Use of the telescopic plate spacer in treatment of cervical and cervicothoracic spine tumors.
OBJECTIVE
We investigated the mechanical and in vivo properties of a novel device, called the telescopic plate spacer (TPS), designed to promote restoration of height, alignment, and stability after cervical corpectomy for tumor.


METHODS
The device first underwent mechanical testing. Comparisons were made with a commercially available anterior cervical plate. A caprine study was then performed. Twelve goats underwent a cervical corpectomy and placement of either a TPS filled with autograft or a plate and autograft. The animals were killed at 28 weeks and assessed for fusion. A prospective human study was then conducted. Fifteen patients with cervical or cervicothoracic tumors underwent corpectomy and placement of allograft-filled TPS. End points included pain scores and radiographic assessment of vertebral height, alignment, and stability.


RESULTS
In the mechanical study, the TPS outperformed the anterior cervical plate in all modalities except for torsion stiffness and tension-bending failure load. The caprine study demonstrated fusion in six of six cases at 28 weeks in the TPS group, compared with four of six cases in the plate and autograft group. In the human study, patients (n = 15) were stabilized with the TPS after corpectomy (range, 1-3 levels; average, 1.7 levels). There were no failures of instrumentation or neurological deterioration. Stability was achieved in all patients, with an average follow-up of 9 months. Durable improvements in pain scores (P = 0.001), vertebral height (P = 0.002), and reduction of kyphosis (P = 0.046) were achieved.


CONCLUSIONS
The TPS can be used to restore height, alignment, and stability after corpectomy.
Coumans
Jean-Valéry C E
JV
Department of Neurosurgery, The Cleveland Clinic Foundation, Ohio 44195, USA. coumans@prodigy.net
Marchek
Connie P
CP
Henderson
Fraser C
FC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates; D016025:Bone Transplantation; D002574:Cervical Vertebrae / Q000601:surgery*; D004867:Equipment Design; D006041:Goats; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D013125:Spinal Neoplasms / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery*