Cases of shoulder joint dislocation commonly present with severe pain and poor range of motion at the shoulder in addition to dislocation of the joint. 

Anterior dislocation

• Arm is abducted and externally rotated
• Head of humerus may be palpable on the anterior surface of the joint
• Void visualized on the posterior surface of the joint

Posterior dislocation

• Easily missed on physical exam since the arm is held in adduction and internal rotation
• Head of humerus may be visualized or palpated on the posterior surface of the joint
• Diagnosis assisted by radiographic evaluation 

It is essential to perform neurovascular examination and document the findings at the time of presentation and after reduction of the anomaly, both, in order to look for axillary nerve injury, since it occurs in almost 40% of the cases. 

• Falling

  In traumatic posterior dislocations, the injury is almost always due to a fall onto an outstretched, internally rotated arm. The force of the impact pushes the head of the humerus posteriorly out of the glenoid cavity. [lifeinthefastlane.com]

  Shoulder dislocations are common for athletes in contact sports or sports that can involve lots of falling, such as gymnastics. Shoulder dislocations are also common to other accidents, such as car crashes and falls. [childrenshospital.org]

  Sub- glenoid, sub clavicular, and, very rarely, intrathoracic or retroperitoneal dislocations may also occur. [7] Anterior dislocations are usually caused by a direct blow to, or fall on, an outstretched arm. [en.wikipedia.org]

  A 46-year-old man was admitted to our hospital with acute posterior shoulder dislocation due to a fall experienced while inebriated. [ncbi.nlm.nih.gov]

• Arm Pain

  This can lead to a loss of sensation and muscle strength in the affected arm. Pain relieving medication prescribed by a doctor can help to relieve the shoulder pain. [physioroom.com]

  A shoulder dislocation is usually associated with extreme pain and an inability to move your arm until it is relocated back into the socket. [physioworks.com.au]

• Ecchymosis

  If a fracture is suspected (eg, crepitus on palpation, immediate swelling, or ecchymosis), then reduction attempts should not be performed before obtaining radiographs. [chiro.org]

• Aspiration

  Definitive therapy involved hemarthrosis aspiration. Others have reported spontaneous hemarthrosis due to anticoagulants; however, only 1 has reported an initial mistaken joint dislocation diagnosis. [ncbi.nlm.nih.gov]

  If any blood is aspirated from the joint, hold the needle hub motionless, switch to an empty syringe, aspirate all of the blood, and re-attach the anesthetic syringe. Inject 10 to 20 mL of anesthetic solution (eg, 1% lidocaine). [msdmanuals.com]

• Overeating

  Early MRI has been recommended in patients older than 40 years, given the 35% prevalence of rotator cuff tears in this population, with an increase over time to over 80% after 60 years of age [ 21 ]. [em-consulte.com]

  The patients were divided into three groups by the age at the first dislocation and the surgical treatment: group A (onset and treatment were at an age over 40 years), group B (onset was at an age under 40 years and treatment was at an age over 40 years [ncbi.nlm.nih.gov]

  Sometimes a bone, usually the top of the arm bone, is broken, especially in people over 45. [msdmanuals.com]

• Sweating

  Stafylakis D, Abrassart S, Hoffmeyer P: Reducing a shoulder dislocation without sweating: The Davos technique and its results: Evaluation of a nontraumatic, safe, and simple technique for reducing anterior shoulder dislocations. [msdmanuals.com]

  A breathable material is ideal, so your choice won’t chafe or cause sweating as you recover. [vivehealth.com]

  Sweating dysfunction in Parkinson’s disease. Mov Disord. 2003;18(12):1459-63. 399 - Eadie MJ, Tyrer JH. Alimentary disorder in Parkinsonism. Australas Ann Med. 1965;14:13-22. 400 - Edwards LL, Pfeiffer RF, Quigley EM, Hofman R, Balluff M. [richtlijnendatabase.nl]

