Medical assessor guidance note 4

Musculoskeletal System: Impairment of the Pelvis

Assessment of pelvic fractures

This material is issued by the Motor Accidents Authority under s.65(2) of the Motor Accidents Compensation Act 1999 (the Act) in the interests of promoting accurate and consistent medical assessments under the Act. The interpretation provided here is not legally binding but represents the clinically recommended interpretation in an area where more than one interpretation of existing provisions may be possible. This recommended interpretation is publically available. Any medical assessment which does not adopt this interpretation should be accompanied by clinical justification for the interpretation adopted, supported by full, robust reasons.


  • The Motor Accidents Authority Permanent Impairment Guidelines – Guidelines for the assessment of permanent impairment of a person injured as a result of a motor vehicle accident 1 October 2007 (MAA Guidelines): Chapter 4 Spinal Impairment Clause 4.43, page 28.
  • The American Medical Association Guides to the Evaluation of Permanent Impairment, 4th Edition (AMA 4 Guides): Chapter 3 section 3.4 page 131, The Pelvis


The AMA 4 Guides prescribe a different impairment rating for fractures of the pelvis, depending upon whether residual signs are present or not. The presence of residual signs can make a significant difference to the impairment rating (e.g. whole person impairment (WPI) increases from 0% to 5% for displaced fractures of bilateral rami, from 0% to 10% for an ischium fracture with >1 inch displacement, and from 5% to 10% for fractures of the sacrum into the sacroiliac joint).

Issue requiring clarification

No definition of ‘residual signs’ is provided in the AMA 4 Guides or MAA Guidelines. There may be different views as to what would constitute a ‘residual sign’, which could lead to a potential for inconsistency.

Preferred interpretation

In order to distinguish between the presence or absence of residual signs, Medical Assessors should clearly state whether or not signs such as tenderness, clinically obvious asymmetry, unilateral limitation of hip joint range of motion not associated with fractured acetabulum, and/or clear evidence of mal-alignment, are present on examination. If an Assessor decides that the appropriate impairment rating is one that recognises residual signs, clear examination findings supporting this decision should be given.

Justification for preferred interpretation

In the absence of a clear definition of residual signs of pelvic fracture, it is important that Medical Assessors give a clear explanation of the factors on which their classification and impairment rating was based.

The preferred interpretation and methodology is suggested to promote consistency of assessment.

Issued by:

Injury Strategy Branch

February 2012