The effect of calcaneal osteotomy on contact characteristics of the tibiotalar joint

Abstract

To investigate the effect of calcaneal osteotomy on tibiotalar joint contact patterns in a normal and a flatfoot model, we axially loaded 11 fresh frozen cadaver legs with 700 N and quantified tibiotalar joint contact characteristics using Fuji superlow pressure film. For each testing sequence, the unconstrained foot was loaded in neutral, 10° dorsiflexion, and 10° plantarflexion. Tibiotalar joint loading was performed both with a materials tester (Group 1) and manually using a customized jig (Group 2). After calcaneal osteotomy, the calcaneus was translated medially or laterally by 10 mm, and the testing sequence was repeated. Each of these testing series was then repeated on a flatfoot model simulated by soft-tissue sectioning. Images were analyzed using a Bioquant R Video system for Group 1 and an Orthographics Digitizing Tablet for Group 2. For Group 1, there was no difference in the quantitative tibiotalar joint contact characteristics with the exception of all parameters evaluated with the foot in plantarflexion ( P = 0.062). For Group 2, in the normal foot, a lateral translational osteotomy had no effect, but a medial translational osteotomy was associated with a change in the tibiotalar contact ( P = 0.05). The flatfoot model (Group 2) was associated with a qualitative shift of pressure laterally and a quantitative alteration of the contact area in all positions when compared to the normal ankle ( P = 0.06). A medial translational osteotomy altered this contact area ( P = 0.001). We concluded that hindfoot alignment can adversely affect tibiotalar joint contact characteristics. A calcaneal osteotomy may be a useful alternative to tibiotalar arthrodesis in cases of early tibiotalar arthritis secondary to severe varus or valgus hindfoot deformity.