• Shoulder Pain

  After 4 weeks of physical therapy, the patient's shoulder pain had reduced and the passive ROM was nearly full. At 1-year follow-up, only mild intermittent shoulder pain was noted, and there was no limitation of shoulder ROM. [ncbi.nlm.nih.gov]

  […] dislocation in patients with indirect trauma and the arm flexed at the shoulder in adduction and internal rotation, or those with shoulder pain after a seizure or electrocution •Request radiography of the shoulder with two orthogonal views, anterioposterior [bmj.com]

  Shoulder dislocations are characterised by severe shoulder pain and hospital treatment is required to restore normal shoulder anatomy. [physioroom.com]

• Joint Dislocation

  Half of all cases with major joint dislocations are those with shoulder joint dislocation. [symptoma.com]

  Others have reported spontaneous hemarthrosis due to anticoagulants; however, only 1 has reported an initial mistaken joint dislocation diagnosis. [ncbi.nlm.nih.gov]

  The shoulder joint is the most frequently dislocated major joint of the body. [news-medical.net]

  Anterior shoulder dislocation accounts for the majority of joint dislocations seen in the emergency department. The diagnosis of dislocation is based on a number of factors, including pain and range of movement of the afflicted joint. [nejm.org]

• Left Shoulder Pain

  shoulder pain, limited abduction, and arm held in slight internal rotation, with a flexed, adducted, and internally rotated position (fig 1⇓). [bmj.com]

  Case presentation - We present a 5-year-old male who presented to the office with post-traumatic left shoulder pain for about 1 week. Radiographs of the left shoulder indicated inferior subluxation of the humeral head. [ncbi.nlm.nih.gov]

  Subscribers only (OBQ06.15) A 63-year-old diabetic female complains of left shoulder pain and decreased range of motion 7 months after a fall onto her left side. [orthobullets.com]

  On exam, her left arm is adducted and internally rotated. Her range of motion is limited due to pain. An axillary lateral radiograph demonstrates a posterior shoulder dislocation. [step2.medbullets.com]

• Right Shoulder Pain

  We report a case of a 37-year-old man who presented to the emergency department with severe right shoulder pain and inability to move his arm after a motor vehicle collision. [ncbi.nlm.nih.gov]

  Tips on using this imaging technique for the emergency physician Clinical Case A 28-year-old male presents to the ED with moderate to severe right shoulder pain. [acepnow.com]

  […] of heavy drinking with severe right shoulder pain and inability to raise his arm above his head. [orthobullets.com]

• Stiffness of the Shoulder

  If your shoulder does not gain range of motion as we would expect, and remains very stiff, we will liaise with your surgeon immediately. [humpalphysicaltherapy.com]

• Suggestibility

  Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. [ncbi.nlm.nih.gov]

  Arthroscopic lavage has been suggested to eliminate the haemarthrosis and promote normal positioning of the capsule-labral complex on the glenoid [ 56 ]. [em-consulte.com]

  There was no significant difference between patients who had surgery and those who didn't, suggesting fewer patients require a surgical procedure to fix the injury. [upi.com]

• Distractibility

  In a traumatic setting, a shoulder dislocation may be accompanied by a distracting injury, and a thorough examination must be conducted to avoid overlooking concomitant diagnosis. [ncbi.nlm.nih.gov]

  Reduction techniques must distract the humeral head away from the lip and then return the humeral head into the fossa. Deficits of the axillary nerve are the most frequent nerve deficits with anterior shoulder dislocations. [msdmanuals.com]

• Seizure

  Non epileptic seizures such as drug withdrawal or hypoglycaemia should also be considered. [lifeinthefastlane.com]

  Besides seizures, the nerves can also be damaged by anticonvulsive therapy. Muscle wasting following a seizure can misguide a clinician to investigate only neural or muscular pathologies. [ncbi.nlm.nih.gov]

• Irritability

  This can cause pain irritation of the soft tissues around the shoulder and often prevents sufferers from carrying out their full range of activities. [ebtc.ie]

  Always wrap ice in a thin cloth, towel or plastic bag before applying it to bare skin — it'll help prevent frostbite or skin irritation. [wikihow.com]

