This study is for patients with resectable oligometastatic pulmonary osteosarcoma. The purpose of this phase three study is to determine if open surgical resection is superior to thoracoscopic resection for thoracic event-free survival (tEFS) in patients with resectable oligometastatic pulmonary osteosarcoma. The risks from this study are the usual risk of surgery such as bleeding, infection, injury to chest area, and pain after surgery. There is also the risk that additional surgery may be required to remove all cancer from the patient's lung. People in this clinical trial will receive surgery as the study therapy. The length of time surgery lasts can vary. After treatment, the patient will have follow-up examinations and medical tests.