Epidemiology of complete knee dislocations: an updated classification system

Area of Science:

• Orthopedic Surgery
• Trauma Care
• Biomechanics

Background:

• Complete knee dislocations involve complex injuries often underestimated by current classifications.
• These injuries significantly impact patient outcomes.
• A need exists for a more comprehensive classification system.

Purpose of the Study:

• To evaluate the epidemiology of complete knee dislocations.
• To present an updated, experience-based classification system for these severe injuries.

Main Methods:

• Retrospective analysis of patients (≥18 years) with complete knee dislocation admitted to a Level-I trauma center (2002-2019).
• Data collected via Hospital Information System (HIS) using ICD-10 codes.
• Identification of concomitant ligamentous, bony, meniscal, and neurovascular injuries.

Main Results:

• 80 patients included; majority male (80%), mean age 34.9 years.
• High rates of concomitant injuries: ACL (55%), PCL (56.3%), collateral ligaments (32-47.5%), menisci (30-31.1%).
• Neurovascular involvement in 13.8% of cases; external fixation in 40%.

Conclusions:

• Current knee dislocation classifications are insufficient for severe injuries.
• Concomitant injuries (ligamentous, neurovascular, bony, meniscal) are frequent and require staged procedures.
• A new Grade A-D classification system is proposed to better rank injury severity.