INTRODUCTION: When the physicians plan a surgery for the degenerative lumbar spondylolisthesis (DLS) with low back pain (LBP), it should be a considerable option whether they do decompression alone or add fusions. The sagittal balance of the lumbar spine is thought to be an important factor as well as the slippage itself. The purposes of this study were: 1) to examine whether LBP in the DLS was improved by decompression surgery and 2) to determine the relationship between LBP and sagittal balance in the DLS.
METHODS: From 286 DLS patients, 62 cases were subjected to the study by the following criteria. The inclusion criteria were: 1) more than 3 mm of vertebral body slippage, 2) treated by decompression (without fusion). The exclusion criteria were: 1) lumbar scoliosis more than 20°, 2) the past history of lumbar surgery, compression fracture or osteoarthritis of the hip/knee joint. The surgical outcome was evaluated using subjective symptom items of JOA score (9 points of perfect scores) and a visual analog pain scale. The lumbar axis S1 distance (LASD) and lumbar lordosis (L1‐L5) were measured as an index of the sagittal balance. Relations among surgical outcomes and radiographic indexes were non‐parametrically analyzed (statistical significant level p< 0.05).
RESULTS: Recovery rate based on JOA score was 67.2±23.8%. LBP was improved in 38 of 56 patients (63.3%) by decompression alone. The LASD was significantly decreased after surgery (18.5mm→13.3mm) and showed a negative correlation with the lumbar lordosis. Improving of LBP was significantly correlated with the decrease of the LASD. Leg pain or numbness was not correlated with any radiographic indexes.
DISCUSSION: Almost 60% of the DLS patients improved LBP by decompression surgery associated with sagittal balance. Because this study has a limitation due to its retrospective design, a randomized controlled trial should be needed in the future.