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

Background:   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.     Methods:   From November ۲۰۰۸ to November ۲۰۱۱, ۲۳۶ patients participated in this study. Peek cages were packed with autologous bone grafts taken from the iliac crest in ۱۱۲ patients and hydroxyapatite (HA) granules in ۱۲۴ patients.   Patients were followed for ۱۲ 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.     Results:   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 ۱۲-month follow-up assessment. No difference (     P > ۰.۰۵)   was found regarding improvement in neurological deficit as well as radicular pain and recovery rate between the two groups. Conclusions:   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.    

Keywords:

Autograft , Cage , Hydroxyapatite granules , Interbody fusion , Settling ratio