SLR - June 2021 - Joshua Carroll

Application of a Customized Total Talar Prosthesis for Revision Total Ankle Arthroplasty 

Reference: Morita S, Taniguchi A, Miyamoto T, Kurokawa H, Tanaka Y. Application of a Customized Total Talar Prosthesis for Revision Total Ankle Arthroplasty. JB JS Open Access. 2020 Oct 28;5(4)

Level of Evidence: IV

Scientific Literature Review

Reviewed By: Joshua Carroll, DPM
Residency Program: Beaumont Wayne, Wayne, MI

Podiatric Relevance: Total ankle arthroplasty (TAA) is a staple procedure in the treatment of end stage osteoarthritis especially in the middle aged to older population. Due to subsidence issues with the tibial component, tibiotalocalcaneal fusion is often performed as a salvage procedure, however, this requires a large graft an decreased functionality. In order to circumvent these issues an approach is required that does not compromise ankle function. The authors hypothesized that use of a total talar prosthesis in combination with the tibial component used in a total ankle arthroplasty would be an effective strategy for treating subsidence of the talar component after a TAA.

Methods: A case series including 10 patients, all female, was performed with 4 of the patients receiving replacement of the talar portion of the TAA and 6 receiving replacement of both the tibial and talar components. For the production of the artificial talus, CT was performed on the contralateral normal talus. Mean age of patients was 67 and mean follow up was 49 months. Outcome measures assessed included pain, function, alignment, range of motion, osteophyte formation, and degeneration at the subtalar joint and the talonavicular joint using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot score. 

Results: In the outcome measures of pain, range of motion and function, improvement was statistically significant. Alignment remained the same pre and post operatively. In terms of osteophyte formation results were unchanged pre and post operatively. In terms of degeneration at the involved joints results revealed the progression of degenerative changes in the talonavicular joint. In terms of post-operative complications, one patient had gastroparesis. No other complications were observed. 

Conclusions: The authors concluded that revision TAA using the described method can lead to improved clinical outcomes with pain relief and improved ankle range of motion. The results of this study are promising albeit the small sample size. The issue of subsidence of the talar component cannot be ignored with a TAA, however, it is not clear if this issue is resolved with the use of a total talus as the total talus has been shown to subside as well. Further studies would need to be performed with larger sample sizes to validate these results. 

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