Chapter 1 – Shoulder




Chapter 1 Shoulder



Christopher Guyer



Background/Epidemiology




  • Shoulder pain is a common chief complaint in the emergency department (ED). Prevalence estimates of shoulder pain vary widely across different populations.1



  • Limited data on the epidemiology of upper extremity injuries presenting to the ED currently exist.



  • Recent data show the incidence of shoulder injury is 190 injuries per 100,000 persons per year.2



  • Traumatic shoulder injuries account for 17 percent of upper extremity injuries presenting to EDs. The most common type of injuries seen are fractures (29 percent), strains/sprains (16 percent), and dislocations (5 percent).2



  • Shoulder injuries are sustained as a result of many scenarios such as participation in sports, accidental trauma sustained in the home and at work, overuse injuries, and motor vehicle accidents.



  • Shoulder injuries can be categorized as acute and nonacute.




    • Acute shoulder injuries include traumatic instability, acromioclavicular (AC) and sternoclavicular (SC) joint injury, proximal humerus fractures, scapular fractures, and clavicle fractures.



    • Anterior and anteroinferior instability account for more than 90 percent of shoulder dislocations.



    • Nonacute shoulder injuries include impingement, rotator cuff tendinopathy and tear, biceps tendinopathy and tear, multidirectional instability, and labrum tears.



Anatomical Considerations/Pathophysiology




  • The shoulder is the most mobile joint in the body.



  • It is comprised of three bones and four articulations (Figure 1.1).




    • Three bones:




      • Clavicle, scapula, and humerus.



      • The acromion is an extension from the spine of the scapula and forms a roof over the shoulder joint.




        • A type I acromion has a flat undersurface.



        • A type II acromion has a downward curve and decreased angle of inclination.



        • A type III acromion has a hooked appearance with further decreased angle of inclination.



      • The proximal humerus has four main parts:




        • Humeral head



        • Greater tuberosity



        • Lesser tuberosity



        • Metaphyseal portion of the shaft



    • Four articulations:




      • SC, AC, glenohumeral, and scapulothoracic.



      • The SC joint is the only true articulation between the upper extremity and the axial skeleton.



      • The scapulothoracic articulation is the interface between the scapula and the thorax and does not represent a true joint.



  • The glenoid labrum is composed of dense fibrocartilage and increases the surface area of the glenohumeral joint to deepen the socket and provide stability for the joint.



  • The muscles of the shoulder attach to the scapula, clavicle, and humerus (Figures 1.2 and 1.3).



  • The deltoid muscle provides primary motor power at the glenohumeral joint.




    • It functions in elevation, forward flexion, abduction, and extension of the shoulder.



    • It is innervated by the axillary nerve.



  • The rotator cuff comprises four muscles and provides dynamic stability to the glenohumeral joint:




    • Supraspinatus



    • Infraspinatus



    • Teres Minor



    • Subscapularis



  • The supraspinatus functions in shoulder elevation and is innervated by the suprascapular nerve.



  • The infraspinatus functions in external rotation of the shoulder and is innervated by the suprascapular nerve.



  • The teres minor functions in external rotation of the shoulder and is innervated by the axillary nerve.



  • The subscapularis functions in internal rotation of the shoulder and is innervated by the subscapular nerve.



  • Other muscles involved with motion at the shoulder include the following:




    • Pectoralis major



    • Latissimus dorsi



    • Biceps brachii



    • Trapezius



    • Rhomboids



    • Levator scapulae



    • Serratus anterior





Figure 1.1. Bony anatomy of the shoulder.





Figure 1.2. Anterior shoulder muscular anatomy.





Figure 1.3. Posterior shoulder muscular anatomy.



Focused History and Physical Exam




  • Assessment of shoulder complaints requires taking a focused history.



  • Important historical features regarding the onset of pain or dysfunction include eliciting a traumatic mechanism of injury, degenerative or inflammatory conditions, or causative factors from other regions in the body.




    • In adolescents and young adults traumatic injury and poor postural habits are common causes of shoulder complaints.



    • In older patients shoulder complaints can be attributed to overuse in sports or occupational activities, and to wear of articular and periarticular structures.



  • The history should include the site and type of pain, duration, and time of occurrence.




    • Referred pain occurs in the subacromial bursa.



    • Pain from a rotator cuff tear is commonly referred to the proximal upper arm or felt diffusely in the deltoid.



    • AC symptoms are usually located directly over the joint.



    • Night pain is common in rotator cuff injury and in advanced impingement syndromes like calcific tendinitis.



  • Some patients cannot precisely describe the location of pain and radiation into the arm, trunk, and head can occur.




    • It’s important to distinguish shoulder disorders from neurovascular disorders such as distal compression neuropathies, thoracic outlet syndrome, cervical rib syndrome, cervical spine disorders or injury, and other disorders such as splenic rupture and cardiopulmonary disease.



  • Additional historical features include:




    • Right or left handedness



    • Occupation, hobby, or sports participation



    • Chronic or recurrent symptoms



    • Previous diagnosis



    • Past surgical interventions



    • Treatments the patient has tried, including the use of oral and topical medications, heat and cold therapy, and a sling or brace



    • Restrictions with range of motion



    • Difficulty with activities of daily living




      • Males will commonly note difficulty reaching a wallet in their back pants pocket, putting on a shirt, or fastening a seatbelt.



      • Women will commonly note difficulty hooking a bra or doing their hair.3



  • Physical examination of the shoulder should be systematic and include inspection, palpation, range of motion, special maneuvers, and neurovascular evaluation.



  • Inspection begins with looking for joint symmetry, alignment, bony deformities, swelling, scars, ecchymosis, atrophy, and hypertrophy.




    • Note any abnormalities on observation of the shoulder, shoulder girdle, and related musculature anteriorly and posteriorly.



