Vertebral body replacement with a bioglass-polyurethane composite in spinemetastases - clinical, radiological and biomechanical results

Metastatic spine lesions frequently require corpectomy in order to achieve decompression of the spinal cord and restoration of spinal stability. A var iety of systems have been developed for vertebral body replacement. In pati ents with prolonged life expectancy due to an improvement of both systemic and local therapy, treatment results can be impaired by a loosening at the implant-bone interface or mechanical failure. Furthermore, early detection of a metastatic recurrence using sensitive imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) is possible in these patients without artefact interference. The aim of our pilot study was to e valuate the clinical applicability and results of a new radiolucent system for vertebral body replacement in the lumbar spine. The system consists of bone-integrating biocompatible materials - a polyetherurethane/bioglass com posite (PU-C) replacement body and an integrated plate of carbon-fibre rein forced polyetheretherketone (CFPEEK)- and provides high primary stability w ith anterior instrumentation alone. In a current prospective study, five pa tients with metastatic lesions of the lumbar spine were treated by corpecto my and reconstruction using this new system. Good primary stability was ach ieved in all eases. Follow-up (median 15 months) using CT and MRI revealed progressive osseous integration of the PU-C spacer in four patients survivi ng more than 6 months. Results obtained from imaging methods were confirmed following autopsy by biomechanical investigation of an explanted device. F rom these data, it can be concluded that implantation of the new radiolucen t system provides sufficient long-term stability for the requirements of se lected tumour patients with improved prognosis.