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Disease/ Disorder

Definition

There are various types of traumatic shoulder injuries, including fractures, dislocation, and soft tissue injuries. Fractures commonly involve the clavicle, proximal humerus, and/or the scapula. A shoulder dislocation/separation can involve any of three different joints, with the glenohumeral joint being the most commonly involved. Soft tissue injuries are discussed in other templates and will not be discussed in this publication.1

Etiology

Anterior dislocations are most often due to a sudden loading of the arm while in abduction, external rotation, and extension. Direct injury mechanisms such as a direct blow to the posterior aspect of the shoulder are less frequent. Posterior dislocations are less common and are due to either a forceful and sudden contraction of the shoulder muscles (e.g., seizure or electric shock) or falling on an outstretched arm that is flexed, adducted, and internally rotated.2

Acromioclavicular (AC) joint injuries, also known as shoulder separations, are most commonly from falls directly onto the shoulder, typically onto the lateral or superior aspect of the shoulder with the shoulder adducted. Shoulder fractures commonly involve the clavicle, proximal humerus, and scapula. A direct blow to the area, collision, or a motor vehicle accident can also cause fractures of the clavicle or the proximal humerus. Scapular fractures are rare, but when they occur they are usually secondary to high-energy trauma.1

Epidemiology including risk factors and primary prevention

In the United States, the incidence of shoulder dislocations is 23.9/100,000-person years and approximately 85–98% of initial shoulder dislocations are anterior dislocations. Dislocated shoulders tend to occur more often in males than in females. 71.8% of shoulder dislocations are in males. 2 This gender difference is likely due to association with contact sports. In men, the peak age is 20-30 years and it is 61-80 years in women.3 The later peak in women is attributed to increased falls in an aging population.

The incidence of proximal humerus fractures increases with age, by about 15% per year, as does the number of complex fractures.4,5 Humeral fractures are common in the elderly population, with a population-adjusted incidence of 101 per 100,000 person years in those over 65 years old.6 This is especially true in older women who account for the majority of proximal humerus fractures.7

Clavicle fractures account for approximately 2.6% to 10% of all fractures across all sports, with a worldwide incidence of 17.4 to 91 per 100,000 person years.8 The peak incidence occurs in bimodal distribution with ages younger than 18 years old and older than 70 years old. Over one-third of clavicle fractures in males occur between the ages of 13 and 20 years, while 20% of clavicle fractures in women occur in the same age group.9 Scapular fractures on the other hand are uncommon, representing less than 1% of all fractures.1

The incidence of AC joint separation is between 9-12% of shoulder girdle injuries, with Type I or II making up the majority of that percentage. The majority are due to contact sports and occur in young males between 20 to 30 years of age.10

Patho-anatomy/physiology

There are three primary types of shoulder dislocations: anterior, posterior, and inferior. Anterior dislocation accounts for most of the cases, followed by posterior dislocations. An inferior dislocation occurs when the arm is forced into hyperabduction, causing the abutment of the humerus against the acromion with subsequent separation of the humeral head from the glenoid.3

Proximal humeral fractures (PHF) are classified using the Neer system, which is based on fracture location relative to the greater tuberosity, lesser tuberosity, head, and shaft. PHF are considered non-displaced if no segment is displaced more than 1 cm or angulated more than 45 degrees, while displaced fractures are classified according to the number of displaced fragments.6

The anatomic sites of clavicle fractures are typically described using the Allman classification, which divides the clavicle into thirds (proximal, midshaft, and distal), with midshaft fractures representing approximately 75 to 80% of all clavicle fractures. Lastly, 50% of scapular fractures occur in the body or spine of the scapula.3

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

In patients with a first-time shoulder dislocation, the outcome most frequently measured over time is recurrent instability. Younger age with first time dislocation has an increased risk of developing recurrent dislocations with 50% of patients between 15 to 30 years old developing recurrent instability.11 Patients with a single shoulder dislocation have an estimated 18% risk of developing shoulder arthropathy, while those with recurrent dislocations have a 40% chance. Persistent apprehension, inability to return to sports, glenoid bone loss and post-traumatic arthritis are other outcomes that may be present in those with history of shoulder dislocation.12,13

The overall prognosis for PHF’s depends on numerous factors: fracture pattern, patient age, associated comorbidities, and willingness of the patient to undergo lengthy rehabilitation.6 Most clavicle fractures treated non-operatively heal, although with variable amounts of cosmetic deformity.14 In scapular fractures, if no significant associated injury exists, complete or near complete recovery is expected.3

Specific secondary or associated conditions and complications

In patients less than 24 years old with anterior dislocation, anterior inferior labrum disruption is described in the literature to occur in 87-97% of patients, posterolateral humeral cortical compression fracture (Hill-Sachs lesion) in 67-89% of patients, and Superior Labrum Anterior and Posterior (SLAP) tears in 10% of patients. In patients older than 30 years old, there is a 53% incidence of rotator cuff tears associated with anterior shoulder dislocations. Bankart and Hill-Sachs lesions occurs in 73-100% of patients, and humeral avulsion of the glenoid ligament occurs in up to 9.3% of patients.15 Other complications include axillary nerve and artery injury and brachial plexus injury.13 The “terrible triad” has been described in the literature and includes a shoulder dislocation with a fracture, rotator cuff tear, and brachial plexus injury.2,16

Complications associated with PHF’s include neurovascular injury, avascular necrosis of the humeral head, and adhesive capsulitis. In displaced or comminuted clavicle fractures complications include subclavian vessels injury, hemopneumothorax, brachial plexopathy, nonunion, malunion, posttraumatic arthritis, and recurrent fracture.3

Essentials of Assessment

History

Essential components of the history in a patient with a shoulder injury include time of onset, location, mechanism of injury, associated symptoms (e.g., neurovascular), modifying conditions, history of prior shoulder injuries, and previous interventions. Pain, swelling, loss of function, snapping/cracking sensation, instability (e.g., shoulder feeling loose), and possible deformity over the affected area may be described.

Physical examination

The examination should begin with inspection of the affected arm in the resting position (e.g., extremity held in adduction) looking for evidence of atrophy, bruising, abrasion asymmetry, muscle contraction, or deformity that may suggest direct trauma. Palpation of the affected and surroundings areas is performed assessing for tenderness, crepitance, or bony abnormalities. An assessment of active and passive range of motion (ROM), muscle tone, strength, and neurovascular status is then performed. Cervical spine examination may be needed.

Special testing should include evaluation for rotator cuff strength (e.g., Empty Can, External Rotation, Belly/Lift-off), impingement testing (e.g., Hawkin’s sign and Neer’s test), long head of biceps tendon testing (e.g., Yergason’s and Speed’s Tests), laxity/instability testing (e.g., load and shift, apprehension/relocation, and sulcus sign), and labral testing (e.g., O’Brien’s and Biceps Loading). It is important to note that passive ROM may be limited due to pain and in an acute setting the shoulder should not be passively moved beyond 90 degrees in any direction due to risk of re-dislocation.

Functional assessment

Shoulder functional assessment can be evaluated through active and passive ROM and muscle length, strength, and joint mobility assessment. The American Shoulder and Elbow Surgeons have adopted a standardized form that contains visual analog scales for pain and instability and activities of daily living questionnaire to measure shoulder function and outcome.17

Laboratory studies

Laboratory studies are not considered routine in subluxation or dislocation events. PHF are often associated with diabetes, rheumatological conditions, or osteoporosis and calcium deficiency. Recommended initial laboratory studies include 25-hydroxycalciferol, calcium, parathyroid hormone, thyroid stimulating hormone, alkaline phosphatase, phosphorus, and creatinine. Bone mineral density may be assessed by dual-energy x-ray absorptiometry (DEXA).

Imaging

Radiographs are the preferred initial test to detect dislocations and fractures. Suggested views include an anterior-posterior (A/P), axillary, true A/P in scapular plane (Grashey view), A/P in internal rotation, and Stryker view. Depending on the location of the fracture (e.g., scapula or clavicle) and findings in the initial radiographs, specific views may be warranted. The need for advanced imaging (e.g., CT or MRI) is mainly dependent in part on initial radiographic findings and in those who are surgical candidates.3

Supplemental assessment tools

Multiple assessment tools are utilized as a standard method to determine shoulder functionality in patients with shoulder injuries. Outcome measures include evaluation of pain, functionality, ROM, symptomatology, level of independence, and treatment satisfaction. Multiple questionnaires are currently available: Quick DASH scores, Constant Scores, Visual Analog Scale scores, Simple Shoulder Test, Short Form-36, and the Oxford Shoulder Scores.18 Results from these allow the clinician to evaluate effectiveness of treatment and the degree of limitation secondary to shoulder pathology.

Early predictions of outcomes

Younger age is a significant predictor for shoulder dislocation recurrence. A number of studies have found the recurrence rate to be as high as 90% over two years in patients less than 25 years old. 19-21 Associated risk factors include number of prior dislocations, activity level, male sex, and prior history of bony defects, capsular deformation, or ligamentous injuries/laxity. Conversely, recurrence is less than 10% in older populations, largely due to the predominance of concomitant rotator cuff injuries as opposed to bony or ligamentous injuries as with younger populations.Outcomes in shoulder fractures are dependent mostly on patient’s age, comorbidities, associated complications, and location and nature of the fracture.

Social role and social support system

Treatment outcomes involve the cooperation of the patient, the parents of young patients, and the athletic trainers and coaches in those involved in sports injuries. Sport psychologists can address coping with the natural process of the disease, the timing of recovery, and the treatment expectations.

Professional Issues

The return to premorbid activities, such as the return to play in athletes and return to work in professional individuals are important aspects in the management of shoulder injuries. There should be a multidisciplinary approach, with discussion of the natural process of the injury, treatment options, and patient’s goals in order to make an informed decision.

Rehabilitation Management and Treatments

Available or current treatment guidelines

Acute management of shoulder dislocation typically includes closed reduction. This should be completed as soon as possible as a delay greater than 24 hours increases the risk of recurrent instability. There are several techniques, but consensus states that the physician should perform the techniques in which he or she is most proficient. After reduction, the arm is placed in a sling and immobilized for at least 1 week. After this period early gentle ROM is recommended to minimize capsular contraction. Restrictions for the first 4-6 weeks include no abduction and external rotation at 90° or greater of abduction to prevent re-dislocation. Scapular strengthening will be introduced at the 6-week mark.22, 23

Management of fractures depends on patient’s age, activity level, location, and whether fracture is displaced, non-displaced, or comminuted. Non-operative management remains the most common approach for non-displaced and minimally displaced fractures. ROM pendulum and stretching exercises can be started as soon as pain allows, with gradual progression to active ROM and strengthening exercises over 4-6 weeks. For clavicle fractures, a sling, figure-of-eight splint, or a combination of both may be used; currently there is no consensus on the optimal duration of immobilization but ranges from 2 to 6 weeks.14, 18, 24

Displaced fractures causing neurovascular or hemodynamic instability, or those that have high rate of non-union or sequelae may require operative treatment. Post-operative rehabilitation after surgical management for a clavicle fracture generally includes sling immobilization for 2-4 weeks, with immediate ROM exercises as tolerated.10 Patients with PHF treated with Open Reduction and Internal Fixation (ORIF) are placed in a sling for 6 weeks and started in gentle ROM exercises 2 weeks postoperatively with gradual progression, adding strengthening exercise at 3 months postoperatively.16,14,18

Return to sport (RTS) in patients treated conservatively following a shoulder dislocation or fracture will be allowed once full ROM and strength have been regained. Typically, this is limited return at 3 months and full return at 4 months. RTS after a shoulder fracture, treated surgically, may take an average of 3-6 months, but readiness will be influenced by multiple factors (e.g., age, associated complications, nature and location of fracture, ROM, strength, and surgical technique).16,18

At different disease stages

The patient should be referred to an orthopaedic surgeon if the following conditions are diagnosed: glenoid osseous defect greater than 25%, displaced medial clavicle fractures, humeral head articular surface osseous defect greater than 25%, proximal humerus fracture requiring surgery, irreducible dislocation, failed trial of rehabilitation, continued pain and mechanical symptoms after conservative management, inability to tolerate shoulder restrictions, and inability to perform sport-specific drills without instability. While not absolute, orthopaedic referral should be considered in young patients with more than 2 shoulder dislocations during a season, overhead or throwing athletes, contact sport athletes, and injury near the end of a season.22,23

Coordination of care

Improved outcomes are obtained when patients are managed in a multidisciplinary manner. Communication between the patient, family members, coaches, orthopedic surgeon, physiatrist, physical and occupational therapist, nursing staff, case manager, and others is essential to obtain good outcomes.

Patient & family education

The patient, parents, coaches, and trainers should be fully involved in care. They should be educated about the findings, expectations, and recommendations. Patients should be educated on the various operative and non-operative treatment options, possible complications, and the recovery timeline for their injury.

Emerging/unique interventions

Reverse shoulder arthroplasty (RSA) has gained wide acceptance for treating PHF’s in the elderly. Excellent results have been observed and have demonstrated more reliable outcomes when compared to hemiarthroplasty, for which RSA is currently being favored in the elderly population.25

Recent studies suggest that conservative interventions for shoulder dislocations reveal unsatisfactory results, primarily in the young and athletic patients. Some advocate for orthopedic surgery referral after an initial dislocation to minimize risk of further glenoid bone loss. Early arthroscopic remplissage has demonstrated to be an effective technique with respect to recurrence rate, ROM, and shoulder function.26

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

When deciding the optimal treatment intervention in patients with a shoulder fracture or dislocation factors to take into consideration include patient’s age, activity level, dominant side, possible associated complications, and location of the fracture. Whether the injury is managed surgically or non-surgically, early motion is crucial in obtaining adequate functional outcomes.

