AAOS Appropriate Use Criteria (2014)

The American Academy of Orthopaedic Surgeons (AAOS) has developed an Appropriate Use Criteria (AUC) to determine the appropriateness of non-arthroplasty treatment of osteoarthritis of the knee (OAK). The full document is available online at http://www.aaos.org/research/Appropriate_Use/oakauc.asp, along with a web-based app that can be used on a mobile device. An “appropriate” healthcare service is one for which the expected health benefits exceed the potential negative consequences by a sufficiently wide margin based on evidence and corroborated by consensus. There is no cure for OAK, and therapy is directed at controlling pain and maintaining functional activity. Evidence-based information from the literature, in conjunction with the clinical expertise of physicians from multiple medical specialties (orthopaedic surgery, rheumatology, and physical medicine and rehabilitation) and from a physical therapist, was used to develop a set of characteristics relevant to the non-arthroplasty treatment of OAK in order to create a matrix of scenarios. The RAND/UCLA Appropriateness Method (RAM)1 was used. Scenarios were created to mirror the spectrum of patients encountered using eight features: function-limiting pain, knee range of motion, ligamentous instability, pattern of arthritic involvement, radiographic imaging, limb alignment, mechanical symptoms, and age. Each of the 576 scenarios was then paired with evidence-based recommended treatments that were generated by the recent AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee: Evidence-Based Guideline, 2nd Edition;2 these include self-management programs, prescribed physical therapy, knee brace, NSAIDs, narcotic medications, tramadol, acetaminophen, intra-articular corticosteroids, arthroscopic partial meniscectomy or loose body removal, and realignment osteotomy. The treatments in this larger set of more than 4,000 combinations were then given scores of appropriateness by a separate panel of physicians (orthopaedic surgery, rheumatology, physical medicine and rehabilitation) and a physical therapist through a voting process. The outcome was the assignment of levels of appropriateness for each of the treatments, per patient scenario, between those that would be appropriate, those that would not, and those that might be, but with less strength/consensus. Incidence and Prevalence With increasing life expectancy, the burden of disease associated with osteoarthritis (OA) is rising sharply. In 2005, 27 million people in the United States were estimated to have symptomatic OA, with the knees, hands, and hips being the most common sites.3 Estimates of the prevalence of OA vary, affecting 20% to 30% of adults across different populations,4 and there may be significant discrepancies between radiographic findings and clinical symptomatology. OA involving the knee may affect the medial tibiofemoral, lateral tibiofemoral, and/or patellofemoral compartments. Osteoarthritic changes reduce the effectiveness of load transfer across the joint, and knee function may be impaired. OAK can greatly limit daily activities and is associated with a significant increase in healthcare expenditures.5 Compared with men, women are at greater risk for prevalent and incident OAK, and prevalent OAK is significantly more severe among women.6 Common symptoms of OAK include joint pain, stiffness with both knee activity and at rest, and ambulation difficulties, including instability. Physical findings include reduced joint range of motion, crepitus, bony enlargement related to osteophyte formation, pseudolaxity deformity, and effusion in approximately 30% of patients. Obesity is a strong risk factor for OAK,7,8 with a nearly three times higher risk for incident OAK among the obese and overweight compared with normal-weight individuals.8 Any increase in body weight increases the load across the joint by a force threefold to sevenfold greater than the actual weight gain. Knee alignment can contribute to this stress, with varus alignment especially vulnerable to excess body weight. Weight change can be significant; subjects who gained >5 lb had an almost fourfold greater risk for incident OAK compared with those who gained or lost <5 lb. In a study of women, decreasing body mass index (BMI) by approximately 5 kg over 10 years decreased the odds of OAK.9 Obesity also exacerbates pain and functional limitations from OAK.10 Conversely, weight loss in obese patients with OAK—particularly if accompanied by an increase in physical activity—improves physical function and quality of life.3,11,12 Light to moderate physical activity, including the 2008 Department of Health and Human Services physical activity guidelines of ≥150 minutes of moderate activity per week, does not increase the risk of OAK.7,13,14 However, heavy activity may be strongly associated with incident OAK.15 Occupations requiring repetitive overuse of the knee confer an increased risk of OAK.16 Crouching, kneeling, squatting, climbing