Abstract
Introduction
The strength of the Scarf osteotomy has been compared to that of other metatarsal osteotomies, but the effect of increasing the amount of displacement is unknown. The purpose of this study was to determine whether increasing offset adversly affects the strength of the Scarf osteotomy.
Methods
Seven pairs of freah frozen cadaveric feet were tested. Specimens in Group 1 underwent Scarf osteotomy with displacement of one third the mid shaft diameter. Specimens in Group 2 were offset two thirds the midshaft diameter. All osteotomies were fixed using two Barouk screws.
Each specimen was tested in cantilever bending using a servohydraulic testing machine.
Results
There was no statistically significant difference in strength or stiffness between the two groups. Mean strength was 75.2 N ± 16.8 for Group 1 and 64.8 N ± 28.7 for Group 2 (p> 0.05).
Mean stiffness was 12.9 N/mm ± 5.1 for Group I and 10.2 N/mm ± 5.9 for Group 2 (p> 0.05).
Discussion
All specimens failed at the proximal extent of the osteotomy. Failure did not occur by screw pullout in either Group. The proximal part of the cut is therefore the weakest part of the construct irrespective of the degree of osteotomy displacement.
The abstracts were prepared by Mr J. L. Barrie. Correspondence should be addressed to Mr J. L. Barrie, BOFSS Editor, Department of Orthopaedic Surgery, Blackburn Royal Infirmary, Blackburn, Lancashire BB2 3LR.