Subtalar Distraction Bone Block Fusion: An Assessment of Outcome

Twenty-nine feet in 28 patients who underwent subtalar distraction bone block fusion for the treatment of subtalar deformities associated with symptomatic arthrosis were evaluated. All patients were assessed with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale score. Eighteen men and 10 women with a mean age of 44 years were evaluated. The mean follow-up was 33 months. Subtalar arthrosis was secondary to trauma in 27 of 29 feet (93%) with os calcis fractures in 19, subtalar dislocations in 5, and talus fractures in 3. Eighteen of the 28 patients (64%) returned to either full- or part-time work. The change in the mean AOFAS Ankle-Hindfoot Scale score from 25 preoperatively to 75 postoperatively was statistically significant ( P < 0.0001). The radiographic analysis of the pre- and postoperative standing lateral radiographs showed an average increase of 8 mm in hindfoot height, 9° in lateral talocalcaneal angle, and 11° in lateral talar declination angle that were statistically significant ( P < 0.0001). All patients but one (96%) were satisfied. Complications included four nonunions, two varus malunions, one metatarsal stress fracture, and one medial plantar nerve paresthesia. Each nonunion occurred in patients who smoked.