Congenital Cervical Hemivertebrae and Block Vertebrae in a 43-Year-Old Male.

Congenital deformities of the spine are a consequence of anomalous vertebral development in the embryo and may be identified at birth or remain unnoticed until adulthood. Minor bony malformations of all types occur in up to 12% of the general population and are usually not apparent. In contrast, congenital spinal malformations that result in progressive spinal deformity are relatively rare. Klippel-Feil syndrome is a complex heterogeneous entity that results in cervical vertebral fusion and sometimes can occur associated to hemivertebra. We present a case of a 43-year-old male who presented to the emergency department after a fall. The patient had severe cervicalgia and generalized loss of active movement and sensation on his limbs. On physical examination, the patient presented reduced cervical range of motion and tetraplegia. Cervical magnetic resonance imaging revealed complete atlanto-occipital assimilation, left C3 hemivertebra with partial fusion in the right lateral portion of C2 and C4. Finally, there was a C5-C6 fusion. Surgical cervical stabilization was attempted but the procedure was aborted due to lack of space for placing the anterior plate safely. During hospitalization, the patient wore a cervical collar and started a rehabilitation program including muscle strengthening, balance, and gait training. The rehabilitation treatment led to a favorable clinical evolution. At discharge, the patient maintained a slight deficit of strength in his left upper and lower extremities, but he was functionally autonomous and was able to walk with a walker.