Lateral lumbar interbody fusion using a cellular allogeneic bone matrix in the treatment of symptomatic degenerative lumbar disc disease and lumbar spinal instability.

Abstract

Cellular allogeneic bone grafts are used as a biologic adjuvant in lumbar spinal fusions. The clinical use of a minimally invasive extreme lateral approach to the lumbar spine has been widely adopted; however, there are few clinical studies that have documented the clinical and radiographic outcomes associated with the use of cellular allografts as an adjunct to fusion in this advanced surgical approach. A consecutive series of 67 patients (34 males and 33 females) with a mean age of 66.8 years (26-85 years) who underwent single- or multilevel lateral lumbar interbody fusion (LLIF) with supplemental posterior segmental spinal fixation using a cellular allogeneic bone matrix as the only bone graft material was retrospectively reviewed by a single surgeon. Patients' preoperative and 3- and 12-month postoperative data were studied. All patients were followed for a minimum of 12 months. Standardized clinical outcome measures-36-Item Short Form Surgery (SF-36), Oswestry Disability Index (ODI), and visual analog scale (VAS) back and leg pain scores-were used to evaluate the clinical outcomes. An average of 2.25 levels was treated per patient (151 total levels). Fusion status was assessed by dynamic radiographs and computed tomography (CT) scans. The statistical method used to identify the significance of the observed changes in clinical outcomes was the paired 2-sided t-tests. Significance was ascribed to P values <0.05. Fusion was achieved at 142 levels (142/151; 94%). Eight levels (8/151; 5.3%) showed partial fusions and one patient (single level) had no fusion. In the group of patients with fusions, the mean back and leg pain scores showed improvement from preoperative scores at both 3 and 12 months (P<0.001). Functional outcomes showed similar clinical success in both in SF-36 and ODI scores. The use of a cellular allogeneic bone matrix provided osteoconductive and osteoinductive components for successful spine fusions and was associated with statistically significant improvement in SF-36, VAS, and ODI scores.