Common impairments following lower extremity joint arthroplasty include weakness in the affected extremity, limited range of motion, reduced endurance, and impaired balance. Activity limitations include difficulty performing activities of daily living such as bathing, dressing, grooming, transfers from different surfaces, and ambulation on different terrains and stairs. Participation restrictions include inability to drive, return to work, and high-level recreational activities such as jogging and bicycle riding.

To ensure a complete recovery, it is important to understand the psychosocial impact on the physical recovery of the patient. The ability to function within the patient’s social environment may become very difficult after surgery. The patient’s role within his or her family prior to the surgery may need to be altered during the recovery period. The patient may experience a low level of self-esteem if he or she cannot return to his or her prior role (e.g., cooking and cleaning the home, primary financial provider for the family). It is important to identify for the patient a network of family and friends who can assist with the physical limitations and also have a positive impact on their mental health.

Some patients are highly motivated and push themselves in therapy so they can quickly resume their previous level of functioning; however, it is critical that this type of patient be educated about the disadvantages of pushing therapy too quickly. The other type of patient is one who is reluctant to participate in therapy and needs to be coaxed into undergoing the rehabilitative program. It is always important to remember that some patients may have a hard time adjusting to the physical limitations and dependency post surgery and can become clinically depressed. Patients will need to be counseled on lifestyle changes that will improve their overall health as well as the wear and tear on their joints. Connecting patients with a nutritionist or other weight loss programs will help them attain their appropriate weight for height goals and will ultimately help the patient get on the road to a healthier pain-free life. Along with a healthier lifestyle the benefits of exercise, stretching, and physical therapy go further into prevention of postoperative contractures.

Patients who have undergone total joint arthroplasty of the lower extremity will have limited ability to return to work for several weeks post surgery. Some will have to take an extended medical leave from work. Physical therapy, occupational therapy, and vocational therapy are all essential components for a quick recovery. Regaining the ability to walk without assistance on flat surfaces and stairs, increasing the range of motion in the affected joint, practicing household chores, and driving are all components of therapy to assist in the patient’s return to previous functional status.

Ideally, the rehabilitation program for the lower extremity joint arthroplasty patient should begin prior to surgery. During this period the patient is educated about the surgery and postoperative rehabilitation and care. Exercise programs to improve overall endurance, range of motion, and strength in key muscle groups of the lower and upper extremities would be very beneficial.

Following surgery, the rehabilitation program begins on the first day post procedure. For hip arthroplasty patients, restrictions such as not crossing the legs or bending from the waist more than 90° are important to minimize the risk of hip dislocation (4). Therapies are guided by these restrictions. Physical therapists work with the patient on improving the range of motion of the lower extremities within restriction parameters and strength training of key muscle groups such as the hip flexors, abductors, and extensors; knee flexors and extensors; ankle dorsi and plantar flexors. Modalities such as cold therapy can be used to reduce pain. Functional activities such as bed mobility, transfers, and ambulation on different terrains and stairs are also performed. The patient is also provided with a home exercise program. Occupational therapists educate the patients on performing specific activities of daily living such as bathing, dressing, and toileting within the restrictions of their range of motion. In addition, they work with the patient on strengthening key muscle groups of the upper extremities and trunk that are essential for performing these types of activities and also provide the patient with appropriate assistive devices to assist them in these activities. In the inpatient rehabilitation setting, the patient may also require the services of other rehabilitation team members such as rehabilitation nurses, psychologists, social workers, and vocational counselors.

In order for the patient to fully benefit from the postoperative rehabilitation, he or she needs to have the pain well controlled. Joint arthroplasty can be a very painful procedure and post surgery it is important for patients to actively move painful joints. The pain can be controlled using modalities such as cold therapy and medications such as acetaminophen and opioid medications. The timing of medications is important so that the maximal analgesic benefit from the medications can coincide with the time the patient is actively getting rehabilitation.

Following the initial rehabilitation period, the patient post total joint arthroplasty typically continues with rehabilitation in an outpatient setting. Here the emphasis is on continuation of exercises to strengthen muscles in the affected extremity, improve flexibility, increase ambulation distance, and continue progress toward independence in activities of daily living. Most patients return to their normal activities within 3 to 6 months post surgery and are encouraged to maintain an active lifestyle thereafter (5). Issues such as return to work and resumption of driving are based on patient’s level of function and remain barriers that would impede a safe return.

It is important to be aware of injuries that may occur after total joint arthroplasty. Complications and risks include but are not limited to venous thromboembolism in the lower extremities, dislocations, falls, fractures, infections, and pressure ulcers.

