The objectives of OA management are to lessen painful symptoms and improve function and quality of life. The scope of OA management has appropriately broadened beyond medicinal agents to include physical and rehabilitative and other interventions. Primary-care practitioners can set in motion numerous services (e.g., rheumatology, physiatry, physical or occupational therapy, psychology, nutrition, social work, and orthopedic surgery) in pursuit of these objectives. Currently used management options are summarized in Table 116-2.
The effectiveness of OA management is highly dependent on patient compliance. Therefore, patient education should be considered the initial required element in OA management. Educational groups or classes provide an efficient and social vehicle to convey general information pertaining to OA and management strategies. Topics might include warning signs of medication toxicity, exercise, weight management, stress management, sleep hygiene, and general healthy living. Participants in self-management groups report less pain and reliance on nonsteroidal anti-inflammatory agents. Additional benefits of participation in these programs include boosting self-efficacy, increased physical activity, and lessening the frequency of arthritis-related physician visits. However, program participation does not obviate the need for individualized patient education in matters of medication compliance and drug toxicity monitoring.
Weight loss in obese individuals with OA of the knee can reduce painful symptoms as well as slow disease progression and is, therefore, recommended for all patients who are overweight. In many cases, a structured weight management program with counseling may be required. Although a 10% reduction in weight is considered a reasonable objective, this should be achieved by combined exercise with dietary modification in older adult patients as a result of the additional benefits gained through muscle strengthening.
Several studies have provided convincing evidence that resistive and aerobic exercise training is an effective means of reducing pain severity and disability in older adults with knee OA. General steps for composing an exercise prescription begin with reviewing absolute and relative contraindications and setting realistic objectives. Additional specifics are depicted in Figure 116-4 and include selecting the form of exercise most appropriate to the patient's current functional and health status, and finally to provide the details of intensity, duration, and frequency. Patients should be advised to watch for signs of excessive joint strain, including pain during activity, pain lasting more than 1 to 2 hours after exercise, swelling, fatigue, and weakness.
Prescribed exercise begins with selecting the form of exercise most appropriate to the patient's current functional and health status and finally to provide the details of intensity, duration, and frequency. Exercise precautions should be reviewed.
Mobilization exercises (i.e., stretching and flexibility training) are typically the first steps in restoring function and focus on relieving stiffness and increase joint mobility by increasing length and elasticity in muscles and periarticular tissues. Isometric exercises should be introduced early, given benefits of restoring muscle strength and joint stabilization without increasing pain. Straight leg raises, wall sits, and isometric leg presses are some examples of isometric quadriceps-strengthening exercises. Strengthening the quadriceps may realign and stabilize joints. Isotonic exercises can be introduced later to strengthen muscles as joints move. Squats, wall slides, and leg presses are some examples of isotonic exercise that strengthen both quadriceps and hamstring muscles concurrently. Aquatic exercise provides resistance exercise training while also unloading up to 50% to 60% of body weight. Finally, aerobic exercise improves fitness, exercise tolerance, and endurance. Walking and low-impact and aquatic aerobic programs improve overall general fitness and coordination. Patients with weight-bearing OA (knee and hip) should engage in strenuous activities cautiously. Some weight-bearing exercises such as stair climbing and heavy lifting (i.e., loads greater than 10% of body weight) may significantly increase loading on weight-bearing joints, as do speed walking and running.
Neuromuscular electrical stimulation delivers low-voltage electrical impulses through surface electrodes placed over motor points of the targeted muscle. Electrical stimulation induces muscle contraction. Neuromuscular electrical stimulation has been used to increase quadriceps muscle strength and lessen pain in older adults with disabilities with knee OA and may be an acceptable alternative for patients who are unable to participate in exercise owing to severe pain or contraindications.
Therapeutic ultrasound is one of the most widely prescribed modalities for pain and loss of function caused by OA. Ultrasound uses high-frequency (0.8–1.0 MHz) sound waves to reduce painful symptoms by pulsed delivery for acute pain and inflammation or by continuous delivery for patients with chronic symptoms that have resulted in joint limitations.
Cryotherapy and Thermotherapy
Cold and heat are useful adjuncts for the treatment of OA and may decrease both pain and muscle spasms. Cold reduces the inflammation of arthritis, minimizes muscle spasm, and decreases the sensation of pain. Patients should limit use of ice or cold packs to 20 minutes or when the area becomes numb. Cautious use of heat can reduce pain and muscle spasm but should be limited to 20-minute intervals. Contrast therapy, which alternates between hot and cold treatment modalities, provides additional therapeutic benefits compared to either alone.
