Shoulder Dislocation Surgery 

Updated: Feb 13, 2019
Author: Scott Welsh, MD; Chief Editor: S Ashfaq Hasan, MD 

Overview

Background

Shoulder dislocations account for almost 50% of all joint dislocations. Most commonly, these dislocations are anterior (90-98%) and occur because of trauma. Most anterior dislocations are subcoracoid in location. Subglenoid, subclavicular, and, very rarely, intrathoracic or retroperitoneal dislocations may occur.

For patient education resources, see the Breaks, Fractures, and Dislocations Center, as well as Shoulder Dislocation.

Etiology

The usual mechanism of injury is extreme abduction, external rotation, extension, and a posterior directed force against the humerus. Forceful abduction or external rotation alone can also lead to dislocation (~30% of cases), as can a direct blow to the posterior humerus (29%), forced elevation and external rotation (24%), and a fall onto an outstretched hand (17%).[1, 2]

Posterior dislocations are less common (2-10%) and result from the application of an axial load to the adducted and internally rotated arm. Classic posterior dislocations also occur as a result of electrocution or seizures because of the strength imbalance between the internal rotators (subscapularis, latissimus dorsi, and pectoralis major muscles), which overpower the external rotators (teres minor and infraspinatus muscles).

Inferior dislocations are rare and result from a hyperabduction force that causes the humeral neck to lever against the acromion. Diagnosing inferior dislocations is critical because of the high incidence of complications. Neurologic injuries (particularly axillary nerve lesions) are associated with inferior dislocations in as many as 60% of cases, vascular injuries occur in about 3.3% of cases, rotator cuff tears occur in 80-100% of cases,[3] and greater tuberosity fractures and pectoralis major avulsions are also associated with inferior dislocations.

Superior dislocations are extremely rare and result from an extreme force in a cephalic direction to the adducted arm. Acromioclavicular injuries and fractures of the acromion, clavicle, and tuberosities may occur with superior dislocations.

Atraumatic instability is usually multidirectional and commonly occurs in individuals with generalized hyperlaxity due to connective tissue disorders, such as Ehlers-Danlos syndrome and Marfan syndrome. A small or flat glenoid fossa, excessive anteversion or retroversion of the glenoid, weak rotator cuff muscles, neuromuscular disorders, or a redundant capsule may also jeopardize the concavity-compression, adhesion-cohesion, or the glenoid suction-cup phenomena that aid in stability of the shoulder.

Multidirectional instability most commonly occurs in younger populations (usually < 30 years) and is often familial and bilateral. The first dislocation often occurs after a minor injury or after a period of disuse. Patients may experience subluxations that progress over time to actual dislocations, which spontaneously reduce. These dislocations may be voluntary or involuntary. Voluntary dislocations have been associated with psychiatric illnesses and may be used in attention-seeking behavior. Surgery should be avoided in this population because the instability is likely to recur.

Prognosis

According to Scheibel et al, immobilization of the shoulder in 30º of external rotation seems to allow a similar coaptation of the glenoid labrum, regardless of whether immobilization is for 3 weeks or 5 weeks.[4] The authors divided 22 patients into two groups: 11 patients immobilized for 3 weeks and 11 patients immobilized for 5 weeks in 30º of external rotation. No statistically significant differences were found after acute, 3-week, and 5-week magnetic resonance imaging examinations.

In a study by Owens et al, acute arthroscopic Bankart repair in young, active patients with first-time traumatic anterior glenohumeral dislocations resulted in excellent subjective function and return to athletics, with an acceptable rate of recurrence and reoperation.[5] Of 39 patients followed (40 shoulders), six patients sustained recurrent dislocations, nine had subluxation events, and six underwent revision stabilization surgery.

Maier et al compared the clinical benefit of operative stabilization in younger patients (49 patients < 40 years) and older patients (23 patients >40 years) after anterior shoulder dislocation and found that there was significant reduction in recurrence in both groups.[6] However, the clinical functional results measured by the Constant score, Rowe score, and disabilities of the arm, shoulder, and hand (DASH) score revealed significantly better outcomes in the younger group.