    • Identify any swelling, deformity, muscle atrophy, hypertrophy, fasciculations, or abnormal positioning.



    • Observe for swelling of the joint capsule anteriorly or a bulge in the subacromial bursa.



    • Examine the entire upper extremity for color change, skin alteration, and abnormal bony contours.



  • Palpate bony structures of the shoulder first, then palpate any areas of pain.




    • While palpating, watch for any areas of tenderness or swelling.



    • First palpate the SC joint medially and follow the clavicle laterally with your fingers.



    • Posteriorly palpate the spine of the scapula and follow it laterally and upward until you reach the anterior tip of the acromion.



    • With your index finger on top of the acromion, posterior to the tip, press your thumb medially and find the slightly elevated ridge that marks the distal edge of the clavicle at the AC joint.



    • Medially and a short step down, palpate the coracoid process of the scapula.



    • On the lateral aspect of the humerus, palpate the greater tubercle, where the rotator cuff muscles insert.



    • Move your fingers just medial to the greater tubercle to palpate the biceps tendon within the intertubercular groove.



    • To palpate the subacromial bursa, subdeltoid bursa, and the rotator cuff muscles, extend the humerus to bring these structures anterior to the acromion.




      • Supraspinatus lies directly under the acromion.



      • Infraspinatus sits posterior to the supraspinatus.



      • Teres minor is found posterior and inferior to the supraspinatus.



      • Subscapularis inserts anteriorly and is not palpable.



      • Looking down on the shoulder from above, assess for swelling in the fibrous articular capsule and synovial membrane.



      • Palpate the capsule and synovial membrane under the anterior and posterior acromion.



  • Range of motion should be assessed starting with active range of motion, then with passive range of motion if any active restrictions are noted.




    • All range of motion assumes a neutral-zero method, where 0° is represented by the patient’s arm hanging down at his or her side.



    • The shoulder girdle is capable of moving in six directions: flexion, extension, abduction, adduction, and internal and external rotation.



    • Stand in front of the patient and observe for smooth movement.



    • Note muscle strength for each direction.



    • For flexion or forward elevation (Figure 1.4), ask the patient to raise the arms in front and overhead.




      • Normal range of motion is from 0° to 160–180°.



    • For extension (Figure 1.4), ask the patient to raise the arms behind the body.




      • Normal range of motion is 0–60°.



    • To test abduction (Figure 1.4), ask the patient to raise the arms above the head.




      • Normal range of motion is 0–180°.



      • Glenohumeral range of motion is 0–90°.



      • Scapulothoracic motion is 90–150° of abduction.



      • Both glenohumeral and scapulothoracic motion account for the last 30° of motion.



      • Painful arc is present when the patient experiences pain between 60° and 120° of active abduction.



    • For adduction, ask the patient to cross the arm in front of the body.




      • Normally, a patient should be able to touch the opposite shoulder.



    • To test internal rotation, ask the patient to place one hand behind the back and touch the shoulder blade.




      • Identify the highest spinous process the patient can touch.



      • Normally patients will be able to reach T7–T10. T9 is near the lower border of the scapula and serves as a good landmark.



      • Often patients will be able to reach higher with the nondominant hand.



    • For external rotation, ask the patient to raise the arm to shoulder level, bend the elbow, and raise the forearm to the ceiling.




      • Normal range of motion is up to 90°.



  • There are more than twenty special maneuvers for testing shoulder function but not all are well studied. Commonly performed maneuvers are described later.




    • The crossover test (Figure 1.5) is used to assess for injury to the AC joint.




      • While palpating the AC joint, adduct the patient’s arm across the chest.



      • A positive test will elicit pain at the AC joint.



    • Apley scratch test (Figures 1.6 A and B) assesses overall shoulder rotation.




      • Ask the patient to reach behind the head and touch the top of the scapula (Figure 1.6A). This tests abduction and external rotation.



      • Next, ask the patient to reach behind the back and touch the bottom of the scapula (Figure 1.6B). This tests adduction and internal rotation.



      • Difficulty with either of these motions is suggestive of a rotator cuff disorder, adhesive capsulitis, or glenohumeral osteoarthritis.



    • Neer’s impingement sign (Figure 1.7) evaluates for dynamic subacromial impingement, including constriction, inflammation, or injury to the rotator cuff.




      • Stabilize the scapula with one hand and with the other hand internally rotate the shoulder and then move the patient’s arm into forward flexion.



      • A positive test will elicit pain as the shoulder is placed into forward flexion as the greater tuberosity of the humerus rotates below the acromion.



    • Hawkins–Kennedy impingement sign (Figure 1.8) is similar to Neer’s impingement sign and also evaluates for subacromial impingement.




      • Flex the patient’s shoulder and elbow to 90° with the palm facing down. Place one hand on the patient’s forearm and another on the arm and rotate the arm internally.



      • A positive test will elicit pain as the greater tuberosity is compressed against the coracoacromial ligament.



    • The empty can test (Figure 1.9) evaluates supraspinatus strength.




      • Elevate the arms to 90° in the scapular plane and internally rotate them at the shoulder so the thumbs are facing down. Ask the patient to resist as you press down on the arms.



      • A positive test is indicated by weakness.



    • The infraspinatus test (Figure 1.10) can help you evaluate for an infraspinatus disorder or tear.




      • With the arms at his or her side, ask the patient to bend the elbows to 90° and provide resistance as he or she presses the forearms outward.



      • A positive test is indicated by weakness.



    • The lift-off test (Figure 1.11) tests for subscapularis strength.




      • Ask the patient to place the arm in internal rotation with the dorsum of the hand on the back as you provide resistance.



      • A patient with a subscapularis tear will be unable to perform this maneuver.



