Does Arthroplasty Really Protect the Hindfoot? A 13 year retrospective review of 516 cases for Further Hindfoot Procedures Following Ankle Arthrodesis vs Total Ankle Replacement

Category: Ankle Arthritis; Hindfoot Introduction/Purpose: Total Ankle Replacement (TAR) have a potential advantage of protecting further degradation of hindfoot joints by maintaining ankle joint motion. However, there is no study to our knowledge that directly compares hindfoot outcomes between TAR and Ankle Arthrodesis (AA) in the long term. Sokolowski et al. found that 68% of TAR patients had no radiological progression of subtalar arthritis after TAR, and 4% went on to fusion. Other studies have looked at 5 year outcomes finding higher hindfoot fusion rates post AA. However, no evaluation of the other hindfoot joints was made and no comparison made to other treatment. This study aimed to analyze the long-term rates of symptomatic hindfoot arthritis resulting in further procedures following TAR versus AA. Methods: We performed a retrospective review of all patients at our centre who had a TAR or AA since 2002. Case notes and imaging were reviewed and all instances of hindfoot treatment (injections or surgical procedures) noted. Patient were excluded who had no documentation, were followed up at other hospitals, had prior hindfoot fusion, or were having staged surgeries at the time of index treatment. Chi squared analysis was used to compare the cohorts. Results: Analysis revealed 428 eligible cases (275 TAR, 153 AA). TAR patients were older (mean age: 62 vs. 52 years, p=0.00001). Average follow up was 12.6 (1 – 21) years for TAR and 12.1 (1-21) years for AA. TAR showed lower rates of overall further hindfoot procedures compared to AA (14% vs. 24%, p=0.01), with significantly fewer hindfoot fusions (4% vs. 14%, p=0.0002). Revision rates were similar between groups (6% TAR vs. 4% AA, p=0.99). Conclusion: This study highlights higher rates of symptomatic hindfoot arthritis requiring intervention in AA compared to TAR. TAR appears to offer advantages in hindfoot preservation, with similar revision rates. Prospective studies integrating patient-reported outcomes are warranted to assess TAR versus AA efficacy on hindfoot function and overall well-being. Our findings advocate for TAR as the primary treatment for end-stage ankle arthritis, if appropriate, when considering symptomatic progression in management decisions.