Chapter 2 – Elbow




Chapter 2 Elbow


Christopher Hogrefe , Ross Mathiasen , and Timothy W. Thomsen



Background/Epidemiology




  • The elbow is a relatively complex hinge joint that permits not only flexion and extension but also supination and pronation (Figure 2.1).




    • It is this combination of movements/articulations that can lead to instability of the elbow.



  • An estimated 15% of ED visits for upper extremity musculoskeletal injuries involve the elbow/forearm.1



  • The underlying mechanisms contributing to elbow injuries are varied, although certain mechanisms are more common.




    • Falls on outstretched hands (FOOSH)



    • Motor vehicle collision



    • Specific sports-related activities




      • Baseball pitching/throwing



      • Football passing



      • Tennis serving



      • Volleyball spiking



  • The incidence of sports-related elbow injuries continues to rise.




    • This is driven by an increase in sport participation, particularly by the pediatric population.



    • Overuse and/or early sport specialization can result in acute injuries.



  • Injuries to the elbow include fractures, dislocations, muscular/tendon ruptures, and other soft tissue injuries (bursitis, epicondylitis, etc.).




    • The incidence of each injury varies widely, particularly based on age (i.e., adult vs. pediatric).



  • Fractures are the most common significant elbow injury presenting to the ED, regardless of age group.




    • Historically, fractures of the elbow are one of the most commonly missed fractures by ED providers evaluating plain films.



    • The miss rate is as high as the miss rate for phalanx fractures despite the fact that phalanx fractures are three times more prevalent in one study.2





Figure 2.1. A human cadaver elbow.



Anatomical Considerations/Pathophysiology



Bony Anatomy




  • The elbow joint itself features three bony constructs: the humerus, radius, and ulna (Figure 2.2).



  • The medial and lateral epicondyles of the elbow arise from the widened distal humerus.



  • The capitellum is the cartilaginous component of the distal humerus, which articulates with the radial head.




    • This junction facilitates supination and pronation of the forearm.



  • The cartilaginous trochlea resides at the medial condyle articular surface of the humerus.




    • The trochlea articulates with the ulna.



    • It permits flexion and extension of the elbow.



  • Of note, the radial head is angulated 15° away from the radial tuberosity by design.




    • This facilitates up to 180° of rotation of the forearm.



  • The ulna features the coronoid process to articulate with the humerus and the olecranon posteriorly.




    • Disruption of the coronoid and/or the olecranon process can be problematic for maintaining elbow stability.



    • A fracture of the coronoid process without an intact radial head can result in elbow instability even with intact ligaments.





Figure 2.2. The bony anatomy of the elbow.



Muscles




  • A significant number of muscles originate, insert, and/or pass through the elbow.



  • Flexion of the elbow is produced by the brachialis, brachioradialis, and biceps brachii.



  • Extension of the elbow is primarily performed by the triceps.




    • The anconeus, found lateral to the olecranon process, also plays a small role in extension. While trivial, some controversy exists as to whether this muscle is actually part of the triceps brachii or a posterior component of the forearm.



  • Forearm pronation is performed by the pronator teres.




    • The medial epicondyle serves as the origin of this muscle.



    • The pronator quadratus also aids in pronation.



  • Supination of the forearm is handled by the biceps and supinator muscles.




    • The supinator originates at the lateral epicondyle.



  • The muscles that control flexion and extension of the wrist also originate at the elbow. These are listed here for completeness but discussed in more depth elsewhere.




    • The medial wrist/finger flexors, stemming from the medial epicondyle, include:




      • Flexor carpi radialis



      • Palmaris longus



      • Flexor carpi ulnaris



      • Flexor digitorum superficialis



    • Originating from the lateral epicondyle, the muscles responsible for wrist/finger extension are:




      • Extensor carpi radialis longus



      • Extensor carpi radialis brevis



      • Extensor digitorum



      • Extensor digiti minimi



      • Extensor carpi ulnaris



Ligaments




  • The ulnar collateral ligament (UCL) stabilizes the elbow in the setting of valgus stress.




    • It is localized along the medial aspect of the elbow, originating at the medial epicondyle and inserting at the coronoid process.



    • This is frequently referred to as the “Tommy John” ligament, often injured due to repetitive stress from overhead throwing activities.



    • Some refer to the ligament as the medial collateral ligament of the elbow.



    • It is a bundled ligament with an anterior and posterior aspect.




      • The anterior bundle is tight in extension, akin to the ACL of the knee.



      • The posterior bundles are tightest in flexion.



    • The UCL is maximally stressed with the elbow flexed between 30° and 120°.3



  • The radial collateral ligament (RCL) is actually a complex of ligaments.




    • It functions to provide stability against varus stress at the elbow.



    • Primarily composed of the RCL, this complex also includes the annular ligament, accessory collateral ligament, and the lateral ulnar collateral ligament (or LUCL).



    • This ligament complex is rarely injured, particularly in athletes.



  • The annular ligament supports the radioulnar joint.




    • Its flexibility permits the radius to rotate freely with forearm rotation.



    • Additionally, it is this ligament that “fails” to keep the radial head articulated in patients with a nursemaid’s elbow.



Neurovascular Structures




  • The median nerve (Figure 2.3) innervates virtually all of the forearm flexors.




    • It passes along the anterior elbow.



    • Covered by the bicipital aponeurosis, it passes between the pronator teres heads.



    • In the elbow, it provides sensation anteriorly and medially.



  • Amongst other muscles, the radial nerve (Figure 2.3) innervates the triceps, brachioradialis, supinator, and extensors of the forearm/hand.




    • It runs between the brachialis and brachioradialis in the anterior elbow.



    • The radial nerve also provides sensation to the posterior medial elbow.



  • The ulnar nerve (Figure 2.3) innervates the remaining forearm flexors.




    • Specifically, it innervates the flexor carpi ulnaris and the flexor digitorum profundus.



    • The ulnar nerve passes the posterior medial epicondyle and runs through the cubital tunnel.



    • It has no sensory role at/near the elbow.



  • The brachial artery courses though the anterior elbow as well, medial to the distal biceps tendon.




    • It runs along the course of the median nerve in the elbow.



    • The brachial artery bifurcates in the cubital fossa to form the radial artery (lateral aspect) and ulnar artery (medial aspect) in the forearm.





Figure 2.3 The median, radial, and ulnar nerves as they pass through the elbow.


Courtesy of the AO Foundation.


Focused Physical Examination



Visual Inspection




  • Appreciate any gross visual deformities, such as:




    • Erythema



    • Ecchymosis



    • Swelling (diffuse or focal)



    • Atrophy



  • The carrying angle of the arm should be noted.




    • It is the bisection of a line drawn down the humerus and a line that runs along the mid-forearm.



    • The normal carrying angle varies but is generally between 5–15°.4



    • This must be assessed with the elbow in extension.



    • An increased angle (cubitus valgus) suggests a lateral epicondyle fracture.



    • A decreased angle (cubitus varus) may indicate a supracondylar fracture.



  • Pay attention to the patent’s position of comfort (e.g., flexed and abducted).




    • An elbow joint holds the greatest volume at 45° of flexion; holding it in this position may indicate a joint effusion.5



Palpation




  • The key elbow structures to palpate include:




    • Distal humerus



    • Medial epicondyle



    • Lateral epicondyle



    • Olecranon/olecranon bursa



    • Radial head



    • Distal biceps tendon



    • Distal triceps tendon



Range of Motion




  • The flexion/extension arc of motion of the elbow is roughly 0–140° degrees.




