Distal fibula osteotomies improve tibiotalar joint compression: A biomechanical study in a cadaveric model

Background: Successful tibiotalar joint fusion relies on adequate compression. Compression following joint preparation may be affected by the extent to which the fibula holds the joint out to anatomical length. The purpose of this study was to evaluate the effect of various distal fibula osteotomies on tibiotalar joint compression. Methods: Eight adult cadaveric lower extremity specimens with an intact ankle joint and syndesmotic complex were evaluated. The ankle joint cartilage was denuded to subchondral bone. The fibula was surgically modified with three progressing procedures including an oblique fibula osteotomy, 1 cm resection, and distal fibula resection. A transducer was utilized to measure tibiotalar joint force, contact area, and peak pressure values while compressive forces of 30 N, 50 N, and 100 N were applied to the proximal tibia/fibula. Findings: Distal fibula resection significantly increased tibiotalar joint force, contact area, and peak pressure the most of all fibula conditions tested compared to intact fibula control (p <.05). Tibiotalar joint force and peak pressures were significantly increased with a distal fibula oblique osteotomy, 1 cm resection, and complete resection under both 30 and 50 N applied compressive force (p <.05). Interpretation: Complete distal fibular resection results in higher tibiotalar joint force, contact area, and peak pressure which may improve clinical rates of successful ankle fusion.