Lumbar posterolateral fusion with biphasic calcium phosphate ceramic

The authors conducted a retrospective observational study of patients who n eeded lumbar posterolateral fusion (PLF) using a biphasic calcium phosphate ceramic implant as a substitute for bone graft. The findings of clinical, radiographic, and histologic examinations were reviewed. Thirty-two patient s underwent single-level PLF with instrumentation. In all cases, to decreas e the occurrence of donor-site complications and morbidity, locally harvest ed morselized bone from the decompressive site was mixed with hydroxyapatit e and beta-tricalcium phosphate (HAP-TCP) granules and sticks and used for fusion at the posterolateral aspect of the lumbar spine. The histologic fin dings of three biopsy specimens obtained during second operations for metal lic implant removal were reviewed. The minimum follow-up period was 26 mont hs. There was no evidence of instrument loosening or breakage. However, bon e-graft incorporation was difficult to evaluate radiographically, because i mage quality was inferior to that with conventional autogenous iliac bone g raft. Partial graft bone resorption was revealed on radiographs in 75% of c ases. The results showed clinical improvement in all but one case. Solid fu sion was observed during the second operation in all three cases. Histologi c analysis showed excellent bone incorporation around the HAP-TCP granules. These findings suggest that, although the bulk of the fusion mass with HAP -TCP was smaller than that with autogenous bone, this technique combined wi th rigid instrumentation is a safe and effective procedure.