Rotating Hinge Distal Femur Replacement: A Turn for the Worse

Area of Science:

• Orthopedic Surgery
• Infectious Diseases
• Biomedical Engineering

Background:

• Periprosthetic joint infection (PJI) is a significant complication following arthroplasty.
• Press-fit femoral components are commonly used in modern joint replacement surgery.
• Understanding potential failure modes of implants is critical for patient safety.

Observation:

• A rare case of 180° rotation of a press-fit femoral component occurred postoperatively.
• This complication was associated with a preoperative periprosthetic joint infection.
• The rotational instability presented a unique challenge in revision arthroplasty.

Findings:

• Preoperative infection can compromise the fixation of press-fit femoral components.
• Significant rotational malalignment of the femoral component can occur as a direct consequence of infection.
• This complication highlights the biomechanical vulnerability of press-fit designs in infected joints.

Implications:

• Arthroplasty surgeons must be aware of the potential for femoral component rotation in infected cases.
• Early recognition and management are essential to prevent further complications.
• This case underscores the importance of robust implant fixation strategies, especially in the presence of infection.