Correlation of Radiographic Measurements With Patient-Centered Outcomes in Hallux Valgus Surgery

Abstract

Background: Evaluation of patients undergoing hallux valgus surgery has historically emphasized radiographic angles and relationships. However, patient-reported outcomes are increasingly important as health care systems trend towards a “value-based” delivery approach. Methods: We conducted a retrospective analysis of pre-existing data in our practice to examine whether patient-reported outcomes after bunion surgery, determined via Foot and Ankle Outcome Scores (FAOS), correlated with radiographic parameters commonly measured in hallux valgus deformity. Pearson correlation statistics and simple and multiple linear regression models were used to identify important radiographic predictors. There were 80 patients (80 feet) with mean follow-up of 59.3 ± 11.6 weeks (median 55, range 45.7-96.3 weeks) with complete data. Results: No radiographic measurement/variable achieved anything more than a weak correlation with any of the FAOS subscale scores at final follow-up; the study’s best was postoperative first-second intermetatarsal (IM) angle with sports and recreation scores ( r = −0.328, P = .005). There was no correlation found between change in hallux valgus angle, change in first-second IM angle, magnitude of preoperative hallux valgus angle or magnitude of preoperative first-second IM angle ( P > .05 for all). Furthermore, none of the study’s final multivariable models achieved an R2 > 0.24, and nearly all fell between 0.10 and 0.17. Conclusion: We conclude that radiographic angles were not well correlated with patient-centered outcomes in hallux valgus surgery. This study calls into question the current emphasis that is placed on x-ray values both pre- and postoperatively. Level of clinical evidence: Level III, comparative study.