In a study by Cordischi et al involving skeletally immature patients (14 patients aged 10.9-13.1 years) who sustained a primary traumatic unidirectional anterior shoulder dislocation, patients who were treated nonoperatively fared better than those treated by surgery (average Western Ontario Shoulder Instability index [WOSI] score of 9.1 vs 151.7, respectively).[7] According to the authors, in the pediatric skeletally immature patient, nonoperative treatment results in low shoulder instability recurrence risk and sound functional outcome.

Abdelhady et al conducted a prospective study to assess the efficacy of the Latarjet procedure in patients with recurrent anterior shoulder dislocation and generalized hyperlaxity.[8]  Mean Rowe score was 47.5 points preoperatively and increased to 91.07 postoperatively; the increase was statistically highly significant. Mean range of postoperative external rotation was 69.29°. The investigators concluded that in these patients, the Latarjet procedure has a higher success rate than capsulolabral repair procedures.

Longo et al conducted a systematic review of the literature to evaluate clinical outcome, rate of recurrence, complications, and rate of postoperative osteoarthritis in patients with anterior shoulder instability managed with Latarjet, Bristow, or Eden-Hybinette procedures.[9]  The review included 46 studies, in which 3211 shoulders were evaluated. The mean value of the Coleman Methodology Score (CMS) was 65 points. Preoperatively, the most commonly detected injuries were glenoid bone loss and Bankart lesions.

The investigators concluded that the open Bristow-Latarjet procedure was a valid surgical option for treating anterior shoulder instability.[9]  Clinical outcomes associated with the Eden-Hybinette procedure were very similar to those of the Bristow-Latarjet technique, but the former was associated with a higher rate of postoperative osteoarthritis and recurrence. An arthroscopic Bristow-Latarjet procedure appeared to be better in terms of prevention of recurrence and rehabilitation, but further studies are needed to confirm this difference.

Blonna et al studied 60 patients with posttraumatic recurrent anterior shoulder instability that was treated either with the arthroscopic Bankart repair (n=30) or the open Bristow-Latarjet procedure (n=30).[10]  The primary outcomes were return to sport (Subjective Patient Outcome for Return to Sports [SPORTS] score), rate of recurrent instability, Oxford Shoulder Instability Score (OSIS), Subjective Shoulder Value (SSV), WOSI, and range of motion (ROM). After a mean follow-up of 5.3 years (range, 2-9), arthroscopic stabilization provided better return to sport and subjective perception of the shoulder than the open Bristow-Latarjet procedure.

Virk et al assessed the time to recurrence (TTR) of instability and disease-specific outcome measures in 80 patients (82 shoulders) with recurrent traumatic anterior shoulder instability and a Bankart lesion on diagnostic arthroscopy who underwent open (n=24) or arthroscopic (n=58) Bankart repair.[11]  The mean time to recurrence of postoperative instability was significantly shorter in the arthroscopic group than in the open group (12.6±2.7 months vs 34.2±12 months). The authors suggested that in view of the longer time to recurrence after open Bankart repair, this approach might be better suited to individuals in heavy-duty professions (contact athletes and workers who perform heavy manual labor).

 

Presentation

History and Physical Examination

Patients with anterior dislocations usually present with the arm in slight abduction and externally rotated. The humeral head can often be palpated in the front of the shoulder. Internal rotation and adduction are limited. Movement is usually very painful as a result of muscle spasms.

Patients with posterior dislocations present with the arm internally rotated and adducted. External rotation is severely limited. A posterior prominence is usually palpable, the anterior shoulder is flattened, and the coracoid process is more prominent. Historically, these dislocations have been missed or misdiagnosed as a frozen shoulder.

