Fractures of the sustentaculum tali.

OBJECTIVE: Anatomical reconstruction of displaced sustentaculum tali fractures via a direct medial approach.

INDICATIONS: Displaced fractures of the sustentaculum tali with incongruity or depression of the medial facet of the subtalar joint, entrapment of the flexor hallucis longus or flexor digitorum longus tendons, fracture line extending into the posterior facet of the subtalar joint.

CONTRAINDICATIONS: Infected or grossly contaminated soft tissue, severely restricted vascular supply to the foot, high perioperative risk.

SURGICAL TECHNIQUE: Direct medial approach over the sustentaculum tali, retraction of the tendons, joint exploration, fracture reduction using the medial facet and cortical outline as guidelines, fracture fixation with two small fragment screws from medial to lateral directed slightly plantarly and posteriorly. Fractures with depression of the medial facet as a whole can alternatively be reduced and fixed percutaneously.

POSTOPERATIVE MANAGEMENT: Lower leg splint for 5-7 days, partial weight-bearing with 20 kg for 6-8 weeks (until radiographic signs of consolidation) in the patient's own shoewear, early range of motion exercises of the ankle, subtalar and mid-tarsal joints.

RESULTS: Over a course of 15 years, 31 patients were treated operatively for sustentacular fractures. In all, 27 patients (87%) had additional fractures to the same foot and ankle. Eighteen patients with a mean age of 41 years treated at our institution with screw fixation for a unilateral fracture of the sustentaculum tali could be followed for a mean of 80 months (range 15-151 months). No wound healing problems or infections were seen with the medial approach. At the time of follow-up, 15 sustentaculum tali fractures had an average Foot Function Index of 21.6 and an average AOFAS Ankle-Hindfoot Score of 83.6. Patients with isolated fractures of the sustentaculum tali had significantly better scores than those with additional injuries. In 1 patient, an additional lateral process fracture of the talus required subtalar fusion due to persistent pain. Care must be taken not to overlook these atypical calcaneal fractures and accompanying injuries to the mid-tarsal joint and the lateral talar process as seen in 45% and 23%, respectively, in the present series.