What is the best course of treatment for a patient with shoulder pain that worsens with arm abduction and improves with a Medrol (methylprednisolone) dose pack?

Management of Shoulder Pain That Worsens with Arm Abduction

For a patient with shoulder pain that worsens with arm abduction and improves with methylprednisolone, subacromial corticosteroid injection is the recommended treatment, as this presentation strongly suggests subacromial impingement syndrome.

Diagnosis

Pain that increases with arm abduction is a classic sign of shoulder impingement syndrome, where the rotator cuff tendons and subacromial bursa become compressed between the humeral head and the acromion during arm elevation. This diagnostic finding is important because:

• Pain with abduction is characteristic of subacromial pathology 1
• The positive response to methylprednisolone (Medrol) dose pack indicates an inflammatory component
• This presentation is consistent with subacromial bursitis, rotator cuff tendinopathy, or partial tear 2

Treatment Algorithm

First-Line Treatment

1. Subacromial corticosteroid injection

   • Methylprednisolone acetate 40mg with lidocaine 1% (total volume 1ml) 3, 2
   • Provides more rapid pain relief compared to triamcinolone 4
   • Evidence level B for effectiveness in subacromial region inflammation 1

2. Analgesics

   • NSAIDs (ibuprofen, naproxen) or acetaminophen if no contraindications 1, 2
   • Evidence level C for pain relief 1

3. Physical therapy

   • Gentle stretching and mobilization techniques focusing on external rotation and abduction 1, 2
   • Avoid overhead pulley exercises which can worsen symptoms 1
   • Strengthen weak muscles in the shoulder girdle 1
   • Evidence level B for effectiveness 1

Second-Line Treatment (if inadequate response after 4-6 weeks)

1. Repeat corticosteroid injection if initial response was positive but temporary 2
2. Advanced imaging (MRI) to assess for rotator cuff tear 1, 2
3. Intensified physical therapy with focus on scapular stabilization 2

Third-Line Treatment (if inadequate response after 3-6 months)

1. Surgical referral for consideration of arthroscopic subacromial decompression 2

Imaging Considerations

• Initial imaging: Plain radiography with anteroposterior views in internal and external rotation, and axillary or scapula-Y view 1, 2
• Advanced imaging: MRI shoulder without contrast (rated 7/9 for appropriateness) or MR arthrography (rated 9/9) if labral pathology is suspected 1
• Ultrasound can be equally effective for evaluating the rotator cuff and is rated 9/9 for suspected bursitis 1

Treatment Efficacy

• Approximately 80% of patients recover completely within 3-6 months with appropriate conservative treatment 2
• Methylprednisolone provides relief of pain of 50% or more in 92% of patients compared to 50% with triamcinolone 4
• Two months post-injection, 50% of patients receiving methylprednisolone report total relief of pain 4

Important Caveats

• Avoid shoulder immobilization with arm slings or wraps as it can lead to frozen shoulder 2
• Delaying physical therapy intervention should be avoided, as early treatment is crucial 2
• If full shoulder function is not achieved by 6-8 weeks, intensive physical therapy should be instituted to avoid permanent dysfunction 2
• Some studies show no long-term benefit of corticosteroid injection for post-traumatic impingement 5, highlighting the importance of combining injection with appropriate rehabilitation

The combination of corticosteroid injection and targeted physical therapy provides the best outcomes for patients with shoulder pain that worsens with abduction, addressing both the inflammatory component and the underlying biomechanical issues.