What is it?

1. What is it?

2. What Sport?

4. What happened?

5. Shoulder Instability • maintained by the glenohumeral ligaments, the joint capsule, the rotator cuff muscles, the negative intra-articular pressure, and the bony/cartilaginous anatomy. • The main stabilizers of the shoulder joint are the ligaments and the capsule complex. • Multiple ligaments are present, but the inferior glenohumeral ligament is the most important and the one most commonly injured during an anterior shoulder dislocation. • The injury may be a tear of the ligament/capsule off one of its bony attachments, and/or it may cause a stretch injury to these structures. • Tears in the rotator cuff muscles may also lead to shoulder instability. Four rotator cuff muscles are present in the shoulder. They are found superficial to the glenohumeral ligaments and the bones. Large tears may lead to shoulder instability, even with intact glenohumeral ligaments. • Instability of the shoulder can also occur from injury to the nerves that control the shoulder muscles, specifically the axillary nerve.

6. Shoulder instability A partial dislocation (subluxation) means the head of the upper arm bone (humerus) is partially out of the socket (glenoid). A complete dislocation means it is all the way out of the socket.

7. Shoulder • The shoulder is a very mobile joint; therefore, it is often placed in awkward positions during sports. • Thus, the force from a fall or a blow may be sufficient to cause shoulder damage. • If the force is strong enough, the athlete tears the ligaments/tendons, fractures the glenoid or humerus, and dislocates the shoulder.

9. Epidemiology • The shoulder is the most commonly dislocated joint in the body. • Although most shoulder dislocations occur anteriorly, they may also occur posteriorly, inferiorly, or anterior-superiorly. • Patients with a previous shoulder dislocation are more prone to redislocation. • Other factors that show a clear correlation to redislocation are the age of the patient and concomitant rotator cuff tears and fractures of the glenoid. • Younger patients (teenagers and those aged 20 years) have a much higher frequency of redislocation than patients in their 50s and 60s.[4] Many physicians believe that age is less of a predisposing risk factor for redislocation than activity level. • Patients who tear their rotator cuffs or fracture the glenoid during their shoulder dislocation have a higher incidence of redislocation than patients without these problems.

10. History • most dislocations happen from trauma, patients report feeling the shoulder pop out during the incident. • Different shoulder positions during the dislocation tear different ligaments. Thus, trying to determine the shoulder position at the time of the injury is important. • The most common dislocation is anterior. In an anterior dislocation, the patients report having their arm abducted and externally rotated. • Ask the patient if they had to go to the emergency department to have the shoulder reduced. If they did, they should have a radiograph of the dislocated shoulder. If they did not go to the emergency department, did the patient pop the shoulder back in or did it just go back in by itself? • Patients with very loose joints (hyperlaxity) report feeling like their joint rolls out of the socket. These patients can usually "roll" the shoulder back in. • previous shoulder dislocations are more apt to redislocate • Some patients feel stingers or numbness run down their arm at the time of the dislocation.

11. Causes • Approximately 95% of shoulder dislocations result from a major traumatic event, and 5% result from atraumatic causes. • With a traumatic dislocation, the cause is obvious; • atraumaticdislocations can result for different reasons. • Ligamentous lax shoulders may dislocate with little or no trauma. • Congenital causes, such as excessive retroversion of the humeral head or malformation of the glenoid, can lead to instability. • Neuromuscular causes, such as injury to the axillary nerve or cerebral palsy, have also been associated with s

12. Anterior (forward) • Over 95% of shoulder dislocation cases are anterior. Most anterior dislocations are sub-coracoid. • Sub-glenoid; subclavicular; and, very rarely, intrathoracic or retroperitoneal dislocations may occur. • It can result in damage to the axillary artery.

15. Posterior dislocations • are occasionally due to electric shock or seizure and may be caused by strength imbalance of the rotator cuff muscles. • Posterior dislocations often go unnoticed, especially in an elderly patient and in the unconscious trauma patient. • An average interval of 1 year was discovered between injury and diagnosis of posterior dislocation in a series of 40 patients. • Inferior (downward)

16. Inferior (downward) • Inferior dislocation is the least likely form, occurring in less than 1% of all shoulder dislocation cases. • This condition is also called luxatioerecta because the arm appears to be permanently held upward or behind the head. • It is caused by a hyper abduction of the arm that forces the humeral head against the acromion. • Inferior dislocations have a high complication rate as many vascular, neurological, tendon, and ligament injuries are likely to occur from this kind of dislocation.

17. Physical • If the patient has a dislocated shoulder, range of motion (ROM) is poor and the patient is in a lot of pain. If the shoulder is anteriorly dislocated, the arm is in slight abduction and external rotation. In patients who are thin, the prominent humeral head can be felt anteriorly and the void can be seen posteriorly in the shoulder. • Posterior shoulder dislocations can be easy to miss, because the patient usually keeps his or her arm in internal rotation and adduction (ie, the patient holds the arm up against his or her abdomen). • Posterior shoulder dislocations can be missed, because the patient appears to only be guarding the extremity. • If the proper radiographs are not obtained, the diagnosis will be missed (see Imaging Studies). • neurovascular examination before and after the shoulder has been reduced. Injury to the axillary nerve during shoulder dislocation has been reported to be as high as 40%.

