SPECT-CT and its role in foot and ankle pain differential diagnosis in the presence of metallic implants

Abstract

Objective: To show the role of SPECT CT in the study and differential diagnosis of foot an ankle pain in the presence of metallic implants. Methods: Twenty-two patients operated between 2008 and 2014 suffering from chronic foot and ankle pain, in the presence of metallic implants were retrospectively reviewed. The final diagnosis was confirmed combining imaging exams and disappearance of symptoms. We present the different diagnosis found and the percentage of patients in which the SPECT CT was useful. Results: Thirteen patients presented fractures previously treated with osteosynthesis (59.2%), 3 presented Osteochondral lesions treated with osteochondral grafts (13.6%), 2 foot fusions (9.1%), 2 ankle prosthesis (9.1%), 1 distal tibia osteotomy (4.5%) and one hallux valgus (4.5%). In 15 cases (68%) of the cases the SPECT CT confirmed the clinical origin of pain coincided with the metallic implant as suspected, and in 7 cases (32%) the SPEC CT showed a different origin of pain not related to the initial clinical diagnosis, modifying therefore the diagnosis and consequent treatment, resulting in resolution of pain. Conclusion: SPECT CT is a useful imaging tool in the differential diagnosis of foot and ankle pain in the presence of metallic implants, where clinical diagnosis and classical x ray imaging do not provide definitive information.