The analysis on short-term clinical efficacy of In-Space after decompressive laminectomy for treatment of degenerative lumbar spinal stenosis with vertebral instability

Abstract

Objective To investigate the difference of short-term clinical efficacy between decompressive laminectomy into In-Space and simple decompressive laminectomy for treatment of lumbar spinal stenosis with vertebral instability.Methods Thirty-three patients with lumbar spinal stenosis with vertebral instability admired from May 2009 to July 2010,were divided into two groups by random number table.Group A of 16 cases was treated with laminectomy decompression and placement In-Space,group B of 17 cases was treated with laminectomy decompression.Lumbar anteroposterior,lateral and flexion-extension X-ray films,preoperatively,and the follow-up were used to measure anterior and posterior disc height,foraminal height,segmental lordotic angle at surgical level.Using Oswestry disability index (ODI) and the visual analogue scale (VAS) to evaluate the clinical efficacy.Results All patients were followed up for (13.20 ± 2.91 ) months (range 6 to 21 months).The anterior disc height after operation of group A was slightly decreased compared with the preoperative(P＞ 0.05 ),the posterior disc height at 1 day after operation and foraminal height after operation of group A were significantly increased compared with the preoperative (P＜ 0.05).The anterior and posterior disc height,foraminal height of group B at 1 day,1 month,3 months after operation were no significantly different compared with the preoperative (P ＞ 0.05 ),at 6 months after operation and the end of follow-up were significantly decreased compared with the preoperative or 1 day after operation (P ＜ 0.05 ).Activity of lumbar vertebra by preoperative 9.86° ± 1.90° decreased to the end of followup 5.60° ± 2.02°in group A,while activity of lumbar vertebra by preoperative 9.89° ± 2.00°increased to the end of follow-up 10.76° ± 3.14° in group B.At the end of follow-up,lumbar back pain VAS,ODI score [ (2.02 ± 1.98 ),( 20.18 ± 18.80) scores ] of group A were significantly lower than those of group B [ (4.15 ±2.36),(30.39 ± 16.62 ) scores ],the differences were statistically significant (P ＜ 0.05 ).No patient suffered In-Space loosening,fracture and emerge.Conclusion The operation of In-Space can maintain spinal mobility and stability as well as avoiding lumbar vertebral instability,and its short-term efficacy is satisfactory. Key words: Spinal stenosis; Decompression,surgical; Dynamic stabilization system