Biceps tendinopathy and tendon rupture

INTRODUCTION — Shoulder pain is a common presenting complaint to primary care offices and sports medicine clinics. The basic workup for shoulder pain should include assessment of the biceps tendon, which has been considered a common cause of shoulder pain since the 1930s [1,2].

Biceps tendon injuries include a spectrum of disorders ranging from mild tendinopathy to complete tendon rupture. Rupture occurs most frequently at the long head of the proximal tendon, but may occur in the distal tendon. Coexistent injuries at the biceps tendon origin and superior glenoid labrum constitute a variety of disorders known as SLAP (superior labrum, anterior to posterior) lesions [3]. SLAP lesions are reviewed separately. (See "Superior labrum anterior to posterior (SLAP) tears".)

This topic review will discuss the presentation and management of biceps tendinopathy (primarily of the proximal long head of the biceps tendon) and biceps tendon rupture, both proximal and distal. The general evaluation of shoulder complaints in adults and other discrete causes of shoulder pain and dysfunction are reviewed separately. (See "Evaluation of the adult with shoulder complaints" and "Physical examination of the shoulder" and "Rotator cuff tendinopathy" and "Presentation and diagnosis of rotator cuff tears" and "Overview of upper extremity peripheral nerve syndromes", section on 'Proximal neuropathies' and "Clinical manifestations and diagnosis of osteoarthritis", section on 'Shoulder'.)

EPIDEMIOLOGY AND RISK FACTORS — Data describing the incidence of biceps tendon injury by sport or occupation is scant and should be interpreted cautiously. Such injuries appear to occur more often among those who engage in frequent pulling, lifting, reaching, or throwing for work or recreation. Two clinical series describe biceps tendon ruptures in rock climbers and weight lifters [4,5].

Degenerative tendinosis and biceps tendon rupture are usually seen in older patients, while isolated tendonitis usually presents in the young or middle aged [1]. According to a single-center study from the United Kingdom, among older patients (seventh decade of life) biceps tendon ruptures occurred at a rate of 0.53/100,000 over five years, with a male to female ratio of 3:1 [6]. This study did not distinguish among proximal and distal biceps tendon injuries. Based on clinical experience, proximal biceps tendon injuries are far more common.

The rate of distal biceps tendon rupture in the United States is 2.55 per 100,000 patient-years, according to a retrospective national database study [7]. The median age at time of rupture was 46, males comprised 96 percent of cases, and rupture risk was associated with smoking and increased body mass index. Smoking is associated with compromised vascularization of the biceps tendon as demonstrated by histological examination [8]. Biceps tendon rupture risk is modestly increased with concomitant fluroquinolone or glucocorticoid use. General inflammation as evidenced by an elevated C-reactive protein is associated with biceps tendon tear [9]. (See "Fluoroquinolones", section on 'Musculoskeletal'.)

CLINICAL ANATOMY — The biceps muscle is made up of a long and short head, each of which has a unique proximal tendon origin on the scapula, but which share a distal attachment on the bicipital (radial) tuberosity (figure 1). Shoulder anatomy is reviewed in detail separately. (See "Evaluation of the adult with shoulder complaints", section on 'Anatomy and biomechanics'.)

The long head biceps tendon (LHBT) is divided into three clinically relevant zones, each with potentially distinct pathology [10]. These zones include:

●Inside – Includes superior labrum and biceps anchor. The biceps anchor is the proximal attachment site for the LHBT. The tendon anchor site can be the bony supraglenoid tubercle or the cartilaginous superior labrum [10].

●Junction – Includes intra-articular portion of LHBT and pulley. The pulley is a capsulo-ligamentous complex that stabilizes the LHBT at the proximal portion of the bicipital groove.

●Tunnel – Includes extra-articular portion of LHBT

The LHBT originates intra-articularly at the superior glenoid tubercle, where it contributes to the formation of the glenoid labrum. The precise origin of the LHBT exhibits considerable anatomic variation [10]. It primarily extends from the glenoid rim as a rope-like structure coursing over the head of the humerus, and then into the intertubercular groove of the humerus, where it is reinforced by a covering of thick fascia. The LHBT then extends distally to the musculotendinous junction where it merges into the long head of the biceps muscle.  

The short head biceps tendon, together with the coracobrachialis muscle, originates at the coracoid process, medial to the long head tendon, and to the glenohumeral joint. Just distal from its origin, the short head separates from the coracobrachialis to form a distinct short head biceps tendon. As the proximal short head biceps tendon travels medial to the shoulder joint, and not below the acromion, it is far less susceptible to injury or tendinosis than the long head biceps tendon.

The two heads of the biceps muscle merge at the distal arm, ultimately forming a tendon that inserts onto the radial tuberosity. A bicipital aponeurosis provides an additional distal attachment by merging with the fascia over the forearm flexors and inserting onto the ulna.

The major functions of the biceps brachii muscle are supination of the forearm and flexion of the elbow. The proximal long head of the biceps may contribute to stabilizing the humeral head anteriorly, but this remains a subject of debate [11]. The biceps is innervated by the musculocutaneous nerve (figure 2) [12].

MECHANISM OF INJURY — Some experts believe that proximal biceps tendon injury is not due to a unique mechanism but rather results from general shoulder pathology, such as impingement or instability. Shoulder impingement is discussed in detail separately. (See "Subacromial (shoulder) impingement syndrome", section on 'Pathophysiology'.)

Underlying shoulder dysfunction, including problems with the rotator cuff and scapular stabilizers, contributes to tendon injury within the bicipital grove, below the acromion, or at the labral attachment. The injury may or may not be associated with acute inflammation, and so is referred to as a tendinopathy [11]. Rotator cuff lesions or impingement alters shoulder mechanics, thereby stressing the proximal long head biceps tendon (LHBT) by repetitive tensile overload or tendon instability. Observational studies describe a close correlation between subacromial impingement and biceps tendon disorders [13]. The LHBT suffers a pathologic progression from tendinitis to chronic tenosynovitis to degenerative tendinosis (figure 3). A thickened LHBT from tendinosis can become entrapped within the bicipital groove [14].

