This study aimed to longitudinally examine whether preoperative trunk muscle mass is a predictive factor for achieving a Patient Acceptable Symptom State (PASS) on the postoperative Oswestry Disability Index (ODI), a measure of ADL limitations due to low back pain, among spinal surgery patients.
This retrospective cohort study included individuals aged 55 years or older who underwent surgery for degenerative spinal disease. The exclusion criteria were as follows: having undergone surgery for bone tumors, infection, or trauma; having undergone revision surgery; a history of orthopedic disease or surgery of the bones or joints; inability to walk; presence of pacemaker; difficulty answering the questionnaire; and deviations from the clinical path defined by our hospital. The survey items included postoperative ODI, preoperative trunk muscle mass, age, sex, body mass index, Charlson Comorbidity Index, preoperative ODI, and number of fixed intervertebral segments. PASS achievement was defined as a postoperative ODI score of 22%. Trunk muscle mass was calculated by BIA using an InBody S10 Body Water Analyzer (InBody Japan Co., Ltd.). Statistical analyses were performed using univariate and adjusted multivariate models to investigate whether preoperative trunk muscle mass was an independent predictor of PASS achievement (p 0.05). All analyses were performed separately for men and women.
A total of 129 men (mean age, 69.9 ± 8.7 years) and 190 women (73.7 ± 7.3 years) were included. Preoperative trunk muscle mass was a predictor of PASS on the univariate (men: odds ratio [95% confidence interval], 1.8 [1.1–3.1], p = 0.02; women: 1.8 [1.0–3.0], p = 0.02) and adjusted multivariate (men: 2.9 [1.2–6.9], p = 0.01; women: 2.5 [1.0–6.3], p = 0.04) models.
Our results suggest that the preoperative trunk muscle mass of spinal surgery patients can predict whether they will achieve PASS on the postoperative ODI.
Patients with reduced preoperative trunk muscle mass who undergo spinal surgery may not show satisfactory postoperative improvement. Preoperative trunk muscle mass may be useful for preventing lower back pain during the early postoperative period. However, as few studies have calculated trunk muscle mass using BIA, further research is required to validate these results.
Trunk muscle mass
Spinal surgery
