z. J. N. et al. Predictors of surgical outcome in degenerative lumbar spinal stenosis. Spine 21.2229-2233 (1999). 85. Mackay. D. C. & Wheelwright. E. F. Unilateral fenestration in the treatment of lumbar spinal stenos's. Br. J. Neurosurg. 12. 556-558 (1998). 86. Postaochuv. F. Surgical management of lumbar