Additional mechanisms of injury to the LHBT include medial subluxation of the tendon within the biceps groove (caused by variations in osseous anatomy), compromise of the bicipital sling (covering fascia), and rotator cuff pathology [15]. Congenital anatomic variations of the bicipital groove may predispose the LHBT to subluxation or friction-related tendinitis [15]. Possible variations include a shallow intertubercular groove, a shallow medial wall, and osseous spurs [16,17].

The frequency of LHBT tendon tears (figure 3) increases with age, suggesting that chronic degeneration predisposes to rupture [6]. Rupture of the proximal, long biceps tendon is often associated with rotator cuff tears. The mechanism of injury to the LHBT typically involves a load applied during eccentric contraction of the biceps muscle. Examples include lowering one's body during the decent phase of a pullup, catching a heavy object that falls unexpectedly, or shoveling heavy snow.

The mechanism for distal biceps tendon ruptures also involves eccentric contraction of the biceps muscle. Typically, such injuries involve a sudden forceful extension of the person's flexed elbow when the biceps muscle is already fully contracted [18].

CLINICAL PRESENTATION — Pain from biceps tendinopathy is classically described as focused in the anterior shoulder with radiation distally over the biceps muscle [19]. The pain is aggravated by lifting, pulling, or repetitive overhead activities. However, there is no reliably specific pain pattern for disorders involving the long head biceps tendon (LHBT) [20]. Patients may complain of a painful arc of shoulder motion associated with a click and pain that worsens at night. There may be a history of an inciting event, but usually the symptoms are gradual in onset. Some patients complain of a catching or snapping sensation if instability predominates.  

Whether biceps tendinopathy represents a unique cause of shoulder pain remains a source of debate [2]. Other shoulder ailments (eg, rotator cuff tendinopathy) often coexist.

Acute tendon rupture (figure 3) usually occurs during a specific traumatic event that causes a sudden "pop" accompanied by pain, ecchymosis, and swelling (picture 1). If chronic shoulder pain was present prior to the acute rupture, the patient may report improvement in such pain following rupture of the LHBT. Patients experiencing a proximal LHBT rupture may notice a distinct demarcation of the proximal muscle belly (picture 2). This deformity is commonly referred to as a "Popeye" deformity, named for the cartoon character whose biceps were drawn as a focal bulge in the middle of the upper arm. The deformity is more easily seen in a well-muscled individual and potentially obscured in the obese or elderly with little muscle mass [20].

Patients who sustain a complete distal biceps tendon tear may describe feeling a sudden popping or tearing sensation in the antecubital fossa at the time of injury. In addition, many experience weakness and pain with elbow flexion and supination [15]. Partial tears of the distal biceps exhibit deep antecubital pain worsened by active supination. Unlike LHBT tears, obvious deformity is usually not present.

PHYSICAL EXAMINATION

General approach and overview — Performance of the shoulder examination is discussed in detail separately. The portions of this examination of particular relevance to biceps tendinopathy and tendon rupture are discussed below. (See "Physical examination of the shoulder".)

Examination begins with inspection of both shoulders looking for asymmetry in the biceps muscles, acromioclavicular joint, and anterior shoulder. The neurovascular function of the upper extremities should be assessed in all patients. It is extremely important that the examination is performed with adequate exposure. Subtle muscular atrophy and deformities will be missed if the shoulders remain covered [21].

Various examination maneuvers are used to diagnose biceps tendinopathy or tendon strain. Among the most common are palpation of the long head of the biceps tendon, the Speed test, and the Yergason test (picture 3). We use this combination of tests, along with musculoskeletal ultrasound, to determine the presence of biceps tendinopathy. A biceps tendon rupture is readily identifiable in the large majority of cases using the history, inspection of the arm, and palpation, but ultrasound is a useful adjunct. (See 'Ultrasound' below.)

Long head (proximal) biceps tendon evaluation

Inspection and palpation — The upper extremity of patients with proximal biceps tendinitis or tendinopathy generally appear normal. Examination of a ruptured proximal long head of the biceps tendon (LHBT) performed soon after the injury occurred may show proximal upper arm swelling and ecchymoses. These signs may resolve if the initial presentation is delayed. The "Popeye" deformity is visible as a sagging biceps muscle with a sharp myotendinous demarcation and loss of the usual, more gradual contour of the proximal biceps just below the anterior deltoid. However, rupture can be surprisingly hard to diagnose in obese patients, in whom the classic "Popeye" deformity (picture 2) may be obscured by adipose tissue, and in some elderly patients with little muscle mass.

Palpation over the proximal LHBT at the bicipital groove typically elicits tenderness in patients with tendinopathy. Point tenderness directly over the biceps tendon has long been regarded as pathognomonic for biceps tendon injury. Although one case series found palpation to be neither highly sensitive nor specific, this study assessed for biceps tendon tear only in a select group of patients undergoing arthroscopy [2]. Difficulty in isolating the biceps tendon during physical examination, particularly in patients with significant adipose tissue or muscle overlying the anterior shoulder, may decrease the accuracy of palpation. Some experts suggest that the proximal LHBT is easier to isolate by placing the elbow against the patient's torso and flexed to 90 degrees, with the shoulder externally rotated 30 degrees [21]. We use this positioning (picture 4).

