CA Osteosarcoma for Below-Knee Amputation

Osteosarcoma or osteogenic sarcoma is a malignant neoplasm arising from primitive transformed cells of mesenchymal origin. This primary bone sarcoma has incidence of 4.6 per million people [1]. These cells have osteoblastic differentiation and produce malignant osteoid. It can be found in any age group but is prevalent in paediatric and adolescents. This tumour is more prevalent in fast-growing metaphyseal ends of long bones. This tumour frequently grows at proximal end of tibia, humerus or distal end of the femur. Osteosarcoma affects the knee in around 60% of cases whereas other areas are around the hip, shoulder and jaw with incidence of around 15%, 10% and 8%, respectively [2]. Osteosarcoma has male preponderance with male-to-female ratio of 2.3:1 [2]. The initial symptoms and signs may be night pain and tenderness around the knee, local mass, limited joint mobility and pathological fracture. X-ray imaging is an initial imaging of choice which shows sunburst appearance and Codman triangle while CT scan is useful to define anatomy and detect pathological fracture. Also, soft tissue and medullary cavity is better imaged with the help of MRI scan [3]. The tumour may metastasise to lungs and is seen as solitary or multiple nodular opacities on chest X-ray. The treatment of osteosarcoma is complete radical, en block surgical resection of tumour [4] and neoadjuvant or adjuvant chemotherapy. Surgery is usually done after neoadjuvant chemotherapy with an aim of limb salvage. Limb salvage surgery is possible in majority of patients [5] but may need amputation in case of complications, such as infection, non-union or loco-regional tumour recurrence. The patient present to the anaesthesiologists may present unique issues of post radiation and post chemotherapy status. The treatment requires close co-coordination between various specialists such as medical oncologists, orthopaedic surgeons, physical therapists, anaesthesiologists, critical care specialists and oncology nurses.