18. Signs • Significant pain, which can sometimes be felt past the shoulder, along the arm. • Inability to move the arm from its current position, particularly in positions with the arm reaching away from the body and with the top of the arm twisted toward the back. • Numbness of the arm. • Visibly displaced shoulder. Some dislocations result in the shoulder appearing unusually square. • No bone in the side of the shoulder showing shoulder has become dislocated.

19. Differentials • AcromioclavicularJoint Injury • Bicipital Tendonitis • Clavicular Injuries • Rotator Cuff Injury • Shoulder Dislocation • Swimmer's Shoulder

20. Radiographs • When dealing with shoulder instability, obtaining 2 orthogonal views of the shoulder is imperative. • anteroposterior(AP) view of the shoulder and an axillary lateral view. • If an axillary lateral radiography cannot be obtained, then a scapular Y view may be taken in its place. • If good radiographs cannot be obtained, order a computed tomography (CT) scan. This study can be performed quickly and is not expensive. • Posterior shoulder dislocations can look like a normal shoulder on the AP view. If an orthogonal view radiograph is not obtained, the diagnosis may be missed. • The findings of one study show that younger patients (< 30 y) with mechanisms that are low risk for fractures are probably safe to reduce without prereduction radiography.[8]

21. Magnetic resonance imaging (MRI) • Glenohumeralligament tears can be visualized with an MRI. • They are better seen with the injection of contrast into the joint before the MRI evaluation. • Patients older than 45 years tend to tear the rotator cuff tendons when the shoulder is dislocated. • The tendons are less elastic and do not stretch out during the incident and thus tear

22. Procedures • The most important treatment of an acute shoulder dislocation is prompt reduction of the glenohumeraljoint • Numerous reduction techniques have been described that can be performed after administering an intra-articular injection or after putting the patient under conscious sedation. After determining the direction of the dislocation, the physician must remember that the most important aspect of reduction is relaxation of the shoulder musculature. Once reduction has been accomplished, postreduction radiographs are necessary to verify reduction.

23. Shoulder reduction techniques are as follows: • For the more common anterior dislocations, one of the oldest methods of reduction is the Hippocratic method, in which the physician's foot is placed in the patient's axilla while gentle longitudinal traction is applied. Internal or external rotation of the shoulder may facilitate reduction. • The Stimson technique involves having the patient lie prone on an examining table, allowing the affected arm to hang off the bed. Again, longitudinal traction and internal or external rotation are applied to the arm. Weights can also be added to the patient's wrist to facilitate reduction. • The Milch maneuver is one in which abduction and external rotation are applied to the affected extremity while the physician's thumb disengages the humeral head. This technique can also be attempted with the patient in the prone position. • Finally, one of the simplest maneuvers is passive forward elevation of the arm while the physician maneuvers the humeral head with the opposite hand.

26. Post-reduction: immobilisation in external versus internal rotation • For thousands of years, treatment of anterior shoulder dislocation has included immobilisation of the patient's arm in a sling, with the arm placed in internal rotation (across the body). • However, three studies, one in cadavers and two in patients, suggest that the detachment of the structures in the front of the shoulder is made worse when the shoulder is placed in internal rotation to be seen. • By contrast, the structures are realigned when the arm is placed in external rotation. • New data suggest that if the shoulder is managed non-operatively and immobilised, it should be immobilised in a position of external rotation. • Another study found that conventional shoulder immobilisation in a sling offered no benefit.

27. Complications • The most common complication of an acute shoulder dislocation is recurrence. • This complication occurs because the capsule and surrounding ligaments are stretched and deformed during the dislocation. Age is the most important indicator for prognosis; dislocations recur in approximately 90% of teenagers. • Another common complication following dislocation is fracture. • The most common type is a Hill-Sachs lesion or compression fracture of the posterior humeral head. • Fractures of the proximal humerus, greater tuberosity, coracoid, and acromion have also been described.

28. Complications • Rotator cuff tears also commonly occur as a result of shoulder dislocations, and the frequency of this complication increases with age. • This complication can be expected in 30-35% of patients aged 40 years or older. Slow progression in return to active function following shoulder dislocation in a middle-aged patient should warrant a workup for a rotator cuff tear. • Vascular injuries are rare, but they do occur, especially in older patients. Vascular injuries are more common with inferior dislocations and usually involve a branch of the axillary artery. • Nerve injuries are much more common than vascular injuries, especially with anterior or inferior dislocations. The axillary nerve is the nerve injured most often and may be crushed between the humeral head and the axillary border of the scapula or injured by traction from the humeral head. Axillary nerve injury has been reported in as many as 33% of acute anterior dislocation

29. Prognosis • Age at dislocation is the most important prognostic indicator for recurrence of shoulder dislocations. • Younger age at initial injury increases the likelihood for future dislocation. • The recurrence rate is thought to be 90% if the initial episode occurs in the teen years. • In patients aged 40 years or older, the recurrence rate is 10-15%. Most redislocations occur within 2 years of the primary injury. • Persons with axillary nerve injuries can be expected to recover completely within 3-6 months.