Several methods have been described for improving the accuracy of biceps tendon palpation. We prefer identifying the greater tubercle of the humerus by palpation first, and then moving our fingers slightly medially into the bicipital groove. The shoulder can then be externally and internally rotated while feeling the biceps tendon roll under the examining finger. At this point, extending and flexing the elbow allows for appreciation of tendon movement, and crepitus if present (picture 4 and movie 1). Common problems in examining the biceps tendon include palpating too distally and attempting the examination with the shoulder internally rotated. One study reported poor correlation between direct palpation of the LHBT and identification of tendon position using ultrasound [22]. Clinicians skilled in musculoskeletal ultrasound can use it to identify the biceps tendon and examine it under direct visualization, a standard part of our evaluation. (See 'Diagnostic imaging' below.)

Special tests — Two commonly performed examination maneuvers for biceps injury are the Speed and Yergason tests. To perform the Speed test, the patient's arm is extended in full supination with the shoulder flexed (picture 3). In this position the patient is asked to elevate the arm against a resisted isometric force applied by the examiner (movie 2). A test that elicits pain in the anterior shoulder is considered positive. A review of three studies using the Speed test reported the sensitivity to be 57 percent, specificity 52 percent, and overall accuracy 61 percent [21]. The poor specificity reflects the frequent coexistence of other shoulder pathologies (eg, rotator cuff injury) when biceps tendinopathy is present.

The Yergason test is performed with the patient's arm pronated and flexed at the elbow to 90 degrees (picture 3). The patient then attempts to supinate the arm against a resisted isometric force provided by the examiner (movie 3). Pain localized to the long biceps tendon marks a positive test. Yergason reasoned this test would isolate biceps tendon injury from rotator cuff pathology. A study of 50 patients, using arthroscopy as the gold standard, found the Yergason test to have a sensitivity of 43 percent, specificity of 79 percent, and positive likelihood ratio of 2.05 [23].

The studies described here reflect the general surgical literature, which suggests that neither the Speed test nor the Yergason test provide much help in distinguishing biceps tendon pathology from other causes of anterior shoulder pain [23,24]. In other words, these tests increase the post-test probability of biceps pathology only slightly when positive and when negative do not aid diagnosis.

However, the results of such studies should be interpreted cautiously. These studies include only patients selected for arthroscopy and may not reflect the broader patient population that presents to primary care and sports medicine clinics with shoulder complaints. Furthermore, surgical studies generally focus on the presence of tendon tear to assess the accuracy of physical examination tests. The presence of tendinopathy is more difficult to assess.

One study using MRI as the gold standard for biceps pathology found a sensitivity of 68.5 percent and specificity of 55.5 percent for the Speed test and sensitivity of 37 percent and specificity of 86 percent for the Yergason test [25]. This study is consistent with surgical studies and suggests that physical examination tests have limited accuracy for diagnosing biceps tendon pathology. Of note, MRI itself has demonstrated relatively poor specificity and sensitivity for biceps tendinopathy and partial tendon tears. Using ultrasonography as the standard for biceps tendinitis, sensitivity of the Speed and Yergason tests were only 63 percent and 32 percent, respectively [26]. (See 'Diagnostic imaging' below.)

Distal biceps tendon evaluation

General examination — Inspection of the patient with an acute distal biceps tendon tear soon after the injury typically reveals ecchymosis and swelling over the antecubital fossa, but these signs often resolve by the time the patient presents for medical evaluation [27]. Deformity from a complete tear of the distal tendon – a "reverse Popeye" deformity - is an unreliable finding, as an intact lacertus fibrosis (bicipital aponeurosis) can obscure the underlying retracted biceps tendon [28]. An observational study of 120 patients with traumatic distal biceps tendon injury reported that a retracted distal biceps tear ("reverse Popeye") occurred in only 45 percent of cases [29].

Palpation usually reveals tenderness at the distal biceps tendon, or possibly a tendon stump at the radial tuberosity. However, partial biceps tendon tears may also be tender at these locations [30]. While elbow motion is usually preserved in patients with a distal biceps tendon tear, forearm supination and elbow flexion strength are diminished. Pain increases with resisted elbow flexion or supination.

Special tests — Several maneuvers can be used to evaluate the distal biceps tendon. These include the biceps squeeze, hook test, TILT test, flexion initiation test, and biceps crease interval measurement [27,31]. Each is discussed below.

●Biceps squeeze (movie 4)

●Hook test (picture 5)

●TILT test

●Flexion initiation test (picture 6)

●Biceps crease interval measurement

The biceps squeeze test is similar to the Thompson squeeze test used to assess Achilles tendon integrity. If the distal biceps tendon is intact, a firm squeeze of the biceps muscle causes forearm supination (movie 4). In one observational study, 21 of 22 patients with a positive test had a complete tear of the distal biceps tendon confirmed at surgery [32].

To perform the hook test, the patient flexes the affected elbow to 90 degrees with the forearm fully supinated. The examiner then attempts to "hook" the distal biceps tendon with their index finger and pull it forward (picture 5). An intact tendon moves forward. A partially intact tendon will move forward, but the action is accompanied by pain. If no tendon can be found, this marks a positive test for complete distal biceps tendon rupture [33]. The hook test is subject to false negatives, particularly if the lacertus fibrosus (bicipital aponeurosis) is intact. In an observational study of 202 cases, the sensitivity of the hook test was 78 percent for any tear and 83 percent for complete tears [34].

The principle behind the biceps crease interval measurement is based upon the changes in appearance that result from complete tendon tears, such as the “Popeye” deformity seen with proximal biceps tendon rupture. Complete distal biceps tendon tears cause the muscle belly to retract proximally (or “window-shade”) from the normal anatomic position. The biceps crease interval is a measurement of the distance between the usual, easily identifiable antecubital flexion crease and the distal muscle belly, defined as the palpable cusp of the distal biceps muscle descent. The measurement is made with the elbow fully extended and wrist fully supinated. In a small observational study, an interval measurement greater than 6 cm was reported to have 96 percent sensitivity and 93 percent accuracy for a complete distal biceps tendon rupture [31].

