A traction splint is a specialized medical device used in emergency settings to stabilize specific long bone fractures, primarily in large, muscular limbs. It applies a steady, continuous pulling force along the limb’s axis to temporarily realign broken bone fragments. This prehospital intervention aims to make patient transport safer and more comfortable before definitive care in a hospital.
Defining Traction Splints
The traction splint structure involves a rigid frame, often made of lightweight aluminum poles, which extends the length of the injured limb. At the upper end, a stationary point, frequently a padded cushion or ring, rests against the pelvis near the ischial tuberosity to provide counter-pressure.
The distal end features an ankle hitch, a strap or harness that wraps securely around the ankle and foot. This hitch connects to a tensioning device, such as a ratchet or screw mechanism, used to generate the controlled pulling force. Securing straps are also used along the limb to keep the leg cradled and prevent rotation or movement of the fracture site.
Primary Function and Application
The specific medical indication for a traction splint is primarily a fracture of the mid-shaft of the femur, the large bone in the thigh. The splint’s main function is to stabilize this fracture, which is often caused by high-energy trauma like vehicle accidents.
The splint also minimizes the potential for large internal blood loss, as the thigh can hold up to three liters of hemorrhaged blood. Keeping the bone ends aligned helps to stabilize clots and reduce the volume of internal bleeding into the surrounding soft tissues. The splint also prevents further soft tissue damage and potential injury to nerves or blood vessels caused by sharp, moving bone fragments during transport.
The Mechanism of Action
The effectiveness of the traction splint relies on overcoming the powerful muscle contractions that occur following a fracture. When the femur breaks, the large, strong muscles surrounding it, such as the quadriceps and hamstrings, involuntarily spasm. This muscle spasm pulls the two broken bone ends past one another, causing them to overlap and shorten the limb, which results in significant pain and pressure.
The traction splint applies a steady pulling force to the limb distal to the fracture. This force directly counteracts the powerful, shortening pull exerted by the spastic muscles. Maintaining this constant counter-force fatigues the muscles in spasm, allowing the limb to be gently pulled back toward its normal anatomical length. This temporary realignment reduces soft tissue pressure, diminishes the patient’s pain, and prevents the bone ends from grinding together. The amount of traction applied is carefully controlled, often aiming for about ten percent of the patient’s body weight, with a maximum limit.
Situations Where They Are Not Used
Traction splints are not appropriate for all lower extremity injuries, and their use is governed by specific contraindications. Applying traction can be harmful if the injury is located near a joint. Fractures involving the knee, ankle, or hip are reasons to avoid using a traction splint, as the pulling force could worsen a ligament or joint injury.
The device is also contraindicated if the patient has a suspected pelvic fracture, as the counter-pressure pad of the splint rests against the pelvis, potentially causing further injury. If a patient has multiple fractures in the same leg, such as a mid-shaft femur fracture combined with a lower leg fracture, the traction force would pull apart the weaker, more distal fracture site instead of realigning the femur. In cases of partial amputation where only marginal tissue connects the distal limb, applying traction could complete the separation.