Clinical outcomes of lumbar disc herniation treated with microdiscectomy.

Microdiscectomy was performed on 75 patients (54 males and 21 females with an average age of 35.0 years at operations) diagnosed with lumbar disc herniation. The disc herniations were located as follows: L1-2; 1, L2-3; 2, L3-4; 9, L4-5; 46, and L5-S1; 17. All patients exhibited herniation at a single level. The average follow-up period was 64.4 months. The postoperative outcomes were evaluated according to the Japanese Orthopaedic Association scoring system for lumbar disease and Hirabayashi’s improvement rate. Postoperatively, the average JOA score improved from 12.1 to 26.7 points. Hirabayashi’s improvement rate was 86.4%. A recurrence of same level disc herniation was observed in 3 patients. We conclude that microdiscectomy provided satisfactory postoperative outcome in majority cases. Average intraoperative blood loss was 36.5g. Postoperatively, only 6.7% complained of low back pain, suggesting that this procedure was less invasive. Microdiscectomy has some problems such as a postoperative treatment program and possible recurrence of herniation. However, since microdiscectomy is less invasive and obtains satisfactory postoperative outcomes, it is still considered to be an effective procedure.