Minimally invasive treatment of calcaneal fractures based on 3D fluoroscopic robot-assisted percutaneous reduction and screw fixation combined with a novel circular distractor

Objectives: To introduce a surgical technique and evaluate the clinical outcome of minimally invasive treatment of calcaneal fractures based on 3D fluoroscopic robot-assisted percutaneous reduction and screw fixation combined with a novel circular distractor. Methods: Design : Retrospective case series. Setting: Single Level-1 trauma center. Patients: Adult patients with calcaneal fractures (OTA/AO 82C, Sanders type II, III) who were treated with 3D fluoroscopic robot-assisted percutaneous reduction and screw fixation combined with a novel circular distractor from January 2022 to June 2024 were included. Outcome measures and comparisons: Demographic characteristics, operative information, radiological and functional outcomes, and complications. Results: Forty-seven patients (43 men and 4 women, 52 fractures) with a mean age of 46.5±12.2 years (range: 24–73), a mean weight of 73.4±13.0 kg (range: 55–106), and a mean height of 170.1±6.4 cm (range: 150–180) were followed for an average duration of 20.4 months (range: 9–36 months). According to the Sanders classification, there were 39 type II and 13 type III fractures. Based on the Essex–Lopresti classification, 25 fractures were tongue-type and 27 were joint depression-type. The average time from injury to surgery was 8.7±4.2 days (range: 2–18), and the mean operative duration was 86.8±33.9 minutes (range: 45–180).Postoperative radiographic parameter assessment revealed significant restoration of the calcaneal anatomy, with a marked reduction in width (from 47.8±4.6 mm to 43.4±4.2 mm, P < 0.001) and significant improvements in height (from 39.3±4.8 mm to 46.2±4.0 mm, P < 0.001) and length (from 79.2±5.9 mm to 81.6±5.1 mm, P < 0.001). Furthermore, both Böhler’s angle (from 7.4±13.5° to 25.4±9.2°, P < 0.001) and Gissane’s angle (from 119.3±13.4° to 113.4±10.1°, P < 0.001) were significantly corrected. The vertical articular step significantly decreased from 4.3±0.8 mm before the operation to 0.9±0.5 mm (P < 0.001). There were no wound complications. At the final follow-up, the mean Maryland Foot Scale (MFS), American Orthopedic Foot and Ankle Society (AOFAS) ankle–hindfoot score, and visual analogue scale (VAS) score were 93.5±6.4, 91.3±7.6, and 1.0±1.0, respectively. No patients required secondary surgery, except for five patients for whom the internal fixation was removed. Conclusions: This study demonstrated favorable clinical outcomes for the minimally invasive treatment of calcaneal fractures using 3D fluoroscopic robot-assisted percutaneous reduction and screw fixation in combination with a novel circular distractor. This surgical protocol is suggested to be both safe and reliable on the basis of this findings. Level of evidence: Therapeutic Level IV.