The impact of prolapse to canal ratio (PCR) in cauda equina syndrome outcomes and operative management.

Abstract

This study aimed to evaluate the prolapse to canal ratio (PCR) and its long-term impact on outcomes in cauda equina syndrome (CES). A 5-year retrospective cohort study was conducted across two neurosurgical centers, including adult patients diagnosed with CES due to herniated lumbar discs, treated with laminectomy and/or discectomy, with available radiological data and follow-up. PCR was calculated as the proportion of the disc prolapse cross-sectional area to the total spinal canal area. MRI scans were independently analyzed by two investigators, with random verification by a third. Patient demographics, symptoms, treatment, and follow-up data were also collected. Among 137 patients, cohorts were divided using a PCR cut-off of 0.5. Patients with PCR > 0.5 were significantly more likely to have persistent symptoms at follow-up (OR 3.93, CI 2.25-7.34, p < 0.0001). This risk increased with higher PCR thresholds (> 0.75 and > 0.8). PCR > 0.5 also predicted a greater likelihood of requiring a full laminectomy over minimally invasive approaches (OR 2.14, 95% CI 1.3-3.6, p < 0.005). Lower PCR (< 0.5) was associated with reduced complication rates and shorter hospital stays. PCR is a valuable predictor of persistent pain and functional deficits following CES surgery and could be used to guide patient counseling before surgical intervention.