MRI vs SPECT-CT in the diagnosis of fracture-related talar osteochondral lesions

The high prevalence of osteochondral talar lesions (OCTLs) in ankle fractures could explain the suboptimal functional outcomes in well-treated patients. The presence of OCTLs in magnetic resonance imaging (MRI) is not always related to symptoms, regardless of the existence of bone edema. On the other hand, single photon emission computed tomography (SPECT-CT) provides information on the metabolic activity and could have a better clinical-radiological correlation. The aim of the present study is to compare MRI versus SPECT-CT in terms of the clinical-radiological correlation of hidden OCTLs after ankle fractures considered arthrogenic.

An ambispective study was conducted in which 40 patients who underwent ankle fracture surgery were included. They completed the AOFAS and EFAS questionnaires and underwent MRI and SPECT-CT. Functional results were compared according to the presence or absence of OCTLs in each technique and based on the existence of bone edema in MRI and radiotracer uptake in SPECT-TC.

The detection of OCTLs by SPECT-CT was statistically related to worse results on the AOFAS scale (p < 0.05). Radiotracer uptake on SPECT-CT was related to worse results on the AOFAS scale (p < 0.05), while this difference was not found in OCTLs where bone edema was observed on MRI.

SPECT-CT appears to be superior to MRI in the detection of symptomatic fracture-related OCTLs. Furthermore, radiotracer uptake on SPECT-CT is associated with worse functional outcomes, being a more reliable marker than bone edema on MRI to evaluate the activity of OCTLs.