The recent Personal Injury Commission decision of Member Diana Benk of Shanks v Secretary, Department of Planning, Industry and Environment [2024] NSWPIC 499 (Shanks)1 showcases how whole person impairment can be aggregated across multiple injuries.
What is aggregation
Aggregation refers to calculating the whole person impairment (WPI) of an injured worker by aggregating or combining the impairment from more than one injury.
Why aggregation is important
Aggregation is significant because whole person impairment is very important in determining an injured worker’s rights under the NSW workers compensation system.
Various entitlements for an injured worker are impacted solely by the level of WPI.
Some of the ways an injured worker’s claim are impacted by the level of WPI include:
• Time frames for treatment 2
• Access to domestic assistance 3
• Work capacity decisions 4
• Access to lump sum entitlements 5
• Access to a work injury damages claim 6
When you can’t aggregate
There are some situations where aggregation is not possible.
If any injured worker has a physical injury and then later develops a secondary psychological condition, any impairment for the secondary psychological injury cannot be aggregated7.
If an injured worker has a physical injury and a primary psychological injury in the same accident, they cannot aggregate these impairments together. The injured worker can only claim the higher WPI of the two8.
The recent decision of Bell v The Mining Pty Ltd [2024] NSWPICPD 359 indicates a similar approach to the above occurs when there is a primary psychological injury and a secondary physical condition; only the higher WPI of the two can be claimed.
When you can aggregate
The most obvious example of aggregation is if an injured worker sustains multiple physical injuries in the one accident event; the impairments that flow from these injuries can be aggregated10.
A further example is derived from a case of Department of Juvenile Justice v Edmed [2008] NSWWCCPD 6 (18 January 2008) (Edmed)11. This case provides that if an injured worker has two or more separate dates of injury and the injuries result in the ‘same’ or ‘one pathology,’ the injuries can be aggregated to give a combined whole person impairment.
Relatively recently there have been two important court of appeal decisions of Secretary, Department of Education v Johnson12(Johnson) and Ozcan v Macarthur Disability Services Ltd13(Ozcan) dealing with the topic of aggregation of WPI. Both cases involved aggregation of multiple dates of injury as in Edmed but, unlike Edmed, did not involve the same or one pathology.
In finding that the injuries could be aggregated for WPI purposes, Johnson and Ozcan referred to and relied on the common law principles of causation of State Government Insurance Commission v Oakley14 (Oakley).
The Oakley principles are as follows:
“There are three possible categories where an earlier injury is followed by a later injury, as follows:
• Where the later injury results from a subsequent accident that would not have occurred had the victim not been in the physical condition caused by the earlier accident, the second injury should be treated as having a causal connection with the earlier accident.
• Where an earlier injury is exacerbated by a subsequent injury, there will be a causal connection between the original injury and the subsequent damage unless it can be shown that some part of the subsequent damage would have been occasioned even if the original injury had not occurred.
• Where a victim, who had previously suffered an injury, suffers a subsequent injury and the subsequent injury would have occurred whether or not the victim had suffered the original injury and the damage sustained by reason of the subsequent injury includes no element of aggravation of the earlier injury, there will be no causal connection between the original injury and the damage subsequently sustained.”
In both Johnson and Ozcan, the Court accepted that the second category described in Oakley applied for aggregation of impairment. Johnson saw the aggregation of two psychological injury claims to achieve a WPI of 19%. Ozcan saw the aggregation of impairments from three separate physical injury claims resulting in WPI of 15%.
Importantly in Ozcan, the Court was satisfied the
“… impairments are however connected because the first incident injuries materially contributed to them. They therefore “arose out of” and “resulted from” that incident. The likelihood of the consequences of multiple accidents needing to be assessed together is considerable in light of the law’s adoption of a “material contribution” rather than a “sole cause” test.” 15
The facts in Shanks16
On 2 September 2021 (2021 injury) Ms Shanks sustained an injury to the left knee. Consequential conditions to the right knee and lumbar spine were claimed and ultimately accepted
As part of the treatment and recovery, Ms Shanks had anterior cruciate ligament reconstruction (ACL) surgery.
After returning to work, Ms Shanks on 7 April 2022 (2022 injury), whilst walking down a flight of steps in the course of her employment, she sustained another injury to her left knee.
There was no question that the two accidents caused two different pathologies to Ms Shanks’ left knee.
