857-864 (2007). 31. Cahill. P. et al. Lumbar spinal stenosis. part I and II. Cont.SpineSurg. 6.56-68 (2004). 32. Paden. S. D.. Davis. D. 0.. Dina. T. S.. Patrons. N. J. & Wiese'. S. W. Abnormal magnetic-resonance scans of the lumbar spew in asymptomatic subjects. A prospective investigation. J. B