Acupuncture has been included as a potentially useful adjunctive therapy in a comprehensive disease management program for OA. Transcutaneous electrical nerve stimulation delivers acupuncture-like stimulation in random order and is one of the modern changes to classical acupuncture.
Rubbing a painful joint is almost a reflex action for some clients. Massage is theorized to reduce pain by enhancing endorphin release. Massage relaxes muscle groups and may be a useful adjunct for patients with anxiety and depression.
Specific orthoses designed to reduce medial knee pain by unloading the medial compartment of the knee include a valgus unloader brace and a lateral wedge insole. Lateral wedge insoles of 5 and 10 degrees lateral significantly reduced knee varus torque during ambulation by 6% and 8%, respectively. A simpler change to a well-designed running shoe may also lessen pain and damage by decreasing the impact transmitted during ambulation.
Individuals with knee OA may experience knee instability, which can be described as buckling, shifting, or giving way of the knee. Neoprene braces are often requested by patients but unlikely to provide the required structural support, since multiple factors such as lower muscle strength and neuromuscular control and capsuloligamentous laxity likely contribute. However, neoprene braces may alleviate patellofemoral symptoms by improving patellar tracking and provide a greater sense of joint stability by improving joint proprioception.
A cane that is properly fitted to the level of the greater trochanter of the hip and held in the hand opposite to the affected knee or hip can reduce joint loading and symptoms significantly. Patients with advanced hand OA may require task modification or use of meal preparation devices, and hip OA may require additional devices to dress independently.
Symptom-Directed Medicinal Therapy
Alleviation of painful symptoms constitutes the primary focus of prescribed and over-the-counter medicinal management of OA. In general, treatments should use the least toxic and least expensive medications first. Furthermore, since there is no single best medication for any given patient, selection of specific agents should be based on each patient's symptom severity and weighed against potential adverse events. Finally, it is important to recognize the complexity of treating painful symptoms in older adult patients who are more likely to endure comorbid medical conditions and multiple medications.
Topical agents have a role in the treatment of OA. Capsaicin, derived from capsicum, the common pepper plant, is known to be effective in management of OA of the hands when applied two to four times daily. Care should be taken to avoid the inadvertent application of capsaicin in the eyes and other mucous membranes. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) may provide short-term relief of painful symptoms of knee OA. Although generally well tolerated, use of other topical analgesic agents (e.g., nonprescription formulations of menthol- and salicylate-based preparations) has not been proven more effective than placebo.
Acetaminophen remains the first-line drug of choice for OA management. Acetaminophen should be used at a dose not to exceed 1 g four-times daily (maximum U.S. daily dose of 4 g) and is well tolerated. Despite some evidence of exacerbated renal insufficiency, it is a safer drug than are NSAIDs for patients with renal impairment. Acetaminophen should be used cautiously in patients with impaired liver function and should not be taken with alcohol.
Tramadol is an effective analgesic in management of OA symptoms. A starting dose of 25 mg daily for 3 days can be escalated slowly to a maximum dose thereafter to achieve the desired analgesia. Tramadol also has NSAID-sparing effects. Potential adverse effects include nausea and drowsiness. Seizures and allergic reactions have also been reported at higher doses. Although tramadol is not a controlled substance, it can be abused by patients with opioid dependence.
Non-steroidal Anti-inflammatory Drugs
NSAIDs are the most commonly prescribed agents for treatment of both pain and inflammation in OA and appear to be more effective in relieving moderate-to-severe pain than acetaminophen. Although all NSAIDS inhibit cyclooxygenase enzymes, patient responses to specific agents may vary considerably. Patients vary in their benefit and adverse reactions to various NSAIDs. Difference in half-lives of the NSAIDs may influence patient adherence and dosing. Despite their efficacy, NSAIDs should be prescribed with caution. Analgesia can often be achieved at low doses. Thus, treatment should begin with the lowest dose and increased incrementally to identify the lowest effective dose for each patient. Additionally, NSAIDs can be used intermittently and in combination with other analgesics.
Patients using NSAIDs should be monitored for gastrointestinal (GI) symptoms of dyspepsia, peptic ulcer disease, gastritis, and GI bleeding; however, GI bleeding may occur in the absence of prior symptoms. In patients at risk of GI events, prophylaxis is highly recommended using one of three strategies. Once-daily proton pump inhibitor therapy decreases dyspepsia and also effectively decreases the development of NSAID-associated ulcers and recurrent NSAID-related ulcer complications. Prophylaxis is also indicated for older adult patients taking low-dose aspirin who are at higher risk of GI toxicity. A second strategy to reduce GI events is cotreatment with misoprostol. Although misoprostol also decreases NSAID-induced ulcers and GI complications, its effectiveness depends on frequent dosing that in itself can cause diarrhea and dyspepsia. A third option for patients at high risk is to add a proton pump inhibitor. Cotreatment with H2 blockers and sucralfate may reduce GI symptoms but does not reduce the risk of ulcers or serious GI complications.
