Behn v AAI Limited t/as GIO
[2024] NSWPICMP 637
•11 September 2024
| DETERMINATION OF REVIEW PANEL | |
CITATION: | Behn v AAI Limited t/as GIO [2024] NSWPICMP 637 |
CLAIMANT: | Jonathan Behn |
INSURER: | AAI Limited t/as GIO |
REVIEW PANEL | |
PRINCIPAL MEMBER: | John Harris |
MEDICAL ASSESSOR: | Christopher Oates |
MEDICAL ASSESSOR: | Shane Moloney |
DATE OF DECISION: | 11 September 2024 |
CATCHWORDS: | MOTOR ACCIDENTS – Motor Accident Injuries Act 2017; physical injury; assessment of whole person impairment (WPI); car door opened on bike rider impacting left shoulder; repeated clinical opinions diagnosed brachial plexus injury despite scan findings; injury often diagnosed clinically; injury consistent with motor accident; claimant suffered soft tissue left shoulder injury; direct trauma to the anterior part of the left shoulder; slightly greater loss of movement is explicable due to slight variations over time; Held – claimant suffered brachial plexus and left shoulder injuries; WPI assessed at greater than 10%; Medical Assessment Certificate revoked. |
DETERMINATIONS MADE: | Medical Assessment – Permanent Impairment Certificate WHETHER THE DEGREE OF PERMANENT IMPAIRMENT OF THE INJURED PERSON AS A RESULT OF THE INJURY CAUSED BY THE MOTOR ACCIDENT IS GREATER THAN 10% THE ASSESSMENT MADE BY THE REVIEW PANEL UNDER S 7.23(1) OF THE MOTOR ACCIDENT INJURIES ACT 2017 IS AS FOLLOWS: The Panel revokes the medical assessment certificate dated 1 February 2024 and certifies that the following injuries caused by the motor accident give rise to a permanent impairment greater than 10%: · Brachial plexus, and · left shoulder – soft tissue. |
REASONS
BACKGROUND
On 28 March 2022 Mr Jonathan Behn (the claimant) was injured whilst riding his motorcycle. The insured driver opened the car door which collided with the claimant’s left shoulder.[1]
[1] Claimant’s bundle, p 14.
AAI Ltd (the insurer) insured the owner and/or driver of the motor vehicle for liability to pay to Mr Behn any damages and/or statutory benefits under the Motor Accident Injuries Act 2017 (the MAI Act).
The issue in this medical dispute is whether Mr Behn’s “degree of permanent impairment as a result of the injury caused by the motor accident is greater than 10%”. This constitutes a medical dispute within the meaning of the MAI Act.[2]
[2] See Division 7.5 and Schedule 2, cl 2 of the MAI Act.
Section 7.21 of the MAI Act provides that the degree of permanent impairment of an injured person is to be made in accordance with the Motor Accident Guidelines (the Guidelines).
The Guidelines are issued pursuant to s 10.2 of the MAI Act. The Guidelines adopt the fourth edition of the American Medical Association’s Guides to the Evaluation of Permanent Impairment (AMA4). Where there is any difference between AMA4 and the Guidelines, the Guidelines are definitive.[3]
[3] Clause 6.2 of the Guidelines.
This is a review of a medical assessment pursuant to s 7.26 of the MAI Act. The medical assessment the subject of this review was conducted by Medical Assessor Kenna and dated 1 February 2024 (the medical assessment certificate).[4]
THE REVIEW
[4] Insurer’s bundle, p 30.
The application for referral of a medical assessment to a Review Panel (the Panel) was made by the claimant within 28 days after the parties were issued with the original certificate for which the review is sought.[5]
[5] Section 7.26(10) of the MAI Act.
The President referred the medical assessment to the Panel as they were satisfied that there was reasonable cause to suspect that the medical assessment was incorrect in a material respect having regard to the particulars set out in the application.[6]
[6] Section 7.26(5) of the MAI Act.
