Percutaneous subtalar joint screw fixation of comminuted calcaneal fractures: a salvage procedure

Introduction Malunited comminuted calcaneal fractures result in poor function due subtalar joint arthritis and altered biomechanics. We aimed to assess whether percutaneous subtalar joint screws after fracture reduction provide good outcomes for these difficult injuries. Methods We retrospectively analysed 15 comminuted calcaneal fractures (in 14 patients) treated with percutaneous subtalar screw fixation. All patients had a minimum of 12 months' follow-up. Six patients had open injuries. On the preoperative and the latest postoperative radiograph, Bohlers angle, Gissane angle, calcaneal inclination, width and length, absolute foot height, and posterior facet height were measured. Preoperative computed tomography scans were used to classify the fractures by Sanders classification. Clinical outcome scores were recorded postoperatively. Results Mean age was 34.2 +/- 14.2 years. Minimum follow-up was 12 months (mean 17.2 +/- 4.4 months). Nine patients had a Sanders 4, 3 had a Sanders 3AB, 2 had a Sanders 3BC, and 1 had a Sanders 3AC fracture. Eighty percent of patients had their angle of Gissane, absolute foot height, calcaneal length and inclination restored by this technique. Bohlers angle was restored back into the normal range in 54% of patients. Mean postoperative AOFAS score was 74 +/- 11. AOFAS scores positively correlated with postoperative Bohlers angle (Pearson's correlation coefficient 0.85; p = 0.004). One patient (7%) had a wound breakdown postoperatively and three patients (20%) had heel pain from the screws, which improved after removal. Conclusion Percutaneous subtalar screws offer a reliable option to restore calcaneal anatomy in comminuted calcaneal fractures, with low complication rates. Over 80% of patients had their angle of Gissane, calcaneal length and inclination restored, and over 50% of patients had all radiological parameters restored by this technique. It offers the benefits of percutaneous reduction and fixation and this procedure may be considered an effective first stage prior to definitive subtalar fusion. Further work is needed to review the longer-term outcomes and the conversion rate to arthrodesis.