Osteoarthritis: Eliminating Pain and Restoring Function—An Orthopedic Perspective
Osteoarthritis, particularly of the hip and knee, is a pervasive source of disability in the United States. It is estimated to involve over 70 million Americans, or 1 out of 3 adults in our population.1 Arthritis accounts for 17% of the diagnoses in U.S. residents currently on permanent long-term disability. The Centers for Disease Control and Prevention estimates that by the year 2030, approximately 41 million Americans over the age of 65 years will have severe arthritis.2
The practical implication of these overwhelming numbers is equally significant. A survey in 2005 by the National Council on Aging showed the effects of arthritis on activities of daily living in geriatric patients. When asked about lifestyle perceptions, 64% of respondents categorized themselves as very or extremely active prior to the onset of arthritis, with the number dropping to 13% after onset. Significant weight gain was reported in 56% and loss of normal sleep patterns was seen in 59% of the study group. Long car rides were avoided by 35% of people, while one-third of participants were no longer able to shop for food and essentials.3
The etiology of osteoarthritis, which was frequently relegated to the term primary osteoarthritis in the past, indicating an unknown causation, is rapidly evolving to indicate specific etiologic factors. We know, for example, that many structural abnormalities, both those that occur intrauterine (ie, hip dysplasia) and those of a developmental nature (ie, slipped epiphyses, Perthes disease, femoroacetabular impingement), will manifest significant arthritic involvement after the fifth decade of life. In addition, and especially pertinent to the knee, trauma and injuries sustained in the early years, including meniscal tears, ligament injuries, and structural deviations such as significant varus and valgus malalignments (knock-knee and bowleg deformities), will appear as osteoarthritis in later years. A strong genetic predisposition is clearly seen in families, although the precise Mendelian pathways have yet to be clarified. Obesity is also a cause of the degeneration of weight-bearing joints.4 Aging, which seems intuitively obvious as an etiologic factor in the development of arthritis, has been further explained by a decrease in collagen and collagenase activity in the aging hip joint.5 Muscle weakness and decreased muscle mass, commonly seen as a part of the aging process, has been implicated in progressive arthritis in the weight-bearing joints.6
What are the signs and symptoms that present the patient to his or her primary care provider? Some are obvious, but many can overlap with a variety of other nonorthopedic etiologies. In osteoarthritis of the knee, the presentation is usually overt. Knee pain associated with swelling, warmth, stiffness, and loss of knee motion are all usually present to a variable degree, depending upon the severity of the arthritic process. Hip osteoarthritis, however, can be far more confusing. Pain may be localized in any of the following sites: the groin; the buttock; the anterior thigh; and even in the knee. The knee pain, in fact, may exist even without hip pain at the beginning of the hip deterioration. It is for this reason that the orthopedic exam in a patient presenting with knee complaints must always include a hip exam as well. Groin pain obviously leads to confusion in patients with no prior history of arthritis. The pain may signal a gastrointestinal (GI) or genitourinary issue, a hernia, a gynecological problem, or other nonorthopedic etiologies. A thorough history will uncover a functional deficit in most orthopedic causes. Loss of hip motion most commonly will translate to a patient’s complaint of difficulty with activities such as putting on socks and shoes, tying shoelaces, or cutting his or her toenails. Ambulatory deterioration comes later in the process but must always be distinguished from ambulatory issues caused by peripheral vascular issues and spinal deterioration, most often spinal stenosis.
Plain x-rays are usually the gold standard for making the diagnosis. Rarely are magnetic resonance imaging scans needed; in fact, they are most often the source of confusion, especially in cases of knee arthritis, when meniscus tears will manifest as part of the degenerative process. This finding misleads many clinicians to assume that arthroscopic intervention for the meniscus tears will improve knee function when in reality it most often worsens the symptoms. Blood work is only of value in a patient who presents with polyarticular involvement, as it can rule out inflammatory arthritides. It is of importance that the films be ordered with the patient standing, as supine films for knee arthritis may underestimate the degree of joint space narrowing.
In the most common presentation of osteoarthritis, the patient’s symptoms center on one joint, and there is a relatively long and slow progression. However, we are faced with an ever-increasing patient group who presents with polyarticular involvement, a more acute presentation that may be associated with systemic and other symptoms. These patients may or may not give a history of residence or recent travel to an endemic area for ticks, and they are best served by referral for a formal rheumatologic consultation to rule out an inflammatory etiology for their complaints.
Initial treatment of arthritis of the hip and knee focuses on nonsurgical management. It is only when all of the following modalities fail that surgical considerations should be entertained. Activity modification is usually self-imposed by the patient. We see patients who are still involved in many athletic activities including golf and tennis well into their eighth decade. While athletic activities may increase the pain and stiffness of arthritis, their benefit to patients’ cardiovascular physiology and to their mental health probably far outweigh the downsides of the pain and stiffness they may augment.7 Much is written about weight loss in patients with body mass indices of over 30.8,9 The problem, however, is that these patients are unable to engage in an exercise regimen by the nature of their disease. Therefore, it becomes impossible to alter their weight with caloric restriction alone. The value of physical therapy is also problematic. On the one hand, the loss of muscle power around the hip and knee that is always seen in the patient with arthritis worsens his or her symptoms, as does the loss of motion of these joints. On the other hand, the exercises needed to improve their power and range frequently accentuate the pain from the arthritic joint. A trial of physiotherapy with this understanding is certainly of value, and has been reported to successfully decrease pain and stiffness in many patients.10,11 As arthritis progresses, motion decreases, and power diminishes, the use of weight-relieving devices such as a cane or walker is invaluable. Not only do they diminish pain, but they also improve stability, thereby lessening the chance of a mechanical fall.12 Unfortunately, many patients look upon the use of such devices with a jaundiced eye, feeling that they belong to a more “elderly” individual than they perceive themselves to be.