    • The drop arm test (Figures 1.12A and B) is a good test in evaluating for a supraspinatus tear.




      • With the patient seated, passively abduct the arm to 120° (Figure 1.12A). Ask the patient to hold the arm in that position without support and then slowly bring it to his or her side (Figure 1.12B).



      • A positive test is indicated by failure to maintain an abducted position or a sudden drop of the arm as the patient brings the arms back down towards the side.



    • Speed’s test (Figure 1.13) is an indicator for biceps injury.




      • Ask the patient to elevate the arm in supination and 60° of forward flexion, and to maintain this position as you provide downward pressure on the arm.



      • Asymmetrical strength and pain in the region of the bicipital groove suggests a disorder of the long head of the biceps tendon.



    • Popeye sign (Figure 1.14) indicates a proximal long head of the biceps tendon rupture.




      • Ask the patient to abduct the arm to 90° and flex at the elbow (i.e., ask them to flex the muscles).



      • This sign is present when there is a large bump in the area of the biceps muscle belly.



      • It may only be obvious when compared to the contralateral side.



    • O’Brien’s active compression test (Figures 1.15a and b) is used to detect labral pathology.




      • Stand behind the patient and ask him or her to flex the affected arm to 90°, adduct 15° medially, and internally rotate the arm.



      • Place a downward force to the patient’s arm (Figure 1.15A).



      • Observe for pain that localizes to the AC joint or the shoulder joint.



      • Repeat the test with the arm maximally supinated (thumb up) (Figure 1.15B).



      • A positive test is indicated if pain is decreased with the second maneuver.




        • Superficial pain is associated with AC joint pathology, while deep pain or a click is associated with labral abnormalities.



  • A thorough neurovascular exam of the upper extremity is important in evaluation of patients with shoulder complaints.




    • Long thoracic nerve (C5–7) and spinal accessory nerve (CN XI) function is indicated by scapular winging.




      • While standing, have the patient forward flex the arm to 90° and push against a wall.



      • Medial scapular winging is indicative of serratus anterior weakness or long thoracic nerve dysfunction.



      • Lateral scapular winging is an indicator for trapezius weakness or spinal accessory nerve (CNXI) dysfunction.



    • The supraclavicular nerve (C4) provides sensory innervation to the skin over the superior shoulder and clavicular area.



    • The suprascapular nerve (C5–6) provides motor innervation to the supraspinatus and infraspinatus.




      • Its function is tested by resisted abduction and external rotation.



    • The axillary nerve (C5) functions in sensation of the shoulder joint and the skin covering the inferior area over the deltoid. It supplies motor innervation to the deltoid and teres minor muscles.




      • Motor function is tested by resisted abduction and external rotation.



    • The dorsal scapular nerve (C5) innervates the levator scapula and rhomboid muscles.




      • Motor function is tested by having the patient shrug the shoulders.



    • The lateral pectoral nerve (C5–7) innervates the pectoralis major.




      • Motor function is tested via resisted adduction.



    • The thoracodorsal nerve (C7–8) innervates the latissimus dorsi.




      • Motor function is tested with resisted shoulder adduction.



    • The upper and lower subscapular nerve (C5–6) innervates the teres minor and subscapularis.




      • Motor function is tested by resisted internal rotation.



    • The T2 segmental nerve provides sensory innervation to the axilla.



    • Vascular examination of the shoulder includes checking brachial, radial, and ulnar artery pulses, as well as capillary refill.



  • Neck examination should also be included when evaluating certain shoulder conditions, as radicular pain from C5–6 can mimic rotator cuff disorders.








Figure 1.4. Forward elevation, extension and abduction.





Figure 1.5. Crossover test for AC joint disorders.








Figure 1.6 A and B. Apley scratch test.





Figure 1.7. Neer’s impingement sign.





Figure 1.8. Hawkins–Kennedy impingement sign.





Figure 1.9. Empty can test.





Figure 1.10. Infraspinatus test.





Figure 1.11. Lift-off test.








Figure 1.12A and B. Drop arm test.





Figure 1.13. Speed’s test.





Figure 1.14. Popeye sign.








Figure 1.15 A and B. O’Brien’s active compression test.



Differential Diagnosis – Emergent and Common Diagnoses



Anterior Shoulder Dislocation



General Description



  • Glenohumeral dislocations make up more than half of all dislocations seen by emergency medicine physicians.



  • The glenohumeral joint can dislocate anteriorly, inferiorly, posteriorly, or superiorly.




Table 1.1. Emergent and Common Diagnoses in the Emergency Department





































Emergent Diagnoses Common Diagnoses
Shoulder dislocation Acromioclavicular separation, types I-III
Acromioclavicular separation, types IV-VI Proximal humerus fracture (elderly)
Posterior sternoclavicular dislocation Clavicle fracture
Certain proximal humerus fracures Rotator cuff impingement
Certain scapula fractures Subacromial bursitis
Certain clavicle fractures Rotator cuff tendinopathy
Septic arthritis Adhesive capsulitis
Any open fracture
Any injury associated with neurovascular compromise


Mechanism



  • In anterior or anteroinferior dislocations, the humeral head becomes dissociated from the glenoid fossa and can rest under the inferior rim of the glenoid, beneath the coracoid process and less commonly in an intrathoracic or subclavicular position (Figure 1.16).4




    • Anterior or anteroinferior shoulder dislocation is the most common type of traumatic instability, representing more than 90 percent of dislocations.



    • A Bankart lesion (Figure 1.17) and avulsion of the inferior glenohumeral ligament and labrum complex from the glenoid is the most common structural injury with shoulder dislocation occurring in greater than 90 percent of injuries.




      • A Bankart lesion occurs when the labrum detaches with or without a bony fragment.



