Talocalcaneal Coalition With Os Sustentaculum

Os sustentaculi is a rare accessory bone of the foot located along the posterior end of sustentaculum tali. It is a component type of extra-articular talocalcaneal coalition. We report the case of a 17-year-old boy with symptomatic os sustentaculum with talocalcaneal coalition diagnosed on 99mTc-HDP SPECT/CT. We wish to emphasize on the use of SPECT/CT in not only characterizing the ossicle morphologically, but also for evaluation of this anatomical variant as an active source of pain in the absence of a more common cause of pain in young physically active patients.