Monday, May 3, 2021

Congenital Spine Dislocation               5-3-2021

Congenital dislocation of the spine (CDS) is a rare congenital malformation due to failure of the spine and the spinal cord to develop at a single spinal level. 

The patient may be completely neurologically intact or, in severe cases, may not have any muscle function or sensation below the level of the dislocation.

It is potentially the most serious form of congenital kyphosis or scoliosis with an abrupt single-level displacement of the spinal canal.  See the below x-rays of an 18 month old female, who was noticed to have a “bump” on her back, at the red arrow.  

She was moving her legs normally and was felt to have normal sensation in her legs.  The red arrow points to the T12 vertebra which does not sit under the T11 vertebra (orange arrow).

The right side X-ray shows how the upper spine (thick green line) does not line up with the lower spine (thick red line)

When lying down the T12 vertebra does not move under the T11 vertebra… is dislocated.

On the below CT scan cuts the red arrows point to the dislocation, with T12 sitting too far back.

The below MRI cut nicely shows how the spinal cord is draped over the posterior T12 vertebra.  It is easy to see if the dislocation gets worse the spinal cord will get more compressed and deformed, which would then cause problems with muscle function and sensation in the legs and cause bowel and bladder incontinence (inability to control).

To correct the dislocation, the T12 vertebra needed to be completely removed, and once it was the spine was very mobile and allows T11 get appropriately lined up with the L1 vertebra.  Because there was a space between T11 and L1 a cage (yellow arrows) was put between them to add to stability and put the spinal cord at the correct length. 

Four pedicle screws were placed above and below the removed T12 vertebra and were locked down.  To make sure this area heals solidly, and permanently a bone graft was placed in the cage in the front and also in the back of the spine.

In the below slide the patient is now 6 weeks after surgery.  It is easy to see the improvement of the spine alignment back to normal.  Because the bone is soft at this age we kept her in a brace for 6 months to protect the surgery.

Here she is now 8 year out after surgery.  She has normal spinal alignment and normal function of her spinal cord.  Her long-term prognosis is for a normal life.


No comments:

Post a Comment