Novel fat infiltration combined with muscle parameters for predicting postoperative complications following total knee arthroplasty: a retrospective study

To evaluate the predictive value of novel fat infiltration and muscle parameters for postoperative complications following total knee arthroplasty (TKA). Clinical data from 168 patients who underwent TKA between March 2022 and July 2024 were retrospectively reviewed. Patients were grouped based on the presence or absence of postoperative complications: those with complications were assigned to the complication group, and those without to the control group. Clinical demographic data and relevant laboratory indicators of the study subjects were collected through the hospital’s medical records system and compared. Logistic regression analysis was employed to identify risk factors associated with postoperative complications. A predictive model was constructed based on novel fat infiltration, muscle parameters, and hematologic indicators to evaluate their utility in assessing postoperative outcomes. Additionally, Pearson correlation analysis was used to investigate the associations between severe complications and the aforementioned parameters. A total of 168 TKA patients were included, with 136 patients (90.95%) in the control group and 32 patients (19.05%) in the complication group. Significant differences (P < 0.05) were observed between the two groups in Hospital for Special Surgery (HSS) scores, appendicular skeletal muscle mass, muscle fat infiltration, waist circumference (WC), muscle density, platelet-to-lymphocyte ratio (PLR), red blood cell count, and hemoglobin (HGB). Collinearity analysis revealed that none of the above indicators exhibited collinearity (VIF ≤ 10, tolerance ≥ 0.1), indicating that these indicators can be included in the Logistic regression model analysis. Pearson correlation analysis indicated associations between complications and appendicular skeletal muscle mass, muscle fat infiltration, WC, muscle density, PLR, red blood cell count, and hematocrit (HCT). Logistic regression confirmed these factors as significant contributors to postoperative complications. Receiver operating characteristic (ROC) curves demonstrated predictive value of these parameters for serious postoperative complications. Postoperative complications are common after TKA and are potentially influenced by factors such as appendicular skeletal muscle mass, muscle fat infiltration, WC, muscle density, PLR, red blood cell count, and HCT. These parameters may serve as valuable clinical tools for prognosis evaluation and provide a scientific basis for individualized treatment strategies.