The use of subtalar arthroscopy in open reduction and internal fixation of intra-articular calcaneal fractures.

Congruency of the subtalar joint is a major predictor of outcome after intra-articular calcaneal fractures. Because of the irregular shape of the posterior joint facet, minor steps may be overlooked with direct vision or intra-operative fluoroscopy during open reduction and internal fixation (ORIF). In a preliminary series of 15 subtalar arthroscopies during hardware removal after ORIF of intra-articular calcaneal fractures, patients with visible steps of 1 mm or more had significantly inferior functional results compared to those with an intact subtalar joint (117 vs. 158 points with the 200-point score, 71.3 vs. 91.2 points with the Maryland Foot Score, P<0.01). Congruency of the posterior facet was controlled arthroscopically in 47 intra-articular calcaneus fractures after open reduction and temporary K-wire-fixation. In 12 cases (25.5%), despite seemingly correct reduction as judged fluoroscopically, incongruencies in the posterior calcaneal facet were detected and reduction was repeated, temporarily removing the K-wires. After anatomical reduction a standard AO calcaneal plate was fixed to the lateral wall. Intra-operative arthroscopy appears to be useful in detecting minor incongruencies after ORIF of intra-articular calcaneus fractures. In the hands of an experienced surgeon it is less time demanding than intra-operative X-rays and more precise than fluoroscopy.