Clinical research is directed towards a variety of issues important for adult and pediatric orthopaedic oncology. Major areas of interest include means of prosthetic fixation for massive skeletal reconstructions, multimodal neoadjuvant management of soft tissue sarcomas, and use of bone graft substitutes for treating cystic bone defects.
List of Projects & Funding
Biomet ComPreSs(TM) System
Work is focusing upon development of a novel means of fixation for prostheses devices used to reconstruct skeletal defects in cases of tumor resection and failed arthroplasty. By utilizing a high compression pre-stress concept, this implant seeks to avoid the use of long intramedullary stems and cement that have been associated with stress shielding, osteolysis, and ultimate failure. In contrast, the ComPreSs(TM) system provides immediate, rigid fixation that results in bone hypertrophy in response to compression forces. This enhances the success and longevity of limb salvage procedures, especially in young, active individuals. The work is supported by a grant from the Biomet Corporation in Warsaw, Indiana.
Multimodal Neoadjuvant Treatment of Soft Tissue Sacomas
Arising at a rate of just twenty new cases per year per million people, soft tissue sarcomas remain one the rarest forms of cancer. Fortunately, advances in radiologic imaging, surgery, radiation therapy, and chemotherapy have served to improve local control and overall survival. Work is underway to implement a Northern California regional protocol for the multimodality treatment of children and adults with soft tissue sarcoma. Wide surgical resection and external beam radiation therapy remain the mainstays of treatment. However, high dose rate brachytherapy and intraoperative radiation methods are being used increasingly to apply radiation where it is needed most--- directly to the tumor bed at the time of surgery. For patients younger than 65 with large, deep, high grade tumors, pre-operative or neoadjuvant chemotherapy is also being offered in an attempt not only to treat the tumor itself, but also to decrease the risk of metastatic disease, thereby increasing overall survival.
Bone Graft Substitutes for Bone Defects
A variety of options are now available for the treatment of bone defects that arise from both benign and malignant processes. Dr. James Johnston has helped to pioneer the use of bone cement for giant cell tumor, as well as the addition of threaded pin "rebar" to reinforce cement in cases of metastatic bone deficiency. For more benign cystic conditions of bone, newer substitutes such as coralline hydroxyapatite, are being utilized. These materials provide a matrix for bone healing while avoiding the potential complications of taking bone graft from the patient or from a bone bank.
