SLR - February 2018 - Gregory A. Foote

Comparison of Treatment Outcomes of Arthrodesis and Two Generations of Ankle Replacement Implants

Reference: Benich MR, Ledoux WR, Orendurff MS, Shofer JB, Hansen ST, Davitt J, Anderson JG, Bohay D, Coetzee JC, Maskill J, Brage M, Houghton M, Sangeorzan BJ. Comparison of Treatment Outcomes of Arthrodesis and Two Generations of Ankle Replacement Implants. J Bone Joint Surg Am. 2017 Nov 1;99(21):1792–1800.

Scientific Literature Review

Reviewed By: Gregory A. Foote, DPM
Residency Program: UF Health Jacksonville, Jacksonville, FL

Podiatric Relevance: Total ankle replacements (TARs) have historically reported success rates inferior to those seen with ankle arthrodesis. Recently, there has been a shift in this trend as new generations of ankle implants have shown superior outcomes to primary fusion. The authors of this study prospectively investigated two generations of ankle replacement implants versus ankle arthrodesis and hypothesized a greater improvement in self-reported outcomes within the TAR group.

Methods: The study prospectively examined 273 consecutive arthritic ankles between 2005 treated with either arthrodesis (103) or TAR (170). All implants used were FDA-approved, including the Agility (DePuy; 58), Salto Talaris (Tornier; 103) and INBONE/INBONE II (Wright Medical; nine). All surgeons had a minimum of five years of experience after a five-year residency, had performed a minimum of 100 arthroplasties and had performed at least 30 ankle arthrodesis and 30 TARs before the trial began. Patients completed a pain score, a Musculoskeletal Function Assessment (MFA) and a Short Form-36 (SF-36) survey preoperatively and six-, 12-, 24- and 36-month follow-up either through an interview or by mail. Pain score was based on a valid and responsive numerical scale of 0 to 10, the MFA has been validated in a population of younger patients with posttraumatic arthritis, and the SF-36 is a 36-item survey with eight domains, four for the assessment of physical health and four to assess mental health.

Results: Significant mean improvement was appreciated in all outcomes except for the SF-36 General Health after both types of surgery, with the greatest improvement seen during the first six months postoperatively. The average improvement over the three-year period was significantly better in the TAR group than in the arthrodesis group for the MFA scores and the SF-36 Physical Functioning scores. Better outcomes after TAR were achieved in patients who had received the newer-generation device (Salto Talaris implant) compared to arthrodesis. Age and BMI-adjusted mean difference in preoperative scores indicated worse preoperative function in the patients treated with the newer-generation device than in those in the arthrodesis group. Greater postoperative improvement in MFA scores were also seen in younger patients.

Conclusion: The authors came to the conclusion that both the TAR and ankle arthrodesis are effective treatments for end-stage ankle arthritis. When performed by experienced surgeons, TAR offered an advantageous relief of pain and functional outcome at three-year follow-up. Comparing newer-generation implants with arthrodesis, the benefit of TAR was found to be slightly stronger. This study sheds light on the continued success of TAR in regards to the newer-generation implants on the market. These results indicate the need for a progression in the use of ankle implants as an alternative to primary fusion. An ankle arthrodesis always remains a viable option for ankle arthritis, but for the ideal patient, an initial attempt at TAR may need to be considered to achieve the most optimal postoperative outcome. 

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