Efficacy of Topping-Off Surgery in Preventing Adjacent Segment Degenerative Stenosis of the Lumbar Spine: A Radiographical and Clinical Study

Abstract

Introduction Adjacent segment degeneration or disease (ASD or ASDs) has been one of the most concerned issues after fusion of the lumbar spine. To investigate the radiographical and clinical outcome of adjacent segment degeneration after topping-off (posterior lumbar interbody fusion + above segment interspinous implant) procedure, a retrospective study was conducted. Materials and Methods All lumbar spinal stenosis cases from the department of orthopedics of Beijing Chaoyang hospital that received PLIF + above segment Coflex between August 2008 and October 2012 were analyzed retrospectively. Analysis the gender, age, body mass index of all the patients was done. The X-ray films before and after surgery were measured and got some data (total lordosis, the height of disc, range of motion, lordosis, and olithesis). One-year follow-up were examined by MRI, observed the degeneration of intervertebral disc. All data used SPSS 12.0 for analysis. Results There were 32 patients in topping-off (males 21 and females 11), including (L4/5 PLIF + L5–S1 Coflex) 12 patients in group 1 and (L3/4 PLIF + L4/5 Coflex) 20 patients in group 2. Age averaged 61.5 years (range, 30–79 years) and follow-up averaged 24.6 months (range, 14–63 months). The average surgery time was 110 ± 21 minutes. The average blood loss was 401 ± 110 mL. Postoperation the ODI, JOA, and VAS score improved. There was no significant difference in the height of disc of the Coflex segment and above segment between before and after surgery. Segmental lordosis of Coflex and total lordosis were all increased significantly ( t = −1.9 and −2.0, p < 0.05). There was no significant difference in the number of the disc change of Modic grade of end plate ( p > 0.05). Conclusion Topping-off surgery is fit for the patients who have serious stenosis of lumbar spinal cord with mild and moderate stenosis of adjacent segment, which can restrict the adjacent segment's range of motion and prevent excessive olisthesis of adjacent segment in both extension and flexion, also can sustain the height of Coflex segment. It shows a good result after short-term follow-up. Topping-off surgery plays an active role in preventing the adjacent segmental degeneration.