TOTAL HIP REPLACEMENT
Total hip replacement is the replacement of a severely damaged hip with an artificial joint. Indications for this surgery include arthritis (degenerative joint disease, rheumatoid arthritis), femoral neck fractures, failure of previous reconstructive surgeries (failed pros-thesis, osteotomy), and problems resulting from congenital hip disease. A variety of total hip prostheses are available. Most consist of a metal femoral component topped by a spherical ball fitted into a plastic acetabular socket (see Fig. 67-6). The surgeon selects the prosthesis that is most suited to the individual patient, considering various factors, including skeletal structure and activity level.
The patient is usually 60 years of age or older and has un-remitting pain or irreversibly damaged hip joints. With the ad-vent of improved prosthetic materials and operative techniques, the life of the prosthesis has been extended, and today younger patients with severely damaged and painful hip joints are under-going total hip replacement.
The nurse must be aware of and monitor for specific potential complications associated with total hip replacement. Complica-tions that may occur include dislocation of the hip prosthesis, excessive wound drainage, thromboembolism, infection, and heel pressure ulcer. Other complications for which the nurse must monitor include those associated with immobility, heterotophicossification (formation of bone in the periprosthetic space), avas-cular necrosis (bone death caused by loss of blood supply), and loosening of the prosthesis.
Maintenance of the femoral head component in the acetabular cup is essential. The nurse teaches the patient about positioning the leg in abduction, which helps to prevent dislocation of the prosthesis. The use of an abduction splint, a wedge pillow (Fig. 67-7), or two or three pillows between the legs keeps the hip in ab-duction. When the nurse turns the patient in bed, it is important to keep the operative hip in abduction. Depending on the sur-geon’s preference, some patients are not permitted to be turned onto the affected side, whereas others may be turned to either side.
The patient’s hip is never flexed more than 90 degrees. To pre-vent hip flexion, the nurse does not elevate the head of the bed more than 60 degrees. For use of the fracture bedpan, the nurse instructs the patient to flex the unaffected hip and to use the trapeze to lift the pelvis onto the pan. The patient is also re-minded not to flex the affected hip.
Limited flexion is maintained during transfers and when sit-ting. When the patient is initially assisted out of bed, an abduc-tion splint or pillows are kept between the legs.
The nurse encourages the patient to keep the affected hip in extension, in-structing the patient to pivot on the unaffected leg with assistance by the nurse, who protects the affected hip from adduction, flex-ion, internal or external rotation, and excessive weight bearing.
High-seat (orthopedic) chairs, semireclining wheelchairs, and raised toilet seats may be used to minimize hip joint flexion. When sitting, the patient’s hips should be higher than the knees. The patient’s affected leg should not be elevated when sitting. The patient may flex the knee.
The nurse teaches the patient protective positioning, which in-cludes maintaining abduction and avoiding internal and external rotation, hyperextension, and acute flexion. A cradle boot may be used to prevent leg rotation and to support the heel off the bed, preventing development of a pressure ulcer. The patient should use pillows between the legs when in a supine or side-lying posi-tion and when turning. Generally, the nurse instructs the patient not to sleep on the side on which the surgery was performed with-out consulting the surgeon. At no time should the patient cross his or her legs. The patient must avoid acute flexion of the hip. The patient should not bend at the waist to put on shoes and socks. Occupational therapists can provide the patient with devices to as-sist with dressing below the waist. Hip precautions are needed for about 4 months after surgery (Chart 67-8).
Dislocation may occur with positioning that exceeds the lim-its of the prosthesis. The nurse must recognize dislocation of the prosthesis. Indicators are as follows:
· Increased pain at the surgical site, swelling, and immobi-lization
· Acute groin pain in affected hip or increased discomfort
· Shortening of the leg
· Abnormal external or internal rotation
· Restricted ability or inability to move leg
· Reported “popping” sensation in hip
If a prosthesis becomes dislocated, the nurse (or the patient, if at home) immediately notifies the surgeon, because the hip must be reduced and stabilized promptly so that the leg does not sus-tain circulatory and nerve damage. After closed reduction, the hip may be stabilized with Buck’s traction or a brace to prevent re-current dislocation. As the muscles and joint capsule heal, the chance of dislocation diminishes. Stresses to the new hip joint should be avoided for the first 3 to 6 months.
