I. General overview

1. 
   

   Injections can be diagnostic to determine source of pain/injury or therapeutic to provide temporary relief:

   
   
   
   
   1. 
      

      Diagnostic for:

      
      
      
      
      1. 
         

         Acromioclavicular (AC) joint pathology

         
         
      2. 
         

         Rotator cuff tears

         
         
      3. 
         

         Subacromial impingement

         
         
      4. 
         

         Anterolateral pain syndrome

         
         
      5. 
         

         Glenohumeral joint pathology

         
         
      6. 
         

         Suprascapular nerve entrapment

         
         
      7. 
         

         Biceps tendon pathology.

      
      
   2. 
      

      Therapeutic injections:

      
      
      
      
      1. 
         

         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

         
         
      2. 
         

         To be used after other conservative therapies (nonsteroidal anti-inflammatory drugs [NSAIDs], physical therapy, disease-modifying agents for rheumatoid arthritis) have failed

         
         
      3. 
         

         Typically a combination of corticosteroid and anesthetic

         
         
      4. 
         

         Immediate relief suggests drug is delivered accurately to site of pain

         
         
      5. 
         

         Relief in hours or days is reflective of systemic absorption of corticosteroid

         
         
      6. 
         

         May see relief for up to 6 months

         
         
      7. 
         

         May receive not more than three to four injections per year:

         
         
         
         
         • 
           

           i. Avoid repeat injections for biceps tendon pathology to avoid risk of rupture.

         
         
      8. 
         

         Can aid in adjunctive physical therapy (e.g., calcific tendinitis):

         
         
         
         
         • 
           

           i. See ▶ Table 7.1 for commonly used preparations.

           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           
           

           Table 7.1 Commonly used preparations for therapeutic shoulder injections

           Site	Syringe (in mL)	Anesthetic* (in mL)	Corticosteroid** (in mL)
           Acromioclavicular joint	3 to 5	0.5	0.25 to 0.5
           Subacromial space	10	5 to 7	1 to 2
           Glenohumeral joint	10	5 to 7	1 to 2
           Biceps tendon area	3 to 5	0.5	0.25
           Scapulothoracic articulation	3 to 5	1 to 2	0.5 to 1.0
           Notes: *1% lidocaine or 0.25 to 0.5% bupivacaine. **Betamethasone sodium phosphate and acetate (Celestone Soluspan) or methylprednisolone (Depo-Medrol, 40 mg/mL) or triamcinolone acetonide (Kenalog, 40 mg/mL). Recommend a 21 to 25 cc gauge needle, 1.5 inches, depending on site of injection.

   
   
2. 
   

   Technique:

   
   
   
   
   1. 
      

      Accuracy may be improved with ultrasound guidance

      
      
   2. 
      

      Performed with sterile technique and consistent pressure

      
      
   3. 
      

      Aspiration before injection avoids intravascular injection

      
      
   4. 
      

      Agent should flow freely when injected into articular space

      
      
   5. 
      

      Anesthetic injection in overlying soft tissue with a 25 gauge needle is optional

      
      
   6. 
      

      Passive manipulation after injection aids in dispersion of the therapeutic

      
      
   7. 
      

      Patient should be monitored in office for up to half an hour following injection

      
      
   8. 
      

      Avoid strenuous activity for at least 48 hours following injection.

   
   
3. 
   

   Contraindications:

   
   
   
   
   1. 
      

      Absolute:

      
      
      
      
      1. 
         

         Suspected infection

         
         
      2. 
         

         Prosthetic joint

         
         
      3. 
         

         Intratendinous injections.

      
      
   2. 
      

      Relative:

      
      
      
      
      1. 
         

         Prior adverse reaction

         
         
      2. 
         

         Active skin lesions at site of injection

         
         
      3. 
         

         Anticoagulant use or elevated international normalized ratio (INR).

   
   
4. 
   

   Complications and side effects

   
   
   
   
   1. 
      

      Skin atrophy or depigmentation of injection site

      
      
   2. 
      

      Postinjection flare from crystal deposition, generally resolves in 48 hours

      
      
   3. 
      

      Infection occurs rarely (1:2,000 to 1:20,000 injections), typically begins after 48 hours

      
      
   4. 
      

      Single intra-articular injections have negligible effects on glycemic control

      
      
   5. 
      

      Soft tissue injection or peri-tendinous injections may elevate blood glucose (from 5 to 21 days) and may require closer glycemic monitoring.

   
   
5. 
   

   There are no studies showing lasting benefit from platelet enriched plasma injections for shoulder pathology

   
   
6. 
   

   Diagnosis of shoulder pathology is made from a combination of physical examination, imaging, and injection.