Correlative factors of low back pain after single-level oblique lateral interbody fusion / 中华骨科杂志

ABSTRACT

Objective:The study retrospectively identified the correlative factors of low back pain after single-level oblique lateral interbody fusion (OLIF).Methods:Records of 93 patients (55 males and 38 females) who underwent OLIF (oblique lateral interbody fusion) surgery for lumbar degenerative diseases from May 2016 to September 2019 were analyzed retrospectively and patients' age was 55.73±9.48 years (range 32-78 years). There were 18 patients underwent L 3, 4 segment (19.35%), 73 patients underwent L 4, 5 segment (78.50%), and 2 patients underwent L 5S 1 segment (2.15%). There were 43 patients underwent OLIF stand alone and 50 patients underwent OLIF combined with lateral or posterior internal fixation. The follow-up time was 22.86±5.90 months (range 12-32 months). According to whether the visual analog scale (VAS)≥3 at the last follow-up visit, the patients were divided into low back pain group and no low back pain group. The demographic characteristics (age, gender, body mass index and comorbidities), basic surgical data (surgical segments, surgical methods, surgical time, intraoperative bleeding, endplate injury or not during operation), imaging data (lumbar lordosis, segmental lordosis, intervertebral height and cage subside) and lumbar function were recorded. The potential related factors were analyzed by univariate analysis, and the factors with P<0.05 were selected in the multivariate logistic regression model. Then the risk factors of low back pain after OLIF were determined by multivariate logistic regression analysis. Results:Nineteen patients with VAS score equal or greater than 3 were included in low back pain group, and the remaining 74 patients were included in no low back pain group. There was no significant difference in baseline data such as age, gender, BMI, follow-up time and comorbidities between two groups. There was no significant difference in VAS score between the two groups before operation ( t=0.818, P=0.414), but there was significant difference in VAS score at last follow-up visit ( t=6.958, P<0.001). The incidence rate of osteoporosis in low back pain group (63.16%) was significantly higher than that in no low back pain group (25.68%) ( t=9.558, P=0.002). There was no significant difference in vertebral height between the two groups ( t=1.008, P=0.316), however, the vertebral height was higher in no low back pain group ( t=2.537, P=0.316) at the last follow-up. The incidence of cage subsidencewas 8.11% in no low back pain group and 36.84% in low back pain group and there was significant difference between the two groups ( t=10.381, P=0.001). Multivariate logistic regression analysis showed that osteoporosis ( P=0.009), intraoperative bone endplate injury ( P=0.031), decreased intervertebral space height ( P=0.029) and cage subsidence ( P=0.016) were associated with low back pain after single-level OLIF. Conclusion:Low back pain is one of the common complications after OLIF. Osteoporosis, intraoperative bony endplate injury, decreased intervertebral space height and cage subsidence were closely related to postoperative low back pain. In order to reduce the incidence of postoperative low back pain and improve the clinical outcomes, attention should be paid to the protection of the bony endplate, rational use of internal fixation and active anti-osteoporosis treatment after operation.