Are steroids useful in treating knee pain likely related to soft tissue injury?

Steroids for Knee Pain from Soft Tissue Injury

Intra-articular corticosteroid injections provide short-term pain relief (1-4 weeks) for knee pain related to soft tissue injury, particularly when accompanied by effusion, but their benefit is limited and should be reserved for acute exacerbations rather than routine use. 1, 2

Evidence for Efficacy

• Corticosteroid injections demonstrate clinically significant pain reduction with effect sizes up to 1.27 compared to placebo at one week, translating to approximately 1.0 cm improvement on a 10-cm visual analogue scale 1, 3

• Benefits are moderate at 1-2 weeks post-injection, small to moderate at 4-6 weeks, minimal at 13 weeks, and absent by 26 weeks 3

• The number needed to treat for beneficial outcome is 8 for pain relief and 10 for functional improvement 3

• For soft tissue injuries specifically, corticosteroids are effective for acute nonspecific tenosynovitis, epicondylitis, and acute exacerbations with effusion 4, 5

When to Use Steroids

Steroids are most appropriate for:

• Acute flares of knee pain with effusion - this is the strongest indication, as presence of effusion predicts better response 4, 2, 6

• Acute soft tissue injuries including tenosynovitis and epicondylitis 5, 7

• Patients who have failed initial management with acetaminophen and NSAIDs 2

• When rapid symptom relief is needed (within 1-2 weeks) 1, 3

However, one randomized crossover study found no clinical predictors of response, suggesting injections should not be limited only to patients with effusion 4, though the weight of evidence still favors their use in this setting.

Administration Technique

• Use strict aseptic technique to minimize infection risk (occurs in 1 in 14,000-50,000 injections) 7

• For knee injections, imaging guidance is not required 1

• Dosing for knee joints: 5-15 mg for larger joints, up to 40 mg for larger areas 5

• If excessive synovial fluid is present, aspirate some (but not all) before injection to aid pain relief and prevent steroid dilution 5

• For tenosynovitis, inject into the tendon sheath rather than the tendon substance itself 5

• For epicondylitis, infiltrate into the area of greatest tenderness 5

Critical Safety Concerns

Recent evidence raises significant concerns about potential harm:

• Corticosteroid injections are associated with a 57% increased risk of requiring knee arthroplasty (hazard ratio 1.57,95% CI 1.37-1.81), with each injection increasing absolute risk by 9.4% at nine years 8

• Concerns exist that frequent injections may contribute to cartilage loss, though clinical significance remains debated 1, 8

• Avoid injections within 3 months prior to planned knee replacement surgery due to increased infection risk 1

• Patients should avoid overuse of the injected joint for 24 hours following injection 1

• Monitor glucose levels for 1-3 days post-injection in diabetic patients due to transient hyperglycemia risk 1

Treatment Algorithm for Soft Tissue Knee Injury

1. First-line: Non-pharmacological approaches (rest, ice, compression, elevation) plus acetaminophen up to 4g/day 2

2. Second-line: NSAIDs (oral or topical) for patients unresponsive to acetaminophen 2

3. Third-line: Intra-articular corticosteroid injection for acute exacerbations, particularly with effusion or significant inflammation 1, 2

4. Avoid: Repeated frequent injections given concerns about cartilage damage and increased arthroplasty risk 1, 8

Common Pitfalls

• Expecting long-term benefits - evidence only supports 1-4 weeks of meaningful relief, not months 4, 3, 9

• Overuse of repeated injections - given the increased arthroplasty risk, a conservative approach is warranted 8

• Injecting into infected joints - always exclude septic arthritis before injection 5

• Injecting into unstable joints - generally not recommended as may cause further joint damage 5

• Failing to counsel patients about activity modification - patients should avoid overuse for 24 hours post-injection 1

Bottom Line

While corticosteroid injections provide short-term symptomatic relief for soft tissue knee injuries, particularly with effusion, their benefits are fleeting (1-4 weeks maximum) and emerging evidence suggests potential long-term harm including increased arthroplasty risk 3, 8. Use them judiciously for acute exacerbations only, not as routine or repeated therapy 1, 8.