Recurrent instability after a first-time anterior traumatic shoulder dislocation can exceed 26%. This paper systematically reviewed risk factors which predispose this population to events of recurrence. Ten studies comprising 1324 participants met the criteria for inclusion. Recurrent instability after a first-time traumatic anterior shoulder dislocation was 39%. Greater risk of recurrent instability was reported in people aged 40 years and under (OR=13.46), in men (OR=3.18) and in people with hyperlaxity (OR=2.68). Reduced risk of recurrent instability was reported in people with a greater tuberosity fracture (OR=0.13). The rate of recurrent instability decreased as time from the initial dislocation increased. Other factors such as a bony Bankart lesion, nerve palsy and occupation influenced rates of recurrent instability.
Sex, age at initial dislocation, time from initial dislocation, hyperlaxity and greater tuberosity fractures were key risk factors in at least two good quality cohort studies yielding strong evidence as concluded in the GRADE criteria. Although bony Bankart lesions, Hill Sachs lesions, occupation, physiotherapy treatment and nerve palsy were risk factors for recurrent instability, the evidence was not strong using the GRADE criteria-these findings were dependent on poorer quality studies or were inconsistent among studies.