Cyclooxygenase (COX)-2 inhibitors represent the third strategy for reducing NSAID-related GI complications. COX-2 inhibitors (celecoxib, rofecoxib, valdecoxib, etc.) can effectively relieve painful OA symptoms, with less risk of GI symptoms and serious GI adverse events when compared to nonselective NSAIDs. However, the potential benefits of COX-2 use should be weighed against the potential risks. First, data showing an increased risk of acute cardiovascular events in association with the use of selective COX-2 inhibitors have resulted in the removal of two of the three FDA-approved agents from the market (rofecoxib and valdecoxib) and a considerably more cautious approach to the use of the remaining agent (celecoxib). Although cotreatment with aspirin may be considered, concurrent use of low-dose aspirin may compromise the protective advantage of COX-2 selectivity in patients who have already experienced a GI bleed. Therefore, addition of a proton pump inhibitor may be required in patients at high risk. Finally, COX-2 selective agents are as likely as nonselective NSAIDS to reduce kidney function, particularly in older adults with renal compromise. Finally, coagulation parameters should be carefully monitored in patients who add any medication to their anticoagulants because of potential drug interactions. Thus, the risks and benefits of COX-2 selective antagonists must be carefully considered in each patient.
Numerous nutriceutical products are advertised to reduce painful symptoms and to “promote joint health” with limited well-controlled studies to validate their efficacy. Oral glucosamine and chondroitin sulfate are popular nutritional supplements thought to relieve pain and limit OA progression. Two randomized placebo-controlled trials showed that glucosamine treatment slows rate of joint space narrowing for more than 3 years and chondroitin sulfate treatment for more than 2 years. Interestingly, some studies demonstrating structure modification do not have concomitant symptom improvement, with no consistent improvement in OA symptoms observed with glucosamine or chondroitin treatment across studies. Fortunately, glucosamine and chondroitin sulfate are relatively well tolerated. Earlier concerns of hyperglycemia, exacerbated diabetes, and possible effects of chondroitin effects on coagulation parameters have not been seen in recent studies. Thus, at present, a 3-month trial is likely safe but should be discontinued if symptoms do not abate. Other products such as S-adenosylmethionine or methylsulfonylmethane, shark cartilage, and others remain commercially available and successfully marketed despite the absence of scientific support for their use in the treatment of painful OA.
Diacerein (50 mg twice daily) is an interesting compound that exerts anti-inflammatory effects by inhibiting interleukin-1 and collagenase production, with additional effects on neutrophil chemotaxis macrophage migration and phagocytosis. Diacerein does not alter renal or platelet cyclooxygenase activity and may, therefore, be tolerated by patients with prostaglandin-dependent renal function.
Narcotic analgesics can be effectively prescribed in management of OA pain. Long-acting preparations of oxycodone can be considered for patients with persistent moderate-to-severe pain. For patients with persistent symptoms despite simple analgesics, codeine or propoxyphene can be prescribed. Short-term studies support the use of slow-release formulations of narcotics administered in low doses, such as oxycodone SR 10 mg, for patients with moderate-to-severe OA of the knee in whom pain is inadequately controlled by acetaminophen or NSAIDs alone. Improvements in pain and quality of sleep were comparable for short- versus long-acting narcotic preparations, with comparatively fewer GI side effects. These agents may be particularly useful for chronic management of patients with severe knee or hip OA in patients who are not surgical candidates owing to comorbid cardiac or pulmonary illness.
Structure-Modifying Medicinal Agents
Although definitive structure and disease-modifying therapies are not yet available for OA, several promising studies have been conducted, which provide hope that such therapy is within reach. Diacerhein has been proposed as a slow-acting, symptom-modifying, and perhaps disease-structure-modifying drug for OA. Doxycycline is of interest for its metalloproteinase-inhibiting activity and ability to limit joint space narrowing in obese women, but it does not appear to prevent disease development or improve symptomatic outcomes. Risedronate, a bisphosphonate indicated for treatment of osteoporosis, has recently been shown to reduce markers of cartilage degradation and bone resorption. Other agents of interest as potential OA structure modifiers include antagonists of interleukin-1 and inhibitors of matrix metalloproteinases, inducible nitric oxide synthetase, intracellular signaling pathways such as P38, MEK-1/2, peroxisome-proliferator-activated receptors, and vitamin D. Molecular strategies to inhibit destructive inflammatory cytokines and matrix metalloproteinases and promote to chondrocyte survival and synthesis of cartilage matrix components such as type II collagen and proteoglycans are additional areas of scientific development.
