10 patients underwent surgery for migrated nucleus pulposus throughout the intraspinal and intraforaminal zones. 8 patients underwent osteoplastic hemilaminectomy and 2 patients underwent osteoplastic bilateral laminectomy using threadwire saw. The average patient age was 61 years in the 8 male and 2 female patients involved. The follow-up period varied between 2 and 35 months, with an average of 11 months.
The location of migrated nucleus pulposus was confirmed by magnetic resonance imaging and disco-enhanced CT. The L4-5 disc was the most commonly herniated level (50%), followed by L3-4 (40%), L5-S1 (10%). Selective nerve root block was performed to determine the root responsible. The roots responsible were L3 in 2 patients, L4 in 3 patients, L5 in 1 patient, and L4+L5 in 4 patients.
Postoperative results were as follows. Leg pain had recurred in all patients. The mean JOA was 13.5, compared to 7.3 pre-operatively.
This surgical exposure provides excellent visualization and preserves posterior structures.