  It is important that the patient be aware of the possible side effects of these medications, including stomach irritation, kidney problems and bleeding. [orthop.washington.edu]

• Headache

  IVAS was associated with higher risks of respiratory depression (P < 0.0001), vomiting (P = 0.04), and thrombophlebitis (P = 0.008), but no statistical differences were identified in nausea (P = 0.06), hypotension (P = 0.10), drowsiness (P = 0.45), or headache [ncbi.nlm.nih.gov]

X-ray films, antero-posterior and lateral with/without axillary view are sufficient in most cases to reach a diagnosis. The outline of the glenoid fossa and the humeral head are incongruent in X-rays for anterior dislocation and also inferior dislocation of the shoulder. Posterior dislocations are challenging to identify on antero-posterior view since the congruency does not appear to be disrupted, as the head of humerus moved directly to the posterior position. It can be easily diagnosed using the axillary/ trans-scapular Y view, where the malalignment of the humerus is clearly visualized. Therefore, it is recommended that the trans-scapular Y view should be ordered routinely in all cases with suspected shoulder joint dislocation.

Additional diagnostic tests include:

• MRI: Used when tendon/ligament fractures are suspected. Contrast agent may be used for obtaining better images.
• CT scan: Employed when minor fractures that can be missed on a X Ray are suspected, such as glenoid rim fracture.

All acute cases of shoulder dislocation require immediate reduction of the joint [1] [5] [16]. The goal of reduction is relaxation of shoulder muscles. Once the appropriate direction of the anomaly has been determined, conscious sedation or an intra-articular analgesic may be administered prior to the reduction procedure. In order to verify the reduction, radiographs must be obtained after the procedure has been completed. Methods to achieve reduction include:

Physical therapy

There should be limited use of physical therapy in an acute case. One to three weeks of sling immobilization and swathing of the arm in externally rotated position is advised, as it is thought to the benefit the torn soft tissues [16] [17] [18] [19]. The movement of fingers, hand, elbow and wrist of the arm in sling, along with the movement of parascapular muscles should be encouraged to begin early rehabilitation, and must be continued after the sling has been discontinued.

Surgery

Surgery must be considered in all cases presenting with recurrent instability of the shoulder joint [3] [5] [6]. The operative intervention aims at reattachment of the torn tissues to their site of attachment at the bone. The most common site for a tear in the ligament is at the glenoid. Ligaments may get stretched secondary to recurrent shoulder dislocations, therefore making it necessary to correct any laxity in the tissues intra-operatively. The procedure is usually performed by arthroscopy, but an open incision may also be used.

Anterior dislocation

It is commonly managed by closed reduction under conscious sedation or intra-articular block. The following techniques can be used for reduction:

•  Traction-countertraction
•  Scapular manipulation
•  External rotation techniques, such as Hennepin technique 
•  Cunningham technique

Posterior dislocation

Posterior dislocation is usually reduced by longitudinal traction.

Inferior dislocation

Reduction of the joint is achieved by applying traction-countertraction to the abducted arm. A closed reduction will not be successful if the head of humerus is trapped within a torn inferior capsule (also called as buttonhole deformity), and such circumstances will warrant an open reduction.

Dislocation is mostly managed with relocation. If the duration between dislocation and relocation is short, the risk of complications will be less. The next step in treatment is immobilization of the joint for 7-10 days in patients older than 30 years and 3 weeks for patients less than 30 years. This period should involve keeping the joints of the arm, wrist and fingers active to maintain range of motion [7]. 

Young patients may benefit from early intervention with arthroscopy, labral repair and debridement, since cases of a younger age group with anterior dislocation of the shoulder joint have a recurrence rate of 85% [20]. There is limited evidence supporting primary surgical correction for young adults that engage in intensive physical activities, but none for other age groups or types of injuries.

