What are the management options for a patient presenting with knee pain?

Management of Knee Pain

Start with acetaminophen up to 4,000 mg/day combined with exercise therapy and patient education as first-line treatment for most patients with knee pain. 1, 2, 3

Initial Clinical Assessment

Your evaluation should focus on these specific red flags that determine urgency:

• Weight-bearing status: Have the patient take at least 4 steps—inability to bear weight requires urgent evaluation 3
• Range of motion: Document if the knee can flex to 90 degrees 3
• Joint effusion: Palpate for swelling, which may indicate inflammatory processes or structural damage 3
• Trauma history: Severe pain, swelling, and instability following acute trauma requires urgent referral 4
• Infection signs: Fever, erythema, swelling, and limited range of motion suggest septic arthritis requiring immediate attention 4

Age-specific considerations matter: Teenage girls and young women typically have patellar tracking problems, while teenage boys have extensor mechanism issues; adults over 45 with activity-related pain and less than 30 minutes of morning stiffness likely have osteoarthritis (95% sensitivity, 69% specificity) 5, 6

Imaging Strategy

Obtain plain radiographs (AP, lateral, Merchant/sunrise, and tunnel views) only if: 3, 4

• Pain has persisted more than 6 weeks, OR
• Acute trauma meets evidence-based criteria for imaging, OR
• Physical examination reveals effusion, suspected fracture, or signs of degenerative changes

Reserve MRI for specific situations: 1, 3

• Surgery is being considered
• Pain persists despite 6+ weeks of adequate conservative treatment
• Initial radiographs are normal but symptoms continue
• Evaluating meniscal pathology, cartilage lesions, or bone marrow edema

The 2021 VA/DoD guidelines explicitly recommend against obtaining MRI for initial diagnosis of hip and knee osteoarthritis 1

First-Line Treatment Algorithm

Step 1: Pharmacotherapy + Non-Pharmacological Interventions

Acetaminophen: 1, 2, 3

• Dose: Up to 4,000 mg/day in adults
• This is the preferred long-term oral analgesic due to favorable safety profile (adverse events only 1.5%)
• Evidence shows similar efficacy to ibuprofen 2,400 mg/day and naproxen 750 mg/day for knee pain

Topical NSAIDs for knee pain specifically: 1, 2

• Strong recommendation for knee osteoarthritis
• Particularly appropriate for patients ≥75 years old due to better safety profile than oral NSAIDs
• Note: Insufficient evidence for hip pain due to joint depth

Exercise therapy (mandatory, not optional): 1, 3

• Regular, progressive strengthening focused on quadriceps
• Load progression individualized based on tissue tolerance
• For patellofemoral pain: hip and knee strengthening exercises combined with foot orthoses or patellar taping 6

Patient education: 1, 3

• Explain that pain does not correlate with tissue damage
• Discuss recovery time frames and build confidence
• Promote autonomy and self-management

Weight reduction if overweight: 1, 2

• Large cohort studies show weight loss reduces risk of knee osteoarthritis
• Refer to obesity management guidelines for comprehensive lifestyle intervention

Step 2: If Inadequate Response After 2-4 Weeks

Add or switch to oral NSAIDs: 1, 2, 7

• Ibuprofen 1,200-3,200 mg daily (400-800 mg three to four times daily)
• For patients with increased GI risk: use non-selective NSAIDs with gastroprotective agents OR selective COX-2 inhibitors
• The smallest effective dose should be employed; most patients respond adequately to 2,400 mg/day

Consider topical capsaicin for knee pain: 1

• Requires continuous use for 2-4 weeks before therapeutic effect
• Moderate effect size (standard mean difference 0.44) for knee osteoarthritis
• May cause local burning or stinging initially

Add supportive interventions: 1, 2

• Prefabricated foot orthoses (when patient responds favorably to treatment direction tests) 1
• Bracing for knee osteoarthritis 1
• Walking sticks or insoles to reduce pressure 1

Step 3: For Acute Flares with Effusion

Intra-articular corticosteroid injection: 1, 2, 3

• Indicated specifically for pain flares accompanied by effusion
• Provides short-term pain relief
• Use for persistent pain inadequately relieved by other interventions

Step 4: Consider Physical Therapy Referral

Refer to physical therapy if: 1

• Pain or functional limitation has not improved with initial treatment
• Patient needs structured, supervised exercise program
• Alternative delivery models (group visits, Internet-based, telephone-based) are equally effective

Important Caveats

Avoid opioids (including tramadol): The 2021 VA/DoD guidelines provide a weak recommendation against initiating opioids for knee pain 1

Duloxetine as alternative: Consider for patients with inadequate response or contraindications to acetaminophen or NSAIDs specifically for knee osteoarthritis 1

Manual therapy: May improve pain and function when added to exercise, particularly when symptoms are severe 3

Surgical Referral Indications

Refer for surgical consultation when: 1, 3

• Radiographic evidence of osteoarthritis with refractory pain and disability despite conservative treatment
• Specific mechanical pathology identified (e.g., bucket-handle meniscal tear with displaced tissue)
• Persistent symptoms despite 6+ weeks of adequate conservative treatment with concerning MRI findings
• End-stage osteoarthritis (minimal joint space with inability to cope with pain) after exhausting all appropriate conservative options

Note: For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even with mechanical symptoms like locking or catching 6

Reassessment Timeline

Reassess at 6 weeks if no favorable outcomes observed; consider MRI if not yet obtained and symptoms persist 3