    • Some overhead athletes (e.g., baseball pitchers) may have a flexion contracture of up to 10° in the dominant upper extremity.6



    • Gymnasts, conversely, may have motion that exceeds these limits.



    • Those with significant muscle mass (football lineman, body builders, etc.) may have generally decreased motion.



  • Supination and pronation should allow for 180° of motion at the elbow.




    • This motion should be assessed with the patient’s elbow flexed to 90° and held at the waist.



    • Start with the thumb pointed upward.




      • Rotation of the palm to face upward is supination.



      • Rotation of the palm to face downward is pronation.



    • Measure the full distance of the arc, noting which direction of the rotation may be lacking.



    • Utilize the contralateral side if necessary to compare the arc of supination/pronation.



Neurovascular Examination




  • Sensation about the elbow is supplied by four different nerves (Figure 2.4).




    • The lateral distal humerus down to the level of the elbow is supplied by C5 (axillary nerve).



    • The lateral forearm is supplied by C6, which is a branch of the musculocutaneous nerve.



    • Sensation of the medial forearm is provided by the medial antebrachial cutaneous nerve (C8).



    • T1 produces the brachial cutaneous nerve, providing sensation to the distal, medial humerus region.



  • Injury to the median, radial, and/or ulnar nerves may be assessed via a thorough evaluation of the sensation of the hand, which is discussed elsewhere in this text.



  • The brachial artery is the primary artery passing through the elbow.




    • It can be assessed with palpation medial to the distal biceps tendon.



  • There are three primary reflexes to evaluate at or near the elbow.




    • For each test, position the patient’s arm flexed to roughly 70° and support the arm with your own extremity.



    • Biceps reflex (C5): Place your thumb over the distal biceps tendon and strike the thumb to elicit the biceps reflex.



    • Brachioradialis reflex (C6): Strike the distal radius near the insertion of the brachioradialis muscle and look for a radial jerk.



    • Triceps reflex (C7): Encourage the patient to relax the arm and tap the triceps tendon over the olecranon fossa.





Figure 2.4. The cutaneous innervation of the upper extremity.



Special Tests




  • The Hook test evaluates for a ruptured distal biceps tendon. (Figure 2.5)




    • With the forearm supinated, attempt to hook the distal biceps tendon with your index finger from the lateral aspect.



    • A positive test occurs when there is no cord-like structure to hook.



    • The sensitivity and specificity of this test is 100%; MRI is 92% and 85%, respectively.7



  • Tennis elbow test is utilized to evaluate for lateral epicondylitis.




    • The shoulder is flexed to approximately 60° with the elbow extended, forearm pronated, and wrist extended to 30° while making a fist.



    • The examiner then applies pressure to the dorsum of the hand.



    • A positive test reproduces pain at the extensor carpi radialis brevis tendon.



  • Cozen’s test may also assess for lateral epicondylitis. (Figure 2.6)




    • Place the affected elbow in 90° of flexion with the wrist in flexion, pronation, and radial deviation.



    • The provider should place one thumb over the lateral epicondyle.



    • Ask the patient to extend the wrist against resistance.



    • A positive test reproduces pain at the lateral epicondyle.



  • Golfer’s elbow test may assist in identifying patients with medial epicondylitis.




    • The affected elbow should be slightly flexed with the forearm pronated and the fingers fully flexed.



    • With one hand palpating the medial epicondyle, passively supinate the forearm while extending the elbow and the wrist.



    • Pain at the medial epicondyle signals a positive test.



  • The modified milking maneuver may be utilized to assess for injuries to the UCL. (Figure 2.7)




    • The forearm of the affected extremity should be supinated and the elbow flexed to 70°, which creates the valgus laxity.



    • The shoulder should be abducted and in maximum external rotation.



    • The examiner then pulls on the patient’s thumb to create a valgus stress.



    • Pain, laxity, and/or apprehension about the medial elbow reflect a positive test.



  • The moving valgus stress test may also be utilized to assess the integrity of the UCL. (Figure 2.7)




    • The shoulder should be held in 90° of both abduction and external rotation.



    • A constant valgus stress is applied to the fully flexed elbow.



    • The elbow is then extended quickly while the force is maintained.



    • A positive test occurs when pain is reproduced at the medial elbow, especially between 120° and 70°.



    • One should also assess for laxity compared to the contralateral elbow.



    • This test has been shown to have a sensitivity of 100% and a specificity of 75%.8



  • To assess for RCL injuries, a varus stress test can be performed. (Figure 2.7)




    • Flex the affected elbow to approximately 20° with the forearm supinated.



    • A varus force is then applied about the elbow by holding the humerus in one hand and the ulna in the other to create a fulcrum.



    • A positive test results in pain, laxity, and/or apprehension at the lateral elbow.





Figure 2.5. A negative hook test.





Figure 2.6. Cozen’s test.










Figure 2.7. Special tests for evaluating the elbow (left to right): modified milking maneuver, moving valgus stress test, and varus stress test.



Differential Diagnosis-Emergent and Common Diagnoses



Elbow Dislocations



General Description



  • Elbow dislocations are defined as disruptions of the articulation of the distal humerus, proximal radius, and proximal ulna.



  • The elbow is the second-most commonly dislocated major joint (after the shoulder).




    • The rate of elbow dislocation is up to 6.1 cases per 100,000 people.9



    • Such injuries represent 10–25% of all elbow injuries.10



  • These injuries can occur in an anterior fashion, which is rare, or a posterior variation, which accounts for up to 90% of such injuries.11 (Figure 2.8)




    • Some further divide the dislocations into simple (soft tissue involvement only) vs. complex (associated with a fracture).




Table 2.1 Emergent and Common Diagnoses in the Emergency Department














































Emergent Diagnoses Common Diagnoses
Elbow Dislocations Nursemaid’s Elbow
Displaced Radial Head Fractures Elbow Subluxation
Supracondylar Fractures Occult Radial Head Fractures
Monteggia Fractures OCD Lesion/Little Leaguer’s Elbow
Septic Bursitis Ligamentous Injuries (UCL/RCL)
Septic Arthritis Distal Biceps Ruptures
Compartment Syndrome Distal Triceps Ruptures
Lateral/Medial Epicondylitis
Cubital Tunnel Syndrome
Pronator Syndrome
Olecranon Bursitis
Gout/Pseudogout




Figure 2.8. Posterior dislocation of the elbow without any associated fractures.



Mechanism



  • Most commonly, elbow dislocations are the result of a fall on an outstretched hand (FOOSH) injury, which results in a posterior dislocation.




    • Anterior dislocations can be caused by trauma to the flexed posterior elbow.



    • Medial and lateral dislocations can occur, but they are exceedingly rare.



  • Inquire about sports participation, as it has been reported that 44.5% of elbow dislocations are sports-related.12




    • One study reports a higher incidence in football, rugby, roller skating, ice skating, skateboarding, and wrestling.12



  • Falls, even from standing, and/or motor vehicle collisions may result in elbow dislocations.




    • Falls have been attributed to greater than 80% of elbow dislocations.13



    • The most common location for such a fall is the home (51.5%), vs. the workplace (13.7%).12



Presentation



  • Males are more affected than females, particularly in the 11-year-old to 20-year-old age demographic.12, 13




    • The mean age of the presenting patient is 30.14



  • The nondominant extremity is more commonly affected (60% vs. 40%).15



  • Elbow dislocations may be acute or chronic (more than seven days old).



  • Visual inspection often reveals a gross deformity.



  • The position of comfort for the patient may provide insight into the type of dislocation.




    • A flexed elbow is indicative of a posterior elbow dislocation.



    • An extended, supinated elbow/forearm reflects an anterior elbow dislocation.



