Clinical efficacy of unilateral biportal endoscopy in the treatment of lumbar epidural lipomatosis of different Manjila classifications

English Keywords:Lumbar epidural lipomatosis  Unilateral biportal endoscopy  Manjila classification  Minimally invasive decompression  Spinal stenosis

English Abstract:

  【Abstract】 Objectives: To investigate the early clinical efficacy of unilateral biportal endoscopy(UBE) in the treatment of lumbar epidural lipomatosis(LEL) based on the Manjila classification. Methods: A retrospective analysis was conducted on the clinical data of 16 patients with LEL who underwent UBE surgery in our hospital between June 2022 and June 2024. There were 9 males and 7 females, with an average age of 56.3±13.5 years. All patients presented with preoperative symptoms of nerve root compression, including low back pain, lower limb radiating pain, and intermittent claudication. Based on preoperative lumbar MRI findings, the specific location and extent of spinal canal stenosis were identified. The 3×3 grid method was used to assess the degree of stenosis, and the Manjila classification was applied to determine the predominant direction of fat compression, thereby guiding surgical strategy. Operative time, estimated blood loss, hospital stay, and complications were recorded. The visual analogue scale(VAS) and, Japanese Orthopaedic Association(JOA) Scores, as well as Oswestry disability index(ODI) were used to assess the degree of low back and leg pain and neurological function preoperatively, at postoperative 3d, 1 month, and final follow-up. The modified MacNab criteria were used to evaluate the overall efficacy at final follow-up. Changes in spinal canal volume were assessed by measuring the preoperative and postoperative 6-month cross-sectional area of the spinal canal(CSA-SC) on imaging. Results: The Manjila classification results were: type Ⅰ in 6 cases(moderate 4, severe 2), type Ⅱ in 7 cases(moderate 4, severe 3), and type Ⅲ in 3 cases(moderate 2, severe 1). All surgeries were successfully completed without conversion to open surgery, and no serious perioperative complications occurred. The mean operative time was 80.38±12.43min, the mean estimated blood loss was 52.81±26.39mL, and the mean postoperative hospital stay was 4.50±1.32d. The patients were followed up for 13.41±1.38 months. Postoperative VAS scores for low back and leg pain and ODI decreased significantly, while JOA scores increased significantly(P<0.05). At final follow-up, clinical scores had improved to a similarly favorable level across all three types of patients. The excellent and good rate according to the modified MacNab criteria was 87.5% for all three types of patients. Furthermore, lumbar MRI at the 6-month follow-up showed a significant increase in the CSA-SC in all patients compared to preoperative values(P<0.05), with patients in type Ⅱ and type Ⅲ showed higher improvement rates in CSA-SC than those in type Ⅰ. Symptom recurrence occurred in one patient with severe type Ⅱ LEL, which was relieved after conservative treatment. Conclusions: The UBE technique enables precise and minimally invasive decompression for LEL patients. Individualized surgical approach adjustments and spinal canal decompression based on the Manjila classification demonstrates favorable early efficacy for all types of LEL patients.