    • Humeral avulsion of the glenohumeral ligament occurs less than 10 percent of the time.



    • A Hill–Sachs lesion (Figure 1.18) is an impression fracture on the posterior humeral head that results from abutment against the anterior glenoid rim as it dislocates.



    • A Hill–Sachs lesion, glenohumeral ligament avulsion and Bankart lesion can all contribute to instability.



    • Anterior and anteroinferior dislocation occurs after a force is applied to an abducted and externally rotated arm.



    • The risk of dislocation is higher in individuals with a prior dislocation and they may dislocate during general daily activities.



    • The younger a patient is at the initial injury, the higher the likelihood of recurrence: age less than 20, 80 percent or greater; age 20–40, 26–48 percent; age greater than 40, 0–10 percent.





Figure 1.16. Anterior-posterior shoulder x-ray demonstrating characteristic appearance of an anterior shoulder dislocation.







From Eiff, MP. Fracture Management for Primary Care. Elsevier 2012; 8:170, with permission.


Figure 1.17. Bankart lesion. A West Point view shows a fracture of the inferior aspect of the glenoid fossa (arrow).





Figure 1.18. Hill–Sachs lesion. Note the cortical depression of the posterosuperior humeral head caused by impaction with the glenoid rim (arrow).


From Eiff, MP. Fracture Management for Primary Care. Elsevier 2012; 8:170, with permission.


Presentation



  • Dislocations commonly happen following a traumatic injury.




    • This can occur in contact sports like football and hockey, or from activities like throwing or reaching for an overhead object where the shoulder is flexed greater than 90° with slight external rotation.



    • Other scenarios where dislocation may occur include falls, motor vehicle accidents, lightning strikes, and seizures.



  • Patients usually complain of severe shoulder pain.



  • Additionally, patients may note deformity and inability to use the arm.



Physical Exam



  • Typically, “squaring” of the shoulder is present with a loss of normal deltoid contour when compared to the uninjured shoulder.



  • Decreased active and passive range of motion will be present.



  • Patients will often refuse to move the shoulder.



  • The humeral head may be prominent anteriorly.



  • It is essential to document neurovascular findings pre and post reduction.




    • The axillary nerve is the most commonly injured nerve as the neurovascular bundle passes anterior to the glenohumeral joint.



Essential Diagnostics



  • X-rays are always indicated when a dislocation is suspected.




    • A shoulder trauma series should include an anterior-posterior (AP) view with the beam at right angle to the scapula (Figure 1.19), a “Y” view (true lateral) with the scapular wing seen “edge on,” (Figure 1.20) and an axillary view (Figure 1.21).



  • At a minimum, post-reduction radiographic views include an AP view and an axillary view.



  • It has been suggested that point-of-care ultrasound can also be an imaging modality used to diagnose glenohumeral dislocation and confirm reduction.5



  • Generally, CT scan and MRI are not indicated in the ED setting.





Figure 1.19. Normal anterior-posterior (AP) x-ray of the shoulder. Note the normal alignment of the humeral head and glenoid contours.





Figure 1.20. Normal scapular Y-view showing the humeral head overlying the glenoid positioned posterior to the coracoid. The Y-view gets its name from the Y shape of the scapula seen when looking at it laterally.





Figure 1.21. Axillary x-ray view of the shoulder shows normal alignment at the glenohumeral joint and the acromioclavicular joint.



ED Treatment



  • ED treatment includes prompt pain control and reduction of the dislocation.



  • Reduction is easiest before the onset of muscle spasm and pain; however, this is not common in the ED setting.



  • Recurrent dislocations are often more easily reduced.



  • Procedural sedation can be utilized to allow for reduction maneuvers.



  • Recent systematic review has suggested that reduction can be obtained using intra-articular lidocaine injection as an alternative to procedural sedation.




    • This study demonstrated decreased emergency department time and complications for intra-articular lidocaine compared with IV sedation.



    • This method may be considered as the first option for reducing shoulder dislocations.6



  • Ultrasound-guided brachial plexus and interscalene nerve blocks are additional alternatives to procedural sedation and intra-articular lidocaine injection.



  • Many reduction maneuvers exist. The most common are described here.



  • Traction/countertraction technique (Figure 1.22)




    • With the patient in a supine position, have an assistant wrap a sheet around the waist, through the patient’s axilla, and across the patient’s chest to provide counter traction. Alternatively, the patient can be secured to a stationary object if no assistant is available.



    • The operator then applies axial traction to the patient’s arm with a sheet wrapped around his or her own waist and the patient’s forearm with the elbow bent to 90°.



    • Successful reduction is usually indicated by a soft, palpable clunk and return of mobility.



  • Scapular manipulation technique (Figure 1.23)




    • This is most easily accomplished with the patient prone but can also be performed with the patient seated.



    • In the seated position, brace the uninjured shoulder firmly against a rigid support like a wall or the raised head of a hospital stretcher.



    • Have an assistant face the patient and gently raise the wrist of the affected arm until the shoulder is flexed to 90°.



    • The assistant then places the palm of his or her free hand against the midclavicular area of the injured shoulder for stabilization and gently puts anterior traction on the patient’s arm.



    • While forward traction is applied, the operator manipulates the scapula by adducting the inferior tip using thumb pressure and stabilizing the superior aspect with the upper hand.



    • In a prone position, have an assistant apply downward traction to the affected arm or use 5–10 pounds of hanging weight for traction prior to manipulating the scapula as described earlier.



  • Stimson or hanging weight technique (Figure 1.24)




    • This technique requires continuous patient observation.



    • Place the patient in a prone position.



    • Hang the affected arm over the edge of the bed with 10 pounds of weight for traction.



    • Spontaneous reduction usually occurs within 10–20 minutes.



    • If reduction is not accomplished, use the prone scapular manipulation technique.



