Increased Early Revision Rate With the INFINITY Total Ankle Prosthesis

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Medical Device Technology

Background:

• New 2-component total ankle arthroplasty (TAA) systems with minimal bone resection are emerging.
• Limited clinical outcome data is available for these novel prostheses.
• The INFINITY prosthesis is one such 2-component system.

Purpose of the Study:

• To evaluate the early revision rate in patients who received the INFINITY total ankle arthroplasty.
• To identify the primary reasons for early revision surgery in this cohort.
• To assess the incidence of peri-implant lucency as an indicator of loosening.

Main Methods:

• A retrospective review of patients who underwent primary TAA with the INFINITY prosthesis was conducted.
• Inclusion criteria required patients to be at least 1 year postoperative.
• Revision surgery and radiographic lucency were the primary and secondary outcomes, respectively.

Main Results:

• 10% of patients (16 ankles) required revision surgery at a mean of 13 months postoperatively.
• The most frequent causes for revision were tibial component loosening and deep infection (3.8% each).
• Radiographic follow-up revealed tibial component loosening in 7.4% of ankles with retained components.

Conclusions:

• The INFINITY prosthesis demonstrated an elevated early revision rate compared to other TAA systems.
• Tibial component loosening is a significant concern requiring further investigation.
• These findings highlight potential challenges with this specific 2-component ankle implant.