Strain rate sensitivity of combined knee ligament injuries

The effects of clinically applicable strain rates on the injury pattern of knee ligaments were investigated. An experimental model was created to evaluate the effects of strain rate on the injury mechanism of the anterior and posterior cruciate ligaments. Utilizing knee hypertension to rupture the anterior and posterior cruciates, two strain rates were selected to reproduce two clinical injury patterns: low and high energy. It was found that strain rate sensitivity of the posterior cruciate ligament occurs with high rate injuries producing ligament avulsions and slow rates producing midsubstance tears. Anterior cruciate ligament tears occur in a variable pattern and the specific injury mechanism may involve both strain rate and notch morphology.