Review Question - QID 2206

Congenital kyphosis often requires in situ arthrodesis secondary to the rapid growth of the spine in the first year of life. Congenital block vertebrae are the least likely to progress and would not require early surgical intervention.

Congenital kyphosis occurs secondary to a genetic mistake during the 6th-8th week of gestation and is due to either failure of formation or failure of segmentation. Failure of segmentation occurs when two or more vertebrae fail to separate. When segmentation defects (type II) lead to unilateral bar formation, there can be rapidly progressive spinal deformity which may require early surgical treatment. With progressive kyphotic deformity, in situ fusion is often recommended for type I deformity. Epiphysiodesis is utilized when adequate posterior fusion cannot be obtained, and anterior surgery is reserved for those with evidence of neurologic compression or deformities exceeding 50 degrees. There is no role for bracing in the management of congenital kyphosis.

Winter et al. reviewed the results of spinal arthrodesis for congenital spinal deformity in 49 patients younger than five years old. They report that for patients with congenital kyphosis, posterior arthrodesis was highly effective, giving better eventual correction than when both anterior and posterior arthrodesis was done. They concluded that posterior arthrodesis is a reliable surgical intervention for patients with congenital kyphosis.

Pruszczynski et al. reported on two patients with skeletal dysplasia and thoracic kyphosis who sustained spinal cord injury after lower extremity surgery. They found that in these two patients with kyphotic curves exceeding 75 degrees, the mean arterial pressure decreased below 50mmHg with subsequent paraplegia. They concluded that patients with hyperkyphotic curves undergoing extremity surgery may be at risk for spinal cord injury and an MRI of the spine may be recommended, along with maintaining MAP at a safe level.

Illustration A is the depiction of failure of formation and failure of segmentation for congenital kyphosis.

Incorrect Answers:
Answers 1, 2, and 3: 50-degree curve, failure of formation (type I deformity), and congenital unilateral bar formation (type II deformity) have a high likelihood of progression and benefit from early surgical intervention.
Answer 4: The presence of neurological weakness necessitates early surgical intervention.