significant benefit.

Dr Hwang referred her to Dr Martin Lowe who saw her on 11/04/2024. Dr Lowe noted severe left groin, thigh and knee pain. The pain affected her sleep, and she could not get in and out of cars easily and was having severe pain down the left leg. The was predominantly lateral hip and groin but did progress down the thigh into her knee.

Examination showed restricted range of motion of the left hip, reduced external and internal rotation. There was an FFD. There was pain on abduction of the hip. Neurovascular examination was normal. There was no pain on palpation of the course of the sciatic nerve. There was no mass palpable in the posterior thigh.

X-ray and MRI of the pelvis and thigh revealed a severely degenerative left hip. There were features suggestive of a degenerative Schwannoma on the sciatic nerve.

Dr Hwang referred her to Dr Norman Ma, Neurosurgeon who saw her on 10/05/2024. Dr Ma opined that her pain was not related to her lumbar spine. There was no role for acute neurosurgical intervention.

On 13/05/2023, she had removal of a cyst from the left thigh, performed by Dr Lowe. Histology of the lesion confirmed the diagnosis of Schwannoma.

Post-operative, she continued to have left hip pain. She had CT-guided cortisone injection without much benefit. Dr Lowe recommended a total hip arthroplasty. This is a difficulty decision because of her young age.

[BZI] sought an Expert Medical Opinion report from Dr Jason Tsung, Orthopaedic surgeon.

'With respect to your osteoarthritis, this is a wear and tear phenomenon from a long period of time. There is likely a small genetic component however realistically as we age joints begin to wear. Eventually your joint becomes worn enough or so something happens to upset the apple cart such that you develop symptoms. Often this relates to worsening strength, increasing weight or stiffness of the joint.

In terms of the schwannoma, the causes of schwannoma are not known in most cases. Approximately 90% of schwannoma occur randomly with no cause identified. The remaining 10% seems to be linked to specific genetic disorders such as neurofibromatosis type 2 (NF2), Carney complex and schwannomatosis.'

Dr Tsung opined that the bus accident on 24/12/2023 has likely flared up and caused a haemorrhage to the schwannoma around the sciatic nerve in the back of the thigh. The tears in the hip were unlikely caused by the accident. It is likely these have been there for a long time. The hip symptoms are purely related to stirring up the osteoarthritis of the hip beyond its threshold point rather than the tear.

[BZI] underwent a left total hip arthroplasty on 02/09/2024, performed by

1. The Medical Assessor then set out current symptoms at [12], noting that [BZI] complains of a constant ache in her left hip and that she feels weak and tired. She told the Medical Assessor that she rates the pain level of her hip pain at 8/10 (0 no pain and 10 most severe pain) and that the pain improves to 5/10 after taking Lyrica. She also reported she has constant deep pain in her left thigh, rated at 5/10. Prior to her hip surgery, she reported a shooting pain from the buttock down to the left knee and toes with a feeling of "electric shock". This has disappeared following the total hip arthroplasty.
2. Considering current and proposed treatment at [13], Medical Assessor Woo noted that

[BZI] takes 150mg of Lyrica twice a day which helps with pain in her left hip and thigh, and that she is still attending physiotherapy once a week. 3. The Medica Assessor then undertook a clinical examination at [14]-[16] which the Panel reproduces below:

"[14] [BZI] is right hand dominant. She is 168cm in height and weighs 65kg. She has a near normal gait, as expected following a total hip arthroplasty.

[15] There was no significant leg length discrepancy. Trendelenburg sign was negative on both sides, indicating intact gluteal muscle strength in both lower limbs. Thigh and calf circumferences were the same on both sides. There were two well healed scars, a 12cm curved incision consistent with a posterior approach for the total hip arthroplasty and a second scar of 8cm at the posterior aspect of the left thigh consistent with excision of the Schwannoma cyst. Both scars were non-tender, with dull red discoloration. There was some tenderness over the left hip joint line, commonly seen after a total hip arthroplasty. The left hip had slightly limited range of motion in all directions compared to the right hip. This is considered normal following the total hip arthroplasty. There was no sensory or motor loss related to the sciatic nerve.

[16] I did not notice any inconsistencies during the assessment."

1. Medical Assessor Woo at [17]-[18] set out the relevant documentation and imagining that he relied on during his assessment, which the Panel reproduces below:

The reporting of Dr Ijaz Khan dated 16 April 2024 refers to a discussion with Dr Sanjay Patel, radiologist pertaining to the radiological imaging and reports produced. The doctors ultimately opined that the radiological imaging and reports "indicate that there is no confirmed radiological evidence of any acute or traumatic features that may be causally related to the MVA of 24 December 2023."

