Extraforaminal microdiscectomy for upper lumbar disc herniations: minimally invasive alternative surgical approach

Background Various methods and techniques have been developed for extraforaminal decompression, particularly for far lateral lumbar disc herniation. Distinct anatomical differences are noticeable in the upper levels of the lumbar spine, which may complicate the related surgical approach. This study aimed to determine the safety and efficiency of the far lateral extraforaminal approach for the upper lumbar disc. Methods L1–2 and L2–3 migrated lumbar disc herniations were defined as upper lumbar disc herniations. Thirty-one consecutive patients with upper lumbar disk herniation who underwent extraforaminal lumbar microdiscectomy between January 2018 and March 2022 were retrospectively investigated. The patients were assessed using the interval history, follow-up lower back and leg pain visual analog scale scores (0–100 mm), the Oswestry Disability Index (%), and modified MacNab criteria. Results Thirty-one consecutive patients with upper lumbar disk herniation (20 men and 11 women) with a mean age of 52.8±10.8 years (range 31–70 years) underwent extraforaminal lumbar microdiscectomy. The preoperative and postoperative visual analog scale scores and ODI were significantly different (P < 0.001). According to the modified MacNab criteria, 23 patients showed excellent improvement, 5 showed good improvement, and 3 showed fair improvement; thus, the rate of satisfactory improvement was 90.3% at the 2-year follow-up. No patients required reoperation at the operative level during follow-up. Conclusions Extraforaminal lumbar microdiscectomy is a safe and effective minimally invasive surgical technique for treating upper lumbar disc herniation.