Summary

The “Z” lengthening osteotomy is a safe and effective procedure with reproducible and excellent medium-term results.

Abstract

Objective

To analyze the clinical outcomes of the “Z” lengthening osteotomy of the fibula to correct a widened mortice of the ankle after fracture. Methods 5 patients (5 feet) who underwent a “Z” lengthening osteotomy between Septempter 2009 and February 2011 were prospectively reviewed. There were all males. Ages ranged from 26 to 73 years (mean 49.7 years). The interval between trauma and operation ranged from 5 to 33 months (mean 13.2 years). Indications for surgical repair included extramalleolus displacement, fibular shortening more than 4 mm, obviously ankle instability. A fibularoleteral incision was taken. The Z lengthening osteotomy was performed by oscillating saw at 8cm above the tip of the fibula, and then lengthened the fibular by 4-12 mm. The fragments were fixed with a 1/3 fibular plate or 2 interfragmental compression screws. At preoperatively, 3, 6, and 12 months postoperatively patients completed AOFAS scores, repeat radiographic assessment (AP and lateral, and sprung mortice views). Results All were followed up for 6 to 55 months (mean, 21.5 months), which were proved be bone union by clinical exam and radiology. The sprung mortice view shows: a perfectly equidistant and parallel joint space; the contour of the dense subchondral bone can be followed over the distal tibiofibular joint; the contour of the fibular part of the articular surface doesn’t lie more proximal. American Orthopedic Foot and Ankle Society (AOFAS) scores improved from a preoperative mean of 70.17±8.21 and increased significantly to 75.58±12.49 after 6 months, and to 90.58±8.45 at final follow-up. All of these changes were significant. Conclusion The “Z” lengthening osteotomy is a safe and effective procedure with reproducible and excellent medium-term results.
Key words: ankle joint; instability; fibular; lengthen