(P 32) CURRENT INDICATIONS OF OPEN SURGERY IN PRIMARY APPENDICULAR/ PELVIC ANEURYSMAL BONE CYSTS

Objective: Over last 2 decades, treatment of Aneurysmal bone cysts (ABC’s) have evolved from open surgical procedures to various percutaneous treatments. Sclerotherapy with polidocanol being the most commonly used with a reliable success.
We ask (1) How successful is sclerotherapy alone in ABC (2) When do we need open surgery?

Methods: We analyzed 149 patients with primary ABC of the extremity treated between January 2010 and October 2022. 109 (73%)had upfront percutaneous polidocanol sclerotherapy , 20 (13.5%) had upfront extended curettage, 20 (13.5%) were treated with other modalities (angio-embolisation, denosumab, combined treatments etc.).

Results: Indications for upfront surgery (20) were expected sclerosant leak in 8 patients, pathological fracture, expected poor cosmesis and very large uncontained lesions in 2 patients each while diagnostic dilemma in 6 cases. A total of 22 procedures were performed in these 20 patients, 15 intralesional surgeries and 7 resections with appropriate reconstructions.
Out of 109 patients with sclerotherapy, 95 (87%) healed while 14 (13%) required open surgery. Mean number of injections in this subgroup was 2.4 (1-6). The reasons for open surgical procedure was no/ partial response in 7 patients (Mean 2.8 injection), progression on sclerotherapy in 6 patients (Mean 1.8 injections) while 1 surgery was done due to partial response and fracture. Seven underwent curettage, 2 required amputation, 4 needed excisions while 1 case was treated with ORIF with bone grafting.

There were no recurrences in all surgically treated patients at a mean follow up of 3.5 years.

Conclusion: Percutaneous sclerotherapy alone is successful in 87% of primary ABCs in this series. We recommend extended curettage surgery, in large uncontained defects, pathologic fracture or risk of fracture in high stress high risk zones or cases with partial healing or in cases with rapid progression.