The report continues 'current imaging findings suggest that the left hip ... should be classified as a soft tissue injury.'

In his report date 4 June 2024, Dr Lowe notes that the claimant has 'quite severe osteoarthritis'. On examination the claimant had an "irritable hip" however maintained range of motion. Dr Lowe opined that it is likely the injury 'caused a flare of her symptoms but were not the causative effect of the underlying pathology'.

[18] Summary of relevant radiological and medical imaging and other investigations

The following radiological and medical imaging was brought to the assessment:

Dr Sanjay Patel reported: Appearance of this lesion could be primary soft tissue sarcoma or peripheral nerve sheath tumour. It is quite close to the left sciatic nerve and neurovascular bundle, but it lies quite anteriorly within the muscle and appears intramuscular. The neurovascular bundle is located posterior to the lesion.

The operative findings and histology of the lesion confirmed a Schwannoma cyst was removed. The sciatic nerve and the neurovascular bundle are intact. This indicates that there is no actual nerve injury although an open operation was performed.

Dr Sanjay Patel reported a loss of joint space within the left hip. The anterosuperior acetabular labrum is degenerative and has anterosuperior degenerative tear. There are moderate to severe osteoarthritic changes within the left hip with asymmetrical narrowing of the joint space, subchondral large cystic changes. Chondral thinning and irregularity with chondral high signal intensity

I reviewed the actual imaging of the left hip prior to the total hip arthroplasty, brought in by [BZI]. The findings are consistent with advanced osteoarthritis, which was longstanding and could not be caused by the subject accident on 24 December 2023. The post-arthroplasty imaging shows uncemented acetabular and femoral prostheses, which are commonly used for younger patients. Uncemented femoral prosthesis often gives rise to thigh pain. This could be one of the causes of the [BZI]'s ongoing thigh pain Her pre-operative shooting pain from the hip region to the knee could be a referred pain. This pain had disappeared after total hip arthroplasty. The previous thigh/knee pain was therefore likely referred pain from the hip."

1. Medical Assessor Woo arrived at his diagnosis and reasons at [19].
2. The Medical Assessor then set out his causation and reasons at [20].
3. He summarised the injuries that were caused by the accident at [21]:
   • left hip - soft tissue injury, and
   • left thigh soft tissue injury.
4. Medical Assessor Woo then set out the legislation in respect of threshold injuries and relevant regulation at [22].
5. He concluded at [23] that the injuries referred to in [21] were both soft-tissue injuries and were therefore soft-tissue injuries.

1. The Panel refers to the submissions for [BZI] of 28 March 2025 and summarises them below:

[1] [BZI] submits there is tension in the certificates of Medical Assessor Woo: one finds the arthroplasty reasonable and necessary, yet the other classifies the injury as a "threshold injury".

[2] [BZI] submits that the arthroplasty, found to be caused by the injury, must be consequential to and part of the injury caused by the accident under the Act. Paragraph [20] records that the "aggravation of pre-existing arthritis of the left hip" was caused by the motor vehicle accident, which is an aggravation not proscribed by s 4.4.

[3] The surgery necessarily involved rupturing tendons, ligaments, menisci, and cartilage, and performing a bone graft after removing the acetabular joint.

[4] In Ozcan v Macarthur Disability Services Ltd [2021] NSWCA 56, the Court held that "consequential injury" is the same injury for whole person impairment purposes under s 65(2) of the Workers Compensation Act 1987 and s 322 of the Workplace Injury Management and Workers Compensation Act 1998. Similarly, s 7.21 of the Act requires impairments to be assessed together.

[5] Causation is undefined for threshold injuries, but the Act's equivalent WPI provisions require consideration of the Guidelines, which mandate a "caused or contributed to" test under cl 1.5.

[6] The Medical Assessment Certificate arguably misapplies causation and is internally inconsistent, [BZI] submits, as the aggravation of osteoarthritis is not a threshold injury.

[7] [BZI] submits that the threshold injury Certificate is illogical and wrong because:

(a) it failed to find the aggravation of osteoarthritis was not a threshold injury;

(b) it misapplied the statutory test of causation under common law or the Guidelines, and

(c) it failed to exercise delegated power, amounting to jurisdictional error.

[8] Accordingly, [BZI] submits that the President should be satisfied there is reasonable cause to suspect the certificate is materially incorrect.

[9] [BZI] seeks re-examination by the review panel and wishes to be heard if re-examination is declined.