  • After successful reduction the patient will require immobilization with a sling, sling and swathe, or shoulder immobilizer (Figure 1.25).



  • Significant controversy exists regarding the type and position of immobilization and duration of immobilization.



  • Studies have suggested that immobilization in external rotation (Figure 1.26) increases contact force between a Bankart lesion and the anterior glenoid rim, possibly influencing healing. In another study, decreased rate of recurrence (26 vs. 42 percent) was found following immobilization in external rotation compared with internal rotation; however, both remained high and noncompliance complicates treatment (53 vs. 72 percent).4



  • Patients should be counseled on non-weight bearing of the arm during the initial immobilization treatment phase.



  • For pain control, NSAIDs are the first line of treatment for pain and inflammation.



  • Providers might also consider adjunctive treatment with acetaminophen and narcotic pain relievers in certain cases.



  • Cold treatment modalities might also provide pain relief for patients.



  • Patients may be discharged safely after successful reduction of their shoulder dislocation.



  • Definitive treatment will most likely require rehabilitation and may include surgical stabilization.





Figure 1.22. Traction–countertraction shoulder reduction technique.





Figure 1.23. Scapular manipulation technique for shoulder reduction.





Figure 1.24. Stimson hanging weight technique for shoulder reduction.





Figure 1.25. Shoulder sling.





Figure 1.26. Shoulder external rotation brace.



Disposition



  • Patients may be discharged safely after successful reduction of their shoulder dislocation.



  • An orthopedic surgery consult is indicated when ED providers are unable to perform a successful reduction, a fracture is present, or there is neurologic or vascular compromise.



  • Some patients may require admission if one of these complications is present.



  • Uncomplicated shoulder dislocation patients should follow-up with an orthopedic or sports medicine specialist within 3–5 days after discharge.




    • It is important to encourage close outpatient follow-up to ensure reassessment and avoid prolonged immobilization, which can lead to frozen shoulder (adhesive capsulitis), especially in older patients.



  • Return to work or sports occurs when the patient has full range of motion and near symmetric strength.



Complications



  • Several complications from shoulder dislocation are possible.




    • If attempts at closed reduction fail or signs of neurovascular injury develop, patients may require closed or open reduction in the operating room under general anesthesia.



    • Reduction injuries can occur, and it is important to use the least amount of force during reduction to avoid creating or exacerbating existing fractures, nerve and vascular injuries.



    • In patients greater than 40 years old, the risk of rotator cuff tear occurring with shoulder dislocation is significant increased, up to 40 percent in those older than 60.



    • Failure to recognize neurologic or vascular injury can lead to significant morbidity.



    • Patient noncompliance can lead to increased risk of recurrent dislocation.



    • Recurrent dislocations can lead to development of osteoarthritis.



    • Younger patients are more susceptible to recurrent dislocation.



    • While it is important to immobilize the affected shoulder initially, the patient should also be warned about complications of prolonged immobilization.



Pediatric Considerations



  • Shoulder dislocations in general are rare in children.



  • Most often they occur near the time of skeletal maturity in adolescents participating in contact sports.



  • Children have weaker epiphyseal growth plates that are more likely to fracture before dislocation occurs.



  • Chronic instability can occur in pediatric patients and is often due to an underlying connective tissue disorder (e.g., Marfan and Ehler–Danlos syndromes) or multidirectional instability.



  • On examination the shoulder may be unstable in several planes and these patients may demonstrate multiple lax joints.



Pearls and Pitfalls



  • Ensure patient’s pain is controlled and muscles are relaxed prior to attempting reduction.



  • In patients with recurrent dislocation, ask what reduction method has been successful in the past.



  • When choosing a reduction method, consider patient volume, staffing, and available equipment.



  • Consider intra-articular lidocaine injection as a first line option for reduction.



  • Use the minimum amount of force necessary during reduction to avoid causing new injury or exacerbating an existing one.



  • In elderly and pediatric patients, use extra caution during reduction and avoid causing friction injury to skin if sheets or straps are utilized.



  • Always consider alternative diagnoses, like coexisting cervical spine injury.



  • Other disorders such as myocardial infarction and splenic rupture can present with shoulder pain.7



Posterior Shoulder Dislocation



General Description



  • Posterior shoulder dislocation results from glenohumeral dissociation where the humeral head is displaced posteriorly.




    • Posterior shoulder dislocation is an uncommon injury, accounting for less than 4 percent of shoulder dislocations.



    • Most of these injuries will reduce spontaneously unless there is an associated fracture.8



    • These injuries are commonly missed initially (up to 80 percent) by treating physicians and diagnosis within six weeks of injury is considered acute.



    • Reverse Hill–Sachs and Bankart lesions are common injuries associated with posterior shoulder dislocations.



Mechanism



  • The mechanism of injury is traumatic, usually occurring after a direct force to the anterior shoulder or a force directed posteriorly on an adducted, flexed, and internally rotated upper extremity.



Presentation



  • Common historical features include direct blow to the anterior shoulder, seizure, electrocution, high-speed motor vehicle accident, and fall on an outstretched arm.



Physical Exam



  • On physical exam, findings are less obvious than in anterior dislocation.




    • Patients generally hold their arm internally rotated and tight at their side.



    • Patients will be unable to actively or passively externally rotate or abduct their arm.



    • Fullness may be palpated posteriorly.



Essential Diagnostics



  • Essential imaging includes a shoulder trauma series.




    • The shoulder may appear normal on the AP view.



    • An axillary or Y view is required for diagnosis.



    • Abnormalities include loss of the normal elliptical overlap between the glenoid rim and humeral head on the AP view, and loss of normal alignment at the glenohumeral joint on the axillary view(Figures 1.27 and 1.28).



    • A “lightbulb sign” may be present on the AP view.




