A prospective cohort study develops and validates a machine learning model for predicting ecchymosis after total knee
Xuefeng Luo1,2, Wei Bao1,3, Yu Ye4
1Department of Orthopaedic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Scientific Reports
|January 3, 2026
Summary
Predicting ecchymosis after total knee arthroplasty (TKA) is now possible. Machine learning models identify key risk factors like low prealbumin and high fibrinogen degradation products to guide personalized blood management.
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Data Science in Medicine
Background:
- Total knee arthroplasty (TKA) is a common surgery for advanced knee disease.
- Perioperative bleeding and ecchymosis are significant complications after TKA.
- Accurate prediction of ecchymosis can improve patient outcomes and reduce healthcare costs.
Purpose of the Study:
- To develop and validate a machine learning model for predicting ecchymosis after TKA.
- To identify key clinical and laboratory risk factors associated with TKA-related ecchymosis.
- To enable personalized perioperative blood management strategies.
Main Methods:
- Prospective study of 416 TKA patients, with data split for training (312) and validation (104).
- Feature selection using LASSO, RF-RFE, and BORUTA to identify risk factors.
- Machine learning models including RF, XGBoost, SVM, and LGBM were employed for prediction.
- Key predictors identified: low prealbumin, reduced coagulation index (CI) and its change (XCI), high fibrinogen degradation products (FDP), and postoperative day 1 total blood loss (TBL).
Main Results:
- The developed prediction model demonstrated high performance.
- Area under the curve (AUC) values were 0.927 for the training set and 0.954 for the validation set.
- Significant risk factors identified include prealbumin, CI, XCI, FDP, and postoperative TBL.
Conclusions:
- A robust machine learning model accurately predicts ecchymosis in TKA patients.
- The model facilitates early and precise risk assessment.
- Findings support personalized anticoagulation therapy and optimized perioperative blood management in TKA.

