J. Neurosurg. / Volume 81 / November, 1994 699 J Neurosurg 81:699–706, 1994 OW -back pain constitutes a major socioeco- nomic and medical problem in the United States. In 1984, low-back pain cost an estimat- ed $16 billion and disabled 5.4 million Americans. 8 In the workforce alone, low-back pain accounts for an estimated 10 million sick days per year. 24 A growing proportion of low-back surgery is performed on the elderly, most often for decompression of degenerative lumbar spinal stenosis. In fact, it is estimated that in 1987, one of every 1000 persons over the age of 65 underwent a lumbar laminectomy. As the incidence of lumbar degenerative disease and its associated costs multiply, evaluating the effi- cacy of surgical treatment becomes increasingly important. Data exist that document clinical outcome after decompressive laminectomy for spinal stenosis, but the information is difficult to interpret because of poorly defined outcome assessment, inadequate cate- gorization of outcome data, vague data sources, incomplete follow-up evaluations, and inherent observer bias. 38,39 We present a comprehensive clinical and radi- ographic investigation of 119 patients who underwent decompressive lumbar laminectomy for spinal steno- sis in our metropolitan area over a 7-year period between 1983 and 1990. The study is divided into two parts: clinical outcome and radiographic changes. Clinical Material and Methods Patient Selection Criteria We performed a review of all patients who under- went decompressive lumbar laminectomy by a neuro- surgeon in Washtenaw County, Michigan between July, 1983 and July, 1990. Patients were selected from two hospitals: the University of Michigan Hospital and St. Joseph Mercy Hospital. After obtaining insti- tutional review board approval for the study of human subjects, hospital computers generated a list of 583 patients whose discharge diagnosis consisted of lum- bar spinal stenosis with an operative code of lumbar Outcome after laminectomy for lumbar spinal stenosis Part I: Clinical correlations GERALD F. TUITE, M.D., JOSEPH D. STERN, M.D., STEPHEN E. DORAN, M.D., STEPHEN M. P APADOPOULOS, M.D, JOHN E. MCGILLICUDDY , M.D., DOTUN I. OYEDIJO, B.S., SUSAN V. GRUBE, R.N., CRAIG LUNDQUIST , M.D., HOLLY S. GILMER, M.D., M. ANTHONY SCHORK, PH.D., STEVEN E. SWANSON, M.D., AND JULIAN T. HOFF , M.D. Section of Neurosurgery and Department of Radiology, University of Michigan Hospital; Department of Biostatistics, School of Public Health, University of Michigan; and Department of Neurosurgery, St. Joseph Mercy Hospital, Ann Arbor, Michigan  All patients who underwent decompressive lumbar laminectomy in the Washtenaw County, Michigan metro- politan area during a 7-year period were studied for the purpose of defining long-term outcome, clinical correlations, and the need for subsequent fusion. Outcome was determined by questionnaire and physical examination from a cohort of 119 patients with an average follow-up evaluation interval of 4.6 years. Patients graded their outcome as much improved (37%), somewhat improved (29%), unchanged (17%), somewhat worse (5%), and much worse (12%) compared to their condition before surgery. Poor outcome correlated with the need for additional surgery, but there were few additional significant correlations. No patient had a lumbar fusion during the study interval. The outcome after laminectomy was found to be less favorable than previously reported, based on a patient ques- tionnaire administered to an unbiased patient population. Further randomized, controlled trials are therefore neces- sary to determine the efficacy of lumbar fusion as an adjunct to decompressive lumbar laminectomy. KEY WORDS • lumbar spine • spinal stenosis • low-back pain • fusion  decompressive lumbar laminectomy • outcome L