What is the recommended evaluation and management of shoulder pain in a patient with diabetes?

Shoulder Pain in Diabetics: Evaluation and Management

Initial Diagnostic Approach

Begin with plain radiographs (AP, Grashey, axillary, and scapular Y views) as the mainstay of initial imaging to rule out fracture, dislocation, and significant osteoarthritis. 1

Clinical Evaluation Priorities

• Assess for adhesive capsulitis (frozen shoulder), which affects 14-62% of diabetic patients and is characterized by gradual onset shoulder pain with severe restriction of both active and passive range of motion, particularly external rotation 2, 3, 4
• Document duration of diabetes, glycemic control (HbA1c), and presence of other diabetic complications (retinopathy, neuropathy), as these correlate with shoulder manifestations 3, 5
• Examine for bilateral involvement and associated hand symptoms or hip restriction, as the triad of shoulder pain, hand symptoms, and restricted hip mobility indicates clinically advanced diabetes with higher rates of proliferative retinopathy 3
• Rule out calcific periarthritis, which causes pain and limited mobility but typically has better prognosis than frozen shoulder 2
• Consider reflex sympathetic dystrophy (shoulder-hand syndrome) if vasomotor and sudomotor changes are present in the affected limb 2

Key Clinical Caveat

Diabetic patients with shoulder pain after shorter diabetes duration in type 2 versus type 1 diabetes, but both groups show similar frequency of shoulder joint affection. 3 The high frequency of insulin treatment and classical late complications indicates these patients have clinically advanced diabetes mellitus 3.

Advanced Imaging When Radiographs Are Noncontributory

• MRI without contrast is the procedure of choice for evaluating occult fractures and soft tissues (tendons, ligaments, muscles, labrocapsular structures) 1
• Ultrasound with appropriate local expertise is excellent for depicting rotator cuff and biceps pathology, and is the preferred modality to guide injections and aspirations 1
• MRI or MRA are modalities of choice in patients aged <35 years with shoulder pain and in those with instability or questionable labral pathology 1

Management Algorithm

Step 1: Optimize Glycemic Control

Target HbA1c of 6-7% immediately, as poor glycemic control contributes to fibrotic processes causing shoulder stiffness and is associated with multiple diabetic complications including shoulder manifestations. 6, 2, 7, 5

• Address cardiovascular risk factors (hypertension, hyperlipidemia) aggressively, as these contribute to diabetic complications 6
• Recognize that shoulder stiffness in diabetics is due to fibrotic processes similar to other diabetic complications (arterial stiffness, pancreatic/renal fibrosis) 7

Step 2: Conservative Management for Adhesive Capsulitis

Initiate physiotherapy with gentle stretching and mobilization techniques, focusing on increasing external rotation and abduction gradually while restoring alignment and strengthening weak shoulder girdle muscles. 1, 2

• Prescribe acetaminophen or NSAIDs for pain relief if no contraindications exist 1, 2
• Active range of motion should be increased gradually in conjunction with restoring alignment 1

Step 3: Interventional Options

For pain related to spasticity or muscle tightness, inject botulinum toxin into subscapularis and pectoralis muscles. 1

For pain thought to be related to subacromial pathology (rotator cuff or bursa inflammation), administer subacromial corticosteroid injections. 1, 2

• Use ultrasound or fluoroscopic guidance for injections and aspirations 1
• Consider hyaluronan injections for osteoarthritis if present 2

Step 4: Surgical Referral

Refer patients with continued disabling pain unresponsive to conservative measures (physiotherapy, NSAIDs, corticosteroid injections) for at least 3-6 months to orthopedic surgery. 2

Special Considerations for Surgical Outcomes

Evidence regarding diabetes as a prognostic factor for rotator cuff surgery outcomes is inconclusive. Two level III studies showed conflicting results: one found no significant difference in postoperative stiffness between diabetic and nondiabetic patients at 46 months, while another found statistically significant differences in ASES scores favoring patients without diabetes, though no difference in infection rates 1

Monitoring and Prevention

• Screen diabetic patients regularly for shoulder symptoms, as the clinical course can last for months with remaining long-term disabilities 7
• Recognize that multiple factors including age, diabetes duration, HbA1c, advanced glycation end products (AGE), VEGF, and IL-1β are associated with tendon changes and increased capsular stiffness leading to limited ROM 5
• The cause of shoulder complications remains incompletely understood despite confirmed high prevalence in diabetic patients 5