Rotating-hinge total knee for revision total knee arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Arthroplasty

Background:

• Revision total knee arthroplasty (TKA) is complex, often necessitated by severe instability and bone loss.
• Rotating-hinge knee implants are designed to address these challenges in revision TKA.

Purpose of the Study:

• To evaluate the mid-term outcomes of NexGen Rotating Hinge Knees in revision TKA.
• To assess implant survival rates and identify factors influencing complications.

Main Methods:

• A retrospective review of 31 NexGen Rotating Hinge Knees implanted in 29 patients.
• Pre- and post-operative assessment using the Hospital for Special Surgery (HSS) Knee Score and range of motion.
• Radiographic evaluation and survival analysis over an average follow-up of 60.3 months.

Main Results:

• Significant improvement in HSS Knee Score (65.5 to 88.4) and range of motion (90.9° to 114.4°).
• No implant ruptures or fractures; radiolucent lines noted in 20/26 patients, progressive in 2.
• 10 patients experienced complications; aseptic loosening was the primary indication for revision.

Conclusions:

• Rotating-hinge knee implants provide acceptable mid-term outcomes for revision TKA with ligamentous instability.
• Implant rigidity may increase stress transfer, but early loosening is more associated with short tibial stems.
• High failure rates are often attributed to patient complexity and surgical challenges, not solely the hinged mechanism.