Elbow Diagnosis and Decision-Making

Lateral Elbow

Symptoms involving the lateral elbow are typically related to lateral epicondylitis, radial nerve compression neuropathies, OCD lesion of the capitellum, posterolateral rotatory instability, and/or radiocapitellar arthritis.

Lateral epicondylitis, often known as “tennis elbow,” is caused by tendinosis and inflammation at the origin of the extensor carpi radialis brevis (ECRB). Patients often present with a “burning” pain that radiates from the lateral epicondyle distally along the extensor muscles of the forearm. This pain is intensified by a combination of elbow extension, resisted wrist extension, and a tight grip. Eccentric loading during these combined maneuvers, as seen when hitting a backhand late in tennis or catching a golf swing “fat” (i.e., striking the ground before the ball), may trigger the symptoms associated with lateral epicondylitis.

Sharp pain in the lateral aspect of the elbow associated with locking or catching can result from loose bodies in the radiocapitellar joint or an OCD lesion of the capitellum. Patients at risk for OCD lesions include young overhead throwers and gymnasts. Young overhead throwers develop OCD lesions as an overuse injury from increased compression and shear forces during the late cocking phase of throwing across the radiocapitellar articulation. The radiocapitellar joint also experiences 60% of axial load placed across the elbow, which can cause OCD lesions in gymnasts after repetitive loading. These patients often report an insidious onset of symptoms with limitation of elbow motion, particularly elbow extension. Mechanical symptoms involving the elbow are often found in patients with radiocapitellar arthritis, with symptoms most severe at extremes of elbow motion.

Radial nerve compression syndromes include compression neuropathies involving the posterior interosseous nerve (PIN) and radial tunnel syndrome (RTS). PIN syndrome is characterized by a pure motor loss of extension of the thumb and fingers. This syndrome is exceptionally uncommon in athletes in the absence of a mass in the region of the radial neck, prolonged compression as seen in the “Saturday night palsy,” or Parsonage-Turner syndrome. RTS is also quite uncommon. It is characterized by pain that is exacerbated with activity and commonly located in the extensor mobile wad and proximal lateral forearm. Throwing athletes may experience this pain at the end of follow through. Symptoms of posterolateral rotatory instability usually follow a history of prior elbow dislocation in an athlete. Complaints include lateral-sided elbow pain, snapping, locking, subjective instability, and recurrent elbow dislocation.

Medial Elbow

Complaints localized to the medial aspect of the elbow may result from cubital tunnel syndrome, medial epicondylitis, and medial (ulnar) collateral ligament injury.

Paresthesias radiating along the medial portion of the forearm to the ring and small finger are typical of cubital tunnel syndrome. Patients often complain of nocturnal symptoms or symptoms exacerbated by prolonged elbow flexion. Popping or snapping along the medial aspect of the elbow may result from a subluxating ulnar nerve or movement of the medial head of the triceps after ulnar nerve transposition.

Medial epicondylitis, also known as “golfer's elbow,” is also found in racquet sports and baseball. It is associated with a history of repetitive forceful forearm pronation or wrist flexion. In golfers, it typically involves the dominant arm. A single “fat” shot leading to eccentric loading of the flexor-pronator mass or repetitive loading of the elbow can lead to disruption of the flexor pronator origin, with ischemia and development of angiofibroblastic hyperplasia. Medial epicondylitis has been associated with ulnar nerve symptoms in up to 60% of cases.

Athletes who throw and sustain an isolated acute medial collateral ligament injury will frequently describe a pop, sharp pain, and the inability to continue pitching or throwing. Insidious medial elbow pain with associated loss of velocity and control in throwing athletes are signs of chronic medial collateral ligament injury. Medial elbow discomfort in the setting of acute elbow trauma from higher-energy mechanisms can relate to disruption of the medial collateral ligament. These patients typically have associated injuries, such as radial head fracture, capitellum fracture, or dislocation. Throwing athletes with flexor-pronator strains have a history similar to that of medial collateral ligament injury.

Anterior Elbow

Athletes may present with anterior elbow pain for a number of reasons, including partial or complete distal biceps rupture, distal biceps tendinosis, median nerve compression neuropathies such as pronator or anterior interosseous nerve (AIN) syndrome, and anterior capsular strains.

Distal biceps tendon ruptures are most often reported with a traumatic event involving an unexpected extension force applied to the flexed arm that can occur in weight lifting, rugby, or football. A history of anabolic steroid use is helpful, as this is a significant risk factor for tendon ruptures, most notably in the upper extremity. A distal biceps rupture is usually associated with a pop followed by pain and weakness in the upper extremity. The intense pain recedes quickly, as does the initial weakness of elbow flexion. Patients are usually left with weakness in forearm supination and, rarely, cramping in the arm. Distal biceps tendinosis is associated with anterior elbow pain that is more pronounced with repetitive forearm supination and resisted elbow flexion.

