SPECT‐CT Assessment of Pseudarthrosis after Spinal Fusion: Diagnostic Pitfall due to a Broken Screw

Abstract

A 43‐year‐old drug addicted female was referred for a L5‐S1 posterolateral in situ fixation with autologous graft because of an L5/S1 severe discopathy with listhesis. After six months, low back pain recurred. A Tc‐99m HDP SPECT‐CT diagnosed a pseudarthrosis with intense uptake of the L5‐S1 endplates and a fracture of the right S1 screw just outside the metal‐bone interface without any uptake or bone resorption around the screw. The absence of uptake around a broken screw is a pitfall that the physician should be aware of.