Background: Hip arthroscopy has become an important tool for surgical treatment of intra-articular hip pathology. Predictive models for clinically meaningful outcomes in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS) are unknown. Purpose: To apply a machine learning model to determine preoperative variables predictive for achieving the minimal clinically important difference (MCID) at 2 years after hip arthroscopy for FAIS. Study Design: Case-control study; Level of evidence, 3. Methods: Data were analyzed for patients who underwent hip arthroscopy for FAIS by a high-volume fellowship-trained surgeon between January 2012 and July 2016. The MCID cutoffs for the Hip Outcome Score–Activities of Daily Living (HOS-ADL), HOS–Sport Specific (HOS-SS), and modified Harris Hip Score (mHHS) were 9.8, 14.4, and 9.14, respectively. Predictive models for achieving the MCID with respect to each were built with the LASSO algorithm (least absolute shrinkage and selection operator) for feature selection, followed by logistic regression on the selected features. Study data were analyzed with PatientIQ, a cloud-based research and analytics platform for health care. Results: Of 1103 patients who met inclusion criteria, 898 (81.4%) had a minimum of 2-year reported outcomes and were entered into the modeling algorithm. A total of 74.0%, 73.5%, and 79.9% met the HOS-ADL, HOS-SS, and mHHS threshold scores for achieving the MCID. Predictors of not achieving the HOS-ADL MCID included anxiety/depression, symptom duration for >2 years before surgery, higher body mass index, high preoperative HOS-ADL score, and preoperative hip injection (all P < .05). Predictors of not achieving the HOS-SS MCID included anxiety/depression, preoperative symptom duration for >2 years, high preoperative HOS-SS score, and preoperative hip injection, while running at least at the recreational level was a predictor of achieving HOS-SS MCID (all P < .05). Predictors of not achieving the mHHS MCID included history of anxiety or depression, high preoperative mHHS score, and hip injections, while being female was predictive of achieving the MCID (all P < .05). Conclusion: This study identified predictive variables for achieving clinically meaningful outcome after hip arthroscopy for FAIS. Patient factors including anxiety/depression, symptom duration >2 years, preoperative intra-articular injection, and high preoperative outcome scores are most consistently predictive of inability to achieve clinically meaningful outcome. These findings have important implications for shared decision-making algorithms and management of preoperative expectations after hip arthroscopy for FAI.

Background: Previous studies have evaluated the effect of distance to high-volume centers on outcomes after joint replacement. However, there is limited evidence on whether this distance has an effect on outcomes after undergoing hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS). Purpose: To determine whether increased distance from a patient’s home to his or her primary orthopaedic clinic has an influence on the ability to achieve the minimal clinically important difference (MCID) on outcome measures after surgery for FAIS. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective cohort analysis was performed on patients undergoing surgery for FAIS by a single surgeon from January 2012 through January 2017. A total of 692 patients were identified and split into 2 groups: driving distance of <50 miles from our institution (referral group) and driving distance of <50 miles from our institution (local group). Preoperative and 2-year postoperative scores on patient-reported outcome measures (PROMs), including the Hip Outcome Score Activities of Daily Living and Sport-Specific subscales, International Hip Outcome Tool–12, and modified Harris Hip Score, were assessed. Patients achieving the MCID on any included PROM were analyzed using a chi-square analysis. Logistic regression was performed to determine whether driving distance and other demographic variables of interest had an effect on achieving the MCID. Study data were analyzed using PatientIQ, a cloud-based research and analytics platform for health care. Results: There were 647 patients who completed 2-year follow-up and were included in the analysis. Of these patients, 116 (17.9%) were identified as being ≥50 miles from their orthopaedic provider, and 531 (82.1%) were identified as having a driving distance of <50 miles. A total of 100 patients (86.2%) in the referral group reached the MCID, and 476 patients (89.6%) in the local group reached the MCID. There was no statistically significant difference in reaching the MCID on any of the included PROMs between the 2 groups ( P = .364). The same result held when controlling for a number of factors including age, body mass index, and adjusted gross income with logistic regression. Conclusion: When controlling for a number of factors including age, body mass index, and adjusted gross income, distance to a high-volume hip arthroscopic surgery center did not have an effect on postoperative outcome scores or achieving the MCID 2 years after undergoing surgery for FAIS.

