OBJECTIVETo study the feasibility and clinical efficacy of a minimally invasive sinus tarsi approach in the treatment of Sanders II calcaneus fractures.

METHODSFrom August of 2015 to July of 2016, 13 patients(totally 13 feet) with Sanders II intra-articular calcaneus fractures were treated via the minimally invasive sinus tarsi approach. The Böhler angle, Gissane angle and the length, width and height of calcaneus were compared between pre-operation and post-operation. The AOFAS ankle and foot scoring system of the orthopaedic ankle foot Association was used to evaluate the efficacy.

RESULTSAll the patients were followed up, and the duration ranged from 6 to 15 months, with an average of 9.5 months. No incision complications occurred. The Böhler angle was increased from preoperative (18.82±5.11)° to postoperative(26.63±4.45)°(=-4.16,=0.000). The Gissane angle was increased from preoperative(111.07±15.36)° to postoperative (124.56±8.71)° (=-2.75,=0.011). The length, width, height of calcaneus were absolutely improved from preoperative(69.82±5.95) mm, (42.07±3.68) mm, (41.20±3.90) mm to preoperatively(72.61±5.46) mm, (39.10±4.02) mm, (44.03±3.33) mm. According to the AOFAS, 8 patients got an excellent result, 4 good and 1 poor, and the postoperative mean score was 88.2±5.9.

CONCLUSIONSThe limited open sinus tarsi approach could be used successfully to treat displaced Sanders II fractures with less injury and effectively restored the surface of subtalar joint, however the method is not fit for the patients with comminuted fracture in lateral wall and great change in the length, width, height, varus and valgus of calcaneus.