Abstract
The purpose of this study is to identify risk factors for readmission after anterior
cruciate ligament (ACL) reconstruction and to determine costs associated with readmission.
Using a private insurance claims' database, we identified patients who underwent ACL
reconstruction from 2010 to 2015 using the International Classification of Diseases,
Version 9 (ICD-9) and Current Procedural Terminology (CPT) codes. Univariate analysis
was performed on demographic data, surgical characteristics, and comorbidities. Variables
with p < 0.10 were added to a multivariate logistic regression model which was created to
identify independent risk factors for all-cause readmission within 90 days postoperatively.
Significance was considered at p < 0.05. Overall, 90,263 patients were included (average age: 29 ± 13 years, 44% female),
and 1,066 (1.2%) of patients had a hospital readmission within 90 days following surgery.
Risk factors for hospital readmission included cerebrovascular disease (odds ratio
[OR] = 3.4, 95% confidence interval [CI]: 1.9, 6.2), diabetes mellitus (OR = 2.6,
95% CI: 1.9, 3.5), concomitant medial collateral ligament (MCL) or lateral collateral
ligament (LCL) reconstruction (OR = 2.5, 95% CI: 1.9, 3.3), concomitant posterior
cruciate ligament (PCL) reconstruction (OR = 2.2, 95% CI: 1.4, 3.3), age between 44
and 65 years (OR = 2.1, 95% CI: 1.6, 2.9), and depression (OR = 1.88, 95% CI: 1.49,
2.38, p < 0.001). Female sex was associated with decreased odds of 90-day hospital readmission
(OR = 0.8, 95% CI: 0.7, 0.9). Each hospital readmission accounted for an estimated
$17,841 (95% CI: $17,173, 18,509) in gross health care payments, and patients with
readmissions had substantially higher 1-year cumulative health care costs. Readmission
after ACL reconstruction was 1.2%. The strongest risk factors for 90-day readmission
include cerebrovascular disease, diabetes mellitus, concomitant MCL/LCL reconstruction,
concomitant PCL reconstruction, and age between 44 and 65 years. Readmission was associated
with substantial health care costs.
Keywords
anterior cruciate ligament - ACL reconstruction - readmission - cost - risk factors
