Casts and splints

Anatomy or system affected: Arms, bones, hands, joints, knees, legs, ligaments, musculoskeletal system, neck, nose, skin, tendons

Definition: Casts are solid, firm dressings formed with plaster of Paris or similar material around a limb or other body part to provide immobilization for healing. Splints are orthopedic devices made from rigid metal or plaster or from flexible felt or leather that support, immobilize, or restrain any part of the body during the healing process.

Indications and Procedures

The general objectives of fracture repair are to realign the bone fragments, to maintain the alignment by immobilization, and to restore function to the limb or part. Closed reduction is the manipulation of the bone fragments until the bone is realigned. Manual traction and rotation of the limb may be necessary. This type of reduction is done with a general anesthesia or sedation. The realigned bone is then immobilized by application of a cast or splint. Immobilization is essential after the fracture is realigned. If the bone fragments are not immobilized, then the necessary hematoma and callus formation will be disrupted and the bone will heal slowly, in poor alignment, or fail to heal. Restoration of function is accomplished by preventing complications during immobility and by rehabilitation methods that prepare the patient for mobility and maintain muscle strength, tone, and range of motion.

Uses and Complications

Complications of fractures include infection (osteomyelitis), problems of bone union, compartment syndrome, nerve damage, and cast syndrome. Delayed union of the fracture occurs when the bone does not unite in the usual amount of time. The delay may have various causes, including infection, poor circulation to the bone, and inadequate reduction. Nonunion is the failure of healing so that firm union does not take place. Malunion is a complication in which union occurs in a deformed or angulated position. Compartment syndrome occurs when swelling develops within a confined space. Tight splints and casts may cause pressure from outside the compartment, or inflammation and resulting edema or hemorrhage may cause pressure from within, compromising circulation in the extremity. Ischemia of the muscle occurs if enough pressure builds and leads to nerve damage. The first symptom of compartment syndrome is pain that increases in severity and is unrelieved by narcotics. Other symptoms and signs include paralysis, paresthesias, and decreased or absent pulses. Irreversible damage begins in the muscles and nerves after six hours of ischemia, and the extremity becomes useless after twenty-four to forty-eight hours with loss of motor and sensory function. Nerve damage can result from the original injury itself or from the casting. Cast syndrome, a complication of body casts, is caused by compression of part of the duodenum (the upper part of the small intestine) by the superior mesenteric artery, resulting in gastric or intestinal obstruction. The condition can become fatal if allowed to progress. Treatment includes gastrointestinal decompression, no intake of food or fluid by mouth, fluid and electrolyte intravenous replacement, and removal of the cast.

Nursing management of fracture patients involves efficient care of the cast. Analgesics are administered prior to cast application, if needed. The skin under the area of the cast will be inspected for redness, abrasions, open lesions, or bruising. These areas will need careful evaluation through a cast window to determine that the skin is not breaking down. The skin will be cleaned and dried thoroughly. A tubular stockinette long enough to extend beyond both edges of the cast will be applied to the limb. Rolls of a feltlike material are wrapped around the limb. Bony prominences are wrapped sufficiently to prevent friction and pressure from the cast when applied. The plaster cast is applied over the protective coverings. An X-ray should be taken to ensure proper bone alignment following cast application. The nurse will teach the patient to avoid allowing any objects or crumbs to fall under the cast, as such objects would become pressure points and could cause skin breakdown. The patient should be taught not to scratch under the cast with any object. If itching occurs, then the cool air of a hair dryer may be directed through the open end of the cast to alleviate the sensation. The nurse will monitor the casted limb for odors indicating infection. Hot spots along the cast may also be an indication of infection of the skin underneath. Drainage through the cast is a sign of infection or bleeding. A patient who believes that bleeding has occurred should circle the drainage area with ink and label the date and time on the cast. The nurse should remember to check the undersurface of the cast, as drainage flows downward. The creation of a cast window to expose the area of skin that requires care may be necessary.

Neurovascular assessment should be made frequently for the first twenty-four hours following application of a cast. If neurovascular impairment is not recognized early, then irreversible damage can result with loss of function or even loss of the extremity. These assessments include evaluating the circulatory status—color, temperature, capillary refill, edema, and pulses. Neurologic status includes sensation, mobility, presence of numbness and tingling, or pain. Patients should be taught to self-monitor and self-evaluate their casted extremity.

When the fracture is healed, the cast is split with an electric cast remover that vibrates rather than cuts. The patient will feel only pressure, vibration, and heat. When the cast is removed, the extremity will appear thin and flabby, and the skin will be scaly and may be foul smelling. The nurse should prepare the patient for the appearance of the limb, explaining that when the part begins to be used once again, the muscle will return to its former size. The weakened limb will need support when moved; it may be painful. The limb can swell if held in a dependent position. Patients will be instructed to continue to elevate the extremity and should be reassured that with activity and exercise the tendency for swelling will subside.

Perspective and Prospects

Humans have had to contend with broken or malformed bones since prehistory. Ancient Egyptian hieroglyphics depict injured limbs wrapped and braced to heal normally. The earliest methods of holding a reduced fracture involved using splints. These are rigid strips laid parallel to each other alongside the bone. The Egyptians used wooden splints made of bark wrapped in linen. Plaster of paris bandages were introduced in different forms by a surgeon in the Dutch army in 1851. The bandages hardened rapidly with an exact fit. Though plaster of paris remained the benchmark material in orthopedic immobilization through the early twenty-first century, in early 2023, compostable material, such as SynThetic, began being used.

Bibliography

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