Biomechanical change in adjacent segments after cervical fusion and non-fusion：a meta-analysis of second surgery rate / 中国组织工程研究

ABSTRACT

BACKGROUND:Adjacent segment disease is a long-term complication of anterior cervical decompression and fusion, and has been paid great attention recently. Cause of disease contains increased range of motion in surgery adjacent segment, intervertebral height loss and high intradiscal pressure. In the clinic, compared with fusion surgery, whether cervical non-fusion can effectively decrease the incidence of adjacent segment disease remains poorly understood. OBJECTIVE:To systematicaly assess the effects of cervical fusion and cervical non-fusion on adjacent segment degeneration. METHODS:We retrieved the randomized controled trial concerning cervical fusionversuscervical non-fusion to repair cervical syndrome in the Medline, PubMed, Embase and Cochrane databases from January 2000 to December 2013. This study compared the effects of two repair methods on adjacent segment disease and evaluated methodological quality of the included studies. A meta-analysis was performed using RevMan 5.2 software. Outcome indicators second surgery was undergone due to postoperative adjacent segment disease. RESULTS AND CONCLUSION: After screening, five randomized controled trials met the inclusion criteria. There were 1 602 patients. Al patients received surgery due to cervical syndrome. 785 cases underwent anterior decompression and fusion, and 817 cases underwent intervertebral disc replacement. 1 066 patients completed al folow-up, with a total folow-up rate of 66.54%. There were 494 patients treated with anterior decompression and fusion and 572 patients with intervertebral disc replacement. A total of 68 patients underwent second surgery due to adjacent segment disease. Total second surgery rate was 6.38% (68/1 066), including 28 cases after intervertebral disc replacement and 40 cases after anterior decompression and fusion. The grade of quality evaluation of the included studies was high, including five studies with grade A. Moreover, heterogeneity was smal (I2 = 14%). Meta-analysis results revealed that the second surgery rate of adjacent segment disease was lower after cervical non-fusion than after cervical fusion, which showed significant differences (odd ratio = 0.58, 95% confidence interval 0.35, 0.96). These results suggested that the second surgery rate of adjacent segment disease was higher after cervical fusion than after cervical non-fusion. The alterations in cervical biomechanics caused by fusion greatly affected the occurrence of adjacent segment disease.