Cementoplasty and musculoskeletal interventions

Introduction Nearly 60% of oncologic patients will eventually develop osseous metastasis with bone pain, potential fracture, and impaired mobility. While the first-line therapy for these patients is often medical, including narcotic analgesics, according to the World Health Organization recommendations, and bisphosphonate therapy such as zoledronic acid infusions, a significant portion of patients have intractable pain. Similarly, those patients who are treated with palliative external-beam radiotherapy may have incomplete pain relief that is not always durable. Furthermore, pain relief from radiotherapy can take up to 4 weeks and can be complicated by osteonecrosis or neural damage. The high percentage of oncologic patients suffering from painful metastatic bone lesions and their fractures, compounded with suboptimal results of conservative medical and radiotherapy, have been the drivers for development of minimally invasive local treatments, including embolization, ablation, and cement augmentation (also known as cementoplasty or osteoplasty). Percutaneous cementoplasty is a term referring to the injection of poly methylmethacrylate (PMMA), a polymer (similar in certain ways to orthopedic cement) inside an osseous structure through a trocar under imaging guidance. When the technique is applied in the spine, the term used is vertebroplasty. Alternatives to standard vertebroplasty include balloon kyphoplasty, augmented vertebroplasty by means of stents, nitinol cages, and polyether ether ketone (PEEK) polymer cages, and radiofrequency-mediated vertebroplasty or kyphoplasty. When one of these techniques is applied to the sacrum the term used is sacroplasty. Cement injection in peripheral bones is described by the term osteoplasty. The first ever description of imaging-guided cement injection was performed by Galibert et al. for the treatment of an aggressive cervical hemangioma. A wider term now used to include all these percutaneous approaches of material injection inside bone is bone augmentation. Indications When considering oncologic patients a strict definition of the treatment goal is necessary for best practice and outcomes. Palliative goals include cement injection for pain reduction in patients with multiple metastases, some of which are painful. Currently, new technologies and material allow us to consider curative treatment, which can be performed in oligometastatic patients, aiming at both local control and necrosis of the tumor as well as pain reduction and mobility improvement. In the latter case, cementoplasty must be combined with other therapies. such as radiotherapy, ablation, embolization, or surgical resection and/or fixation.