This phase III trial compares the effect of open thoracic surgery (thoracotomy) to thoracoscopic surgery (video-assisted thoracoscopic surgery or VATS) in treating patients with osteosarcoma that has spread to the lung (pulmonary metastases). Open thoracic surgery is a type of surgery done through a single larger incision (like a large cut) that goes between the ribs, opens up the chest, and removes the cancer. Thoracoscopy is a type of chest surgery where the doctor makes several small incisions and uses a small camera to help with removing the cancer. This trial is being done evaluate the two different surgery methods for patients with osteosarcoma that has spread to the lung to find out which is better.