1. The Panel refers to the submissions of the insurer of 16 April 2025 and summaries them by reference to paragraph numbers:

[2.1] The insurer submits that [BZI] applied for a medical panel review, alleging the Certificate is incorrect in a material respect.

[2.2]-[2.3] The insurer refers to Meeuwissen v Boden [2010] NSWCA 253; (2010) 78 NSWLR 143, which requires the delegate to be satisfied that the medical assessment, not merely the Certificate, is materially incorrect. The insurer submits there must be reasonable cause to suspect error in Medical Assessor Woo's assessment.

[2.4] The insurer notes [BZI] alleges error in that:

(a) the aggravation of osteoarthritis was not found to be a non-threshold injury;

(b) the causation test was misapplied, and

(c) Medical Assessor Woo failed to exercise delegated power.

[2.5] The insurer submits the Application does not disclose sufficient grounds for review under s 7.26 of the Act and r 13 of the Motor Accident Injuries Regulation 2017.

Failure to Assess aggravation of osteoarthritis as a non-threshold injury

[3.1]-[3.2] The insurer notes that [BZI] submits Medical Assessor Woo failed to properly assess the aggravation of osteoarthritis as a non-threshold injury. She submits that the arthroplasty, found to be caused by the injury, must be consequential to and part of the "injury" caused by the motor accident.

[3.3]-[3.4] The insurer further notes that [BZI] claims that the arthroplasty caused rupture to tendons, ligaments, menisci or cartilage and therefore transformed the soft-tissue injury into a non-threshold injury under the Act. The insurer disputes these contentions, relying on Mandoukos v Allianz Australia Ltd [2023] NSW 1023.

[3.5] The insurer submits that at [110] Chen J held treatment is not an injury or consequential injury and that surgery following an accident-related injury does not constitute a further injury.

[3.6]-[3.8] The insurer further relies on Nazari v AAI Ltd t/as GIO (2) [2023] NSWPICMP 62 in support of the same principle. The insurer submits that in Nazari, the Review Panel considered whether surgery for an aggravated

pre-existing elbow injury constituted a minor injury. The insurer notes the Panel rejected that argument, finding the "injury" was not the surgical removal of hardware, as that would assess treatment rather than the underlying injury.

[3.9] The insurer refers to page 8 of Medical Assessor Woo's Certificate, where he observed that radiological imaging before the total hip arthroplasty showed "findings consistent with advanced osteoarthritis, which was longstanding and could not be caused by the subject accident."

[3.10] The insurer submits that Medical Assessor Woo properly assessed [BZI] and gave due regard to the medical evidence in determining that she sustained threshold injuries under s 1.6 of the Act.

[3.11]-[3.12] The insurer submits that Medical Assessor Woo provided sufficient reasons for his decision, noting there had been no fracture, rupture of tendons, ligaments, menisci or cartilage, and no signs of radiculopathy. The insurer further submits that Medical Assessor Woo further found no evidence of acute trauma, which was consistent with the medical evidence and the mechanism of the accident.

Failure to correctly apply the common law test of causation or as prescribed by the Guidelines

[4.1]-[4.2] The insurer notes [BZI] alleges misapplication of the test of causation established under common-law or prescribed by the Guidelines. The insurer refers to cl 6.6 of the Guidelines, which requires both medical and non-medical verification that a factor caused or contributed to the condition.

[4.3] The insurer cites the decision in Toomey v Insurance Australia Ltd t/as NRMA Insurance [2024] NSWPICMP 209, considering the issue of causation pertaining to threshold injuries having regard to both medical and non-medical determinations.

[4.4] The insurer submits that Medical Assessor Woo correctly considered

[BZI]'s chronic pre-existing osteoarthritis, her reporting, and mechanism of the accident.

(a) Medical Assessor Woo referred to a 2019 CT showing trochanteric bursitis;

(b) post-accident imaging showed severe degeneration and a Schwannoma;

(c) Dr Tsung opined symptoms were due to stirring up pre-existing osteoarthritis;

(d) no sensory or motor loss was found, and

(e) imaging confirmed advanced, long-standing osteoarthritis unrelated to the accident.

[4.6] The insurer submits that Medical Assessor Woo's causation and reasons section referred directly to the clinical, radiological and operative findings in support of his determination opinion.

[4.7] The insurer submits that Medical Assessor Woo correctly found the aggravation of osteoarthritis and injury to the blood vessels of the Schwannoma cyst were causally related but remained soft-tissue injuries under the Act.

[4.8] The insurer again relies on Mandoukos, confirming accident-related treatment is not an "injury" as defined by the Act, and therefore does not transform a non-threshold injury to a threshold injury.

