Risk Factors Of Adjacent Segment Degeneration After Posterior Lumbar Inter-body Fusion

Objectives To observe postoperative occurrence and incidence rate of adjacent segment degeneration and, analysis the related influencing factors of adjacent segment degeneration through the clinical follow-up study of patients undergoing posterior lumbar inter-body fusion. Aimed at guiding clinical comprehensive consideration with the basic situation of the individual, and reasonable choice of surgical plan.Also,comprehensive assessment of the possibility of postoperative adjacent segment degeneration and the influence brought by the surgery is necessary for determining the appropriate operation. So that risk of adjacent segment degeneration after lumbar may be reduced,the patients quality of life may be improved.Methods 115 cases were selected through searching the data of patients with degenerative disease of lumbar undergoing posterior lumbar inter-body fusion in Wuxi Hospital Affiliated to Nanjing University of Traditional Chinese Medicine from from September 2012 to June 2014.Follow up through outpatient review or telephone return visit,and the follow-up time was 18-38 months, with an average of 23.5 months.Postoperative and preoperative imaging data of patients was collected in HIS system,as well as the records review of patient cases.Finally,102 patients were included in this clinical study,and imaging data of all patients was measured,and clinical symptoms consistent with adjacent segment degeneration imaging findings were recorded.Then the effects of age, sex, osteoporosis, preoperative adjacent segment disc degeneration, the number of fusion segments and the suspension fixation on adjacent segment degeneration were analyzed by Chi square test and Logistic regression analysis model.Result Adjacent segment degeneration occurred in 27 patients (26.5%),including 23 cases of simple ASD imaging degeneration and 4 cases of clinical symptoms consistent with adjacent segment degeneration imaging findings clinical symptoms consistent with adjacent segment degeneration imaging findings.All the patients with ASD occur the degeneration of the proximal segment,including 2 cases of both degeneration of proximal segment and end segment.The risk of ASD in patients with multi-segment fusion and preoperative adjacent segment disc degeneration was found to be increased by chi square test (P<0.05).The probability of occurrence of ASD in patients with preoperative adjacent segment disc degeneration was 2.134 times that of patients without preoperative adjacent segment disc degeneration,and the probability of occurrence of ASD in patients with multi-segment fusion was 1.303 times that of patients with a single segment fusion.Conclusion(1)The age, gender, and osteoporosis of patients was no significant correlation with adjacent segment degeneration,and it is not risk factor of adjacent segment degeneration.(2)The preoperative adjacent disc degeneration is the risk factors of occurrence of adjacent segment degeneration after posterior lumbar inter-body fusion,it is necessary for prevention of adjacent segment degeneration to assess adjacent segment disc degeneration before the operation comprehensively.(3)Patients with multi-segment fusion may withstand greater risk than that with a single segment fusion,and multi-segment fusion should be avoided if possible to reduce the risk of adjacent segment degeneration post operatively.