Minimally invasive surgery for Sanders type II–III calcaneal fractures with external fixator- assisted poking reduction and percutaneous screw fixation: a 2–5 years clinical and radiographic retrospective cohort study

Abstract Background: For intra-articular calcaneal fractures of Sanders type II and above, open reduction and internal fixation could obtain anatomic reduction and firm fixation, however, there are high complications associated with surgery, such as incision infection and subtalar joint stiffness. As another treatment method, poking reduction and percutaneous fixation can reduce the complications. In this study, we introduce a new technique for external fixator-assisted reduction and computer-assisted preoperative design of the poking reduction and percutaneous screw fixation.Methods: Patients with calcaneal fractures who met the inclusion criteria were treated with external fixator-assisted poking reduction and percutaneous screw fixation at our hospital from March 2017 to September 2019, and the clinical and radiographic outcomes were evaluated.Results: A total of 31 patients were followed up, 10 cases of Sanders type II, and 21 cases of Sanders type III calcaneal fracture. The mean time from injury to operation was 3.2±1.9 days; the mean hospital stay was 7.3±3.1 days; the mean operation time was 87.74±30.30 min; and the mean intraoperative blood loss was 41.45±34.16 ml. Two patients underwent a change of surgical procedure and one underwent a second operation. Postoperative follow-up radiography showed good reduction of calcaneus length, height, width, Böhler angle, and Gissane angle. Postoperative follow-up CT showed good reduction of the subtalar articular surface in 83.6% of patients. At the last follow-up, the AOFAS score was 93.84±7.92, of which 24 cases were excellent, six cases were good, and one case was acceptable. The average range of motion of flexion and extension of the ankle joint on the injured side was 64.35±1.38°, which was not statistically different from that of the healthy side. The average range of motion of the subtalar joint was 29.27±1.63°, which was 88.6% of the healthy side, and two patients developed subtalar traumatic arthritis.Conclusion: External fixator-assisted poking reduction and percutaneous screw fixation is a safe and effective minimally invasive surgery for intra-articular calcaneal fractures, which has a lower incidence of postoperative complications and can reduce the impact on subtalar joint mobility, and increase the clinical effect. Trial registration: Retrospective cohort study.