stairs, and lifting heavy loads all cause abnormal loading across the joint and may result in tissue damage. Knee injury is a strong predictor of OAK.17,18 Most such injuries involve rupture of the anterior cruciate ligament, which is often associated with tearing of the meniscus or the medial collateral ligament. Knee alignment has a strong influence on load distribution across the joint. Varus alignment is associated with incident and progressive tibiofemoral OAK, and valgus alignment is associated with progressive tibiofemoral OAK.19 The degree of malalignment is correlated with the magnitude of joint space narrowing.20 Proprioception, which helps to establish and maintain joint stability, is decreased in both the involved and uninvolved knees of patients with unilateral OAK.17 Many patients with symptomatic OAK have quadriceps weakness.21 Originally, this was attributed to disuse atrophy secondary to knee pain, but such extensor weakness is also present with asymptomatic tibiofemoral OA—suggesting that quadriceps weakness is a risk factor for OAK. The following hypothetical cases highlights how the AAOS Clinical Practice Guideline and the accompanying AUC can help the clinician in deciding the course of treatment of patients with OAK. Patient 1 History of Present Illness A 68-year-old retired postal worker presents reporting medial right knee pain after he walks more than nine holes on the golf course. The patient reports no recent trauma and has no other joint involvement. He admits to being overweight and feels that his symptoms have increased after “putting on the last 10 pounds.” He states that his pain level is approximately 3 (of a maximum of 10) on a visual analog scale. He denies so-called mechanical symptoms such as locking, catching, and giving way. He has taken acetaminophen for his pain, with little effect. He is in good overall health, with essential hypertension well controlled with medication. He has no known allergies. Brief Physical Examination The patient is obese (BMI, 31.0 kg/m2), and his gait is normal. During ambulation, the right knee appears in slight varus alignment compared with the left knee. The knee range of motion is full, without significant instability. There is mild to moderate pain with palpation over the medial joint line; McMurray’s circumduction test is negative. There is no obvious effusion. Gross strength testing appears to be normal, but there is mild vastus medialis obliquus atrophy on the right compared with the left thigh. Imaging Studies Standing AP, PA flexion, and Merchant radiographs of both knees, as well as a lateral view of the right knee, were obtained. Asymmetric medial joint space narrowing (Kellgren-Lawrence grade 1-2) was noted in the medial compartment of the symptomatic right knee on the PA flexion view (Figure 1). There are no osteophytes and there is no significant deformity.Figure 1: Patient 1. PA flexion radiograph demonstrating asymmetric medial joint space narrowing (Kellgren-Lawrence grade 1-2) in the medial compartment of the symptomatic right knee.Diagnosis and Management The diagnosis of OAK was discussed with the patient. His orthopaedic surgeon used the AUC app at AAOS (https://aaos.webauthor.com/go/auc/) to counsel him regarding treatment options. This tool refers to the recommendations put forth in the AAOS Clinical Practice Guideline Treatment of Osteoarthritis of the Knee: Evidence-Based Guideline, 2nd Edition and is based on a systematic review of the literature, in conjunction with clinical experience from multiple specialties.2 It covers 10 relevant treatments approved by the AUC writing panel.22 The patient was encouraged to initiate a program of strengthening of the hamstring and quadriceps muscles, as well as to participate in low-impact aerobic exercise. The physician facilitated enrollment in a 6-week self-management class given through his local hospital that provides instruction on exercises; teaches neuromuscular education, activity modification, and weight control; and offers education for strategies of self-management of OA. After the orthopaedist recommended that the patient discuss the use of NSAIDs with his primary care provider, the patient took a short course (6 weeks) of over-the-counter naproxen sodium 440 mg, twice a day, with meals, during the initiation of his aerobic exercise program. His primary care provider monitored his blood pressure, which was not adversely affected by this medication. The AUC and AUC app list the use of NSAIDs and acetaminophen and prescribed physical therapy as Appropriate self-management programs. Weight loss is an inherent assumed recommendation of the AUC and should be encouraged; in this patient, weight gain seemed to be a major factor that precipitated symptoms. The physician chose to start with a self-management program and a course of NSAIDs because the patient was motivated and had already tried acetaminophen without effect. Prescribed physical therapy was not necessary initially but ultimately was