Pursuant to s 7.26(5A) of the MAI Act and Schedule 1, cl 14F(2) of the Personal Injury Commission Act 2020 (the PIC Act), the Panel consists of two Medical Assessors and a Member of the Motor Accidents Division of the Personal Injury Commission (Commission).
Part 5 of 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 Merit Reviewer or a Medical Assessor.[7]
[7] Section 41(2) of the PIC Act.
Rules 127 to 130 of the Personal Injury Commission Rules 2021 (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.[8]
[8] Rule 128 of the PIC Rules.
The review is by way of new assessment of all matters with which the medical assessment is concerned.[9]
[9] Section 7.26(6) of the MAI Act.
The parties filed bundles of documents for the Panel’s consideration.
STATUTORY PROVISIONS
The provisions of the Civil Liability Act 2002 (the CL Act) apply to the MAI Act in determining issues of causation. Particularly ss 5D and 5E of the CL Act.[10] In Raina v CIC Allianz Insurance Ltd[11] Campbell J stated:
“One may accept that a review panel is engaged in a process of dispute resolution by expert assessment of medical issues arising under the Act. However, the questions arise in a legal context and it is incumbent upon the panel, medical practitioners they may be, to correctly apply the law including the law of causation in the exercise of their powers. This includes the provisions of Division 3 of Part 1A of the Civil Liability Act 2002 (NSW), ss5D and 5E: see s 3B(2)(a) of that Act. Although it may be expected that questions about the appropriate scope of liability will arise but rarely.”
[10] See s 3B(2) of the CL Act.
[11] [2021] NSWSC 13 (Raina) at [65].
Further, cls 6.5 to 6.7 of the Guidelines refer to causation of both injury and whether the degree of permanent impairment is caused by injury.
Clause 6.7 of the Guidelines provides:
“There is no simple common test of causation that is applicable in 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 the sole cause as long as it is a contributing cause, which is more than negligible.”
ASSESSMENT UNDER REVIEW
The Medical Assessor found that the claimant suffered a left lower branch brachial plexus injury and limitation of the left shoulder due to the “Nguyen effect”.[12]
[12] Insurer’s bundle, p 30.
The Medical Assessor found a brachial plexus injury with sensory deficit to the lower trunk of the brachial plexus involving C8/T1, graded as 3 due to decreased sensibility and assessed at 7% permanent impairment. The Medical Assessor also found left shoulder symptomatology with reduction in motion assessed at 3% impairment.
The Medical Assessor did not assess the cervical spine symptoms as he opined that it would “result in double dipping”.
MATERIAL BEFORE THE PANEL
The parties filed bundle of documents for the Panel’s consideration.
Pre-existing conditions
There is no history of relevant prior symptoms affecting the subject body parts save as to the injury at aged 12 to the left shoulder. On the history provided there was no ongoing issues following that incident.
Medical records post-accident
The clinical note of the GP dated 29 March 2022 recorded:[13]
[13] Claimant’s bundle, p 22.
“Come in 1 day after MBA 10 am yesterday
Car door opened by police officer on Bigge St while estimated 40 kmph
Remained up right but left arm hyperextended and abducted
Checked by ambulance not taken to hospital
No open wound or new injury noted
….
Mildly tender left paraspinal lumbar/lat dorsi
NVI left upper limb resolving paraesthesia 4th/5th finger
No ulnar impaction signs
Imp: resolving neuropraxia and muscular signs”
A certificate of capacity dated 7 April 2022 referred to “left arm blunt trauma”.[14] The clinical note then referred to left 4th/5th finger numbness and shoulder pain”.[15]
[14] Claimant’s bundle, p 18.
[15] Claimant’s bundle, p 22.
The claimant completed a claim form on 12 April 2022.[16] Mr Behn alleged that the insured vehicle “contacted into left shoulder joint, causing arm to go numb, feeling has not returned and pain across shoulder”.
[16] Claimant’s bundle, p 17.
The X-rays of the left hand, left elbow and left shoulder did not show any fracture, subluxation or abnormality.[17]
[17] Claimant’s bundle, p 24.
