Lumbar nerve root compression at the intervertebral foramina caused by arthritis of the posterior facets

Occult lumbar spinal stenosis

Twenty-eight patients presenting with low back pain, associated with sciatic or femoral neuropathy, were found to have lateral recess stenosis occurring as a result of hypertrophy of the facet joints, with preservation within normal limits of the sagittal AP diameter of the lumbar canal. Pathology was believed to be traumatic in origin, and the variable nature of the adhesions suggested recurrent inflammation; the hypertrophy of the facet joints may have been the result of traumatic inflammatory hyperaemia. Radiological investigations were unhelpful. The diagnosis of the condition was made at the time of surgical exploration by the findings of alteration of the facet joints, adhesions and fixity of the nerve roots, normal sagittal AP diameter of the canal, and absence of other significant lesions. Gratifying results were obtained with decompression by wide laminectomy with excision of overhanging facet joints and release of adhesions.

Degenerative lumbar spondylolisthesis with an intact neural arch (pseudospondylolisthesis)

Twenty patients treated for degenerative spondylolisthesis with an intact neural arch principally at the L4-5 interspace had neural compression caused by dislocation of the vertebral bodies and intrusions of lamina and enlarged, arthrotic facets into a stenotic spinal canal. The resulting "pincer" effect caused complete or partial block demonstrable on myelography, with nerve root and cauda equina compression. Most of the patients were women aged 45-84 years. Seven had neurogenic claudication. The majority had unrestricted straight-leg raising, and no signs of acute neural entrapment were seen as in patients with a herniated disc. Absent ankle reflexes, and weakness and atrophy of the anterior tibial muscle group were common, while sensation was relatively undisturbed. Treatment consisted of liberal laminar decompression including foraminotomy and medial or total facetectomy. Good-to-excellent results were obtained, and no patient was made worse by the procedure.

Surgical treatment of nerve root compression caused by scoliosis of the lumbar spine

✓ Effective relief of radicular pain and recovery of function is reported in four elderly patients with lumbar scoliosis following surgical decompression of the lateral recesses of the spinal canal. The operation includes laminectomy or hemilaminectomy with unroofing of the lateral recesses and foramina by medial facetectomy or facetectomy. The patients tolerated surgery without morbidity, were walking within 2 or 3 days, and recovered without incident. The pathological anatomy and operative criteria are discussed.