Free non-vascularized fibular graft reconstruction after resection of metacarpal unicameral bone cyst: A case report

Unicameral bone cyst (UBC) or simple bone cyst (SBC) is a benign cystic lesion commonly found in the humerus and femur that is mainly encountered during childhood. The currently available treatments for UBC of the hand commonly involve curettage, bone grafting, partial resection with or without grafting, multiple drilling, fracture immobilization and observation alone, and steroid injection. We herein report a case treated with total resection of the cyst and non-vascularized fibular graft in a 9-year-old right-handed female patient. The patient presented with a chief complaint of a large, fast growing lump over the first metacarpal of the left hand. Flexion of the first metacarpophalangeal joint was limited. After the diagnosis was established with plain radiographs followed by biopsy, the cyst was completely removed by resecting the shaft of the metacarpal bone with preservation of the epiphyseal plate. A bone graft was obtained from the fibula and inserted in the gap, distally attached to the epiphyseal plate of the metacarpal and fixed with a Kirshner wire proximally. Radiographs revealed solid union of the bone graft to the epiphyseal plate at the head after 7 weeks, with improving function of the thumb. SBC or UBC of the metacarpal bone is very rare. A more aggressive method, such as in the case presented herein, may be necessary to treat this condition.