The earlier attempts at hip arthroplasty between the 1700s and the 1950s were in response to the number of wounded soldiers in Europe and the United States receiving amputation as a treatment for injuries that may have occurred months before arriving to port. Anesthesia wasn't available during the 1700s, so amputations were performed quickly and routinely.

There are a few conditions that can affect the hip so severely that hip replacement surgery becomes necessary. Avascular necrosis, osteoarthritis, and rheumatoid arthritis are three diseases that can cause pain and limited mobility in the hip joint as well as other joints of the body (see How arthritis and osteonecrosis take a toll on joints).

Avascular necrosis

Avascular necrosis of the hip is characterized by a disruption of the blood supply to the bone resulting in the breakdown of the hip joint. It can be caused by a dislocation, trauma, or diseases such as lupus, sickle-cell disease, kidney disease, and clotting disorders.

There are two types of osteoarthritis: idiopathic and secondary. Idiopathic osteoarthritis occurs in individuals with no known injury or disease etiology. Secondary osteoarthritis has an identifiable cause and is the result of injury or trauma to the bone, such as a hip fracture or high-demand activities.

Rheumatoid arthritis is a chronic systemic inflammatory disease that affects peripheral joints and surrounding structures, including muscles, tendons, and ligaments (see Rheumatoid arthritis of the hip). The condition can be very aggressive, causing severe synovial hypertrophy and bone and joint destruction. Medical care for this disease is usually provided by a rheumatologist.

Nonsurgical treatments for hip pain

Hip pain and limited mobility are usually the reasons people visit a primary care provider to obtain a referral to an orthopedic surgeon. Arthritis sufferers often state they're in constant pain, have difficulty walking, and can't enjoy earlier activities. In the early stages of arthritis, a complaint of stiffness, swelling, and pain may occur when walking and is relieved by periods of rest.

Heat, cold therapy, physical therapy, and analgesics are conservative measures used to treat hip pain. Once conservative measures fail and arthritis progresses, patients complain of pain even when the joint is at rest. When the patient reports no benefit from conservative therapy, suffers pain at rest and on ambulation, and the adverse reactions from the treatments outweigh the benefits, total hip arthroplasty may be recommended.

Selecting candidates

The patient is examined for hip range of motion, palpation tenderness over bony landmarks, and leg lengths. Many chief complaints of hip pain turn out to be other problems not associated with the hip. The differential diagnosis includes arthritis of the lumbar spine, intermittent claudication resulting from insufficient arterial blood flow to the leg, and inguinal hernias. The diagnosis can usually be confirmed by X-rays of the hip.

When deciding whether a patient is a candidate for hip replacement, the surgeon considers the patient's age, general medical condition, degree of pain, failure of conservative measures, and the degree to which the disease has affected the patient's mobility. Another important consideration is whether the patient is emotionally ready for surgery.

Preadmission

Because total joint replacement surgery is usually always elective, patients are encouraged to prepare ahead of time for their hospitalization. Early preparation for joint replacement surgery includes a thorough medical examination and dental checkup. Patients preparing for surgery should also have a support system in place to assist with recovery at home if needed.

Nurses in the preadmission testing area call patients approximately 2 weeks prior to surgery to discuss their medical profile. The medical profile becomes a permanent part of the medical record and sets the standard for other testing that may be necessary before the patient's pending procedure. A history and physical exam will be completed no more than 30 days prior to the surgery. Patients who need additional testing due to chronic medical conditions are required to obtain clearance from a specialist.

At the authors' institution, 1 to 2 weeks prior to surgery, the joint replacement coordinator at the authors' institution will contact the patient to attend a class explaining the upcoming surgery, which includes a video presentation of the joint replacement process. The classes are offered twice a month, one session in the morning and one in the evening.

The hospital dietitian discusses nutritional information for patients who have specific health needs such as diabetes, obesity, and those who will be taking anticoagulants upon discharge. The program coordinator talks about the hospitalization and the patients are shown models of the hip and work with appliances such as the hip abduction pillow, sock-aids, walkers, and canes. A physical therapist talks about the goals of therapy and assists patients in planning for rehabilitation or home care.

The procedure

Patients are taken to the holding area of the OR where they meet with the surgeon, nurse, and anesthesiologist. The surgeon confirms the correct site with the patient and marks the hip as discussed in previous office visits. The patient is taken into the OR and placed in the lateral decubitus position, and the leg is then prepped and draped.

The surgeon can approach the hip from the anterior or posterior position. The incision is made and the surgeon separates the thighbone from the socket (dislocating the hip). Working between the larger hip muscles, the surgeon removes the diseased or damaged bone and tissue, leaving the healthy bone and tissue intact.

There've been many advances in hip replacement surgery. Presently, the femoral component is designed to be cemented or noncemented which allows the body to grow into the prosthesis (bony ingrowth). The cement wedges the prosthesis into the canal of the femur. Cementing techniques have been improved by the use of suction to remove air by mixing and the incorporation of antibiotics into the cement. The cements are also much stronger and set faster. Noncemented components are covered by a porous coating that allows the body to grow into the edges of the prosthesis.

Every femoral component has a ball at its end known as the femoral head. Recent changes include making the femoral heads larger, which has improved the wear pattern of the hip and decreased the complication of dislocation of the hip.

The acetabulum is typically not cemented. It's surrounded by a porous coating that allows bony ingrowth into the prosthesis. The acetabulum can be fixed to the pelvic bone by using screws through the cup.

