introduction

Introduction

Vetebroplasty is a percutaneous imaging-guided technique used for the treatment of pain and the strengthening of bone by injecting bone cements into a vertebral body.

The indications of this procedure are osteoporotic compression fractures and tumors (primary or secondary) of vertebral bodies.

Different kinds of cements are used and this study will describe the properties and the modalities of each cement and will illustrate the best indications for each of them.

Historical review

Bone cements were used for several decades in orthopaedic surgery in order to fix material and to strengthen bones.  Vertebroplasty was originally an exclusively open procedure performed to fill voids resulting from tumor resection or to fix pedicle screws.  However, this open procedure includes risks that should be avoided.

Therefore, Galibert and Deramond performed the first percutaneous procedure in 1984 in the treatment of a painful vertebral hemangioma of the C2 vertebra.  This technique was used in conunction with a first surgical laminectomy.

Encouraged by an excellent response, they continued their investigations and first published the results of seven patients treated by percutaneous vertebroplasty in 1987. They proposed the injection of polymethylmethacrylate (PMMA) in vertebral bodies with symptomatic hemangiomas in order to reinforce the bone and to relief the pain.

Following these first encouraging results, the indications of the vetrebroplasty were significantly expanded and now osteoporotic compression fractures, myeloma and metastatic osteolytic bone lesions account for the majority of them.

The first cement used with good clinical results was PMMA which is still used effectively.  However, the chemical and physical properties of this cement made it a less than optimal cement for some indications.

Therefore, other cements are now available such as composite cements (e.g., Cortoss®- ORTHOVITA®) and calcium phosphate cements (e.g., Norian SRS®, Calcibon®).  Their properties tend to make them more biocompatible and less toxic with bone tissues.

Review of injectable cements

PMMA is no longer the only injectable cements available for vertebroplasty.   In the past few years, new cements, some of which were already used in other indications, were modified  to an injectable form.  The goal of each manufacter is to find the best cement in terms of biocompatibility, injectability, mechanical properties, radiopacity, and rheological properties.

This chapter will describe the properties in each broad category of injectable cements:

• PMMA
• Composite cements
• Calcium phosphate cements