On 14 April 2022 the GP referred the claimant for “left shoulder exercises for rotator cuff injury”.[18]
[18] Claimant’s bundle, p 31.
The left shoulder ultrasound dated 4 May 2022 showed mild thickening of the subacromial subdeltoid bursa and impingement with no significant rotator cuff tendinosis or tear evident.[19]
[19] Insurer’s bundle, p 45.
The MRI of the cervical spine dated 1 July 2022 noted ongoing numbness and weakness in the left hand and showed “cervical spondylosis with potential for nerve root impingement at some levels”.[20]
[20] Insurer’s bundle, p 49.
Dr Ho Choong, neurologist, provided a report dated 1 July 2022.[21] The doctor opined that the residual numbness in the medial aspect of the left forearm and hand and the pain in the position of the left shoulder was due to a left lower brachial plexus lesion.
[21] Insurer’s bundle, p 47.
The thoracic outlet vascular ultrasound dated 21 September 2022 was reported as normal.[22]
[22] Insurer’s bundle, p 52.
The left upper limb EMG study dated 4 November 2022 was reported as being within normal limits.[23]
[23] Insurer’s bundle, p 53.
The claimant was reviewed by Dr Choong on 4 November 2022.[24] Following a review of the radiology, Dr Choong opined that it was “possible” that the claimant had “mild left thoracic outlet neurogenic syndrome” and recommended ongoing conservative management.
[24] Insurer’s bundle, p 89.
An Allied health recovery request (AHRR) dated 18 May 2023 referred to “tension neuropraxias to L brachial plexus”.[25]
[25] Insurer’s bundle, p 75.
Qualified opinions
Professor Ian Cameron, physician, was qualified by the insurer and provided a report dated 18 December 2023.[26] Ongoing left arm symptoms were noted by the doctor during the examination.
[26] Insurer’s bundle, p 16.
Professor Cameron opined:[27]
“In the motorcycle accident on 28 March 2022 Mr Behn sustained an injury to his left upper chest. The findings on examination are consistent with an incomplete left lower trunk brachial plexus injury. Mr Behn has convincing residual symptoms of neurological sensory deficit.”
[27] Insurer’s bundle, p 19.
In a further report dated 18 December 2023, Professor Cameron assessed impairment due to the brachial plexus injury at 12% upper extremity impairment based on sensory grade 3 without motor loss and the left shoulder at 3% upper extremity impairment. This resulted in a combined assessment of 9% permanent impairment.
SUBMISSIONS
Claimant’s submissions dated 12 September 2023[28]
[28] Claimant’s bundle, p 1.
The claimant referred the “following injuries for assessment” of the degree of permanent impairment:
(a) left shoulder – orthopaedic injury, aggravation and acceleration of degenerative changes;
(b) left arm – soft tissue injury, orthopaedic injury, aggravation and acceleration of degenerative changes, and
(c) left hand – numbness and paraesthesia in fourth and fifth fingers, soft tissue injury, orthopaedic injury, aggravation and acceleration of degenerative changes.
Claimant’s submissions dated 18 March 2024[29]
[29] Claimant’s bundle, p 2.
These submissions were filed seeking a review of the medical assessment.
The claimant noted that the Medical Assessor diagnosed an injury to the cervical spine but declined to assess that body part because it would “result in double dipping”. It was submitted that the issue of double dipping is not identified anywhere in the guidelines and cl 6.45 contemplated multiple injuries being assessed and their respective impairments combined.
The claimant submitted that the Medical Assessor failed to fully disclose his reasoning in determining why the cervical spine injury should be excluded from the determination.
The claimant submitted that the reasons of the Medical Assessor are deficient in assessing the brachial plexus impairment by failing to explain why the claimant was placed in grade 3. The claimant referred to the criteria for the evaluation of sensory deficit and pain contained in page 46 of the AMA 4 and submitted that there was no discussion in the medical assessment certificate of the various criteria.
