CLINICAL ASPECTS OF SCIATICA AND THEIR RELATION TO THE TYPE OF LUMBAR DISC HERNIATION

Background: Little evidence exists on the diagnostic accuracy of clinical presentation in distinguishing the type of herniation in patients with lumbar disc disease. This study was undertaken to examine the correlation between clinical features and herniation type in lumbar disc hernia. Methods: One hundred and fifty consecutive candidates for lumbar discectomy were examined. The initial assessments, including location and duration of pain, neurological examination, and straight leg-raising (SLR) tests were performed by an independent observer who was unaware of the final diagnosis. Intraoperatively, all patients were assessed by a single neurosurgeon for the presence of disc protrusion or extrusion. Results: Among 90 men and 60 women (mean age: 41.4, range: 18 – 75 year), 85 patients had disc protrusion and 65 had extruded disc. Patients with radicular pain alone and those who experienced a resolution of low back pain followed by an increased severity of radicular pain were 6.5 (P < 0.002) and 10.2 (P < 0.000) times more likely to have an extruded disc, respectively. The mean preoperative duration among the group of patients with extruded disc (11 weeks) was significantly shorter than the protruded ones (18.6 weeks) (P < 0.005). Among all subjects, 103 patients showed neurological abnormalities. There was no association between the presence of neurological deficits and the type of herniation (P > 0.005). In patients with positive crossed straight leg-raising (N = 43), 33 had extruded disc and 10 had protruded disc. The positive crossed SLR test correlated significantly with the type of herniation (relative risk = 2.56, P < 0.000, and χ2 = 27.4). Conclusion: In the lumbar disc disease, there were three groups of patients: a) those with radicular pain alone, b) those who experienced an increased severity of radicular pain followed by resolution of back pain, and c) patients with positive crossed SLR test who had a high probability of harboring an extruded disc. There was no significant association between the neurological abnormalities and the type of herniation.