A preliminary, observational study suggests that the TILT test is highly sensitive for diagnosing partial distal biceps tears [35]. This test capitalizes on the change in position of the radial tuberosity, the site of insertion for the distal biceps tendon, when the forearm is supinated versus pronated. The TILT test is performed by palpating the lateral forearm approximately 2 to 3 cm distal to the radial head. A positive test is determined by tenderness at this location when the forearm is fully pronated, while tenderness is absent at the same location when the forearm is fully supinated. A positive test coupled with a negative Hook or biceps squeeze test suggests a partial tear of the distal biceps tendon.

In a retrospective study of 125 consecutive patients with elbow pain, the combination of positive hook and flexion initiation tests was 100 percent sensitive for detecting complete and surgically treatable, partial distal biceps tendon tears (n = 29) [36]. The flexion initiation test (FIT) is performed with the patient seated and their arm fully extended with the forearm supinated (picture 6). The examiner supports the elbow at the olecranon with one hand and places the other hand on the flexor side of the wrist. The patient is asked to initiate flexion against light resistance (approximately 10 to 15 pounds (4.5 to 7 kg) of pressure). Inability to flex the elbow 10 to 15 degrees marks a positive test.

In a cohort study of 86 consecutive patients with suspected distal biceps injury or anterior elbow pain, the combination of a positive Hook test and a biceps crease interval greater than 6 cm was reported to have a sensitivity of 94 percent and specificity 100 percent for complete distal biceps tendon rupture [37]. Specificity was identical for acute and chronic presentations. Use of this test combination may avoid the need for advanced imaging.

DIAGNOSTIC IMAGING

Approach to imaging — Because the initial diagnosis and treatment of both long head biceps tendon (LHBT) tendinopathy and LHBT rupture is typically conservative, advanced diagnostic imaging plays a limited role in the workup. For clinicians trained in musculoskeletal ultrasound (US), this technique has become a standard part of the shoulder examination, including patients with possible LHBT pathology. Despite the limited role of advanced imaging for proximal biceps pathology, magnetic resonance imaging (MRI) may be helpful when the clinical diagnosis is complicated by patient factors (eg, limited physical examination), when there is a need to evaluate for concomitant shoulder pathology (eg, rotator cuff or labral tear), or for surgical planning (eg, planned biceps tenodesis or tenotomy). The short head of the biceps tendon is rarely injured and limited information exists about using US to make this diagnosis.

Conversely, diagnosis of a distal biceps tendon rupture using only clinical signs can be challenging and treatment typically involves expedited surgical repair. Therefore, diagnostic imaging plays an important role in management. When performed by skilled ultrasonographers, US examination of the distal biceps tendon demonstrates sensitivity and specificity for tendon injury that is comparable, if not superior, to MRI [29]. Considering its lower cost and sometimes more timely availability compared with MRI, US can be considered first-line imaging for assessing the LHBT. Nevertheless, in most settings when there is clinical concern for a distal biceps tendon rupture, urgent MRI is performed. (See "Musculoskeletal ultrasound of the elbow", section on 'Anterior elbow'.).

Our approach to diagnostic imaging when either tendinopathy or rupture of the LHBT is our leading diagnosis begins with US, which is an excellent tool for imaging the proximal biceps tendon in the bicipital groove [11,38-43]. Performance of the ultrasound examination of the shoulder, including the biceps tendon, is discussed in detail separately. (See "Musculoskeletal ultrasound of the shoulder".)

Ultrasound — Musculoskeletal ultrasound (US) appears to have high sensitivity and specificity for identifying normal tendons and complete tears of the LHBT. Accuracy is more limited with partial tears and other tendon pathology (eg, tendinopathy) [44]. Performance of the US examination to visualize the proximal and distal biceps tendons is reviewed separately. (See "Musculoskeletal ultrasound of the shoulder" and "Musculoskeletal ultrasound of the elbow".)

US enables the trained clinician to evaluate the structural appearance of bicep tendons and to perform a dynamic examination that allows for comparison with the contralateral shoulder at the bedside. The LHBT can be sonographically assessed from proximal to distal, beginning in the rotator interval, moving through the intertubercular groove (image 1), and ending at the myotendinous junction. The most proximal aspect of the tendon cannot be assessed with ultrasound due to its subacromial position. The normal sonographic appearance of the LHBT exhibits a tightly packed hyperechoic fibrillar pattern of uniform thickness. Pathologic tendons appear hypoechoic, possibly with focally thickened segments. Partial tears display disruptions to the uniform tendon fibers [44]. Signs of structural degeneration, such as loss of normal compact fibular tendon architecture and focal areas of tendon discontinuity or abnormal blood flow, can help to identify tendinopathy and suggest an increased risk for rupture.

Supination and pronation of the forearm, performed either independently or in combination with internal and external rotation of the shoulder, can reveal LHBT subluxation (image 2) or frank dislocation of the tendon from the bicipital groove. LHBT instability is often associated with biceps tendinopathy and tears of the subscapularis tendon. With LHBT rupture, absence of the tendon in the bicipital groove using a short axis view helps to confirm the diagnosis (image 3). Using a long axis view, the presence of a tendon "step-off" along with hypoechoic changes in the soft tissue provides additional confirmatory evidence.

In addition, studies of US in high-risk groups suggest that ultrasound is useful for identifying less pronounced biceps tendon pathology, which may predispose to future injury. As an example, a study of Olympic-level swimmers found that a high percentage showed signs of tendinosis in the LHBT (72 percent) and in the supraspinatus and infraspinatus tendons (96 percent) when screened with US [45]. Specific findings seen in short axis view that are associated with overuse tendinopathy include calcifications within the tendon and hypoechoic changes with thickening. Abnormal "neo-vessels" within the tendon may also develop. When there is fluid within the biceps tendon sheath, this is visible on both short and long axis scan. Significant fluid on short axis may reveal a hypoechoic circle around the more hyperechoic tendon such that the tendon appears like a bullseye. On long axis view, the hypoechoic fluid outlines the superficial and deep surfaces of the tendon. If bicipital peritendinous effusion is found, the ultrasonographer must carefully examine all the major rotator cuff structures, as this finding occurs with rotator cuff pathology [46].

