Clinical presentation and anatomic position of L3-L4 disc herniation: a prospective and comparative study

OBJECTIVE: A prospective, controlled cohort study was conducted to assess the anatomic transverse location and clinical presentation of L3-L4 disc herniation compared with lower lumbar levels. METHODS: This study prospectively identified 37 patients diagnosed with L3-L4 disc herniation (study group) and 52 patients diagnosed with L4-L5 and L5-S1 herniation (control group). The following clinical data were collected: age, femoral stretch test, motor strength, sensation, and deep tendon reflexes. The anatomic transverse location of the disc fragments was assessed by computed tomography or magnetic resonance imaging and was classified as either central, posterolateral, foraminal, or far lateral. RESULTS: The patients in the study group were older than the patients in the control group, and neurologic deficit was more common. The transverse location was foraminal and extraforaminal in 59% of the study group compared with 27% of the control group. These differences were statistically significant. CONCLUSIONS: The incidence of foraminal and far lateral disc herniation is significantly higher at the L3-L4 level compared with lower lumbar levels. When examining an older patient complaining of thigh pain, special attention should be given to the quadriceps strength, patellar reflex, and femoral stretch test. The L3-L4 foraminal and extraforaminal area should be assessed carefully.