Inferior dislocations lead to a condition known as luxatio erecta, which describes a classic presentation of the arm abducted 110-160° with the forearm resting on or behind the patient's head.[12, 13]

 

Workup

Imaging Studies

Radiography

Conventional radiography should be performed in all patients with suspected shoulder dislocations to confirm the diagnosis and also to exclude associated fractures prior to any attempted reduction.[14] Routine radiographs should include at least an anteroposterior (AP) view and an axillary view.[15]

The AP view can be obtained in neutral, internal, or external rotation. In internal rotation, one can easily see a Hill-Sachs lesion of the posterolateral humeral head.

The axillary view nicely shows glenohumeral subluxation or dislocation, as well as anterior or posterior glenoid rim fractures.[16] A standard axillary view may be difficult in the acute injury setting because it requires 90° of abduction. However, many modifications exist to avoid excessive movement of the painful extremity. For example, the transverse axillary lateral requires the patient to abduct the arm only 10-30°.

Other views that may be useful include the scapular Y view, which is helpful for diagnosing dislocations and scapular fractures. This view, however, should not replace the axillary view, because it does not show subtle subluxations of the glenohumeral joint or fractures of the glenoid rim.

The true AP or Grashey view is helpful in assessing subtle joint incongruity, superior or inferior subluxation, degenerative changes, or glenoid hypoplasia.

The Garth or West Point view is useful in detecting bony Bankart fractures of the anteroinferior glenoid rim as well as Hill-Sachs defects. This view is advantageous in the acute setting because it does not necessitate the patient moving the arm.

The Stryker notch view can also be useful in detecting Hill-Sachs lesions. However, this view is of limited usefulness in detecting subluxations or glenoid fractures.

CT arthrography, MRI, and MR arthrography

Computed tomography (CT) arthrography, magnetic resonance imaging (MRI), or magnetic resonance arthrography may be helpful in assessing some shoulder dislocations.[17]

CT arthrography was commonly used in the past to evaluate patients with glenohumeral instability either after the initial dislocation or with recurrent instability. Currently, it is used only if MRI is contraindicated or if glenoid version abnormalities are suspected. Multidetector CT (MDCT) with three-dimensional (3D) volume rendering can be helpful in further characterization of osseous abnormalities.[18]

MRI and magnetic resonance (MR) arthrography have been shown to be more sensitive than other methods in detecting labral and ligamentous pathology, rotator cuff and cartilage tears, capsular abnormalities, and biceps injuries. MR arthrography is more sensitive than MRI alone and is the study of choice after a shoulder dislocation, particularly in cases of recurrent instability. In addition, it is superior to MRI for diagnosing the pathologic lesions mentioned above.

 

Treatment

Approach Considerations

Surgery for shoulder dislocation may be indicated if patients are unable or unwilling to change their occupation or avoid participating in high-risk sports and if they have recurrent dislocations or subluxations. Surgery should be avoided in patients with voluntary shoulder dislocations associated with psychiatric illnesses because the instability is likely to recur.

Medical Therapy

Closed reduction

Many methods can be used to reduce a shoulder dislocation, but the most important factor for a successful reduction is time to reduction.[19] As time passes, the muscles become more spastic, and the reduction becomes significantly more difficult.[20] Methods of reduction include the following:

  • Hippocratic method
  • Kocher method
  • External rotation
  • Stimson technique
  • Milch technique
  • Scapular manipulation
  • Spaso technique
  • Traction-countertraction
  • Axial (inline) traction
  • Two-step method

The Hippocratic method involves longitudinal traction on the arm and a counterforce to the axilla, usually with the heel of the foot.

The Kocher method involves traction to the elbow with external rotation of the humerus and adducting the elbow toward the chest. This method is not currently recommended because of its association with neurovascular complications and proximal humerus fractures.

The external rotation method, which is a modification of the Kocher maneuver, involves flexing the elbow to 90° and slowly adducting the arm to the patient's side. The arm is then carefully externally rotated stopping every few degrees to wait for the muscle spasms to subside.