Ms Shank’s Independent Medical Examiner (IME) Dr Soo explained her “… injuries to the left leg in 2021 and then in 2022 were NOT of the same pathology. The first injury was a multi-ligament knee injury. The second injury was a tibial plateau fracture....” 17
Dr Soo went on to note “The injury in 2022 occurred due to the physical condition the client was in from her 2021 injury… Ms Shanks suffered a multi ligament injury to the left knee at work on the 2nd September 2021 that required surgical reconstruction of her anterior cruciate ligament. Unfortunately whilst she was recovering and rehabilitating her knee following the surgery, she suffered a second fall whilst at work resulting in an undisplaced tibial plateau fracture in the same leg. Subsequently as a result of this second fall her rehabilitation was set backwards and due to a long period of altered gait and overcompensation she has further aggravated her lower back and her right knee.” 18
A WPI claim was made aggregating the WPI across the 2021 injury and 2022 injury dates relying on the principles in Oakley applied in Johnson and Ozcan.
Proceedings before the Personal Injury Commission
The whole person impairment claim proceeded to determination as the insurer disputed the ability of Ms Shanks to aggregate the WPI. The focus of the insurer’s position seemed to be on how the aggregation principles in Edmed did not apply.19
Member Benk however determined Ms Shanks’ injuries could be aggregated accepting that:
“… the treating medical evidence demonstrates the initial work injury had not resolved prior to the second injury and the respondent’s contention the applicant’s initial injury had resolved is quashed by the contemporaneous evidence which establishes the applicant was still in the recovery phase of her initial injury and the ACL reconstruction…”20
The Member noted that not only Ms Shanks’ qualified IME, Dr Soo, but the insurer IME Dr Nair, found that the 2021 injury had not ceased at the time of the 2022 injury.21
The Member went on to record:
“... the medical evidence summarised above reveals that the second injury has caused an element of aggravation of the earlier injury (particularly with regards swelling and aggravation of the existing osteoarthritis) and suggests the damage sustained was greater because of aggravation of the earlier injury and the impacts of the surgery to address that injury. I therefore find, the additional damage resulting from the aggravated injury should be causally connected to the original injury.”22
Finally, the Member confirmed the second limb of Oakley applied stating:
“I am satisfied that injury was a material factor in contributing to the damage that the applicant sustained in the injury on 7 April 2022 and so find the applicant’s injury could be categorised within the second limb of Oakley, as although it would have occurred had she been in normal health, the damage she sustained had been greater because of aggravation of her initial work injury…”.23
Aggregation of different injuries for calculation of WPI does not come up to all too often given the relatively narrow set of facts that are required to exist. Principal Member John Harris found Oakley applied in Griffiths v Secretary, Department of Education [2022] NSWPIC 22024 as did Member Elizabeth Beilby in Brown v S & A Trailers Pty Ltd25 but otherwise determinations are few and far between.
Whilst relatively infrequent, given the importance of WPI for determining rights for injured workers in NSW, it is vital the application of the Oakley principles are not overlooked when applicable.
If you have a workers compensation claim and need advice concerning your rights under the workers compensation legislation please reach out to us.
(1) https://www8.austlii.edu.au/cgi-bin/viewdoc/au/cases/nsw/NSWPIC/2024/499.html
(2) s59A of the Workers Compensation Act NSW 1987
(3) s60AA of the Workers Compensation Act NSW 1987
(4) s38(3) of the Workers Compensation Act NSW 1987
(5) s66(1) of the Workers Compensation Act NSW 1987
(6) S151H of the Workers Compensation Act NSW 1987
(7) S 65A (1) of the Workers Compensation Act NSW 1987
(8) S 65A (4) of the Workers Compensation Act NSW 1987
(9) https://www8.austlii.edu.au/cgi-bin/viewdoc/au/cases/nsw/NSWPICPD/2024/35.html
(10) s 322(3) of the Workplace Injury Management and Workers Compensation Act 1998
(11) https://www8.austlii.edu.au/cgi-bin/viewdoc/au/cases/nsw/NSWWCCPD/2008/6.html
(12) [2019] NSWCA 321
(13) [2021] NSWCA 56
(14) (1990) 10 MVR 570 at 573
(15) Para 18
(16) http://www7.austlii.edu.au/cgi-bin/viewdoc/au/cases/nsw/NSWPIC//2022/220.html
(17) Para 12
(18) Para 12
(19) Para 19
(20) Para 27 (b)
(21) Para 27 (c)
(22) Para 28
(23) Para 29
(24)http://www7.austlii.edu.au/cgi-bin/viewdoc/au/cases/nsw/NSWPIC//2022/220.html
(25) https://www.pi.nsw.gov.au/__data/assets/pdf_file/0011/902999/2251-20-Brown-COD-SOR.pdf
