QS Study

Suboccipital Triangle is a muscular space that lies deep in the suboccipital region. It is a region of the neck bounded by the following three muscles of the suboccipital group of muscles:

  • Rectus capitis posterior major – above and medially
  • Obliquus capitis superior – above and laterally
  • Obliquus capitis inferior – below and laterally

Steps of dissection

(A) Skin incision:

  • A longitudinal incision along the midline from the external occipital protuberance to a point midway between the vertebra prominence & external occipital protuberance.
  • A transverse incision from the upper end of 1st incision which extends laterally for about 7.5 cm.
  • Another transverse incision from the lower end of the 1st incision which extends laterally for about 7.5 cm.

Then the flap of the skin is reflected laterally.

(B) Removal of superficial fascia:

The fascia has to be removed avoiding injury to the subcutaneous structure.

Then trapezius and splenius capitis muscles are removed.

(C) Removal of deep fascia:

The investing layer of cervical fascia has to be removed from the triangle & the surrounding muscles.

suboccipital triangle 1

Fig: Suboccipital Triangle

Boundaries

(a) Superomedially: Rectus capitis posterior major muscle.

(b) Superolateral: Superior oblique muscle.

(c) Inferiorly: Inferior oblique muscle.

(d) Roof:

  • Medially: Dense fibrous tissue covered by semispinalis capitis.
  • Laterally: Longissimus capitis.

(e) Floor:

  1. Posterior arch of the atlas.
  2. Posterior atlantooccipital membrane.

Contents

  • 3rd Part of the vertebral artery.
  • Dorsal ramus of nerve C1.
  • Suboccipital plexus of veins.
  • Tough fibrous tissue & fat.

The purpose of these muscles is to provide a fine motor function in movements of the head.

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