Class I: No significant neurologic involvement
Class II: Involvement of bone without collapse or instability
Class III: Major neurologic impairment (sensory or motor) without significant involvement of bone
Class IV: Vertebral collapse with pain due to mechanical causes or instability but without significant neurologic compromise
Class V: Vertebral collapse with pain due to mechanical causes or instability combined with major neurologic impairment
Provide an explanation for key principles and pertinent aspects of the classification
Insert figures illustrating the classification
van der Linden YM, Dijkstra SPDS, Vonk EJA, Marijnen CAM, Leer JWH, Dutch Bone Metastasis Study Group. Prediction of survival in patients with metastases in the spinal column: results based on a randomized trial of radiotherapy. Cancer. 2005 Jan. 15;103(2):320-328.