Physical Exam



  • Palpation of the elbow may provide insight into the type of elbow dislocation.




    • Posterior dislocations often result in a prominent olecranon.



    • An extended forearm frequently signals an anterior dislocation.



  • An elbow effusion is frequently present.



  • Be sure to assess the skin thoroughly to rule out an open dislocation.



  • Range of motion (ROM) is often severely limited.



  • The neurovascular examination is paramount in these injuries.




    • It is important to clearly document the patient’s neurovascular examination before and after reduction.



    • The most commonly injured artery is the brachial artery.




      • This injury is still exceedingly rare, with a reported incidence in one study of 0.47%.16



    • The median and ulnar nerves should also be carefully assessed.




      • Ulnar nerve palsies occur in 14% of elbow dislocations.17



      • Neuropraxia occurs in 20% of patients.17




        • This typically involves the anterior interosseous branch of the median nerve (thumb flexion) or the ulnar nerve.



      • Radial nerve injuries are rare.



    • Most neurologic deficits are transient.




      • Median nerve entrapment after reduction can occur, more commonly in pediatric patients.



  • Consider compartment syndrome, particularly with significant antecubital fossa swelling.



Essential Diagnostics



  • Anteroposterior (AP) and lateral plain films of the elbow are critical for identifying the type of dislocation and any concomitant fractures. (Figure 2.9)




    • Patients with a shallow olecranon fossa or a prominent olecranon tip are more prone to elbow dislocations.



  • Post-reduction plain films (AP and lateral) are equally essential.




    • They ensure adequate alignment and evaluate for a possible iatrogenic fracture.



  • In patients with complex elbow dislocations, a CT scan of the elbow is appropriate to facilitate reconstruction.




    • Discuss the necessity of this imaging with the orthopedic consultant.



  • Evidence of brachial artery injury on physical examination may necessitate angiography.




    • Given the rarity of this injury, treatment (conservative vs. operative repair) is controversial.18








Figure 2.9. Lateral (left) and AP (right) radiographs of a complex posterior elbow dislocation with a proximal ulna fracture.



ED Treatment



  • Pain control is important, but reduction does not, by definition, require analgesia.




    • These injuries may be reduced on-scene (e.g., the athletic field) without analgesia.



    • Successful reduction may prove sufficient for relieving a patient’s pain.



  • Procedural sedation may be necessary for complicated reductions or to achieve adequate muscle relaxation.



  • Reduction is critical and should be performed as soon as possible.




    • Reduction prior to imaging in the setting of neurovascular compromise is appropriate.



  • There are several described methods for reducing a posterior elbow dislocation. (2.10)




    • Supine Traction/Countertraction: Apply traction to the forearm and countertraction to the humerus while flexing and slightly supinating the elbow.




      • One may need to apply downward pressure on the forearm to free the coronoid from the olecranon fossa.



    • Prone Traction: With the patient’s elbow hanging off the bed/table, apply longitudinal traction to the humerus while the elbow is extended.




      • This may take several minutes to be effective.



      • One may have to manipulate the coronoid process to slide it past the trochlea.



      • Weight (5–10 pounds) may be used to apply the aforementioned traction.



    • One-Person Technique: Place the patient’s arm across the chest while bracing the distal upper extremity; traction is then applied longitudinally at the forearm to allow the coronoid to slide past the trochlea.



  • Anterior elbow dislocations are best reduced by applying downward pressure to the forearm with concomitant anterior pressure to the distal humerus.



  • Confirmation of a successful reduction should include full passive ROM and post-reduction plain films of the elbow.




    • ROM should be smooth and free of locking.



    • Perform gentle moving valgus stress and varus stress testing to ensure stability.



  • The final ED treatment depends upon the patient’s elbow joint stability.




    • If the joint is stable, an upper extremity sling is sufficient.



    • If the elbow feels unstable with pronation, a posterior splint with the elbow at 90° of flexion and the forearm pronated is advised.14




      • A hinged elbow brace locked at 90° of flexion is an appropriate alternative.



    • An unstable joint warrants an orthopedic surgery consultation in the ED.




      • A CT scan may be necessary to further evaluate the joint in advance of possible surgical stabilization.



Disposition



  • In the absence of neurovascular injury, these patients may be discharged to home.




    • Some advocate a two- to four-hour observation period in the ED.19



  • Prompt follow-up with an orthopedic surgeon or sports medicine provider is critical.




    • Ideal follow-up should occur in two to three days, at which time the posterior splint is removed and the patient’s physical examination repeated.



    • Early ROM exercises and/or physical therapy will likely be recommended to decrease the likelihood of stiffness and/or decreased ROM.



  • An inability to reduce the dislocation, neurovascular compromise, and/or concern for compartment syndrome warrant orthopedic consultation and admission.










Figure 2.10. Techniques for reducing a posterior elbow dislocation. From left to right: supine traction/countertraction; prone traction; and the one-person technique.



Return to Work/Sports



  • Patients should not return to activities that stress the elbow (e.g., throwing) until a follow-up appointment is completed.



  • A full return to activity is typically within four to six weeks.




    • However, it may require up to three months for athletes to return to their pre-injury level of participation.14



Complications



  • Recurrent dislocations are rare although persistent instability may be more common than previously thought.




    • 15–30% of patients may have instability symptoms (painful clicking, snapping, clunking, etc.), which are often difficult to appreciate on examination.20



  • Heterotopic ossification has been associated with elbow dislocations.




    • This occurs at a rate of 5–18%.21



    • Prescribing NSAIDs at the time of discharge can reduce the possibility of developing heterotopic ossification.22



  • Compartment syndrome is an associated complication that must be considered.



Pediatric Considerations



  • Due to the relative strength of ligaments/muscles in children compared to bone, this population has a higher prevalence of physeal injuries.



  • While still rare (3%), pediatric patients are more prone to median nerve entrapment in the elbow following a dislocation reduction.23



Pearls and Pitfalls



  • Document a thorough neurovascular examination both before and after reducing the elbow dislocation.



  • Prompt reduction is essential; do not wait for an orthopedic surgeon.



  • Be sure to obtain post-reduction films.



  • Follow-up with an orthopedic surgeon or sports medicine provider within one week, preferably in two to three days, is essential to prevent ROM loss.




    • A fixed flexion deformity will develop if a patient is immobilized for three or more weeks.24



Nursemaid’s Elbow



General Description



  • Nursemaid’s elbow is defined as a subluxation of the radial head.



  • These injuries occur in children ages 1–4, with the peak incidence between ages 2 and 3.25




    • This condition is uncommon in those older than 5 due to the development of the orbicular ligament.



    • However, it has been described in adults.



  • Other colloquial synonyms for this injury include: temper tantrum elbow and Malgaigne’s injury.



Mechanism



  • Typically, this injury is the result of a longitudinal force applied to the forearm. (Figure 2.11)




    • This results in subluxation of the radial head and entrapment of the annular ligament in the radiocapitellar joint. (Figure 2.11)



  • Subluxing the radial head requires pronation of the forearm, which places the radial head in the narrowest plane.



  • Theoretically, it can occur as the result of a fall with the upper extremity trapped between the patient’s trunk and the ground.








Figure 2.11. The classic mechanism precipitating nursemaid’s elbow (left), resulting in subluxation of the radial head and entrapment of the annular ligament (right).



Presentation



  • The left arm is more commonly affected than the right.25



  • At least 80% of cases involve longitudinal traction of a pronated, extended forearm.14



  • The patient will often hold the arm in slight flexion with the forearm pronated (known as the “nursemaid’s position”).



  • A tearful child refusing to utilize the affected upper extremity is frequently observed.



