A car running over a foot causes a severe crush injury, resulting from the foot being compressed between the tire and the ground. The foot’s complex anatomy, which includes 26 bones, 33 joints, and over 100 tendons and ligaments, makes it highly vulnerable to trauma. Injuries can range dramatically in severity, affecting the skin, soft tissue, bones, blood vessels, and nerves. Even if the injury appears minor initially, a high-energy crush injury requires immediate professional medical evaluation due to the potential for serious, unseen complications.
Variables Determining Injury Severity
The extent of damage is largely determined by the physics of the crush event. The weight of the vehicle is a major factor, as heavier vehicles like SUVs or trucks transmit significantly greater force than compact cars. Vehicle speed is also important; a slow roll causes a different injury type than a quick movement, which may introduce shearing forces.
The tire tread design also plays a role, as aggressive treads can cause more deep-tissue lacerations and soft tissue damage. The exact impact area dictates which structures absorb the force; a strike to the midfoot often results in more complex bone and joint injuries than an impact to the forefoot. Immediate signs of extreme severity include visible deformity, an open wound with bone protrusion, or loss of circulation indicated by pale or cool toes.
Immediate First Aid and Emergency Steps
A crush injury requires immediate attention. Call for emergency medical services if there is severe pain, visible deformity, or loss of sensation. While waiting for help, immobilize the affected limb to prevent further damage to injured tissues or fractured bones. Elevate the foot above the level of the heart if possible to minimize rapid swelling.
Gentle cooling can be applied using an ice pack wrapped in a thin towel, avoiding direct contact with the skin. Do not attempt to remove the shoe or sock if the foot is visibly deformed or swelling rapidly. Removing footwear in these cases could displace fractured bones, increase bleeding, or compromise the remaining blood supply.
Specific Types of Foot and Ankle Damage
Crush injuries often cause complex damage to the foot’s intricate structure. Bone injuries are common, frequently including multiple metatarsal fractures (breaks in the long bones extending to the toes). A more serious pattern is the Lisfranc injury, which involves a fracture or dislocation of the joints where the metatarsals meet the tarsal bones in the midfoot.
The Lisfranc injury is a high-energy trauma sometimes mistaken for a sprain, which can lead to debilitating long-term outcomes if missed. Beyond skeletal damage, the force causes severe soft tissue injury, deep lacerations, and vascular compromise, impairing blood flow. Intense pressure can also lead to compartment syndrome, a serious, time-sensitive complication requiring rapid treatment.
Compartment syndrome occurs when swelling or bleeding within the tight fascial compartments of the foot causes pressure to build to dangerously high levels. This pressure restricts blood flow, depriving muscles and nerves of oxygen and leading to tissue death (necrosis).
Professional Diagnosis and Treatment Protocols
Upon arrival, the initial assessment involves a physical examination to check for open wounds, deformities, and the foot’s neurological and vascular status. Diagnostic imaging determines the full extent of the damage, beginning with X-rays to identify fractures. For complex bone involvement, a Computed Tomography (CT) scan provides detailed cross-sectional images. A Magnetic Resonance Imaging (MRI) scan may be ordered if significant soft tissue damage, tendon rupture, or vascular injury is suspected.
Treatment depends on the diagnosis. Less severe injuries are managed non-surgically with immobilization (cast or splint) and RICE (rest, ice, compression, elevation) protocols. Severe crush injuries often require surgical intervention, such as internal fixation using plates and screws to stabilize fractures and dislocations. For confirmed compartment syndrome, an emergency fasciotomy is performed to relieve high pressure by cutting the fascial compartments. Following initial treatment, rehabilitation involves physical therapy to restore mobility, strengthen muscles, and regain full function.