intertransverse process arthrodesis prospective study comparing decompression with decompression and Degenerative lumbar spondylolisthesis with spinal stenosis. A

Fifty patients who had spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied clinically and radiographically to determine ifconcomitant intertransverse-process arthrodesis provided better results than decompressive laminectomy alone. There were thirty-six women and fourteen men. The mean age of the twenty-five patients who had had an arthrodesis was 63.5 years and that of the twenty-five patients who had not had an arthrodesis, sixty-five years. The level of the operation was between the fourth and fifth lumbar vertebrae in forty-one patients and between the third and fourth lumbar vertebrae in nine patients. The patients were followed for a mean of three years (range, 2.4 to four years). In the patients who had had a concomitant arthrodesis, the results were significantly better with respect to relief of pain in the back and lower limbs. Degenerative lumbar spondylolisthesis was apparently first described in the German literature, as pseudospondylolisthesis, by Junghanns23 in 193 1 , and in the Englishlanguage literature by Macnab29 in 1950. The modern concept of degenerative spondylolisthesis was described by Newman in 1955; however, the operative management of this disorder when accompanied by spinal stenosis has remained controversial, despite a clearer understanding of its pathogenesis and pathology’ ,6,1417,24,26,43#{149} Some authors have reported satisfactory results with decompressive laminectomy alone5’79”2”9’ , while others have advocated that a spinal arthrodesis be done concomitantly with the decompression2’4”2”6’242839’49. It is difficult to compare these series because of differences in the patient populations, operative procedures, surgeons, postoperative management, grading of results, and levels of the spine at which the operation was done. Therefore, the indications for concomitant arthrodesis with decompressive laminectomy in the operative management of patients who have degenerative lumbar spondylolisthesis and spinal stenosis have remained unclear. To determine these indications, a prospective study was performed to compare the results of decompression alone * No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject ofthis article. No funds were received in support of this study. t Read in part at the Annual Meeting of the International Society for the Study of the Lumbar Spine, Boston, Massachusetts, June 17, 1990. t Suite 100, 16800 West Twelve Mile Road, Southfield, Michigan 48076-2176. with those of concomitant intertransverse-process arthrodesis at the level of the decompression for the management of degenerative spondylolisthesis at a single level associated with lumbar spinal stenosis. Materials and Methods Fifty consecutive patients met the criteria for inclusion in the study: a clinical diagnosis of degenerative spondylolisthesis and spinal stenosis, with symptoms that had been