Spinal fusion is one of the most common clinical indications for bone grafting. However, synthetic bone substitutes are needed to ameliorate limited availability, donor site morbidity, and potential disease transmission concerns associated with autograft and allograft. One new synthetic bone substitute, Vitoss (Orthovita, Malvern, Pa), is an ultraporous formulation of beta-tricalcium phosphate (beta-TCP). This study examines 50 patients who received ultraporous beta-TCP bone void filler as an adjunct to autogenous bone graft while undergoing spinal fusion procedures. All patients underwent decompressive laminectomy with bilateral posterolateral intertransverse fusion (PLITF) using bone graft mixed with ultraporous beta-TCP, with and without instrumentation. Some patients also underwent posterior lumbar interbody fusion (PLIF) using cages and bone graft. Thirty-two patients were studied for at least 5-7 months postoperatively. Of these patients, 100% demonstrated good consolidation on follow-up radiographs. The use of iliac crest bone graft (ICBG) was avoided entirely in 7 (14%) of the 50 patients, and 30% less ICBG volume was required on average in others. Only 3 patients (7%) had donor site-associated pain. Controlled studies are being conducted to support the clinical impression that ultraporous beta-TCP used as a bone void filler in spinal arthrodesis facilitates bone healing at both the spinal and donor operative sites, and contributes to less overall morbidity.