The biceps muscle consists of 2 heads (short and long heads) that originate from 2 different locations at the shoulder.
At the lower end of the biceps muscle is the distal biceps tendon which crosses the elbow joint and inserts onto the radius. The role of the biceps muscle is to assist other muscles with elbow flexion and it is the most important muscle responsible for forearm supination (turning the hand outward to face the palm upwards).
Distal biceps tendon ruptures are fairly rare, with only 10% of biceps ruptures occurring distally at the elbow. It most commonly occurs in 40-50-year-old men, at the dominant elbow. There are certain risk factors for developing a distal biceps tendon rupture, such as smoking (7.5 times increased risk) and the use of anabolic steroids. Anabolic steroids change the collagen content in tendons which reduces the elasticity of tendons, making them more prone to injury.
Diagnosis and work-up:
The distal biceps tendon usually tears when a flexed elbow is forced into extension. The patient will usually feel something “pop” and may notice sudden weakness in elbow flexion. Bruising and swelling develop over the front and inner aspect of the elbow and gradually spreads up and down the arm.
The biceps muscle belly contracts and forms a bulge in the upper arm with an emptiness just above the elbow crease (the “Reverse Pop-eye” sign). The diagnosis is usually made during the examination of the elbow, but if there is any doubt an MRI is the investigation of choice to define the tear size and assess the amount of tendon retraction.
Acute distal biceps tendon ruptures are best treated surgically to reattach the torn tendon. Otherwise, supination strength (as required when turning a screwdriver) and to a lesser extent elbow flexion strength will be impaired. Conservative treatment is reserved for certain partial thickness tears and can be considered in older, less active patients or patients not fit for surgery. Partial-thickness tears may initially be treated with an elbow splint for 2 weeks.
Pain killers and anti-inflammatory medication can be taken as needed. During the first few days, an ice pack can be applied for 15-20 minutes at a time to reduce swelling. Start with a gentle active-assisted range of motion (using your opposite arm to move your affected elbow) and progress to active elbow flexion when pain allows.
As mentioned before, the recommended treatment for distal biceps tendon ruptures is surgery. It is performed under a general anesthetic (meaning you are asleep during the procedure). Various techniques are described using one or two incisions to reattach the torn tendon. Dr. Grey uses a single incision technique.
A single horizontal incision of about 4cm is made over the front of the upper forearm. The distal biceps tendon is often retracted (especially in more chronic cases) and needs to be released to allow the tendon end to reach the insertion point on the radius (the bicipital tuberosity). The tendon end is retrieved through the skin incision and sutures are weaved back and forth through the last 2cm of the tendon. The suture ends are passed through a small metal button which is subsequently passed through a hole drilled in the bicipital tuberosity.
As the sutures are tightened, the biceps tendon is pulled into the hole in the bicipital tuberosity (see image). With very old injuries, the distal biceps tendon may be so contracted and scarred that it won’t reach the radius, and a distal biceps tendon reconstruction may be required, using a hamstring tendon graft. The skin incision is closed in layers and a dressing and backslabs (splint) is applied that will stay on for 14 days.
Rehabilitation protocol after Distal Biceps tendon repair is available in our Rehab Protocols section here: