Figure 1
From: Osteosarcoma of the spine: surgical treatment and outcomes
Surgical staging of spinal tumors, according to the WBB system. The transverse section is divided into 12 sectors (in a clockwise order) and into five concentric layers. (A) extraosseous soft tissue, (B) intraosseous (superficial), (C) intraosseous (deep), (D) extraosseous (extradural), and (E) extraosseous (intradural).