[Short-term effectiveness of TiRobot combined with O-arm navigation system in minimally invasive treatment of hindfoot fracture].

Objective: To investigate the short-term effectiveness of TiRobot combined with O-arm navigation system in the minimally invasive treatment of hindfoot fracture.
Methods: Between March 2019 and March 2021, 25 patients with hindfoot fractures were admitted. There were 14 males and 11 females, with an average age of 51.7 years (range, 19-76 years). The causes of injuries included falling from height in 17 cases and traffic accident in 8 cases. The interval between injury and operation was 1-3 days (mean, 2.1 days). There were 16 cases of calcaneus fracture, 7 cases of talus fracture, and 2 cases of calcaneus and talus fractures. According to Sanders classification criteria, the calcaneus fractures were classified as type Ⅱ in 10 cases and type Ⅲ in 8 cases; according to the Hawkins classification criteria, the talus fractures were classified as type Ⅱ in 4 cases and type Ⅲ in 5 cases. Preoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was 48.1±9.1. During operation, the fractures were fixed with the percutaneous cannulated screws with the assistance of the TiRobot combined with the O-arm navigation system. The operation time, hospital stay, and the occurrence of related complications were recorded. X-ray films were reviewed to evaluate the fracture healing and the occurrence of talus osteonecrosis, and the width, length, height, Böhler's angle, and Gissane's angle of the calcaneus were measured; AOFAS ankle-hindfoot score was used to evaluated the foot function.
Results: The operation time ranged from 47 to 71 minutes (mean, 60.5 minutes). The length of hospital stay ranged from 2 to 5 days (mean, 3.4 days). All incisions healed by first intention. All patients were followed up 12-24 months (mean, 17.3 months). One patient demonstrated hypoesthesia on the lateral side of foot after operation and recovered after symptomatic treatment. All fractures healed confirmed by X-ray films and the healing time ranged from 10 to 16 weeks (mean, 11.8 weeks). No talus osteonecrosis occurred during follow-up. There were significant differences in the width, length, height, Böhler's angle, and Gissane's angle of the calcaneus between pre-operation and at last follow - up ( P <0.05). At last follow-up, AOFAS ankle-hindfoot score was 91.2±5.0, the difference was significant when compared with preoperative score ( t =22.169, P <0.001). The results were excellent in 16 cases and good in 9 cases, with an excellent and good rate of 100%.
Conclusion: TiRobot combined with O-arm navigation system for minimally invasive treatment of hindfoot fractures can obtain the satisfactory short-term effectiveness, with the advantages of less surgical trauma, precise fixation, and fewer complications.