[Repairing bone defect with nano-hydroxyapatite and polyamide 66 composite after giant cell tumor operations]

To evaluate the clinical effectiveness and safety of using granular type nano-hydroxyapatite and polyamide 66 (n-HA/PA66) composite in repairing bone defects caused by giant cell tumors.

48 patients with giant cell tumors, who underwent lesion curettage, inactivation and cavities fill-in with granular type n-HA/PA66 from December 2007 to May 2011, were followed up. Routine blood tests, liver and kidney functions, serum calcium and phosphorus, and immunologic parameters were examined before and after the surgeries. Radiological examinations were carried out 1 week and 1, 3, 6 and 12 months post operations to monitor the bone repairing process. The n-HA/ PA66 in bone issues was detected with hematoxylin-eosin staining.

45 patients completed the follow-up. No significant abnormalities in routine blood tests, serum calcium and phosphorus, and immunologic parameters were found pre- and post-operations. Nor abnormal liver and kidney functional lesions were identified. The radiological examination showed gradual increase in the density of the focal zone after bone implanting operations. The bone density of the implanted areas got close to normal 1 year after operations. The histological examination found that osteoblasts grew into the hole of n-HA/PA66; calcium was deposited on the materials; and large amount of osteocytes inlaid into the composite. The composite was integrated into new bone and surrounding tissues.

n-HA/PA66 has good biocompatibility and biological safety. It also has good osteoconduction and osteogenesis activity. The n-HA/PA66 composite is one perfect bone repair material.