A Prospective Study of the IlluminOss Photodynamic Bone Stabilization System for the Treatment of Impending and Actual Pathological Fractures in the Pelvis From Metastatic Bone Disease or Geriatric Pelvic Fractures

The matrix morphology of the tumors in metastatic bone disease (MBD) may be of blastic, lytic, or mixed characteristics. Cancers of purely lytic or mixed blastic-lytic composition are the most concerning, as they result in local destruction of the cortical and trabecular bone, causing significant pain and increasing the risk of a pathologic fracture. Function and mobility are severely affected in this patient population due to mechanical and oncogenic pain. Prophylactic fixation of impending pathological fractures from MBD has demonstrated significant clinical benefit in terms of reducing mechanical pain and in decreasing the progression to complete pathologic fracture as well as minimizing the symptoms when these occur. In the later clinical scenario, the degree of fracture displacement, pain and functional limitation in most cases is minimal as the fracture is an already treated condition. In terms of surgical impact to the patient, prophylactic fixation is a faster procedure with lower blood loss rates. Other benefits include, shorter length of hospitalization and higher likelihood of discharge to home, in addition to reduction of pain, improvement in activities of daily living, and better quality of life. Importantly, efforts have been made to predict fracture risk and the need for prophylactic fixation based upon the clinical and radiographic features of MBD. This is well stablished in long bones of the extremities but it is not as clear or conclusive in the pelvis. Traditionally, Intramedullary devices are used for the purposes of prophylactic fixation and for treatment of pathologic fractures. Advantages include protection of the whole bone and ability to early bear weight given the biomechanical characteristics as a load sharing device. More commonly, these implants are made of titanium or other metal alloys. In recent years, the development of radiolucent implants has been important in orthopaedic oncology as these facilitate evaluation of bone involvement and radiation therapy planning. One of these radiolucent devices is IlluminOss PBSS. This UV light activated polymer has proved to be effective and safe in the treatment of impending pathologic fractures of the humerus. This intramedullary implant is inserted through small incisions and proved to be as effective as traditional intramedullary nails in relieving pain and returning patients faster to their pre-impending fracture level of activity. This product has been cleared by the FDA for use in the humerus, radius and ulna, clavicle, pelvis, fibula, metacarpals, metatarsals, and phalanges. The IlluminOss Photodynamic Bone Stabilization System can also be used in conjunction with FDA-cleared fracture fixation systems to provide supplemental fixation in these anatomic sites. The IlluminOss System may be used in the femur and tibia to provide supplemental fixation to an anatomically appropriate FDA-cleared fracture fixation system. Pelvic fractures in the elderly are a growing concern as the population ages. While oftentimes treated non-operatively, some require surgical fixation. In addition to the stress which surgery especially puts on geriatric patients, a return to pre-injury mobility is also an important impact and a concern of such procedures. Contrary to the extremities, there are minimal options for small incision pelvic implants to treat patients suffering from pain or fracture. The complex anatomy of the pelvis does not allow the use of rigid and precontoured implants. Fixation with screws is also challenging given the complex anatomy and high prevalence of vital neurovascular structures in the pelvis. The non-rigid nature of this polymer in the IlluminOss PBSS makes it suitable to adapt to the complex anatomy of the pelvis. In addition, there is no need to use screws for additional fixation, which is ideal in the pelvis. This implant may allow surgeons to forego the use of screws for fixation because the implant has a 3D anti-rotational profile which generates intrinsic stability when in contact with the inner bone. However, if the surgeon considers that stability is not sufficient, screws may still be used in this study at the surgeon's discretion. This device has been approved to be used in the pelvis after the experience in a previous study examining its effectiveness in the humerus, radius, and ulna. The purpose of this study is to collect information to effectively measure the improvement in pain control through functional scores after the surgery. We wish to see short term results (2 years) and to have a better understanding of the complication profile.