Use of Pro in Evaluating TAA and its Indications

CATEGORY: Ankle INTRODUCTION/PURPOSE: The indications for total ankle arthroplasty (TAA) have greatly expanded over the past decade. This rapid growth has been made possible with evidence-based medicine. Patient-reported outcomes (PROs) have been the primary outcome measure in many of these studies. To evaluate the quality of the evidence underlying expanded indications for TAA, we must first understand what PROs have been used in the evaluation of outcomes of TAA. METHODS: The goal of this study was to conduct a systematic review of the literature from 2010 to 2021 capturing all studies of TAA to determine what PRO instruments were used, and what facets of TAA practice were studied. Studies reporting on outcomes and PROs following a TAA procedure were selected to review from the PubMed database between January 2010 and July 2021. Results from one hundred sixty-three studies were reviewed and pooled for analysis for this study. RESULTS: After the evaluation of one hundred sixty-three studies, twenty-four separate PRO measures were identified in the literature. The PROs that were most reported in the literature from 2010 to 2021 were American Orthopedic Foot and Ankle Score (AOFAS) (49.1%), 36-Item Short Form Survey (SF-36) (40.5%), visual analog scale - pain (VAS) (35.6%), Ankle Osteoarthritis Scale (AOS) Questionnaire (17.8%), and Short Musculoskeletal Function Assessment (SMFA) (14.7%). The independent variables in these studies included a wide range of modifiable and unmodifiable patient factors such as age (27 studies), BMI (23 studies), smoking (8 studies), and preoperative coronal plane deformity (5 studies). A significant portion of the studies (41%) advocating for expanded indications did so based on the failure to find a difference in groups. CONCLUSION: The most commonly used PROs for TAA were AOFAS, SF-36, and VAS. The AOFAS score which had been the most commonly used PRO in 2009, is still today despite the determination in 2011 that it is not valid and there is a substantial risk for bias. Newer, validated PRO instruments, such as PROMIS, have not yet attained significant implementation in studies of TAA. The vast majority of the evidence supporting the expanded indications for TAA has come from studies with negative results. Caution should be exercised in interpreting these results and their study implications.