Venous Thromboembolism

When a patient undergoes a hip or knee arthroplasty, he or she is at an increased risk for the development of venous thromboembolism. Studies have shown rates of thrombosis after joint replacement have been as high as 31% even while on pharmacological anticoagulation. One study showed thrombosis in 16% of THA patients and 31% after TKA. It has been recommended to use a combination of pharmacological anticoagulation with mechanical anticoagulation, such as intermittent pneumatic compression (ICP) (6). It is important to educate the patient on the signs and symptoms of blood clots such as leg swelling, redness, and pain. It is essential to discuss all the medications with the patient and help him or her understand the importance of blood thinners.

There are many available options for doctors and patients to consider for venous thromboembolism prophylaxis such as warfarin, low-molecular-weight heparin, aspirin, rivaroxaban, fondaparinux, and compression devices for the lower extremities. It is important to not only understand the prophylaxis benefits of these drugs but also consider the bleeding risks that come with some of these therapies (7). Each drug has its negatives and positives that need to be considered and discussed with the patient. For example, warfarin is a low-cost anticoagulant that has shown efficacy in prevention of venous thromboembolisms and has lower rates of bleeding, but this benefit is only with compliance of the INR between 2 and 3 (7). Studies have shown that up to 83% of total hip and knee arthroplasty patients are nontherapeutic on postoperative day 4 (7). This shows that warfarin is an effective medication but is limited by the ability to control the medication within the therapeutic window. Before placing a patient on anticoagulants it is important to consider all of the risk factors and choose the medication that is best suited for the patient.

Hip Dislocation

Developing a hip dislocation is a potential complication following THA. Hip adduction or flexion greater than 90° can cause the newly implanted hip to dislocate. To prevent dislocations, hip precautions are prescribed: (a) no hip adduction across the mid-line, (b) no hip flexion greater than 90°. Placing an abduction pillow between the patient’s legs can be of benefit. If a dislocation occurs, the patient may be fitted for a brace to maintain the correct position.

Hip Fracture

A fracture of the hip is another complication post surgery. Healthy areas of the hip may sustain small fractures, which can either heal on their own or require bone grafts to fix. To prevent fractures post THA, bisphosphonates can be used to decrease the risk through primary prevention and secondary prevention by 44% and 50% (8).

Infections

Infections are a complication of any surgery at the incision site. It is important to do proper wound care for the incision as well as be able to recognize whether the wound is infected early so antibiotics can be started appropriately. Removing a urinary catheter on postoperative day 1 can help reduce the predisposition for getting a urinary tract infection. By administering antibiotics before and after the surgery, infections can be prevented. Preoperative screening for nasal bacterial colonization several weeks prior to surgery can help detect potential sources that predispose prosthetics to infections (9).

Pressure Ulcers

Patients who are immobilized in a hospital bed have an increased likelihood of developing pressure ulcers. It is important to use devices that will alleviate pressure from dependent areas and rotate the patient when appropriate. It is also important to monitor any skin breakdown that will potentially lead to ulcer development. It is also important to monitor both the operated side and the nonoperated side. Areas such as the sacrum and heels are especially prone to developing pressure ulcers, so it is particularly important to monitor these areas for skin breakdown.

Falls

Injuries associated with falls can be avoided if the patient uses his or her walker or cane appropriately and waits until he or she has assistance. This is sometimes hard for a previously independent patient to understand. Along with the hip or knee being unstable to fully bear weight, the patient may also have postural hypotension from lying in bed for a long period of time. Educating the patient about the risk of falls and providing assistance can prevent these injuries from occurring in the inpatient setting. Environmental modifications such as lowering the patient’s bed and ensuring that the brakes are on, eliminating clutter around the bedside, and educating the patient to use a call bell are all important to minimize risk of falls. Educating the patient on reoccurrence of falls if they do happen is just as important as preventing falls in the first place.

Contractures

Hip or knee flexion contractures can occur following lower joint arthroplasty. This is a significant complication since it can limit functional use of the limb post surgery. All efforts should be made to minimize contractures. This includes adequate pain control during rehabilitation so that the patient can perform range of motion and strengthening exercises and use of braces as necessary. Timely and effective communication with the orthopedist and treating therapists is essential.

Footdrop

Footdrop is a possible complication following joint arthroplasty of the hip or knee. Possible etiologies include injury to the sciatic or common peroneal nerve. The incidence of footdrop is fairly low with Weber et al. reporting a 0.07% incidence in 2,012 hip arthroplasties (10). Occasionally footdrop may occur secondary to acquired spinal stenosis after joint arthroplasty. Sometimes this can occur up to 9 months after surgery (11).

