OBJECTIVETo evaluate the role that post-operative difference value of pelvic incidence and lumbar lordosis (PI-LL) played on loss of correction, implant failure and health-related quality of life during follow-up in degenerative scoliosis patients.

METHODSRetrospective review of 62 patients (average age (57 ± 10) years, 11 male and 51 female patients) with degenerative scoliosis who underwent one stage posterior surgical instrumentation in the affiliated Drum Tower Hospital of Nanjing University Medical School from January 2005 to December 2011. The mean follow-up duration was 4.2 years. Long-cassette standing upright sagittal radiographs were obtained before and after operation and at the last follow-up. At the last follow-up, visual analogue scale and Oswestry disability index were collected. Based on post-operative PI-LL, patients were divided into two groups: group A (-9° < post-operative PI-LL<9°) and group B (post-operative PI-LL < -9°or post-operative PI-LL>9°). Independent t test and χ(2) test were performed for statistical analysis. For all statistical analysis, the level of significance was set at P < 0.05.

RESULTSNo difference was observed in terms of loss of correction between two groups during follow-up. More implant failure were observed in group B (15.63% vs. 6.7%, χ(2) = 21.85, P = 0.012). In addition, patients with better PI-LL matching came with better visual analogue scale (3.9 ± 2.4 vs. 5.2 ± 3.3, F = 0.089, P = 0.024).

CONCLUSIONWorse quality of life and increased risk for implant failure during follow-up may be related to mismatched PI-LL.