used. The patient’s symptoms significantly improved after initiation of treatment. Through exercise and diet, he was able to lose weight. He was able to discontinue his NSAIDs after 6 weeks, with no recurrence of pain with golfing. When vastus medialis obliquus atrophy was noted at follow-up and the patient asked for a referral, a 4-to-6–session course of structured physical therapy was offered. Prescribed physical therapy, supported as Appropriate by the AUC, was now most beneficial. The patient had regular follow-up and, after 3 years, symptoms recurred. NSAIDs at that time were less effective, and the patient underwent therapeutic corticosteroid injection to complement his comprehensive nonsurgical management program. The AUC and AUC app list as May Be Appropriate intra-articular corticosteroids and tramadol. Tramadol was not necessary in this case. The AUC and AUC app list as Rarely Appropriate a hinged knee brace and/or unloading brace, narcotic medicine for refractory pain, arthroscopy, and realignment osteotomy. Patient 2 History of Present Illness A 48-year-old woman presents with intermittent pain in both knees that has continued during the past 10 years. She does not recall a specific precipitating factor, including trauma. The pain has been progressively increasing over time and has become “unbearable” during the past several weeks. Her weight has gradually increased over the past 5 years to 170 lb. She does not participate in any regular exercise and is fairly sedentary at work and at home. She indicates that her average pain is 7 out of a maximum of 10. She has moderate impairment with her activities of daily living, including shopping and doing housework, because of knee pain. She experiences pain when walking short distances and when getting in and out of her car. Her pain is relieved by sitting, lying, or resting. She notes occasional “clicking” of her knee as well as giving way when she is walking on uneven surfaces. Her pertinent history includes hypertension, which is controlled with medication, as well as peptic ulcer disease. She uses alcohol, usually two drinks per night. Brief Physical Examination The patient is overweight (BMI, 27.2 kg/m2). Knee examination reveals a moderate varus deformity with mild bilateral effusions. Both knees demonstrate full range of motion without evidence of ligamentous instability. The medial joint line is moderately tender to palpation in both knees. Crepitus is noted in the left knee but not the right. She has 4/5 strength on manual muscle testing with knee extension and flexion, which is likely due to pain; the remainder of her neurologic examination is benign. Her gait is slow and mildly antalgic, with a shortened step length. Imaging Studies Standing AP radiographs and sunrise views of both knees show mild to moderate OA in the medial compartment (Kellgren-Lawrence grade 3 in left knee and grade 2 in right) (Figure 2). Findings were questionable for the patellofemoral compartment (grade 1 bilaterally), and there was no evidence of OA in the lateral compartments of either knee. Moderate varus deformity was apparent in both knees, left greater than right.Figure 2: Patient 2. AP radiographs of the right (A) and left (B) knees and lateral radiographs of the right (C) and left (D) knees demonstrating mild to moderate osteoarthritis in the medial compartment (Kellgren-Lawrence grade 2 in the right and grade 3 in the left knee).Treatment This case is representative of a significant number of patients with OAK seeking care for the first time. The patient is a middle-aged, sedentary, mildly overweight woman with acute, asymmetric worsening of knee pain limiting activity and causing mechanical symptoms, with an examination showing stable, varus, mild to moderate medial compartment disease, and radiographs confirming the same. In this scenario, the AUC tool would list as Appropriate treatment recommendations the following: self-management programs, prescribed physical therapy, use of NSAIDs and acetaminophen, and arthroscopy. May Be Appropriate treatments include bracing, intra-articular corticosteroid injections, tramadol, and realignment osteotomy; use of narcotics is listed under Rarely Appropriate. Tailoring the options to the patient’s situation and other conditions is important. Because of her peptic ulcer disease and alcohol use, NSAIDs would have to be used with caution, perhaps with a proton pump inhibitor for prophylaxis or use of a cyclooxygenase-2 NSAID. Acetaminophen or tramadol could be considered for pain management. Because her recent weight gain and increasingly sedentary lifestyle are concurrent with worsening of the pain, the patient is a good candidate for a conservative approach using a self-management program and prescribed physical therapy. Corticosteroid injections in both knees, although a May Be Appropriate intervention, may assist with the pain and help her initiate changes in her daily activities as well as with a walking program. Weight loss is an inherent assumed