Are Rotator Cuff Tears in Anterior Shoulder Dislocation Associated With a High Critical Shoulder Angle? A...

Area of Science:

• Orthopedic Surgery
• Radiology
• Sports Medicine

Background:

• Acute rotator cuff tears (RCT) are common following traumatic anterior glenohumeral dislocation.
• The critical shoulder angle (CSA) is a radiographic measurement proposed as a potential predictor of shoulder pathologies.
• Reliability of CSA measurements in patients with first-time anterior shoulder dislocation requires evaluation.

Purpose of the Study:

• To determine if the critical shoulder angle (CSA) can effectively screen for acute rotator cuff tears (RCT) in patients with first-time anterior glenohumeral dislocation.
• To assess the inter- and intra-observer reliability of CSA measurements in this patient cohort.

Main Methods:

• Retrospective review of patients with first-time anterior shoulder dislocation over a 17-month period.
• Three shoulder surgeons independently measured CSA on post-reduction radiographs.
• Patients underwent imaging to detect traumatic rotator cuff tears (RCT); statistical analysis included unpaired t-tests and Cronbach's alpha for reliability.

Main Results:

• Sixty-five patients met inclusion criteria; 65% had detectable rotator cuff tears.
• No significant difference in mean CSA was found between the tear (38.14°) and non-tear (37.45°) groups (p = 0.5598).
• Increasing age was significantly associated with a higher likelihood of RCT (p = 0.0225); inter-observer reliability was 'good' (0.8519), intra-observer reliability was 'excellent' (≥0.9282).

Conclusions:

• The critical shoulder angle (CSA) is not a significant predictor of rotator cuff tears following traumatic anterior shoulder dislocation.
• Increasing patient age is a significant risk factor for rotator cuff tears in this context.
• CSA measurements demonstrate good to excellent inter- and intra-observer reliability, suggesting potential for other applications but not as a screening tool for RCT post-dislocation.