Primary bone tumors arise mostly around the knee. A treatment strategy issued from a multidisciplinary team is the key factor for an optimal management of such patients. Many durable options for reconstructing a functional limb are available, as an alternative to amputation, without lowering patients' survival. Nevertheless complications are frequent and any decision for one technique or the other should be made with the patient, appreciating the specificity of each single case. We discuss here the different techniques with their advantages and drawbacks, including long term results.