Revision arthroplasty with rotating hinge systems for total knee arthroplasty instability

Area of Science:

• Orthopaedic surgery
• Biomedical engineering
• Reconstructive surgery

Background:

• Total knee arthroplasty (TKA) can result in ligament instability and osseous defects.
• Revision TKA is complex, often requiring specialized implant systems.
• Existing TKA may fail due to instability or bone loss, necessitating revision surgery.

Purpose of the Study:

• To evaluate the efficacy of a cemented rotating hinge system for TKA revision.
• To restore stability and improve joint function in patients with complex knee instability post-TKA.
• To assess functional outcomes and pain reduction following revision with this specific implant system.

Main Methods:

• Prospective study of 18 patients undergoing TKA revision with a cemented rotating hinge system.
• Included patients with ligament insufficiency and/or Anderson Orthopaedic Research Institute (AORI) type II defects.
• Surgical technique involved component removal, debridement, joint line reconstruction, and cement fixation.

Main Results:

• Significant improvement in Oxford Knee Score (OKS) from 19 to 29 (p=0.004).
• Significant improvement in Knee Society Score (KSS) knee assessment from 35 to 67 (p=0.002).
• Significant reduction in pain scores from 7 to 24 (p=0.008) at a mean 37-month follow-up.

Conclusions:

• The cemented rotating hinge system provides a viable solution for TKA revision in cases of ligament instability.
• This system significantly enhances functional outcomes, including range of motion and pain relief.
• The study supports the use of this specialized implant for complex TKA revisions.