30. Rehabilitation • In the acute phase of a dislocated shoulder, therapy should be limited. • The arm should be immobilized in a sling and swathed for 1-3 weeks. • The actual position of the arm in the sling has been debated and thought to be more beneficial to the torn soft tissues with the arm in external rotation • Recent literature has shown that having the arm in internal rotation while in the sling has no impact on the rate of recurrent dislocation when compared with patients immobilized in external rotation. • While the patient is in the sling, elbow, wrist, and hand range of motion should be encouraged. • Working with the parascapular muscles is also important during this acute phase of rehabilitation since these can be initiated while the patient is still in the sling. These exercises should be continued when the patient comes out of the sling.

31. Prevention • Strong shoulder muscles remain the best defense against shoulder dislocation, subluxation, and, thus, instability. • Exercises that build up these muscles around the shoulder should be done. • The key is to balance the muscles around the shoulder and ensure not only the 'mirror' muscles are exercises (those that you can see when looking in the mirror). • Good core stability and posture are also important. • Adequate warm-up before activity and avoidance of high-contact sports will help prevent instability-causing injuries.

32. Rehabilitation • Active and passive flexion, extension, abduction and internal/external rotation begin at about the third week, when the patient comes out of the sling. • Encourage patients to get about 10 degrees of improvement in their motion per week. • It is important to educate the patient and inform him or her that getting all of the motion back "right away" can be detrimental to the stability of their shoulder. • Rehabilitation should be geared to gently restoring the range of motion over 6-8 weeks.

35. Rehabilitation • A good adage during the first 3 weeks after a shoulder dislocation is to "keep the hand in view." • While looking forward, the patient should never let his or her hand be placed in a position outside the line of vision. • This instruction assures a midrange position that does not compromise apposition of the torn or stretched anterior capsular structures to the glenoid.

37. Recovery Phase • After the initial period of immobilization, passive ROM exercises should begin. • Older individuals should begin performing ROM of the shoulder after 1 week of immobilization, because these patients are prone to shoulder stiffness. • Passive ROM exercises should include shoulder pendulum exercises and an overhead pulley system for the shoulder. • Goals for passive ROM should be 30° of external rotation and 90° of flexion for the first 3 weeks, followed by 40° of external rotation and 140° of flexion for the second 3 weeks. • The rotator cuff may also have been injured during the dislocation, so the therapist should be cognizant of the status of the rotator cuff during the early phase of rehabilitation.

38. Surgical Intervention • The recurrence rate for shoulder instability is highly dependent on the age of the patient. • Nonoperativecare should be performed first before entertaining the thought of surgery. • Most patients are able to rehabilitate their shoulder with rest and physical therapy. • In patients who have recurrent shoulder instability, operative care should be highly considered. • Numerous studies have shown the increased likelihood of traumatic glenohumeral arthritis in patients with multiple shoulder dislocations. • Operative care may consist of both open or arthroscopic treatment of the cause of instability.

39. Surgical Intervention • Athletes who demonstrate symptomatic instability during guarded physical therapy should be considered for an MRI evaluation and probable arthroscopic or open anterior shoulder tissue repair.

40. Maintenance Phase • More vigorous therapy can be initiated after full passive ROM has been regained, usually after 6 weeks. • Rotator cuff strengthening exercises can be initiated with the use of rubber tubing or weights. • Because the rate of shoulder redislocation is so much higher in young adults, vigorous training and strengthening should be delayed until approximately 3 months after the injury. • Swimming is an ideal exercise to regain shoulder strength and should be encouraged once strengthening exercises have begun.

41. Medication • Shoulder dislocations are extremely painful events. • If relocation is not accomplished within an hour, anesthesia via conscious sedation is necessary in the emergency department setting. • Oral narcotic analgesics are reasonable for a period of days, but prolonged use is categorically inappropriate.

42. Return to Play? • Return to play in patients following a shoulder dislocation is determined when full ROM and strength have been regained. • Return to play is usually sooner for older adults than for younger athletes, because the fear of redislocation is much lower in older adults. • Usually, older adults can return to play within 3 months. • With younger adults, conditioning can continue through shoulder rehabilitation; however, decisions about returning to play should be more conservative than those in older adults. • Absolute criteria are full ROM and full strength.

43. When determining a patient's return to competitive sports, the author uses the following criteria: • Scapular stability through full ROM • Normal scapulohumeral rhythm • Full active and passive ROM • Rotator cuff strength at 80% of opposite side • Pain-free activities of daily living (ADLs)