News and Insights

Lower Limb impairment assessment – so we are adding impairments now?

It is a trite observation that AMA Guides are complex instruments to interpret and apply.

The recent Supreme Court decision of Arik v Vicinity Centres PM Pty Ltd [2023] VSC 94 is an example of this.

How does this case affect impairment assessments?

Background

• The case involves a plaintiff who sought compensation from the owner and manager of the shopping centre, where she slipped and sustained injuries to her lower back and right hip.
• Under Part VBA of the Wrongs Act 1958 (Vic), she can only recover damages for non-economic loss if she suffered a ‘significant injury’ as a result of her fall. This requires a whole person impairment assessment.
• There was a referral to the Medical Panel to determine whether the degree of impairment resulting from the physical injury satisfied the threshold level.
• The Medical Panel determined that the plaintiff did not suffer the requisite impairment level for ‘significant injury’.
• The plaintiff sought judicial review of the Panel’s determination, on the ground that the Panel did not assess her degree of impairment in accordance with the American Medical Association’s Guides to the Evaluation of Permanent Impairment (Fourth Edition) (“the Guides”).
• The key issues before the court was whether the Panel correctly applied the range of motion table when assessing the right hip whole person impairment.
• Section 3.2e of the Guides contains tables for several lower extremity parts such as knee, ankle, hip, hindfoot and toe.
• Table 40 is relevant to the hip motion impairments.

Table 40. Hip Motion Impairments.

• The Panel’s measurement revealed a mixture of mild to moderate restrictions for different motions. In assessing the whole person impairment, the Panel  selected the highest impairment from the most severe deficit. The plaintiff was given the rating of “moderate”, which equates to a 4% whole person impairment.
• The plaintiff argued that the Panel was wrong to assess the degree of impairment of her hip by taking the highest rating of the range of motion deficits on examination. Instead, she submitted, the Panel was required by Section 3.2 of the Guides to combine the measured whole-person impairment percentages for each range of motion. By combining the whole person impairment percentages for each range of motion, this produced a total whole person impairment percentage of 14%, which is above the “threshold level’ of more than 5%.
• It is helpful to have regard to the table below, which sets out the individual impairments that adds up to 14%.

Decision

Justice Richards concluded that the Medical Panel did not assess the plaintiff’s degree of impairment in accordance with the Guides. It should have combined the whole person impairment estimates for the several range of motion restrictions it measured in the right hip, rather than determining her degree of impairment by taking the highest rating. This amounted to a jurisdictional error.

Her Honour reached her conclusion, by having regard to the introduction of Section 3.2 which states “If the patient has several impairments of the same lower extremity part, such as the leg, or impairments of different parts, such as the ankle and toe, the whole-person estimates for the impairments are combined”; the purpose of the Guides; and the other editions of the AMA Guides.

Implication of this case

This case affects lower limb injuries, where the assessor has selected the range of motion method to assess the impairment. Instead of selecting the highest impairment, you add the whole person impairment estimates for individual range of motion restrictions. The range of motion tables cover the following body parts: hip, knee, ankle, hindfoot and toe. It is important to note that not all lower limb claims are evaluated using such method.

Is this the right interpretation of the Guides? Watch this space!