The age of the patient is considered as the most significant factor to assess the risk for re-dislocation of the shoulder joint. The risk is higher for individuals that sustained the first dislocation of the shoulder at a younger age, with the rate of recurrence being almost 90% in cases that had the first dislocation in teenage. The rate of recurrence falls to 10-15% in cases forty years old and older. The re-dislocation frequently occurs with a period of two years of the first dislocation.

Although the arthroscopic procedure for the repair of shoulder dislocation, called the Bankart repair (ABR), is an effective modality, re-injuring the same joint with the arm in 90° elevation and 90° external rotation within a year of the procedure was found to be a major risk factor for re-dislocation. It was also found that having less than four suture anchors and large Hill Sachs lesions considerably increased the risk for a re-dislocation after the procedure.

In patients with anterior dislocation of the shoulder, a primary non-operative treatment is usually followed by recurring deficits in the function of the joint. Young males have been found to have the greatest risk for joint instability while females have a considerably lower risk. Clinical trials, using novel tools to determine the prevalence of functional deficits and recurring instability in shoulder joint, may be considered for a follow-up period of two years after primary dislocation of the joint.

The axillary nerve is frequently injured in association with dislocation of the shoulder joint. It courses inferior to the head of humerus and distally wraps around the surgical neck of humerus. If injured, a complete recovery of the nerve injury occurs within 3-6 months after resolution of the joint dislocation.

The shoulder joint is stabilized by the rotator cuff muscles, glenohumeral ligaments, negative intra-articular pressure, joint capsule and the bony/cartilaginous anatomy. Although there are multiple ligaments that contribute to the stabilization of the shoulder joint, the most significant of all is the inferior glenohumeral ligament. It is commonly injured when the shoulder dislocates anteriorly. Typically, there is a stretch injury of the capsule/ligament and/or tearing of the capsule/ligament where it attaches to the bone. 

Sport-specific bio-mechanics

During sports activities, the shoulder joint is quite often in an unusual position such as abduction and external rotation. This makes the ligaments vulnerable to injury from a fall or direct impact on the shoulder. Depending upon the strength of the force, there can be a fracture of the humerus or glenoid and/or the tendons/ligaments may get torn, leading to dislocation of the shoulder joint.

Major traumatic episodes are responsible for 95% cases of shoulder dislocation. In order to identify the etiology of dislocation, the severity and type of trauma has to be precisely determined. This in-turn is necessary for initiating appropriate treatment [1] [3] [4] [5] [6].

Anterior dislocations

95% cases of shoulder dislocation have anterior displacement of the joint. It occurs by abduction and external rotation along with trauma to surrounding structures, such as rotator cuff tear (especially in elderly), injury to the brachial plexus, greater tuberosity fracture and injury to the axillary nerve. Individuals less than 30 years of age commonly have shoulder joint instability, thus predisposing them to recurrent dislocation of the joint.

Posterior dislocations

Posterior dislocations are frequently missed. The most common causes for posterior dislocation of the shoulder joint include electro-convulsive therapy (if performed without concurrent use of muscle relaxants), electric shock or seizures. The deformity due to this dislocation may not be apparent. The patient presents with the arm held in adduction and internal rotation, and passive external rotation is not possible upon flexion of the elbow. If the latter sign is present, an antero-posterior X-Ray of the shoulder must be ordered.

Inferior dislocations/Luxatio erecta

This is the rarest of the three types of shoulder dislocations. Inferior dislocation may result from a forced hyperabduction [7]. The patient presents with the arm held above the head, often resting on it, with almost 180 degrees abduction. On physical examination, the head of the humerus is palpable in the axilla, the arm appears shortened, the rotator cuff may be torn and the joint capsule may be disrupted. Injury to the brachial artery is found in less than 5% of cases. Nerve injury,  often involving the axillary nerve, is usually present but resolve spontaneously after reducing the joint.

As we look at the numeric data for cases with dislocation of a major joint, shoulder joint dislocations contribute close to half of this number [8] [9] [10] [11] [12]. 95-97% of cases present with anterior dislocation of the shoulder joint, another 2-4% with posterior dislocation, and approximately 0.5% with inferior dislocation [13].

