Stability of the offset V-osteotomy. Test jig development and saw bone model assessment

In the offset V-bunionectomy used for hallux valgus repair, both the Kalish and the Vogler variations have a long dorsal arm, but the apex is more distal in the Kalish procedure. This study investigated the effect that pin orientation and location of the osteotomy apex have on weightbearing stability. The authors studied saw bone models that were loaded to failure in an Instron 4201 materials testing machine and, in addition, designed, fabricated, and used a unique jig assembly to help minimize data variability. Statistically significant differences were found between the surgical techniques and pin orientations: the Kalish osteotomy was stronger than the Vogler procedure, and in both osteotomies, the plantarly directed Kirschner wire orientation was stronger than the dorsally directed orientation.