Ankylosing Spondylitis and Anerson Lesion Ankylosing Spondylitis is one of the Seronegative Spondyloarthropathy that if untreated results in Fused Stiff Spine. Even though the Spine is fused, It is brittle and prone to fracure even on minor trivial trauma. Anderson Lesion is a three column Injury seen in Ankylosing Spondylitis patients. It starts a minor microfracture that progressess to complete 3 column injury. Symptoms are usually Back pain that is present on change of posture and gets better with rest. if untreated the extent of fracture gradually increases and can result in Neurological Deficit. Treatment of Anderson lesion is primarily Surgical. Pedical screw stabilisation results in union usually in 4 to 6 months.