LUMBAR LAMINECTOMY ALONE OR WITH INSTRUMENTED OF NONINSTRUMENTED ARTHRODESIS IN DEGENERATIVE LUMBAR SPINAL STENOSIS - PATIENT SELECTION, COSTS, AND SURGICAL OUTCOMES

Design. A prospective, multicenter observational study. Objectives. 1) identify correlates of the decision to perform arthrodesis in patient s undergoing laminectomy for lumbar spinal stenosis. 2) Compare sympto ms, walking capacity, and satisfaction 6 and 24 months after laminecto my alone end laminectomy with noninstrumented and with instrumented ar throdesis. Background Data. Few prospective studies have compared outc omes of laminectomy alone or laminectomy with noninstrumented or with instrumented arthrodesis in patients with degenerative lumbar spinal s tenosis. There is uncertainty regarding the optimal use of arthrodesis and instrumentation. Methods. Two hundred seventy-two patients underg oing surgery for degenerative lumbar stenosis by eight surgeons at fou r centers were included in the study cohort. Of these, 37 had noninstr umented and 41 had instrumented arthrodesis. Logistic regression ident ified factors associated with arthrodesis. The principal out-comes-hea lth status, walking capacity, back and leg pain, and satisfaction with surgery-were assessed 6 and 24 months postoperatively with univariate and multivariate techniques, Outcomes also were assessed in a restric ted cohort of patients with at least 5 mm spondylolisthesis and/or 15 degrees scoliosis. Hospital costs were obtained from a computerized ho spital cost accounting system. Results. The major predictor of the dec ision to perform arthrodesis was the individual surgeon (P = 0.0001), Noninstrumented arthrodesis was associated with superior relief of low back pain at 6 months (P = 0.004) and 24 months (P = 0.01). This diff erence persisted in multivariate analyses, with borderline statistical significance. There were no significant differences in the other outc omes across treatment groups. Mean hospital costs of laminectomy alone and noninstrumented and instrumented arthrodesis were $12,615, $18,49 5, and $25,914, respectively (P = 0.0001). Conclusion. Findings were l imited by the small number of participating surgeons, modest sample si ze that produced P values of borderline significance, and nonrandomize d design. With these caveats in mind, the authors conclude: (1) The in dividual surgeon was a more important correlate of the decision to per form arthrodesis than clinical variables such as spondylolisthesis. (2 ) Noninstrumented arthrodesis resulted in superior relief of back pain after 6 and 24 months. (3) Instrumented arthrodesis was the most cost ly option. These results highlight the need for randomized controlled trials and cost effectiveness analyses of lumbar arthrodesis and instr umentation in patients with degenerative lumbar spinal stenosis.