The claimant submitted that the Medical Assessor, having identified a cervical spine injury, failed to apply the principles in Nguyen v Motor Accidents Authority of NSW[30] in assessing whether there was any reduced range of motion in the left shoulder.
[30] [2011] NSWSC 351 (Nguyen).
The claimant referred to passages in the medical assessment certificate such as well-defined numbness on the medial aspect of left forearm involving the fourth and fifth fingers and the conclusion that two-point discrimination sensation was normal. It was submitted that this inconsistency should have been put to the claimant pursuant to cl 6.41 of the Guidelines.
The claimant submitted that the measurements contained in the medical assessment certificate relating to muscle wasting and reduce shoulder range of motion were not taken by any device and referred to his statement attached to the submissions.
Insurer’s submissions dated 5 July 2023[31]
[31] Claimant’s bundle, p 8.
The insurer denied that the claimant’s permanent impairment exceeded 10% and referred to the following radiological studies:
(a) X-ray of the left upper limb dated 12 April 2022 showed no abnormality;
(b) Ultrasound of the left upper limb dated 4 May 2022 showed no abnormality;
(c) nerve conduction study dated 1 July 2022 showed values within normal limits;
(d) MRI scan of the cervical spine dated 1 July 2022 showed no significant disc protrusion, and
(e) Electromyography report dated 4 November 2022 was normal with no nerve root or lower brachial plexus injury.
Insurer’s submissions dated 5 July 2023[32]
[32] Insurer’s bundle, p 12.
The insurer noted that the claimant had not provided any evidence to support the assertion that the impairment exceeded 10%. It noted that it had scheduled an examination with Professor Cameron.
The insurer referred to the “numerous investigations” purporting to diagnose the left upper limb symptoms noting the left ultrasound demonstrated subacromial bursitis and that in November 2022 Dr Choong opined that it was possible that the claimant had mild left thoracic outlet neurogenic syndrome.
The insurer submitted that without an aetiological explanation, there was difficulty in establishing stabilisation of the claimant’s injuries.
Insurer’s submissions dated 9 April 2024[33]
[33] Insurer’s bundle, p 2.
These submissions opposed the application to review the medical assessment.
The insurer noted that the cervical spine was not referred for assessment. It also submitted that there was no finding of injury to the cervical spine.
In respect of the assessment of the brachial plexus injury the insurer noted that the claimant continues to work and referred to the clinical symptoms found by the Medical Assessor.
The insurer submitted that the Medical Assessor correctly applied the Nguyen principle to any assessment of the left shoulder.
The insurer submitted that the claimant incorrectly submitted that the Medical Assessor found inconsistency. It otherwise noted that the Medical Assessor was required to use “the entire gamut of clinical skill and judgment” in assessing measurements and had otherwise used a goniometer.
RE-EXAMINATION
Mr Behn was examined by Medical Assessor Oates on 29 August 2024. The examination report is as follows:
“Mr Behn attended unaccompanied for assessment by Medical Assessor Oates on behalf of the Medical Review Panel.
HISTORY
Pre-accident medical history and relevant personal details
Mr Behn said he is right-handed and resides at Picton in a single-storey house on a mate’s property. He lives with his wife (who is his third wife). She works casual part-time. They have two sons: one aged 2.5 years and the younger aged three months. His 2.5-year-old weighs 14kg and his three-month-old weighs 4.4kg.
At the time of the accident, he worked as a 4WD motor mechanic and has been a mechanic since the age of 18, although he was a spray-painter by trade but left because of development of isocyanate toxicity.
He last worked in July 2023 for about one month and was in the process of setting up a workshop for caravans, but it did not proceed. He is hoping to take over a caravan sales branch within a month.
He found that after the accident when he tried to return to mechanic work, he couldn’t work on the tools because if he over-used his left arm at shoulder height or had weight dragging down on his left arm, it would affect his shoulder. He also has difficulty holding his older son for too long.
He used to play golf and played simulated car racing online and also rode motorbikes and was involved in production car motor racing.
