return to press release index 21 Septermber 2006 CUHK pioneers the use of minimally invasive and non-invasive lengthening prostheses in children bone cancer patients
Children¡¦s Cancer Foundation has been supporting the use of metallic prostheses in children since December 2002. The generosity of the Foundation has enabled orthopaedic surgeons to perform complex limb salvage surgeries in patients with technically challenging tumors. More than 13 patients have benefited from the Children¡¦s Cancer Foundation¡¦s sponsorship to-date. Without a custom designed prosthesis, these children would have faced the prospect of an amputation. The Foundation¡¦s prompt response to fund such expensive initiatives has major cost saving implications given that rehabilitation is faster and complications less likely to occur when prostheses are used. Children with bone cancer have good prospects for survival ¡V almost 75% of these children will remain alive, 10 years after their disease. Chemotherapy has not only improved survival but has enabled surgeon to perform limb salvage surgery in 80% of child patients. Surgical removal of the tumor is necessary for survival. Reconstruction of the removed bone is a must for the child to be able to walk. This is achieved either by using bone from a bone bank or specially manufactured metal prosthesis. However, as the child continues to grow, the affected limb remains shorter than normal, and poses a serious disadvantage in the lower extremity. A growing or extendible metallic prosthesis can rectify the problem of leg shortening. An extendible metallic prosthesis is specially designed to allow lengthening of the extremity, following its insertion. Although such growing prostheses have been used for more than 20 years, CUHK pioneered the mini-surgical approach for the lengthening of the device. The 1-cm only incision minimized the risk of infection and resulted in faster rehabilitation when compared to the open method used elsewhere in the world. The newest model of growing prosthesis is even more beneficial to patients. They do not need to go to the operating theatre and the prosthesis can be extended without additional surgery. There is a powerful magnet mounted inside the prosthesis. The patient simply needs to put his leg inside a specially-designed magnet driving machine to undergo the lengthening process and can be discharged immediately after the extension process. A short office procedure adds 4mm of painless incremental growth to the child¡¦s leg. Thus operating theatre time and resources can be saved, while patients do not face the risks and inconveniences of surgery. The innovative management of bone cancer in children has been possible because of a multidisciplinary team involving many academic departments of Faculty of Medicine CUHK. Since 2004, we have inserted minimally invasive growing prosthesis in 7 young patients with bone tumors and leg shortening. A non-invasive growing prosthesis was recently applied to a 16-year old boy and the lengthening process done in early September 2006, was painless and promising. Just like all mechanical devices, growing metallic prostheses will wear out, break or become loose with time. At present metal alloys used for the fabrication of these prostheses are much stronger, more durable and inert to the human body. Their survival is expected to be better than reported previously. Indeed 10-year survival of such mega prostheses has been reported to range from 80-90% in regions around the hip and 70-80% when used around the knee. The use of growing prosthesis has been a rewarding experience to surgeons and patients alike. It is being accepted as the state-of-the-art in the reconstruction of bone defects in young patients with primary bone tumors. |