The clinical outcome of the treatment of isthmic spondylolysis with Smiley face rod fixation system

English Keywords:Lumber spine  Isthmic spondylolysis  Smiley face rod fixation system

English Abstract:

  【Abstract】 Objectives: To investigate the clinical outcome of Smiley face rod fixation system for lumbar isthmic spondylolysis. Methods: From January 2016 to June 2017, 18 patients with isthmic spondylolysis were treated with smiley face screw-rod fixation system. There were 13 males and 5 females, with an average age of 28.2±3.2(25-32) years old. The average disease duration was 16.3±5.7(7-24) months. L5 isthmic spondylolysis was involved in all cases. All patients had been followed up at 3 months and 1 year after surgery. The preoperative and postoperative visual analogue scale(VAS) and Oswestry disability index(ODI) were compared. The X-ray and CT scan were evaluated to analyze the change of range of motion in the lumber spine and the bony fusion rate. Results: The mean operation time was 90.0±24.1 minutes. The average blood loss was 140±15ml. The average follow-up was 18.5±5.0(12-24) months. The VAS at 3 months after operation was 3.0±1.2, and the ODI was (17.2±4.5)% respectively, which showed significant differences compared with the preoperative ones[7.3±2.5 and (67.0±15.1)％](P＜0.05). The VAS and ODI at 1 year after operation were 1.0±0.6 and (9.1±5.3)%, which showed significant differences compared with 3 months postoperation(P＜0.05). The range of motion between L5 and S1 was 13.1°±2.1° and the incidence of lumbar instability was 83.3%(15/18) preoperatively; it was 9.3°±1.6° and 11.1%(2/18) postoperatively, and there was statistic difference(P＜0.05). All patients achieved bone fusion in the isthmic defect 1 year after operation. Conclusions: The Smiley face rod fixation is a reliable treatment for lumbar spondylolysis with the advantage of minimal invasive, less nerve interference, and to restore normal anatomical structure, maintain the lumbar spine stability.