Surgical treatment scenario for osteoblastoma of the pelvis: Long-term follow-up results

Background: The aim of this study was to evaluate the results of different treatments for pelvic Osteoblastoma (OB). Methods: We retrospectively evaluated 34 patients affected by primary pelvic OB from 3 oncologic referral centers. Patients with a minimum follow-up of 24 months were included. Local recurrence (LR) rate and complications were recorded. Results: The primary treatment was radio-frequency ablation (RFA) in 4 patients (11.8%), curettage (ILC) in 21 (61.7%) and resection (EBR) in 9 (26.5%). Mean follow-up was 8.9 years (SD ± 6.6). Local recurrence free survival (LRFS) rate after primary surgery was 79.4% at 3 and 5 years. In details, LRFS rate at 3 and 5 years was 50.0% in RFA, 81.0% in ILC and 88.9% in EBR. Post-operative complications occurred in 6/34 patients (17.7%), in particular after EBR. Conclusions: RFA is the least invasive technique to treat OB but with high LR rate. Thus, it should be reserved to very small lesions. ILC is a suitable treatment for stage II OB. For stage III OB, EBR is the treatment of choice, despite an increased risk of complications. For selected stage III OB (relatively small, periacetabular area) ILC might be considered.