THE EFFECT OF DIFFERENT GEOMETRIC CONFIGURATIONS OF THE WEIL OSTEOTOMY ON PLANTAR PRESSURE IN AN IN VITRO CADAVER MODEL.

Abstract

The Weil osteotomy has gained popularity for surgically treating patients with metatarsalgia, intractable plantar keratosis and/or metatarsophalangeal joint dislocation because of its simplicity and lack of complications. Different geometric configurations of the Weil osteotomy have been proposed to reduce plantar pressure. In a dynamic cadaver model, these different geometric configurations of the Weil osteotomy did not significantly alter plantar pressure. Metatarsal head resection was required to significantly reduce plantar pressure.

The purpose of this study was to evaluate the effect of different geometric configurations of the Weil osteotomy on the plantar pressures in a dynamic cadaver model.

Different geometric configurations of the Weil osteotomy have been proposed to decrease plantar pressure, but in a dynamic cadaver model, these modifications did not significantly alter plantar pressure. Metatarsal head resection was required to significantly reduce plantar pressure.

The plantar translation of the metatarsal head occurring with a more oblique Weil osteotomy compared to a standard Weil osteotomy did not significantly increase plantar pressure in a dynamic cadaver model. The addition of a 4 mm slice resection did not significantly reduce pressure. Metatarsal head resection was required to significantly reduce pressure (p=0.02).

Ten specimens (5 matched pairs of cadaver lower extremities) were tested. Each pair of specimens had an oblique Weil osteotomy performed on one side, and a standard (parallel) Weil osteotomy on the other. Then, a 4 mm slice resection, and metatarsal head resection were performed sequentially. The plantar pressures were measured with an F scan in-shoe sensor while cyclically loaded to 700 N at a frequency of 1 Hz in intact specimens, and after each intervention.

The different geometric configurations of the Weil osteotomy did not significantly alter plantar pressure; metatarsal head resection was required to significantly reduce pressure. The Weil osteotomy reliably reduces dislocated metatarsophalangeal joints. The angle of the osteotomy does not affect plantar pressure. Further study in a dynamic model is required to identify other factors, which affect plantar pressure.