Introduction: Shoulder joint is the most unstable and frequently dislocating joint because of its anatomy and biomechanics. In most patients shoulder instability occurs after a clear traumatic insult. According to one estimate, up to 96% of acute shoulder dislocations were traumatic in origin. It is sometimes difficult to identify a clear mechanism of injury that resulted in shoulder instability. This may be true in patients with underlying ligamentous laxity or in patients whose shoulder musculature has been deconditioned. For these patients, the onset of instability can be associated with minimal or no significant trauma. Some cases of instability are the result of a violent high-energy trauma, and may be associated with other soft-tissue or bony damage. The aim of this study was to look into the etiology of primary dislocation in our patient population so that a most suitable treatment option can be provided from a wide array of options possible.

Materials and Methods: This study was conducted in the Postgraduate Department of Orthopaedics, Bone & Joint Hospital, Associated to Government Medical College Srinagar, and a Tertiary Care Referral Hospital from October 2013 to April 2016. 225 unselected patients of either gender in the age group of 20 to 40 years, attending to OPD or emergency Department, with recurrent anterior shoulder instability were asked about the mode of trauma at the time of their primary dislocation.

Results: Among 225 patients 189 were males and 36 were females. Right side, dominant side in all the patients, was involved in 180 (80%) patients and left in 45 (20%) patients. Traumatic etiology was found in 198 (88%) patients and atraumatic etiology in 27 (12%) patients.Direct trauma to shoulder caused by fall on affected shoulder or RTA accounted for 44% of cases and indirect trauma like fall on outstretched limb or lifting of heavy weight or overhead throwing activity accounted for 44% of cases. Mild trauma accounted for 12% of cases. So major traumatic event was a cause in majority of cases.

Conclusion: Majority of our patients had sustained macro traumatic event as a cause of their primary dislocation with 198 patients (88%) having macro traumatic etiology and 27 patients (12%) patients having micro traumatic or atraumatic etiology. Most striking difference in our patients compared to western population in terms of etiology is that most of the patients in west are high collision contact athletes.

Keywords: Recurrent anterior shoulder instability, Primary dislocation, high contact collision sports .