[5.1]-[5.2] The insurer notes [BZI] submits jurisdictional error but provides no submissions in support. The insurer submits that Medical Assessor Woo acted independently and impartially.

[5.3] The insurer submits that Medical Assessor Woo properly considered the nature and extent of [BZI]'s injuries, medical records, and radiology.

[5.4] The insurer submits that a detailed accident history and symptoms were taken and relied upon.

1. Medical Assessor Drew Dixon examined [BZI] on behalf of the Panel via audio-visual link on 18 August 2025.

1. Medical Assessor Dixon took a history of the accident.
2. [BZI] sustained injuries to her left hip and thigh in the subject bus accident on

24 December 2023. She and her husband and daughter had flown down from Brisbane to Sydney Airport to spend Christmas with her mother who lived in Marrickville, Sydney. They were hiring an Avis rent-a- car, however, there was reconstruction at the Airport and the Avis counter had been moved so they took a bus to the hire car office. It was raining. She was standing up in the bus with bags beside her when the driver suddenly braked and she flew forward onto the floor headfirst, injuring her left hip and thigh, with her head down near the opening of the bus. She was helped to her feet by her husband. The bus driver then engaged the brakes again suddenly and she fell onto a lady's lap beside her in the bus. She felt unsteady on her feet. The bus driver kept driving. After the next two or three stops, she alighted the bus with her husband and daughter.

1. He then took a treatment history of [BZI].
2. She subsequently tried to attend the Matraville Medical Centre but it was closed for the Christmas holidays. She subsequently had review at a local medical centre in Maroubra and was advised to have scans in Brisbane for the injury to her right hip and thigh.
3. She returned to Brisbane on 27 December 2023 with persisting pain down her left thigh and difficulty lifting the leg due to pain at her left hip, buttock and thigh. She was under the care of LMO, Dr Jamie Hwang and started physiotherapy. She was initially treated for sciatic pain in view of her previous history of back pain and an MRI of the lumbar spine on 7 February 2024 had shown generalised spondylosis with a minor disc bulge at L5/S1 and possibly a paracentral annular tear.
4. An MRI of the left thigh showed soft tissue tumour in close proximity to the left sciatic nerve as a neurovascular left adnexal solid lesion measuring 2.6cm by 2.9cm. She subsequently had a CT guided left L4 and S1 nerve block on 11 March 2024 without sustained benefit.
5. She was then referred to an orthopaedic specialist, Dr Lowe, who noted severe groin, thigh and knee pain with night pain and difficulty getting in and out of cars. The pain did go down the thigh towards her left knee. Dr Lowe found there was a restricted range of motion of the left hip with pain on abduction and that neurovascular examination was normal and there was no pain on palpation of the course of the sciatic nerve and no patent mass palpable in the posterior thigh.
6. X-ray and MRI of the pelvis and thigh on 12 March 2024 revealed osteoarthritis of the left hip with an anterior superior labral tear and features suggestive of a Schwannoma on the sciatic nerve. She was referred to Dr Norman Ma, neurosurgeon who, on 10 May 2024 noted that the claimant's pain was not related to the lumbar spine and there was no role for acute neurological intervention.
7. On 13 May 2024 she had removal of a cyst from the left thigh performed by Dr Lowe and histology confirmed Schwannoma. The Schwannoma showed signs of bleeding within the tumour which was consistent with direct trauma.
8. Post-operatively, she continued to have left hip pain and a CT guided cortisone injection did not have sustained benefit.
9. She subsequently had left total hip replacement on 2 September 2024 by Dr Lowe at Wesley Hospital in Brisbane. Her immediate post-operative period was uneventful and after four days, she was discharged with crutches in a wheelchair to have outpatient physiotherapy. She continued to complain of pain in her left hip and left groin and as well as pain deep in her groin, she still has pain in the thigh when lying down. She describes some dysthesia in the left and right buttocks and reports she was unable to lie on the surgical scar where she has had the total hip replacement performed on the left through a posterolateral approach.
10. She was prescribed Lyrica for neuropathic pain and Panadol for pain relief. She was unable to tolerate an anti-depressant and has had physiotherapy ongoing which has included therapeutic massage and cupping.
11. Lyrica is helping neuropathic pain in her left thigh and the dysthesia but she still had residual deep pain in the left thigh. Lyrica 150mg twice a day improves the pain in her left hip and thigh and she is still having physiotherapy regularly.
12. MRI of the left hip on 13 March 2024, as noted above, showed anterior superior acetabular labrum with a degenerative labral tear and moderate to severe osteoarthritis of the left hip with chondral thinning. The findings were consistent with asymptomatic osteoarthritis that had been aggravated by the subject accident.
13. A further X-ray of the left hip is being done this week in Brisbane and apparently the post-op X-ray had shown the cemented total hip replacement in good position and no component loosening.

