Short-term clinical outcome and radiographic assessment of indirectly decompression of oblique lateral interbody fusion for degenerative lumbar spinal stenosis

Objective To investigate the short-term clinical outcome and radiographic assessment of Oblique Lateral Interbody Fusion to indirectly decompress for the degenerative lumbar spinal stenosis with or without lumbar spine instability. Methods All of 15 patients with diagnosis of degenerative lumbar spinal stenosis with or without lumbar spine instability (7 males and 8 females, age from 36y to 86, mean age 53.5±15.2 y) were treated with OLIF surgery in our spine surgery center. The main symptoms included lumbar pain with unilateral or bilateral leg pain or intermittent claudication. The Visual analogue scale (VAS), Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) and SF-36 scores were used to assess the clinical effect pre and post-operatively while radiographic assessments were compared as well as comprehensive evaluation of the radiography, MRI, and CT images. Results All patients were followed up for an average of 12.5 (6-21) months. And all the patients enjoyed alleviation of symptoms although varying in extent. The radiographic results showed satisfactory indirect decompression of the neuro-elements, as well as reduction of the lumbar spine. The DH, VH and FH increased by 3.6mm, 4.8mm and 5.7mm respectively. The foraminal area (FA) and canal area (CA) enlarged by 44.2mm2 and 24.8mm2. The canal diameters (CD) and disk-flavum ligamentum space (DLFS) increased by 2.5mm and 2mm respectively. The foraminal diameters (FD) increased by 0.3mm, but there was not significantly different. The segment angle and lumbar lordosis angle were partially restored after operation, and the angle increased by 14 ° and 13.6 °respectively. One of the patients had a transient paresthesia and mild weakness of muscle when hip flexor and recovered within 3 months. Another one case encountered serious back pain after a month and alleviated after reoperation with PPF. Conclusion OLIF can provide a satisfactory outcome for the patients with degenerative lumbar spinal stenosis through indirectly decompression, which can increase the disc height, foramen height, canal diameter and disk-flavum ligamentum space. Key words: Lumbar vertebrae; Spinal stenosis; Spinal fusion