CASE 59

By: Dr. Ahmad M. Aljefri M.B.B.S

HISTORY: Sudden onset arm pain.

What are your findings?

What is the differential diagnosis?

What are the causes?

FINDINGS:

Gray-scale sonographic images of the antecubital fossa demonstrate loss of the normal appearance of the distal biceps tendon near its insertion on the bicipital tuberosity. A pocket of fluid is noted anterior to the radial neck. Midline sagittal images demonstrating a thickened and irregular appearance of the tendon with further retraction when the patient is instructed to perform active elbow flexion.

Coronal STIR sequence through the elbow demonstrating an empty appearance of the bicipital tuberosity with retraction of the biceps tendon above the level of the elbow joint on the sagital T1 weighted images.

DIAGNOSIS:

Traumatic distal biceps tendon rupture.

PEARLS AND DISCUSSION:

The distal biceps tendon forms at a variable distance above the elbow joint with two insertions distally to the radial bicipital tuberosity and to the lacertus fibrosus, which in turn inserts on the deep fascia of the forearm. The distal 1-2 cm of the tendon is relatively hypovascular rendering it more susceptible for degeneration and tears.

The distal biceps tendon is prone to incomplete and complete tears. Incomplete tears are usually caused by relatively minor trauma and usually in degenerative tendons. Complete tears, on the other hand, are caused when a relatively strong force is applied while the elbow is being held at 90 degrees flexion against resistance.

The diagnosis of biceps tears is usually clinical evident and imaging helps in confirming the diagnosis and also in surgical planning. Both ultrasound and magnetic resonance imaging are appropriate and are of equal sensitivities and specificities.

FURTHER READING:

1. Chew, Michael L., and Bruno M. Giuffrè. Disorders of the Distal Biceps Brachii Tendon. Radiographics 25.5 (2005): 1227-1237.

2. Perrich, Kiley D. (n.d.). Optimal Positioning for MRI of the Distal Biceps Brachii Tendon: Flexed Abducted Supinated View: American Journal of Roentgenology: Vol. 182, No. 4 (AJR).

3. Clarissa Canella (n.d.). The Role of Sonography in Differentiating Full Versus Partial Distal Biceps Tendon Tears: Correlation With Surgical Findings: American Journal of Roentgenology: Vol. 200, No. 1 (AJR).

4. Lucas Da Gama Lobo (n.d.). Sonography of Tears of the Distal Biceps Tendon: American Journal of Roentgenology: Vol. 175, No. 4 (AJR).