United States

The most frequently dislocated joint in human body is the shoulder joint [1] [3] [14]. The majority of cases have anterior dislocation, but a small fraction of cases also present with posterior, inferior and antero-superior dislocation of the shoulder. Cases with a history of shoulder dislocation are at a greater risk for another dislocation. This may be attributed to tissue laxity and/or poor healing. Other factors include concurrent tearing of the rotator cuff, glenoid fracture and advanced age of the patient.

Patients in their twenties and teenagers have a greater frequency of sustaining shoulder re-dislocation as compared to individuals aged fifties to sixties [15], which may be secondary to a higher activity level in the former group. These findings suggest that age may not be a significant risk factor for re-dislocation of the shoulder joint.

The shoulder joint is very mobile. It is stabilized by the rotator cuff muscles, glenohumeral joint capsule and the glenoid labrum. Shoulder joint instability can also occur due to tearing of the rotator cuff muscles, namely supraspinatus, infraspinatus, teres minor and subcapsularis. These muscles are located on the top of shoulder joint bones and the glenohumeral ligaments. Shoulder joint instability can occur due to large rotator cuff tears, even if the glenohumeral ligaments are intact. The joint can also become unstable if the nerves (especially the axillary nerve) innervating the shoulder muscles are injured.

Atraumatic dislocation of the shoulder joint can occur due to several reasons. Laxity of the ligaments in the shoulder joint may lead to atraumatic dislocation. Although the ligament laxity is bilateral, these patients may present with unilateral symptoms. Excessive retroversion of the humeral head and glenoid malformation are congenital deformities that can cause shoulder joint instability. Axillary nerve injury and cerebral palsy have also been associated with instability of the shoulder joint.

The bio-mechanical forces that can lead to dislocation of the shoulder include [2]:

• Forced extension, abduction and external rotation: Causes anterior dislocation of the shoulder joint, most common cause for shoulder dislocation
• Direct blow on the shoulder from behind: Causes anterior dislocation of the shoulder joint
• Forceful contraction of shoulder girdle muscles: Rare cause for shoulder dislocations, causes posterior dislocation of the shoulder joint
• Forced hyperabduction [7]: Causes inferior dislocation of the shoulder joint

In order to avoid sustaining a dislocation of the shoulder, patients must refrain from immediate participation in strenuous sports activities. Any activity that puts the arm in abduction and external rotation, like combing of hair, must also be avoided.

Patients with dislocation of the shoulder joint account for almost half of the case number for all major joint dislocations. The dislocation of the shoulder joint may occur due to capsular ligament laxity or trauma to the joint. Various conditions may influence the joint stability and may lead to poor outcome in cases with dislocation of the shoulder joint [1].

The types of shoulder joint location are:

•  Anterior
•  Inferior
•  Posterior

The most common dislocation of the three types is anterior shoulder dislocation and is the result of forced abduction, external rotation and extension [2].

Half of all cases with major joint dislocations are those with shoulder joint dislocation. Almost 95-97% patients with shoulder dislocation have anterior dislocation of the joint another 2-4% have posterior dislocation and rarely, inferior dislocation. The shoulder joint is has a wide range of motion and therefore is relatively less stable and more prone to dislocation. Anterior dislocation of the shoulder is treated by performing maneuvers, followed by approximately six weeks of immobilization to allow healing of the structures that form the joint. A good physical therapy is the key to achieving normal function of the joint after injury. Isometric exercises are emphasized during the physical therapy, in order to allow sufficient rest to the glenohumeral joint for faster healing. Early surgical intervention may benefit younger patients who sustained anterior dislocation of the shoulder, since their chances of sustaining shoulder dislocation again are very high.

