Correlation of Canal Dimension with Neurological Status and Surgical Outcome in Lumbar PIVD: A Recent Study

Introduction: Symptomatic lumbar PIVD is major of disability and absteenism from work. The symptom of a disc herniation is determined by a variety of factors, including the level of the disc, its point, and the percentage canal compromise induced by the disc, among others. We present the findings of a prospective study on the relationship between spinal canal dimension and neurological status and surgical outcome in lumbar PIVD.. Whereas lumbar disc herniation in adult is largely secondary to degenerative disc disease as evidenced by operative findings and by routine pathological examination of specimens removed, often with large sequestrated fragments, disc herniation in adolescents is usually seen after severe injury.

Methods and Material: The research included 41 patients who were followed for an average of one year from May 2011 to December 2015. The study included patients with cauda equina syndrome, back or leg pain that persisted for more than 6 weeks despite conservative care, and patients with progressive motor weakness and leg symptoms. Patients with age > 60 years, traumatic disc prolaspe.and spondylolethesis with disc prolapse were excluded from the study. The dimensions of the spinal canal after a prolapsed disc in the AP and transverse dimension were noted On an MRI scan.Symptoms were evaluated according JOA SCORE and ODI SCORE at preoperative, 1, 3, 6, and 12 months follow up. The Pearson correlation coefficient was used to create the correlation.

Results: The patients were 37.62 years old on average. The mean anteroposterior canal dimension was 6.72mm while in transverse, it was 14.20mm in AP, mean preoperative JOA score was (7.46±3.45) and (10.75±4.26) in group 1 and 2 respectively with the p-value of 0.068 but the postoperative JOA score was almost the same (27.09±3.4) and (27.37±5.09) in both the groups with the p-value of 0.855. In transverse group, mean preoperative JOA score was (6.45±4.05) and (11.2±2.14) in group 1 and 2 respectively with the p-value of 0.004 and the postoperative JOA score was (27.09±4.78) and (28.1±3.1) in two groups with the p-value of -5.78. Only the preoperative transverse group had a significant p-value of 0.004. Mean preoperative ODI score in AP group was higher (37±7.11) in group 1 as compared to group 2(30.62±9.13) with p-value of 0.39 but the final postoperative ODI score (9.3±10.8) and (8.87±8.9) was almost the same in both groups with p-value of 0.926. Mean preoperative ODI score in transverse group was (37.27±7.55) and (31.66±8.52) in group 1 and group 2 respectively with p-value of 0.122 but the final postoperative ODI score (11.36±12.85) and (6.7±4.76) was almost the same in both groups with p-value of 0.294. Since the p-values in both groups are insignificant, it can be confidently inferred that the decrease in canal dimension is irrelevant to the patients' symptomatology.

Conclusion: Keeping in view the above findings, it can be safely concluded the canal compromise by the prolapsed disc alone is not related to the patient’s symptoms. There are other factors like position of prolapsed disc in relation to nerve root, stage of disc herniation, etc. which are important in overall symptomatology of prolapsed disc.