Fluid and blood accumulating at the surgical site are usually drained with a portable suction device. This prevents accumulation of fluid, which could contribute to discomfort and provide a site for infection. Drainage of 200 to 500 mL in the first 24 hours is expected; by 48 hours postoperatively, the total drainage in 8 hours usually decreases to 30 mL or less, and the suction device is then removed. The nurse promptly notifies the physician of any drainage volumes greater than anticipated.
If extensive blood loss is anticipated after total joint replace-ment surgery, an autotransfusion drainage system (in which the drained blood is filtered and reinfused into the patient during the immediate postoperative period) may be used to decrease the need for homologous blood transfusions.
The risk for thromboembolism is particularly great after recon-structive hip surgery. The incidence of DVT is 45% to 70%. The peak occurrence is 5 to 7 days after surgery. About 20% of pa-tients with DVT develop pulmonary emboli, of which about 1% to 3% of cases are fatal. Therefore, the nurse must institute pre-ventive measures and monitor the patient closely for the devel-opment of DVT and pulmonary emboli. Signs of DVT include calf pain, swelling, and tenderness. Measures to promote circula-tion and decrease venous stasis are priorities for the patient un-dergoing hip reconstruction. The nurse encourages the patient to consume adequate amount of fluids, to perform ankle and foot exercises hourly while awake, to use elastic stockings and sequential compression devices as prescribed, and to transfer out of bed and ambulate with assistance beginning on the first postoperative day. Low-dose heparin or enoxaparin (Lovenox) is frequently prescribed as prophylaxis for DVT after hip replacement surgery.
Infection, a serious complication of total hip replacement, may ne-cessitate removal of the implant. Patients who are elderly, obese, or poorly nourished and patients who have diabetes, rheumatoid arthritis, concurrent infections (eg, urinary tract infection, dental abscess), or large hematomas are at high risk for infection.
Because total joint infections are so disastrous, all efforts are undertaken to minimize their occurrence. Potential sources of infection are avoided. Prophylactic antibiotics are prescribed. If indwelling urinary catheters or portable wound suction devices are used, they are removed as soon as possible to avoid infection. Prophylactic antibiotics are prescribed if the patient needs any fu-ture surgical instrumentation, such as tooth extraction or cysto-scopic examination.
Acute infections may occur within 3 months after surgery and are associated with progressive superficial infections or hematomas. Delayed surgical infections may appear 4 to 24 months after surgery and may cause return of discomfort in the hip. Infections occurring more than 2 years after surgery are attributed to the spread of in-fection through the bloodstream from another site in the body. If an infection occurs, antibiotics are prescribed. Severe infections may require surgical débridement or removal of the prosthesis (Nursing Research Profile 67-1).
Before the patient prepares toleave the acute care setting, the nurse provides a thorough teaching program to promote continuity of the therapeutic regimen and ac-tive participation in the rehabilitation process (Chart 67-9). The nurse advises the patient of the importance of the daily exercise program in maintaining the functional motion of the hip joint and strengthening the abductor muscles of the hip, and reminds the pa-tient that it will take time to strengthen and retrain the muscles.
Assistive devices (crutches, walker, or cane) are used for a time. After sufficient muscle tone has developed to permit a normal gait without discomfort, these devices are not necessary. In general, by 3 months, the patient can resume routine ADLs. Stair climbing is permitted as prescribed and is kept to a minimum for 3 to 6 months. Frequent walks, swimming, and use of a high rocking chair are ex-cellent for hip exercises. Sexual activities should be carried out with the patient in the dependent position (flat on the back) for 3 to 6 months to avoid excessive adduction and flexion of the new hip.
At no time during the first 4 months should the patient cross the legs or flex the hip more than 90 degrees. Assistance in putting on shoes and socks may be needed. The patient should avoid low chairs and sitting for longer than 45 minutes at a time. These pre-cautions minimize hip flexion and the risks for prosthetic dislo-cation, hip stiffness, and flexion contracture. Traveling long distances should be avoided unless frequent position changes are possible. Other activities to avoid include tub baths, overexertion, jogging, lifting heavy loads, and excessive bending and twisting (eg, lifting, shoveling snow, forceful turning).
The nurse maymake a home visit to assess for potential problems and to monitor wound healing (see Chart 67-9). The nurse, physical therapist, or occupational therapist assesses the home environment for physical barriers that may impede the patient’s rehabilitation. In addition, the nurse or therapist may need to assist the patient in acquiring de-vices, such as reachers to help with dressing or toilet seat extenders.
After successful surgery and rehabilitation, the patient can ex-pect a hip joint that is free or almost free of pain, has good mo-tion, is stable, and permits normal or near-normal ambulation (see Plan of Nursing Care).