Ultrasound examination of the distal biceps tendon can distinguish complete or high-grade partial tears amenable to surgical repair from low-grade tendinopathy or tear (figure 4 and figure 5). In an observational study using surgical findings as a gold standard, the sensitivity of US for complete, retracted distal tendon tears was over 95 percent [29]. High-resolution US examination performed with specific examination maneuvers can reveal complete distal tendon ruptures and various other tendinous, peritendinous, and osseus pathologies [47].

Additional ultrasound resources — Instructional videos demonstrating proper performance of the ultrasound examination of the shoulder and related pathology can be found at the website of the American Medical Society for Sports Medicine: sports US shoulder pathology. Registration must be completed to access these videos, but no fee is required.

Plain radiographs — Plain radiographs are of little help in assessing biceps tendinopathy or rupture. However, plain radiographs may assist in the evaluation of confounding shoulder pathology and can reveal subacromial spurring or anatomic variants of the acromion that may cause impingement and contribute to proximal biceps tendon pathology. We use plain radiographs for individuals with clinical findings suggestive of degenerative changes or impingement that could complicate the diagnosis of LHBT pathology. Therefore, in patients with a history that includes restricted shoulder motion or mechanical symptoms, such as painful popping or clicking, who also manifest examination findings such as reduced passive range of motion, crepitus, or impingement, we generally obtain plain radiographs of the shoulder. The outlet or scapular Y view allows the clinician to assess acromial architecture. Additional views of the bicipital groove have been described to evaluate the anatomy of the groove and detect spurs, but we feel these are likely to be far less useful than US or MRI [11].

Magnetic resonance imaging — MRI of the shoulder allows for detailed visualization of the biceps tendon and associated shoulder pathology, such as rotator cuff or labral tears. However, the sensitivity and specificity of MRI for diagnosing proximal biceps tendon pathology is limited, and the absence of pathologic findings on MRI is not sufficient to rule out biceps tendon pathology [48-50]. Overall, multiple observational studies report that MRI demonstrates high specificity for complete LHBT tears, but specificity is low for partial tears and for tendinopathy, and sensitivity is low for all pathology [48,51,52]. Patient age may affect the accuracy of MRI. As an example, in an observational study using arthroscopy findings as the gold standard, MRI was found to be less accurate for characterizing lower-grade LHBT injury in subjects aged 41 to 60 years compared with younger cohorts [53]. MRI arthrography appears to be more accurate for identifying LHBT tears, but not tendinopathy [54]. Sensitivity for intra-articular tendon injury is higher if 3 Tesla (3T) MRI is used, particularly if there are two or more pathologic changes, including increased tendon thickness or contour irregularity, or there is higher-grade tendinopathy [55].

Given its limitations, MRI is usually reserved for evaluation of more severe pathology, such as potential labral injuries in the region of the LHBT origin or superior labrum anterior to posterior (SLAP) tears, or for patients whose symptoms persist despite appropriate conservative therapy, possibly including physical therapy and ultrasound-guided injections of analgesics and glucocorticoids [56]. In these instances MRI arthrogram is usually preferred. MRI can also be useful in patients where technical factors limit ultrasound evaluation or for surgeons contemplating operative repair. Given the limits of MRI, it is best to collaborate with the radiologist and possibly the orthopedic surgeon before performing such studies. (See "Superior labrum anterior to posterior (SLAP) tears", section on 'Diagnostic imaging'.)

DIFFERENTIAL DIAGNOSIS

Long head biceps tendon (anterior shoulder pain) — Whether biceps tendinopathy represents a unique cause of shoulder pain remains a source of debate [2]. Biceps tendon injury can be difficult to distinguish from rotator cuff pathology, and the two often coexist. Both may stem from underlying shoulder dysfunction. Therefore, when the diagnosis of biceps tendon injury is considered, it is important to perform a thorough evaluation of the shoulder. Rotator cuff tendinopathy or tear, subacromial impingement, shoulder instability, or labral pathology may be present. (See "Rotator cuff tendinopathy" and "Presentation and diagnosis of rotator cuff tears" and "Subacromial (shoulder) impingement syndrome" and "Multidirectional instability of the shoulder" and "Superior labrum anterior to posterior (SLAP) tears".)

There are many other potential sources of acute and chronic anterior shoulder pain. The diagnostic approach to undifferentiated shoulder pain is discussed in detail separately. (See "Evaluation of the adult with shoulder complaints".)

A few of the more common alternative diagnoses that may present with findings similar to tendinopathy or tear of the LHBT include:

●Rotator cuff pathology ‒ Rotator cuff and LHBT pathology often coexist, and can be difficult to distinguish without performing an imaging study. Patients with anterior shoulder pain whose examination reveals no abnormalities in rotator cuff testing but who manifest a positive Speed or Yergason test are more likely to have isolated tendinopathy of the LHBT. Subscapularis tendon tears are often associated with LHBT subluxation. Examination findings associated with rotator cuff tears include weakness with focal muscle testing, a painful arc of motion (picture 7), and a positive drop arm sign (movie 5). (see "Presentation and diagnosis of rotator cuff tears").

●Glenohumeral osteoarthritis ‒ The patient with glenohumeral osteoarthritis may complain of acute pain flares centered in the anterior shoulder, but symptoms have gradually increased over years and the condition involves adults typically over 60 years of age. Glenohumeral arthritis is differentiated from LHBT injury by the loss of both active and passive shoulder range of motion, and by classic findings (eg, reduced joint space, sclerosis) on plain radiograph. (See "Clinical manifestations and diagnosis of osteoarthritis", section on 'Shoulder'.)

