Abstract
BACKGROUND: Little evidence exists on the diagnostic values of concomitant symptoms and signs in the level diagnosis of patients with lower lumbar disc herniation. We assessed the diagnostic value of the clinical presentation of fifth lumbar and first sacral root dysfunction due to disc herniation. METHODS: We examined 139 consecutive candidates for lower lumbar discectomy. A number of clinical symptom and signs referred to fifth lumbar and first sacral root dysfunction were collected for each patient by an independent observer. Intraoperatively, all patients were assessed for the level of disc herniation (gold standard). RESULTS: Among the 83 men and 56 women (mean age, 41.6 years, range, 18-75 years), 72 had L4-L5 and 67 had L5-S1 disc herniation. The sensitivity and specificity for concomitant presentation of monoradicular pain, toe weakness (dorsiflexion), normal ankle reflex and straight leg rising (SLR) positive test for the level of fourth lumbar disc herniation were 41.5% and 95.5%, respectively. Positive and negative predictive values for these symptom and signs in the fourth level were 90% and 62.7%, respectively (P<0.0001, relative risk=2.41, odds ratio=15.16). Sensitivity, specificity, positive and negative predictive values for concomitant presentation of monoradicular pain, toe weakness (plantarflexion), impaired ankle reflex and SLR positive test for the level of the first sacral disc herniation were 60.5%, 98.7%, 95.8% and 83.1%, respectively (P<0.0001, relative risk=5.68, odds ratio=113.4). CONCLUSION: The diagnostic value of clinical features of herniated fifth lumbar disc herniation is more reliable than fourth lumbar disc herniation. The value of clinical presentation in the level diagnosis of lower lumbar disc herniation is highly specific, but rather insensitive.