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Foot Ankle Surg. 2017 Jun;23(2):76-83. doi: 10.1016/j.fas.2016.02.007. Epub 2016 May 10.

Identifying the learning curve for total ankle replacement using a mobile bearing prosthesis.

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USPeC, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy. Electronic address:
USPeC, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.
Orthopaedic and Traumatology Division, Department of Medicine and Science of Aging, University G. d'Annunzio, Chieti-Pescara, Chieti, Italy.
Institute of Radiology, Seconda Università degli Studi di Napoli, Italy.
University of Southern California, Los Angeles, USA.



Total ankle arthroplasty remains a technically demanding surgery highly influenced by the operator experience. However, no consensus exists regarding the ideal number of cases that need to be performed before a surgeon is considered proficient. The aim of this study was to identify the learning curve of a specific replacement system with regards to intraoperative and postoperative outcomes.


The first 31 patients undergoing total ankle arthroplasty were examined. No additional procedures were performed at the time of the TAA. Intraoperative characteristics, postoperative complications, as well as clinical and radiologic outcomes were assessed with 24-month follow-up. Learning curves, examining the relationship between surgeon experience and patient outcomes, were determined using the Moving Average Method.


The operatory time, and the risk of intraoperative fractures decreased with increasing surgeon experience with the learning curve stabilizing after the 14th and 24th patient, respectively. Furthermore, there appeared to be a learning curve associated with most of the important clinical and radiological outcomes. The number of patients required to stabilize the learning curve for the VAS, ROM, and AOFAS was 11, 14 and 28, respectively. Radiographically, there appeared to be a learning curve of 22 patients required to stabilize the tibio-talar ratio. There was no learning curve associated with the SF-12 PCS and MCS as well as the α-, β-, and γ-angle.


This study demonstrates that a surgical learning curve does indeed exist when performing TAA. Most of the operative variables as well as clinical and radiological outcomes stabilize after a surgeon has performed 28 cases.


Ankle arthroplasty; Ankle replacement; HINTEGRA; Learning curve

[Indexed for MEDLINE]

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