Distractable vertebral cages for reconstruction after cervical corpectomy.

Abstract

Retrospective study of 20 patients with degenerative cervical spinal canal stenosis who were treated with corpectomy followed by the placement of a distractable titanium cage (anterior distraction device [ADD]) (Ulrich GmbH & Co. KG, Ulm, Germany). To investigate the efficacy of distractable titanium cages for reconstruction following decompressive cervical corpectomy. Anterior corpectomy and reconstruction for extensive spinal canal stenosis are standard techniques. The reconstruction is commonly performed with bone graft and anterior plating. Alternatively, different fusion cages have gained acceptance in spine surgery. However, in traditionally designed cages, an over-distraction of the involved segment is necessary to place the cage into the defect, and to achieve tight contact between cage and endplates. The new designed cage (ADD) can be distracted in situ. Therefore, the height of the cage can be adjusted precisely to the size of the corpectomy. All patients were treated with corpectomy followed by the placement of an ADD. A cervical plate was added in 13 cases, and an "All-in-one-system" (i.e., a cage with an attached plate with 2 holes for screw fixation on both sides, ADD) was used in 7. Follow-up was 18-60 months. Clinical evaluation and radiographs were performed after 3, 6, and 12 months, and then once a year. In all cases, a stable reconstruction of the anterior column was achieved, with no signs of instability on flexion/extension radiographs. However, there was one incidence of cage subsidence. According to Odom criteria, 11 patients (55%) had excellent outcome, 4 (20%) good, 3 (15%) satisfactory, and 2 (10%) poor. The results of the study show that distractable cages are useful vertebral body replacements because they can be adjust to the size of the corpectomy in situ and provide immediate strong anterior column support, avoiding bone graft site morbidity. The possibility of direct cage fixation without an additional plate simplifies the procedure.