[99m Tc] Tc-MDP bone SPECT/CT diagnosing unstable slipped capital femoral epiphysis with secondary AVN in a patient with misleading knee pain.

Bone scan is highly sensitive whole-body imaging with relative low radiation in patients with non-localized skeletal symptoms. Patient is 12-year-old boy with Down syndrome, suffering recent claudication and exacerbated left knee pain unable to walk even with crutches. Three-dimensional Single photon emission computed tomography/Computed tomography (SPECT/CT) detected left slipped capital femoral epiphysis (SCFE) and secondary Avascular necrosis (AVN).