Editors

JuhaKukkonen

KaisaLehtimäki

AnssiRyösä

Biceps Tendon Disorders and Injuries

Anterior shoulder pain is a common symptom often associated with abnormal strain. It may sometimes be due to tendinosis (degeneration) of the proximal (long head of the) biceps tendon.
Proximal biceps rupture may appear either without or in association with injury. The diagnosis is clinical and the treatment in either case conservative.
Rupture of the distal head of the biceps must be identified as its treatment is usually operative.

The biceps muscle of the arm (m. biceps brachii) consists of a short head and a long head (picture 1).
The biceps is a strong supinator and weak flexor of the forearm.

Degenerative changes of the proximal (long head of the) biceps tendon are quite commonly seen in imaging, but their true causal connection with the symptoms often remains unclear 1. According to clinical experience, the proximal short head of the biceps tendon shows no tendinopathy causing clinical symptoms and no ruptures.
- In association with symptomatic rotator cuff rupture, changes are seen in the long head of the biceps tendon in as many as 82% of cases 6.
Injuries of the distal head of the biceps are uncommon, with an incidence of 10/100 000 2.

Degeneration typically causes pain anteriorly to the shoulder joint, possibly radiating down along the biceps.
Pain associated with snapping or slipping away may suggest instability of the long head tendon, where the tendon slips away from its bony groove.
A rupture may be preceded by sudden strain on the biceps but it may occur without any precipitating factor.
- The patient may feel sudden pain, sometimes snapping, in the shoulder region.
- There may be a subcutaneous haematoma anteriorly on the upper arm.
The rupture is palpable as "Popeye biceps", and in a slim patient, it can also be seen (picture F2, Video 1). This is due to distal retraction of the muscle mass.

Exercise-induced pain in the biceps is a characteristic symptom of tendinitis.
- The symptom did not start from trauma or otherwise suddenly.
- In the hook test (picture F3, video Rupture of the Proximal Long Head of the Biceps Muscle), the tendon is palpable in its normal place but usually tender.
The rupture is typically caused by an external straightening force applied to the elbow joint with the forearm flexed in supination. Lifting a heavy object may sometimes be sufficient to cause such a rupture.
The rupture will cause sudden pain in the antecubital fossa.
There may be a subcutaneous haematoma on the antecubital fossa or proximally on the forearm.
There may be proximal retraction of the biceps muscle mass (picture F2).
The forearm supination strength is usually reduced.

If a patient has symptoms in the shoulder area, the possibility of frozen shoulder Frozen Shoulder or rotator cuff disorders Non-Traumatic Tendon Problems of the Shoulder should be considered.
If traumatic rupture of the proximal biceps tendon is suspected, concomitant rotator cuff rupture should be excluded Traumatic Tendon Problems of the Shoulder.

In most cases, imaging is not necessary.
If the diagnosis of proximal tendon rupture is not clear, the primary differential diagnostic examination is an X-ray.
- Ultrasonography will provide little added value for diagnosis or for choosing the line of treatment. If the decision is nevertheless made to perform ultrasonography due to regional factors or local guidelines, an X-ray should be taken first anyway.
If the history and symptoms are consistent with a distal tendon rupture but the clinical finding is not clear, there may be a partial rupture, and the primary imaging method is MRI 3 4.

The primary mode of treatment of degeneration of the proximal biceps tendon is conservative. Typically, the patient has been involved in work or hobbies straining the anterior shoulder, with poor scapular support.
- Guidance on exercises improving shoulder girdle position and movement control by a physiotherapist
- Paying attention to strain from work and work ergonomics
A proximal tendon rupture requires no treatment, and the patient can use his/her arm freely. A distally retracted biceps may be painful and keep cramping for a few weeks but the symptoms will subside with time. There will be no significant residual reduction of strength either.
If the symptom is suspected of being caused by tendinitis/tendinosis or instability of the proximal biceps and it cannot be successfully treated conservatively within 3-6 months, operative treatment can be considered. If so, the diagnosis should be specified further by MRI of the shoulder, referring the patient to specialized care as necessary.
Distal tendon ruptures are usually treated operatively.
- Urgent (1-7 days) referral for specialized care

Panico L, Roy T, Namdari S. Long Head of the Biceps Tendon Ruptures: Biomechanics, Clinical Ramifications, and Management. JBJS Rev 2021;9(10): [PubMed]
Launonen AP, Huttunen TT, Lepola V, et al. Distal Biceps Tendon Rupture Surgery: Changing Incidence in Finnish and Swedish Men Between 1997 and 2016. J Hand Surg Am 2020;45(11):1022-1028 [PubMed]
Lobo Lda G, Fessell DP, Miller BS, et al. The role of sonography in differentiating full versus partial distal biceps tendon tears: correlation with surgical findings. AJR Am J Roentgenol 2013;200(1):158-62 [PubMed]
Festa A, Mulieri PJ, Newman JS, et al. Effectiveness of magnetic resonance imaging in detecting partial and complete distal biceps tendon rupture. J Hand Surg Am 2010;35(1):77-83 [PubMed]
O'Driscoll SW, Goncalves LB, Dietz P. The hook test for distal biceps tendon avulsion. Am J Sports Med 2007;35(11):1865-9 [PubMed]
Murthi AM, Vosburgh CL, Neviaser TJ. The incidence of pathologic changes of the long head of the biceps tendon. J Shoulder Elbow Surg 2000;9(5):382-5 [PubMed]