In May 2015, an 8-year-old boy from Columbia, SC became the second child in the state to receive an extendible implant that replaced the leg bone that osteosarcoma had destroyed. Orthopaedic oncologist Lee Leddy, M.D., Associate Professor in the Department of Orthopaedics at MUSC Health, performed the surgery, removing the cancerous bone (and its growth plate) and replacing it with a device designed to be lengthened over time to ensure that both legs will be of equal length. During follow-up visits every four to six weeks, the boy will place his leg into a doughnut-shaped magnet that will drive a gearbox to extend the prosthesis nine centimeters, the remainder of the boy’s projected growth.
Prior to this technology, options for a child whose growth plate had to be removed due to cancer were amputation; rotationplasty, in which the child’s ankle is substituted for the knee joint; or implants that required repeated surgeries to lengthen the prosthesis. With this device, future operations are not necessary. More than 100 procedures have been completed in the U.S. with this device, but only two in South Carolina, both by Leddy at MUSC Health.
Leddy says this prosthesis is a dramatic improvement over the ways doctors previously met the challenges of limb salvage surgery in the skeletally immature patient. “Being able to reliably lengthen the extremity without surgery is a major advantage,” he says. “However, it is important to realize how critical the team approach is when treating these complex problems.”
The team of specialists who collaborated on these complex cases included musculoskeletal radiologists who interpreted radiographs and magnetic resonance imaging reports, pathologists who evaluated biopsy tissues, sarcoma-trained surgical oncologists who helped resect the cancer and reconstruct the extremity, operating room nurses, oncologists who made recommendations regarding chemotherapy, and physical therapists who worked with the patients to help return them to their active lives.
Leddy says that assuming a good response to chemotherapy and physical therapy, these patients can expect a full recovery.