Cutting Edge/ Emerging and Unique Concepts and Practice

Ultrasound has the potential to save time, radiation exposure, healthcare costs, and possible need for re-sedation in patients that present to the emergency room with a shoulder dislocation. A systematic review compared the diagnostic accuracy of ultrasound compared with plain radiography and observed that ultrasound may be considered as an alternative diagnostic method for the detection of shoulder dislocation and reduction.27 However, if there is clinical suspicion for concomitant fractures, clinicians should not rely solely on ultrasound. In a prospective observational study completed at two academic emergency departments, point of care ultrasound missed 48% of concomitant fractures. The results of this study are limited by sonographers being blinded to physical exam and history findings.28

As described above, non-operative management remains the most common approach for non-displaced fractures, but recent studies have demonstrated that in the elderly population RSA is a reliable treatment option, as better outcomes have been proven when compared to hemiarthroplasty.25

Gaps in the Evidence-Based Knowledge

There is still no consensus in the literature about the management of patients presenting with first-time traumatic anterior dislocation of the shoulder. The traditional standard approach of immobilization as a definitive treatment after the reduction is being challenged due to the high rate of recurrence. A Cochrane review found insufficient evidence to inform choice of immobilization and recommended further high-quality trials on the subject.29 In a systematic review, there was moderate quality evidence suggesting labral repair reduced risk of recurrent shoulder dislocation.30  Although the data for labral repair showed a reduction in recurrent shoulder dislocation, there is a high number needed to treat (2.5-5.6), with previous studies suggesting that delaying surgery after first time traumatic shoulder dislocation did not cause a less favorable prognosis of instability. With nonsurgical management, 47% of patients did not experience shoulder redislocation.30

One of the largest evidence gaps is the treatment options for chronic post-traumatic shoulder instability, especially in regards to surgical vs nonsurgical treatment. Open labral repair and arthroscopic repair are two potential treatments, however there are limited studies showing long term impact on quality of life post-surgery.30

Although the majority of fractures are treated non-operatively, the most appropriate form of management (surgical vs. conservative) is currently less clear when it comes to elderly patients. In addition, few guidelines are currently available as to staging physical therapy interventions to maximize ROM, strength, and optimize activities of daily living in these patients.24

