Extension of spine fusion to the sacrum following long fusions for deformity correction

STUDY DESIGN.: Retrospective review of prospective database. OBJECTIVE.: To investigate the long-term results after extension of previous long spine fusions to the sacrum. SUMMARY OF BACKGROUND DATA.: Long spine fusions not involving the sacrum may be complicated by distal degeneration and require subsequent extension to the sacrum. The clinical and radiographical outcomes after such revision remain unknown. METHODS.: Patients who had extension of a long fusion (≤5 levels with a thoracic level at the cranial end) to the sacrum between 2002 and 2007 at a single institution were analyzed. Oswestry Disability Index and Scoliosis Research Society scores and/or radiographical parameters were assessed at baseline, 6 weeks and 1 year, 2, 3, and/or 5 years postoperatively (PO) and complications were recorded. RESULTS.: There were 74 patients with an average age of 49 years (range, 19-76 yr) and average clinical follow-up of 4.5 years (range, 3 mo-10 yr, 82% >2 yr PO). All had degeneration distal to prior fusions and 72% (n = 53) had fixed sagittal imbalance. Sagittal alignment improved at all PO time points from baseline (mean, 78 mm), but worsened between 1 year (mean, 21 mm) and 5 years PO (mean, 44 mm, P = 0.01). Major surgical complications occurred in 30% (n = 22) and there were 17 major reoperations in 15 patients (20%). Significant improvements (P < 0.05) in Oswestry Disability Index and all Scoliosis Research Society domain scores were found at each PO time point with no deterioration from 1 to 5 years PO. Mean outcome scores at 5 years PO were similar in groups with major surgical complications versus without and with major reoperation versus without. CONCLUSION.: Extension of long fusions to the sacrum resulted in significant and sustained improvements in Oswestry Disability Index and Scoliosis Research Society scores and alignment during 5 years PO compared with baseline. Major surgical complications occurred in 30% and reoperations were performed in 20%, but outcome scores after treatment were similar to those without complications or reoperations.