What is the best course of treatment for a 57-year-old man with shoulder pain, worsened by overhead lifting and relieved by rest, with tenderness over the greater tuberosity and relief from lidocaine injection into the subacromial space?

Treatment for Subacromial Impingement Syndrome

Begin with a structured 3-6 month trial of conservative management consisting of physical therapy targeting rotator cuff and scapular stabilizer strengthening combined with NSAIDs before considering any invasive interventions. 1

Initial Conservative Management (First-Line Treatment)

This patient presents with classic subacromial impingement syndrome—positive Hawkins and Neer tests, pain with overhead activities, night pain, tenderness over the greater tuberosity, and diagnostic relief with subacromial lidocaine injection. 1, 2

Conservative treatment is the established standard initial approach: 1

• Structured physical therapy program targeting:

  • Rotator cuff strengthening (supraspinatus, infraspinatus, subscapularis, teres minor) 1
  • Scapular stabilizer strengthening—critical since scapular dyskinesis significantly contributes to impingement pathology 1
  • Periscapular muscle strengthening to address the mechanical dysfunction causing the painful arc 1

• NSAIDs should be prescribed concurrently with the exercise program 1

• Duration: Commit to 3-6 months of this regimen before considering any invasive options 1

Role of Corticosteroid Injections

The evidence for subacromial corticosteroid injections is weak and inconsistent: 3

• One level II study found no statistically significant difference between corticosteroid with lidocaine versus lidocaine alone at 6 weeks 3
• Five level II studies show variable results between 2-6 weeks, highlighting the temporary and inconsistent nature of this intervention 1
• Cannot recommend for or against subacromial injections based on current evidence 3

Clinical caveat: While the diagnostic lidocaine injection confirmed the pain source, therapeutic corticosteroid injections should not be relied upon as primary treatment given the inconclusive evidence and concerns about potential adverse effects on tendon biology. 3

When Surgery Is NOT Indicated

Surgery should NOT be considered until after 3-6 months of failed conservative treatment. 1

• Current evidence does not support subacromial decompression surgery as first-line treatment 1
• It does not provide clinically important improvements in pain, function, or quality of life compared to conservative treatments 1
• The primary indication for rotator cuff surgery is significant pain that has failed conservative management, not the mere presence of pathology 3

Practical Implementation Algorithm

1. Weeks 0-4: Initiate NSAIDs and refer to physical therapy with specific prescription for rotator cuff and scapular stabilizer strengthening 1

2. Weeks 4-12: Continue structured therapy program; assess compliance and progress 1

3. Months 3-6: If inadequate improvement, consider advanced imaging (MRI) to evaluate for rotator cuff tear and reassess treatment plan 1

4. After 6 months: Only if conservative management has definitively failed should surgical consultation be considered 1

Common Pitfalls to Avoid

• Do not rush to corticosteroid injection as primary treatment—the evidence does not support this approach and it may delay appropriate physical therapy 3, 1

• Do not refer for surgical evaluation prematurely—the vast majority of patients improve with conservative management 1, 4

• Ensure physical therapy is truly structured and supervised—generic "home exercises" are insufficient; the program must specifically target rotator cuff and scapular stabilizers 1

• Do not discontinue NSAIDs prematurely—they should be continued throughout the conservative treatment period unless contraindicated 1