Sarcopenia Predicts Early Adjacent Segment Disease Development After Anterior and Oblique Lumbar Interbody Fusion

Operative Neurosurgery 29:667–677, 2025

his clinical study evaluates whether sarcopenia, measured by psoas-to-vertebral body morphometrics on preoperative MRI, predicts early adjacent segment disease (ASD) within three years after anterior or oblique lumbar interbody fusion (ALIF/OLIF). Retrospective analysis of 104 patients found sarcopenia strongly associated with ASD, with sarcopenic patients showing markedly higher ASD rates and greater muscle fat infiltration.

The paper reports that psoas area, P:VBR ratios, and age remained significant predictors on multivariate analysis, while spinopelvic parameters lost significance after adjustment. The authors propose routine preoperative morphometric screening to guide surgical planning, risk counseling, and targeted perioperative optimization for high-risk patients.

• Sarcopenia: Preoperative sarcopenia, defined by reduced psoas muscle area relative to vertebral body area, is a strong independent predictor of early adjacent segment disease (ASD) within 3 years after anterior or oblique lumbar interbody fusion (ALIF/OLIF) ().

• ASD Incidence: 24% of patients developed ASD within 3 years post-ALIF/OLIF; 84.21% of sarcopenic patients developed ASD compared to 10.59% of nonsarcopenic patients.

• Morphometric Assessment: Psoas:vertebral body ratio (P:VBR) at L4 on preoperative MRI provides a simple, objective screening tool for sarcopenia and ASD risk stratification.

• Spinopelvic Parameters: Postoperative pelvic tilt (PT) and pelvic incidence-lumbar lordosis (PI-LL) mismatch were associated with ASD in univariate analysis, but not after multivariate adjustment; sarcopenia remained the strongest predictor.

• Other Risk Factors: Older age, higher preoperative disability (ODI), more instrumented/interbody levels, and prior lumbar surgery also increased ASD risk, while gender, BMI, and comorbidities did not.

• Instrumentation vs. Stand-alone Cages: Patients with stand-alone ALIF/OLIF (no posterior instrumentation) had lower rates of ASD, possibly due to less mechanical stress on adjacent segments.

• Clinical Implications: Identifying sarcopenia preoperatively can inform surgical planning, patient counseling, and may guide targeted pre- and postoperative interventions to improve outcome.

• Future Directions: Further research is needed to determine if interventions like resistance training or dietary modification can reduce ASD risk in sarcopenic patients, and to establish standardized diagnostic criteria for sarcopenia in spine surgery.