Comparison of outcomes and safety of using hydroxyapatite granules as a substitute for autograft in cervical cages for anterior cervical discectomy and interbody fusion

After cervical discectomy, autogenetic bone is packed into the cage to increase the rate of union between adjacent vertebral bodies, but donor site–related complications can still occur. In this study we evaluate the use of hydroxyapatite granules as a substitute for autograft for interbody fusion. From November 2008 to November 2011, 236 patients participated in this study. Peek cages were packed with autologous bone grafts taken from the iliac crest in 112 patients and hydroxyapatite (HA) granules in 124 patients. Patients were followed for 12 months. The patients’ neurological signs, results, and complications were fully recorded throughout the procedure. Radiological imaging was done to assess the fusion rate and settling ratio. Formation of bony bridges at the third month was higher in the autograft group versus the granule group. However, there was no difference between both groups at the 12-month follow-up assessment. No difference (P > 0.05) was found regarding improvement in neurological deficit as well as radicular pain and recovery rate between the two groups. Interbody fusion cage containing HA granules proved to be an effective treatment for cervical spondylotic radiculopathy and/or myelopathy. Clinical and neurological outcome, radiographic measurement and fusion rate in cage containing HA are similar and competitive with autograft packed cages.