Do Interval PROMIS Scores Correlate with Interval MCID Achievement following Surgery for Lateral Ankle Instability?

Submission Type: Ankle Instability Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Of the various surgical techniques available for Chronic Ankle Instability (CAI), the Brostrom-Gould (BG) procedure is the gold standard. This study aims to assess interval changes in patient reported outcomes following BG surgery and to identify at which time points, patients achieve a minimal clinically important difference (MCID). Secondary objectives include determining if there are any sociodemographic factors that impact a patient's likelihood of achieving MCID following BG repair. To our knowledge, this study is the first to assess interval changes with the inclusion of preoperative PROMIS score data to allow for a more comprehensive understanding of postoperative changes in overall well-being, pain, and physical function after surgery for lateral ankle instability. Methods: A retrospective review of 78 patients undergoing a BG procedure at a single institution by two fellowship-trained foot and ankle surgeons between July 2022 and February 2024. Patients were identified via CPT codes and an extensive review of the surgical scheduling record. Inclusion criteria were restricted to patients age >16, a diagnosis of CAI undergoing a BG procedure (primary or revision) with completed preoperative PROMIS assessments. Prospectively collected PROMIS scores, including PROMIS Global 10 Mental Health (MH), Physical Function (PF), and Pain Interference (PI) were collected preoperatively and at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year postoperatively. Patient sociodemographic data and past medical history was collected via chart review. MCIDs were calculated according to a distribution-based method. Descriptive and inferential statistics were performed. Univariate linear regression analysis was performed to determine associations between patient demographics and the achievement of MCID. Results: Among the 43 patients included, 76.7% were female. Mean age at time of surgery was 39.6 [range 16-72 years]. Mean preoperative BMI was 32.8 [8.96]. Mean preoperative MH was 51.3 [8.9], PF was 40.2 [6.9], and PI was 61.6 [6.8]. Changes in mean PROMIS scores relative to baseline were seen in PROMIS PF (p < 0.0001), PI (p=0.0003), and MH (p= 0.8832). The greatest improvement in PF and PI occurred between 6 weeks and 3 months. Throughout 1 year follow up, 25.0% of patients achieved MCID in Global PROMIS MH, 51.28% achieved MCID in PROMIS PF, and 13.16% achieved MCID in PROMIS PI. With our confidence level, there were no statistically significant associations between the odds of achieving MCID and patient sociodemographic or past medical history. Conclusion: Although average PROMIS PF and PI significantly improved following BG surgery, preoperative PROMIS scores may not be the best determinant of post-operative achievement of MCID based on the results seen among our patient cohort. However, as one of the first studies to assess changes in interval PROMIS scores with the inclusion of achievement of MCID at each interval, this study contributes valuable insight to provide patients and providers with an appropriate frame of reference for expectations at several intervals following BG surgery.