Explorative study of the sensitivity and specificity of the pronator quadratus fat pad sign as a predictor of subtle wrist fractures

Fallahi, Farshid, Jafari, Hooman, Jefferson, Gail, Jennings, Peter and Read, Ruth (2012) Explorative study of the sensitivity and specificity of the pronator quadratus fat pad sign as a predictor of subtle wrist fractures. Skeletal Radiology, 42 (2). pp. 249-253.

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Abstract

Objective: To investigate the value of post-traumatic pronator quadratus (PQ) fat pad sign as a reliable predictor of subtle wrist fractures.

Materials and methods: This was a prospective study of 68 patients undergoing X-ray for traumatic wrist injuries and subsequent MRI. The reliability of a positive PQ fat pad sign on X-ray, defined as either raised, interrupted or obliterated, was evaluated in detection of subtle wrist fractures.

Results: Out of 68 patients, 28 had a positive PQ sign without any obvious bony injuries on plain radiographs; of these, the PQ fat pad was obliterated in 11, disrupted in 12, and raised in five cases. Fractures defined as cortical interruption or trabecular fractures were revealed in 13/28 (46 %) patients with a positive PQ sign but only in 7/40 (18 %) patients with a negative sign. With regards to different types of abnormal PQ fat planes, fractures were present in 7/12 patients with a disrupted plane (58 %), 6/11 patients with an obliterated plane (54 %), and none of the patients with a raised plane. The overall sensitivity and specificity of a positive PQ sign in the prediction of occult wrist fractures were 65 and 69 %, respectively.

Conclusions: Our findings indicate that a positive pronator quadratus (PQ) fat pad sign is not a reliable predictor of subtle fractures of the wrist, although we believe that it is a useful radiographic sign in justifying MRI for further clarification of possible joint abnormalities including occult fracture and cortex interruption.

Item Type:	Article
Journal / Publication Title:	Skeletal Radiology
Publisher:	Springer Verlag (Germany) for International Skeletal Society
ISSN:	0364-2348
Departments:	Academic Departments > Medical & Sport Sciences (MSS) > Health and Medical Sciences
Additional Information:	© The Author(s) 2012. This article is published with open access at Springerlink.com.
Depositing User:	Anna Lupton
Date Deposited:	08 Feb 2017 14:09
Last Modified:	12 Jan 2024 11:00
URI:	https://insight.cumbria.ac.uk/id/eprint/2660

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