Appropriate use of pharmacological interventions can have a profound effect on the symptoms of osteoarthritis in the early stages of the disease.13 Analgesics of mild degree, such as acetaminophen, may decrease pain. Over-the-counter and prescription nonsteroidal anti-inflammatory drugs (NSAIDs) may play a key role in restoring function and increasing activities of daily living, and when tolerated without GI issues may be the source of benefit for several years. There are, however, no long-term prospective studies that document the benefit of NSAIDs versus simple analgesics versus over-the-counter medications.14 In light of the fact that NSAIDs do not change the natural history of the disease but do increase the likelihood of gastropathy, as well as the potential cardiac issues that led to the removal of rofecoxib from the marketplace, the use of NSAIDs should be reserved for short periods of symptomatic relief and clinicians should be circumspect in relying upon them as definite long-term solutions to osteoarthritis management. Alternatively, many patients can be treated using nonselective NSAIDs along with a gastroprotective agent. Many patients inquire about glucosamine/chondroitin preparations, which are advertised to the lay public as having a “cartilage restorative” benefit. It has recently been shown that these preparations provide no significant benefit as part of the arthritis treatment armamentarium.15 The use of viscosupplementation preparations (ie, hylan G-F 20) has emerged as an important addition to our armamentarium. Single injections of these products are shown to give excellent short-term relief in the knee joint. Their duration of action and the degree of relief, however, are somewhat unpredictable, but many patients are managed with 1 or 2 injections per year.16 Use of these products is currently off label in any joint other than the knee, but may prove beneficial in the hip joint as well, understanding that the hip injection requires the use of a fluoroscopically controlled intervention. Corticosteroids, when used judiciously, are similarly effective in diminishing pain, swelling, and stiffness.17
When all nonsurgical options are no longer efficacious, then referral for an orthopedic consultation would be indicated and surgical intervention should be considered. There are several important issues with regard to the timing of surgery that are specific to the geriatric population. It has been documented repeatedly by the Swedish Hip Registry that the postsurgical benefit of joint replacement surgery is related to the presurgical level of function.18 Range of motion after hip and knee replacement is most closely correlated to presurgical range of motion. Practically speaking, a patient who is becoming progressively more sedentary should never be allowed to deteriorate to the level of a wheel chair existence, even for a short period of time. Flexion contractures of the hip and knee will set in rapidly, will be difficult to correct even surgically, and will profoundly affect the level of function after surgery. Further, the deterioration of a patient’s cardiac and pulmonary function as a result of a progressively sedentary lifestyle will also adversely impact his or her ultimate outcome.
There are several perioperative issues that must be considered in the patient preparing for hip or knee replacement. All patients undergoing joint replacement surgery should be advised that their procedures will be performed under regional anesthesia, either spinal, epidural, or combined spinal/epidural. The benefits are manifold, including lower intraoperative blood loss, diminished postsurgical thromboembolic issues, and better postsurgical pain management.19 The use of allogenic blood has been implicated in higher postoperative infection rates; thus, when blood loss is anticipated, consideration may be given to autologous blood donation.20 As regional anesthesia is the gold standard for joint replacement surgery, all medications that affect clotting must be discontinued prior to surgery so as not to compromise the use of neuraxial anesthesia. Current anesthesia guidelines mandate discontinuation of aspirin and NSAIDs 10 days prior, clopidogrel 7 days prior, and warfarin stopped sufficiently to bring the international normalized ratio below 1.2.21
Ambulation is instituted the morning after replacement surgery. It is mandatory that all patients receive some form of antithromboembolic prophylaxis, whether chemoprophylaxis, mechanical prophylaxis, or a combination of both.22 Similarly, prophylactic antibiotics are instituted with the first dose within 1 hour of onset of surgery, but discontinued after 24 hours. Depending upon the patient’s preoperative level of function, home situation, and comorbidities, most patients will be able to achieve a sufficient level of independence to be discharged from the hospital with home physical therapy within 4 days. For those who have not achieved that level of function, acute or subacute rehabilitation can be instituted.
The efficacy of hip and knee replacement in achieving their intended goals of eliminating pain and restoring the patient to an ambulatory existence in the community have been well documented in outcome studies in the orthopedic literature. Changes in surgical techniques that minimize blood loss and the use of regional anesthetic techniques have diminished the physiologic stress on the elderly patient as well as the patient with multiple comorbidities, enabling all age groups to benefit from hip and knee reconstructive surgery.
The appropriate management of the geriatric patient with hip and knee arthritis as well as the timely intervention of joint replacement surgery can ensure that a patient’s function will be maintained, pain appropriately controlled, and lifestyle continued.
Dr. Strauss is a consultant for Stryker. The other authors report no relevant financial relationships.
Mr. Wesley Bronson is a third-year medical student, Dr. Strauss is Associate Professor of Orthopaedics and Associate Professor of Geriatrics and Palliative Medicine, and Dr. Michael Bronson is Chief of Joint Replacement Surgery and Associate Professor of Orthopaedic Surgery, Mount Sinai School of Medicine, New York, NY.