      • This occurs when the humerus dislocates and internally rotates in posterior shoulder dislocation, causing the head contour to resemble a lightbulb when viewed from the front.9 (Figure 1.29)



      • If x-ray is not diagnostic, consider CT for definitive diagnosis.





Figure 1.27. AP radiograph of a patient with posterior shoulder dislocation.





Figure 1.28. Axillary x-ray view in a patient with posterior shoulder dislocation and associated reverse Hill–Sachs lesion.





Figure 1.29. Abnormal AP x-ray view demonstrating a “lightbulb sign” in a patient with posterior shoulder dislocation.


Courtesy of Lorna Breen, MD, New York.


ED Treatment



  • ED treatment is similar to anterior shoulder dislocation. A traction/countertraction technique should be used to achieve reduction.




    • The patient is placed in a supine position and a sheet is fixed around an assistant’s waist or a stationary object and wrapped around the patient’s chest through the axilla.



    • The operator then will loop a sheet around his or her waist and provide traction on the patient’s forearm with the elbow flexed to 90°.



    • Traction is applied smoothly and firmly with the shoulder held in adduction and internal rotation.



    • The assistant can provide gentle pressure on the humeral head in a posterior and lateral direction to disengage it from the glenoid.



    • After the humeral head is disengaged, the arm can be externally rotated with caution as humeral fracture can occur if the humerus is not completely disengaged from the glenoid.



Disposition



  • Post-reduction treatment and disposition is identical to anterior shoulder dislocation and should include radiographic imaging, repeat exam with careful attention to neurovascular exam, immobilization, and follow-up instructions.



Complications



  • Complications from posterior shoulder dislocation include the following:




    • Humerus fracture



    • Acute redislocation



    • Avascular necrosis



    • Posttraumatic osteoarthritis



    • Joint stiffness and functional limitation



Pediatric Considerations



  • Posterior shoulder dislocation in pediatric patients is extremely rare and has not been well studied.



Pearls and Pitfalls



  • Making the correct diagnosis is critical in posterior shoulder dislocation.



  • A complete shoulder trauma x-ray series is essential for diagnosis and includes AP, axillary, and Y views.




    • An axillary view is essential to rule out a posterior shoulder dislocation, and if needed, help the x-ray technician to achieve appropriate patient positioning.



  • Chronic posterior dislocation and complex fracture dislocation will likely require open reduction and internal fixation or humeral head replacement.



  • Intra-articular lidocaine injection is more difficult to perform in posterior shoulder dislocation, but can be used by experienced providers.



  • Smooth, firm traction is required for successful reduction. Providers should not become impatient and use excessive force or impatient maneuvers.



  • Impatience or excessive force can lead to increased likelihood of complications.



  • Aftercare must include complete neurovascular examination and postreduction radiographs.



  • Seek input from orthopedic surgery consultant, as this injury is rare.



Inferior Shoulder Dislocation (Luxatio Erecta)



General Description



  • Inferior shoulder dislocation is a rare but serious type of shoulder dislocation.



Mechanism



  • The mechanism of injury is hyperabduction of the arm where the neck of the humerus is leveraged against the acromion and the humeral head is forced out inferiorly.



  • This requires significant force, such as during a motor vehicle accident.



Presentation



  • Patients will present with an obvious visual dislocation with the arm stuck overhead, and will complain of severe pain and inability to move the shoulder.



Physical Exam



  • On exam the patient’s shoulder will be locked in abduction with their arm held against or behind their head.




    • The dislocated humeral head may be palpable along the lateral border of the chest wall.



Essential Diagnostics



  • A complete shoulder trauma x-ray series including AP, axillary, and Y views is essential due to the high incidence of associated fractures.




    • The humeral shaft will be seen parallel to the spine of the scapula with the humeral head sitting inferior to the glenoid (Figure 1.30).





Figure 1.30. X-ray image demonstrating luxatio erecta. Note the abducted arm with the humeral head dislocated inferiorly.


Courtesy of Trevor Lundstrom, MD, Birmingham, Alabama.


ED Treatment



  • ED treatment is similar to anterior and posterior shoulder dislocation. An axial (in-line) traction or two-step method should be utilized for reduction.



  • To perform the axial traction method, place the patient in a supine position. The operator should be at the patient’s head on the affected side.




    • An assistant can provide countertraction using a sheet wrapped around the waist and across the patient’s chest and above the affected shoulder.



    • The operator then applies axial traction in line with the abducted arm.



    • Increase the degree of abduction and apply cephalad pressure to the humeral head to assist in reduction.



    • After the reduction the arm should be immobilized in full adduction and supination.



  • The two-step reduction method requires converting the inferior dislocation to an anterior dislocation (step one) then reducing the anterior dislocation (step two).




    • With the patient supine, the operator stands at the patient’s head on the affected side.



    • The hand closest to the patient is placed on the lateral aspect of the patient’s mid-humerus with the other on the medial condyle.



    • The operator pushes anteriorly with the hand on the mid-humerus and pulls posteriorly with the hand on the medial condyle. This will bring the humeral head into an anterior position.



    • Next, adduct the patient’s arm and move the hand on the medial condyle to grasp the wrist.



    • With the arm in adduction, externally rotate the shoulder by pulling on the wrist.



    • After reduction is accomplished, immobilize the arm in adduction and supination.10



Disposition



  • Post-reduction treatment and disposition is identical to anterior and posterior shoulder dislocation and should include radiographic imaging, repeat exam with careful attention to neurovascular exam, immobilization, and follow-up instructions.



