Objective To analyze the effectiveness of combined treatment of lumbar spondylolisthesis with MED, Quadrant, and Sextant-R systems. Methods Between August 2006 and June 2011, 35 patients with lumbar spondylolisthesis were treated, including 11 cases of isthmic spondylolisthesis and 24 cases of degenerative spondylolisthesis. There were 25 males and 10 females, with a mean age of 55 years (range, 33-71 years). The mean disease duration was 37 months (range, 8-75 months). Spondylolisthesis occurred at L4, 5 level in 21 patients and at L5, S1 level in 14 patients. According to Meyerding classification, 35 cases were rated as dergee I. The minimally invasive surgeries were performed by paraspinal muscle approach; Quadrant system was used for decompression and fusion at severe side, MED system for windowing of lamina at mild side, and Sextant-R system for fixation and reduction. Visual analogue scale (VAS) score was used to evaluate pain, Oswestry disability index (ODI) to evaluate clinical outcomes, spondylolishesis ratio and intervertebral height to evaluate spondylolisthesis reduction. Results Lumbar continuous thin layer CT at postoperation showed that no pedicle screw invaded spinal canal and intervertebral fusion device was at good position. Incisions healed by first intention. All patients were followed up 18-38 months (mean, 26 months). All patients got bone fusion and had no internal fixation failure by radiologic examination at 1 year after operation. Low back pain was relieved, lumbar function improved obviously, and satisfactory reduction of spondylolisthesis was obtained. At 2 weeks and 1 year after operation, the VAS score, ODI score, spondylolisthesis ratio, and intervertebral height were significantly improved when compared with preoperative ones (P lt; 0.05). VAS score and ODI score showed significant differences (P lt; 0.05) between at 2 weeks and 1 year after operation. Spondylolisthesis ratio and intervertebral height showed no significant difference (P gt; 0.05) between at 2 weeks and at 1 year after operation. Conclusion Minimally invasive surgical management for lumbar spondylolisthesis via MED, Quadrant, and Sextant-R systems is a safe and effective surgical technique. However, its indications should be well considered.
Objective To explore the feasibility and the effectiveness of the accurate placement of lumbar pedicle screws using three-dimensional (3D) printing navigational templates in Quadrant minimally invasive system. Methods The L1-5 spines of 12 adult cadavers were scanned using CT. The 3D models of the lumbar spines were established. The screw trajectory was designed to pass through the central axis of the pedicle by using Mimics software. The navigational template was designed and 3D-printed according to the bony surface where the soft tissues could be removed. The placed screws were scanned using CT to create the 3D model again after operation. The 3D models of the designed trajectory and the placed screws were registered to evaluate the placed screws coincidence rate. Between November 2014 and November 2015, 31 patients with lumbar instability accepted surgery assisted with 3D-printing navigation module under Quadrant minimally invasive system. There were 14 males and 17 females, aged from 42 to 60 years, with an average of 45.2 years. The disease duration was 6-13 months (mean, 8.8 months). Single segment was involved in 15 cases, two segments in 13 cases, and three segments in 3 cases. Preoperative visual analogue scale (VAS) was 7.59±1.04; Oswestry disability index (ODI) was 76.21±5.82; and the Japanese Orthopaedic Association (JOA) score was 9.21±1.64. Results A total of 120 screws were placed in 12 cadavers specimens. The coincidence rate of placed screw was 100%. A total of 162 screws were implanted in 31 patients. The operation time was 65-147 minutes (mean, 102.23 minutes); the intraoperative blood loss was 50-116 mL (mean, 78.20 mL); and the intraoperative radiation exposure time was 8-54 seconds (mean, 42 seconds). At 3-7 days after operation, CT showed that the coincidence rate of the placed screws was 98.15% (159/162). At 4 weeks after operation, VAS, ODI, and JOA score were 2.24±0.80, 29.17±2.50, and 23.43±1.14 respectively, showing significant differences when compared with preoperative ones (t=14.842,P=0.006;t=36.927,P=0.002;t=–36.031,P=0.001). Thirty-one patients were followed up 8-24 months (mean, 18.7 months). All incision healed by first intention, and no complication occurred. During the follow-up, X-ray film and CT showed that pedicle screw was accurately placed without loosening or breakage, and with good fusion of intervertebral bone graft. Conclusion 3D-printing navigational templates in Quadrant minimally invasive system can help lumbar surgery gain minimal invasion, less radiation, and accurate placement.