Radiographic predictors of outcome after long fusion to L5 in adult scoliosis

Radiographic factors that correlate with outcome following long posterior fusion to L5 for adult scoliosis were investigated. Measurement of thoracic, lumbar, and fractional lumbosacral curves, L5 obliquity, lumbar and L5-S1 lordosis, coronal balance, sagittal balance, and L5-S1 disc height were performed on preoperative, postoperative, and follow-up 36-in posteroanterior/lateral radiographs. Of 16 patients, 14 were female (88%) and 2 male (12%). Average follow-up was 32 months (8-78 months). Scoliotic curves demonstrated stable corrections; however, lumbar and L5-S1 lordosis decreased and sagittal decompensation worsened. Ten patients (62%) had no evidence of transitional degeneration. Six patients (38%) had radiographic evidence of U-S I degeneration, and three (19%) underwent revision. Patients with good preoperative sagittal balance, preserved lumbar lordosis, good postoperative fractional curve correction, and L5-S1 disc height preservation are most likely to benefit from posterior fusion to L5, avoiding sacral fusion, for adult scoliosis.