The mechanism underlying anterior, or better antero-inferior, shoulder dislocation is a traumatic injury with or without contact during abduction and external rotation. The diagnosis of anterior dislocation is established on the basis of a physical examination which shows a change in the anatomical profile of the shoulder, more evident in less muscular, leaner athletes, with loss of subdeltoid contour and often the humeral head in the antero-inferior portion of the axilla. The patient reports anterolateral shoulder pain, described as internal, which normally subsides when the dislocation is reduced. During this phase the physician needs to carefully assess the possible presence of associated nerve lesions. Confirmation is provided by a radiographic series (true AP and true lateral and axillary views) to assess both the presence of the dislocation and possible associated humeral or glenoid bony lesions. A thorough history is also crucial, during which the patient should be asked whether he/she had previous episodes of partial dislocation or sensation of instability or whether he/she remembers the manner in which the trauma causing the dislocation occurred.

The dislocation should be reduced as soon as possible and possibly at the first attempt so as to avoid adding further tissue injuries due to failed attempts at reduction. For this reason and because athletes often have a particularly well-developed musculature, it is best to perform the reduction following anaesthesia or deep sedation and possibly under imaging guidance. Once the dislocation has been reduced, the resulting shoulder stability should be tested with gentle movements and clearly without forcing with specific tests against resistance; the patient should be assessed contralaterally and from a general point of view in order to identify any congenital laxity that might complicate the decision-making process. A post-reduction radiogram is obtained, followed by other imaging investigations that will help decide on the most appropriate treatment strategies. These will include an unenhanced magnetic resonance (MR) examination to assess the soft tissues, supplemented by contrast-enhanced scans in the event of doubts in the interpretation of capsular ligamentous structures, and a computed tomography (CT) study with 3D reconstructions to assess bony defects of the glenoid and humeral head in terms of both size and position. At this point the physician has all the information necessary to decide on which treatment to perform – whether conservative or surgical and, if surgical, the best procedure. We should always remember the characteristics of the natural history of shoulder dislocations, which include a high rate of recurrences, progressive damage to the stabilising structures and the fact that early arthroscopic treatment is beneficial to young athletes under the age of 25 whether involved in noncontact or contact-collision sports [7, 8, 10, 11, 16]. We can in fact identify and treat all lesions, understand the quality of the tissue and its healing capacity, using a noninvasive method associated with a low complication rate.

Our treatment algorithm for a first-time anterior shoulder dislocation in an athlete is to perform an arthroscopic stabilisation procedure as soon as possible, within a week at the most. When necessary, we prefer to use small-diameter bioabsorbable anchors and high-resistance threads in order to avoid problems related to metal and its possible mobilisation. Recently we have started to use soft anchors with great satisfaction, as these have the advantages described above with the added benefit of an excellent pull-out strength and major sparing of bone tissue. Arthroscopy enables the complete study of both the articular space and the subacromial and subcoracoid spaces [17] and thus allows us to treat any associated lesions in the same session. Early repair allows us to exploit the natural biological tendency to heal without interfering with the surgical procedure. Problems may arise due to bony lesions and especially simultaneous humeral and glenoid lesions and anterior HAGL lesions. In the case of bony Bankart lesions [18], treatment is arthroscopic, with a possibility for open stabilisation in the event of extensive glenoid fractures. Depending on position, Hill-Sachs lesions are sometimes treated with an arthroscopic remplissage procedure [19]. When the two bony lesions are combined, with evident loss of the glenoid track, the choice is between an open or arthroscopic Latarjet procedure in the case of contact-collision sports; however, we are always doubtful in athletes younger than 20 years of age engaged in noncontact, non-collision sports or overhead sports since the Latarjet procedure completely disrupts shoulder anatomy, and it is a replacement rather than a repair procedure [20, 21]. Some authors [22] have suggested adopting a preoperative score to assess the severity of the instability and help choose the most appropriate procedure. However, in our opinion, this score is too unbalanced, and young athletes easily attain scores indicating a need for the more aggressive Latarjet stabilisation procedure. Moreover, we agree with other authors [16] that this score is only a part of a puzzle that requires validation by prospective studies. HAGL lesions are treated arthroscopically or with open surgery depending on whether they are associated with major subscapularis lesions. Following the surgical procedure, the patient is placed in an ultrasling shoulder brace in neutral position for 4 weeks; several times a day, gentle wrist, elbow and shoulder mobilisation movements of the pendulum type are prescribed – but not external rotations and abductions.

The conservative approach is reserved for lower-level athletes over the age of 30 engaged in noncontact-collision sports and no overhead sports and who do not have bony lesions, HAGL lesions or rotator cuff lesions. Even in this case postoperative care consists of immobilisation with an ultrasling shoulder brace in neutral position for 4 weeks.

As stated above, we clearly take into account the level of the athlete and the timing of the dislocation in relation to the competitive season. A temporary conservative treatment allowing the athlete to complete the season consists of the ultrasling shoulder brace for 2/3 weeks followed by functional recovery on land and in water to restore range of motion; only after this has been restored can the athlete start exercises to strengthen the muscles and restore specific athletic movement. Very important are early exercises for the scapulothoracic joint aiming at mobilisation and progressive strengthening of its stabilisers. Return to play in these cases is estimated at around 6/8 weeks, but may take longer in the case of overhead athletes.

In the event of arthroscopic surgical stabilisation, functional recovery after removal of the shoulder brace takes place in a similar fashion, with recovery of first passive and then active motion – always within the pain threshold – strengthening exercises after 2/3 months, sports-specific exercises after 3/4 months and finally return to play after 5/6 months. In the event of a Latarjet stabilisation procedure, after 4 weeks of ultrasling shoulder brace in neutral position and follow-up radiography, functional recovery takes place using the same methods but with a shorter timeframe, and the athlete can return to play ca. 3/4 months after radiography or 3D computed tomography has confirmed that the graft has consolided. Unfortunately, however, in many cases due to the needs of the athlete or his or her family and pressure from the coaches and media, return to play is permitted before complete healing of the tissues, and this exposes the athlete to recurrences and the surgeon and rehabilitators to having to justify a treatment failure.