Overview of Pathologies
The key to diagnosing elbow injuries involves performing a thorough history and physical examination of the elbow. Additionally, to rule out referred pain, the surrounding areas such as the cervical spine, shoulder, wrist, and hand should also be examined. This chapter discusses the elements of a complete elbow history and physical examination, which include inspection, palpation, range of motion, strength, neurologic assessment, joint stability testing, and various provocative maneuvers to help identify and characterize different disorders around the athlete’s elbow.
Because a wide variety of pathologies pertain to the elbow, a logical approach is necessary to accurately diagnose the disorders. A helpful strategy is to divide the elbow into four anatomic regions—anterior, posterior, medial, and lateral—which enables the examiner to narrow the range of the differential diagnosis. In addition, knowing the patient’s athletic history can help focus the decision making regarding treatment.
Pathologic conditions that are present around the lateral aspect of the elbow include lateral epicondylitis, radial nerve compression neuropathies, osteochondritis dissecans (OCD) of the capitellum, posterolateral rotatory instability, and radiocapitellar arthritis. Symptoms arising from the medial aspect of the elbow include medial epicondylitis, cubital tunnel syndrome, flexor-pronator strain, and medial (ulnar) collateral ligament injury. Conditions causing symptoms at the posterior elbow include olecranon bursitis, olecranon stress fracture, posteromedial impingement syndrome such as a valgus extension overload seen in overhead throwing athletes, triceps tendinopathy, or a triceps rupture. The differential diagnoses for anterior elbow pain include medial nerve compression neuropathies, distal biceps tendinopathy, partial or complete distal biceps tendon ruptures, and an anterior capsular strain from a hyperextension injury.
Athletes typically present with pain, mechanical symptoms, and a compromised ability to play. The pain may be exacerbated by activity and relieved with rest, or it can be persistent with daily routines. It is therefore helpful to localize the athlete’s symptoms into one of the four anatomic regions previously described.
Symptoms involving the lateral elbow are typically related to lateral epicondylitis, PIN compression neuropathy, OCD lesion of the capitellum, posterolateral rotatory instability, and/or radiocapitellar arthritis. Lateral epicondylitis is often associated 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. In patients with OCD lesions, many 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. In these cases, the patient will often report exacerbation of pain with the extremes of elbow motion.
Radial nerve compression syndromes include the PIN compression neuropathies of PIN syndrome 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, with prolonged compression as seen in the “Saturday night palsy” or Parsonage-Turner syndrome. RTS is similarly uncommon. It is characterized by pain that is exacerbated with activity and commonly located in the extensor mobile wad and proximal lateral forearm. Athletes who throw 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.
Complaints localized to the medial aspect of the elbow may result from medial epicondylitis, cubital tunnel syndrome, 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 may 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 of the associated fibers. Medial epicondylitis has been associated with ulnar nerve symptoms in as many as 40% 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 could relate to medial collateral ligament disruption. 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.
Athletes may present with anterior elbow pain for a number of reasons, including medial nerve compression neuropathies such as pronator or anterior interosseous nerve (AIN) syndrome, distal biceps tendinosis, partial or complete distal biceps rupture, 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 weightlifting, rugby, or football. Soliciting a history of the use of performance-enhancing drugs is helpful. 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 most commonly results from compression of the median nerve as it passes between the two heads of the pronator teres. This rare condition may also be associated with a humeral supracondylar process with compression of the median nerve by a traversing fibrous band called the ligament of Struthers . The presenting symptoms are aching pain in the proximal, volar forearm. Paresthesias radiating into the radial side of the hand can be distinguished from carpal tunnel syndrome by its involvement of the palmar cutaneous branch. 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.
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. 62-1 ). 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.When taking a history, especially in throwing athletes, 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.
For a diagnostic test to be clinically useful, it must be easily performed, reliable, reproducible, and have high sensitivity and specificity. In evaluating elbow injuries, a combination of inspection, palpation, range of motion, strength, stability, neurologic assessment, and other provocative maneuvers will assist in the development of a working diagnosis. A comprehensive evaluation is recommended for and expected of the novice observer, whereas a more focused physical examination may be performed by experienced practitioners who incorporate key clues from the history more readily.
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 in athletes whose sport involves throwing.
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). 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 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.
The next part of the physical examination, palpation, involves assessing asymptomatic areas first while progressively moving toward the symptomatic area. It is important for the physician to understand the qualitative aspect of this portion of the examination and to use maneuvers while palpating to understand what exacerbates or relieves symptoms.
Beginning with the lateral elbow, the bony prominences should be palpated, which include the lateral epicondyle, radial head, and olecranon process. The radiocapitellar joint line should also be palpated for tenderness. Based on the history, point tenderness of the lateral epicondyle in the setting of trauma could be indicative of lateral collateral ligament disruption.
Tenderness due to lateral epicondylitis may be palpated just anterior and distal to the lateral epicondyle where the extensor carpi radialis brevis originates and may extend distally from the lateral epicondyle for several centimeters along the common extensor origin. Pain associated with lateral epicondylitis is generally worsened with elbow extension with resisted wrist extension and a clenched fist.