1. Medical Assessor Dixon then discussed the provided radiological investigations.
2. Acc Ultrasound of the left shoulder on 15 May 2025 showed subacromial bursitis.
3. MRI of the left shoulder on 19 August 2025 showed anterior inferior labral tear with thickened MGHL and IGHL, consistent with scarring and widened AC joint. There is subscapularis tendonosis and no rotator cuff tear.

1. Medical Assessor Dixon then provided his summary.
2. In summary this claimant was involved in a severe motor vehicle accident when the bus she was travelling on at Sydney Airport braked twice suddenly, the first time she was thrown down the bus head first to the stairwell of the bus with her legs behind her and she was helped to her feet by her husband and then the bus driver braked suddenly a second time and she fell onto the lap of a lady who was sitting.
3. She sustained a significant injury to the left hip with groin pain and a significant injury to her left thigh. Radiologically, she has acute on chronic tear and a degenerate anterior superior labrum of the left hip as well as aggravating asymptomatic pre-existing osteoarthritis.
4. She has directly traumatised a Schwannoma in her left thigh which has bled due to the rupture of small vessels within the benign tumour, despite its removal, and is still associated with pain in the left thigh and some dysthesia in the buttock area, both left and right.
5. The Medical Assessor, in his MAC dated 5 March 2025, which was a treatment dispute, noted the total arthroplasty of the left hip including minor bone grafting and including assistant's fees related to the injury caused by the motor accident and was reasonable and necessary in the circumstances.
6. A Schwannoma is a neuroma of nerve sheath cells called a neurilemmoma. It is a non-invasive slowly growing tumour of Schwann cells and fibroblasts producing a fusiform expansion through which nerve fibres run.
7. In this claimant's case, it has involved the peripheral nerve, that is the left sciatic nerve.
8. In the subject motor vehicle accident, there has been direct trauma to the Schwannoma which showed haemorrhage within it when it was removed. This indicates there have been rupture of the small blood vessels in the neuroma within the Schwannoma, consistent with direct trauma. In this claimant's case, it has been associated with ongoing pain in the thigh and dysthesia in the buttock area due to residual sciatic nerve irritation.
9. She did have pre-existing asymptomatic osteoarthritis of the left hip with a degenerative labrum and the radiologist has said this was a chronic tear of the superior labrum in the subject motor vehicle accident.
10. Medical Assessor Dixon believed that this was an acute on chronic tear following the subject nature of her fall in the severe bus accident, but for the injury to the hip as a result of the bus accident being causative of an acute on chronic tear as well as increasing groin pain due to aggravation of osteoarthritis, leading to an uncemented total hip replacement.
11. Medical Assessor Dixon concurred with Medical Assessor Alexander Woo, in his certificate dated 5 March 2025 that the total hip replacement is causal and reasonable and necessary in the circumstances of the subject motor vehicle accident.

1. The Review Panel met again on 27 August 2025 at 4.00pm, discussing the case and all of its details.
2. The entire Review Panel determined that it agreed with Medical Assessor Dixon that

[BZI]'s peripheral nerve was irritated and aggravated by internal haemorrhage to the Schwannoma and this could only have taken place if there was a rupture of the blood vessels for the purposes of the Act. 3. The rupture of the blood vessels, however, is a non-threshold injury for the purposes of the Act as described in para 10 of this submission s1.6(2) of MAI Act. 4. The Review Panel agreed with Medical Assessor Dixon that the radiology establishes that there was an acute on chronic tear of the superior labrum in the accident and this acute on chronic tear was caused by the nature of her fall in what was a severe bus accident, and but for the injury to her hip, she would not have suffered an acute on chronic tear as well as aggravating pre-existing arthritic change. 5. In all of the circumstances, the Panel determined that this was a non-threshold injury.

CONCLUSIONS AND DETERMINATIONS ON THRESHOLD INJURY DISPUTE

1. The Review Panel revokes the certificate of Medical Assessor Alexander Woo of

5 March 2025 and substitutes the determination that the following injuries were

non-threshold injuries for the purposes of the Act: * left hip - acute on chronic tear of the superior labrum with aggravation of pre-existing osteoarthritis, and * left thigh - rupture of blood vessels in the schwannoma of the sciatic nerve.