Pronator syndrome is a rare condition that results most commonly from compression of the median nerve as it passes between the two heads of the pronator teres. There are other locations of potential compression; these are described later in the chapter. Patients present with aching pain in the proximal volar forearm and paresthesias radiating into the radial side of the hand, namely the thumb to the radial border of the ring finger. Symptoms may worsen with repetitive forearm rotation as well. AIN syndrome is a pure motor palsy with symptoms found distally in the hand. However, patients may have a vague achy discomfort in the anterior elbow associated with median nerve compression at that level.

Posterior Elbow

Athletes may experience posterior elbow pain due to olecranon bursitis, a stress fracture, posteromedial impingement syndrome (e.g., valgus extension overload syndrome), triceps tendinosis, and triceps tendon rupture. Olecranon bursitis typically occurs after either a single traumatic episode or with repetitive pressure or a shearing force on the apex of the elbow. Olecranon stress fractures are seen most often in gymnasts, athletes who throw, and weight lifters ( Fig. 58.1 ). These athletes present with reports of posterior elbow pain, loss of terminal extension, and in some cases elbow clicking or catching.

Posteromedial impingement syndrome (e.g., valgus extension overload syndrome) is nearly exclusive to throwing athletes who report pain at the posteromedial aspect of the elbow during the follow-through phase while reaching terminal elbow extension. This is usually secondary to posterior olecranon osteophytes impinging in the fossa at the terminal extension phase.

Patients who have triceps tendinopathy have pain with elbow extension, especially against resistance. An athlete with a distal triceps tendon rupture will often recall a specific traumatic event during resisted elbow extension, followed by intense pain and significant weakness. Rupture may occur with minimal trauma in patients who use anabolic steroids.

Overall, elbow injuries are most commonly found in throwing athletes. The American Academy of Orthopaedic Surgeons (AAOS) reports that 50% to 75% of adolescent baseball players report episodes of elbow pain during play. In taking a history, especially from a throwing athlete, it is important to determine when symptoms occur in the throwing phase. Medial-sided symptoms usually occur during the late acceleration and cocking phase compared with posterior elbow symptoms, which occur during the deceleration and follow-through phase.

Inspection

Inspection is the initial step of the physical examination of the elbow and, if possible, should include a comparison of the injured side with the uninjured side. During inspection, the physician should assess the skin and soft tissue envelope for signs of acute injury such as ecchymosis, swelling, deformity, abnormal muscle contour, and chronic changes such as muscle hypertrophy or atrophy.

During inspection, a measurement of the carrying angle is useful, especially for throwing athletes. The carrying angle of the elbow is the angle between the axis of the humerus and the axis of the forearm measured with the elbow extended and the forearm maximally supinated (the anatomic position) in the coronal plane. Typically, the angle is 7 to 13 degrees of valgus. Paraskevas et al. found that the mean carrying angle of the general population is almost 13 degrees, with men averaging 2 degrees less and women 2 degrees more. The increased angle in women has been attributed to increased joint laxity in women compared with men. Variations in the carrying angle can be due to previous trauma, injury, developmental abnormality, or adaptive changes to repetitive stress. In professional throwers, it is common to see carrying angles greater than 15 degrees. Fick submitted the “muscle theory,” which accounts for the greater carrying angle in athletes who throw. This theory hypothesizes that the increased strength of the brachioradialis and extensor carpi radialis longus in athletes who throw will cause a greater radial deviation in extension and thus a greater carrying angle. It has also been hypothesized that an increased amount of stress on the elbow joint in athletes who throw may lead to increased laxity of the joint, which also contributes to a greater carrying angle.

When evaluating patients for atrophy or hypertrophy of muscles of the arm or forearm, girth measurements compared with the contralateral side are useful when appropriate. Hypertrophy of the forearm musculature is often present in the dominant extremity of many types of athletes. Atrophy of the arm and forearm muscle may also indicate disuse because of chronic discomfort or an underlying neurologic disorder.

Palpation

It is important to start with palpation of asymptomatic areas first while progressively moving toward the symptomatic area. Additionally, the physician must understand the qualitative aspect of this portion of the examination and use maneuvers while palpating to understand what exacerbates or relieves symptoms.

Motion

The normal arc of flexion-extension ranges from 0 to 140 degrees, ±10 degrees. Loss of terminal extension is common in athletes with elbow pathology. Greater variation is found in the pronation-supination arc than in the flexion-extension arc; however, approximately 75 degrees of pronation and 85 degrees of supination are considered to be within normal ranges. The arc of motion required for daily activities ranges from 30 to 130 degrees of flexion-extension and 50 degrees of pronosupination in each direction. Depending on the sport, loss of terminal extension may create a significant impairment. It is important to note at which point in the arc of motion that pain or mechanical symptoms occur because this information may provide clues to the diagnosis.