Diagnosing the direction of shoulder instability in rugby players

The muscular characteristics of rugby players may make diagnosing the direction of shoulder instability and labral pathology challenging. This study aimed to assess the accuracy of clinical examination and specifically instability tests, in diagnosing the direction of shoulder instability in rugby players. One-hundred-and-forty rugby players, who had undergone a shoulder stabilization procedure, over a 55-month period, were included in this study. The mean age was 21.5 years with 137 males. Data collected included clinical examination and intraoperative findings. The two were compared to calculate the diagnostic accuracy of special tests for instability. The Anterior Apprehension Test had good sensitivity (82.7%), specificity (100%) and PPV (100%) but poor NPV (55.8%). All posterior instability tests demonstrated a sensitivity of over 85%, but all had a specificity of 25% or less. In 83.6% of cases the direction of instability was correctly identified from history and examination. Anterior instability was correctly diagnosed in 78.9% of cases and posterior in 100.0%. The poor NPV of the anterior apprehension test suggests that clinicians should be suspicious of anterior instability in rugby shoulders even in the light of negative examination findings. Positive posterior instability tests are highly suggestive of posterior instability in rugby players.