Craniovertebral Anomalies
The craniovertebral junction (CVJ), comprises the occiput, the foramen magnum, along with the first two cervical vertebrae. It also includes the medulla oblongata and the upper cervical spine. CVJ anomalies might be congenital or acquired or due to Rheumatoid arthritis. CVJ anomalies that reduce the volume of posterior cranial fossa can lead to Chiari malformations. Craniovertebral anomalies lead to a range of symptoms that are secondary to neural compression, malformation of bone and manifest instability.
Upper Cervical Spine Anomalies
The abnormal conditions of head & upper neck are called upper cervical anomalies, craniovertebral junction (CVJ) anomalies, or craniocervical anomalies. They are an array of the brain and spinal cord disorders that happen at the base of the skull and the upper part of the neck. An injury or other diseases can also cause upper cervical anomalies; sometimes you may be born with it, which is known as congenital anomalies (present at birth).
The following are congenital and acquired anomalies of the upper cervical spine. These conditions are also termed as craniovertebral junction (CVJ) abnormalities or craniocervical disorders that occur at the bottom of the skull and at the upper cervical spine (your neck).
Congenital Anomalies
Klippel-Feil Malformation
Klippel-Feil syndrome is a spinal disorder defined by the abnormal joining of two or more bones in the neck (cervical vertebrae). Klippel-Feil syndrome is also associated with some other spinal disorders, which include scoliosis and atlantoaxial instability.
Treatment: For an orthopaedic spine surgeon, the indications for surgical treatment of Klippel-Feil syndrome is associated with the volume of deformity and its progression with time. The treatment is based on symptomatic and surgery is intended to relieve craniocervical instability and to bind the spinal cord & to correct scoliosis. Physical therapy is also helpful.
Atlantoaxial Instability
Atlantoaxial instability (AAI) is a disorder characterized by excessive movement caused by a bone or ligament abnormality between the cervical bones called atlas (C1) and axis (C2).
Treatment: For people with AAI, the treatment aims to protect your spinal cord, stabilize it, decompress the neural tissue, and to reduce spinal deformity. If the injury is entirely ligamentous and not likely to heal, they are treated with posterior C1-2 fusion. Atlantoaxial instability is secondary to basilar invagination which is an acquired anomaly.
Atlas Hypoplasia: Atlas hypoplasia appears when you are born with an underdeveloped atlas, the top bone of your cervical spine (C1).
Treatment: The treatment includes, a posterior C1 ring laminectomy along with autogenous iliac bone graft and occipitoatlanto-axial fusion with the help of wire fixation is performed.
Os odontoideum:
Os odontoideum (OO) anomaly is very rare and occurs to the second cervical vertebrae defined by the separation of a part of the odontoid process from the body of the axis.
Treatment: Os odontoideum can be addressed through several surgical options such as Posterior atlantoaxial onlay fusion, Posterior atlantoaxial wiring & fusion and Posterior occipitocervical wiring & fusion.
Syringomyelia:
Syringomyelia is a disorder in which a cyst or cavity is formed within the spinal cord. This cyst is also called a syrinx which can extend and expand over time, destroying the structure of your spinal cord.
Treatment:
If syringomyelia causes severe signs and symptoms that interfere with your life, an orthopaedic spine doctor will likely recommend surgery. The surgical goal is to eliminate pressure on your spinal cord and to restore the natural flow of cerebrospinal fluid.
Achondroplasia:
Achondroplasia is a common bone growth disorder that prevents the growth of cartilage to bone. It causes dwarfism, limited range of motion at the elbows, shorter limbs, large head size and short stature.
Treatment: Spinal fusion surgery to stabilize your spine. Spinal decompression surgery to relieve pressure on the spinal cord or nerve roots. Guided-growth surgery or osteotomy to correct abnormal growth of the bones. Limb-lengthening surgical procedure is performed for this condition.
The Common Acquired Anomalies
Cervical Rheumatoid Arthritis:
Rheumatoid arthritis (RA) is an autoimmune disease that can damage your joints throughout the body. It can attack the atlantoaxial joint in your upper neck between the top two bones in your spine; the atlas, C1, and the axis, C2.
Treatment: Treatment largely depends on the effects on the spinal cord by the C1-C2 misalignment. If the spinal cord is not compressed, an orthopaedic spine doctor suggests for a cervical collar or nerve blockers for pain management. If the spinal cord is damaged, a decompression surgery and fusion of the C1 and C2 bones is done to restore the stability to your upper spine.
Degenerative Arthrosis or Spinal Osteoarthritis:
Spinal osteoarthritis is a condition that breaks the cartilage of the joints and discs in your neck and lower back. It disrupts the atlantoaxial joint. It is also called degenerative joint arthritis or spondylosis. Sometimes, osteoarthritis results in spurs that creates pressure on the spinal nerves leading to weakness and pain in your arms or legs.
Treatment: Both surgical and non-surgical treatment is available for spinal osteoarthritis such as physical therapy, pain relief medication, corticosteroid injection, acupuncture etc. spinal fusion is an effective surgical treatment for degenerative arthrosis.
Synovial Cysts at C1-C2:
Synovial cysts are considered as an extradural mass in the upper cervical spine. They are benign (non-cancerous) fluid-filled sacs that grow in your spinal facet joints due to joint degeneration.
Treatment: Posterior fusion, along with excision of the cyst directly might be the optimum treatment for synovial cyst at the C1-C2 junction in a patient having atlantoaxial subluxation.
Pseudogout:
Pseudogout occurs when the calcium pyrophosphate dihydrate crystals build up in the joints. The crystals might cause inflammation and damages joints. Pseudogout can result in crowned dens syndrome in the upper cervical spine, that happens when the crystal deposits surround the dens in the axis (C2).
Treatment: To relieve pressure and pain in the affected joints, an orthopaedic doctor performs a joint aspiration to remove fluid and some crystals from the joint. Nonsteroidal anti-inflammatory drugs and corticosteroids also commonly used to treat pseudogout.
If you or your family members have any problems with your cervical spine, call Dr Surya Prakash, one of the best spine surgeons in Hyderabad. He has more than 20 years of experience in handling Cervical Spine & Craniovertebral Anomalies.
