SLR - November 2012 - Homan Badri
Reference: Queen R, De Biasio J, Butler R, DeOrio J, Easley M, Nunley J. Changes in Pain, Function, and Gait Mechanics Two Years Following Total Ankle Arthroplasty Performed with Two Modern Fixed Bearing Prostheses, Foot and Ankle International. 33(7): 535-54, 2012
Scientific Literature Review
Reviewed by: Homan Badri, DPM
Residency Program: Mount Auburn Hospital, Harvard Medical School, Cambridge, MA
Podiatric Relevance:
Unlike hip and knee total joint replacements, total ankle replacements have been associated with significant failures until newer generation implants were introduced over the past decade. Critical evaluation of ankle joint and gait mechanics continue to provide further insight into ideal design characteristics that are associated with improved function, pain reduction and implant survivorship. Despite the importance of gait mechanics, few studies include gait analysis as an outcome measure following total ankle replacement (TAR).
Methods:
This pre-post study identified 67 consecutive patients who received a fixed-bearing TAR within a single center’s database: INBONE or Salto Talaris. A total of 51/67 patients (mean age 65, mean BMI 28.7) met inclusion criteria where functional mechanics were evaluated preoperatively and then annually for a total of two years postoperatively. Secondary outcome measures assessed patient reported outcomes including VAS and AOFAS-hindfoot scores.
Results:
No significant differences were noted between the two implant groups. Almost all functional parameters improved at both the first and second year endpoints (p<0.05). There were no significant changes in the measured ankle dorsiflexion angle. The second year demonstrated a maintained ankle range of motion and overall improved kinematics. Both the VAS and AOFAS-hindfoot scores demonstrated statistically significant improvements at both endpoints (p<0.05).
Conclusion:
This short-term study found improvement in many gait parameters and clinical outcome measurements following fixed-bearing TARs. Study limitations include potential for bias regarding patient and implant selection, single-center study with only three surgeons and therefore reduced generalizability, multiple testing concerns, confounders were not addressed, use of a non-validated instrument (AOFAS-hindfoot) and missing data was not accounted for. Patients with complications following TAR were excluded from this study. Keeping these limitations in mind, this study provides additional information regarding the possible biomechanical and functional benefits of TAR under ideal conditions.