OBJECTIVETo analyze the radiological change of intervertebral angles after the short-segment fusion of degenerative lumbar scoliosis.

METHODSFrom January 2001 to May 2007, 28 patients (mean age 62 years old) with degenerative lumbar scoliosis, including 6 male and 22 female, were reviewed retrospectively. The average vertebra number in the lumbar curve were 4.8, ranging from 3 to 6. All the patients underwent posterior decompressive laminotomy, pedicle screw fixation, and posterolateral fusion. The fusion levels were within the curve in all the cases (mean 3.3 vertebrae), without exceeding the end vertebrae. All the patients took standing lumbar antero-posterior and sagittal radiological images pre and post-surgery and upon follow up. The coronal scoliosis Cobb angle, anterior and sagittal intervertebral angles of upper adjacent segment of proximal fused vertebra were measured. The following aspects were also evaluated such as bone graft fusion and complications.

RESULTSFollow up period of 25-97 months, average 50 months; post-operative scoliosis Cobb angle average correction rate was 33.7%, final follow up average correction loss was 3.7 degrees , pre-operative and final follow up results compared with post-operative indicated significant difference (P < 0.05); final follow-up antero-posterior proximal upper fusion segment intervertebral angle compared with pre-operative and postoperative presenting significant difference (P < 0.05). Upon final follow up, all cases did not present pseudo-arthrosis or internal instrumentation related complications.

CONCLUSIONFor degenerative lumbar scoliosis, short-segment fusion can produce limited correction on antero-posterior proximal upper fusion segment intervertebral angle and cannot stop its aggravation.