The Stimson technique requires the patient to be positioned prone. The patient's arm is allowed to hang over the edge of the bed with about 10 pounds of weight hanging from the wrist.

The Milch technique is very successful and relatively atraumatic. It involves the surgeon abducting the patient's arm with one hand while applying pressure to the humeral head with the other hand. When the patient's arm is fully abducted, external rotation and traction are applied. The success rate of this technique is 72-89%. Only about one third of patients require sedation or analgesia. Lacey et al modified this technique by performing the Milch maneuver with the patient in the prone position.

Scapular manipulation is also relatively atraumatic and incorporates internal rotation of the scapula to disengage the humeral head. The patient is placed prone and 5-15 pounds of traction are applied to the forearm. The inferior angle of the scapula is then rotated medially, and the superior aspect is rotated laterally. The success rate is 92-96%.

The Spaso technique involves the use of vertical traction while the surgeon grasps the wrist or forearm with the patient supine.[21, 22] Traction is maintained as the shoulder is externally rotated. The opposite hand may be used to push posteriorly on the head. Continual traction for several minutes will often overcome the spastic rotator cuff muscles, which are more relaxed with the arm in a forward-flexed position (roughly 90°). The success rate is 87.5%.

Traction-countertraction is the method preferred by many authors. This method involves the application of longitudinal traction in the direction of the deformity and countertraction by using a sheet wrapped around the patient's chest. The shoulder is gently rotated internally and externally to disengage the head from the glenoid.

Axial (inline) traction and the two-step method are commonly used to reduce inferior shoulder dislocations. (See Reduction of Shoulder Dislocation.)

Sedation and analgesia

Many options are available to achieve the patient's maximum comfort and to increase the ease of the reduction. If a dislocation is identified early, reduction may be achieved without the use of narcotics, sedatives, or muscle relaxants, particularly when the scapular manipulation technique is used.[23]

More commonly, however, some type of analgesic is combined with a sedative or muscle relaxant. Morphine or fentanyl is generally administered on the patient's arrival in the emergency department. A sedative such as midazolam or etomidate is subsequently used to achieve reduction. Etomidate has become a popular choice because of its rapid onset (< 30 s) and short duration of effects (< 5 min). It also provides excellent muscle relaxation and is more predictable than midazolam. Typically, a narcotic analgesic is administered before etomidate because etomidate has no analgesic properties.

Another alternative is the intra-articular administration of lidocaine. Usually, about 20 mL of 1% lidocaine without epinephrine is injected with a 1.5-in. 20-gauge needle about 2 cm lateral and inferior (or posterolateral) to the acromion. The needle is directed toward the glenoid in a slightly caudal direction. This method has been compared with intravenous sedation and found to be as effective for pain control and ease of reduction. Intra-articular lidocaine has been shown to be as successful or slightly less effective in achieving reduction, primarily in cases of delayed (>5.5 hours) presentation.[24]

Conservative treatment

Conservative treatment of shoulder dislocations remains a controversial topic in orthopedics.[25] Traditionally, patients have been placed in a sling with or without an immobilizer strap for a period of 1-6 weeks. Internal rotation and adduction is the classic position of immobilization, and external rotation and abduction are avoided.

Two studies by Itoi et al shed light on this topic.[17, 26] A magnetic resonance imaging (MRI) study showed the best coaptation of the anteroinferior glenoid labrum to the glenoid rim to be with the arm in about 35° of external rotation and held at the patient's side.[17] Another study in cadavers revealed that there is a range from full internal rotation to about 30° of external rotation in which the labrum is coapted to the glenoid when the arm is in slight adduction.[26] Flexion or abduction tends to displace the labrum. Despite these findings, the position of mobilization remains in slight internal rotation to prevent recurrent dislocations.

The duration of immobilization has also been a subject of debate. Most authors have recommended 3-4 weeks of immobilization in patients younger than 30 years and 7-10 days of immobilization in those older than 30-40 years.[27] However, one study showed a significant reduction in recurrence (from 78% to 44% at 1 year and from 85% to 69% at 2 years) if the arm was immobilized for 4-7 weeks instead of 0-3 weeks.[28] The recurrence-free period was also extended from 4 months to 14 months with longer treatment.

On the other hand, Hovelius et al performed a prospective, randomized trial with 10-year follow-up and found that the duration of immobilization had no effect on the long-term recurrence rate.[29]

A prospective study by Finestone et al in patients who had experienced primary traumatic anterior shoulder dislocation found no difference in outcome with shoulder immobilization in external vs internal rotation.[30] Of the 51 patients, 24 received a traditional brace with the shoulder in internal rotation and 27 were immobilized with the shoulder in external rotation of 15-20º. After a mean of 33.4 months, 37% of patients in the external-rotation group and 41.7% of those in the internal-rotation group had sustained a further dislocation, a statistically insignificant difference.

Rehabilitation usually begins after 3 weeks of immobilization, starting with active assisted range of motion (ROM) with external rotation limited to 20°, pendulum exercises, and scapular retractions beginning 4-6 weeks after injury. Beginning 7-8 weeks after injury, active ROM exercises are prescribed, with external rotation limited to 45°, isometric cuff strengthening, and scapular exercises and retraining. Active ROM with terminal stretch, isotonics, and scapular strengthening is performed 9-12 weeks after injury.

Patients may return to noncontact sports with no overhead requirements after 3 months. Athletes may return to contact and overhead sports after 4 months. The success of this regimen largely depends on the patient's age at the time of the initial dislocation.

Greater tuberosity fractures associated with dislocation and advanced age are good prognostic indicators for successful nonoperative treatment. Activity modification (eg, avoiding overhead work, heavy manual labor, and high-risk sports) can minimize the risk of future dislocations.

Recurrence after nonoperative treatment

Nonathletes have a 30% recurrence risk with nonoperative treatment, and athletes have an 82% recurrence risk with nonoperative treatment.[31]

If the dislocation was the patient's first, recurrence rates with nonoperative treatment depend on age, as follows:

  • Patients aged 1-10 years have a 100% recurrence rate
  • Patients aged 11-20 years have a 27-95% recurrence rate
  • Patients aged 21-30 years have a 40-79% recurrence rate
  • Patients aged 31-40 years have a 40-72% recurrence rate
  • Patients aged 41-50 years have a 0-24% recurrence rate

Using the Western Ontario Shoulder Instability Index (WOSI) and the limb-specific Disabilities of the Arm, Shoulder and Hand score (DASH), a retrospective review study assessed the functional outcome of patients during the 2 years after a posterior glenohumeral dislocation.[32] The study noted that whereas the prevalence of posterior dislocation is low, the most common complication is recurrent instability. Factors putting these patients at highest risk for recurrent instability were as follows:

  • Age younger than 40 years
  • Dislocation during a seizure
  • Large humeral head defect

Most patients who sustain the injury from a traumatic accident, those who are older, and those with a small anterior humeral head defect realize a lower risk of recurrent instability.[32]

Surgical Therapy

Surgery may be indicated if patients are unable or unwilling to change their occupation or avoid participating high-risk sports and if they have recurrent dislocations or subluxations.

The question of the timing of surgery remains unclear. Several studies advocated arthroscopic or open stabilization procedures after the initial dislocation in lieu of the traditional method of surgical intervention after a trial of nonoperative treatment in patients with a history of multiple dislocations or subluxations.[33] In military recruits and in young athletes aged 17-27 years, studies showed far superior results with surgery after the initial dislocation in these patients, as opposed to the results after a trial of nonoperative treatment.[34, 35, 36, 37]

In a prospective trial, the repeat dislocation rate was 4% after arthroscopic stabilization of acute dislocations and 94.5% after nonoperative treatment.[38] In another study, patients were randomly assigned to immobilization and early surgical intervention. In these patients, the repeat dislocation rate was 15.9% at 2 years, and the recurrence rate was 47% in patients treated nonoperatively. Studies by Arciero et al,[39] Hintermann et al,[40] and Patel et al[35] should also be reviewed.

