Displaced fractures of the os calcis involving the subtalar joint: the key role of the superomedial fragment.

Fourteen displaced intra-articular fractures of the os calcis are reviewed following open reduction and internal fixation using a lateral approach with an average follow-up of 22 months (range, 12 to 44 months). Postoperative management consisted of early subtalar motion with delayed weightbearing. Twelve of 14 fractures were considered good results on the basis of no pain, 50% normal subtalar motion, and near-normal anatomy. Pain correlated with incomplete reduction of the superomedial fragment and, thus, incongruent reduction of the posterior facet in two cases. The importance of effecting a reduction of the superomedial border of the os calcis is emphasized.