  • Pain in the wrist may be reported.



  • Occasionally, no trauma will be noted; parents may simply report that the patient is not utilizing the upper extremity.



Physical Exam



  • Careful observation can be very beneficial.




    • The patient may be playful but simply avoid the use of the affected extremity.



    • One may witness the patient utilize the shoulder, wrist, and hand without difficulty and/or pain.



  • No ecchymosis and/or swelling is generally appreciated.



  • Flexion and extension of the elbow may be normal; however, supination will be limited or absent.



  • Careful palpation of the anterolateral radial head may reveal a subluxation.



  • Be sure to evaluate the wrist and shoulder of the patient to rule out concomitant injuries.



Essential Diagnostics



  • Plain films of the elbow are not necessary in the proper age demographic with a classic history, as described earlier.



  • In the setting of trauma, AP and lateral plain films of the elbow may be helpful to rule out a concomitant injury.



ED Treatment



  • Reduction should be attempted in the ED.



  • The hyperpronation technique may be more effective and less painful for reducing nursemaid’s elbow.26 (Figure 2.12)




    • Palpate the radial head.



    • Then, gently rotate the forearm into hyperpronation.



    • Slowly fully extend the elbow until maximum extension is achieved.



    • This is 95% effective, compared to 77% for the supination/flexion method.26



  • The supination/flexion technique is also an accepted reduction method.




    • Place a thumb on the radial head.



    • With the other hand on the distal forearm, gently yet firmly fully supinate the forearm.



    • Then flex the elbow to 90° or until maximum flexion is achieved.



    • A palpable and/or audible click should be appreciated.



    • This typically results in immediate pain relief and restoration of full range of motion.



  • After successful reduction, observe the patient for 15 minutes to ensure full function of the affected extremity.26




    • If full function has not returned, a repeated attempt at reduction is recommended.



    • The time to return of normal function may be delayed if the time to treatment is delayed.



  • Reconsider the diagnosis if full function does not return after multiple reduction attempts.




    • Plain films of the elbow should be considered at that juncture.



    • If imaging is negative in the setting of failed reduction attempts, the patient should be placed in a posterior splint and follow-up with an orthopedic surgeon in twenty-four to forty-eight hours.27



  • Post-reduction plain films are not necessary.



  • Immobilization is not generally recommended following a successful reduction.








Figure 2.12. Hyperpronation reduction and supination/flexion reduction of nursemaid’s elbow.



Disposition



  • Formal follow-up is not generally recommended/necessary.



  • Prevention is essential; counsel parents to avoid longitudinal traction in the future.



  • If the patient has a history of recurrent radial head subluxations, a referral to an orthopedist (or pediatric orthopedist) is appropriate.




    • The patient may benefit from a cast for two to three weeks at that time.28



Complications



  • There are few long-term adverse effects of nursemaid’s elbow.



  • The recurrence rate is 27–39%.25, 29



  • In the setting of failed reductions, be sure to consider occult fractures or cartilage injuries.



Pediatric Considerations



  • Nursemaid’s elbow is primarily a pediatric condition.



Pearls and Pitfalls



  • In children less than 6 months old, consider child abuse.



  • If the diagnosis is strongly suspected, try to incorporate a reduction into the physical examination to keep the patient at ease and to promptly alleviate his/her symptoms.



  • Be sure to observe the patient after reduction to ensure a full return to function.



Radial Head Fractures



General Description



  • Radial head fractures are the most common elbow fracture in adults, representing 30% of such fractures.30




    • Such fractures represent up to 5.4% of adult fractures.31



    • They are uncommon in children, representing only 1% of all fractures.32



  • Most radial head fractures are not associated with concomitant injuries.




    • However, this should not preclude further evaluation based on the provider’s clinical suspicion.



Mechanism



  • The most common mechanism of injury is a FOOSH injury.




    • This results in a direct axial load to the elbow.



    • The forearm is usually pronated.



  • A posterior lateral rotary force can cause a radial head fracture, which is often present in an elbow dislocation.



  • A direct blow can also result in this type of fracture, although this mechanism is uncommon and should prompt consideration of other types of elbow fractures.



Presentation



  • Be sure to elicit the specific mechanism of injury, asking specifically about a FOOSH.



  • The typical presentation involves a patient holding the affected arm in abduction near the chest with the elbow flexed.



  • Movement at the elbow (e.g., flexion, extension, supination, and pronation) typically aggravates the patient’s pain.



Physical Exam



  • Observe carefully for ecchymosis and/or swelling over the lateral elbow.



  • Tenderness to palpation over the radial head (distal to the lateral epicondyle) should localize the pain.




    • Passively rotating the elbow in either direction should worsen pain.



    • Crepitance may also be present.



  • Diligently observe and document the patient’s ROM at the elbow (including flexion, extension, supination, and pronation).




    • Be sure to compare to the unaffected elbow, if necessary.



    • Preservation of ROM is up to 97% specific for the absence of a radial head fracture.33



  • It is essential to palpate both the wrist and the forearm.




    • An Essex–Lopresti fracture could be present, which involves a proximal radial fracture in addition to disruption of the radioulnar joint and/or interosseous membrane. (Figure 2.13)



    • This injury results in instability of the forearm.



  • Pay close attention to the stability of the UCL.




    • Perform moving valgus stress testing and/or the modified milking maneuver. (See Figure 2.7 earlier in chapter)








Figure 2.13 An Essex-Lopresti fracture showing a fracture of the proximal radial head (left) and disruption of the radioulnar joint (right).



Essential Diagnostics



  • Plain films of the elbow are critical in evaluating for this injury.



  • A valid clinic decision rule (East Riding Elbow Rule, or ER2) exists to help determine if plain films are necessary.34




    • The absence of the following excludes an acute elbow fracture:




      • Inability to flex the elbow



      • Tenderness over the radial head, olecranon, and/or medial epicondyle



      • Presence of bruising



    • The specificity is poor (24%), but the sensitivity is 100%.



  • AP and lateral radiographs are usually sufficient to make the diagnosis.




    • Radial head views should be obtained if an abnormal fat pad sign (detailed next) is appreciated on standard imaging.



  • Assess the plain films for the fat pad signs. (Figure 2.14)




    • Either the anterior or posterior fat pad sign can be indicative of a fracture in the absence of an obvious cortical disruption.



    • These fat pad signs are the result of a joint effusion and should be considered the result of an intra-articular fracture.



    • The anterior fat pad, also known as the “sail sign,” may represent an occult fracture, especially when it is elevated and resembles a sail, but it is not always abnormal.



    • The posterior fat pad sign is always abnormal and suggests an underlying fracture.



  • The Mason classification, which has been modified over time by Johnston and Morey, may help categorize these injuries based on radiographic findings and guide further management.35




    • Type I: A nondisplaced or minimally displaced fracture.




      • Includes less than 2-mm intra-articular displacement of the fracture.



      • The fragment size must be less than or equal to 30% of the articular surface.



    • Type II: A displaced fracture of the radial head and/or neck




      • The fracture is displaced more than 2 mm.



      • There also must be more than 30% of the articular surface visible.



    • Type III: Severely comminuted fracture of the radial head and/or neck. (Figure 2.15)



    • Type IV: Radial head fracture in the setting of an elbow dislocation.




      • Type IV injuries combined with a coronoid fracture result in the “terrible triad” of the elbow.



  • To gain insight into the size of a fracture fragment, a CT of the elbow may be beneficial.



  • Plain films of the wrist and/or forearm should be considered if clinically indicated (e.g., to evaluate for an Essex-Lopresti fracture).





