Efficacy of Outside-In Hip Arthroscopy without Traction in the Treatment of Hip Synovial Osteochondromatosis.

Arthroscopic treatments of hip synovial osteochondromatosis are mostly performed under traction, resulting in neurovascular injury or iatrogenic damage to the labrum or cartilage. This study aimed to assess the effectiveness of outside-in hip arthroscopy without traction in treating hip synovial osteochondromatosis. This retrospective study was conducted on a series of patients with hip synovial osteochondromatosis treated using outside-in hip arthroscopy without traction in our hospital between 2018 and 2020. Plain radiography and magnetic resonance imaging (MRI) scans were obtained. The Harris hip score (HHS), hip range of motion (ROM), and visual analog scale (VAS) scores were analyzed. The preoperative scores and last follow-up scores were compared with a paired-sample t test. The complications and recurrence postsurgery were recorded. This study included five patients (three male and two female) with an average age of 41 years (range 28-54 years). The mean follow-up time was 25.2 months (range 18-36 months). All patients experienced groin pain relief and improved ROM. The mean VAS score was significantly lower postoperatively (0.4 ± 0.5) than preoperatively (3.2 ± 0.8) (p < 0.001). The mean HHS improved from 58.6 ± 12.7 (range 43-73) to 89.8 ± 5.26 (range 81-95) (p < 0.001). No major complications, including infection, perineal numbness and swelling, neurotrosis, thromboembolism, or severe persistent pain, were reported. Synovial osteochondromatosis recurred in one patient after 2 years of follow-up without any obvious symptoms such as hip pain or joint locking. Therefore, no further treatment was necessary. This study showed that outside-in hip arthroscopy without traction might be a viable option for treating hip synovial osteochondromatosis, effectively and safely relieving symptoms with minimal complications, especially in patients without lesions in the central compartment.