Pathophysiology
Clinical meaning
Traction applies a pulling force to a body part to realign fracture fragments, reduce dislocations, relieve muscle spasm, and prevent deformity. The fundamental principle involves applying a continuous force (traction) along the long axis of the bone, opposed by a counter-traction force (usually the patient's body weight). Skin traction (Buck's, Russell's, Bryant's) applies force through adhesive strips, wraps, or boots attached to the skin surface, limited to 5-10 pounds to prevent skin breakdown. Skeletal traction applies force directly through bone via pins (Steinmann), wires (Kirschner), or tongs (Gardner-Wells, Crutchfield) inserted into bone, allowing heavier weights (up to 25-40 pounds) for large bone fractures. The applied weight must overcome muscle spasm and contractile force to maintain fracture alignment. Counter-traction is achieved through body positioning, bed elevation, or manual resistance. Complications arise from prolonged immobilization: venous stasis increases DVT risk per Virchow triad, disuse atrophy occurs when type II muscle fibers atrophy within days of immobilization, and osteoclast activity exceeds osteoblast formation leading to disuse osteoporosis.