Axial loading of the spine during CT and MR in patients with suspected lumbar spinal stenosis.

PURPOSE: To evaluate the effect of compressive axial loading in imaging of the lumbar spine in patients with clinically suspected spinal stenosis. MATERIAL AND METHODS: A total of 84 patients were examined, 50 with CT (after intrathecal contrast administration) and 34 with MR. First the dural sac cross-sectional area (CSA) was determined with the patient in the supine psoas relaxed position (PRP). Then the CSA was determined during supine axial compression in slight extension (ACE), obtained with a specially designed loading device. A measurement error study was performed. RESULTS: A minimum difference in CSA of 15 mm2 between PRP and ACE was found to be significant. In 40/50 (80%) of CT-examined patients and in 26/34 (76%) of MR-examined patients a significant difference in CSA was found. In 25/84 (30%) of the patients there was a significant difference at more than one level. CONCLUSION: For an adequate evaluation of the CSA, CT or MR studies should be performed with axial loading in patients who have symptoms of lumbar spinal stenosis.

Midterm follow-up of young patients fused in situ for spondylolisthesis.

To evaluate the results of posterolateral fusion alone (66 patients) and combined posterolateral and anterior fusion (39 patients) in situ, 105 consecutive patients younger than 25 years of age with spondylolisthesis, retrospectively were examined clinically and radiologically. The follow-up rate was 98% after a mean of 8.2 years (range, 2.0-15.3). Pre- and postoperative progression of slip was rare (6% and 1%, respectively), and no prognostic factors were found. The definite pseudarthrosis rate was 6%. In patients with low- and high-grade slip, 67% and 88% (respectively) were satisfied at follow-up, suggesting that the indication for operative treatment in patients with low-grade slip is relative.

Radiologic progression of isthmic lumbar spondylolisthesis in young patients.

In 311 patients (160 girls and women and 151 boys and men) with lumbar spondylolysis/spondylolisthesis 30 years of age or younger at diagnosis and with at least two separate examinations available, radiographs were evaluated retrospectively to estimate the magnitude of slip progression in relation to age and to search for possible prognostic factors of progression. The mean age at diagnosis was 16.2 years, and the mean observation time was 3.8 years. Nine patients (3%) had a slip progression (defined as an increase greater than or equal to 20%). The magnitude of progression per year was low (0.6%). No prognostic factors for progression were found.

Natural history of symptomatic isthmic low-grade spondylolisthesis in children and adolescents: a seven-year follow-up study.

To evaluate the natural history of spondylolysis and spondylolisthesis, for clinical and radiological prognostic factors for progression of slip and the need for operative intervention, 47 patients with symptomatic spondylolysis or low-grade isthmic spondylolisthesis were studied retrospectively. The mean follow-up time was 7 years. Two patients (4%) had a progression of slip. Thirty percent of the patients required operation after a mean observation period of 3.7 years. At follow-up, 83% of the nonoperatively treated patients were rated excellent or good. No prognostic factor for progression of slip or need for future operative treatment was found.