Biceps Tenosynovitis

The biceps tendon attaches onto the shoulder blade bone (scapula), passes through the shoulder joint and then through a groove in the top of the humerus bone (bicipital groove). The tendon widens into the belly of the biceps muscle and then attaches into the radius and ulna bones of the forelimb. Contraction of the biceps muscle flexes the elbow and extends the shoulder joint.

What is Biceps Tenosynovitis
Biceps tenosynovitis is inflammation of the tendon of the biceps muscle (same muscle that we have in our upper arm) and its sheath. The causes of this problem are repeated injury to the biceps tendon, acute severe trauma, and chronic osteochondritis dissecans of the shoulder joint.

Signs and diagnosis
Most dogs that develop biceps tenosynovitis are mature, medium to large breeds; however, small breed dogs also can develop this condition. Intermittent or continuous lameness, which is exacerbated by exercise, is a common clinical sign of biceps tenosynovitis.

Your companion’s veterinarian may find pain upon hyperflexion of the shoulder and extension of the elbow, as this stretches the inflamed biceps tendon. Direct palpation of the tendon near the shoulder joint also may elicit a painful response. Atrophy of the muscles of the affected forelimb is a nonspecific, but common finding.

X-rays of the shoulder may reveal calcium deposits of the biceps tendon and bone spurs that outline the sheath of the biceps tendon. Ultrasound of the biceps tendon may also reveal calcium deposits within the tendon and swelling of the sheath around it.

A sample of joint fluid from the shoulder typically will be compatible with degenerative arthritis. A definitive diagnosis of biceps tenosynovitis is made with arthroscopic examination of the tendon.

Medical therapy for biceps tenosynovitis includes exercise restriction, rehabilitation therapy, weight loss and anti-inflammatory medications. An injection of cortisone can be administered into the joint and can be repeated three weeks after the initial injection. Failure of medical therapy to resolve the clinical signs warrants surgical treatment.

Surgery involves arthroscopic examination of the shoulder to confirm the diagnosis. Next, the tendon is cut from its attachment to the shoulder blade bone. The tendon will heal onto the top of the humerus bone with time, allowing the muscle to regain its function.


Medical management is successful in about 50% of the cases. Surgical treatment usually provides the patient relief of pain and resolution of lameness. Full recovery may take 4 to 6 months after the surgery.

For more information on this subject, speak to the veterinarian who is treating your pet.