Metatarsal Aneurysmal Bone Cysts Treated With En Bloc Resection and Reconstruction With Fibular Allograft.

Abstract

Background: Treatment of Primary metatarsal aneurysmal bone cyst (ABC) with curettage and bone grafting unfortunately has a high recurrence rate, particularly in short tubular bones. This study presents a 16-year experience treating ABCs in the bones of the foot at an orthopaedic oncology referral center. Treatment involved en bloc resection and reconstruction of the defect with fibular allograft in all cases. Retrospectively collected data were used to document the outcomes.

Methods: This retrospective review includes patients with primary metatarsal ABC treated en bloc resection at a single center between 2004 and 2020. Information on the diagnosis, treatment, complications, and outcomes was collected from our database for all eligible patients. Radiologic healing was used as our primary outcome measure. The patient's function was assessed using the Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) score.

Results: The study included 19 subjects (11 women, 8 men) with a mean age of 18 years (SD 11-35). The average resected length was 4.24 cm (3-6 cm). The mean follow-up time was 79.26 months (28-160 months). The mean TESS score and MSTS were 94.52 and 28.42, respectively. The average healing time was 10.2 weeks. No patient had local recurrence. Arthrodesis was performed in 3 patients because of joint involvement. Repeat surgery was performed for 2 patients, debridement for one because of infection and bone graft for another because of nonunion. One patient had experienced an allograft fracture.

Conclusion: Based on the Enneking classification, our experience has shown that a reasonable surgical approach for primary active and invasive metatarsal ABC is en bloc resection and reconstruction with fibula allograft. This method has a low risk of recurrence and does not result in significant functional impairment.