The biceps brachii muscle is a flexor and supinator of the forearm. The muscle has two proximal attachments with the short head originating on the coracoid process and the long head just above the glenoid. The distal attachment is on the tuberosity of the radius (Fig. 15–8). Disruption of this muscle unit is not uncommon because, like the gastrocnemius and hamstring muscles, it has exposure to greater potential forces because it crosses two joints. Disruption can occur at the long head of the biceps tendon, the musculotendinous portion, muscle belly, or the distal attachment. Rupture of the long head of the biceps tendon is most common, whereas muscle disruption is least common.14 The presentation, whether proximal or distal disruption is present, is that of a “Popeye”-shaped upper arm (Fig. 15–9).
The anatomy of the biceps brachii muscle.
A patient with rupture of the biceps tendon. Note the “Popeye” appearance of the muscle.
Long Head of the Biceps Tendon Rupture
Rupture of the long head of the biceps can occur anywhere along its route. The condition often occurs in men during their sixth or seventh decade of life following a chronic bicipital tenosynovitis that has left the tendon weakened. In younger patients, it may occur more suddenly, following forceful contraction of the biceps during lifting an object (e.g., weight lifting).15–17
The patient usually notices an immediate sharp pain in the region of the bicipital groove and the biceps is noted to bulge within the arm. There is tenderness to palpation within the bicipital groove. The diagnosis can be confirmed by asking the patient to contract the biceps with the arm abducted and externally rotated to 90 degrees, at which point flexion at the elbow will cause the biceps to move away from the shoulder.18
For definitive treatment, surgical reattachment to the bicipital groove is recommended in most active patients. In elderly patients with the condition, repair may not be indicated. If the decision is made not to repair the tendon, negatives include the cosmetic appearance of the arm and a loss of elbow flexion strength of approximately 10% to 20%, which is usually well tolerated.18,19
Patient with an acute rupture of the biceps muscle belly are treated conservatively in a Velpeau bandage with the elbow flexed to 90 degrees (Appendix A–13).
Distal Biceps Tendon Rupture
Distal biceps tendon rupture is most common in the dominant arm in men between 40 and 60 years and occurs as a result of a sudden eccentric load with the elbow flexed.20,21 This injury is less common than proximal disruption, accounting for 3% of biceps tendon injuries, although it seems to becoming more common possibly due to an increase in the activity level of patients in their fifth and sixth decades.22,23
Usually, there is a history of a tearing sensation accompanied by pain in the region of the antecubital fossa. Similarly to the long head of the biceps rupture, patients will present with a visible deformity of the muscle belly and weakness to flexion and supination. Partial tears may not present with the same muscle retraction and deformity, and are therefore more difficult to diagnose. Distal biceps tendon integrity can be assessed with the “hook test” where the examiner hooks their index finger under the lateral aspect of the distal biceps tendon (Video 15–1).24 The squeeze test is analogous to the Thompson test for Achilles tendon rupture. With the forearm slightly pronated and resting on the patient’s leg, the examiner squeezes the biceps and should note the slight supination of the forearm if the distal biceps tendon is intact (Video 15–2). The biceps crease interval, the distance between the antecubital crease and the distal biceps muscle, can also be measured. More than 6 cm or a 20% increase in the affected arm is abnormal (Fig. 15–10). If the diagnosis is unclear, ultrasonography or MRI may be useful.
Video 15-1: Performance of the “hook test” for evaluation of biceps tendon integrity.
The examiner inserts the index finger under the lateral aspect of the biceps tendon while the patient attempts to flex the elbow and supinate the forearm against resistance. To elicit this motion you can ask them to “turn a doorknob and pull the door towards you while immobilizing their hand on the affected side. Positive findings include significant pain in the antecubital fossa with the attempt, or failure to palpate the tendon.
Video 15-2: Normal squeeze test.
If distal biceps tendon rupture is present, supination of the forearm would not be seen.
Distal biceps tendon rupture. Note the increased distance from the antecubital crease to the distal edge of the biceps muscle in the abnormal extremity.
Acute complete rupture of the distal tendon of the biceps is treated with early surgical reattachment to maintain strength.22,23 Partial tears are initially treated conservatively with immobilization. Surgical repair is reserved for refractory dysfunction.25
The triceps brachii muscle consists of three muscle groups that collectively insert on the olecranon process to extend the elbow and, to a lesser extent, adduct the arm. The long head of the triceps originates on the infraglenoid tubercle of the scapula. The medial head originates from the posterior humerus and radial groove. The lateral head originates on the posterior humerus lateral to the radial groove (Fig. 15–11).
The anatomy of the triceps brachii muscle.
Triceps tendon rupture is very rare, representing less than 1% of tendon injuries. The mechanism is usually a fall against an outstretched arm while the triceps is contracted with or without a blow to the posterior elbow. Hyperparathyroidism secondary to renal failure, olecranon bursitis, anabolic steroid use, or weight lifting may be contributing factors.26
The tendon is usually disrupted at the insertion into the olecranon and the injury can be associated with an avulsion fracture of the olecranon. The patient presents with posterior elbow swelling and tenderness with an inability to extend the elbow against gravity. These injuries may be missed as pain in the posterior elbow limits motion at the time of injury and swelling prevents palpation of the gap caused by withdrawal of the tendon.
Treatment involves splinting at 30 degrees of elbow flexion and urgent orthopedic consultation. Most patients require surgical repair.26–29
There are three compartments of the upper arm. The anterior flexor compartment contains the biceps and brachialis muscles, whereas the posterior extensor compartment contains the triceps. The deltoid muscle is surrounded by its own fascia and is the third compartment.
Compartment syndrome of the upper arm is unusual and much less common than in the forearm and leg. There are several explanations for the infrequent incidence of this condition. The fascia of the upper arm musculature is thinner and more distensible. In addition, the muscles of the arm communicate with the shoulder.30
Nonetheless, upper arm compartment syndrome has been reported after muscle contusion, humerus fracture, subcutaneous injection, shoulder dislocation, tendon rupture, steroid use, exercise, blood pressure monitoring after thrombolytic therapy, as a complication of dialysis access, secondary to anticoagulant use, and tourniquet use.31–38
The clinical presentation is similar to other locations, except that upper arm compartment syndrome may not be as obvious or appear as quickly, making this condition potentially easily missed. Diagnostic measures and treatment are similar to compartment syndrome in other locations and the reader is referred to the discussion in Chapter 4 for further information.
Contusions of the muscles of the upper arm are common but not disabling injuries with no major complications. The treatment of these injuries is a sling for protection. Ice in the first 24 hours is recommended followed by heat.
The physician should rule out an underlying fracture and test for injury to the radial nerve from a contusion to the lateral aspect of the distal arm. Contusion of the radial nerve as it courses in close approximation to the humerus along the spiral groove is an infrequent injury. As the nerve courses further, it goes laterally above the lateral epicondylar ridge and is subject to contusions by a direct blow. The patient complains of a tingling sensation extending down the forearm and into the hand over the distribution of the nerve. The treatment is symptomatic.
Patients with repeated contusions to the arm may develop ectopic bone deposition. Anterior lateral humeral exostosis, also called blocker’s exostosis because of its association with American football lineman, is an abnormal deposition of bone at the attachment of the deltoid muscle onto the humerus. The injury is initiated by a direct blow in this region that produces a contusion and periostitis at the insertion of the deltoid tendon. Later, a potentially painful and irritative exostosis develops at the site of injury. When significant discomfort occurs, the patient should be referred for consideration of excision.