Iliac bone cysts adjacent to the sacroiliac joint: an unusual cause of sacroiliac pain

Objective: The aim of this study was to describe cystic bone lesions involving the sacroiliac region of the iliac bone as a rare cause of sacroiliac joint-related pain. Methods: The study included 9 patients with benign cystic bone lesion in Zone 1 according to Enneking and Dunham with a minimum of 2 years follow-up. Detailed radiological examination was performed using magnetic resonance imaging or computed tomography. Extended curettage, adjuvant treatment with phenol and thermal cauterization and bone grafting with auto/allografts were performed. Patients were analyzed for age of onset, side of involvement, clinical and radiological findings, tumor stage, complications and clinical/radiological findings at the final follow-up. Results: Female to male ratio was 4 to 5. Average age at the time of diagnosis was 40.3 (range: 27 to 54) years. Average diameter of the lesion was 6.6 (range: 4 to 11) cm. Superficial infection was detected in one patient and hypoesthesia around the site of incision in two. Clinical improvement in pain and limp was reported in all patients. No radiological recurrence was detected after an average follow-up time of 30.7 (range: 21 to 40) months. Conclusion: Benign tumor-like cystic lesions should be kept in mind in the differential diagnosis of sacroiliac joint-related pain. Such lesions can be safely and effectively managed with intralesional curettage, local adjuvant methods and bone grafting.