History
Patients with biceps rupture may report a wide variety of symptoms, including the following:
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Some patients report sudden anterior shoulder pain or elbow pain during activity. This acute pain, frequently described as sharp in nature, may be accompanied by an audible pop or a perceived snapping sensation, depending on the location of the rupture.
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In proximal biceps tears, some people may experience recurrent pain while performing overhead or repetitive activities that require elbow flexion, while others may experience only a nondescript anterior shoulder soreness that may worsen at night. In some patients, pain may diminish when a complete rupture occurs following chronic impingement and irritation.
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In both proximal and distal biceps tendon tears (more so in distal tears), a visible or palpable mass may be appreciated (“Popeye deformity”). However, not all biceps tears, especially those involving the long head of the biceps tendon, demonstrate a palpable mass. A deformity may not be present due to scarring of the rotator interval, the subscapularis tendon, or the tendon in the bicipital groove.
Physical
When a proximal or distal biceps rupture is suggested on the basis of history or mechanism of injury, physical examination should include specific testing of all types of shoulder and elbow pathology within the large list of possible diagnoses. Because biceps ruptures are often the final event in a cascade of impingement and inflammation, testing for impingement syndromes and bicipital tendonitis is always warranted, with a thorough examination made of the upper extremity. An examination can be carried out as follows:
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Perform an examination to identify any palpable tenderness along the course of the biceps tendons and muscle belly, including the bicipital groove, with the arm in 5-10º of internal rotation; look for the "Popeye sign," a distal anterior humeral regional bulging of the biceps muscle
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Perform range-of-motion (ROM) testing of the shoulder and elbow
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Perform complete strength testing of upper limb muscles, especially the biceps
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Inspect the shoulder and arm contour and compare with the contralateral side; pay special attention to the region of the bicipital groove, which may show indentation or hollowing when the tendon is absent following a rupture; the Ludington test (or position), in which the hands are clasped behind the head and the biceps muscles are flexed, is often used for this purpose
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Utilization of the “Hook test,” with the patient’s shoulder elevated, elbow flexed, and arm supinated, aides in determining if the distal biceps tendon is intact; [13] an inability to “hook” the biceps tendon is considered a positive test for a complete rupture, while reproduction of pain with palpation of the biceps tendon is indicative of a partial tear [14]
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Other maneuvers, such as the Speed test and checking for a positive Yergason sign, are used, along with signs of biceps dislocation or instability, to identify patients who may have partial tears or may be predisposed to future rupture
Causes
A proximal biceps rupture generally is caused by insidious inflammation from impingement in the subacromial region and may be the eventual result of chronic microtrauma. Typically, proximal biceps tendon tears occur in the elderly, but younger individuals may suffer a proximal tear following a fall or during heavy weightlifting or sports activities. [12, 2] On the other hand, distal biceps tendon tears typically occur in the middle-aged (aged 35-54 years) population. However, acute traumatic ruptures of the proximal or distal biceps tendon may occur in anyone engaged in predisposing activities.
Ruptures of the proximal biceps tendon make up 90-97% of all biceps ruptures and almost exclusively involve the long head. [11] Repeated insults often lead to fraying of the tendon, with resultant weakness predisposing it to rupture following relatively minor injuries. A distal biceps rupture is typically due to an excessive eccentric overload at the elbow. [2] In that moment, the biceps actively contracts as the elbow is forcibly extended. [13]
A tendon rupture due to chronic inflammation can occur in rheumatoid arthritis. Additional causes of chronic inflammation with associated predisposition to tendon rupture include the following:
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Diabetes mellitus
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Chronic kidney disease
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Chronic steroid use
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Systemic lupus erythematosus (SLE)
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Fluoroquinolone antibiotics
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Cigarette smoking
Biceps tendon rupture or degeneration is frequently associated with rotator cuff trauma in the geriatric population and is often observed at the time of surgery for complete rotator cuff tears. This may be related to an impingement phenomenon. [15, 16, 17]
Vestermark et al found a strong association between acute rupture of the long head of the biceps tendon and rotator cuff disease, determining that evidence of rotator cuff disease existed in 93% of patients with such ruptures (mean age 61.0 y). Most of the rotator cuff disease cases involved full-thickness tears of the supraspinatus tendon. [18]
The association between biceps rupture and rotator cuff disease was also explored by Kowalczuk et al, who, in a retrospective study, found that of 116 patients with proximal long head biceps rupture, 99 (85%) displayed supraspinatus or subscapularis tendon tearing. Patients with rotator cuff pathology had a significantly higher mean age (63.3 y) than did those without it (54.2 y). The investigators also found that the supraspinatus tendons had a higher incidence of full-thickness tears than did the subscapularis tendons (44% vs 21%, respectively). [19]
Most biceps ruptures occur at the tendinous insertion to the bony anchor, proximally and distally. [20, 21]
Distal avulsions from the radius are commonly caused by chronic irritation on an irregular surface, such as in persistent cubital bursitis. Acute avulsions are the result of forceful extension of the elbow from a flexed and supinated position.
Rare short-head rupture may occur with rapid flexion and adduction of the arm during elbow extension activities.
Impairment of physiologic repair mechanisms by medications (statins) has also been proposed as a potential factor predisposing the tendon to rupture. [22]
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Biceps muscle and tendons