Between the prosthetic metal cup and the prosthetic metal ball placed in the hip during surgery is a polyethylene liner that fits securely into the metal cup. This plastic is stronger than previous materials and lasts longer.

Current trends

The current trend in total hip replacement is to minimize surgical exposure. Less trauma to the surrounding muscles helps to expedite postoperative recovery. Many surgeons use X-ray during the procedure to help confirm the positioning of the components through small incisions. One such procedure is the mini-hip incision.

The mini-hip incision for hip replacement is good news for patients needing a standard hip replacement. The major benefit is a smaller incision, which may be 4 to 5 inches in length rather than the standard 8 to 10-inch incision. Other benefits include less blood loss, faster rehabilitation, and decreased pain because there's less trauma to the surrounding tissue.

Complications of the procedure include bleeding, infection, hip dislocation, deep venous thrombosis (DVT), pulmonary embolus, leg length inequality, and loosening of the components. Prophylactic antibiotics are given within 1 hour of the surgical incision in all cases. DVT prophylaxis is given for 2 to 3 weeks following the surgery. (See Managing blood loss.)

The standard of care for hip replacement patients is dictated by the use of pathways and procedures. The Clinical Pathway Committee uses a group of standardized clinical interventions based on a patient's diagnosis or set of symptoms. At the authors' facility, the clinical process is reviewed by clinical leadership, occupational and physical therapists, nursing staff, nurse practitioners, and physician's assistants, and an order set is developed. The order set is refined through feedback and approval from the pathway committee. Clinical practice guidelines are also dictated using evidence-based practice. As new evidence is obtained, policies and procedures are revised accordingly.

Pain management

It's important for the patient to know that each person's response to pain is unique. Patients undergoing hip replacement surgery are often given spinal, general, or epidural anesthesia.

Spinal and epidural anesthesia may assist patients with pain relief several hours after administration of the medication, which may contain a local anesthetic and possibly an opioid.

Patients who don't obtain adequate pain relief from patient-controlled analgesia, epidurals, spinals, or opioids may require additional management.

Postoperative therapy

When pain control is achieved, the patient can begin therapy. Patients are assisted out of bed and helped to ambulate with physical therapy the day after surgery. It's important that the patient is hemodynamically stable before the therapist ambulates the patient. Hypotension may be an issue, so the nurse will often withhold diuretics and some antihypertensive medications the day after surgery with the consent of the prescriber until the patient is stable. Patients who are hypotensive may be given a fluid bolus and evaluated at the bedside with physical therapy.

The goal of physical therapy is to help the patient ambulate safely using assistive devices while maintaining the total hip precautions. In the days following surgery, the goal of the therapist is to increase the range of motion and access the strength of the hip muscles in all planes, which are flexion-extension, abduction-adduction, and internal and external rotation.

Precautions for the joint replacement patient are:

* don't bend more than 90 degrees

* don't cross the legs in either the seated or supine position

* don't twist or turn hips

* don't lift knees above the hips.

The therapist may then develop a customized treatment program to:

* educate patients on safety and hip precautions for ADLs

* improve the ability to perform ADLs

* increase upper body strength for improved transfers, bed mobility, and functional mobility with an assistive device

* increase endurance and the ability to sustain activity for periods of time to complete ADLs

* provide adaptive equipment recommendations and training to help patients bathe and dress themselves according to the hip precautions

* make recommendations and educate patients on how to use equipment for safe transfers while in the hospital and at home. OR

How arthritis and osteonecrosis take a toll on joints

The most common form of arthritis, osteoarthritis, affects 30 million people in the United States. Pain occurs because the articular cartilage on the femoral head and inside the acetabulum wears thin, letting the bones rub together.

Rheumatoid arthritis is a chronic, inflammatory autoimmune disease. The body responds to an unknown trigger. Antigen- antibody complexes deposit in the synovium and cause an inflammatory response, including warmth, pain, redness, and swelling. Rheumatoid arthritis attacks and destroys the soft tissue, bone, and cartilage in affected joints.

Osteonecrosis or avascular necrosis occurs when the blood supply to the femoral head is interrupted or destroyed. Causes include trauma such as dislocation or fracture, some glandular diseases, alcohol abuse, and long-term corticosteroid treatment.

Conservative treatments for osteoarthritis and rheumatoid arthritis involve medications, rest, and physical therapy before total joint arthroplasty is considered. Osteonecrosis of the femoral head may respond to early surgical decompression and bone grafting to encourage growth of new blood vessels to the femoral head.

Adapted from: Hohler SE. Looking into minimally invasive total hip arthroplasty. Nursing. 2005;35(6):54-57.

Managing blood loss

Every effort is taken to make sure that patients are hemodynamically stable. Surgeons also attempt to reduce blood loss during hip replacement surgery. The surgeon may use instruments such as ultrasonic cutting and coagulating scalpels or an instrument that seals off blood vessels in soft tissue and bone. The use of a specialized auto transfusion system, which washes the blood cells, has reduced the number of transfusions used in joint replacement surgery.

The Blood Management and Conservation Program was established to accommodate Jehovah's Witness patients who refused to use blood and blood products. This program has spread beyond the Jehovah's Witness community, and now nurses can help patients with low hemoglobin better prepare for surgery by informing them about resources available to reduce the need for blood transfusions, offering education on foods high in iron and taking iron supplements, and receiving injections of medications that stimulate bone marrow production of red blood cells.

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