gms | German Medical Science

All spinal fusion imposes a compensation overwork of the segment surrounding especially if fusion did not restore the normal anatomy. A long fusion will have a noxious action because of the arm of lever exerted on the subjacent disc. Wear is proportional to the number of requests and thus to time. The scolioses operated in adolescence answer this definition. However the consultations are not invaded by this pathology whereas these faithful patients come regularly in control.

The problems exist nevertheless at the adulthood above and in lower part of the zone of fusion of a scoliosis operated with adolescence. Above the operated zone, the problems are rare because the thoracic spine is not very mobile. There are nevertheless progressive kyphosis with secondary projection of the material. When the instrumentation goes up high, the head plays the part of plague with overwork of the cervico-thoracic junction. In the event of violent traumatism with deceleration one can attend a luxation fracture of this exposed junction.

In lower part of the operated zone, the problems are more frequent because the lumbar spine is mobile. It is possible to take today measures of precaution (ligament, flexible instrumentation….) to avoid a peak of constraint to the jonctional area. The flat back of Harrington is a large provider of degeneration of the intervertebral discs by overwork. This event can also complicate a fusion in good position by only overwork. The situation is sometimes tolerated a long time for finally failing with generally a departure in kyphosis. Instability is transformed then into a disorder of the sagittal balance of the rachis.