The Clinical Syndrome

Rupture of the distal tendon of the biceps occurs much less frequently than rupture of the long head of the biceps. Proximal rupture of the tendon of the long head of the biceps tendon accounts for more than 97% of biceps tendon ruptures, whereas ruptures of the distal portion of the biceps tendon occur less than 3% of the time. Occurring most commonly in men in the forth to sixth decades, disruption of the distal biceps tendon is usually the result of an acute traumatic event secondary to a sudden eccentric load on the tendon, such as trying to start a recalcitrant lawn mower, practicing an overhead tennis serve, lifting weights, or performing overaggressive follow-through when driving golf balls ( Fig. 40.1 ). Falls on a flexed and supinated elbow have also been associated with tears and rupture of the distal biceps tendon, as has abuse of anabolic steroids in athletes.

Patients with tears of the distal biceps tendon experience weakness of flexion and supination of the affected extremity.

The biceps muscle and proximal and distal tendons are intimately involved in shoulder and elbow function and are susceptible to trauma and to wear and tear. If the damage is severe enough, the distal tendon of the biceps can rupture, leaving the patient with a palpable defect in the antecubital fossa and weakness of upper extremity flexion and supination ( Fig. 40.2 ).

A 49-year-old man, 2 years following nonoperative management of a complete avulsion of the right distal biceps tendon. A deficit of distal biceps brachii mass in the right distal arm is clearly seen.

(From Hetsroni I, Pilz-Burstein R, Nyska M, et al. Avulsion of the distal biceps brachii tendon in middle-aged population: is surgical repair advisable? A comparative study of 22 patients treated with either nonoperative management or early anatomical repair. Injury . 2008;39(7):753–760.)

Signs and Symptoms

In most patients, the pain of distal biceps tendon tear occurs acutely, is often quite severe, and is accompanied by a pop or snapping sound. The pain is constant and severe and is localized to the region surrounding the antecubital fossa. Patients with complete distal biceps tendon tear experience weakness of upper extremity flexion and supination. An obvious defect is palpable in the antecubital fossa in patients with complete rupture of the distal biceps tendon. A reverse Popeye sign is usually present (see Fig. 40.2 ).

Testing

Plain radiographs are indicated for all patients who present with elbow pain. Based on the patient’s clinical presentation, additional testing may be indicated, including a complete blood count, erythrocyte sedimentation rate, and antinuclear antibody testing. Ultrasound imaging may help further delineate the extent of tendinopathy and identify other abnormalities responsible for the patient’s pain and functional disability ( Fig. 40.3 ). Magnetic resonance imaging of the elbow is indicated if tendinopathy or if partial tear or complete rupture of the biceps tendon is suspected ( Fig. 40.4 ).

Longitudinal ultrasound image demonstrating tearing and edema of the distal biceps tendinous insertion.

T2-weighted magnetic resonance imaging of a distal biceps tendon tear. A, Sagittal image with a retracted tendon stump. B, Axial image with visible hemorrhage surrounding the insertion site at the bicipital tuberosity of the proximal radius.

(Courtesy Glenn M. Garcia, MD, Department of Radiology, University of Texas Health Science Center, San Antonio. From Huber FG. Arm. In: DeLee JC, Drez DD, Miller M, eds. DeLee and Drez’s Orthopaedic sports medicine: principles and practice . 3rd ed. Philadelphia: Saunders; 2010:1169.)

Differential Diagnosis

Tear of the distal biceps tendon is usually a straightforward clinical diagnosis. However, coexisting bursitis or tendinitis of the elbow from overuse or misuse may confuse the diagnosis. In some clinical situations, consideration should be given to primary or secondary tumors involving the elbow. Nerve entrapments of the elbow and forearm can also complicate the diagnosis.

Treatment

Initial treatment of the pain and functional disability associated with distal biceps tendon tear includes a combination of nonsteroidal antiinflammatory drugs (NSAIDs) or cyclooxygenase-2 (COX-2) inhibitors and physical therapy. Local application of heat and cold may also be beneficial. For patients who do not respond to these treatment modalities and who appear to have significant local pain in the region of the distal biceps tendon, careful injection with local anesthetic and steroid is a reasonable next step.

Injection for distal biceps tendon tear is carried out by placing the patient in the sitting position with the elbow flexed to approximately 90 degrees. If intact, the distal biceps tendon is easily identified by palpation at the antecubital fossa. If the tendon is absent, the area of defect is identified. The point overlying the distal tendon or defect is marked with a sterile marker. The skin overlying antecubital fossa is then prepared with antiseptic solution. A sterile syringe containing 1 mL of 0.25% preservative-free bupivacaine and 40 mg methylprednisolone is attached to a -inch, 25-gauge needle using strict aseptic technique. The previously marked point is palpated, and the distal biceps tendon or area of defect is reidentified with the gloved finger. The needle is carefully advanced at this point through the skin and subcutaneous tissues until it impinges on the distal biceps tendon or enters the area of defect. The needle is then withdrawn 1 to 2 mm out of the substance of the tendon, and the contents of the syringe are gently injected. Slight resistance to injection should be felt. If no resistance is encountered, the tendon is ruptured. If resistance is significant, the needle tip is probably in the substance of the tendon and should be advanced or withdrawn slightly until the injection can proceed without significant resistance. The needle is then removed, and a sterile pressure dressing and ice pack are applied to the injection site. Recent clinical experience suggests that the injection of type A botulinum toxin and platelet-rich plasma and/or stem cells may provide improved symptom relief and healing of tendinopathy of the distal biceps tendon. Ultrasound guidance may improve the accuracy of needle placement in patients in whom anatomic landmarks are hard to identify

Physical modalities, including local heat and gentle range-of-motion exercises, should be introduced several days after the patient undergoes injection. Vigorous exercises should be avoided, because they will exacerbate the patient’s symptoms. Occasionally, surgical repair of the tendon is undertaken if the patient is experiencing significant functional disability or is unhappy with the cosmetic defect caused by the retracted tendon and muscle.