Figure 2.14. Anterior (“sail sign”) and posterior fat pad signs in the setting of a radial head fracture.





Figure 2.15. A Mason type III comminuted fracture of the radial head.



ED Treatment



  • Elbow aspiration may decrease pain and increase ROM. (Figure 2.16)




    • There is no benefit of anesthetic injection with aspiration vs. aspiration alone for Mason type I fractures.36



  • Treatment in the ED should be guided by the Mason classification.




    • Type I: Treatment with a shoulder sling for up to three to four days with active ROM as soon as possible.37




      • These are treated nonoperatively.



      • Advise the patient to perform ROM to the point of pain.



      • Ice, acetaminophen, and/or oral opiates are reasonable for pain control.



    • Type II: These patients can be splinted with a posterior splint if neurovascularity is otherwise intact.




      • These patients should follow-up with an orthopedic surgeon within two to three days to be assessed for surgical evaluation.



      • While controversial, the literature currently trends to favoring a surgical repair of these injuries.38



      • However, if no mechanical block exists, Mason type II fractures may be treated conservatively.30



    • Type III: Orthopedic consultation is recommended for surgical intervention (open reduction internal fixation, or ORIF, resection, or resection with arthroplasty).39



    • Type IV: Reduction of the dislocation is essential.




      • Treatment of the fracture will then require the assistance of an orthopedic surgeon.



      • The timing of orthopedic consultation depends on the type of fracture (Mason type II vs. Mason type III).





Figure 2.16. Elbow aspiration/injection technique. Place the elbow flexed at approximately 90°. Identify the three key bony landmarks: LE = Lateral Epicondyle; RH = Radial Head; LO = Lateral Olecranon. After prepping the elbow in a sterile fashion, use an 18- or 20-gauge needle to enter the elbow joint through the recess in the center of the triangle created by the noted bony landmarks.



Disposition



  • Type I fractures can follow-up with a primary care or sports medicine provider in one to two weeks.




    • Be certain to counsel the patient to initiate ROM as soon as possible.



    • A subsequent referral to orthopedics can be made if a complication surfaces.



  • Type II fractures should have orthopedic surgery follow-up within two to three days of presenting to the emergency department.



  • Type III radial head fractures warrant orthopedic evaluation in the ED, especially in the setting of neurovascular compromise.



  • Type IV: If successfully reduced, with no other fractures or ligamentous injuries present, these patients may follow-up with orthopedics within one week.




    • The rules for follow-up of these injuries plus either type II or type III fractures is noted earlier.



Complications



  • Failure of the ROM to progress weekly should raise concern for an intra-articular mechanical block and warrant further investigation.



  • Minimal restriction of extension, supination, and pronation should be present at six weeks following a type I injury.



  • Patients may have increased cold sensitivity for one year.40



  • Partial ulnar nerve and/or posterior interosseous nerve injuries may occur.41



  • Long-term pain is infrequent.



Pediatric Considerations



  • Occult radial head fractures (e.g., type I fractures) in children may require longer splinting/casting to protect the fracture from displacement.



  • Consider imaging the contralateral side in patients whose growth plates are not fused.



Pearls and Pitfalls



  • The literature suggests that normal full elbow extension, lack of radial head/olecranon/medial epicondyle tenderness, and the absence of bruising excludes fracture in the adult elbow and eliminates the need for imaging.




    • This clinical decision rule does not apply to children.



  • Remember to palpate the wrist and the forearm to avoid missing concomitant injuries such as Essex–Lopresti fractures and Monteggia fractures.



  • Initiate ROM in these patients as soon as can be tolerated to prevent contractures/loss of motion.



  • When to intervene surgically for radial head fractures remains a controversial topic; a low threshold for contacting orthopedics is appropriate if there is concern.



Supracondylar Fractures



General Description



  • Supracondylar fractures are most common in the pediatric population, with a peak age of 5–6.42




    • Skeletally mature patients tend to suffer more elbow dislocations and intercondylar fractures.



  • Pediatric supracondylar fractures are described according to the Gartland classification.42 (Figure 2.17)




    • Type I: Nondisplaced and typically diagnosed based upon the presence of the posterior fat pad sign



    • Type II: Partially displaced but maintaining some degree of cortical continuity



    • Type III: Fully displaced with no continuity; high frequency of neurovascular injury








Figure 2.17. The Gartland classification of pediatric supracondylar fractures (Left) and a lateral radiograph depicting a type II injury with anterior and posterior fat pad signs (Right).



Mechanism



  • Supracondylar fractures typically occur from two different mechanisms: extension type (98%) and flexion type (2%).42



  • Extension-type fractures typically occur due to a FOOSH mechanism.




    • The distal fragment is displaced posteriorly.



  • Flexion-type fractures occur with a fall on a flexed elbow.




    • The distal fragment is displaced anteriorly.



Presentation



  • Patients present with complaints of elbow pain and/or swelling.



  • Extension-type injuries are often held in extension.



  • Flexion-type injuries are frequently held in flexion.



Physical Exam



  • There will be diffuse tenderness of the elbow and limited ROM.



  • A thorough neurovascular exam is essential.




    • Radial nerve and anterior interosseous nerve (median) injuries are most common.



    • Assess thumb extension (radial), finger abduction (ulnar), and the ability to make OK sign (anterior interosseous branch of median).



    • Two-point discrimination of more than 6 mm is abnormal.42



  • Assess for other ipsilateral fractures in the upper extremity.



  • Evaluate for evidence of compartment syndrome.



Essential Diagnostics



  • AP and lateral radiographs of the elbow should be obtained.




    • The posterior fat pad sign is much more reliable than the anterior fat pad sign.43



    • Obtain additional radiographs based upon concern for ipsilateral fractures of the upper extremity.



    • The anterior humeral line should pass through the middle third of the capitellum.43 (Figure 2.18)



  • Evaluate the lateral plain film for a figure–of-eight (or hourglass) sign. (Figure 2.19)




    • This shape is present in the distal humerus when a true lateral radiograph is secured.



    • Absence of this sign suggests an imperfect lateral view or a supracondylar fracture.





Figure 2.18. Lateral view of the elbow depicting an appropriate anterior humeral line.





Figure 2.19. Lateral view of the elbow displaying a proper figure-of-eight (hourglass) sign.



ED Treatment



  • Type I fractures that are closed and neurologically intact should be immobilized at 60–90° of flexion in a full arm posterior splint and neutral forearm rotation.42, 43




    • The patient needs outpatient follow-up with an orthopedic surgeon in twenty-four to forty-eight hours.



  • Type II fractures are largely managed with closed reduction and percutaneous pinning, although there is some variability in practice pattern.27, 4244




    • Splint the fracture at 20–40° of flexion.



    • Avoiding extremes of extension/flexion helps preserve blood flow.42



  • Type III fractures require operative fixation, usually with closed reduction and percutaneous pinning.27, 4244



  • All open fractures and fractures associated with neurovascular compromise require emergent orthopedic consultation.



Disposition



  • Closed, neurovascularly intact type I fractures can be splinted, with outpatient orthopedic follow-up in one to two days.27, 4244



  • Type II and type III fractures need emergent orthopedic consultation and admission for monitoring of neurovascular status.43



Return to Work/Sports



  • Due to the length of immobilization (three to six weeks), an additional four to eight weeks may be needed for ROM and strengthening exercises.43



  • The patient may return to work at any time, depending upon the ability to perform work duties with a splinted and/or weak upper extremity.



  • Physical therapy is recommended for those seeking accelerated return to work or sports, with a focus on ROM and strengthening.



