Instrumented posterolateral lumbar fusion using coralline hydroxyapatite with or without demineralized bone matrix, as an adjunct to autologous bone

Abstract

Background context: Autogenous posterolateral fusion with and without instrumentation has been reported with good results. However, difficult-to-fuse patients, such as smokers, elderly patients with poor bone quality and/or quantity, or patients with prior posterior surgeries, may have somewhat lower fusion rates. Purpose: To determine the efficacy of coralline hydroxyapatite with or without demineralized bone matrix as a bone graft extender in a human clinical model with long-term follow-up. Study design/setting: A retrospective series of 40 patients undergoing instrumented autogenous posterolateral lumbar fusion augmented with coralline hydroxyapatite with or without demineralized bone matrix. Patient sample: Long-term clinical and radiographic follow-up were examined for 40 patients who underwent an instrumented posterolateral fusion only. Patients undergoing anterior lumbar interbody fusion (ALIF) procedures were not considered part of the sample. Methods: All patients underwent successful transpedicular fixation with autogenous posterolateral lumbar fusion. Fifteen cc of Pro Osteon™ 500 coralline hydroxyapatite (Interpore Cross International, Irvine, CA) was used at each level. An additional 10 cc of Grafton demineralized bone matrix gel (Osteotech, Eatontown, NJ) was used in 70% of these patients. Results: An overall fusion rate of 92.5% was achieved. Pain and function improvement were good but somewhat age dependent and correlated with the number of comorbidities. Patients with Grafton DBM gel had a lower fusion rate of 89.3%. Conclusions: Based on this small retrospective review, coralline hydroxyapatite is an effective bone graft extender in difficult-to-fuse patients as an adjunct to autologous bone for posterolateral fusion of the lumbar spine when combined with rigid instrumentation.