Risk factors and influence on clinical efficacy of cage subsidence after stand-alone oblique lateral interbody fusion in lumbar spine

English Keywords:Degenerative lumbar spine disease  Oblique lateral interbody fusion  Risk factors  Cage subsidence

English Abstract:

  【Abstract】 Objectives: To explore the risk factors of cage subsidence after stand-alone-oblique lateral interbody fusion(SA-OLIF) in the treatment of lumbar degenerative diseases(LDD) and the influence of cage subsidence on clinical efficacy. Methods: The clinical data of 89 LDD patients who underwent SA-OLIF surgery in our hospital from January 2018 to October 2021 were analyzed retrospectively. According to the loss value of disc height(DH) one year after operation, the patients were divided into two groups: cage subsidence group(≥2mm, n=17) and cage non- subsidence group(<2mm, n=72). The general data of the patients including age, sex, body mass index(BMI), smoking status, hormone use, disease type, and osteoporosis, and operation related data such as operative duration, intraoperative blood loss, operation segment, number of fusion segment, and cage height were collected and compared between the two groups. The DH of fusion segment and lumbar lordosis(LL) were measured on anteroposterior and lateral lumbar spine and whole spine X-ray films before operation and at one week after operation to calculate correction values. The clinical efficacy was evaluated with Oswestry disability index(ODI) and visual analogue scale(VAS) of low back and leg pain before operation and at 3 and 6 months, and 1 year after operation. Univariate analysis and multi-factor logistic regression analysis were used to analyze and determine the risk factors of cage subsidence and influence of cage subsidence on clinical effects. Results: Univariate analysis showed that there were significant differences in age, osteoporosis, cage height, postoperative 1 week DH and surgically corrected DH between the two groups(P＜0.05). Logistic regression analysis showed age(OR=2.889, 95%CI: 1.807, 4.979) and osteoporosis(OR＝3.753, 95%CI: 1.926, 15.210), postoperative DH(OR＝2.777，95%CI: 1.155, 3.903) and intraoperative corrected DH(OR＝1.965, 95%CI: 1.523, 4.334) were the independent risk factors for cage subsidence after SA-OLIF surgery for LDD. There was no significant difference in VAS score and ODI between cage subsidence group and non-cage subsidence group before operation, and at 3 months, 6 months and one year after operation(P＞0.05). Conclusions: The older the age, the more serious the osteoporosis and the higher the corrected DH during operation can increase the risk of cage subsidence. Cage subsidence has no significant effect on the clinical effect within 1 year after SA-OLIF.