Summary
Injections may be used both as a diagnostic aid and to provide therapeutic relief for common acromioclavicular, glenohumeral, rotator cuff, biceps, and suprascapular shoulder pathologies.
7 Diagnostic and Therapeutic Injections
I. General overview
Injections can be diagnostic to determine source of pain/injury or therapeutic to provide temporary relief:
Diagnostic for:
Acromioclavicular (AC) joint pathology
Rotator cuff tears
Subacromial impingement
Anterolateral pain syndrome
Glenohumeral joint pathology
Suprascapular nerve entrapment
Biceps tendon pathology.
Therapeutic injections:
Provides pain relief for multiple conditions, including but not limited to: osteoarthritis, rheumatoid arthritis, adhesive capsulitis, calcific tendinitis, rotator cuff tears, subacromial bursitis, biceps tendinitis, and impingement
To be used after other conservative therapies (nonsteroidal anti-inflammatory drugs [NSAIDs], physical therapy, disease-modifying agents for rheumatoid arthritis) have failed
Typically a combination of corticosteroid and anesthetic
Immediate relief suggests drug is delivered accurately to site of pain
Relief in hours or days is reflective of systemic absorption of corticosteroid
May see relief for up to 6 months
May receive not more than three to four injections per year:
i. Avoid repeat injections for biceps tendon pathology to avoid risk of rupture.
Can aid in adjunctive physical therapy (e.g., calcific tendinitis):
i. See ▶ Table 7.1 for commonly used preparations.
Technique:
Accuracy may be improved with ultrasound guidance
Performed with sterile technique and consistent pressure
Aspiration before injection avoids intravascular injection
Agent should flow freely when injected into articular space
Anesthetic injection in overlying soft tissue with a 25 gauge needle is optional
Passive manipulation after injection aids in dispersion of the therapeutic
Patient should be monitored in office for up to half an hour following injection
Avoid strenuous activity for at least 48 hours following injection.
Contraindications:
Absolute:
Suspected infection
Prosthetic joint
Intratendinous injections.
Relative:
Prior adverse reaction
Active skin lesions at site of injection
Anticoagulant use or elevated international normalized ratio (INR).
Complications and side effects
Skin atrophy or depigmentation of injection site
Postinjection flare from crystal deposition, generally resolves in 48 hours
Infection occurs rarely (1:2,000 to 1:20,000 injections), typically begins after 48 hours
Single intra-articular injections have negligible effects on glycemic control
Soft tissue injection or peri-tendinous injections may elevate blood glucose (from 5 to 21 days) and may require closer glycemic monitoring.
There are no studies showing lasting benefit from platelet enriched plasma injections for shoulder pathology
Diagnosis of shoulder pathology is made from a combination of physical examination, imaging, and injection.