CERVICAL SURFACE ANATOMY

Professor Con Yiannikas

Anatomical Landmarks

Cervical Dystonia

Anatomy

Vertebral Levels

The Interscalene Groove

Cervical Dystonia

Anatomy

• The interscalene groove lies immediately behind the lateral border of the clavicular head of the sternocleidomastoid muscle at the level of the cricoid cartilage (C6)

• Approximately 1cm above the separation of the sternal and clavicular heads of the sternocleidomastoid muscle.

Structures to Avoid

Cervical Dystonia

Anatomy

The BP lies inferior to a line from the posterior margin of the sternomastoid at the level of the cricoid cartilage to the midpoint of the clavicle

Brachial Plexus

Structures to Avoid

Cervical Dystonia

Anatomy

Interscalene Groove and Plexus

Structures to Avoid

Cervical Dystonia

Anatomy

• Accessory nerve

  • Lies on LS, enters 1cm cranial to EP posterior border of SCM and runs on line to between middle and lower third of trapezius.

• ​Should inject splenius and levator over 1cm above EP

• Cervical plexus cutaneous branches

  • Mid point of posterior border​

Nerves in Posterior Triangle

Structures to Avoid

Cervical Dystonia

Anatomy

Accessory nerve

​Inject levator above this point

Cervical plexus

Middle and lower third of Trapezius

Nerves in Posterior Triangle

Landmarks

Structures to Avoid

Cervical Dystonia

Anatomy

• Carotid artery

  • Midpoint anterior border of SCM

• ​Vertebral artery
  • Occipital bone or C2 towards midline is safe

• Occipital artery

  • Avoid apex of posterior triangle

Arteries

Structures to Avoid

Cervical Dystonia

Anatomy

Vertebral Artery

Landmarks

Splenius Capitis/Cervicis

Cervical Dystonia

Anatomy

1. Midway between the inion and mastoid process
2. From the same attachment forward is SCM
3. Runs obliquely to spinal processes of C7 to T3
4. Cervicis runs lateral border and underneath capitus  anterior to levator scapulae.

Surface Anatomy

Splenius EMG

Cervical Dystonia

Anatomy

¿Splenius?

Cervical Dystonia

 Surface Anatomy

Longissimus Capitis

Cervical Dystonia

 Surface Anatomy

Surface Anatomy

• Inserts into mastoid and occipital bone, and is underneath splenius capitis and over the lateral border of semispinalis capitis.

• It is the layer below splenius capitus and medial to it and underneath it is the lateral border is semispinalis capitus.
  

Levator Scapulae

Cervical Dystonia

 Surface Anatomy

Posterior Triangle Surface Anatomy

• Runs from C1-4

• Inject in midline of posterior triangle above 2cm above EP (midpoint of SCM) and 3-4 cm below mastoid

• Below splenius capitus

Levator Scapulae

Cervical Dystonia

Anatomy

Posterior Surface Anatomy

1. Line from acromium to midline and inferior
2. Feel the edge of the spine
3. Above and below is infra and supraspinatus fossae
4. Follow spine to midline (T3 level)
5. Above that along the medial border

6. Line obliquely from there to transverse process of C1-4 (below and anterior to splenius capitus)

Levator Scapulae EMG

Cervical Dystonia

Anatomy

Lateral neck

Scapula

Scalenes

Cervical Dystonia

Anatomy

• The scalenus anterior and medius muscles lie immediately anterior and posterior to the plexus in the interscalene region and then insert onto the first rib.

• The upper, middle and lower trunks are enclosed within the interscalene fascial sheath as they emerge between the scalene muscles.

Scalenus Medius

Cervical Dystonia

 Surface Anatomy

Surface Anatomy

Scalenus medius is behind and above a line from the posterior margin of the sternomastoid at the level of the cricoid cartilage to the midpoint of the clavicle.

Scalenes

Cervical Dystonia

Anatomy

Scalenes EMG

Cervical Dystonia

Anatomy

Sub-Occipital Triangle

Cervical Dystonia

Anatomy

Splenius Capitis

Semispinalis

Rectus Minor Major

Obliquus Superior

Obliquus Inferior

• Triangle between C1 transverse process (below and behind mastoid), C2 and occiput.

• Pass through Trapezius, Splenius capitus (more lateral) and semispinalis capitus (more medial) to reach it.

Sub-Occipital Triangle

Cervical Dystonia

Anatomy

• The C2 level is a plane 2.5 cm below the mastoid process

Rectus Capitis Major

Obliquus Capitis

Obliquus Capitis Inferior

• Midway between the posterior border of the sternocleidomastoid and the dorsal midline.

• Depth of 3.0-3.5 cm.