Imaging Criteria for the Quantification of Disc Degeneration

Lateral Lumbar Spinal Stenosis: Associations With the Oswestry Disability Index, Visual Analogue Scale, and Magnetic Resonance Imaging

Introduction Degenerative lumbar spinal stenosis is a communal problem in the sixth decade of life involving L4/L5 and L5/S1 levels. Lateral spinal stenosis is often underestimated because of no established relationship between the clinical symptoms and MRI findings. We conducted a study to establish an association between the degree of anatomical lateral stenosis, posterior disc height, and disc degeneration from MRI with the daily disability and pain severity for lateral lumbar spinal stenosis. Methods This was a cross-sectional study involving 121 patients with distinct clinical symptoms of lateral lumbar spinal stenosis evaluated from February 2018 to December 2019. The clinical data were evaluated using the Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS), while magnetic resonance imaging (MRI) was assessed qualitatively for the anatomical gradation of lateral spinal stenosis, the magnitude of posterior disc height, and the extent of disc degeneration. Statistical analysis for the correlation between posterior disc height and ODI and VAS scores was evaluated using Pearson's correlation test via SPSS version 23.0 (IBM Inc., Armonk, New York), and the association between the extent of lateral stenosis and disc degeneration on MRI with ODI and VAS scores was determined by the Fisher Exact Test via STATA version 14.0 (StataCorp LLC, College Station, Texas). The association was considered statistically significant with a P-value of less than 0.05. Results The analysis of 121 patients showed the mean age of the patients was 58.7 ± 7.1 years old. The number of female patients was higher compared to male patients, 52.9% and 47.1%, respectively. 97.5% of the patients were married or cohabiting, and 76.0% had an abnormal body mass index. The mean score of ODI and VAS was 62.2 ± 10.7% and 79.3 ± 8.6 respectively. 49.6% of the patient presented with a crippling disability with ODI assessment, while 59.5% presented with high pain intensity with VAS assessment. MRI assessment of anatomical grading lateral stenosis of L4/L5 level revealed that 45.5% of the patients had grade 2 lateral recess stenosis, 63.6% had grade 2 foraminal stenosis, and 44.6% had extraforaminal stenosis. L5/S1 level analysis showed that 43.0% had grade 2 lateral recess stenosis, 62.0% had grade 2 foraminal stenosis, and 29.8% had extraforaminal stenosis. 64.5% of patients had grade 4 disc degeneration of L4/L5 with mean posterior disc height of 7.0mm ±1.7mm while 59.5% had grade 4 disc degeneration of L5/S1 with mean posterior disc height of 6.3mm ±1.8mm. However, no statistically significant association between clinical symptoms and MRI findings was found.  Conclusions There was no significant association between the clinical symptoms of pain and disability and the MRI findings for the anatomical gradation of lateral spinal stenosis, the magnitude of posterior disc height, and the extent of disc degeneration. A comprehensive clinical evaluation remains essential for an accurate diagnosis, emphasizing the necessity of appropriately correlating MRI findings with their clinical significance.

Adjacent segment disease following Dynesys stabilization for lumbar disorders: A case series of mid- and long-term follow-ups

BACKGROUND

Radiologic adjacent segment degeneration (ASDeg) can occur after spinal surgery. Adjacent segment disease (ASDis) is defined as the development of new clinical symptoms corresponding to radiographic changes adjacent to the level of previous spinal surgery. Greater pre-existing ASDeg is generally considered to result in more severe ASDis; nonetheless, whether the ASDeg status before index surgery influences the postoperative risk of revision surgery due to ASDis warrants investigation.

AIM

To identify possible risk factors for ASDis and verify the concept that greater preexisting ASDeg leads to more severe ASDis.

METHODS

Data from 212 patients who underwent posterior decompression with Dynesys stabilization from January 2006 to June 2016 were retrospectively analyzed. Patients who underwent surgery for ASDis were categorized as group A (n = 13), whereas those who did not were classified as group B (n = 199). Survival analysis and Cox proportional hazards models were used to compare the modified Pfirrmann grade, University of California-Los Angeles grade, body mass index, number of Dynesys-instrumented levels, and age.

RESULTS

The mean time of reoperation was 7.22 (1.65–11.84) years in group A, and the mean follow-up period was 6.09 (0.10–12.76) years in group B. No significant difference in reoperation risk was observed: Modified Pfirrmann grade 3 vs 4 (P = 0.53) or 4 vs 5 (P = 0.46) for the upper adjacent disc, University of California-Los Angeles grade 2 vs 3 for the upper adjacent segment (P = 0.66), age of < 60 vs > 60 years (P = 0.9), body mass index < 25 vs > 25 kg/m² (P = 0.3), and sex (P = 0.8).

CONCLUSION

Greater preexisting upper ASDeg was not associated with a higher rate of reoperation for ASDis after Dynesys surgery. Being overweight tended to increase reoperation risk after Dynesys surgery for ASDis.

Disc Degeneration of Young Low Back Pain Patients: A Prospective 30-year Follow-up MRI Study

STUDY DESIGN

A prospective follow-up study.

OBJECTIVE

The aim of this study was to investigate whether early lumbar disc degeneration (DD) in young low back pain (LBP) patients predicts progression of degenerative changes, pain, or disability in a 30-year follow-up.

SUMMARY OF BACKGROUND DATA

MRI is an accurate method for studying degenerative changes in intervertebral discs. Decreased signal intensity (SI) can be used as indication of decreased water content. Long-term prognosis of early DD remains unclear.

METHODS

In an earlier study, 75 conscripts aged 20 years with LBP had their lumbar spine examined by MRI. At a follow-up of 30 years, the subjects were contacted; 35 of 69 filled a pain and disability questionnaire, and 26 of 35 were also reexamined clinically and by MRI. The images were evaluated for decreased SI and other degenerative changes. Association between decreased SI of a disc at baseline and the presence of more severe degenerative changes in the same disc space at follow-up was analyzed using Fisher exact test. Association between decreased baseline SI and pain/disability scores from the questionnaire was analyzed with Kruskal-Wallis H test.

RESULTS

The total number of lumbar discs with decreased SI increased from 23 of 130 (18%) to 92 of 130 (71%)-from 0.9 to 3.5 per subject during the follow-up. Distribution of DD changed from being mostly in L4-L5 and L5-S1 discs to being almost even between the four lowermost discs. Discs that had even slightly decreased SI at baseline were more likely to have severely decreased SI at follow-up, compared to healthy discs (57% vs. 11%, P < 0.001). Other degenerative changes were also more common in these discs. Severity of DD at baseline did not have a significant association with current pain or disability.

CONCLUSION

In young LBP patients, early degeneration in lumbar discs predicts progressive degenerative changes in the respective discs, but not pain, disability, or clinical symptoms.

LEVEL OF EVIDENCE

4.