Pain with pressure directly over the radiocapitellar joint, especially when combined with active pronosupination of the forearm with axial loading (e.g., active radiocapitellar compression test), is indicative of radiocapitellar pathology. In the middle-aged adult patient, point tenderness at the posterolateral elbow points more to radiocapitellar arthritis, although it may be more indicative of an OCD lesion in adolescent patients.
Next, the presence of an effusion can be palpated over the anconeus, or “soft spot.” As for intraarticular injections, the soft spot can be found at the center of a triange drawn between the olecranon, lateral epicondyle, and radial head. An effusion in that area can present with fullness over the soft spot and should raise suspicion for an underlying injury.
Local, vague tenderness in the region of the proximal lateral forearm, especially along the course of the PIN, is more consistent with the diagnosis of RTS versus PIN syndrome and is explained later in this chapter.
Palpation of the medial elbow begins with the bony prominence of the medial epicondyle. The tenderness associated with medial epicondylitis is often located on the anteromedial facet of the medial epicondyle where the pronator teres and flexor carpi radialis originate. The involvement of the pronator origin can be isolated by palpating the proximal third of the medial epicondyle while resisting forearm pronation. The flexor carpi ulnaris origin is isolated by palpating the distal third of the medial epicondyle with resisted flexion and ulnar deviation. The medial (ulnar) collateral ligament is best palpated when the elbow is flexed to 50 to 70 degrees, which anteriorly translates the medial muscles. Tenderness associated with medial collateral ligament tear will be along the course of the ligament either at the origin on the medial epicondyle or at the insertion on the sublime tubercle of the proximal ulna. The ulnar nerve can be palpated directly beneath the medial epicondyle (described later in this chapter).
Palpation of the anterior elbow begins in the antecubital fossa, where multiple soft tissue structures can be palpated: the distal biceps tendon, brachioradialis, lacertus fibrosus, brachialis, and pronator teres. Distal biceps tendon pathology is the most common source of anterior elbow pain in the athlete, and the tendon is readily palpable in the antecubital fossa with the elbow supinated. The hook test or biceps squeeze test can be performed to assist in the diagnosis of distal biceps tendon rupture and are detailed later in this chapter. Tenderness along the distal extent of the tendon with resisted supination in the face of an intact tendon suggests pain from distal biceps tendinosis.
Medial nerve compression neuropathies, specifically pronator syndrome, can have anterior elbow and forearm pain with palpation. Deep palpation or Tinel test of the median nerve in the antecubital fossa can elicit pain in the proximal forearm and elbow, but median nerve symptoms would also be expected distally in the hand (discussed later in this chapter).
Palpation of the posterior elbow involves palpating the triceps tendon and the olecranon process. When the elbow is flexed to approximately 30 degrees, the triceps is relaxed, allowing for easier access to the medial and lateral gutters of the posterior compartment. Fullness in these regions is consistent with an intraarticular inflammatory process. Tenderness on the medial or lateral aspect of the trochlea can be seen in association with spurs on the posterior aspect of the distal humerus. Pain with terminal extension can be seen with spurs on the tip of the olecranon process. Boxers can fracture the tip of the olecranon process, particularly in their nondominant elbow, during a jab. Tenderness from this type of fracture may be elicited at the apex of the olecranon process with the elbow slightly flexed.
Pain elicited along the posteromedial aspect of the olecranon in overhead throwing athletes should immediately warrant a focused exam for posteromedial impingement syndrome. It is also important to carefully evaluate the integrity of the medial collateral ligament because there is an association between medial collateral ligament injury and posteromedial impingement syndrome. The extension impingement and arm bar test are sensitive physical exam maneuvers that can be used (discussed later in this chapter).
A palpable defect in the triceps just proximal to the tip of the olecranon is indicative of triceps tendon rupture. Complete ruptures typically involve the posterior superficial portion of the tendon, which is made up of the long and lateral heads of the triceps. This leaves the deep anterior, portion of the tendon, which is composed of the medial head of the triceps, intact.
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 degrees 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.
The neurologic examination includes an assessment of skin appearance and texture, muscle bulk, strength, sensation, reflexes, and provocative maneuvers for nerve compression. Loss of skin texture and abnormal sweat patterns on the finger pads are signs of significant sensory denervation. Similarly, loss of muscle bulk follows motor denervation or limb disuse.
Elbow flexion strength is best tested with the elbow flexed 90 degrees and the forearm in neutral rotation. The contribution of flexion strength from the brachialis is disproportionate compared with the biceps. Triceps strength is demonstrated by extension of the elbow with and without the aid of gravity and then against increasing resistance. To eliminate the aid of gravity, the patient should be asked to extend the elbow while in the supine position with the arm forward flexed to 90 degrees and the elbow in 90 degrees of flexion ( Fig. 62-2 ). Triceps strength is assessed with resisted elbow extension starting with the elbow in 100 degrees of flexion. Pronation and supination are best evaluated with the elbow at 90 degrees of flexion and the forearm starting in neutral rotation. Although not an absolute rule, the dominant extremity has been shown to be approximately 10% stronger than the nondominant extremity.