Are Sicker Patients Less Likely to Improve after Ankle Fusion?

Abstract

Category: Ankle Arthritis Introduction/Purpose: The influence of pre-existing medical conditions on post-operative patient reported outcomes are important to consider when selecting and preparing a patient for surgery. The purpose of this study was to determine the impact of medical comorbidities on post-operative physical function and pain in patients undergoing ankle arthrodesis. Methods: This was a Global IRB approved retrospective review of 88 consecutive ankle arthrodesis procedures performed from May 2015 to March 2018. Patient reported physical function (PF) and pain interference (PI) were measured as part of the routine care via the PROMIS PF and PI computerized adaptive test. A chart review was performed to determine the Charlson Comorbidities Index (CCI), ASA scores, and demographic data. A multivariate analysis predicting pre- and post-operative PROMIS PF based on PI, ASA score, and CCI was performed. Spearman correlations for CCI, ASA, pre- and post-operative PROMIS T- scores for PF and PI were calculated. Results: The ASA score and CCI were not associated with pre-operative PI, although the CCI was predictive of pre-operative physical function (p=0.06), indicating that patients with a higher CCI had lower pre-operative PF. Pre-operative PF and ASA were the best individual predictors of physical function at 6 months post-operatively (r=0.51). At 6 months after undergoing ankle arthrodesis, there was no correlation between CCI and post-operative PROMIS PF and PI outcome T-scores (r=0.02, r=-0.06, respectively), this continued at 1 year post-operatively (r=-0.17, r=0.04, respectively). Demographic data, ASA, CCI, and mean PROMIS T-scores are included in Table 1. Conclusion: Sicker patients (ASA score=3) and those with lower pre-operative function recovered more slowly as indicated by lower physical function at 6 months and obtained less physical function benefit from ankle fusion than healthier patients at one year. The results of this study can assist surgeons with risk stratification and educating patients about surgical expectations as pre- operative physical function and ASA score appear to influence post-operative physical function after undergoing ankle arthrodesis.