Medial Malleolar Osteotomy: The Influence of 2 Types of Osteotomies and 2 Fixation Methods on Articular Displacement in Fresh-Frozen Cadaveric Specimens.

Abstract

The medial malleolar osteotomy is required in some cases of osteochondral lesions, bone tumors, and fractures of the medial talar dome for surgical access. The literature is uncertain about which type of osteotomy and fixation is best. The objective of this study was to compare, in cadaveric specimens, the oblique and chevron medial malleolar osteotomies and their fixation with either 2 or 3 screws, evaluating the possibility of articular displacement. We hypothesize that the chevron osteotomy results in a lower chance of articular displacement at the end of the procedure than the oblique osteotomy. Our second hypothesis is that fixation with 3 screws also reduces the risk of articular displacement compared with 2 screws. Forty anatomical fresh‑frozen specimens were analyzed and divided into 4 groups (10 per group): oblique osteotomy fixed with 2 or 3 screws and chevron osteotomy fixed with 2 or 3 screws. One fracture occurred in the chevron osteotomy group with 3 screws, leaving 39 specimens for analysis. After osteotomies and fixation, the talus was removed, and articular displacement (step‑off) of the distal tibia was assessed using a digital caliper. The results indicated a lower incidence of articular displacement in chevron osteotomy (21.1%) compared with oblique osteotomy (50%). Fixation with 3 screws showed a lower rate of incongruence (21.1%) compared with 2 screws (50%). When the type of osteotomy and fixation were combined the chevron osteotomy fixed with 3 screws had no measurable articular displacement in this cadaveric model. In this cadaveric surgical technique model, a chevron medial malleolar osteotomy fixed with 3 screws showed no measurable articular displacement and overall had a lower risk of articular step‑off compared with oblique osteotomy and 2‑screw fixation.