Historically, open stabilization procedures have had a rate of repeat dislocation rate slightly lower than that of arthroscopic procedures, but the discrepancy is significantly less today, as technical skills and anchoring devices have improved. In a study in Sweden, the arthroscopic failure rate was 15%, compared with an open stabilization failure rate of 10%.[41] External rotation was better maintained in the arthroscopic group (90°) than in the group that underwent open procedures (80°).

Another study of arthroscopic and open reconstruction revealed failure rates of 33% and 8%, respectively.[31] However, many authors believe that their arthroscopic results are the same as, if not better than, their results with open procedures for both athletes in contact sports and athletes in noncontact sports. The trend is toward minimally invasive surgery, and the results of arthroscopic instability repairs will continue to improve. A key element in a successful instability procedure is addressing any capsular laxity, whether by means of an open capsular shift, an arthroscopic capsular plication, thermal capsulorrhaphy, or rotator interval closure.

Various studies have suggested that the Instability Severity Index (ISI) score is an useful means of assessing the recurrence rate of dislocation after arthroscopic surgery in patients with shoulder instability. A study by Loppini et al found that arthroscopic stabilization was associated with a significantly lower risk of recurrence of glenohumeral instability in patients with an ISI score of 3 or lower than in those with an ISI score higher than 3.[42]  A study by Chan et al, however, found that the composite ISI score and its individual risk factors did not predict subsequent surgical failure after primary arthroscopic Bankart repair in an active military population.[43]

A study by Owens et al reviewed data from the American Board of Orthopaedic Surgery (ABOS) and noted that the use of open repair has declined, with a trend toward arthroscopic Bankart repair.[44] The study found that the most commonly reported complications were nerve palsy/injury and dislocation. The rate of nerve injury was 2.2% in the open group, compared with 0.3% in the arthroscopic group; the dislocation rate was 1.2% with open stabilization, compared with 0.4% arthroscopically.

The sequence for one technique is illustrated in the images below.

The rotator cuff interval is closed with a nonabso The rotator cuff interval is closed with a nonabsorbable suture. The T-capsulotomy incision is planned with dotted lines.
Superomedial (SM) and inferomedial (IM) flaps crea Superomedial (SM) and inferomedial (IM) flaps created by T-capsulotomy incision. First, the IM flap will be advanced superiorly and laterally, and then the SM flap will be advanced inferiorly over the top of the IM flap.
The finished repair with the superomedial (SM) fla The finished repair with the superomedial (SM) flap advanced inferiorly, overlapping the previous inferomedial (IM) flap advancement. Note how the axillary pouch has been eliminated.

Complications

Shoulder dislocations result in various associated arthroscopic findings and various vascular and neurologic complications.[45] One must be astute when examining patients for neurovascular compromise, both before and after reduction attempts.

Most patients with a first-time dislocation also have a Bankart lesion (ie, an avulsion of the anterior capsulolabral complex from the glenoid rim with disruption of the medial scapular periosteum).[46]  Variations of this injury include a bony Bankart lesion, in which the labrum remains intact but a fracture occurs through the anterior glenoid rim.

A Perthes lesion is similar to a Bankart lesion, except the medial scapular periosteum remains intact; thus, the labrum may appear normal on MRI and arthroscopy unless the arm is abducted and externally rotated away from the neutral position.

An anterior labroligamentous periosteal sleeve avulsion (ALPSA) differs from the Bankart lesion in that the anterior labrum is medially displaced. It heals in an abnormal position, leading to an incompetent anterior inferior glenohumeral ligament.

