What is the treatment for recurrent knee swelling?

Treatment for Recurrent Knee Swelling

The treatment approach depends critically on identifying the underlying cause—infectious arthritis (including Lyme disease), crystal-induced arthropathy (CPPD), or osteoarthritis—with initial management focusing on NSAIDs and/or colchicine for inflammatory conditions, while reserving intra-articular corticosteroids only after infection is excluded and antibiotics have failed in Lyme arthritis.

Lyme Arthritis with Recurrent Swelling

For patients with persistent or recurrent joint swelling after initial antibiotic treatment, re-treatment with another 4-week course of oral antibiotics (doxycycline, amoxicillin, or cefuroxime axetil) is recommended first, particularly if arthritis has improved but not completely resolved 1.

• If arthritis failed to improve at all or worsened after oral therapy, intravenous ceftriaxone for 2-4 weeks should be administered 1.
• Wait several months before initiating re-treatment to allow for the anticipated slow resolution of inflammation after antibiotic therapy 1.
• During this waiting period, NSAIDs may be used for symptom control 1.
• Intra-articular corticosteroid injections are NOT recommended during active infection or while awaiting response to antibiotics 1.
• If arthritis persists despite intravenous therapy AND synovial fluid PCR is negative, symptomatic treatment with NSAIDs, intra-articular corticosteroids, or DMARDs (hydroxychloroquine) is appropriate 1.
• Arthroscopic synovectomy may reduce the duration of joint inflammation if persistent synovitis causes significant pain or functional limitation 1.

Critical Pitfall

Be vigilant for subtle neurologic symptoms (distal paresthesias, memory impairment) even in patients presenting primarily with arthritis, as these require intravenous β-lactam antibiotics rather than oral therapy 1.

Calcium Pyrophosphate Deposition (CPPD) with Chronic Inflammatory Arthritis

For chronic CPP crystal inflammatory arthritis causing recurrent knee swelling, low-dose colchicine (0.5 mg twice daily) or NSAIDs combined with gastro-protective agents are first-line treatments 1.

• Colchicine demonstrated an NNT of 2 for clinical response (>30% pain reduction) at 4 months in patients with knee OA and persistent CPPD inflammation 1.
• NSAIDs should be combined with proton pump inhibitors, especially in older patients or those requiring long-term use 1.
• Hydroxychloroquine is an effective option for chronic inflammatory arthritis with CPPD, with an NNT of 2 for clinical response (>30% reduction in swollen/tender joint count) 1.
• For severe CPPD refractory to conventional treatment, low-dose methotrexate (5-10 mg/week) showed excellent clinical response in uncontrolled trials, with significant decreases in pain intensity, joint counts, and attack frequency 1.
• Low-dose glucocorticoids may be considered based on expert opinion, though no trial data supports this 1.

Important Considerations

Intra-articular high molecular weight hyaluronan should be avoided in CPPD as it may induce acute attacks 1. Intra-articular corticosteroids are appropriate only after infection is excluded and for symptomatic relief in treatment-refractory cases 1.

Osteoarthritis with Recurrent Effusion

For recurrent knee swelling due to osteoarthritis, treatment follows standard OA management principles focusing on pain reduction, maintaining function, and limiting progression 1.

• Non-pharmacological interventions (patient education, exercise, weight management) form the foundation of treatment 1.
• Pharmacological options include paracetamol, NSAIDs, and topical treatments 1.
• When CPPD coexists with OA, the inflammatory component may be more prominent and require the treatments outlined above 1.

Diagnostic Evaluation Required

When knee popping accompanies recurrent swelling with pain, locking, or giving way, obtain AP, lateral, sunrise/Merchant, and tunnel view radiographs as initial imaging 2.

• Physical examination must assess for joint effusion, tenderness, loss of motion, and crepitus 2.
• If radiographs reveal structural abnormalities or if symptoms persist despite normal radiographs, MRI is the appropriate next step to detect meniscal tears, articular cartilage damage, and bone marrow lesions 2.
• Arthrocentesis with synovial fluid analysis (cell count, crystals, culture, PCR) is essential to differentiate infectious, crystal-induced, and inflammatory causes 1, 3.

Critical Diagnostic Pitfall

Reactive arthritis and septic arthritis can present similarly and even coexist; inflammatory parameters may increase after intra-articular corticosteroid injection in septic arthritis, making infection exclusion mandatory before steroid administration 3.