Risk factors of adjacent segment diseases after lumbar fusion / 中华骨科杂志

ABSTRACT

Objective:To explore the risk factors of adjacent segment diseases (ASDis) after lumbar fusion, summarize the prevention strategies and provide reference for clinical treatment.Methods:All of 258 patients who underwent lumbar interbody fusion from March 2014 to March 2019 were retrospectively analyzed, including 95 males and 163 females, the age of whom was 61.8±8.4 years (range, 39-77 years). The patients were divided into ASDis group and non-ASDis group according to whether ASDis occurred at the follow-up of 24 months after operation. The patient's individual factors [gender, age, body mass index (BMI), main diagnosis, preoperative paraspinal muscle fatty degree, etc.] and surgical factors (operation type, fixed segment, fusion segment, etc.), sagittal parameters [lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL] were recorded. After univariate analysis of potential risk factors, the factors with P<0.05 were substituted into logistic regression model for multivariate analysis to determine the risk factors of ASDis after lumbar fusion. Results:ASDis occurred in 24 patients after lumbar fusion, with an incidence of 9.3% (24/258); univariate analysis showed that age ≥ 60 years old, complicated with osteoporosis, preoperative fatty degree of paraspinal muscle (GCS grade≥3), PLIF operation, suspension fixation, total laminectomy and multi-segment fusion (≥ 3 segments) were the potential risk factors for ASDis after operation (P<0.05); Gender, education level, partner status, type of work, BMI, obesity (BMI≥24 kg/m 2) , smoking, use of bisphosphonates, concomitant lumbar spinal stenosis, lumbar lordosis angle, pelvic incidence angle, pelvic tilt angle, sacral slope angle, and PI-LL had no significant correlation with ASDis. Logistic regression analysis showed that age ≥ 60 years ( OR=5.63, 95% CI 1.56, 20.29, P=0.008), preoperative paravertebral muscle fatty GCS ≥ 3 ( OR=4.82, 95% CI 1.36, 17.13, P=0.015), combined with osteoporosis ( OR=14.04, 95% CI 2.53, 77.79, P=0.002), PLIF ( OR=9.69, 95% CI 1.91, 49.03, P=0.001), and multi-segment fixation ( OR=9.36, 95% CI 1.77, 49.41, P=0.008) were the risk factors for ASDis after lumbar fusion; Incomplete laminectomy ( OR=0.09, 95% CI 0.02, 0.37, P=0.001) and suspension fixation ( OR=0.16, 95% CI 0.02, 0.94, P=0.042) were the protective factors of ASDis after lumbar fusion. Conclusion:The patients with age ≥ 60 years old, osteoporosis and preoperative paraspinal muscle fatty degree ≥ 3 grade GCS should be more careful in choosing the surgical methods, and try to choose transforaminal interbody fusion, posterolateral fusion, short segment fusion, decompression with preservation of vertebral lamina, suspension fixation and other surgical methods to reduce the incidence of postoperative ASDis.