[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Spine](https://durgical.com/en/anatomy/region/spine/) › C3–C4 disc [Joints and ligaments](https://durgical.com/en/anatomy/system/joints-and-ligaments/) · [Spine](https://durgical.com/en/anatomy/region/spine/) # C3–C4 disc The C3-C4 disc is the cushion between the C3 and C4 neck vertebrae; it absorbs load and lets the neck bend and turn. Official name: C3-C4 [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=spine&select=disc_c3_c4&side=r) Opens in the Durgical app, no sign-up needed. ## What it is The cushion between C3 and C4: a tough outer ring of fibres (annulus fibrosus) around a soft centre. ## What it does Absorbs load and lets the neck bend and turn. [C5-C6](https://durgical.com/en/anatomy/c5-c6/) is the most mobile and most worn neck level. ## Key points - C4 root picture: pain and numbness over the base of the neck and the top of the shoulder (cape area), with no reliable reflex or single muscle to test - The [diaphragm](https://durgical.com/en/anatomy/diaphragm/) is driven from cord segments C3–C5 («C3, 4, 5 keeps the diaphragm alive»), so a cord injury around this height can affect breathing - In older adults, once the lower levels have stiffened, C3–C4 is often reported as a site of cord compression (cervical myelopathy) ## Key facts **Where** Between C3 and C4 bodies; taller in front (cervical lordosis); flanked by uncovertebral joints **Attaches** Annulus fibrosus anchored to the [endplates](https://durgical.com/en/anatomy/vertebral-endplates/) and ring apophyses of C3 and C4; anterior and posterior longitudinal ligaments **Function** Absorbs and spreads load; posterolateral herniation usually compresses the C4 root ## Relations **In front** [Longus colli](https://durgical.com/en/anatomy/longus-colli-muscle/) and prevertebral fascia; in front, the lower [pharynx](https://durgical.com/en/anatomy/pharynx/) and the larynx, with the hyoid and the upper border of the [thyroid cartilage](https://durgical.com/en/anatomy/thyroid-cartilage/) near this level **Behind** [Posterior longitudinal ligament](https://durgical.com/en/anatomy/posterior-longitudinal-ligament/), epidural veins, the dural sac and the [spinal cord](https://durgical.com/en/anatomy/spinal-cord/) **Lateral** Uncovertebral joints, the [vertebral artery](https://durgical.com/en/anatomy/vertebral-artery/) in the transverse foramina and the C4 root leaving through the C3–C4 foramen ## How to find it From the front, the C3–C4 disc lies near the hyoid and the upper edge of the thyroid cartilage. From behind it is between the [C3 vertebra](https://durgical.com/en/anatomy/cervical-vertebrae/) and [C4 vertebra](https://durgical.com/en/anatomy/c4/) spinous processes, which are short and hard to tell apart under the neck muscles. ## Examination - Hoffmann sign: flicking the nail of the middle finger makes the thumb and index finger flex; a positive sign suggests an upper motor neuron problem such as cord compression in the neck - Lhermitte sign: an electric feeling down the [spine](https://durgical.com/en/anatomy/region/spine/) or into the limbs when the neck bends forward; it points to a problem in the cord, such as compression ## On imaging Lateral cervical radiographs show disc height and osteophytes; after trauma, a widened soft-tissue shadow in front of the upper cervical spine suggests haematoma. MRI is the test of choice: sagittal T2 shows the disc pressing on the cord and, in myelopathy, high signal inside the cord. In older people with spondylosis, a hyperextension injury may leave a normal CT, so MRI looks for cord damage. ## Common problems - Herniation pressing on the [C6 nerve root](https://durgical.com/en/anatomy/c6-spine-and-pelvis/): neck pain and pain, numbness or weakness down the arm into the thumb side of the hand. - Degeneration with bone spurs, which can narrow the canal and press on the spinal cord (myelopathy: clumsy hands, unsteady walking). ## How it is diagnosed Exam of arm strength, reflexes and feeling, plus signs of cord pressure. MRI shows the disc, nerve roots and cord. ## Treatment - Most arm pain from a disc improves with time, physical therapy, medicine and sometimes an injection. - Lasting arm pain, weakness or cord pressure: anterior cervical discectomy and fusion (ACDF), or disc replacement in selected patients. ## Clinical notes - The anterior approach at C3–C4 passes close to the [superior thyroid artery](https://durgical.com/en/anatomy/superior-thyroid-artery/) and the [superior laryngeal nerve](https://durgical.com/en/anatomy/superior-laryngeal-nerve/); injury to its external branch can lower the voice's range - C4 shoulder-top pain is easily confused with a [trapezius](https://durgical.com/en/anatomy/trapezius-muscle/) strain or with shoulder disease - After anterior cervical surgery, a collection of blood in the space in front of the spine can squeeze the airway within hours; the risk is higher with upper and multilevel operations, so breathing and neck swelling are watched closely ## Development Like every disc, it forms from mesenchyme between the vertebral bodies; remnants of the notochord persist in its centre and contribute to the nucleus pulposus, while the rest of the notochord disappears inside the bodies. ## Test yourself Think of the answer, then tap the question to see it. ## What is the clinical picture of the C4 root compressed by a C3–C4 disc herniation? Pain and numbness over the base of the neck and the top of the shoulder (cape area), with no reliable reflex or single muscle to test. ## How is the Hoffmann sign elicited, and what does it suggest in cord compression at C3–C4? Flicking the nail of the middle finger makes the thumb and index finger flex; it suggests an upper motor neuron problem such as cervical cord compression. ## Which nerve is at risk in an anterior approach to the C3–C4 disc, and what does its injury cause? The superior laryngeal nerve, near the superior thyroid artery; injury to its external branch can lower the voice's range. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/anatomy/c3-c4/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** discus intervertebralis C3-C4 TA2 1684 **Official Spanish (DeCS)** Disco C3-C4 DeCS D007403 **English (TA2)** C3-C4 **Also called** fibrous ring · fibrocartilago intervertebralis ## Related - [C3–C4 nucleus](https://durgical.com/en/anatomy/c3-c4-spine-and-pelvis/) - [C3 vertebra](https://durgical.com/en/anatomy/cervical-vertebrae/) - [C4 vertebra](https://durgical.com/en/anatomy/c4/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=7567); [Anatomy, Back, Intervertebral Discs](https://www.ncbi.nlm.nih.gov/books/NBK470583/); [7.5 Embryonic Development of the Axial Skeleton](https://openstax.org/books/anatomy-and-physiology-2e/pages/7-5-embryonic-development-of-the-axial-skeleton) (OpenStax (Rice University), 2022) · adapted, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/c3-c4/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/c3-c4/