References

  1. Pavlov, H and Freiberger, H. Fractures and Dislocations About the Shoulder. Seminars in Roentgenology. 1978.12(2):85-96
  2. Zacchilli, M. A., & Owens, B. D. (2010). Epidemiology of shoulder dislocations presenting to emergency departments in the United States. The Journal of Bone and Joint Surgery-American Volume, 92(3), 542–549..
  3. Sheenan, S et al. Traumatic Shoulder Injuries: A Force Mechanism Analysis-Glenohumeral Dislocation and Instability. AJR. 2013; 201:378–393.
  4. Roux, A. Epidemiology of proximal humerus fractures managed in a trauma center. Orthopedics & Traumatology: Surgery & Research.2012;98: 715-719.
  5. Launonen AP, Lepola V, Saranko A, Flinkkilä T, Laitinen M, Mattila VM. Epidemiology of proximal humerus fractures. Arch Osteoporos. 2015;10:209.
  6. Lee SH, Dargent-Molina P, Breart G. Risk Factors for Fractures of the Proximal Humerus: Results From the EPIDOS Prospective Study. Journal of Bone and Mineral Research. 2002(17);817-25.
  7. Launonen AP, Lepola V, Saranko A, Flinkkilä T, Laitinen M, Mattila VM. Epidemiology of proximal humerus fractures. Arch Osteoporos. 2015;10:209
  8. Oberle L, Pierpoint L, Spittler J, Khodaee M. Epidemiology of Clavicle Fractures Sustained at a Colorado Ski Resort. Orthop J Sports Med. 2021 May 11;9(5):23259671211006722.
  9. Hatch, R et al. (2017) Clavicle fracture. UpToDate. Retrieved from https://www.uptodate.com/contents/clavicle-fractures
  10. Hibberd EE, Kerr ZY, Roos KG, Djoko A, Dompier TP. Epidemiology of Acromioclavicular Joint Sprains in 25 National Collegiate Athletic Association Sports: 2009-2010 to 2014-2015 Academic Years. Am J Sports Med. 2016 Oct;44(10):2667-2674.
  11. Olds M, Ellis R, Donaldson K, Parmar P, Kersten P. Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis. Br J Sports Med. 2015 Jul;49(14):913-22.
  12. Griffith JF, Antonio GE, Yung PS, Wong EM, Yu AB, Ahuja AT, Chan KM. Prevalence, pattern, and spectrum of glenoid bone loss in anterior shoulder dislocation: CT analysis of 218 patients. AJR Am J Roentgenol. 2008 May;190(5):1247-54..
  13. Boone J, Arciero R. First-time anterior shoulder dislocations: has the standard changed? Br J Sports Med. 2010; 44: 355-360.
  14. Paladini, P. Treatment of Clavicle Fractures. Transl Med UniSa.2012;2:47–58.Singleton, E. Rehabilitation After Proximal Humeral Fractures. Techniques in Shoulder & Elbow Surgery.2014:15(1):46-40.
  15. Petterson SC, Agyapong G, Brite JE, Shanmugam J, Briggs KK, Plancher KD. An algorithm for successfully managing anterior shoulder instability. JAAPA. 2022 Apr 1;35(4):17-28. doi: 10.1097/01.JAA.0000823168.14527.15. PMID: 35276714
  16. Groh GI, Rockwood CA. The terrible triad: Anterior dislocation of the shoulder associated with rupture of the rotator cuff and injury to the brachial plexus.J Shoulder Elbow Surg.1995;4(1):51-53.
  17. Schmidt, Stefanie, et al. Evaluation of Shoulder-Specific Patient-Reported Outcome Measures: a Systematic and Standardized Comparison of Available Evidence. Journal of Shoulder and Elbow Surgery, vol. 23, no. 3, 2014, pp. 434–444.
  18. Robertson, G and Wood, A. Return to sport following clavicle fractures: a systematic review British Medical Bulletin.2016;119(1):111–128.
  19. Pevny T, Hunter RE, Freeman JR. Primary traumatic anterior shoulder dislocation in patients 40 years of age and older.Arthroscop. 1998;14(3):289-294.
  20. McLaughlin HL, MacLellan DI. Recurrent anterior dislocation of the shoulder: II, a comparative study. J Trauma. 1967;7(2):191-201.
  21. Zacchilli MA, Owens BD. Epidemiology of shoulder dislocations presenting to emergency departments in the United States.J Bone Joint Surg Am. 2010;92:542-549.
  22. Burns TC, Owens BD. Management of shoulder instability in in-season athletes.Phys Sportsmed.2010;38(3):55-60.
  23. Owens BD, Dickens JF, Kilcoyne KG, Rue JP. Management of mid-season traumatic anterior shoulder instability in athletes.J Am Acad Orthop Surg.2012;20(8):518-526.
  24. Chuinard, C.Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture. Techniques in Shoulder & Elbow Surgery.2016;17(3):122-130.
  25. Haviv, B., Mayo,L.,and Biggs, D. Outcomes of arthroscopic “Remplissage”: capsulotenodesis of the engaging large Hill-Sachs lesion. Journal of Orthopaedic Surgery and Research.2011;6:29.
  26. Gottlieb, M. and Russell, F. Diagnostic Accuracy of Ultrasound for Identifying Shoulder Dislocations and Reductions: A Systematic Review of the Literature. Western Journal of Emergency Medicine.2017;18(5):937-942.
  27. Hunter, M., Mackenzie, M. & Packer, N. Does musculoskeletal ultrasound play a role in diagnosing and managing shoulder dislocations? Can J Emerg Med 23, 463–465 (2021).
  28. Handoll HH, Almaiyah MA, Rangan A. Surgical versus non-surgical treatment for acute anterior shoulder dislocation.Cochrane Database Syst Rev.2004;(1):CD004325.
  29. Kavaja L, Lähdeoja T, Malmivaara A, Paavola M. Treatment after traumatic shoulder dislocation: a systematic review with a network meta-analysis. Br J Sports Med. 2018 Dec;52(23):1498-1506.

Original Version of the Topic

Jason L. Zaremski, MD, Daniel C. Herman, MD, PhD, Kevin Vincent, MD. Shoulder fractures, separation-dislocation, and other soft tissue injuries. 9/20/2014.

Previous Revision(s) of the Topic

William Micheo, MD, Brenda Castillo, MD, Jose R. Vives, MD, Javier González, MD. Shoulder fractures, separation-dislocation, and other soft tissue injuries. 9/6/2018.

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Daniela Mehech, MD
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Nirmal Maxwell, DO
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Claire Cooper, DO
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