Complications



  • Complications of inferior shoulder dislocation include:




    • Avulsed capsule



    • Rotator cuff tear



    • Fracture of the acromion, clavicle, inferior glenoid fossa, or greater tuberosity



    • Neurovascular injury including brachial plexus injury



    • Vascular injury including axillary vein thrombosis11



Pediatric Considerations



  • There is limited literature regarding inferior shoulder dislocation in pediatric patients. Evaluation and treatment should follow that for adult patients.



Pearls and Pitfalls



  • 80 percent of patients with inferior shoulder dislocation will have associated fracture of the greater tuberosity or rotator cuff tear.



  • 60 percent will have neurologic compromise and 3 percent will have vascular injury.



Acromioclavicular Joint Injuries



General Description



  • AC joint sprain and separation occurs from trauma to the joint and the surrounding AC ligaments and coracoclavicular (CC) ligament. It is commonly referred to as a separated shoulder.



  • In adults, the normal width of the AC joint is 1–3 mm.




    • May be wider in children or adolescents and narrower in older adults.



  • There are six types of injuries classified by the Rockwood classification system:




    • Type I: Ligament sprain without tearing or rupture of ligaments



    • Type II: AC ligaments are torn and the CC ligaments are sprained.



    • Types III–VI: AC and CC ligaments are torn and further classification is based upon direction of displacement of the distal clavicle.



Mechanism



  • The mechanism of injury is typically impact from a collision or from a fall onto the shoulder with the arm in the adducted position.



  • This type of injury will cause a sprain or disruption of the AC ligaments first, followed by the CC ligament.



  • Indirect injury to the AC joint can occur, for example, from a fall on an outstretched hand.




    • These injuries will usually only affect the AC ligaments and spare the CC ligament.



Presentation



  • The patient with AC joint injury will typically present complaining of shoulder pain that localizes to the AC joint.




    • They will often splint the arm in an adducted position and will be hesitant to range the shoulder when asked.



    • There may be an obvious deformity of the shoulder, depending on the severity of injury.




      • This injury may be confused with a shoulder dislocation.



Physical Examination



  • On physical examination, an abnormal contour of the shoulder may be present when compared to the contralateral side.




    • On inspection, bruising, swelling, and tenting can all be noted near the AC joint.



    • Patients will have significant tenderness at the AC joint.



    • To assess for stability of the AC ligaments, attempt to translate the clavicle in an anterior-posterior direction.



    • Vertical stability confirms the integrity of the CC ligament and is tested by moving the clavicle in the cephalad and caudal directions.



    • The crossover test will be positive in these patients.



    • Neurovascular injury is possible, and one should perform a complete neurovascular examination of the affected extremity.



Essential Diagnostics



  • Essential diagnostics include a shoulder trauma x-ray series.




    • An AP view is necessary and should include both clavicles and shoulders.



    • An axillary view will help to assess the anterior posterior displacement of the clavicle (important for diagnosing type IV injuries).



    • Stress views are generally not required in the ED setting.



  • There are six types of ligamentous injuries to the AC joint (Figure 1.31):




    • Type I: X-rays will be normal.



    • Type II: X-rays will demonstrate slight widening of the AC joint and the distal clavicle may be slightly elevated compared to the contralateral side.



    • Type III: X-rays will show significant increased displacement of the distal clavicle as well as widening of the CC space.



    • Type IV: Axially x-ray will show posterior displacement of the clavicle.



    • Type V: X-rays will show significant increased displacement of the distal clavicle as well as of the CC space.



    • Type VI: These types of injuries are extremely uncommon. On x-ray the distal clavicle will be visualized in a subcoracoid or subacromial position.





Figure 1.31. Classification of ligamentous injuries to the acromioclavicular joint.



ED Treatment



  • The type of injury sustained drives treatment in the ED.



  • Type I: X-rays will be normal. Advise patients on rest, ice, and use of a sling for 7–10 days.



  • Type II: X-rays will demonstrate slight widening of the AC joint. Advise patients to use a sling for up to two weeks. They will often require rehabilitation in physical therapy.



  • Type III: X-rays will show significant increased displacement with stress views. Definitive treatment is usually nonsurgical but surgical repair may be advised by some surgeons, especially for athletes or laborers.



  • Type IV: Axillary x-ray will show posterior displacement of the clavicle. If closed reduction is possible, treat like a type III injury, otherwise these patients will require emergency orthopedics consult for surgical reduction and repair.



  • Type V: Gross displacement is noted on x-ray. Patients will require emergency orthopedic surgery consult. Definitive treatment is generally with open reduction and internal fixation.



  • Type VI: These types of injuries are extremely uncommon. On x-ray the distal clavicle will be visualized in a subcoracoid or subacromial position. If closed reduction is possible, treat like a Type III injury, otherwise these patients will require ORIF.



  • Fracture of distal clavicle associated with rupture of the CC ligament often will require surgical intervention.



Disposition



  • Patients with Type I, Type II, and Type III injuries can be safely discharged from the ED. They will require routine follow-up with their primary care provider or in the orthopedic or sports medicine clinic.



  • Patients with Type IV, Type V, and Type VI injuries and injuries associated with fractures will require orthopedic consultation and disposition.



  • NSAIDs are first line of treatment for pain control. More significant injuries may require opiates for analgesia.



  • Patients may return to work or sports once they have normal strength, and full pain-free range of motion.



Complications



  • Complications may occur with both nonsurgical and surgical treatment of AC joint injury.




    • Complications of nonoperative treatment include skin breakdown as well as osteolysis at the distal clavicle and degenerative changes at the AC joint.



Pediatric Considerations



  • In pediatric patients, consider performing a Zanca (AC joint) view (Figure 1.32) to exclude associated fractures.




    • A Zanca view is an AP view with the beam directed toward the AC joint with 10°cephalic tilt, with the voltage idealized for soft tissue to avoid over penetration.



  • Pediatric injuries are classified using the Dameron and Rockwood classification system, which is very similar to the Rockwood adult classification system.



