Analysis of preoperative risk factors of adjacent segment disease after transforaminal lumbar interbody fusion

Currently, there is no information on the combined effect of body mass index (BMI), age, gender, main spinal-pelvic parameters and parameters of adjacent functional spinal unit (FSU) degeneration according to magnetic resonance imaging on development of adjacent segment degenerative disease (ASDd). Objective. To evaluate the effect of preoperative biometric and instrumental parameters of adjacent FSU on the risk of ASDd after transforaminal lumbar interbody fusion and determine personalized neurosurgical approach. Material and methods. We retrospectively studied patients after single-level transforaminal lumbar interbody fusion (group I, n=54), single-level transforaminal lumbar interbody fusion and interspinous stabilization of adjacent level (group II, n=55), preventive rigid fusion of adjacent segment (group III, n=56). Preoperative parameters and long-term clinical outcomes were assessed. Results. Paired correlation analysis established the main predictors of ASDd. Regression analysis determined absolute values of these predictors for each type of surgical intervention. Conclusion. Surgical intervention at the level of asymptomatic proximal adjacent segment is recommended as interspinous stabilization for moderate degenerative lesions, BMI <25 kg/m2, difference between pelvic index and lumbar lordosis 10.5—15°, segmental lordosis 6.5—10.5°. In case of severe degenerative lesions, BMI 25.1—31.1 kg/m2, significant deviations of spinal-pelvic parameters (segmental lordosis 5.5—10.5°, difference between pelvic index and lumbar lordosis 15.2—20°), preventive rigid stabilization is indicated.