Costoclavicular ligament

At a glance

English

Costoclavicular ligament

Latin (TA2)

Ligamentum costoclaviculare

System

Ligament

Region

Upper limb

Side

Paired, left and right

About the costoclavicular ligament

The sternoclavicular joint gets little stability from its bony surfaces, and its chief binding is a ligament that does not cross the joint at all. The costoclavicular ligament (rhomboid ligament, Halsted's ligament) lies just lateral to the joint, between the underside of the clavicle and the top of the first rib. It is short, flat and diamond-shaped, and is the strongest of the ligaments that hold the clavicle to the trunk.

Its lower end is attached to the upper surface of the first rib and its costal cartilage, near their junction. From there the fibres climb upwards, backwards and laterally to the costal tuberosity (impression for the costoclavicular ligament), a rough, sometimes grooved area on the underside of the medial end of the clavicle. The ligament usually has two layers, an anterior one running upwards and laterally and a posterior one running upwards and medially, which cross each other, with a bursa sometimes between them. In front of it lies the tendon of origin of subclavius; behind it lies the subclavian vein on its way to join the internal jugular.

The ligament acts as the pivot of the sternoclavicular joint. When the shoulder is shrugged the lateral end of the clavicle rises and the medial end glides down around this point, and when the shoulder is pulled forwards or backwards the clavicle swings about it. Its crossing layers restrict excessive elevation of the medial end and both forward and backward displacement.

Because of this pivot role the ligament explains why the medial clavicle rarely dislocates. Its close relation to the subclavian vein and the space between clavicle and first rib (the costoclavicular space) is relevant in thoracic outlet syndrome, where vessels or nerves of the upper limb are compressed. Regional anaesthetists use the same space for a costoclavicular brachial plexus block.

Attachments and function

Attaches from

The upper surface of the first rib and its costal cartilage near their junction.

Attaches to

The rough impression (costal tuberosity) under the clavicle's inner end.

Function

Anchors the medial clavicle to the first rib, forms the pivot for movements at the sternoclavicular joint and limits elevation and forward or backward displacement of the clavicle.

Nerve supply

Branches of the nerve to subclavius and the medial supraclavicular nerve.

Blood supply

Branches of the internal thoracic and suprascapular arteries.