  • Treatment for pediatric injuries essentially follows that for adult injury.





Figure 1.32. A normal Zanca view in an adult patient.



Pearls and Pitfalls



  • Concomitant injuries do occur and can be masked by the more painful AC joint injury.



  • Stress views are generally not obtained in the ED.12, 13



Sternoclavicular Joint Injury



General Description



  • Sternoclavicular (SC) joint dislocation occurs when the medial end of the clavicle becomes displaced anteriorly or posteriorly relative to the sternum.



Mechanism



  • The most common mechanism of injury is a direct blow to the anterior chest, such as a steering wheel injury that occurs during a motor vehicle accident.




    • This typically results in posterior SC joint dislocation.



    • Posterior SC joint dislocation can be associated with occlusion of the superior vena cava or esophagus.



  • A lateral or posterior force to the shoulder girdle will result in an anterior SC joint dislocation.




    • This type of dislocation is generally benign.



  • Scapulothoracic dissociation occurs as a result of severe high-energy trauma and can cause complete disruption of the SC joint.




    • These injuries can be associated with axillary artery and brachial plexus injury.



Presentation



  • On presentation, patients will localize pain with possible deformity at the SC joint after traumatic injury.




    • Patients may complain of dysphonia, dysphagia, or dyspnea.



Physical Exam



  • Physical exam will demonstrate soft tissue swelling and tenderness at the medial clavicle.




    • Patients may laterally flex their neck toward the affected side to relieve pressure on the SC joint.



    • In posterior dislocation, there will be a palpable step-off at the lateral manubrium.



    • Swelling and a prominent medial head of the clavicle may be palpable in anterior SC joint dislocation.



    • SC joint sprain will present with mild to moderate pain at the SC joint without instability on physical exam.



Essential Diagnostics



  • Essential radiographic views include AP, and serendipity or tilt views.




    • In a serendipity view the beam is aimed at the manubrium with a 40°cephalic tilt (Figure 1.33).



    • CT is the most reliable imaging modality to determine dislocation.



    • CTA and MRA are useful in assisting with determining the direction of dislocation and in evaluation for vascular injury.





Figure 1.33. A normal serendipity x-ray view.



ED Treatment



  • Treatment for SC joint sprain is conservative with a sling for comfort, analgesia as needed, and cold therapy. These injuries will generally resolve in one week.



  • A SC joint subluxation can occur and treatment follows that for SC joint sprain. Sling immobilization will be required for a longer duration.



  • Reduction is not typically needed for anterior dislocation.




    • Closed reduction may be needed for patients who engage in strenuous activity involving the upper extremities.



    • These patients may be safely discharged from the ED.



  • Closed reduction can be attempted in the ED for patients with posterior dislocation without evidence of airway, vascular, or esophageal injury.




    • Procedural sedation is recommended to accomplish these maneuvers.



    • General anesthesia is usually required for patients with severe pain and muscle spasms.



    • If reduction is unsuccessful, orthopedic surgery and thoracic surgery consults will be required for open or closed reduction in the operating room.



  • Classic method (abduction-traction technique) (Figure 1.34)




    • To perform this reduction maneuver, place a rolled-up towel or sandbag posteriorly between the shoulder blades with the patient positioned supine.



    • Traction is applied to the abducted arm against countertraction in an abducted and slightly extended position.



    • Direct pressure over the medial clavicle may reduce the joint in anterior dislocations.



    • Successful reduction is indicated by an audible snap or pop.



    • For posterior dislocations, manual manipulation of the medial clavicle may be necessary to dislodge it from behind the manubrium.



    • For difficult posterior dislocations, the medial clavicle may need to be prepared sterilely, followed by use of a towel clip to grasp the medial clavicle and lift it into a normal position.



  • Buckerfield and Castle technique (adduction-traction technique)




    • In this method, place a rolled towel between the supine patient’s shoulder blades.



    • The operator applies traction to the adducted arm while an assistant applies a posteriorly directed pressure to the shoulder.



    • This will lever the clavicle over the first rib into its normal position.14



  • In both of these techniques, the medial end of the clavicle may need to be manipulated using a towel clip or fingers.



  • Following reduction, the arm should be placed in a figure-of-eight brace (Figure 1.35) for immobilization.




    • Alternatively a Velpeau bandage or sling may be utilized.15



  • NSAIDs and cold therapy are first-line treatment for pain. More severe injuries may require opioid analgesics.






A. Patient position with sandbag and traction in abduction and slight extension.





B. Manual manipulation of the medial end of the clavicle in posterior dislocation.





C. Use of a towel clip for difficult posterior dislocations.



Figure 1.34. Technique for closed reduction of the sternoclavicular joint.





Figure 1.35. Figure-of-eight brace, also called a clavicle strap.



Disposition



  • Generally, patients with anterior SC joint dislocation and uncomplicated posterior SC joint dislocation can be discharged from the ED.



  • If attempts at posterior SC joint dislocation reduction fail or if complicated SC joint dislocation is present, orthopedic surgery and/or thoracic surgery consult is warranted in the ED.



  • Routine sports medicine or orthopedic surgery follow-up is necessary after anterior SC joint dislocation.



  • After reduction, patients with posterior SC joint dislocation require close orthopedic surgery and/or thoracic surgery follow-up.



  • Patient may recover quickly from SC joint sprain, subluxation, and anterior dislocation. Return to work or sports can occur when patients regain full pain-free range of motion and near symmetric strength.




    • Patients with posterior SC joint dislocation will take longer to heal.



    • Recurrent instability may delay or preclude return to pre-injury levels of activity.

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Sep 1, 2020 | Posted by in SPORT MEDICINE | Comments Off on Chapter 1 – Shoulder
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