Intra-articular therapies should be considered for patients with peripheral OA with symptoms despite maximal analgesics but may also be a viable therapeutic alternative for patients in whom NSAID or COX-2 inhibitor use is contraindicated or risky.
Intra-articular Glucocorticoid Agents
Intra-articular depot corticosteroids may be considered in management of accessible peripheral joints and are proven to achieve short-term relief from painful symptoms. When proper technique is employed, the risks of bleeding and septic arthritis are comparable to phlebotomy. Although recurrent administration is generally well tolerated and has not been observed to result in joint damage, more definitive surgical intervention should be considered.
Hyaluronic Acid Derivatives
The intra-articular delivery of synthetic and naturally occurring hyaluronan derivatives have gained popularity in management of mild-to-moderate OA of the knee and hip. Several injections are required for the different compounds, and some patients may experience a flare of symptoms after injection. In general, these agents are tolerated as well as corticosteroid injections. Thus far, long-term administration of these agents also appears to be safe.
Surgical intervention should be considered in patients with OA who have persistent, function-limiting symptoms despite maximal medical management and who are healthy enough to withstand surgery. Several surgical options exist, each with specific indications.
Arthroscopy with Debridement
Arthroscopy allows direct visualization to assess structural integrity of the joint and is most appropriate for patients with mechanical symptoms (locking and giveway weakness) because of meniscal defects that are either repaired or removed. Arthroscopic lavage for OA of the knee and other joints is controversial but has been used in combination with viscosupplementation as a temporizing measure pending more definitive surgery.
Osteotomy follows the principle of transferring load to the unaffected compartment of the knee. High tibial osteotomy is appropriate for OA, involving a single compartment in a varus malaligned knee. High tibial osteotomy achieves effective pain relief and restoration of mobility function in up to 90% of patients at 5 years, and 65% at 10 years. Postoperative alignment is the primary determinant of successful pain relief and may delay the need for joint replacement for up to 10 years. Therefore, young patients with varus malalignment who desire a fully active lifestyle that includes recreational sports are ideal candidates for osteotomy. When appropriately performed, osteotomy should not compromise later arthroplasty if it becomes necessary.
Arthroplasty, prosthetic joint replacement surgery, should be considered for patients who have function-limiting symptoms that have persisted despite receiving maximal medical and nonmedicinal treatment. Arthroplasty can replace either a single compartment (unicompartment) or the total joint.
It may be considered for patients who are nonobese with discrete pain and disease that is localized to the medial compartment of the knee and who have less than 10% varus malalignment, at least 90 degrees of motion without a flexion contracture, and who do not intend to return to high impact activities. Unicompartmental knee replacement can be achieved through a smaller surgical incision and shorter postoperative and rehabilitative course than total joint arthroplasty. Approximately 95% of unicompartment prostheses survive to 10 years.
Isolated disease of the patellofemoral joint of the knee occurs in up to 10% of patients with OA of the knee. Several types of patellofemoral arthroplasties are available, but the results have been variable, highlighting the need for careful selection of patients. The most common complications following surgery are patella maltracking, excessive wear of the polyethylene implant, and disease progression in the other compartments of the knee joint.
In contrast to patients with discrete symptoms, total joint arthroplasty is more appropriate for patients with diffuse OA of the knee or hip. Total knee replacement achieves rapid and long-term symptom relief in and functional recovery for 85% of patients with severe and diffuse disease of the knee or hip. With advances in design, prosthesis survival has improved to 90% at 15 years. However, arthroplasty revision is occasionally required for persistent and severe symptoms or prosthesis loosening. Flexion contracture and obesity are not contraindications for total joint arthroplasty but may complicate functional recovery.
Bilateral Knee Arthroplasty
For patients with severe bilateral knee OA, one might entertain bilateral simultaneous arthroplasty—that is replacement of both knees during a single operative session. Existing literature suggests that, in carefully selected patients, bilateral arthroplasty can be performed simultaneously and can achieve good outcomes without increasing perioperative risk.
Several different surgical procedures are available (trapeziectomy, trapeziectomy with ligament reconstruction, trapeziectomy with ligament reconstruction and tendon interposition, and joint replacement) and can lessen pain and improve function in patients with advanced OA of the thumb base. The specific type of procedure recommended will depend on durability and stability requirements of the patient's occupation and recreational activities.
Restorative Tissue Interventions
Transplantation of autologous chondrocytes has been used successfully to repair discrete defects in articular cartilage. Osteochondral transplantation is also promising. However, because the area of cartilage loss in OA in older adults is usually more extensive and because older chondrocytes are less metabolically active than young chondrocytes, transplantation to repair or replace diffusely degenerating cartilage is currently impractical.