Which is the optimal minimally invasive treatment for osteoid osteoma of the hip? A systematic review and proportional meta-analysis.

Abstract Background Osteoid osteomata comprise approximately 10% of benign bone tumours, with 20% of them being located in the proximal femur and 1–3% in the pelvis. In this meta-analysis, we sought to investigate positive and negative outcomes relating to minimally invasive surgery (MIS), which has superseded open resection and conservative measures over the last decades. Methods We searched the PubMed, CENTRAL and grey literature for completed studies published until 10 August 2020. Articles with a minimum of ten patients diagnosed with osteoid osteomata of the proximal femur and/or acetabulum were included. Primary outcomes were success rates, complications and recurrences following treatment. Delays in diagnosis were also recorded. We conducted random effects meta-analysis of success rates for MIS modalities using MedCalc statistical software. Quality was assessed with a modified Delphi checklist. Results Sixteen case-series were identified. Success rates for computed-tomography (CT)-guided radiofrequency ablation (RFA), CT-guided percutaneous resection drilling and arthroscopic resection were 98.2% (95% CI 95.8–99.5), p = 0.47; 91.5% (95% CI 81.1–97.9), p = 0.06; and 98% (95% CI 89.3–99.7), p = 0.95, respectively. Both RFA and percutaneous drilling resection were associated with two iatrogenic femoral fractures. Arthroscopic removal was not associated with any complications. Definitive diagnosis was established at least six months after symptom onset in up to 43% of patients. Conclusions RFA could be the most effective treatment options for patients suffering from osteoid osteomata of the hip. Arthroscopy could be potentially as effective as RFA as long as further large-scale studies confirm its efficacy and safety. Reported complications stemming from these modalities were sparse in nature. In order to avoid inordinate diagnostic delays, a high index of suspicion and low threshold for CT scan investigation is required.