[Posterior minimally invasive approach for treatment of posterior wall acetabular fractures].

Objective: To investigate the effectiveness of posterior minimally invasive approach in the treatment of posterior wall acetabular fractures. Methods: The clinical data of 17 patients with posterior wall acetabular fractures treated with posterior minimally invasive approach between March 2019 and June 2023 were retrospectively analyzed. There were 14 males and 3 females with an average age of 41 years ranging from 28 to 57 years. The causes of injury were traffic accident in 12 cases and falling from height in 5 cases. There were 3 cases complicated with posterior hip dislocation and 2 cases complicated with sciatic nerve injury. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 11 cases of type A1.1 and 6 cases of type A1.2. The time from injury to operation was 5-8 days, with an average of 6.2 days. The incision length, intraoperative blood loss, and operation time were recorded. The quality of posterior wall fracture reduction were evaluated by Matta criteria, and hip function were evaluated by modified Merle d'Aubign-Postel score criteria at 6 months after operation and last follow-up. Results: The operation was successfully completed in 17 cases. The length of incision ranged from 7 to 9 cm, with an average of 8.3 cm, and all incisions healed by first intention. The intraoperative blood loss ranged from 200 to 350 mL, with an average of 281 mL. The operation time ranged from 45 to 70 minutes, with an average of 57 minutes. Two patients had sciatic nerve injury before operation, and the sciatic nerve function recovered completely at 3 months after operation; the other 15 patients had no symptoms of sciatic nerve injury after operation. All the 17 patients were followed up 14-27 months, with an average of 19.5 months. At 1 week after operation, according to the Matta criteria, anatomical reduction was achieved in 12 cases and satisfactory reduction in 5 cases, with a satisfaction rate of 100%. According to the modified Merle d'Aubign-Postel scoring system, the hip function score was 13-18 (mean, 16.1) at 6 months after operation. Among them, 5 cases were excellent, 9 were good, and 3 were fair, with an excellent and good rate of 82.4%. At last follow-up, the hip function score was 7-18 (mean, 13.7), of which 3 cases were excellent, 9 were good, 3 were fair, and 2 were poor, with an excellent and good rate of 70.6%. During the follow-up, there was no infection, failure of internal fixation, and femoral head necrosis, and heterotopic ossification occurred in 2 cases. Conclusion: The posterior minimally invasive approach has the advantages of less trauma, shorter operation time, less blood loss, without cutting off the external rotator muscle. Exposure through the gluteus medius-piriformis space and piriformis-supercilium space can provide sufficient safe exposure for the posterior wall acetabulum fracture, which is a reliable alternative approach for the posterior acetabular fracture.