Depo-Medrol Dosing for Knee Injection
For knee osteoarthritis, use 40-80 mg of methylprednisolone acetate (Depo-Medrol) per injection, with 40 mg being the standard effective dose and higher doses (60-80 mg) reserved for severe acute flares with large effusions. 1, 2
Standard Dosing Protocol
- The FDA-approved dose range for large joints like the knee is 20-80 mg 2
- 40 mg provides clinically meaningful benefit and is the most commonly studied dose 3, 4, 5
- 60-80 mg may be considered for severe acute exacerbations with significant effusion, though evidence for superior efficacy at higher doses is limited 1, 5
Clinical Indications
Intraarticular glucocorticoid injections are strongly recommended by the American College of Rheumatology for knee osteoarthritis, particularly during acute pain flares 6, 1
- Injections are especially indicated when effusion is present, though benefit occurs even without effusion 6
- The presence of localized inflammation (warmth, swelling, effusion) supports the decision to inject 3
- Pain severity is the strongest predictor of response—patients with more severe pain tend to benefit most 5
Frequency and Safety Limits
Limit injections to no more than 3-4 per year in the same knee to minimize potential cartilage toxicity 1
- Repeat injections at intervals of 1-5 weeks or longer depending on symptom relief, with most patients requiring repeat injection every 3 months 2, 4
- Long-term studies using triamcinolone 40 mg every 3 months for 2 years showed no radiographic joint space narrowing compared to placebo, supporting safety of repeated injections 4
- The ACR acknowledges concerns about cartilage loss with certain steroid preparations or frequent injections, but the clinical significance remains uncertain 6, 1
Administration Technique
Mix the methylprednisolone with 4-5 mL of 1% lidocaine for injection 2, 7, 3
- Use sterile technique with a 20-24 gauge needle inserted directly into the synovial space 2
- Aspirate a few drops of synovial fluid to confirm intra-articular placement before injecting 2
- After injection, move the joint gently a few times to distribute the medication throughout the synovial cavity 2
Critical Timing Considerations
Avoid injection within 3 months of planned knee replacement surgery due to increased infection risk 1, 8
- Monitor diabetic patients closely for hyperglycemia on days 1-3 post-injection 1, 8
- Symptom relief typically begins within 24 hours but may take up to 1-2 weeks for full effect 6, 7
- Duration of benefit averages 4-12 weeks, with considerable individual variation 6, 4
Evidence Limitations
Insufficient data exists to definitively recommend low versus high doses within the therapeutic range 6, 1
- One study comparing 40 mg versus 80 mg methylprednisolone for epidural injection found comparable efficacy, suggesting lower doses may be adequate 9
- No additional benefit was demonstrated from ultrasound guidance for knee injections, unlike hip injections where imaging is strongly recommended 6
- Adding corticosteroid injection before exercise therapy provides no additional benefit over exercise alone, so injection should be reserved for symptomatic flares rather than routine pre-treatment 3