●Adhesive capsulitis ("frozen shoulder") ‒ Adhesive capsulitis presents with clinical findings similar to glenohumeral arthritis but typically occurs in younger patients, classically women in their 40s and 50s with diabetes, but without degenerative changes on radiograph imaging. Both passive and active glenohumeral motion are limited, unlike LHBT pathology where passive glenohumeral motion is usually not limited. In addition, motion restrictions with frozen shoulder most often involve external rotation and abduction, which helps to distinguish the condition from LHBT pathology. (See "Frozen shoulder (adhesive capsulitis)".)

●Acromioclavicular joint pathology ‒ Acromioclavicular (AC) joint pathology, such as an acute AC joint injury or osteolysis of the distal clavicle, generally manifests with focal pain and tenderness at the joint, possibly accompanied by deformity. The LHBT is nontender in cases of isolated AC joint pathology. Pain with the cross body adduction test (picture 8) strongly suggests pathology of the AC joint rather than the biceps tendon. (See "Acromioclavicular joint injuries ("separated" shoulder)" and "Acromioclavicular joint disorders".)

●Referred pain ‒ Referred pain from the cervical spine or brachial plexus may present with some features associated with LHBT pathology, but these can generally be distinguished on clinical grounds. Neurologic pain is often associated with paresthesias and radiates to the neck and arm. Radiation of pain below the elbow suggests radicular pain and makes biceps pathology unlikely. Shoulder pain may also be referred from diseases of the chest (eg, acute coronary syndrome) or abdomen (eg, gallbladder disease). (See "Brachial plexus syndromes" and "Clinical features and diagnosis of cervical radiculopathy" and "Overview of upper extremity peripheral nerve syndromes", section on 'Proximal neuropathies'.)

Distal biceps tendon (anterior elbow pain) — Given the importance of early surgical repair for many patients with a complete distal biceps tendon tear, clinicians must entertain this potential diagnosis for any patient with acute elbow pain and weakness following a relatively forceful biceps contraction. Nevertheless, a number of other conditions may present with symptoms and signs similar to those of distal biceps tendon rupture and these should be considered:

●Tendinopathy ‒ The examination findings of distal biceps tendinopathy are similar to distal biceps tendon rupture but with less pronounced weakness and disability, and pain from tendinopathy typically develops more gradually. Advanced imaging (typically MRI) is needed to establish a definitive diagnosis, when needed.

●Intra-articular pathology ‒ Several types of intra-articular elbow pathology may present similar to distal biceps tendon tear, with elbow pain, range of motion restrictions, and anterior elbow swelling. These include degenerative changes from osteoarthritis, capsular injury, and osteochondral defect or a related loose body (eg, cartilage fragment). Intra-articular elbow pathology is suggested by the presence of a joint effusion and by diminished elbow range of motion. Definitive diagnosis is made with advanced imaging.

●Median mononeuritis ‒ Rarely, median mononeuritis can present primarily as anterior elbow pain. Clinical findings of median neuritis (eg, radiating pain and paresthesias) and electrodiagnostic testing help to distinguish this entity.    

●Bicipitoradial bursitis – The bicipitoradial bursa lies between the distal biceps tendon and radial tuberosity. Bicipitoradial bursitis is relatively uncommon but can present as pain and swelling in the cubital region of the anterior elbow [57,58]. Bicipitoradial bursitis may be associated with distal biceps tendon injury or an independent problem from repetitive activities involving forearm pronation and supination. Diagnosis can be confirmed by MRI or ultrasound imaging of the elbow. 

DIAGNOSIS — Studies to determine the best method for diagnosing tendinopathy of the long head of the proximal biceps tendon (LHBT) are limited. We make the diagnosis primarily based upon clinical findings. Patients who complain of anterior shoulder pain, particularly those who gesture to the area of the long biceps tendon, demonstrate marked asymmetrical and focal tenderness of the tendon compared with the opposite shoulder, and have a positive Yergason test are likely to have tendinopathy of the LHBT. We have found musculoskeletal ultrasound (US) to be a useful diagnostic tool. In addition, US guided injections of analgesics into the bicipital groove can be both diagnostic and therapeutic [56].

The history and examination are generally sufficient to make a preliminary diagnosis of LHBT rupture. However, the sensitivity and specificity of the physical examination for tendon tears is limited, and US is an important tool for confirming the diagnosis in some cases. US reveals a torn or absent tendon in nearly all cases, and in experienced hands can help to identify partial tears and subluxations. Although generally not necessary, MRI can provide a definitive diagnosis.

Distal biceps tendon tear, partial or complete, is more difficult to diagnose than LHBT tear. Clinical findings may be suggestive, but ultrasound or MRI is necessary to make a definitive diagnosis. (See 'Distal biceps tendon evaluation' above and 'Clinical presentation' above.)

INDICATIONS FOR ORTHOPEDIC REFERRAL

Proximal biceps tendon injury — There are no indications for urgent referral for proximal biceps tendon injuries. For the majority of less active patients or older inactive patients, the decrease in strength incurred from a tendon rupture is of little significance. Conservative management is appropriate for this group and referral is generally not needed.

Nevertheless, some patients with proximal biceps tendon rupture are treated with surgical repair. The decision to pursue surgical treatment is based primarily upon the patient's level of function and personal preferences. It is appropriate to obtain orthopedic consultation for proximal biceps tendon ruptures in athletes involved in sports that require significant upper extremity power, patients whose occupation depends to a significant degree upon arm strength, and other highly active patients. Observational data suggests that the loss of the long head biceps tendon (proximal tear) results in a mild to moderate decrease in strength and muscular endurance [59-62], while a rupture of the distal biceps tendon can lead to significant strength loss, particularly with supination [63-65]. Some patients may request repair for cosmetic reasons. For cases that may merit surgical repair, referral should be obtained within two weeks of the injury.  

