Packing with high-porosity hydroxyapatite cubes alone for the treatment of simple bone cyst

In 23 patients, simple bone cysts were treated by curettage followed by packing the cavity with cubes of high-porosity hydroxyapatite (HA). In 22 patients, HA was packed exclusively without autogeneic bone graft. Except in one patient who sustained pathologic fracture at the femoral diaphysis, HA was packed with a fibula strut graft. Each case had an uneventful postoperative course and was followed, on average, two years. Complete healing without cyst recurrence occurred in 18 cases (78%). In three cases--all rapidly growing children--a new cyst appeared between the epiphyseal plate and the HA packing, but the original cysts did not recur. In two multiloculated cysts, the cavities were not filled fully and healing was incomplete, yet there was no cyst recurrence. In the entire group, new bone surrounding HA was roentgenographically evident within an average of 2.3 months. Thus, the result of packing high-porosity HA for simple bone cysts compares favorably with the cure rates reported either with autogeneic bone graft, or topical steroid injection.