Posterior triangle of the neck

Posterior triangle

The posterior triangle forms the posterior compartment of the neck and is separated from the anterior triangle by the sternocleidomastoid muscle.

Boundaries

Anterior: Posterior border of sternocleidomastoid

Posterior: Anterior border of trapezius

Inferior: Middle third of the clavicle

Roof: Skin, superficial fascia & investing layer of deep cervical fascia

Floor: Prevertebral fascia overlying splenius capitis, semispinalis capitis, levator scapulae, scalenus medius & scalenus anterior

The inferior belly of the omohyoid that crosses the triangle divides it into an inferior supraclavicular and superior occipital triangles. 

Clinical significance

The posterior triangle contains level 5 lymph node chains. These include spinal accessory and transverse cervical nodes. Depending on the location of the nodes above or below the accessory nerve, they are sub grouped as level 5a (above) or level 5b (below). 

Boundaries

Anterior: Posterior border of sternocleidomastoid

Posterior: Anterior border of trapezius

Inferior: Middle third of the clavicle

Roof: Skin, superficial fascia & investing layer of deep cervical fascia

Floor: Prevertebral fascia overlying splenius capitis, semispinalis capitis, levator scapulae, scalenus medius & scalenus anterior

The inferior belly of the omohyoid that crosses the triangle divides it into an inferior supraclavicular and superior occipital triangles. 

Clinical significance

The posterior triangle contains level 5 lymph node chains. These include spinal accessory and transverse cervical nodes. Depending on the location of the nodes above or below the accessory nerve, they are sub grouped as level 5a (above) or level 5b (below). 

Posterior triangle

The posterior triangle forms the posterior compartment of the neck and is separated from the anterior triangle by the sternocleidomastoid muscle.

Boundaries

Anterior: Posterior border of sternocleidomastoid

Posterior: Anterior border of trapezius

Inferior: Middle third of the clavicle

Roof: Skin, superficial fascia & investing layer of deep cervical fascia

Floor: Prevertebral fascia overlying splenius capitis, semispinalis capitis, levator scapulae, scalenus medius & scalenus anterior

The inferior belly of the omohyoid that crosses the triangle divides it into an inferior supraclavicular and superior occipital triangles. 

Clinical significance

The posterior triangle contains level 5 lymph node chains. These include spinal accessory and transverse cervical nodes. Depending on the location of the nodes above or below the accessory nerve, they are sub grouped as level 5a (above) or level 5b (below).