RESUMO
Background. There has been historical debate as to whether the distal tibiofibular syndesmosis can be overtightened during operative fixation. We used finite-element analysis to determine if overtightening of syndesmotic screws can cause widening of the lateral gutter clear space in the ankle joint. Methods. A 3D finite-element model was constructed and analyzed using geometries from a computed tomography scan of a cadaveric lower leg. Starting 2 cm from the plafond, screw fixation was simulated at 5-mm increments to a distance of 5 cm from the plafond. The fibula was compressed 2 mm toward the tibia at each interval, and the change in distance between the lateral talus and distal fibula was measured. Results. Medial deflection of the fibula resulted in widening of the lateral clear space, which was proportional to the amount of deflection. The effect increased as screws were placed closer to the plafond, with 1.5 mm of widening at 2 cm (0.76 mm/mm) versus 0.7 mm at 5 cm (0.34 mm/mm). Conclusion. Our finite-element model demonstrated that overtightening of the distal tibiofibular syndesmosis with medial fibular displacement can cause widening of the lateral clear space. Clinical relevance. The results suggest that screws placed farther from the plafond widen the lateral clear space to a lesser degree, which may be advantageous during surgical fixation to prevent clear space widening and increased tibiotalar contact forces.Levels of Evidence: Level I.
Assuntos
Fraturas do Tornozelo/cirurgia , Traumatismos do Tornozelo/cirurgia , Articulação do Tornozelo/cirurgia , Parafusos Ósseos , Fíbula/cirurgia , Fixação Interna de Fraturas/métodos , Tíbia/cirurgia , Fenômenos Biomecânicos , Cadáver , Fíbula/patologia , Análise de Elementos Finitos , Humanos , Tálus/patologia , Tálus/cirurgia , Tomografia Computadorizada por Raios XRESUMO
Distal triceps ruptures are uncommon injuries resulting in loss of elbow extension strength and necessitating surgical repair to ensure optimal functional outcome. Traditional fixation techniques using running, locking sutures through the tendon secured through bone tunnels have been shown to poorly restore the anatomic footprint and are mechanically inferior to anatomic repairs. We endorse restoring the anatomic footprint of the distal triceps, similar to the well-researched rotator cuff repair model.
