Defining the Patient Acceptable Symptom State Using the Forgotten Joint Score 12 After Hip Arthroscopy

Purpose To contextualize the Forgotten Joint Score (FJS‐12) by identifying a patient acceptable symptomatic state (PASS) threshold for patients undergoing hip arthroscopy and to investigate factors which correlated with postoperative FJS‐12 score. Methods All patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) under the care of a single surgeon between January 2018 and November 2019 were prospectively identified and included. Exclusion criteria were Tönnis classification grade 2 or greater. Data (including FJS‐12, EuroQol‐5 Dimension‐5L [EQ‐5D‐5L], visual analog scale (VAS), and 12‐item International Hip Outcome Tool (iHOT‐12) scores) were available before surgery and at a minimum of 1 year after surgery. PASS was calculated using an anchor‐based approach and receiver operator characteristic curve analysis. Pearson correlation analysis was used to correlate preoperative and postoperative factors with postoperative FJS‐12 score. Results Seventy‐seven patients (54 female, 23 male; mean age 30.3 years [standard deviation {SD} 8.2]) were included. Linked longitudinal follow‐up data were available for 65 patients (84%) at a mean of 23.8 months (SD 6.4). Six patients required reoperation. Mean postoperative FJS‐12 score was 46.5 (SD 33.1) and mean change in score was 27.2 (SD 30.6, P < .001). The PASS threshold for the FJS‐12 was 38.5 (sensitivity 80%, specificity 88%), and the area under the curve was 0.852 (95% confidence interval 0.752‐0.951). Overall, 53.8% of patients achieved this score. Postoperative FJS‐12 score has moderate correlations with preoperative EQ‐5D‐5L, iHOT‐12, and FJS‐12 scores, and strong correlations with EQ‐5D‐5L, iHOT‐12 and VAS scores after surgery. Conclusions We report a postoperative PASS threshold of 38.5 points for the FJS‐12 after hip arthroscopy for FAI in a United Kingdom population. This value can act as a quantifiable target for clinicians using the FJS‐12 to monitor patient outcomes in practice. FJS‐12 has strong correlations with EQ‐5D‐5L, iHOT‐12, and VAS at a minimum 12 months after surgery. Clinical Relevance We have calculated the patient acceptable symptomatic state of the Forgotten Joint Score to be 38.5 points at short‐term follow‐up. This can assist clinicians in determining whether surgical interventions related to hip arthroscopy for FAI are meaningful to the patient.