Patients with significant, chronic LHBT pain that is resistant to conservative treatment may be candidates for biceps tenodesis or tenotomy. Orthopedic referral is appropriate in such instances. However, patients should be advised that evidence supporting the effectiveness of biceps tenodesis and tenotomy is weak, and the procedures are associated with potential complications that can substantially decrease patient satisfaction [66].

Proximal biceps tendon injuries are frequently associated with rotator cuff tears and patients may need surgical intervention to repair such tears. The diagnosis of rotator cuff tear is discussed separately. (See "Presentation and diagnosis of rotator cuff tears".)

Patients with clinical signs of a possible superior labral tear (so-called SLAP lesions) uncovered during the examination should be referred for surgical consultation. SLAP lesions occur at the junction of the biceps tendon and the labrum. In one SLAP variant, the biceps tendon is torn from the glenoid. SLAP lesions are discussed separately. (See "Superior labrum anterior to posterior (SLAP) tears".)

Distal biceps tendon injury — All patients with distal biceps tendon rupture should be referred for surgical consultation as early as possible. Although some patients are treated conservatively with good functional outcomes, these patients can be difficult to identify clinically. Given the potentially significant functional limitations associated with distal biceps tendon injury, expedited surgical referral is recommended.

INITIAL TREATMENT — The immediate care of a biceps tendon rupture involves standard interventions, including the application of ice, compression, and muscle rest, which help reduce hematoma formation and pain. Patient education and discussion of the indications for surgery are important. (See 'Indications for orthopedic referral' above.)

Initial management of biceps tendinopathy involves rest and a brief trial of antiinflammatory medications. Many clinicians give a short course (five to seven days) of oral nonsteroidal antiinflammatory drugs (NSAIDs). We sometimes apply a topical NSAID gel for a locally tender, superficial biceps tendon. Some patients appear to benefit. However, topical NSAID treatment for biceps tendinopathy has not been rigorously studied.

Glucocorticoid injection for tendinopathy — Some clinicians inject glucocorticoid into the subacromial space or the biceps tendon sheath. Subacromial injections may reduce inflammation from subacromial impingement and, if a rotator cuff tear is present, may reduce inflammation in the biceps tendon sheath. Direct injections of the biceps tendon sheath can be technically challenging. The use of ultrasound-guided injection may improve safety and accuracy [67].

The authors often offer glucocorticoid injection into the sheath of the long head biceps tendon (LHBT) under ultrasound (US) guidance to patients with persistent pain (six weeks or more of symptoms), particularly those who have had a poor response to other conservative treatments (eg, NSAIDs, physical therapy, and activity modification). This often provides substantial symptomatic relief and confirms that the LHBT is the source of the shoulder pain.

Distal biceps tendon sheath injections are technically challenging even under US guidance. Without US guidance, the accuracy of injections is limited even when performed by subspecialists [68]. We suggest such injection treatment only in cases of chronic distal biceps tendon pain unresponsive to conservative care and for which advanced imaging (MRI) confirms that surgical treatment is not indicated.

It should be noted that glucocorticoid injections have been associated with tendon rupture. Such ruptures, although often attributed by the patient to the glucocorticoid, may occur spontaneously in a pathologic tendon. Also, postinjection rupture may occur as the patient, relieved of pain, prematurely pursues strenuous activities. We advise patients to avoid any such activity for 72 hours following such an injection. Clinicians should discuss the risk of tendon rupture prior to injection.

FOLLOW-UP CARE

Long head (proximal) biceps tendinopathy — Little evidence exists to guide the nonsurgical management of biceps tendinopathy. The approach described below is based upon observational data and our clinical experience [19].

A follow-up interval of two to four weeks for acute biceps tendinopathy is reasonable. This interval allows the clinician to assess the effectiveness of initial conservative care, and to implement more aggressive treatment as needed. Nonsteroidal antiinflammatory drugs (NSAIDs) and activity modification continue during this interval.

If symptoms associated with biceps tendinopathy are long-standing or unresponsive to initial conservative management, many clinicians suggest a trial of physical therapy. Treatment typically includes local therapies for symptom relief and a careful assessment of biomechanical faults, including the entire kinetic chain involved in the patient's major activities that may be contributing to injury. Biceps tendinopathy is often accompanied by rotator cuff pathology. Therefore, physical therapy generally involves range of motion and strengthening exercises for the biceps, rotator cuff, and scapular stabilizer muscle groups. Physical therapy for these conditions is reviewed in detail separately. (See "Rehabilitation principles and practice for shoulder impingement and related problems".)

In addition to physical therapy, injection of an analgesic and glucocorticoid into the long head of the biceps tendon (LHBT) sheath under ultrasound guidance may be performed at this stage, if not already done (as described above). (See 'Initial treatment' above.)

If there is no improvement, or the diagnosis remains unclear, advanced imaging (generally MRI) is performed. (See 'Diagnostic imaging' above.)

A number of potential treatments for biceps tendinopathy have been reported but the supporting evidence for these is limited. Some clinicians use iontophoresis with dexamethasone. Other therapeutic approaches include therapeutic ultrasound, extracorporeal shock wave, phonophoresis, topical nitroglycerin, low level laser, dry needling, platelet rich plasma, and taping [56]. (See "Overview of the management of overuse (persistent) tendinopathy".)

Proximal long biceps tendon tear initially managed nonsurgically — Many patients with a complete LHBT tear are managed nonsurgically and regain more than adequate strength to perform their preferred activities through physical therapy. Follow up for an isolated proximal biceps tendon rupture managed nonsurgically is performed if necessary for persistent pain, disability, or cosmetic concerns. If such ruptures are associated with persistent pain or disability, the patient should be referred to an orthopedic surgeon. (See 'Indications for orthopedic referral' above.)

Distal biceps tendon tear — All distal biceps tendon tears are referred to an orthopedic surgeon. Most are treated surgically, but some are managed with activity modification, physical therapy, and symptomatic treatment (eg, NSAIDs, glucocorticoid injection).

