By: LIVS Staff Surgeon
Bicipital tenosynovitis is an inflammatory condition that affects the origin of the biceps tendon and its tendon sheath or bursa.Anatomy
The biceps tendon originates from the supraglenoid tubercle of the scapula, crosses the shoulder joint and passes through the bicipital groove of the humerus, at which level it widens into the biceps muscle, which attaches to the radial and ulnar tuberosities. The tendon is contained within the bicipital groove by a band of fibrous tissue (transverse humeral retinaculum) that prevents tendon luxation. The biceps’ function is to flex the elbow, extend and stabilize the joint during standing or during the weight-bearing phase of locomotion. Its innervation is attributed to the musculocutaneous nerve.
Inflammation of the biceps tendon can result from acute and chronic trauma (strain), and also from degenerative conditions. An example of chronic repetitive trauma would be excessive jumping activities as seen in agility dogs. Repetitive strain injury may initiate degeneration of the tendon, which leads to micro-tears in the connective tissue, and ultimately leads to shoulder joint instability. Bicipital tenosynovitis usually occurs in middle-aged to older agile canine populations. Clinical Signs
Dogs with bicipital tenosynovitis exhibit an intermittent to constant forelimb lameness that is typically aggravated by exercise. Pain is exhibited on hyperflexion and occasionally hyperextension of the affected shoulder. Muscle atrophy of the forelimb muscle mass is also a common finding. On gait analysis, a weight-bearing lameness is noted, and discomfort may be elicited by direct palpation over the biceps tendon at the humeral groove during shoulder flexion and abduction
A presumptive diagnosis of bicipital tenosynovitis is made by eliciting a thorough history, performing a comprehensive physical exam and by reviewing radiographs. Unfortunately, x-rays are of minimal assistance when the injury is in its acute phase, but may reveal mineralization of the tendon when the condition is chronic. Often the mineralization involves the origin of the bicepital tendon and sclerotic changes of the bicipital groove are common. Ultrasound and MRI are also used to help in diagnosing bicipital shoulder pathology by looking for structural changes of the biceps tendon and rule out infectious, inflammatory and neoplastic causes of joint pain. The gold standard for definitive diagnosis is arthroscopic shoulder examination.
Surgical management of bicipital tenosynovitis is considered in chronic bicipital tenosynovitis if there is no improvement with medical management, rehabilitation and acupuncture. Arthroscopic transection of the bicipital tendon also referred to as tendon release is the ideal surgical option. It consists of completely cutting the biceps tendon at the degenerative biceps groove. Two portals are used, one for the arthroscope (1.9mm for small dogs), (2.4 mm or 2.7mm for medium to large breed dogs), and the second cannula for the instrument (arthroscopic knife). The bicipital tenotomy is performed under endoscopic guidance, and once the tendon is released, it slides within the intertubercular groove. The tendon will adhere to the humerus over time, allowing future normal biceps muscle function. On surgical exploration of the shoulder joint, macroscopic lesions of the tendon and/or sheath that are commonly observed include adhesions, fibrosis, and partial or full tear of the tendon.
Medical management, which includes non-steroidal anti-inflammatory, glucosamine products, and fish oil, combined with weight management and physical therapy will ensure a successful recovery. Additionally, the patient must be strictly rested (leash walks only) for 8-12 weeks with no jumping or rough play allowed.
Arthroscopic tenotomy is the preferred treatment of bicipital tenosynovitis and yields favorable short and long-term success due to the minimal invasive approach. This technique can be considered a reliable and safe method for management of chronic bicipital tendinopathy.
Bicipital tendon partial tear
Arthroscopic bicipital tenotomy