Arm and Leg Fractures

Arm and leg fractures usually result from trauma and commonly cause substantial muscle, nerve, and other soft-tissue damage. The prognosis varies with the extent of disablement or deformity, the amount of tissue and vascular damage, the adequacy of reduction and immobilization, and the patient’s age, health, and nutritional status.
Children’s bones usually heal rapidly and without deformity. Bones of adults in poor health and with impaired circulation may never heal properly. Severe open fractures, especially of the femoral shaft, may cause substantial blood loss and life-threatening hypovolemic shock.

Causes
Most arm and leg fractures result from major trauma—for example, a fall on an outstretched arm, a skiing accident, or child abuse (shown by multiple or repeated episodes of fractures). However, in a person with a pathologic bone-weakening condition, such as osteoporosis, bone tumors, or metabolic disease, a mere cough or sneeze can also produce a fracture. Prolonged standing, walking, or running can cause stress fractures of the foot and ankle—usually in nurses, postal workers, soldiers, and joggers.

Signs and symptoms
Arm and leg fractures may produce any or all of the five Ps: pain and point tenderness, pallor, pulse loss, paresthesia, and paralysis. (The last three are distal to the fracture site.) Other signs include deformity, swelling, discoloration, crepitus, and loss of limb function. Numbness and tingling, mottled cyanosis, cool skin at the end of the extremity, and loss of pulses distal to the injury may indicate arterial compromise or nerve damage. Open fractures also produce an obvious skin wound.

Complications of arm and leg fractures include:

• hypovolemic shock as a result of blood vessel damage (This is especially likely to develop in patients with a fractured femur.)
• permanent deformity and dysfunction if bones fail to heal (nonunion) or heal improperly (malunion)
• aseptic necrosis of bone segments from impaired circulation
• muscle contractures
• renal calculi from decalcification (produced by prolonged immobility)
• fat embolism.

DiagnosisA history of trauma and a physical examination, including gentle palpation and a cautious attempt by the patient to move parts distal to the injury, suggest an arm or a leg fracture.
When performing the physical examination, also check for other injuries. Anteroposterior and lateral X-rays of the suspected fracture as well as X-rays of the joints above and below it confirm the diagnosis.

Treatment
The following treatments are performed in patients with an arm or leg fracture.
With severe fractures that cause blood loss, direct pressure should be applied to control bleeding and fluids should be administered as soon as possible to prevent or treat hypovolemic shock.

Reduction
After a fracture has been confirmed, treatment begins with reduction (which involves restoring displaced bone segments to their normal position).

After reduction, the fractured arm or leg must be immobilized by a splint or a cast or with traction. With closed reduction (which is accomplished by manual manipulation), a local anesthetic (such as lidocaine) and an analgesic (such as morphine I.M.) help relieve pain, whereas a muscle relaxant or a sedative facilitates the muscle stretching necessary to realign the bone.

An X-ray study is ordered to confirm that reduction has been successful and that proper bone alignment has been achieved.

When closed reduction is impossible, open reduction during surgery reduces and immobilizes the fracture by means of rods, plates, or screws. Afterward, a plaster cast is usually applied.

When a splint or cast fails to maintain the reduction, immobilization requires skin or skeletal traction, using a series of weights and pulleys.

With skin traction, elastic bandages and sheepskin coverings are used to attach traction devices to the patient’s skin. With skeletal traction, a pin or wire inserted through the bone distal to the fracture and attached to a weight allows more prolonged traction.

Other measures
Treatment of open fractures also requires tetanus prophylaxis, a prophylactic antibiotic, surgery to repair soft-tissue damage, and thorough debridement of the wound.