Injuries to the distal biceps tendon are relatively uncommon. When the do occur, it most often occurs in men between 40 and 60 years of age. Although partial biceps tendon injuries can be treated with rest and rehabilitation, complete distal biceps injuries are usually treated with surgery, and return to activity may be delayed for up to five to six months after surgery.
The biceps muscle is important for bending and rotation of the forearm. The biceps muscle has two tendons that originate at the level of the shoulder, and a single tendon that inserts into the radius, one of the bones in the forearm.
Because of its position, this muscle and tendon is important for flexion (bending) of the elbow, but its most important function is supination (rotating forearm with the palm up).
Injury to the distal biceps usually occurs after force is applied to the forearm, with the elbow bent at 90 degrees with the palm up. Most commonly, this occurs when lifting a heavy object.
This injury is more commonly seen in men between their 40s and 60s. There may be multiple causes including lack of adequate blood supply to the tendon or multiple small injuries to the tendon. Immediately after the injury, patients may experience difficulty bending the arm but rotating the forearm may prove to be more difficult.
The initial presentation will include swelling and bruising at the front of the elbow as well as pain. There may be a palpable defect at the anterior elbow, but if the tendon is only partially torn, it may feel intact. Patients will experience difficulty with bending and rotation of the forearm. In complete tears, the muscle may even retract into the arm producing a bulge in the arm.
Usually this is a clinical diagnosis, but MRI may be useful if there is suspicion of a partial tear. An MRI may help differentiate a partial tear from bursitis or tendon irritation.
The most common treatment for this injury is to repair or reconstruct the tendon as it inserts onto the forearm. The biceps tendon may be repaired if the injury is recent, but if there is a delay in diagnosis, the muscle may retract and there may be significant scar formation. In those cases, the tendon may need to be reinforced with a graft (donor tendon). The tendon is fixed to the radius with a small anchor and heavy sutures. The procedure is an outpatient procedure, and the patient is in a splint in order to protect the arm following surgery.
Recovery after surgery will vary depending on treatment. Due to the nature of the repair, patients should not expect strengthening exercises for up to 6 weeks after surgery in order to allow the repair to properly heal to the bone. Depending on the surgeon’s recommendation, patients may not be able to return to regular activity until 5 to 6 months after surgery.