Midterm Clinical, Radiological, and Functional Results of Arthroscopic Excision of Osteoid Osteoma of the Hip Joint: a Case Series.

Purpose: We aimed to evaluate the midterm functional and clinical outcomes of the patients who underwent arthroscopic excision of hip osteoid osteoma (OO). Methods: We reviewed records of patients diagnosed with intra-articular hip OO, treated with hip arthroscopic excision procedure, and a minimum of 1-year postoperative between 2011 and 2020. Clinical outcomes were assessed range of motion (ROM) pre and postoperatively, and functional outcomes were evaluated with a modified Harris hip score (modified HHS) and Visual analog scale test. All patients were assessed by hip radiography, and three radiological measurements, including lateral center-edge angle (LCEA), alpha angle, and Tönnis angle, were measured. These parameters were compared with unaffected hips. Results: Fifteen (5 female and 10 male) patients were included in the study, with a mean age of 32.6 ± 12.7 (range 12-53). The average postoperative follow-up period was 59.1 ± 28 (range 13-106) months. The functional and clinical scores were significantly improved at the final visit compared to the preoperative values. No differences were found between the operated and unaffected sides with respect to the radiological parameters. The preoperative alpha was significantly higher on the operated side than on the unaffected side ( Conclusion: In this study, within an average of 5 years after surgery, hip arthroscopy provided successful clinical outcomes in the treatment of OO of the hip joint without recurrence. The modified HHS, VAS, and HOS values improved significantly at the final follow-up; 14 of 15 patients had satisfactory outcomes after hip arthroscopy for hip OO. Level of Evidence: Prognostic Level IV study.