We studied 33 cases of lateral lumbar disc herniation (LLDH) retrospectively. In radiological examinations, coronary view by magnetic resonance imaging (MRI) proved most useful. Selective radiculography and root block were effective for the diagnosis of the LLDH level. Discography and CT-discography were useul for diagnosis of the occupied region. On the other hand, lateral fenestration was considered the best surgical method for LLDH because it was comparatively easy and reguired no fusion. The details of this study are as follows. We performed lateral fenestration on 19 patients. The locations of disc hernia were intraforaminal type (IF) in 4 cases, extraforaminal type (EF) in 11 cases, intara and extraforaminal type (IEF) in 5 cases. The average recovery rate of the JOA score (Japan Orthopedic Association score, Assessment of Treatment for Low Back Pain) was 97.1% for IF, 80.8% for EF, and 84.8% for IEF. The results were not significantly different, and were satisfactory. We believe that lateral fenestration is effective for not only the EF type, but for the IF and IEF types, as well.
