Lumbar spinal stenosis. A retrospective study of 163 cases in southern Sweden.

I assessed the incidence of lumbar spinal stenosis as well as the frequency of severe neurological symptoms and signs based on patients seen in 2 orthopedic departments. The annual incidence in Malmõ, 1982-1986, was 59 and in the period 1987-1991, 47 per million inhabitants. In Växjö, 1987-1991, the annual incidence was 45 per million. Severe neurological symptoms were few. Reduced EHL power and peroneal paresis were the most prevalent signs and were found in 13 and 12 percent, respectively, of all 163 patients. 1 patient had bladder dysfunction, 1 had impotence and 2 had a cauda equina syndrome.

The natural course of lumbar spinal stenosis.

The course of 32 untreated patients with spinal stenosis was studied. The mean patient age was 60 years, and the mean period of observation was 49 months. About 75% of the patients had spinal claudication. In the follow-up survey, the same number of patients had claudication, but the symptoms were milder. In estimation by visual analog scale, symptoms in 70% of the cases were unchanged, 15% showed improvement, and 15% worsened. No proof of severe deterioration was found after four years, and expectant observation may be an alternative to surgical treatment.

The effect of decompression on the natural course of spinal stenosis. A comparison of surgically treated and untreated patients.

The clinical course of 19 untreated patients with spinal stenosis (mean age, 60 years) was compared with that of 44 patients treated surgically (mean age, 65 years). The time of follow-up was 31 and 53 months, respectively. About 80% of the patients had neurogenic intermittent claudication. In the follow-up, one third of the treated and one half of the untreated patients still had neurogenic claudication. By visual analogue-scale estimation, 60% of those treated surgically and 33% of the untreated patients felt better. Fifty-eight percent of the untreated patients were unchanged. Neurophysiologic changes showed progression in almost all cases; it was more pronounced in the treated patients. No proof of severe deterioration was found in the untreated patients, and observation for 2-3 years seems to be a good alternative to surgery.

Preoperative and postoperative instability in lumbar spinal stenosis.

Sixty-one patients operated on for spinal stenosis, without a fusion, were studied retrospectively. Preoperative instability, as revealed by functional myelography, was found to predict a poor prognosis (P less than 0.01). Women had less favorable results (P less than 0.05). The "slipping" group was significantly more often radically decompressed than the "nonslipping" group (P less than 0.01). Postoperative slipping was found in 26 patients, significantly more often in those with unsatisfactory results (P less than 0.001).

Neurophysiologic investigation of patients with spinal stenosis.

To study the role of neurographic, electromyographic, and psychophysic examinations when diagnosing spinal stenosis, the authors studied 64 patients (mean age, 64 years) with myelographically verified spinal stenosis. Sixteen patients showed signs of total occlusion of the dural sack. Twenty-four patients with spinal claudication but with normal myelograms constituted a comparison group (mean age, 57 years). Normal reference values were obtained from 50 men aged 28-63 years. In spinal stenosis with total occlusion, bilateral neurogenic changes were registered in 87.5%, without total occlusion in 81%, and in spinal claudication with a myelogram of normal width in 29%. The corresponding frequencies of multisegmental EMG abnormalities were 94%, 75%, and 21%, respectively. Motor conduction velocity was normal in spinal stenosis except in cases with total occlusion. High thresholds were found to vibration and temperature changes in the legs, much like in patients with polyneuropathy. However, polyneuropathy was found in only a minority of the patients.

Postoperative instability after decompression for lumbar spinal stenosis.

Slipping after decompression for myelographically verified spinal stenosis (AP diameter less than or equal to 11 mm) was studied in 45 patients (32 men and 13 women). Mean age at the time of operation was 64 years. Mean time of postoperative observation was 46 months. The results in 29 patients were excellent or good and in 16 unchanged or worse. Degenerative spondylolisthesis was found in 20 patients and acquired spinal stenosis in 25. Postoperative slipping was seen in 18 patients. Seven belonged to the good group. A significant increase of patients with slipping was seen in the poor group (P less than 0.01). An enhanced risk of further slipping was seen in degenerative spondylolisthesis (P less than 0.01), but it did not influence the result of the operation. The radicality of the operation was about equal in both the good and poor groups and in the groups with or without postoperative slipping. A general decrease of the disc heights after operation was seen in all groups but was not significant in the poor group.

Myelography in the elderly and the diagnosis of spinal stenosis.

To evaluate the width of the spinal canal when diagnosing spinal stenosis, 91 patients older than 59 years of age when undergoing myelography were studied. Using a sagittal diameter of 11 mm as border for the diagnosis of spinal stenosis, it was found that 31 of the 66 patients with spinal claudication, suspicion of spinal claudication and sciatic pain fulfilled this criterion and that 3/25 of the control group and those with atypic symptoms had a sagittal diameter of 11 mm or less. Five patients showed a complete block on the myelogram, and all of them had a typical spinal claudication. The spinal canal will narrow with age in asymptomatic patients as well, and the myelographic stenosis in elderly patients is not always equivalent to a clinical diagnosis of spinal stenosis.

Bone mineral content and bone mass in patients with spinal stenosis.

The bone mineral content in the distal end of the forearm was measured in 45 patients with spinal stenosis. In men, there was a significant increase in bone mineral content but only in the distal end of the forearm, where the measurement included mainly trabecular bone. The cortical bone more proximally in the forearm did not deviate in this respect nor could any differences be found in the small group of women included in the study. The implications are that an increased bone mineral content indicative of a greater than average bone mass may be one factor in the pathogenesis of spinal stenosis.

Diffuse idiopathic skeletal hyperostosis (DISH) causing spinal stenosis and sudden paraplegia.

Neurologic complications due to spinal cord compression developed in a patient with diffuse, idiopathic skeletal hyperostosis (Forestier's disease) originally mistaken for ankylosing spondylitis. Emergency laminectomy stopped progression of the symptoms and resulted in slow improvement.

Analysis of operated cases with lumbar renal stenosis.

Twenty-seven patients with spinal stenosis all diagnosed at the surgical exposure and treated with decompression are analysed. The material is divided into three groups according to the preoperative symptoms, those with claudication, those with back and leg pains and those with mixed symptoms. All were myelographed. The radicality of the decompression varied. Excellent and good results were obtained in a total of about 60 per cent. No difference, however, was seen between the three groups. A positive myelography (AP diameter less than 11 mm) was found in all cases with excellent and good results. The postoperative extent of the decompression was studied with a CT-scanner. Here a correlation was found between the range of decompression of the lateral recess and the result of the operation. Also the results seemed to be better with a shorter duration of the symptoms preoperatively.