He had had no previous problems with the neck, shoulders or arms.
He had a fractured skull when he fell from a pushbike at the age of eight years in his backyard. He had an arthroscopy of the left ankle in 2008.
He has had no serious illnesses.
He was usually on no regular medications.
Mr Behn subsequently remembered that he had dislocated his left shoulder on a go-kart at age 12. His mother was a nurse, and she was able to reduce the dislocation of the left shoulder almost immediately. He did not require any further treatment, as there was no further dislocation.
History of the motor accident
Mr Behn said on 28 March 2022, he was riding his motorcycle north along Bigge Street, Liverpool, towards Elizabeth Street, and came upon a car which was parked on the left side of the road illegally. He could not see anyone in the car and as he rode up to it, the driver’s door suddenly opened into the path of the motorbike. He was in the lane beside the parked car. He was travelling at about 30-40kph. At the time he was wearing a full-face motorcycle helmet and had full riding gear including gloves and boots on.
When he saw impact was imminent, he put his left hand up towards his right shoulder, thus crossing his left arm across the front of the body. The door hit the front axle of the bike. The momentum pulled him in towards the door and the door brushed his lateral left lower leg, and the top corner of the door hit his left upper pectoral anterior shoulder area. The force of the impact bent the door further forward than its usual maximum opening angle.
His bike went sideways but he stayed on it and managed to stop it about one car length in front. His main concern at the time of the impact was he was worried about the status of his groin, which had impacted heavily against the fuel tank. He got off the bike and was on the kerb feeling nauseous. He noticed he could not feel his left arm. He kept it cradled across the front of his chest.
The ambulance arrived and he was helped out of his riding jacket. The paramedics checked him over. He was told there would be a three hour wait at the hospital, so he elected to go to his GP, which he did the next day. He had the bike taken away. It was subsequently repaired at a cost of $15,000. He got a lift to his workplace and then his boss dropped him back home.
History of symptoms and treatment following the motor accident
He went to his GP, Dr Ricky Harjanto, Campbelltown Mall, on 29 March 2022. He had bruises on the left upper chest, left knee and left foot.
The morning after the accident, he noticed his whole left arm felt numb radiating into the 4th and 5th fingers of the left hand, and the other fingers were partly numb. He was put off work for 2.5 weeks.
He had x-rays of the left arm and then an MRI scan of the neck.
He subsequently returned to light duties for two weeks and then there were no further light duties available, so he tried some more physical work as a mechanic, but was dropping things and caught his thumb in a spring because the numbness in the medial aspect of the left hand affected his manual dexterity. He then resigned.
He lived on his savings and sold one set of his tools and two of his cars.
He was treated with physiotherapy, which he continued until about four months ago. It helped with increasing range of movement and strengthening of the peri-scapular muscles. This helped him regain proper elevation movement of the left shoulder, which had been limited. He learnt how not to trigger the numbness in the left forearm and hand, but it still comes back if he lets his shoulder sag downwards. If he sits and moves with his left shoulder slightly elevated, there is less triggering of the numbness.
He was referred to Dr Choong, neurologist, whom he saw on 1 July 2022. An upper limb nerve conduction study was said to show a mild left antebrachial cutaneous neuropathy and incidental borderline carpal tunnel syndrome and borderline right ulnar nerve lesion.
MRI scan of the cervical spine showed some multi-level degenerative spondylosis but no irritation or compression of the left C8 and T1 nerve roots, which would be expected if it were the cause of numbness and paraesthesia in the left little and ring fingers.
He had a vascular ultrasound of the left upper extremity which was negative for thoracic outlet syndrome. He had a needle electromyography which was normal and indicated no evidence of left C8 and T1 nerve root lesion, nor of any lower brachial plexus injury or damage.
After this, he had his final review with Dr Choong on 4 November 2022 and was diagnosed with a mild left thoracic outlet neurogenic syndrome, but there was no actual nerve impingement which boded for a good prognosis, and he was advised to continue with conservative treatment and to come back if the situation changed.