Hill-Sachs lesions commonly occur and are compression fractures that result from impaction of the posterolateral humeral head against the anterior/inferior glenoid rim, which can occasionally result in a loose body.[47]

One study examined whether failures of arthroscopic Bankart repairs related to Hill-Sachs lesions can be treated by “remplissage” (filling in) of the defect with rotator cuff tendon. The data noted no significant statistical difference in ROM between patients treated with arthroscopic Bankart repair alone and those treated with Bankart and remplissage. An identical rate of recurrence was found in both groups, and one third of patients experienced posterosuperior pain.[48]

Rotator cuff tears are rare in young individuals but common in older patients. Approximately 30% of patients older than 40 years have a cuff tear, as do about 80% of patients older than 60 years. Greater tuberosity fractures also occur with dislocations in older patients, and these have been associated with a lower incidence of recurrent dislocations. Older patients are less likely to have a Bankart lesion and more likely to have a cuff tear, a greater tuberosity fracture, or an avulsion of the capsule and subscapularis from the lesser tuberosity; younger patients more commonly have labral tears. Coracoid fractures may also occur as a result of an anterior dislocation or a difficult reduction attempt.

Vascular injuries are rare, but they may occur with anterior or inferior dislocations, especially in older patients with atherosclerosis of the axillary artery. The humeral head displaces the artery anteriorly over the head, and the pectoralis muscle acts as a fulcrum against the artery, leading to rupture. Arteriography should be performed if a vascular injury is possible. Because of the proximity of the two structures, arteriography should be strongly considered whenever a brachial plexus injury is observed.

Most commonly, patients present with delayed vascular compromise secondary to an intimal injury and resultant occlusion. Acute obstruction or rupture occurs in about 3.3% of cases of luxatio erecta.[13] Pseudoaneurysm may also occur, especially after recurrent dislocations. Subclavian vein thrombosis may result from a venous injury and present with unilateral swelling and pain.

Neurologic injuries are more common than vascular injuries, particularly axillary neurapraxias, which are found in about 8-10% of patients with anterior dislocations. Patients have weakness in abduction and external rotation, as well as numbness over the lateral aspect of the upper arm. Among possible neurologic complications, these lesions have the poorest prognosis. Radial nerve injuries must also be considered in cases of axillary nerve damage because both arise from the posterior cord. These injuries may result in weak thumb, wrist, and elbow extension, as well as numbness on the dorsal aspect of the hand.

Long thoracic nerve palsies may also result from traction on the nerve, leading to scapular winging due to paralysis of the serratus anterior. Suprascapular nerve palsies cause weakness in abduction and external rotation. Dorsal scapular nerve injuries cause weakness in abduction. Musculocutaneous injuries lead to weak elbow flexion and supination, as well as lateral forearm numbness.

Arthroscopic findings after shoulder dislocation include the following:

  • Bankart lesions in 80-89% of patients
  • Anterior capsular insufficiency in 74% of patients
  • Hill-Sachs lesions in 67% of patients
  • Inferior glenoid labral tears in 51% of patients
  • Glenohumeral ligament insufficiency in 50% of patients
  • Partial or complete rotator cuff tears in 13% of patients
  • Dysplastic glenoid in 13% of patients
  • Biceps tendon lesions in 12% of patients
  • Brachial plexus injuries in 11% of patients
  • Posterior glenoid labral tear in 11% of patients
  • Axillary nerve injuries in 8-10% of patients
  • SLAP (superior labral tear from anterior to posterior) lesions in 8% of patients
  • Partial subscapularis tear in 8% of patients
  • Loose bodies in 5% of patients

Williams et al, in a systematic review of 56 studies (N = 4336; 4362 procedures) aimed at quantifying the incidence of complications associated with all types of surgery for anterior glenohumeral joint dislocation,[49]  reported the following complication rates:

  • Arthroscopic soft-tissue repair (n = 2805), 1.6%
  • Arthroscopic repair combined with arthroscopic remplissage (n = 219), 0.5% 
  • Open soft-tissue repair (n = 219), 6.2%
  • Open labral repair with remplissage (n = 79), 2.3%  
  • Open bone-block procedure (n = 573), 7.2% 
  • Arthroscopic bone-block procedure (n = 163), 13.6%