A functional outcome study comparing total ankle arthroplasty (TAA) subjects with pain to subjects with absent level of pain by means of videofluoroscopy

Abstract Background Total ankle arthroplasty (TAA) subjects often suffer pain on the anteromedial side of their ankle joint. Whether this prevalent pain is caused by a changed motion pattern of the TAA is unclear. Therefore, this study assessed the kinematic differences in the motion of the TAA components during gait, comparing TAA subjects with elevated versus absent levels of pain. Methods Eleven TAA subjects (5 with pain vs. 6 without pain), all with unilateral Mobility™ TAA and at least two years post-operation, were recruited and stratified based on standard clinical assessed patient data. The 3D motion of the TAA was assessed by means of videofluoroscopy during level, uphill and downhill walking. Results The hypothesis that the pain group shows a different kinematic motion pattern than the no pain group could not be confirmed. Conclusions The same kinematic motion pattern causes pain in some patients, but not in others. Further investigation concerning ligament stresses is needed.