Complications



  • Compartment syndrome should be considered in a patient refusing to open their hand, pain with passive extension, and/or severe forearm swelling and tenderness.



  • Anterior interosseous nerve (median) injury manifests as an inability to make “OK” sign (opposing distal phalanx of thumb and index finger).



  • Weakness with thumb extension and/or numbness at base of thumb may reflect a radial nerve injury.



  • Vascular injury (especially to the brachial artery) can lead to Volkmann’s contracture (forearm muscle wasting and weakness).



  • The most common long-term complication is elbow stiffness and loss of ROM.




    • A mild deficit of extension (10–15°) is common but does not typically affect function.45



Pediatric Considerations



  • The absence of a radial pulse is common in children, likely secondary to spasm.




    • Assess for other signs of ischemia/compartment syndrome is noted earlier.



    • Reduction of the fracture usually restores the pulse; reduction should not be delayed to obtain an angiographic study.



Pearls and Pitfalls



  • Supracondylar fractures may be mistaken for a posterior elbow dislocation on physical exam.



  • A supracondylar fracture may be confused with lateral/medial condyle fractures and transphyseal fractures.



  • When reducing the fracture avoid exaggerating the deformity to achieve anatomic alignment (e.g., applying additional valgus stress to a valgus deformity); this can result in damage to the brachial artery.



  • When the posterior fat pad sign is present in an adult, the differential diagnosis should also include a radial head fracture.



Monteggia Fractures



General Description



  • Monteggia fractures involve a fracture of the proximal third of the ulna with dislocation of the radial head.



  • The Bado classification system (type I–IV) describes the fracture-dislocation pattern based on the direction of ulnar angulation and direction of the radial head dislocation.46 (Figure 2.20)





Figure 2.20. The Bado classification system for Monteggia fractures.


Courtesy of Mike Cadogan.


Mechanism



  • The injury most commonly occurs due to a FOOSH mechanism.




    • The impact hyperpronates the forearm, resulting in the defining fracture/dislocation.



    • The fracture may also occur subsequent to a direct blow to the posterior ulna.



Presentation



  • Signs and presentation of a Monteggia fracture vary based upon the subtype of the lesion.



  • Patients present with pain, swelling, and a possible deformity.



  • Patients may complain of weakness with thumb extension and paresthesias in the radial nerve distribution due to injury to the posterior interosseous nerve.43



Physical Exam



  • The radial head may be palpable in the antecubital fossa.



  • The forearm may appear shortened.



  • A thorough neurovascular exam is essential, as the radial nerve is frequently injured with these fractures.




    • Assess the sensation over dorsum of the base of the thumb and thumb extension.



Essential Diagnostics



  • AP and lateral views are usually sufficient, but they must completely visualize the ulna, radius, elbow, and wrist.



  • McLaughlin’s line (or the radiocapitellar line) is helpful to assess for occult radial head dislocation.




    • This is a line drawn through radial shaft and head that should bisect the capitellum.47 (Figure 2.21)



    • This line should intersect the capitellum regardless of the degree of elbow flexion or extension.



    • If the ulna fracture is angulated, the apex will point in the same direction as the radial head dislocation.47





Figure 2.21. A lateral radiograph of the elbow depicting McLaughlin’s line properly bisecting the capitellum.



ED Treatment



  • Monteggia injuries have high potential for complications and merit consultation with an orthopedic surgeon in the ED.45, 47




    • Prompt reduction of the radial head is necessary to minimize risk of injury to the posterior interosseous nerve (radial nerve).



    • The radial head relocates as a result of reducing the ulna fracture.



  • The patient should be immobilized in a double sugar-tong splint. (Figure 2.22)




    • After open reduction and internal fixation (ORIF) of the ulna, the elbow is supported with a removable splint.



    • Active ROM is initiated within the first two weeks.48



    • Pediatric fractures treated with closed reduction are casted for approximately six weeks.45, 47, 48





Figure 2.22: A double sugar-tong splint.



Disposition



  • These patients warrant immediate consultation with an orthopedic surgeon in the ED.



Return to Work/Sports



  • Return to activity can be considered when ROM is near normal and strength is 80%.45




    • For patients treated with ORIF, ROM is initiated within the first two weeks.



    • Full return to work/recreational activity may take up to three to four months.49



    • Return to play is possible in four to six months.49



Complications



  • Radial nerve injuries are most common (posterior interosseous nerve).



  • Nonunion can occur.




    • The incidence for nonunion in forearm fractures is less than 2%.50



    • This rate is considerably higher for Monteggia lesions, particularly type IV injuries, as compared to other forearm fractures.50



  • Chronic radial head dislocations are more likely if the radial head dislocation is missed initially, resulting in limited pronation and supination.45



Pediatric Considerations



  • Orthopedic consultation in the ED is paramount.



  • Closed reduction is the treatment of choice for pediatric Monteggia fractures.45, 47, 48



  • Consider imaging the unaffected arm if a radial head dislocation is uncertain.



Pearls and Pitfalls



  • Concomitant distal forearm fractures may be missed.



  • The neuropraxia of the radial nerve often improves spontaneously and does not require surgical exploration.50



  • Prolonged immobilization increases risk of posttraumatic elbow stiffness.50



Little Leaguer’s Elbow/Osteochondritis Dissecans (OCD) Lesions



General Description



  • Elbow pain in the pediatric population (Little Leaguer’s elbow) is generally caused by repetitive valgus overload.



  • Little Leaguer’s elbow includes: medial epicondylar avulsion, medial humeral overgrowth (when chronic), ulnar neuritis, and OCD lesions of the capitellum. (Figure 2.23)




    • In the ED, the workup and treatment of the disease processes comprising Little Leaguer’s elbow is similar.



  • OCD lesions entail avascular necrosis of the subchondral bone and overlying articular cartilage.19




    • OCD is most common in adolescent males.19





Figure 2.23. An OCD lesion of the right capitellum in a high school pitcher.



Mechanism



  • The exact pathophysiology of OCD lesions is unknown.



  • Repetitive trauma or overuse, especially through throwing, is thought to lead to microfracture and compromised circulation of the subchondral bone.




    • This causes separation of the articular surface and formation of loose bodies.



Presentation



  • A skeletally immature patient with complaints that may include: 19, 45



  • The gradual onset of pain




    • Pain that is dull and aching



    • Loss of full elbow extension



    • Intermittent swelling



    • Decreased throwing effectiveness



    • Catching



    • Locking



    • Clicking



  • There is generally a history of repetitive trauma or sports-related activities.



Physical Exam



  • ROM of the elbow may be restricted, especially if a loose body is present.



  • The capitellum is the most common site of involvement, and a joint effusion may be present.19



Essential Diagnostics



  • Plain films of the elbow should include a minimum of three views (AP, lateral, and oblique). (Figure 2.24)




    • An osteochondral fragment in the joint or the lucency of the fracture may be visualized.



    • To delineate if there is a loose body present, contralateral elbow films may be obtained for comparison of the ossification centers.





Figure 2.24. AP radiographs of a patient with Little Leaguer’s elbow.



ED Treatment



  • Definitive management of OCD lesions is controversial and may be treated both operatively and nonoperatively.51



  • The first line of treatment is to cease the offending activity (especially throwing) and control pain.




    • Sufficient pain control may be obtained with NSAIDs.



  • Some recommend treatment by immobilization with a sling or cast.




    • However, rest and cessation of activities are the mainstays of treatment.



Disposition



  • Patients with OCD and/or Little Leaguer’s elbow may be safely discharged from the ED.



  • Outpatient orthopedic surgery or sports medicine follow-up is indicated.




    • Such a referral is especially important in cases with loose bodies, as they may require surgical excision.



