Insurance and Socioeconomic Disadvantage in Patients with Multiligament Knee Injury: Associations with Demographics, Mechanism, and Severity

Abstract

Background: Multiligament knee injuries are complex injuries frequently complicated by vascular and nerve injuries involving the tibiofemoral joint resulting from a multitude of mechanisms. By definition, they must involve partial or complete tear of ≥2 of the 4 major knee ligaments. Beyond injury mechanism, social determinants of health have an established influence on orthopedic outcomes, but an association has not been investigated between multiligament knee injuries and these social factors.

Aims: To analyze demographic profiles, insurance types, and area deprivation scores to determine if a correlation could be found between socioeconomic status and injury severity (polytrauma vs non-polytrauma) and mechanisms (high energy vs low energy) leading to multiligament knee injuries.

Methods: This is a retrospective review of multiligament knee injury patients surgically treated at a single institute. Sociodemographic information, clinical records, and surgical reports were collected. Insurance types were stratified into private, public (Medicaid/Medicare), or other (workers’ comp, auto, charity, uninsured), and area deprivation index was collected using patient addresses. Patients with insufficient records were excluded from the study. Subgroup analyses were done on sex, age, body mass index, polytrauma status, and high energy versus low energy mechanism.

Results: A total of 218/264 patients (82%) with multiligament knee injuries were eligible. 70% were privately insured, 21% had public insurance, and 9% had other insurance. Private insurance mean age was 27.6, public 28.4, and other 36.2 (P=0.021). Private insurance had a mean body mass index of 27.2 versus 30.9 for public and 32.8 for other (P=<0.001). Area deprivation score percentile was significantly different: 29.1 private versus 39.6 public versus 38.8 other (P=0.002). Public insurance (B, +8.93; p=0.006) and other insurance (B, +10.04; p=0.030) were independently associated with area deprivation score. Only high energy injury mechanism (OR, 87.83; p=<0.001) was associated with polytrauma. Male sex (OR 3.67; p=0.005), age (OR, 1.05; p=0.003), and polytrauma (OR, 94.44; p=<0.001) were associated with high energy mechanism.

Conclusion: Socioeconomic disadvantage, defined by insurance type and area deprivation score, was associated with demographic differences but did not predict high energy mechanism or polytrauma status in multiligament knee injury patients. These findings reinforce that multiligament knee injury severity is linked to biomechanical and demographic factors rather than social factors.