If you look at the average person from the side as they look forward, the neck appears straight up and down. But, in fact, there is a backward curve called lordosis that helps keep the head and neck in perfect alignment. Injury such as you described for your grandson can change this head-neck relationship causing a condition referred to as swan neck deformity.
Ligamentous damage causing laxity looseness) can lead to instability and even dislocation of the cranium (head or C0) on the first cervical vertebra (C1). This is also known as atlantoaxial dislocation (again, referring to the abnormal movement of the head (skull) over the first cervical vertebra).
As a result of these cervical spine changes, the upper portion of the neck becomes kyphotic (develops a forward curve of the neck opposite of lordosis). The lower portion of the cervical spine then compensates by becoming hyperlordotic. The resulting changes in alignment are referred to as a swan neck deformity.
From the side view, the neck looks like the curve of a swan’s neck. These changes occur as the head, neck, body complex attempts to keep the head balanced over the neck and the eyes on a straight plane to protect vision. A similar curvature and reverse curvature of the fingers can occur in people with severe rheumatoid arthritis of the hands. Swan neck deformity of the hands is far more common than the swan neck deformity of the head and neck.
Surgery can be done to fuse the head and neck (C0-C2) and stop the abnormal movement of the atlantoaxial junction. Recently, a report was published for a series of patients (total of 68 people ages four to 68) who had this procedure under the care of one single surgeon. The goal was to see (and report on) changes in overall neck alignment with this procedure. X-rays viewing the cranium (skull) and neck and change in function and neurologic status were used to measure before and after results.
The surgery was successful for all but two patients who continued to have painful and neurologic symptoms that continued to get worse over time. In all the other patients, posterior fusion of the upper cervical spine actually resulted in the body auto-correcting the lower (subaxial) cervical spine (below the level of the fusion). This was a hoped for but uncertain favorable outcome.
The authors concluded that reversal of subaxial cervical alignment does occur in patients of all ages who have atlantoaxial dislocation that is stabilized with posterior fusion of C0 to C2. The amount of change in the lower cervical spine (C2-C7) was significantly and directly linked with the amount of change at the C0-C2 levels.
This was the first study to report on the effect of such a correction in patients with this complex swan neck deformity. The type of fusion hardware used (screw and plate system) has been approved in China but not by the United States Food and Drug Administration (FDA). This may be why you were unable to find more information about thisp problem. We hope this information helps you.