A 13-year-old male with lower extremity weakness | Sub-classification: Spine
A 13-year-old male presents with a six month history of difficulty walking. There is no history of trauma, malignancy, or other medical problems. He states that his legs feel “tight” and that the left leg is numb. He does not endorse upper extremity problems or incontinence of bowel or bladder.
Cranial nerves II-XII are intact
DTRs – 3+ upper and lower extremities
+ Clonus left lower extremity
Decreased sensation in left lower extremity
Mildly spastic gait
Question 1: The imaging demonstrates a severe case of os odontoideum. Based on the patients young age and lack of any trauma history the likely cause of the malformation is congenital, although the origin (trauma vs congenital nonunion) of os odontoideum in the broader population is debatable. Laxity of ligamentous structures can be seen in Ehler Danlos patients. Inflammatory pannus can be seen in patients with Rheumatoid arthritis.
Question 2: The patient needs reduction, decompression and fixation. The next step should be traction, likely using a halo ring in preparation for later halo placement. Posterior occipitocervical fusion and decompression is required given the amount of basilar invagination. A biopsy will not be helpful because imaging does not show an obvious tumor and this will not improve the neural compression. An anterior decompression will not result in stabilization of the spine, although an anterior decompression followed by a posterior fusion is an option. Traction with just C1-2 fusion is unlikely to be stable due to the degree of basilar invagination. External orthosis will not remove neural compression.
Question 3: A CT-angiogram can help to demonstrate the location of the vertebral arteries and any associated abnormality since a posterior OC fusion is being planned. The other options would not change the management of the patient.
Please subit your answers to see the case explanation.
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SANS Pediatric Module