Combination of Percutaneous Screw Fixation and Cementoplasty for Lytic Bone Metastases

In oncology, therapeutic progress has allowed a significant increase in life-expectancy: a growing number of cancer survivors live to more advanced metastatic stages. Consequently, the prevalence of secondary bone lesions is increasing, which are frequent and disabling. They are responsible for pain and a high risk of pathological fractures. The average prevalence of pain in cancer represents 53% for all stages combined and 64% for metastatic stages.

Analgesics, radiotherapy and surgery are widely used in this context, but are not without side effects.

Cementoplasty is an interventional radiology procedure that has improved the palliative management of bone lesions. It consists of a percutaneous injection of polymethylmethacrylate-based cement, whose physical and chemical properties provide resistance to compressive stress during weight-bearing activities. However, one of the main disadvantages of cement is its low resistance to torsional stress, as evidenced notably in vitro tests. Thus, cementoplasty alone is very effective at the spinal level (compressive forces) to reduce pain and risk of fracture, but much less effective at the level of other bones that are subjected to torsional stresses, notably the pelvis and femur (40% fracture rate at one year after cementoplasty alone of femoral metastasis).

Fixation using a combination of metal screws and cement provides resistance to torsional and compressive stress. In addition, it has been shown that there is a significant risk of secondary screw displacement if screws are not combined with cement in secondary bone lesions. Combination of percutaneous screw fixation and cementoplasty is a mini-invasive procedure which allows limiting complications and the duration of treatment: early standing up, almost no blood loss, reduced risk of venous thromboembolism (VTE), rapid healing.