ObjectiveTo investigate the early effctiveness of oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation via small incision Wiltse approach for the treatment of lumbar spondylolisthesis.MethodsBetween January 2016 and December 2016, 21 patients with lumbar spondylolisthesis were treated with OLIF and pedicle screw fixation via small incision Wiltse approach. There were 9 males and 12 females, aged 57-73 years, with an average age of 64.5 years. The disease duration was 24-60 months, with an average of 34.6 months. All cases were spondylolisthesis at L4 (15 cases of degreeⅠ, 6 cases of degreeⅡ); 1 case had vertebral arch isthmus, and 20 cases had spinal stenosis. Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the effectiveness before operation and at last follow-up. Before operation and at 2 days after operation, anteroposterior and lateral X-ray films and CT were taken to measure the sagittal diameter and cross-sectional area of the spinal canal, and calculate the intervertebral height and degree of spondylolisthesis. At 6 months after operation, the intervertebral fusion was evaluated by CT.ResultsThe operation time was 120-180 minutes, with an average of 155 minutes; the intraoperative blood loss was 100-340 mL, with an average of 225.5 mL. One patient had slight injury of lower endplate, 1 patient had numbness of thigh and weakness of hip flexion after operation, 1 patient had sympathetic nerve trunk injury. All the cases were followed up 12-18 months, with an average of 14.3 months. The symptoms of low back pain, leg pain, and numbness of lower limbs significantly relieved after operation, and there was no complication such as protrusion of fusion cage, screw breakage, and endplate collapse. At 2 days after operation, the intervertebral height, degree of spondylolisthesis, sagittal diameter of spinal canal, and cross-sectional area of spinal canal significantly improved compared with preoperative ones (P<0.05). At 6 months after operation, CT showed that 1 patient had poor interbody fusion (grade Ⅲ), the other 20 patients had good interbody fusion (grade Ⅰ and Ⅱ), and the interbody fusion rate was 95.2%. At last follow-up, JOA score of lumbar spine significantly increased compared with that before operation (t=24.980, P=0.000).ConclusionOLIF combined with pedicle screw fixation via small incision Wiltse approach for the lumbar spondylolisthesis has minimally invasive features, such as less trauma, fewer complications, and higher intervertebral fusion rate. It is a safe and effective method.