What are the primary outcome measures for shoulder dislocation?

Primary Outcome Measures for Shoulder Dislocation

The primary outcome measures for shoulder dislocation should include recurrence of instability (redislocation or subluxation), validated patient-reported shoulder instability measures, and return to pre-injury activities or sports. 1, 2

Key Outcome Measures

Instability Assessment

• Recurrence of instability is the most critical outcome measure, defined as another anterior shoulder dislocation requiring closed reduction, subluxation, or a positive apprehension test 3, 2
• Instability events should be prospectively recorded and categorized as either redislocations (requiring external assistance for reduction) or subluxations (partial dislocations) 4
• The American College of Radiology recommends proper imaging assessment with standard radiographs including anteroposterior views in internal and external rotation, plus axillary or scapula-Y views to properly assess glenohumeral alignment 1, 5

Patient-Reported Outcome Measures

• Validated patient-reported outcome measures specific for shoulder instability should be used, including:
  • Western Ontario Shoulder Instability Index (WOSI) 3, 4
  • Rowe score for evaluation of shoulder instability 4, 2
  • Walch-Duplay score for functional assessment 3
  • Disabilities of the Arm, Shoulder and Hand score (DASH) - short version 3

Functional Outcomes

• Range of motion measurements comparing the injured and uninjured shoulders 6
• Return to pre-injury activities or sports participation levels 3, 2
• Subjective shoulder value assessment 4
• Constant-Murley score for overall shoulder function 4

Imaging Assessment

• MR arthrography is the gold standard for evaluating recurrent shoulder instability, with superior assessment of labroligamentous injuries, Hill-Sachs lesions, and glenoid bone loss 1
• CT arthrography can be considered if MRI is contraindicated 1
• Assessment of specific pathologic findings such as glenoid bone loss, which is found in up to 10% of patients with recurrent instability 1

Secondary Outcome Measures

• Adverse events related to treatment (e.g., shoulder stiffness, infection, neurological complications) 2
• Patient satisfaction with treatment outcomes 2
• Health-related quality of life 2
• Long-term complications such as osteoarthritis 7

Measurement Timing

• Short-term follow-up at 3,6, and 12 weeks post-treatment 4, 6
• Medium-term follow-up at 6 and 12 months 4, 2
• Long-term follow-up at 24 months or longer to properly assess recurrence rates 3, 4, 2

Pitfalls to Avoid

• Failure to obtain proper radiographic views (axillary or scapula-Y views) may lead to missed diagnosis of dislocation 5
• Ultrasound should not be used as a primary diagnostic tool for shoulder instability assessment 1
• Relying solely on clinical examination without validated outcome measures may miss subtle instability 2
• Inadequate follow-up duration may underestimate recurrence rates, as many dislocations recur beyond the first year 2, 7