Effectiveness of Microscopic Tubular Discectomy for Improved Pain and Mobility in Far Lateral Lumbar Disc Herniation: A Systematic Review.

Far lateral lumbar disc herniation (FLLDH) is a subtype of lumbar disc herniation marked by severe radicular and lower back pain, often accompanied by sensory and motor dysfunction. Microscopic tubular discectomy (MTD) is a contemporary minimally invasive approach for treating FLLDH, yet its superiority over conventional discectomy remains inconclusive. The purpose of this systematic review was to assess the effectiveness of MTD in improving pain and mobility for FLLDH patients. A secondary aim was to assess the safety of MTD. Primary outcome measures were patient-reported pain, assessed using a visual analog scale (VAS), patient-reported mobility, assessed using the Oswestry Disability Index (ODI), and scores on the Modified MacNab criteria clinical assessment. Secondary outcome measures were mean blood loss, operation duration, hospital stay, reherniation rate, reoperation rate, and any peri- or postoperative complications. MEDLINE, Embase, and Scopus were searched for empirical studies on MTD for FLLDH, reporting pain or mobility outcomes. Data extracted included study design, participant characteristics, pre- and postmean scores for pain and mobility, blood loss, operation time, hospitalization duration, reherniation rate, and complications. Articles were quality appraised using Joanna Briggs Institute (JBI) quality appraisal tools. Of 271 articles identified, 15 were included. Preoperative leg pain scores ranged from 5.5 to 8.6, and postoperative scores ranged from 1.2 to 3.8. For lower back pain, preoperative scores ranged from 2.4 to 7.6, with postoperative scores from 1 to 4.8. Seven studies assessed mobility using the ODI, reporting significant improvements; pre-operative scores ranged from 30.6 to 56.7, and postoperative scores ranged from 5.5 to 30.3. Seven studies used the Modified MacNab criteria, reporting excellent outcomes in 18.2%-71% of patients, good in 23%-54.5%, fair in 0%-18.2%, and poor in 0%-18%. Mean blood loss ranged from 30 to 70 mL, mean operation times from 43 to 126 min, and average hospital stays were, on average, ≤ 4 days. Reherniation was minimal, and the reoperation rate was low. Complications were rare, primarily transient neuropraxic symptoms. This review comprehensively synthesized empirical research on the effectiveness and safety of MTD for treating FLLDH. Overall, the findings indicate that MTD can reduce pain and improve mobility in patients with FLLDH, but limited sample sizes, variable follow-up periods, and a lack of controlled studies constrain definitive conclusions about MTD's superiority over other discectomy techniques. PROSPERO registration number: CRD42023443900.