Effect of Postoperative Immobilization Time on PROMIS Scores and Clinical Outcomes in Ankle Fracture Patients
Authors: Carney Dwayne D. , Vyas Parth S. , Hicks Justin , Johnson Jeffrey E. , McCormick Jeremy J. , Klein Sandra E. , Backus Jonathon D. 
Published: January 2022

Category: Ankle; Trauma Introduction/Purpose: Ankle fractures are among the most common injuries that Orthopaedic Surgeons treat; yet, little guidance exists in postoperative protocols for ankle fractures concerning time of immobilization and weightbearing. Results from previous studies have been mixed; demonstrating improved outcomes, no difference in outcome, or poorer outcomes including increased wound complications in patients who are mobilized early. Here, we aim to investigate the association between early immobilization and patient reported outcomes. Our null hypothesis was that no difference in PROMIS scores would be identified in patients when comparing the effect of time of immobilization and time of weightbearing. Methods: A chart review identified ankle fractures that underwent surgical fixation between 2015 and 2020 at a level 1 trauma center and its associated facilities. One-hundred nineteen patients from 8 providers met inclusion criteria for our final analysis. Fifty patients were immobilized for <6 weeks and 69 patients were immobilized for at least 6 weeks. Our primary outcome measures included the PROMIS questionnaire, time of immobilization, and time to full weightbearing. Our secondary outcome measures included time to return to work, wound complications (infection, delayed healing), and complications associated with fracture fixation (loss of reduction, delayed union, reoperation, hardware failure). Repeated-measures ANOVAs were used to predict each of the PROMIS outcomes of anxiety, depression, physical function, and pain interference. Each model included the predictors of age, sex, race, BMI, payor, provider, time to radiographic union, time to return to work, time to full weightbearing, and early vs late immobilized groups. Results: There were no differences in PROMIS scores between mobilization groups and time to full weightbearing (p>0.05). Furthermore, there were no differences in wound complications nor complications associated with fracture fixation (p>0.05). Across our cohort, physical function scores were negatively impacted by higher BMI, increasing age and longer time to return to work/play (p<0.05). Our analysis further showed that depression, anxiety, pain interference and physical function levels improve as a function of time (p<0.05). African Americans showed more pain interference than other groups of patients (p<0.05). No difference in PROMIS scores were identified between treating providers (p>0.05). Conclusion: In this study, the null hypothesis was accepted. Data from our analysis shows no significant differences between the early and late mobilization and weightbearing groups in terms of PROMIS outcomes nor with wound complications and complications associated with fracture fixation. Our study does suggest that early mobilization after operative treatment of ankle fractures is safe and results in similar patient reported outcomes with no increased risk of complication. We did find that African American patients experienced more pain that other groups and we aim to further explore this topic to find potential modalities to address this disparity.