SLR - June 2021 - Andrew Robitaille

Functional Outcomes of Total Ankle Arthroplasty at a Mean Follow-up of 7.6 Years A Prospective, 3-Dimensional Gait Analysis

Reference: Brodsky, James, Scott, Daniel, MD, MBA, Ford, Samuel, Coleman, Scott, Daoud, Yahya. Functional Outcomes of Total Ankle Arthroplasty at a Mean Follow-up of 7.6 Years: A Prospective, 3-Dimensional Gait Analysis. J Bone Joint Surg Am. 2021;103(6):477-482. doi:10.2106/JBJS.20.00659

Level of Evidence: Level IV

Scientific Literature Review 

Reviewed By: Andrew Robitaille, DPM
Residency Program: Beaumont Hospital Wayne - Wayne, MI

Podiatric Relevance: Ankle arthrodesis has been considered the gold-standard treatment because it offers reliable, long-standing improvement in pain and function. Ankle arthrodesis is associated with loss of ankle motion, increased risk of adjacent joint arthritis, nonunion, and gait limitations. Multiple studies have shown objective improvements in gait following total ankle arthroplasty when compared with ankle arthrodesis, but it is still unclear whether these improvements persist or change at medium and long-term follow-up. The authors hypothesized that patients who underwent TAA for end-stage ankle arthritis would show significant improvements in temporospatial and kinetic function at a minimum follow-up of 5 years, compared with preoperative function.

Methods: Patients were retrospectively identified who underwent TAA at a tertiary center by a single foot-and-ankle surgeon between 1999 and 2008. All patients were included who underwent unilateral primary TAA as well as preoperative and five-year postoperative three-dimensional gait analysis. Patients were excluded who were unable to complete either the preoperative or postoperative gait analysis or who had a prior or concomitant hindfoot arthrodesis, if the TAA was a revision. Postoperative function was compared with preoperative for each of the 33 patients who met the inclusion criteria. Of the 33 patients, 28 underwent TAA with the Scandinavian Total Ankle Replacement (STAR; Stryker) and five, with the Salto Talaris Ankle (Integra LifeSciences).

Results: Thirty-three patients underwent primary TAA, with gait analysis performed preoperatively and at a minimum follow-up of five years (mean, 7.6 years; range, five to 13.3 years). The mean age at the time of the surgical procedure was 61 years (range, 37 to 79 years). The group included 25 female and 8 male patients, and the mean BMI was 28 kg/m2 (range, 19.3 to 40.7 kg/m2). Significant improvements were observed in multiple gait parameters, with increases in cadence (+9.5 steps/min), step length (+4.4 centimeters), and walking speed (+0.2 m/s), and increases in total sagittal range of motion (+2.0 degrees), plantar flexion at initial contact (+2.7 degrees), and maximum plantar flexion (+2.0 degrees). There was increased plantar flexion at toe-off, but the difference was not significant. BMI and the number of years since TAA had no significant effect. Sex and age at the time of surgery had small, but significant effects on multiple gait parameters. Female patients had a smaller step length both preoperatively and postoperatively. Older age correlated with shorter preoperative and postoperative step length.

Conclusions: The study reports two main benefits of TAA, preservation of range of motion at the ankle joint and reduction of overloading of the adjacent hindfoot joints. The increasing utilization of TAA has shown consistent improvement in functional outcomes. The authors aim was to use gait analysis to objectively quantify how much improvement is seen following TAA. This study showed improvements in objective parameters of gait following TAA that persisted at a mean follow-up of seven years. This study expands our understanding of the history of TAA, showing that many of the previously reported early and medium-term improvements in gait following TAA persist over a longer-term follow-up.

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