1. Matsen FA III, Thomas SC, Rockwood CA Jr. Anterior glenohumeral instability. Rockwood CA Jr, Matsen FA III, eds. The Shoulder. Philadelphia, Pa: WB Saunders Co; 1990. Vol 1: 526-622.
2. Manaster BJ, Disler DG, May DA et-al. Musculoskeletal imaging, the requisites. Mosby Inc. (2002) ISBN:0323011896.
3. Dodson CC, Cordasco FA. Anterior glenohumeral joint dislocations. Orthop Clin North Am. 2008 Oct. 39(4):507-18, vii.
4. Burkhead WZ Jr, Rockwood CA Jr. Treatment of instability of the shoulder with an exercise program. J Bone Joint Surg Am. 1992 Jul. 74(6):890-6.
5. Schenk TJ, Brems JJ. Multidirectional instability of the shoulder: pathophysiology, diagnosis, and management. J Am Acad Orthop Surg. 1998 Jan-Feb. 6(1):65-72.
6. Cox CL, Kuhn JE. Operative versus nonoperative treatment of acute shoulder dislocation in the athlete. Curr Sports Med Rep. 2008 Sep-Oct. 7(5):263-8.
7. Simon RR, Sherman SC, Koenigsknecht SJ. Emergency orthopedics, the extremities. McGraw-Hill Professional. (2007) ISBN:0071448314.
8. Simon RR, Sherman SC, Koenigsknecht SJ. Emergency Orthopedics: The Extremities, 5th, McGraw-Hill, New York 2006.
9. Schaider J, Simon RR. Shoulder injuries. In: Clinical Practice of Emergency Medicine, Wolfson AB, Hendey GW, Hendry PL, et al (Eds), Lippincott Williams & Wilkins, Philadelphia 2005. p.1033.
10. Sineff SS, Reichman EF. Shoulder joint dislocation reduction. In: Emergency Medicine Procedures, Reichman EF, Simon RR (Eds), McGraw-Hill, New York 2004. p.593.
11. Simonet WT, Melton LJ 3rd, Cofield RH, Ilstrup DM. Incidence of anterior shoulder dislocation in Olmsted County, Minnesota. Clin Orthop Relat Res 1984; :186.
12. Zacchilli MA, Owens BD. Epidemiology of shoulder dislocations presenting to emergency departments in the United States. J Bone Joint Surg Am 2010; 92:542.
13. Brady WJ, Knuth CJ, Pirrallo RG. Bilateral inferior glenohumeral dislocation: luxatio erecta, an unusual presentation of a rare disorder. J Emerg Med 1995; 13:37.
14. Blasier RB, Guldberg RE, Rothman ED. Anterior shoulder stability: Contributions of rotator cuff forces and the capsular ligaments in a cadaver model. J Shoulder Elbow Surg. 1992. 1:140-50.
15. Hovelius L, Augustini BG, Fredin H, et al. Primary anterior dislocation of the shoulder in young patients. A ten-year prospective study. J Bone Joint Surg Am. 1996 Nov. 78(11):1677-84.
16. Itoi E, Hatakeyama Y, Urayama M, Pradhan RL, Kido T, Sato K. Position of immobilization after dislocation of the shoulder. A cadaveric study. J Bone Joint Surg Am. 1999 Mar. 81(3):385-90.
17. Itoi E, Sashi R, Minagawa H, Shimizu T, Wakabayashi I, Sato K. Position of immobilization after dislocation of the glenohumeral joint. A study with use of magnetic resonance imaging. J Bone Joint Surg Am. 2001 May. 83-A(5):661-7.
18. Itoi E, Hatakeyama Y, Kido T, Sato T, Minagawa H, Wakabayashi I, et al. A new method of immobilization after traumatic anterior dislocation of the shoulder: a preliminary study. J Shoulder Elbow Surg. 2003 Sep-Oct. 12(5):413-5.
19. Itoi E, Hatakeyama Y, Sato T, Kido T, Minagawa H, Yamamoto N, et al. Immobilization in external rotation after shoulder dislocation reduces the risk of recurrence. A randomized controlled trial. J Bone Joint Surg Am. 2007 Oct. 89(10):2124-31.
20. Peterson L, Renström P. Sports injuries, their prevention and treatment. Informa HealthCare. (2001) ISBN:1853171190