Frequency of Corticosteroid Injections for Frozen Shoulder
For adhesive capsulitis (frozen shoulder), corticosteroid injections are typically administered as a single injection or a series of up to 3 injections given weekly, with the decision to re-inject based on individual response to the initial injection(s).
Evidence-Based Injection Protocols
Single vs. Multiple Injection Approach
A single intra-articular corticosteroid injection is often sufficient and provides significant pain relief and functional improvement for 2 to 24 weeks in patients with adhesive capsulitis 1
A series of 3 weekly intra-articular injections was used successfully in comparative studies, showing superior results to oral corticosteroids in objective shoulder scores, range of motion, and patient satisfaction 2
The optimal approach appears to be starting with a single injection and reassessing response before considering additional injections 3, 4
Timing of Response and Re-injection Decisions
Evaluate treatment response at 2 weeks post-injection - if no symptomatic improvement occurs by this timeframe, the injection has likely failed and alternative treatments should be considered 5
Peak therapeutic effect typically occurs at 1-2 weeks, with duration of benefit lasting 1-3 months in most cases 5
The decision to re-inject should be individualized based on benefits from previous injections, with consideration that if frequent re-injections are needed, alternative or additional therapies should be pursued 6
Dosing Considerations
Low-dose (20 mg) triamcinolone acetonide is as effective as high-dose (40 mg) for adhesive capsulitis, indicating the preferred use of a low dose in the initial stage 3
Both 20 mg and 40 mg doses showed significant improvement in pain and function compared to placebo, with no significant difference between the two dose groups 3
Stage-Specific Treatment Approach
Early Stage (Stage 1) Disease
Patients with stage 1 adhesive capsulitis (significant improvement in pain and normalization of motion following injection) recovered at a mean of 6 weeks (range: 2 weeks to 3 months) 7
Early recognition and prompt injection may be both diagnostic and therapeutic 7
Freezing Stage (Stage 2) Disease
Patients with stage 2 disease (significant improvement in pain and partial improvement in motion) recovered at a mean of 7 months (range: 2 weeks to 2 years) 7
A single injection applied before beginning physical therapy provides faster pain relief and earlier improvement compared to oral NSAIDs, with significant differences observed up to 8 weeks 4
Important Clinical Caveats
Contraindications and Precautions
Do not administer intra-articular steroids unless an appropriate diagnosis has been made and contraindications have been ruled out 6
Diabetic patients must be informed about transient hyperglycemia risk and advised to monitor glucose levels, particularly days 1-3 post-injection 6
Patients using protease inhibitors (antiretroviral therapy) should not receive triamcinolone due to drug-drug interaction risk of iatrogenic Cushing syndrome 1
Corticosteroids may be less beneficial for diabetic patients with adhesive capsulitis 1
Post-Injection Management
Avoid joint overuse for 24 hours following injection, but immobilization is discouraged 6
Always use aseptic technique 6
Approximately 13% of patients experience injection-site soreness or muscle aches, making it the most common delayed adverse event 8
Some patients may experience a temporary increase in pain (post-injection flare) during the first 24-48 hours before experiencing improvement 8
Practical Algorithm
Initial injection: Single intra-articular corticosteroid injection (20 mg triamcinolone acetonide preferred) 3
Assess at 2 weeks: Evaluate for symptomatic improvement 5
- If improved: Continue physical therapy, monitor response
- If no improvement: Consider alternative diagnosis or treatment
Re-injection consideration: If initial benefit wanes before full recovery (typically within 1-3 months), consider repeat injection 5, 1
Maximum series: Up to 3 weekly injections may be used, though single injection is often sufficient 2, 3
If frequent re-injections needed: Add or adjust to alternative therapies rather than continuing repeated injections 6
The evidence does not support a rigid schedule of repeated injections, but rather a response-based approach where the need for additional injections is determined by the clinical response to initial treatment.