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Artificial Intelligence-Driven Decision-Making for Knee Joint Manipulation Following Primary Total Knee Arthroplasty
Stefano Ghirardelli1, Kai Chun Augustine Chan2, Pieralberto Valpiana3
1Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York; Paracelsus Medical University, Institute of Biomechanics, Salzburg, Austria.
The Journal of Arthroplasty
|December 17, 2025
Summary
Artificial intelligence (AI) can guide manipulation under anesthesia (MUA) timing for total knee arthroplasty (TKA) stiffness. AI suggests MUA at six weeks for specific knee stiffness, improving range of motion (ROM).
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Artificial Intelligence in Medicine
Background:
- Postoperative stiffness is a common complication following total knee arthroplasty (TKA).
- Manipulation under anesthesia (MUA) is frequently used to treat TKA stiffness.
- Optimal MUA timing, motion thresholds, and expected outcomes are not well-defined due to limited evidence.
Purpose of the Study:
- To evaluate an artificial intelligence (AI) platform's ability to create a data-driven decision framework for MUA after primary TKA.
- To define appropriate MUA timing and predict range of motion (ROM) gains using AI modeling.
Main Methods:
- A systematic literature review was conducted on ROM trajectory and manipulation following primary TKA.
- Data from the literature review were used to train an AI model.
- AI scenarios modeled variables like time from surgery, knee flexion, extension deficit, preoperative ROM, and BMI to determine MUA appropriateness and expected ROM improvements.
Main Results:
- AI model indicates MUA is appropriate for patients with knee flexion < 80 degrees and/or extension deficits > 20 degrees at six weeks post-TKA.
- Predicted mean ROM gains with MUA are 26 degrees in flexion and 3 degrees in extension.
- Delaying MUA beyond 90 days reduced expected flexion gains; combining MUA with arthroscopic lysis of adhesions is advised for persistent stiffness beyond three months.
Conclusions:
- An AI-generated decision framework for MUA aligns with current consensus on timing and patient selection.
- The AI tool should supplement, not replace, clinical judgment due to evidence limitations and the complexity of postoperative stiffness.

