Management of Juxtaphyseal Malignant Bone Tumors Around the Knee Joint: New Concepts in Limb-Sparing Surgery

Prior to the 1970s, amputation or disarticulation was the standard treatment for malignant bone tumors in pediatric patients. Limb-sparing surgeries are now standard treatment due to multidisciplinary advancements in areas including radiological evaluation, chemotherapy, surgical techniques, implant technology, and tumor biology. Reconstruction methods of limb salvage include allograft, endoprostheses, and recycled autografts such as autoclaved bone and irradiated bone. However, limb function remains limited and deteriorates over time. When subsequent complications such as deep infection, fracture, and implant failure occur, it is likely that amputation or disarticulation may need to be eventually performed to solve problems. Therefore, biological reconstruction using distraction osteogenesis or frozen autograft was developed to obtain better limb function and reduce complications for bone tumor reconstruction. Our goal of limb-sparing surgery is the normalization of the affected limb in function and appearance. Based on this concept, we first performed and have been continuing biological reconstruction using a distraction osteogenesis technique and massive frozen tumor-bearing bone treated with liquid nitrogen. In this chapter, we introduce our two original biological reconstruction procedures for malignant tumors according to our classification (Types I–VI) based on tumor site, size, and response to chemotherapy. Cases indicated for joint preservation with the distraction osteogenesis method should have tumors of Types I–IV according to our classification system, of not more than 15 cm in length (resulting in a treatment time of less than one year), and with a good response to chemotherapy. Types V and VI are indicated for arthrodesis with distraction osteogenesis. The frozen autograft method can be applied to all types.