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Clinical and radiographic characteristics of upper lumbar disc herniation: ten-year microsurgical experience.

Upper and lower lumbar disc herniation apparently have different background, symptoms, and operative results. This retrospective study reviewed the clinical records of 403 patients (409 discs) who underwent lumbar microdiscectomy performed by different surgeons at our institute between 1999 and 2009. The 290 male (72.0%) and 113 female (28.0%) patients were aged from 19 to 77 years (mean 44 years). Demographics, symptoms, and static and dynamic radiographic and magnetic resonance images obtained at the L1-2, L2-3, L3-4, L4-5, and L5-S1 intervertebral levels were analyzed. Of the 409 herniations, 3 were at L1-2, 9 at L2-3, 21 at L3-4, 166 at L4-5, and 210 at L5-S1. The mean age at herniation at L1-2 and L2-3 levels was 55.7 years. Patients with herniation of discs at L3-4 or above were significantly older than patients who suffered herniation at L4-5 or below (p < 0.0001), and the incidence of urinary disturbance was significantly higher in patients with herniation at L1-2 and L2-3 levels (p = 0.0013). The incidence of degenerative scoliosis was significantly higher in patients with herniation at L1-2 and L2-3 than in those with herniated discs at L3-4 or below (p < 0.0001). Patients with upper lumbar disc herniation were older and manifested a higher incidence of urinary disturbance. A high incidence of degenerative scoliosis was noted in the course of prolonged degenerative processes.