National trends, 90-day readmission and subsequent knee surgery following multi-ligament knee reconstruction.

INTRODUCTION/
BACKGROUND: Given the uncommon nature of the multi-ligament injured knee, a better understanding of its outcomes may be achieved by contemporary evaluation of a national administrative database. We aim to identify risk factors for 90-day major complications, 90-day readmissions, and subsequent knee surgery after a multi-ligament knee reconstruction.
METHODS: The Humana Claims Database was queried for all patients undergoing a multi-ligament knee reconstruction procedure from 2007 to 2016 using International Classification of Diseases (ICD)-9 procedure codes and Current Procedural Terminology (CPT) codes. Outcomes of interest included Center of Medicaid and Medicare Services (CMS)- reportable 90-day complications, 90-day readmission and subsequent ligament reconstruction or total knee arthroplasty. Predictive factors studied included demographics (ie. age, sex, tobacco use) comorbidity burden and operative factors (ie. surgical setting, diagnosis of knee dislocation, concomitant meniscal repair or meniscectomy).
RESULTS: 588 multi-ligament knee reconstruction procedures were identified. The 90-day readmission rate 8.3%. The rate of subsequent ligament surgery was 7.1%. On multivariate regression analysis, a diagnosis of knee dislocation was associated with a four times greater likelihood of readmission and a two and a half greater likelihood of subsequent ligament surgery. Concomitant meniscectomy was associated with higher likelihood of subsequent total knee arthroplasty (9.1, 1.4-67.0) and outpatient setting of surgery compared to inpatient hospital setting was associated with reduced likelihood of readmission.
CONCLUSION: While uncommon, the patient population undergoing multi-ligament knee surgery is relatively diverse. Understanding common factors predisposing this population to adverse events following surgery may assist in improved outcomes.