Session IV - Foot & Ankle

Fri., 10/6/06 Foot & Ankle, Paper #25, 11:00 am

Comparison of a Gravity Stress Examination and a Manual Stress Examination in the Determination of Supination-External Rotation Ankle Fracture (44-B) Subtype in the Acutely Injured Patient

Harold Schock, MD (n); Michael S. Pinzur, MD (n);
Leslie M. Manion, RN (n); Michael D. Stover, MD (n);
Loyola University Medical Center, Maywood, Illinois, USA

Purpose: The supination-external rotation injury pattern, a 44-B fibula fracture, is the most common indirect ankle fracture. The distinction between 44-B subtypes that do and do not have medial injuries is important in determining the need for operative stabilization. The gravity stress view has been described in a cadaveric model to diagnose medial ligament injuries, while a manual stress view is considered the gold standard. The purpose of this study is to evaluate the efficacy of a gravity stress examination relative to a manual stress examination in determination of 44-B subtype in the acute setting.

Methods: We prospectively evaluated all 44-B fibula fractures presenting to the emergency department and outpatient center. After diagnosis of a 44-B fibula fracture without widening of the medial clear space or a medial malleolar fracture on initial radiographs, patients were examined with a gravity stress view radiograph followed by a manual stress view radiograph. Visual analog scale (VAS) scores were obtained prior to and following gravity stress and manual stress examinations. Standard criteria were used to evaluate radiographs as stress-positive or stress-negative.

Results: Twenty patients were enrolled. Examinations were stress-positive if there was >4 mm of medial clear space widening that was also 1 mm greater than the superior clear space on either stress examination. Ten patients were stress-positive with a medial clear space measuring 5.81 mm (± 1.72) on gravity-stress and 5.64 mm (± 2.05) on manual stress examinations. Ten patients were stress-negative with a medial clear space measuring 3.97 mm (± 0.94) on gravity stress and 3.61 mm (± 0.84) on manual stress examinations. There was a statistically significant difference (P = 0.000007) in VAS score increase from pretesting to gravity stress testing compared to VAS score from pretesting to manual stress testing. Increase from pretesting to gravity stress testing was 0.6 (± 0.82) and from pretesting to manual stress testing, 3.25 (± 1.99). Two manual stress examinations were false negative. There were no false negatives in the gravity stress group.

Conclusion/Significance: Gravity stress examinations were found to be as reliable as manual stress examinations in the diagnosis of medial ligament injuries in association with 44-B type fibula fractures. Patients perceived the gravity stress examination as more comfortable than the manual stress examination. The data suggest that the gravity stress examination may be able to replace the manual stress examination as a screening examination in the diagnosis of these injuries.

If noted, the author indicates something of value received. The codes are identified as a-research or institutional support; b-miscellaneous funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts disclosed, and *disclosure not available at time of printing.
· The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an "off label" use). · · FDA information not available at time of printing.