THE ETIOLOGY OF SPONDYLOLISTHESIS

[The operative treatment of the spondylolisthesis with compression screws (author's transl)]

The author gives account of a direct osteosynthesis--joining the defect of the interarticular part--made in case of spondylolisthesis in his department. They carry out the operation having modified the method of Buck as they use A-O malleolar compression screw instead of all threaded screw. Applying compression screws the author can ensure a successful osteosynthesis in case of a greater vertebral displacement. This method widens the indication area of the operation. The adventage of the operation over other ones made in spondylolisthesis is the fact that after the wound-healing the patient can get up and the lumbar spine will not be limited in motion. The operation was made in 16 cases until now and operative complication was not observed. They propose to make this operation as early as possible in case of definite spondylolisthesis to prevent the development of further progression.

Lumbosacral fracture-dislocation: a case managed conservatively, with return to heavy work

A 41-year-old agricultural sustained a lumbosacral fracture-dislocation when a tree fell across his back. The initial anterior displacement of half the depth of the body of L5 progressed to three-quarters of the body over a 2-year period. Neurological deficit was minimal and the management was conservative. Spontaneous arrest of the displacement occurred by anterior sacral buttressing and the patient has returned to his previous heavy work.

The spine in sport and veteran military parachutists

Spinal injuries and symptoms were studied in 109 ex-military parachutists and 112 sport (free fall) parachutists by means of postal questionnaires. 46 ex-military parachutists aged 50 years or over had a radiological examination of the lumbar spine and 58 sport parachutists had a radiological examination of the cervical spine as part of the survey. A history of back pain was significantly (P<0.01) associated with body weight in sport parachutists but not with the number of descents or with the subject's age. In the older ex-military group neither age, weight, nor the number of descents was significantly associated with backache. Of those ex-military parachutists x-rayed, 10 (21.7%) were found to have vertebral body fractures (most frequently at D12), and 8 of these were unaware of these lesions. Vertebral fractures caused no disability and did not permanently curtail parachuting activities in either the sport or ex-military group. Of the ex-military parachutists x-rayed, 84.7% had lumbar disc degeneration of all grades of severity, 17.4% had moderate changes, and 10.8% had severe changes. The frequency of moderate and severe disc degeneration was significantly related to age but not to body weight or to the number of descents. Spondylolysis was found in 2 subjects (4.3%) and spondylolisthesis unassociated with spondylolysis in 4 (8.7%). Spondylolisthesis was always associated with a history of back pain.A low prevalence of radiological cervical intervertebral disc degeneration of all grades of severity of 8.7% was found among the free fall parachutists (mean age 33 years). 2 cases of cervical vertebral body fracture were seen, one related to a parachute landing injury and the other to a parachute opening injury. This study does not implicate parachuting as a cause of intervertebral disc degeneration, either cervical or lumbar, nor as a cause of spondylolysis or spondylolisthesis. Serious long-term disability from pain appears to be uncommon among parachutists despite the frequency of the spinal trauma they sustain.

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.

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

✓ The authors report their experience with 12 cases in which the roots of the sciatic nerve were compressed at the intervertebral foramina by degenerative arthritis (arthrosis) of the posterior facets, and in which foraminotomy and facetectomy brought relief of pain. Patients with disc narrowing, spondylolisthesis, and transitional vertebrae place unusual stress on the posterior facets. This may lead to hypertrophy and the development of marginal osteophytes that project downward with eventual constriction of the intervertebral foramen and entrapment of the nerve root. Such alterations are common in patients over 40, and when found in the presence of unremitting sciatic pain without evidence of a herniated disc or other etiology, a causal relationship must be considered.