Can a bone marrow-based graft replacement result in similar fusion rates as rib autograft in anterior interbody fusion procedures for adolescent thoracolumbar scoliosis?

Study Design Nonrandomized consecutive case series comparing interbody spine fusion with autograft versus bone marrow-based graft replacement (BGR). Objectives Effectiveness of bone marrow-based graft versus rib autograft in achieving anterior interbody fusion of the thoracolumbar/lumbar spine. Summary of Background Data The use of bone marrow (BM) with graft materials was shown in a prior study to aid with bone regeneration. Limited clinical data are currently available to demonstrate the effectiveness of BM for spinal applications. Engineered matrices of collagen type I coated with hydroxyapatite and combined with BM have been safely used in both spinal and long bone applications. Methods Nineteen consecutive patients from 2003 to 2006 underwent anterior interbody fusion through an anterior approach with dual-rod instrumentation and structural interbody support for thoracolumbar scoliosis. Within 19 patients, there were 42 disc levels treated with graft replacement material combined with BM (BGR+BM) and 25 disc levels with rib autograft. The mean follow-up time was 17 months with a minimum of 6 months. Clinical and radiographic data included Scoliosis Research Society (SRS)-22 questionnaires and pain and fusion assessments of posterior-anterior and lateral radiographs, collected preoperatively and at 6, 12, and 24 months, postoperatively. Results At 6 months, 72% of BGR+BM segments versus 44% of autograft segments were defined as fused. All BGR+BM segments were fused by 12 months, and all autograft segments were fused by 24 months. There was no pseudoarthrosis or instrumentation failure, and interbody fusion rate was 100%. The average correction was 73.5±13.5%. The overall loss of correction from the immediate alignment to postoperative follow-up was less than 4%. There was no loss of sagittal plane alignment or measured kyphosis. No morbidity was observed at the BM aspiration site. Conclusions Anterior spinal fusion using bone marrow-based graft substitutes for thoracolumbar adolescent idiopathic scoliosis demonstrated equivalent results to rib autograft when used with dual-rod instrumentation and structural support. In this patient series, the rate of fusion was faster in the bone marrow-treated segments. These results suggest that for patients as described in this cohort, bone marrow-based graft replacements can thus be used as an alternative, or adjunct, to autograft to achieve interbody fusion in scoliosis surgery.