Details of any injuries or conditions sustained since the motor accident
He said in November 2023, he was going down the stairs and went to grab the balustrade with a reflex action with his left hand, and he lost his grip and fell on his backside. He did not upset his arm in this incident.
About four weeks ago, he was coming down the stairs and again missed the balustrade with his left hand and fell on the steps, landing on his hands, particularly the right hand, and this did stir up his left arm numbness and tingling for a couple of days and then it returned to its usual status.
Current symptoms
He remains under the care of Dr Harjanto in Campbelltown. He has a constant dull ache over the left trapezius area to the lateral left upper arm and if he overuses the left arm, the ache changes to a burning pain from just below the left shoulder joint proximally to the left upper trapezius, but not as far as the neck, and also distally to the lateral left upper arm and forearm towards the dorsum of the left hand, with dullness distal to the left elbow, to the medial forearm and down to the left little and ring fingers. He gets numbness in these two fingers and the ulnar aspect of the hand and adjacent distal forearm after the onset of the burning pain.
He can elevate the left arm at the shoulder to about 130° in flexion and abduction, then has the onset of the twinge in the shoulder, and then burning and numbness down the left arm to the ulnar two fingers. He found he had to change the type of wedding ring he wears because he could not feel the one he used to have and it would slip off unnoticed.
Current and proposed treatment
He takes no medications. He does home exercises using Therabands given to him by the physiotherapist and where he now lives, they have given permission for him to attach hooks to the wall so he can use the bands overhead for elevation exercises.
He doesn’t take recreational drugs or smoke cigarettes and has very little alcohol, about one or two drinks per month.
EXAMINATION
General presentation
He was of solid build with height 180cm and weight 131kg.
He stood erect and his trapezial ridges were level, in that there was no hitching or depression of the shoulders. There was no scalene muscle tightness on either side to palpation.
Cervical spine (cervicothoracic)
There was no guarding or muscle spasm. There was no focal tenderness. Flexion and extension were full. Lateral flexion was one-half normal bilaterally. Rotation was two-thirds of normal bilaterally. There was no asymmetric loss of active range of motion.
The scalene tests were negative. He did report some feeling of stiffness when rotating the head to the right in his left upper quadrant area.
Upper limb reflexes were all of low amplitude but symmetrical. Power was equal in the upper limbs. Tinel’s sign was positive over the right medial elbow but negative over the left medial elbow at the ulnar groove. Tinel’s sign was positive over the right median nerve at the wrist but negative over the left median nerve at the wrist.
His pupils were equal and normally reactive – no Horner’s syndrome was present.
There was reduced two-point discrimination (>15mm) over the left ring and little fingers, and the adjacent ulnar aspect of the hand. There was no thenar or hypothenar muscle wasting visible. There was no weakness of left flexor carpi ulnaris, flexor digitorum profundus or the left-hand intrinsic muscles.
There was partial decrease of sensation in the ulnar left forearm distal to the elbow, but sensation was intact proximal to the elbow in the left arm and in the whole of the right arm.
The wall press test was negative bilaterally for brachial plexus lesion.
Upper arm girth; right 37cm, left 37cm at 10cm above the elbow crease. Forearm girth; right 33cm, left 32.5cm at 5cm below the elbow crease. This is consistent with stated right-hand dominance.
Shoulder Movements
Active ROM measured
RIGHT
Active ROM measured
LEFT
Flexion
180°
130°, 130°, 130°
Extension
50°
40°, 40°, 40°
Adduction
50°
40°, 40°, 40°
Abduction
180°
130°, 130°, 130°
Internal rotation
90°
70°, 70°, 70°
External rotation
90°
60°, 60°, 60°
The range of movement was measured with a goniometer.
Flexion on the left shoulder was limited by complaints of tingling and discomfort down the left arm to the dorsal aspect of the forearm. Extension was limited by tingling down the left arm to the ulnar two fingers. Abduction of the left shoulder was limited by burning and tingling down the left arm to the dorsal forearm, as was internal and external rotation.
