C5C6

C5C6, typically written with a dash as C5-C6, designates the cervical vertebral level between the fifth and sixth cervical vertebrae in the human spine. This segment includes the C5 and C6 vertebrae themselves, the intervertebral disc separating them, the adjacent facet joints, and the exiting spinal nerve roots associated with those levels.

Anatomically, the C5-C6 region lies in the mid to lower portion of the neck. The intervertebral disc between C5 and C6 provides cushioning and allows flexion, extension, and rotation of the neck. The facet joints at this level help stabilize the cervical spine. The C5 and C6 nerve roots exit the spinal canal via the neural foramina at this level and contribute to upper limb innervation, with C5 primarily supporting shoulder function and C6 contributing to elbow flexion and wrist extension.

Clinically, the C5-C6 level is a common site of cervical degenerative disease and disc herniation. Pathology at this level can cause cervical radiculopathy, presenting as neck pain with radiating pain into the shoulder, arm, or forearm, and may include sensory changes or weakness in C5- or C6-derivative muscles. A C6 radiculopathy, for example, may affect the biceps and wrist extensors and present with a diminished biceps reflex.

Diagnosis typically involves magnetic resonance imaging (MRI) to visualize disc herniation, foraminal narrowing, or nerve compression, supplemented by X-rays or CT if bone detail is required. Treatment ranges from conservative measures—physical therapy, nonsteroidal anti-inflammatory drugs, and activity modification—to surgical intervention such as anterior cervical discectomy and fusion (ACDF) or cervical disc replacement when conservative therapy fails or neurologic deficits progress.