Abstract: Objective: To evaluate the feasibility and clinical efficacy of microendoscopic discectomy-transforaminal lumbar interbody fusion (MED-TLIF) with mobile microendoscopic discectomy (MMED) technique. Methods: The MMED include outer working canal and inner operating canal, and large working canals and endoscopic chisel were fabricated for this operation. Operation was designed as follow: the pedicles and index level were located with fluoroscopy, and a 2.5cm incision was made between pedicle punctures sites on the side with prominent symptom. Working canal was inserted and the facet was exposed, the inferior articular process and medial part of superior articular process were resected. The disc and cartilage endplates were curettage, and the intervertebral space was released and tested. The inner operating canal was removed and the interbody space was grafted and supported with suitable cage. Percutaneous pedicles screws were inserted and the residual displacement was evaluated under fluoroscopy, followed by the install of connecting rods, reduction and fivation. Fifty-six patients of lumbar stenosis with instability (32 cases) and spondylolisthesis (1 degree in 15 cases and 2 degree in 9 cases) were treated by this technique, and the index levels included L4/5 in 32 and L5S1 in 24 patients. The operation data and follow-up results were recorded and evaluated. Results: Surgery was successful in all patients, with no nerve injury or conversion to open surgery. The mean operative time was 120 min (range, 90–180 min), with a mean blood loss of 150 ml (range, 50–250 ml). The post-op X-ray and CT scans showed improvement of spinal alignment with mean reduction ratio of 72%. Patients were followed up for 12 to 36 months, the ODI score decreased from 50.1±11.2 pre-op to 5.8±5.6, VAS of lumbar decreased from 7.1±4.2 to 1.1±1.1 and VAS of leg decreased from 4.1±2.5 to 0.9±0.9 at final follow-up. The clinical results were excellent in 36 cases, good in 20 according to the MacNab scale. Conclusion: MED-TLIF can easily performed with MMED technique, with sufficient decompression and reduction, providing satisfactory results with less invasive procedure.

Key words: Microendoscopic discectomy, transforaminal lumbar interbody fusion, Percutanous fixation, Lumbar spine stenosis