[Vertebral body replacement system Synex in unstable burst fractures of the thoracic and lumbar spine--a retrospective study with 30 patients].

OBJECTIVES: Retrospective analysis of the vertebral body replacement system Synex in unstable burst fractures of the lumbar and thoracic spine. PATIENTS AND METHODS: Within 22 months, we treated 30 patients (average age: 45, range: 20- 73 years, 16 females, 14 males) with unstable burst fractures of the thoracolumbar (n=20) and the thoracic (n=2) as well as lumbar (n=8) spine in two stages (primary dorsal transpedicular stabilization with fixateur interne under navigator guidance and intraoperative CT and secondary vertebral body replacement using the Synex). In three patients with osteoporosis we performed additional ventrolateral plate fixation. The complications of the operation were analyzed and the postoperative follow-up results were evaluated regarding stability, bony fusion, loss of correction, pain and neurological status.
RESULTS: There was one postoperative instability, two transient neurological deteriorations and one case with seroma of the pleura. At follow-up examination (mean follow-up 14 months) an average loss of correction of 1.6 degrees was measured. Without osteoporosis a loss of correction of 5 degrees was observed in one case. In four osteoporotic patients without ventrolateral stabilization a mean loss of correction of 10 degrees was present. At the follow-up examinations a bony fusion was documented in 27 and stability in all patients. Most of the patients stated either no or only minor pains at follow-up. Only two patients with pain of medium degree had to take pain medication.
CONCLUSIONS: The vertebral body replacement system Synex is a good technical possibility for a vertebral body replacement in unstable burst fractures of the thoracic and lumbar spine. With osteoporosis an additional anterior stabilization is to be recommended.