Fig. 2.

Kaplan–Meier estimated survival in patients with primary osseous spinal tumors that were: a confined (tumor confined to cortex of bone or extension beyond cortex but confined within periosteum) or b locally invasive (extension beyond periosteum to surrounding tissues, including adjacent skeletal muscle, adjacent bone/cartilage, or skin). Surgery was associated with increased survival for both primary spinal tumors that were confined (p < 0.01) or locally invasive (p < 0.001)