There was full range of movement at right and left elbow, right and left wrists, and right and left hands.
Comments on consistency
The claimant presented in a straightforward manner. There was no evident inconsistency.
IMAGING
There was no imaging brought to the examination.
From the file:
12/4/2022 – X-ray left hand – Normal.
X-ray left elbow – Normal.
X-ray left shoulder – Normal.
4/5/2022 – Ultrasound scan left shoulder, left wrist – At the shoulder there is subacromial bursitis but no significant rotator cuff tendinosis or tear evident. At the left wrist there is no significant thickening of the ulnar nerve at the Guyon’s canal level. Uniform nerve thickness and fibrillary pattern demonstrated. No extrinsic compression is seen at this level or within the cubital tunnel at the elbow either.
1/7/2022 – MRI cervical spine – Multi-level cervical spondylosis with potential for nerve root impingement at some levels – Potential for traversing right C8 nerve root irritation, moderate to severe left neural exit foraminal narrowing at C4/5, mild to moderate bilateral C5/6 neural exit foraminal narrowing, mild to moderate bilateral C6/7 neural exit foraminal narrowing, moderate left C7/T1 neural exit foraminal narrowing.
21/9/2022 – Thoracic outlet vascular ultrasound left side – No suggestion of left subclavial arterial impingement.
4/11/2022 – Needle EMG – The left upper limb EMG study is within normal limits; there is no evidence of left C8 and T1 nerve root or lower brachial plexus injury or damage.
DETERMINATIONS
Diagnosis, causation and reasons
The diagnosis is contusive soft tissue injury to anterior aspect of left shoulder from direct trauma, and associated traction injury to the lower trunk of brachial plexus from a direct blow to the upper pectoral left infraclavicular area following contact between that part of the body and the open door of a car, whilst he was moving at moderate speed alongside the door.
There was no evidence of a separate cervical spine injury, nor of a more distal neurological or vascular injury affecting the left upper extremity, such as involvement of the ulnar nerve at the elbow or wrist, either on clinical examination or on special investigations
The accident was a cause of the injury, as these body parts are mentioned in the Personal Injury Claim Form and in the early GP record dating from one day after the accident, and in subsequent specialist and physiotherapy records.
Note – The mechanism of injury as recorded by the GP is inaccurate, in that there was no abduction and hyperextension of the left arm at the time of impact, but rather the left arm was cradled across the front of the chest and was in a relatively protected position at the time when the impact was borne by the left upper chest/ anterior left shoulder area, and resulting in posteriorly directed wrenching to this area as he contacted and moved past the car door whilst remaining on his moving motor cycle.
Investigations do not reveal any physical lesion affecting the brachial plexus, however there is evidence of lower trunk brachial plexus irritation, and this is persisting. Fortunately, there is no evident motor weakness, however there is continuing sensory manifestation.
Although underusage is reported, there is no left upper extremity atrophy to indicate this is significant. The underusage is in terms of avoiding certain positions and overuse of the left arm to avoid triggering of unpleasant brachial plexus irritation symptomatology.
This triggering of unpleasant symptoms of numbness and burning pain in the distribution of the lower trunk brachial plexus has interfered with his ability to continue in his pre-accident heavy work as a 4WD motor mechanic because the numbness was interfering with his ability to hold tools and also the onset of symptoms was triggered by having to position his arm above shoulder height at various times when working on motor vehicles.
PERMANENT IMPAIRMENT
With respect to the left shoulder, there is measurable reproducible loss of active range of motion which forms the basis for assessing impairment.
Flexion 130° gives 3% upper extremity impairment, extension 40° gives 1%, abduction 130° gives 2%, internal rotation 70° gives 1%. Adding these gives 7% upper extremity impairment.
For the lower trunk brachial plexus, there is a Grade 3 sensory deficit in terms of decreased sensibility with abnormal sensation or pain which interferes with activity, giving 60% of the maximum sensory deficit.