COMPLICATIONS — The main complication of biceps tendinopathy is biceps tendon rupture. Patients with long-standing biceps tendinopathy who remain active in activities requiring forceful biceps contraction are at ever-present risk of rupturing the tendon.

With long head biceps tendon rupture (proximal tear), patients may experience persistent pain with certain activities and reductions in muscle strength and endurance of up to 25 percent [59-62]. Through physical therapy, patients can regain a degree of this lost strength but some deficit will persist. However, for the majority of patients the strength loss is insignificant and does not interfere with daily activities. Patients with persistent pain or disability following a proximal biceps tendon rupture should be referred for orthopedic evaluation. (See 'Indications for orthopedic referral' above.)

RETURN TO SPORT OR WORK — When pain-free range of motion is achieved, the patient can begin a gradual, step-by-step return to activity and sport. Physical therapy often plays an important role in improving the strength and flexibility of the biceps and shoulder muscles (eg, rotator cuff), which often contribute to the patient's symptoms [14].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: General issues in muscle and tendon injury diagnosis and management" and "Society guideline links: Muscle and tendon injuries of the upper extremity (excluding shoulder)" and "Society guideline links: Shoulder soft tissue injuries (including rotator cuff)".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: Biceps tendinopathy (The Basics)")

●Beyond the Basics topic (see "Patient education: Biceps tendinitis or tendinopathy (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Types of injury and differential diagnosis – Biceps tendon injuries represent a spectrum of disorders including tendonitis, tendinopathy (or tendinosis), subluxation, partial tears, and complete tears. Proximal long head of the biceps tendon (LHBT) injuries are most common. Proximal biceps tendon injury can be difficult to distinguish from rotator cuff pathology, and the two often coexist. Shoulder instability, impingement syndrome, or labral injuries may also be present. Evaluation for coexisting pathologies should be performed when entertaining the diagnosis of biceps tendon injury. (See 'Epidemiology and risk factors' above and 'Mechanism of injury' above and 'Differential diagnosis' above.)

●Clinical presentation of tendinopathy – Pain from LHBT tendinopathy is often focused in the anterior shoulder; the pain may radiate distally over the biceps muscle. Symptoms are gradual in onset and often aggravated by lifting, pulling, or repetitive overhead activities. Patients may complain of a painful arc of motion associated with a click, and pain that worsens at night. (See 'Clinical presentation' above.)

●Clinical presentation of tendon tear – Acute LHBT rupture usually occurs during a specific traumatic event that causes sudden pain, a "pop" in the shoulder, ecchymosis, swelling, and abnormal tendon appearance (picture 2). Acute tear of the distal biceps tendon is much less common. It is often accompanied by a popping or tearing sensation in the antecubital fossa at the time of injury, and many patients experience weakness and pain with elbow flexion and supination. Unlike LHBT tears, obvious deformity is usually not present. (See 'Clinical presentation' above.)

●Physical examination – The most commonly used tests for making the diagnosis of LHBT injury are tendon palpation (picture 4 and movie 1), the Speed test (movie 2), and the Yergason test (picture 3). Evidence supporting the accuracy of these tests is limited; the Yergason test is relatively specific for biceps tendon injury but lacks sensitivity. Examination findings associated with distal tendon injury are less reliable. (See 'Physical examination' above.)

●Diagnosis – We diagnose LHBT tendinopathy based primarily upon clinical findings. Patients who complain of anterior shoulder pain, particularly those who gesture to the area of the LHBT, demonstrate marked asymmetrical tenderness of the tendon compared with the opposite shoulder, and have a positive Yergason test are likely to have biceps tendinopathy. (See 'Diagnosis' above.)

●Diagnostic imaging for proximal biceps tendon – Advanced diagnostic imaging plays a limited role in the initial workup of both LHBT tendinopathy and rupture. Ultrasound enables the trained clinician to evaluate tendons in motion and to compare them with the contralateral shoulder. Ultrasound has high sensitivity and specificity for complete tears of the LHBT. MRI provides detailed visualization of the biceps tendon, but its sensitivity and specificity are limited for some conditions involving the proximal biceps tendon; it is usually reserved for evaluation of more severe or prolonged symptoms. (See 'Diagnostic imaging' above.)

●Diagnostic imaging for distal biceps tendon – Diagnosis of a distal biceps tendon rupture using only clinical signs can be challenging, and therefore, diagnostic imaging plays an important role in the initial workup. Ultrasound may be useful, but MRI is often necessary. (See 'Diagnostic imaging' above and 'Distal biceps tendon (anterior elbow pain)' above and 'Diagnosis' above.)

●Treatment – Rest from aggravating activities, local or systemic nonsteroidal antiinflammatory drugs (NSAIDs), physical therapy, and subacromial or biceps tendon sheath injections form the core of conservative care for LHBT tendinopathy. Physical therapy generally involves range of motion and strengthening exercises for the biceps, rotator cuff, and scapular stabilizer muscle groups. (See 'Initial treatment' above and 'Follow-up care' above.)

●Indications for orthopedic referral – There are no indications for emergency referral for biceps tendon injuries. Referral may be necessary for patients with significant biceps tendon pain that has been resistant to conservative treatment and some patients with cosmetic concerns. (See 'Indications for orthopedic referral' above.)

•Proximal biceps tendon rupture – For most less-active patients or older inactive patients, the decrease in strength incurred with a proximal LHBT rupture is of little significance and conservative management is appropriate. Orthopedic consultation is appropriate when proximal biceps tendon rupture occurs in athletes involved in sports that require significant upper extremity power, patients whose occupation depends to a significant degree upon arm strength, and some other highly active patients.

•Distal biceps tendon rupture – Patients with a distal biceps tendon rupture should be referred for surgical consultation as early as possible, as some will require surgical repair.