Treatment options for vertebral fractures an overview of different philosophies and techniques for vertebral augmentation

Abstract

For more than 30 years, minimally invasive surgical procedures have been available to stabilize the fractured vertebrae by cement augmentation leading to significant pain relief, a distinct improvement in quality of life and decreased mortality for patients suffering from osteoporotic vertebral compression fractures. This overview article is designed to provide information on the wide range of augmentation methods previously tested and clinically applied in surgery in an attempt to compile the clinically relevant information on safety and efficacy in the published literature. Based on an extensive literature review on the topic of "vertebral fractures--surgical augmentation techniques" we summarized the results of published clinical trials and experimental testing which address clinically relevant questions. The selection of the publications in reference books and scientific journals covers the time period from the end of the 1970s until the present. The final selection of more than 50 publications with, in the opinion of the authors, clinically relevant data led to the following results, which can be of significance for clinical application. The prerequisites for the success of all augmentation methods include the earliest possible surgical intervention, optimal technical equipment and an experienced, interdisciplinary team, as well as thorough consideration of the situation of the individual patient. The selection of the material for vertebral augmentation depends on the surgical method. The material of choice remains polymethylmethacrylate (PMMA), and the best record of efficacy and safety is displayed by radiofrequency kyphoplasty with ultrahigh-viscosity cement. Regarding clinical efficacy and safety, there are many convincing documentations showing superiority of vertebroplasty and kyphoplasty in comparison with conservative therapeutic regimens. Initial results of clinical studies with additional implants indicate a trend toward further improvement in clinical success and suggest possible broader clinical possibilities of application. Modern, minimally invasive augmentation techniques represent a real alternative to conservative treatment of patients with vertebral fractures. Further technical and clinical development in this area should aim at optimizing procedural safety while continuing to achieve comparably good results to current methods. Minimizing damage to the remaining trabecular structures as well as to adjacent vertebral disks and vertebrae should be paramount of importance. Options for the treatment of vertebral fractures: Reductions in bone density and pathological changes in bone structure are associated with an elevated risk of fractures, which can lead to decisive functional impairment, pain, and a host of further comorbidities. Vertebral augmentation can be considered as an alternative conservative treatment, in order to achieve immediate and lasting pain relief as well as improvement in functional impairment. To achieve greater safety, instrumentation for transpedicular access and incorporation of radiopacifiers in PMMA for vertebroplasty were developed in mid-eighties. Balloon kyphoplasty was introduced in the end nineties, and results of prospective, randomized clinical studies have confirmed the safety and efficacy; the destruction of the remaining native spongiosa structures during balloon expansion is viewed as a disadvantage of this method. The two step method of cavity creation followed by cement delivery known as kyphoplasty has been further refined and developed by and varied by technology/procedural developments. This includes most the radiofrequency kyphoplasty (DFINE Inc., San Jose, CA, USA), in which ultrahigh-viscosity cement is delivered at a controlled delivery rate, following producing a bone sparing size and side specific cavity which minimizes loss of spongiosa, allowing for mechanical stability upon interdigitation of cement into that remaining trabecular bone. This combination has been shown to preserve vertebral structures and reduces the risk of leakages. Finally, systems have been available in which cement augmentation of implants to enhance mechanical stability of the implants or the overall fracture is constructed by load sharing.