Increased Readmission Rates but No Difference in Complication Rates in Patients Undergoing Inpatient Versus Outpatient Hip Arthroscopy: A Large Matched-Cohort Insurance Database Analysis

Purpose: To compare the early postoperative outcomes of patients undergoing inpatient versus outpatient hip arthroscopy and identify any characteristics that may serve as predictors of these complications Methods: The PearlDiver Mariner insurance database was queried for all patients who underwent hip arthroscopy from 2010 to 2019. Patients were matched based on Charlson Comorbidity Index, age, and sex. Outcomes recorded included postoperative complications and return to care within 90 days. Predictors of complications were assessed via multivariable logistic regression controlling for age, sex, Charlson Comorbidity Index, comorbidities, surgical setting, and procedure type Results: The final matched cohort included 832 inpatients and 1,356 matched patients. Fifty-eight patients (7.0%) who underwent inpatient surgery versus 25 patients (1.8%) who underwent outpatient surgery were readmitted (P < .01). Of the readmitted patients, 31 inpatients (3.7%) and 5 outpatients (0.4%) were readmitted for hip-related reasons (P < .01). No significant differences were observed in emergency department visits (67 inpatients [8.1%] vs 84 outpatients [6.2%], P = .11), intensive care unit admissions (3 [0.4%] vs 1 [0.1%], P = .31), or revision hip arthroscopies (43 [5.2%] vs 65 [4.8%], P = .77). A multivariable model of complications correcting for baseline differences in chronic obstructive pulmonary disease, coronary artery disease, diabetes, hypertension, ischemic heart disease, tobacco use, and inpatient status found that age (adjusted odds ratio [OR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .03), coronary artery disease (adjusted OR, 12.82; 95% CI, 1.18-140.02; P = .03), and inpatient setting (adjusted OR, 20.59; 95% CI, 3.48-401.65; P = .01) were significantly associated with complications. No procedure type was associated with complication rates Conclusions: Compared with the outpatient setting, inpatient hip arthroscopy is associated with higher rates of readmission in a cohort matched for age, sex, and comorbidities. Complications after inpatient hip arthroscopy appear to be related to comorbidities rather than procedure-related factors. The decision to conduct an inpatient hip arthroscopy should prioritize consideration of patient comorbidities over the type of procedure Level of Evidence: Level III, retrospective cohort study.