Purpose To determine factors predictive of patients who are at risk for being lost to follow-up after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Methods A prospective clinical repository was queried between January 2012 and October 2017 and all patients who underwent hip arthroscopy for primary or revision FAIS with minimum 2-year follow-up were included. A total of 27 potential risk factors for loss to follow-up were available and tested for predictive value. An 80:20 random sample split of all patients was performed to create training and testing sets. Cross-validation, minimum Bayes information criteria, and adaptive machine-learning algorithms were used to develop the predictive model. The model with the best predictive performance was selected based off of the lowest postestimation deviance between the training and testing samples. The c-statistic is a measure of discrimination. It ranges from 0.5 to 1.0, with 1.0 being perfect discrimination and 0.5 indicating the model is no better than chance. A log-likelihood χ 2 test was used to evaluate the goodness-of-fit of the logistic regression model. Results A total of 2113 patients were included. Inference of minimum Bayes information criteria model indicated that male sex (odds ratio [OR] 1.82, P = .028), non-white race (African American OR 2.41, P = .013; other non-white OR 1.42, P = .042), smoking (OR 1.07, P = .021), and failure to provide a phone number (OR 1.78, P = .032) increased the risk for being lost to follow-up. Furthermore, greater preoperative International Hip Outcome Tool 12-item component questionnaire (OR 1.03, P = .004), and modified Harris Hip Score (OR 1.05, P = .014) scores increased the risk of being lost to follow-up. The c-statistic was 0.76 (95% confidence interval 0.701-0.848). The log-likelihood indicated that the regression model as a whole was statistically significant ( P = .002). Conclusions Patients who are male, non-white, smokers, fail to provide a telephone number, and have greater preoperative modified Harris Hip Score and International Hip Outcome Tool 12-item component questionnaire scores are at an increased risk for being lost to follow-up 2 years after hip arthroscopy for FAIS. Level of Evidence Level III, case control study

Objectives: To build a statistical model to predict two year-post operative Minimal Clinically Important Differences (MCID) for patient reported outcome scores using only preoperative patient data. Methods: Prospectively collected data of all consecutive hip arthroscopy cases for femoroacetabular impingement (FAI) between January 2012-July 2016 were retrospectively identified from a high-volume, single fellowship trained surgeon. Exclusion criteria included dysplasia, patients without a diagnosis of FAI, and follow-up less than two-years. Predictive models for achieving MCID with respect to HOS-ADL, HOS-SS, and mHHS were each built in the following fashion. To reduce the dataset to its most meaningful features and reduce overfitting, the LASSO algorithm was used. This algorithm fits a model on the full dataset and returns non-zero coefficients for features that are determined to be most descriptive while being generalizable. A receiver operating characteristic (ROC) analysis was then performed on each model. In total, 57 independent features were used for modeling. The selected features are then retained for performing a binary logistic regression analysis. Study data were analyzed using PatientIQ (PatientIQ, Chicago IL 60607), a cloud-based research and analytics platform for healthcare. Results: 2,511 patients were identified within the dataset. After application of inclusion and exclusion criteria 1,194 patients were entered into the modeling algorithm. The following MCID cutoffs were used: HOS-ADL = 9.8, HOS-SS = 14.4, mHHS = 9.14. Of patients entered into the algorithm, 71.7% met the HOS-ADL, 73.7% met the HOS-SS, and 77.7% met mHHS MCIDs cutoffs. All ROC curves showed an area under the curve of greater than 0.84. Predictors of not achieving the HOS-ADL MCID included psychiatric history, symptom duration greater than 2 years, age 30-45 years, obesity, low baseline HOS-ADL, and preoperative injection. Predictors of not achieving the HOS-SS MCID included anxiety and depression, proximal hamstring pain with palpation, symptom duration greater than 2 years, low preoperative HOS-SS, and preoperative injection. Predictors of not achieving the mHHS MCID included presence of asthma, prior narcotic use, preoperative physical therapy, presence of snapping IT band, low preoperative mHHS, and preoperative injection. Predictors of achieving the HOS-ADL MCID included a trochanteric pain sign, and higher preoperative mHHS. Predictors of achieving the HOS-SS MCID included a history of running. Predictors of achieving the mHHS MCID included female gender and digestive health history. Conclusion: Several preoperative factors, including mental health, symptom duration length, non intra-articular hip related pain, and preoperative intra articular injections predict failure to achieve the MCID for several patient reported outcome scores. These findings have implications for managing preoperative expectations and anticipated outcomes following hip arthroscopy for FAI.