Sprengel's deformity- approx. Includes C1-C2 hypermobility and instability, basilar invagination, and cervical stenosis at or below the instability. Chiari I malformation, cervical dysraphism or diastematomyelia, syringomyelia and intracranial tumors have been reported. Flexion and extension occurs at C1-C2 thereby becoming unstable. Single open space between two fused segments.
Symptoms are related to the hypermobility occurring at the open segments.
Can either have frank instability or osteoarthritis. Mechanical symptoms due to joint irritation. Nuerologic symptoms due to root irritation or spinal cord compression. Major neurologic sequela can include death or quadriplegia following minor trauma in high-risk patients. Minimally involved patients lead normal lives with only minor restrictions.