Vertebral Body Replacement With an Expandable Cage for Reconstruction After Spinal Tumor Resection

Issada Thongtrangan, M.D.; Raju S. V. Balabhadra, M.D.; Hoang Le, M.D.; Jon Park, M.D., F.R.C.S.C.; Daniel H. Kim, M.D.

Disclosures

Neurosurg Focus. 2003;15(5) 

In This Article

Abstract and Introduction

Object: The authors report their clinical experience with expandable cages used to stabilize the spine after vertebrectomy. The objectives of surgical treatment for spine tumors include a decrease in pain, decompression of the neural elements, mechanical stabilization of the spine, and wide resection to gain local control of certain primary tumors. Most of the lesions occur in the anterior column or vertebral body (VB). Anterior column defects following resection of VBs require surgical restoration of anterior column support. Recently, various expandable cages have been developed and used clinically for VB replacement (VBR).
Methods: Between January 2001 and June 2003, the authors treated 15 patients who presented with primary spinal tumors and metastatic lesions from remote sites. All patients underwent vertebrectomy, VBR with an expandable cage, and anterior instrumentation with or without posterior instrumentation, depending on the stability of the involved segment. The correction of kyphotic angle was achieved at an average of 20°. Pain scores according to the visual analog scale decreased from 8.4 to 5.2 at the last follow-up review. Patients whose Frankel neurological grade was below D attained at least a one-grade improvement after surgery. All patients achieved immediate stability postsurgery and there were no significant complications related to the expandable cage.
Conclusions: The advantage of the expandable cage is that it is easy to use because it permits optimal fit and correction of the deformity by in vivo expansion of the device. These results are promising, but long-term follow up is required.

The spinal column is the most common site of bone metastasis.[4] In patients who are asymptomatic, the thoracic spine is involved in 70% of cases, whereas the cervical and lumbar regions are affected in 10 and 20%, respectively.[8] Metastatic carcinoma from the lungs, prostate, breasts, kidneys, thyroid, and gastrointestinal tract account for the majority of spinal column tumors. Other lesions that commonly metastasize to the spine include myeloma and lymphoma. Certain primary tumors (chordoma, osteoblastoma) tend to occur most frequently in the spinal column; however, they represent less than 2% of all spine tumors.[4]

The objectives of surgical treatment for spine tumors include a decrease in pain, decompression of the neural elements, mechanical stabilization of the spine, and wide resection to gain local control of certain primary tumors. Most of the lesions occur in the body of the vertebra. Anterior column defects caused by resection of VBs require surgical restoration of anterior column support. In recent years, several artificial materials and implants have been developed to replace the VB, and bone cement is still widely accepted for this purpose.[10] Titanium cages;[1] ceramic,[11,14] ceramic/glass,[13] and carbon fiber spacers;[3] and different special implants[17] are also used clinically.

Recently, various expandable cages have been developed and used clinically for VBR, although there is a paucity of literature regarding the outcomes and results of using synthetic vertebral spacers and expandable cages. The advantage of the VBR expandable cage is that it is easy to place because it permits an optimal, tight fit and correction of the deformity by in vivo expansion of the device. Our primary goal in this paper is to report our clinical experience in the use of expandable VBR cages in patients with tumors.

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