To encounter the challenges of shoulder instability in a population younger than 20 years old, it is important to distinguish between the skeletally mature and immature population. It has been shown that because of the growing skeletally immature patient with open physes, traumatic shoulder events resulting in a shoulder dislocation are relatively rare. One of the first studies by Rowe investigating 500 shoulder dislocations found that 20% of these dislocations occurred to patients at the age between 10 and 20 but only about 2% to patients younger than 10 years [15]. Therefore, these pediatric traumas more often result in humeral physeal or metaphyseal fractures. In addition the younger patient population is showing a higher recurrence rate after first-time traumatic shoulder dislocation with a rate up to 100% in patients younger than 10 [15] and 60–94% between 10 and 20 years of age [5, 7, 15]. Children between 14 and 18 years of age are 24 times more likely to experience recurrent instability compared to infants aged 13 years and less, with a 14 times more likelihood of recurrent instability with a closed physis compared with those with an open physis [12]. There are several factors reported which may explain the high recurrence rate in this collective: (1) structural age-related factors such as a higher composition of collagen type III fibers in the glenohumeral capsule [18], (2) anatomical-related factors like a more lateral insertion of the capsules on the glenoid [14], or (3) the severity of impact during first-time traumatic shoulder dislocation with and without bony deficiency [9]. For these patients, treatment options are still debatable. Whether a conservative or an operative treatment is the best option has not finally been shown, due to the lack of differentiation between skeletally mature and immature patients. Most of the studies refer to an adolescent population, and some propose a surgical procedure due to the mentioned high recurrence rate. But each of these cases has to be considered individually, and factors like activity level, sports, and general conditions have to be taken into account before proposing a treatment option.

Another aspect that has to be considered in these young patients is the occurrence of hyperlaxity with joint hypermobility. The incidence in the skeletal immature population is estimated to be between 4% and 13% and not associated with soft tissue disease like the Ehlers-Danlos or Marfan syndrome [2, 19]. Among these individuals, the condition of shoulder hyperlaxity is somewhat higher in women with poor muscular development and adolescent overhead athletes, due to the activity demanding with increased flexibility and range of motion [8, 13]. These patients are able to maintain their stability by a balancing act of dynamic muscular compensation. However, these patients can suffer from a traumatic shoulder event interrupting this balancing act with a consequently structural damage, resulting in unidirectional shoulder instability [17]. Most of the time though, this young population with an increased laxity experiences several subluxations resulting in an elongation of the static shoulder stabilizing structures [16]. This pathological change between static bony and capsulo-labral anatomy and dynamic muscular stabilizers leads to a symptomatic multidirectional instability (MDI), an atraumatic instability in two or more directions [1, 17]. The recent literature reveals a variation of definitions of MDI, which makes the classification difficult, leading to a high variation of MDI diagnoses [10]. Even though there is limited data particularly regarding children and adolescents, the incidence of MDI is estimated to be approximately 10% because of increased capsular laxity associated with youth and seems to be even higher in overhead athletes [6]. Most of the recent literature proposed a conservative treatment in these atraumatic hyperlax shoulder instabilities, expecting a decline of symptoms through aging and maturation. The treatment consists of a specific program for muscular control [3]. If conservative treatment fails, these patients may benefit from surgical stabilization. The arthroscopic techniques nowadays provide similar results to the traditional used open capsular shift procedures [4, 11].