New Hybrid Technique Used to Correct Problems From a Previous Cervical Laminectomy

Have you ever heard the expression, Hindsight is 20-20? It means that looking back, we can see perfectly what we should have (or could have) done. Surgeons use this concept to examine patient results and plan better ways to perform procedures. In medical research, a look back at patient records is called a retrospective study.

In this retrospective study, the records of 23 patients of one surgeon were reviewed by two independent surgeons. Each patient had a procedure to reconstruct the cervical spine (neck) following a previously failed surgery.

The reconstructive surgery was called a hybrid decompression. The surgeon removed the disc and the affected cervical bone then fused the segment together. In every case, the surgery was done from the front (anterior approach) of the spine.

More than one vertebral level was treated this way. So the full name of the procedure is multilevel anterior cervical hybrid decompression. In some cases only two levels were decompressed and fused. In others, up to seven levels were involved.

It might help you understand what this procedure was all about by taking a look at the results of the first surgery. The first surgery was a cervical laminectomy. In a laminectomy, a portion of the vertebral bone (the lamina) is removed to take pressure off the spinal cord.

In these 23 patients, the bones collapsed after the laminectomy. Instead of a nice curve in the neck (called lordosis), the bones lined up either too straight or curved in the opposite direction (called kyphosis). The risk of pressure on the spinal cord or spinal nerve roots and possible paralysis is too great to just leave the patient with this postlaminectomy kyphosis.

The reason this particular procedure is so unusual is two-fold. First, removing the rest of the bone (corpectomy) means there’s nothing connecting the spine at that level except soft tissues. The surgeon used a metal plate and screws along the front of the spine to stabilize it. The screws were used to distract the bones and re-establish a more normal alignment of cervical lordosis.

The second unusual aspect of this procedure is that the back side of the vertebrae was not stabilized with any type of fusion materials, plates, or screws. Most patients with this type of problem would have a circumferential fusion — one that goes all the way around front to back. A circumferential approach requires two procedures: one from the front of the spine and one from behind (posterior). The risk of spinal cord damage increases with this type of surgery. In these 23 patients, bone grafts were only placed along the front of the vertebrae to stabilize the spine.

How did everyone do with this type of hybrid decompression and reconstruction? Well, there are several different ways to measure the results. X-rays and CT scans were used to see if the fusion was solid. Before and after signs and symptoms were measured for pain levels; neck and arm pain, weakness, and numbness; bowel and bladder problems; and problems walking.

Everyone had some improvement in their symptoms. More than one-third (39 per cent) had a complete recovery from all pre-operative symptoms. Fusion in at least a neutral position (alignment) was solid for everyone. And the position was maintained for up to 10 years in some patients.

The problem of postlaminectomy cervical kyphosis is a complex one and treatment can be challenging. Although things went well with good results, there were some problems. About one-fourth of the patients developed complications such as difficulty swallowing, graft loosening, infection, pneumonia, and screws backing out.

The authors concluded that this hybrid approach (removing the disc and front side of the vertebral bone) to cervical postlaminectomy kyphosis can be done successfully. Fusion only along the front of the spine can stabilize the spine as well as correct the kyphosis deformity. Long-term results showed significant improvements in all areas. There were some complications but these were decreased from previous studies done by the same surgeon.

But this isn’t the final word on the subject. The authors point out that their sample group was small and no one had the circumferential fusion to compare results with the hybrid and anterior fusion approach.

Future studies are needed with two different groups of similar patients treated with this hybrid procedure compared with the circumferential fusion. Results might be the same or significantly better with one procedure over another. But the only way to know that for sure is to compare them directly.