Outcomes of Open Arthrotomy and Arthroscopic Surgery for Primary Synovial Chondromatosis of the Hip: A Comparative Study With Propensity Score Matching.

Background: Despite the widespread use of arthroscopic surgery for hip synovial chondromatosis, its postoperative outcomes remain uncertain. A head-to-head comparison between open arthrotomy and arthroscopic surgery is lacking.

Purpose: To compare the treatment outcomes of open arthrotomy, particularly with surgical dislocation, and arthroscopic surgery for hip synovial chondromatosis.

Study design: Cohort study; Level of evidence, 3.

Methods: All patients who were surgically treated for symptomatic synovial chondromatosis in a tertiary university referral hospital between April 1996 and February 2023 were investigated via 1:1 propensity score matching to compare open arthrotomy and arthroscopic surgery. The primary outcome was chondromatosis recurrence. Secondary outcomes were patient-reported outcome scores, reoperations, and complications.

Results: A total of 73 patients were enrolled, and after matching, 28 patients in each group were investigated. The mean age and mean follow-up period were 40.5 ± 13.7 years and 4.0 ± 3.1 years, respectively. Clinical and radiological recurrence rates did not differ between groups (clinical recurrence: 7.1% for open arthrotomy vs 25.0% for arthroscopic surgery [P = .143]; radiological recurrence: 14.3% for open arthrotomy vs 32.1% for arthroscopic surgery [P = .205]). However, all patient-reported outcomes at final follow-up were in favor of open arthrotomy compared with arthroscopic surgery (visual analog scale for pain: 1.6 for open arthrotomy vs 3.1 for arthroscopic surgery [P = .002]; quality of life scale: 80.4 for open arthrotomy vs 65.4 for arthroscopic surgery [P < .001]; and modified Harris Hip Score: 84.4 for open arthrotomy vs 75.9 for arthroscopic surgery [P = .001]). The symptom dissatisfaction rate at final follow-up was significantly higher with arthroscopic surgery than with open arthrotomy (35.7% vs 7.1%, respectively; P = .020). There was no difference in reoperation and complication rates between the 2 groups.

Conclusion: For treating primary synovial chondromatosis, particularly when it is distributed across both the central and peripheral zones, arthroscopic surgery should be chosen with caution, and open arthrotomy with surgical dislocation should be actively considered.