    • Many of these injuries may be treated conservatively with relative rest, pain control, and a rehabilitation program.



  • The patient should not be cleared for return to sports from the ED.




    • Return to play without a brace may occur when there is resolution of the lesion by plain films or MRI.45



    • Return to play with a brace is appropriate when the patient has pain-free and full ROM.45



    • Time to radiographic healing is variable, ranging from six weeks to two years.51



Complications



  • In cases where surgical interventions have been performed, 10–20% of athletes fail to return to sports at the pre-injury level.45



  • Larger lesions are associated with increased risks of ongoing pain, stiffness, and arthritis.



Pediatric Considerations



  • OCD and Little Leaguer’s elbow are primarily disorders of the skeletally immature.



Pearls and Pitfalls



  • Plain films of the elbow (and possibly the contralateral elbow) are indicated to evaluate for fractures and/or loose bodies within the joint.



  • The first line of treatment is to cease the activity that causes pain (especially throwing).



  • Orthopedic surgery or sports medicine outpatient referral is indicated in all cases.



Ligamentous Injuries (UCL/RCL)



General Description



  • Valgus instability is caused by disruption of the medial collateral ligament complex (also referred to as the UCL complex or the “Tommy John” ligament).



  • The lateral ligament complex (also referred to as the RCL complex) prevents rotational instability between the distal humerus and the proximal radius and ulna.



  • Medial ligamentous instability is much more common than lateral instability.52



Mechanism



  • Valgus instability




    • Chronic instability commonly results from overhead throwing, particularly baseball.



    • It is due to repetitive microtrauma secondary to overload during the throwing process.



    • Dislocation of the elbow is the most likely etiology of acute instability.



    • The differential diagnosis includes medial epicondylitis, flexor/pronator injuries, ulnar neuropathy, and Little Leaguer’s elbow.



  • Rotational instability




    • Most commonly occurs secondary to trauma (e.g., an elbow dislocation) and involves an avulsion of the ligamentous origins from the lateral epicondyle.52



    • Other etiologies include iatrogenic injury during surgical intervention for lateral epicondylitis or operative interventions to the radial head.




      • It has also been described as a sequela of nonoperative treatment of lateral epicondylitis.53



Presentation



  • Valgus instability




    • Acute injury




      • In throwing athletes, a popping sensation may be reported in addition to the sudden onset of pain.



      • Direct trauma, including dislocation of the elbow, may cause this injury.



    • Chronic injury




      • Patients often describe vague elbow pain or localized medial elbow pain, generally gradual in onset.



      • It may be accompanied by ulnar nerve symptomatology.45



      • Throwing athletes report a decline in throwing velocity and accuracy, pain during the throwing motion, and/or pain following an episode of heavy throwing.54



  • Rotational instability




    • Common complaints include:




      • Pain



      • Locking



      • Snapping



      • Clicking



      • A feeling of instability



    • These complaints may be worse with activity.



    • Typically a history of trauma or elbow dislocation may be elicited.



    • If noted following a surgical intervention to the elbow an iatrogenic cause should be suspected.



Physical Exam



  • The elbow should be in 15–30° degrees of flexion for evaluation of ligamentous instability.




    • Only very subtle differences in laxity may be present, therefore requiring a very detailed examination.



  • Valgus instability




    • In acute injuries, an area of ecchymosis may be present over the medial elbow.



    • Tenderness to palpation may be present over the medial epicondyle.




      • Tenderness may subside following a period of rest and may not be present in chronic injuries.



    • Several of the special tests related to valgus instability are detailed in the “Focused Physical Examination” section earlier in this chapter and in Figure 2.7.45, 55




      • The valgus stress test may be performed in either the prone or seated position.




        • With the elbow in approximately 20° of extension, palpate the medial joint line.



        • Stabilize the distal humerus with the other hand and apply a valgus stress to the elbow.



        • A positive test results in pain or excessive laxity.



      • Modified milking maneuver.



      • Moving valgus stress test.



      • Examination of the contralateral elbow should be performed to aid in the differentiation between physiologic versus pathologic laxity.



  • Rotational instability




    • It is difficult to demonstrate instability, although provocative testing may reproduce the instability on clinical examination.52, 53



    • The lateral ligaments are tested with the varus stress test (Figure 2.7) and internal rotation of the arm.



    • The posterolateral rotary instability test may assess for rotational instability.




      • With the patient in the supine position place the affected arm overhead.



      • The elbow should be in full extension and the forearm supinated.



      • Apply a valgus force with axial compression as the elbow is slowly flexed.




        • This may cause dislocation of the radiocapitellar joint.



        • Pronation and continued flexion reduces the joint.



        • Apprehension is also considered a positive test.



Essential Diagnostics



  • Valgus instability




    • Radiographs including a minimum of three views of the elbow (AP, lateral, and oblique views) should be obtained.



    • Additionally, valgus stress radiographs may be obtained.




      • Stress radiographs should be taken of both elbows for comparison.



      • There are no cutoff values for abnormal stress radiographs, although increased opening of 0.5 mm is indicative of injury.55



      • The most common abnormal findings are olecranon osteophytes and calcifications within the UCL.54



    • Additional studies may include MRI, CT arthrogram, and/or ultrasound. (Figure 2.25)




      • Imaging aside from radiographs is generally not indicated in the ED.



  • Rotational instability




    • Plain and stress radiographs are the most useful diagnostic tools aside from the physical examination.




      • Subtle abnormalities in chronic instability may be present, most notably a defect in the posterolateral margin of the capitellum.53








Figure 2.25. Contrast-enhanced MRI imaging of a high school pitcher with a UCL tear.



ED Treatment



  • Valgus instability




    • Acute injuries associated with elbow dislocation necessitate reduction of the elbow, splinting, and careful evaluation for neurovascular compromise.



    • If neurological or vascular compromise is noted, emergent consultation with orthopedic surgery and/or vascular surgery is indicated.



    • A trial of supportive, nonsurgical treatment is appropriate in isolated UCL injuries.54, 55




      • Cease throwing activities and activities that provoke pain.



      • Provide pain control with NSAIDs.



  • Rotational instability




    • Halt activities that provoke the symptoms.



    • Provide pain control as needed.



Disposition



  • Valgus instability




    • In the setting of an acute injury with an associated elbow dislocation, disposition is dependent on neurovascular status and the availability of close follow-up.



    • Isolated acute and chronic injuries may be safely discharged from the ED.




      • Follow-up with an orthopedic surgeon or sports medicine provider within one week for reassessment and initiation of a rehabilitation program is advised.



      • Athletes should not be cleared for return to play from the ED.



      • The following patients are surgical candidates:55




        • Throwing athletes with a complete UCL tear



        • Failed rehabilitation of partial tears



        • Symptomatic, non-throwing athletes following a minimum of three months of rehabilitation



  • Rotational instability




    • These patients may be safely discharged from the ED.



    • There are no absolute indications for surgical repair.53



    • Follow-up with an orthopedic surgeon or sports medicine provider in approximately one week.



Complications



  • While rare, an associated medial epicondyle fracture may require surgical intervention.54



  • Following a surgical intervention, transient neuropraxia of the ulnar nerve may be present.54



Pediatric Considerations



  • The pediatric considerations for similar elbow pain are discussed in detail in “Little Leaguer’s Elbow/OCD Lesions” earlier in this chapter.



Pearls and Pitfalls



  • In acute injuries associated with an elbow dislocation, the neurovascular status of the extremity should be reassessed frequently.



  • Plain radiographs, including stress views, are the most useful diagnostic tool aside from the physical examination.



