Many models have been employed to replicate skeletal muscle injury associated with trauma; however, most are restricted to 1 level of severity.
To create and validate an injury-producing device that could generate multiple levels of injury severity.
Patients or Other Participants:
Twenty-six male Wistar rats, 3 to 4 months old.
A contusion device was developed and its ability to deliver consistent impacts was validated alone and in the presence of an experimental animal. A free-falling mass (267 g) was adjusted to the desired height (40, 50, 60, or 70 cm) and then dropped.
Main Outcome Measure(s):
Peak load, peak displacement, impulse, energy, and velocity peak were measured. Injury severity was determined using magnetic resonance imaging.
Outcome measures observed from the device alone were different by height (F18,136 = 21.807, P < .001, 1−β = 1.0). Outcomes using the experimental animals were also dependent on height (F14,102 = 68.679, P < .001, 1−β = 1.0). Linear regression analyses indicated that height accounted for 17% to 89% of the variance.
Mild to moderate and moderate to severe injuries can be replicated with this device, which will be useful in evaluating clinical treatments on acute muscle injury.