In 2004, an active 14-year-old teen arrived in the office of Richard J. O'Donnell, M.D., chief of orthopaedic oncology at UCSF Medical Center. The young man had a lesion in his proximal femur that tests revealed to be a Ewing's sarcoma. Removal would require a massive hip replacement.
O'Donnell and his team were confident there were multiple treatment options that would preserve the young man's life, and worked with him and his family to sort through those options. The family wanted to salvage the limb, but there was concern that the bone loss from stress shielding and wear that commonly causes cemented and press-fit devices to fail would dictate multiple surgeries throughout the young man's life.
O'Donnell had an alternative. A pioneer in compressive osseointegration — a technique in which a spring-loaded implant applies hundreds of pounds of pressure to hold an "anchor plug" in the remaining bone — O'Donnell believed the technique promised a better quality of life than traditional limb salvage surgery, without increasing the risk of complication.
"In the hands of an experienced surgeon, the success rate with this procedure is exceedingly high," says O'Donnell, who has done more of these procedures than any other practicing surgeon in the world — more than 150 — and who, together with UCSF professor emeritus James O. Johnston, M.D., oversaw the multicenter clinical trial that led in 2003 to FDA clearance of the device used in the procedure. "In addition, the compression force actually encourages bone to grow around and into the titanium implant, thereby providing long-term stability."
Four years later, the cancer-free young man sends O'Donnell pictures of the hikes he takes in areas around California.
Of course, long-term prognoses always depend on the full spectrum of cancer care — and a closely coordinated team. Pediatric medical oncologist Steven G. DuBois, M.D., notes, "You can't cure bone sarcoma patients with surgery or chemo alone; it requires both."
"Treatment choices need to be made at a place that understands what's possible," says pediatric medical oncologist Robert E. Goldsby, M.D. At UCSF Medical Center, these options and the latest research are discussed at two tumor boards run by the pediatric multidisciplinary program and the sarcoma program.
While each case is different, treatment usually begins with 12 weeks of chemotherapy, at which time the team gathers to evaluate the response. "After repeat staging studies, the next step is local control," says DuBois. "Even if the patient's tumor is progressing, we almost always need to resect the tumor." After surgery, patients typically undergo another six to eight cycles of chemotherapy.
The sarcoma program also conducts long-term follow-up in collaboration with patients' community providers. Goldsby, who directs the Survivors of Childhood Cancer Program at UCSF Benioff Children's Hospital, says that all patients receive a wallet-sized card to remind them of recommended follow-up care. The pediatric team sends a more detailed version of those recommendations to patients' community physicians.
Compressive osseointegration patients typically return to UCSF for regular imaging studies every three to six months. Some patients from the East Bay, South Bay, Central Valley and Sacramento areas come to a recently opened satellite office at ValleyCare Medical Center in Pleasanton.
"We believe that for patients with lower extremity tumors, compressive osseointegration is an excellent alternative that results in successful, long-term limb preservation more than 90 percent of the time," says O'Donnell.
To contact Dr. Richard O'Donnell, call (415) 885-3800.
When Amputation is the Treatment Choice
Sometimes, for reasons both clinical and personal, osteosarcoma patients opt for amputation. For these patients and for post-traumatic patients, immediate postsurgical prosthesis fitting can offer many clinical benefits.
"After an amputation and once the wound is closed in the operating room, the prosthetists place the residual limb in a soft tissue container [cast] to compress the tissue, and attach a plate to the cast," says Walter Racette, director of the Orthotic and Prosthetic Service at UCSF Medical Center.
"The next day, we can attach the remainder of the prosthesis for early weight bearing." This procedure is repeated once the cast gets loose, and is continued until wound healing is complete, at which time a preparatory prosthesis is provided.
The even pressure of the cast helps to reduce edema and provide a favorable healing environment. "It also prevents contracture, protects the wound and allows the patient to get up right away," says Racette.
Stem Cells and Tissue Regeneration
With a major stem cell research grant, Ophir Klein, M.D., Ph.D, is exploring the molecular processes that regulate the behavior of dental stem cells in mice, with the goal of promoting tooth regeneration and treating craniofacial abnormalities in humans.