For the lower trunk, the maximum upper extremity impairment for sensory deficit or pain is 20%. 60% by 20% gives 12% upper extremity impairment.
Combining 12% by 7% gives 18% upper extremity impairment using the Combined Values Chart.
From Table 3, page 20, 18% upper extremity impairment is equivalent to 11% whole person impairment.
Body Part or System
AMA4 Guides/ Guidelines References
(chapter/ page/table)
Permanent (YES/NO)
Current %WPI*
%WPI* from pre-existing OR subsequent causes
%WPI* due to motor accident
Left shoulder
AMA4, Chapter 3, Figures 38, 41 & 44, page 43-45; Table 3, page 20
Yes
4
0
4
Brachial plexus lower trunk
Table 11A, Grade 3, Table 14, Chapter 3
Yes
7
0
7
* %WPI = percentage whole person impairment
The combined impairment is 11% whole person impairment.
Apportionment, pre-existing or subsequent impairment and effects of treatment
There was no indication of a pre-existing permanent impairment affecting the injured body parts and no evidence of a relevant subsequent impairment.
Therefore, there is no indication for apportionment of the assessed permanent impairment.
There is no indication that treatment has the potential to modify the impairment. Treatment has been mainly symptomatic consisting of physiotherapy and exercises.”
FINDINGS
The Panel conducts a new assessment of all the matters with which the medical assessment is concerned.[34]
[34] Section 7.26(6) of the MAI Act.
The Panel, comprised of two specialist medical practitioners, is not required to choose between competing medical opinions and is required to form its own opinion: Insurance Australia Group Ltd v Keen[35] and Insurance Australia Ltd v Marsh.[36]
[35] [2021] NSWCA 287 at [40], [41] and [45].
[36] [2022] NSWCA 31 at [11], [21] and [64].
The Panel adopts the examination report provided by the Medical Assessor supplemented by the following further reasons.
The claimant has been repeatedly assessed clinically as suffering from a brachial plexus injury. The nature of this injury is entirely consistent with the mechanism of the motor accident when the left arm was struck by the car door at speed. Those clinical findings of brachial plexus were again found by Medical Assessor Oates during the recent examination.
We note that the scans did not show brachial plexus injury. However, brachial plexopathy is often made clinically even in the absence of supportive investigations. In this case Mr Behn was repeatedly tested and satisfied all clinicians that he had a brachial plexopathy.
We also accept that the clinical features show loss of movement in the left shoulder due to the nature of the soft tissue trauma sustained in the motor accident. This conclusion is based on an accepted clinical history of direct trauma to the anterior left shoulder, the ultrasound which showed subacromial bursitis, absence of prior symptoms and repeatedly observed left shoulder loss of movement since the motor accident. The assessment of Medical Assessor Oates, whilst slightly different from earlier examinations, are consistent with prior findings and were repeatedly tested by him to ensure consistency during the examination. The slight difference in range of movement, whilst important in this case, is explicable due to slight variations over time resulting from the nature of the injury.
We note the submission concerning potential assessment of the cervical spine. The clinical findings of the Medical Assessor show that there is no assessable impairment of that body part. Accordingly, the issue of causation does not need to be addressed.
We note the two incidents following the motor accident referenced in the history obtained by Medical Assessor Oates. On the history provided, the second accident provided a short-term exacerbation of symptoms whilst the first incident did not affect the relevant body parts. Accordingly, there is no basis to make any deduction pursuant to cl 6.34 for these incidents.
The impairment of the brachial plexus and the left shoulder is stabilised and permanent within the meaning of cls 6.19 and 6.20 of the Guidelines due to the duration of and the consistency of symptoms over an extended period. There is no suggestion of treatment in the future that would affect our findings. Based on the clinical experience of the Medical Assessors on the Panel, we do not expect any change in impairment over the next 12 months.
CONCLUSION
The impairment of 11% is different from that assessed by Medical Assessor Kenna. Accordingly, the medical assessment certificate is revoked, and a new medical assessment certificate is issued.
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