  • For chronic injuries, activity modification, especially ceasing activities that provoke the symptoms, is the first-line treatment.



Biceps Tendon Ruptures



General Description



  • The distal biceps inserts at the bicipital tuberosity of the radius.




    • The brachial artery and median nerve sit just medial to the biceps insertion.



  • Primarily, the biceps serves as a forearm supinator.




    • Its secondary role is as an elbow flexor.



  • These ruptures represent only 10% of all biceps ruptures (90% are proximal).56



  • Distal biceps ruptures are more prevalent in males between the ages of 40 and 60.57



  • The dominant arm is affected 80% of the time.58



  • A classification for the extent of injury exists (Ramsey Classification), but it is not practical for use in the ED.59




    • A component of the classification, chronicity of injury, is relevant.



    • Acute injuries are those that occur within four weeks of presentation.



Mechanism



  • The most common mechanism of injury involves an eccentric force (lengthening contraction under tension) with the elbow flexed at 90°.60



  • Older patients may have a more innocuous mechanism secondary to an underlying degenerative distal biceps tendon.



Presentation



  • Most patients will describe an acute incident associated with a “snap” sound or a tearing sensation.



  • A significant decrease in strength with forearm supination and elbow flexion will often be detailed.




    • However, for chronic injuries (longer than four weeks), flexion strength may increase significantly, although likely not back to baseline.61



    • Forearm supination weakness will remain prominent.



Physical Exam



  • Important visual signs at the flexion crease of the elbow associated with a distal biceps rupture include:




    • Swelling



    • Loss of the fullness of the anterior elbow



    • Ecchymosis



  • A palpable defect is usually appreciated.




    • The hook test can assist in assessing a potential distal biceps defect. (Figure 2.5)




      • Continuity of the tendon on palpation may suggest a partial distal biceps tear.



  • Prominence at the mid- or proximal humerus is often seen, known as the “reverse Popeye sign.” (Figure 2.26A)




    • Active biceps flexion may produce retraction of the muscle belly proximally.



    • This can also be seen with proximal biceps tendon ruptures (referred to as a “Popeye sign” with the prominent biceps muscle typically located more distally towards the elbow. Please see further discussion in the Shoulder chapter).



  • Observe for lack of and/or weakness with supination and/or flexion at the elbow.



  • Perform the biceps squeeze test. (Figure2.26B)




    • Hold the elbow in 60–80° of flexion with the wrist slightly pronated.



    • With one arm stabilizing the elbow, the other hand should squeeze across the biceps brachii.



    • A positive test is a failure to observe supination.



    • This test has a sensitivity of 96%.62








Figure 2.26A and B. A, A positive “reverse Popeye sign” due to a distal biceps tendon rupture. Courtesy of Francis Lam. The biceps squeeze test.



Essential Diagnostics



  • A distal biceps rupture is a clinical diagnosis; no imaging is essential in the ED to make this diagnosis.



  • Plain films of the elbow (AP and lateral) should be considered to rule out an avulsion fracture. (Figure 2.27)



  • Ultrasound may be beneficial, but MRI is the imaging modality of choice to confirm the diagnosis.




    • MRI has a sensitivity of 92% with a specificity of 85% for these injuries.13



    • Neither ultrasound nor MRI is indicated in the ED.





Figure 2.27. “Reverse popeye sign” as seen on plain films.



ED Treatment



  • Acute management in the ED revolves around pain control.



  • ROM, without resistance, is encouraged to prevent a loss of motion.



  • No splinting or immobilization is indicated.




    • A shoulder sling may be used for comfort.



  • Caution patients against significant lifting or repetitive supination/pronation activities.



Disposition



  • Follow-up with an orthopedic surgeon is recommended within two to three days.




    • Surgical outcomes are optimal if the repair occurs within two weeks, although up to four weeks is acceptable.63



    • The goal with early surgery is to prevent scarring of the tendon.



  • Patients may elect for nonoperative treatment.




    • This is more appropriate in the elderly, sedentary, or otherwise poor surgical candidates.



  • Studies have shown that patients undergoing an operative repair may regain up to 97% flexion strength and 95% supination strength.64



  • The typical postoperative recovery period for full return to work or sport following surgery is six to seven months.45



Complications



  • Nonoperative treatment may result in 30% less flexion strength, 40% less supination strength, and up to 86% less supination endurance.64, 65



  • Depending upon where the tendon scars, there may be decreased flexion in patients who refrain from operative repair.



  • There are some complications associated with surgery (radial nerve injury, loss of rotation, heterotopic ossification, etc.).




    • 3–4% of patients will have persistent nerve lesions.66



  • Complications tend to occur more often in chronic distal biceps ruptures (lasting more than four weeks).67



  • Re-rupture is an uncommon occurrence, but has been reported (2%).68



Pediatric Considerations



  • This is an extremely rare condition in the pediatric population; no special considerations exist.



Pearls and Pitfalls



  • Pay particular attention to a patient’s supination strength at the elbow, as that may prove more insightful than flexion strength.



  • Use the hook and biceps squeeze tests to better delineate the patient’s pathology.



  • Refrain from advanced imaging in the ED.



  • Ensure prompt orthopedic follow-up to avoid the sequelae of decreased ROM, strength, and endurance at the elbow.



Distal Triceps Tendon Ruptures



General Description



  • The distal triceps inserts at the olecranon, forming both deep and superficial attachments.




    • The radial nerve innervates the triceps muscle.



  • It is the only major elbow extender.




    • Its secondary role is as an elbow flexor.



  • These injuries were once thought to be extremely rare, but their prevalence has been increasing.




    • The injury is twice as likely to occur in men.69



    • There is no clear predilection to dominant or nondominant sides.70



Mechanism



  • Most frequently, distal triceps tears are the result of a fall on an outstretched hand with a concomitant eccentric contraction of the triceps upon impact.71



  • Another possible mechanism of injury involves a direct below to the elbow.




    • An associated avulsion fracture of the olecranon may also be present.



Presentation



  • A specific inciting event or traumatic injury is often noted.



  • A tearing sensation is frequently reported.



  • Inquiring about a loss of elbow extension might be beneficial in making the diagnosis.



  • Particular activities have a higher reported risk of causing distal triceps ruptures.




    • Weightlifting, football, baseball pitching, and javelin throwing are associated with these injuries.7275



  • There are other pre-disposing risk factors that warrant consideration.72, 7679




    • Hyperparathyroidism



    • Osteogenesis imperfecta



    • Marfan syndrome



    • Systemic lupus erythematous



    • Steroid use (local and systemic; anabolic or otherwise)



Physical Exam



  • A palpable depression may be appreciated just proximal to the olecranon.




    • This may be subtle in the setting of acute swelling or an individual with significant muscle mass.



  • Ecchymosis might be present, but it may also take several days to surface.



  • The key to the diagnosis is assessing the ability to extend the elbow and the associated strength.




    • Start by assessing the patient’s ability to extend the elbow against gravity.



    • Marked weakness suggests a complete triceps tear.



    • Utilize the contralateral extremity for comparison.



  • The Thompson triceps test also has some utility. (Figure 2.28)




    • Hold the arm in flexion against gravity.



    • Compress the triceps.



    • A positive test will result in no extension of the elbow with compression.



  • Other physical exam findings associated with a distal triceps rupture include:




    • Cubital tunnel syndrome: irritation, entrapment, or compression of the ulnar nerve.



    • Snapping elbow: may be due to the ulnar nerve or the medial head of the triceps snapping across the medial epicondyle.


Sep 1, 2020 | Posted by in SPORT MEDICINE | Comments Off on Chapter 2 – Elbow
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