Paper 24: The Natural Course of Recovery for Health-Related Quality of Life Following Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

Objectives: To determine if subgroups of patients exist based on the recovery trajectory of health-related quality of life following hip arthroscopy for femoroacetabular impingement syndrome (FAIS), and to determine clinical data predictors for these subgroups of patients. Methods: A clinical hip data repository was queried for patients who underwent primary hip arthroscopy for the treatment of FAIS between January 2012 and May 2018. Patients who completed pre-operative, 1-year, and 2-year International Hip Outcome Tool-12 (iHOT-12) were included in the study. Latent class growth analysis (LCGA) and growth mixture models (GMM) were used to identify subgroups of patients based on trajectories of recovery for iHOT-12 utilizing 3 clinical time points (pre-operative [within 1 week of surgery], one-year postoperative, and two-year postoperative). LCGA and GMM models using 1 – 6 classes were assessed for best model fit according to AIC, BIC, bootstrapped likelihood ratio test, and log-likelihood ratios. Following the final model selection, a multivariable multinomial logistic regression on the final model was performed with the largest class as the reference group to determine clinical predictors of subgroup membership. Results: A total of 443 patients with an average age of 34.25 ± 12.65 and BMI of 25.02 ± 5.11met inclusion criteria. The 3-class GMM was the best fit model, and the resulting subgroups were named based on trajectories of iHOT-12 scores: early progressors, late regressors, and late progressors (Figure 1A). The early progressors comprised 70.0% of the study group and had substantial early improvement between preoperative and 1-year follow-up with further improved 2-year outcomes (Figure 1B). The late regressors comprised 22.3% of the study sample and demonstrated improvement between preoperative and 1-year follow-up with decreasing function between 1-year and 2-years postoperatively (Figure 1C). The late progressors represented the smallest group at 7.7% and only demonstrated improved outcomes after 1-year postoperatively (Figure 1D). Predictors of the late regressor membership were worker's compensation status, psychiatric history, preoperative chronic pain, and lower preoperative iHOT-12 scores. Patients in the late progressor subgroup were less likely to participate in physical hobbies/exercise. Conclusions: Using growth mixture models, three natural courses of health-related quality of life recovery following hip arthroscopy for the treatment of FAIS were identified: early progressors, late regressors, and late progressors. Worker's compensation status, psychiatric history, preoperative chronic pain, and lower preoperative iHOT-12 scores were predictive of less than favorable trajectories of recovery. Figure 1. [ABSTRACT FROM AUTHOR]