Note from the National Guideline Clearinghouse (NGC): The following key points summarize the content of the guideline. Refer to the full text of the original guideline document for additional information, including detailed information on dosing, possible side effects, and cost of medications; risk factors; and subspecialty referrals.
The levels of evidence (A, B, C, D) are repeated at the end of the Major Recommendations field.
Diagnosis
The majority of knee pain is caused by patellofemoral syndrome and osteoarthritis [evidence: D].
Magnetic resonance imaging (MRI) of the knee has been proven not to be superior to the clinical exam by an experienced examiner in the evaluation of acute knee injuries [A].
Magnetic resonance imaging may be useful to assess bone pathology underlying chronic knee pain [D].
Differentiating between knee pain without constitutional symptoms, knee pain with constitutional symptoms, and traumatic knee pain is helpful in determining a diagnosis (refer to Figures 1, 2, and 3 in the original guideline document for details).
Patients with knee pain and swelling who have non-bloody aspirates may also have serious knee pathology (refer to Figure 4 in original guideline document for details).
Treatment
Exercises are important. Many knee conditions will improve with conservative treatment consisting of low-impact activities and exercises to improve muscular strength and flexibility. Patellofemoral dysfunction is best treated with vastus medialis strengthening and hamstring and calf stretching [B].
In most cases a home treatment program should be explained in detail to the patient, including specific guidelines for activity modification and exercises. Initially, formal physical therapy is usually not required.
All patients with mild to moderate knee osteoarthritis who do not have medical contraindications should be offered an exercise program that includes lower extremity strengthening and stretching exercises combined with low impact aerobic exercises (e.g., swimming, biking, walking, cross-country skiing) [A].
The initial drugs of choice for the treatment of the pain of knee osteoarthritis are acetaminophen and/or topical capsaicin [A]. If a traditional non-steroidal anti-inflammatory drug (NSAID) is indicated, the choice should be based on cost (refer to Table 6 in original guideline document for details). Cyclooxygenase-2 (COX-2) inhibitors are no more effective than traditional NSAID agents; they may offer a short-term but probably no long-term advantage in gastrointestinal (GI) tolerance for some patients. Due to cost and increased heart attack risk, COX-2 inhibitors should be reserved for carefully selected patients (refer to Table 7 in the original guideline document for details).
Follow-up
Symptoms should not be allowed to persist for more than 12 weeks before a reevaluation of the condition, along with possible consultation with physical therapy or a musculoskeletal specialist (e.g., orthopedic surgeon, rheumatologist, physiatrist, or sports medicine specialist) [D].
Definitions:
Levels of Evidence
Levels of evidence for the most significant recommendations
- Randomized controlled trials
- Controlled trials, no randomization
- Observational trials
- Opinion of expert panel
