Magnetic lengthening –newer technology to save limbs for bone cancer patients
For patients suffering from Osteosarcoma (a type of bone cancer), amputation and then living with severe disability was the only option left. But with the advancement in surgical skills and the advent of newer technology like the megaprosthesis using the magnetic lengthening technique, it is now possible to save not only the lives but also the limbs of these patients and help them lead a normal life.
Above all, among children the reconstruction is more challenging and the surgeons need to take care of the limb length discrepancy. At Bengaluru based BGS Global Hospitals 10 year old Srilankan boy has been the first to undergo the procedure in Karnataka a year ago. With history of pain and gradually progressive swelling in his left thigh and knee and identification of the problem, Binura was referred to BGS Global Hospitals by an orthopaedic surgeon from Colombo. At the hospital, Binura underwent a needle biopsy of the lesion and was diagnosed of Osteosarcoma of the distal femur (thigh) bone.
Following three cycles of chemotherapy which would shrink the tumor and prevent it from spreading to other parts of the body, surgery was planned for Binura to remove the affected tumor bone and reconstruct it with metallic prosthesis. Dr. Srinivas CH, Consultant, Orthopedic Onco-Surgeon at BGS Global Hospitals who had conducted the procedure said: “As the boy is still young and with an anticipated growth of 7 to 10 cms, the tumor bone removal would lead to arrested growth. Hence a special non invasive expandable prosthesis was designed and manufactured. This expandable prosthesis has an in built magnetic disc, gear box and a telescoping rod. When this prosthesis is placed in the magnetic field it would lead to rotation of the magnetic disc at 16,000 rpm and the telescoping rod would move leading to expansion of the prosthesis. The growth anticipated for Binura from that bone was calculated and the prosthesis designed accordingly. This prosthesis was then implanted.”
Meanwhile, Binura was again started on chemotherapy for another three cycles. He would walk into the out-patient department (OPD) every three months and place his leg in a magnetic coil and the limb would lengthen by 1 mm in 4 minutes. The required length will be achieved without any additional surgeries. Binura would have limb growth upto 14 to 15 years. After this period the expansion will be stopped.
Dr Srinivas further stated: “This technology is quite new and hence it is available at only few hospitals in India. It is also comparatively expensive. In India it is available at Mumbai and Bangalore. About 90% of the amputations following the bone cancer can be prevented with this technology, however awareness on the availability of such technology in India is still low.”