Extension of fusions to the pelvis in idiopathic scoliosis

Study Design, Retrospective study of patients after extension of previous s coliosis fusions to the pelvis. Objective. To determine whether modern instrumentation and surgical techniq ues provide for increased fusion rates with fewer complications. Summary of Background Data. Traditionally, long fusions to the pelvis in ad ults with idiopathic scoliosis have resulted in high complication rates, in cluding pseudarthrosis. Methods. The hospital and clinic charts of 41 patients (40 female, 1 male) were reviewed 41 months (range: 24-116) after surgery for extension to the pelvis of previous scoliosis fusions. Thirty-nine of 41 had a combined ante roposterior fusion extension; two had posterior extension only. In 37 of 41 patients, Cotrel-Dubousset (CD) instrumentation was used; in two, Isola (A cromed Corp., Cleveland, OH), in one, TSRH; (Sofamor-Danek, Memphis, TN), a nd in one, Synergy (Cross Medical Products, Columbus, OH). Parameters analy zed were fusion rate, sagittal and coronal balance, lumbar lordosis, length of fusion extension, and distal fixation method. Results. Complications were seen in 30 of 41 patients. The pseudarthrosis r ate was 37% (15/41) and was significantly related to the method of distal p osterior fixation. With sacral fixation only, the rate was 53% (8/15), with iliac fixation only 42% (3/7), and with both iliac and sacral fixation 21% (4/19; P < 0.05). This was not correlated with fusion rate, and the length of fusion extension did not affect the pseudarthrosis rate or sagittal bal ance. Conclusion. When fixed to the ilium and sacrum, modern instrumentation appe ars capable of maintaining sagittal balance with lower rates of pseudarthro sis when previous scoliosis fusions are extended to the pelvis. The complic ation rate remains significant.