MEDICAL KNOWLEDGE

GOALS

Demonstrate knowledge of established and evolving biomedical, clinical epidemiological, and sociobehavioral sciences pertaining to hip and knee arthroplasty, as well as the application of this knowledge to guide holistic patient care.

OBJECTIVES

1.  Discuss the following as they relate to hip and knee joint arthroplasty: (a) epidemiology, (b) indications and contraindications, (c) surgical procedure, and (d) rehabilitation.

EPIDEMIOLOGY

Knee and hip joint arthroplasty surgeries have increased over the past decade in North America (12). From 1991 to 2010 TKAs alone increased 162%, with an annual procedure rate of about 600,000 procedures (13). Kurtz et al. reported on the prevalence of primary and revision TKA and THA in the United States using data from the National Hospital Discharge Survey and U.S. Census from 1990 to 2002 and found 50% increase in the rate of primary THAs. Rates for primary TKAs almost tripled. Rates for revisions of TKAs and THAs also increased. The authors concluded that in the future the rates for these procedures will continue to increase (14). Mehrotra et al. reviewed the data from hospital discharges in Wisconsin from 1990 to 2000 and reported that the increase in the number of TKAs performed was greatest in the 40- to 49-year-old population. The cost associated with these procedures increased 109%, with Medicare receiving the highest proportion of charges (15). The finding that joint arthroplasty is being performed in younger populations has been reported elsewhere in the literature as well (16). Racial disparities between different groups have also been described, with fewer rates for TKAs being performed for African Americans, Hispanics, Chinese, and Filipino compared to Caucasians (12,17).

INDICATIONS AND CONTRAINDICATIONS

The primary indication for THA and TKA is to reduce pain and disability in the knee and hip, respectively, that have not responded well to conservative management. The cause of the pain and disability can be attributed to irreversible damage to the bone and cartilage in the joint. Some of the etiologies of joint disease requiring surgery include osteoarthritis, rheumatoid arthritis, avascular necrosis, trauma, and childhood joint disease (18).

Some relative contraindications to surgery include individuals who are (a) not good surgical candidates, (b) nonambulatory, and (c) have osteomyelitis (19). In the past older populations were not deemed good candidates for lower limb joint replacement surgery due to factors and comorbidities associated with advanced age; however, studies have shown that despite a long rehabilitation, this group of individuals can still have very good long-term outcomes (20).

SURGICAL TECHNIQUE

Total Hip Arthroplasty

This surgical procedure is performed in an operating room by an orthopedic surgeon and can take up to 3 hours. It can be performed with the patient under spinal/epidural or general anesthesia. The surgeons generally approach the surgery by making a single incision in either the posterior or lateral portion of the hip. A recent review of the literature did not find significant differences between these two approaches; however, it mentioned that there may be an increased risk of nerve injury utilizing a direct lateral approach (21). The procedure consists of removing the damaged femoral head and cartilage using a specialized tool called a reamer. The reamer scrapes away damaged tissue to prepare the socket for the new hip replacement. Once the socket is prepared, the acetabular component of the hip replacement (called the shell or cup) is placed into the acetabulum. This “cup” is fit to be slightly bigger than the cleared acetabular space to allow for a tight fit between the hardware and the pelvis. The femur is then prepared and a femoral stem is placed into the bone. The femoral stem can be held with or without the use of cement. Once the stem is in place, the metal ball is fit tightly into it. Once the ball is on the stem, the hip can be reduced and the hip joint is intact and in the proper location. The incision is closed and proper dressing placed.

Total Knee Arthroplasty Surgery

This surgical procedure is performed in an operating room by an orthopedic surgeon and can take up to 2 hours. In the initial step, the diseased distal end of the femur and proximal end of the tibia are removed to ensure a good surface for the new joint. In the second step, the metal implants used to recreate the joint are “press fit” or cemented into the bone for a secure placement (22). Once the implants have been placed, some surgeons resurface the underside of the patella with a plastic button. A spacer is then inserted between the two metal components to allow for a smooth articulating surface. A review of the literature reported a greater risk of future aseptic loosening for cemented fixation vs. cementless fixation (23).

REHABILITATION

Early rehabilitation after surgery can help improve outcomes such as achievement of functional milestones, fewer postoperative complications, and shorter hospital stay (24).

Cryotherapy has been used following TKA; however, a recent review of the literature found a low level of quality for the evidence of its effect on postoperative pain, range of motion, and length of stay (25).