recommendation of the AUC and should be encouraged. Self-management programs, such as the Arthritis Foundation Exercise Program, provide information on exercise, weight control, stress management, and healthy eating. Outpatient physical therapy for 6 to 8 weeks should focus on improving her lower extremity strength and function and the synergistic development of her home exercise and walking programs. OAK is frequently asymmetric. Even if the one knee improves, mechanical symptoms and/or pain might persist on the other side. If mechanical symptoms predominate, an MRI would have value; if an unstable meniscus tear or loose body is demonstrated, arthroscopy would be considered appropriate. This is one of the few scenarios in the AUC in which an osteotomy, in this case of the proximal tibia, would be considered as a May Be Appropriate option if nonsurgical management fails. The patient does not have obesity and does have a moderate varus deformity, stable ligaments, and unicompartmental disease. An osteotomy might be coupled with arthroscopy, depending on MRI findings and the degree of certainty of its being isolated disease. A trial of bracing could also be one of the May Be Appropriate treatments to consider before surgery. Patient 3 History of Present Illness A 90-year-old woman reports right knee pain, buckling, catching, and giving way of the knee when she tries to ambulate, as well as frequent pain at rest and at night. Her activity level is severely curtailed, and she has had to move into an assisted-care facility. She has become increasingly depressed because of her arthritis and is “losing interest in life.” She has significant visual impairment and a history of congestive heart failure. Brief Physical Examination The patient has a moderately severe valgus deformity. She has anterior cruciate ligament laxity to anterior drawer and Lachman tests and pseudolaxity of the lateral collateral ligament. She has a flexion contracture of 10° and flexes to only 105°. There is crepitus, predominantly at the lateral joint line, and moderate knee swelling. She has significant loss of muscle mass in her upper leg. Imaging Studies Radiographs demonstrated severe tricompartmental OA, primarily in the lateral compartment, where there is complete loss of joint space (Figure 3).Figure 3: Patient 3. PA flexion radiograph of the right and left knees demonstrating tricompartmental severe osteoarthritis, primarily in the lateral compartment, where there is complete loss of joint space.Treatment This patient’s situation is at the far end of the spectrum of the AUC scenarios. She is an elderly patient with a history of rest pain and mechanical symptoms; joint contractures, deformity, and laxity; major limitation of activities; and severe radiographic OA. Using the AUC, the following grades of recommendations are displayed as Appropriate: self-management, physical therapy, acetaminophen, NSAIDs, tramadol, and corticosteroid injections. Treatment options displayed as May Be Appropriate include bracing, arthroscopy, and narcotics. Rarely Appropriate options are limited to osteotomy. This scenario is a reminder that the AUC is a guide to be used in the context of the patient’s age and health as a whole. This patient’s advanced age and comorbidities add an obligation to reconsider the implications of some of the Appropriate versus May Be Appropriate interventions. NSAIDs have a progressive of and in the elderly and might be more in the of limited and a history of congestive heart failure. Physical therapy might be because of and If not intermittent intra-articular corticosteroid injections a risk and may provide some pain The risk of using a hinged knee brace is in this with of The brace may help of and the risk of which in this case could have There may be concurrent OA and the brace should be to put with a and This is a case in which limited narcotics for pain might be depending on other medical conditions as well as to and other Tramadol and acetaminophen would be initially over narcotics. Even arthroscopy is listed as a May Be Appropriate is given the increased risk and of especially given the advanced findings on physical examination and The AUC for the to if mechanical symptoms are related to a meniscus tear or loose In this if the more that the mechanical symptoms are most likely a result of the advanced OA, the AUC for arthroscopy would have been lower and not an the patient has an obvious deformity, her instability, and of range of motion all that an osteotomy is in this Self-management involving education and walking exercise, as well as prescribed physical therapy, would have the potential for some without recommendations would be for the patient and should be considered before other options. OAK is in a of across a of patients with a wide range of The of this AUC used the most common pertinent patient characteristics and coupled with the evidence-based management recommendations corroborated by consensus. 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