Healos and bone marrow aspirate used for lumbar spine fusion - A case controlled study comparing healos with autograft

Study Design. A prospective case controlled study to compare the clinical and radiographic performance of Healos soaked in bone marrow aspirate (BMA) to iliac crest autograft when used in lumbar spinal fusion. Objective. To evaluate the null hypothesis: Healos used with BMA is not an effective alternative to iliac crest autograft in lumbar spine fusions. Summary of Background Data. Healos (a Type 1 collagen/hydroxyapatite matrix) is osteoconductive and when soaked for at least 20 minutes in BMA becomes osteoinductive. It is nontoxic and straightforward to use, avoiding the morbidity of autograft harvest. Animal studies and early clinical series in humans have suggested that Healos and BMA are an effective substitute for autograft in certain circumstances. Methods. From July 2000, Healos and BMA were used as the graft material, instead of autograft harvested from the iliac crest, in all patients undergoing lumbar spinal fusion. Clinical outcome measures used were the Low Back Outcome Score (LBOS), a Patient Satisfaction Score, and the Prolo Economic Score (after Schnee). Standing anteroposterior and lateral radiographs were taken at 12- and 24-month follow-up visits. The first 50 cases in this consecutive series were age, sex, and operative intervention matched to historical controls who underwent surgery between 1997 and 2000 and in whom autograft from the iliac crest had been used as the graft material. Surgical outcome data in these patients had also been gathered prospectively. An independent radiologist, blinded to the graft material, using standard plain radiograph criteria for fusion, examined all the radiographs. An independent surgeon assessed clinical outcomes. Results. For posterolateral lumbar fusions, there were equivalent radiologic fusion rates for the 2 groups with no significant difference in the subjective and objective clinical outcomes. The radiologic fusions rate was significantly lower when Healos had been used for lumbar interbody fusions. Clinical outcomes for both groups were similar. There were no lasting complications associated with Healos use compared with a 14% persisting donor site complication rate in the autograft patients. Conclusion. The null hypothesis is only partially correct. Healos and BMA are not inferior to autologous iliac crest bone as a graft material in posterolateral lumbar spine fusions but are radiographically ineffective in lumbar interbody fusions.