AJCC, American Joint Cancer Committee; ASCO, American Society of Clinical Oncology; Amputation; CATS, Computed Assisted Tumor Surgery; CCG, Children's Cancer Group; CI, Confidence Interval; COSS, Cooperative Osteosarcoma Study Group; CT, Computed Tomography; DFS, Disease Free Survival; FNA, Fine Needle Aspiration; LSS, Limb Salvage Surgery; Limb-salvage surgery; MAP, MTX, Adriamycin, Cisplatin; MRI, Magnetic Resonance Imaging; MSKCC, Memorial Sloan Kattering Cancer Center; MSTS, Musculoskeletal Tumor Society; NCCN, National Comprehensive Cancer Network; NOS, Newcastle­Ottawa scale; NPCR, National Program of Cancer Registries; Neoadjuvant chemotherapy; OR, Odds Ratio; OS, Overall Survival; Osteosarcoma; PET, Positron Emission Tomography; POG, Pediatric Oncology Group; RCT, Randomized Controlled Trials; Rev-Man, Review Manager; SEER, Surveillance, Epidemiology, and End Results; SIOP, International Society of Paediatric Oncology; Tc-MDP, Methylene diphosphonate with technetium-99m; VICC, Vanderbilt-Ingram Cancer Center