Peroneal Tendon Abnormalities on Routine Magnetic Resonance Imaging of the Foot and Ankle

Abnormalities of the peroneal tendons can frequently be identified on routine MRI of the foot and ankle. Previous studies in the orthopedic literature have discussed the prevalence of abnormal MRI findings in asymptomatic patients, most notably with regards to the spine and shoulder. The purpose of this study was to determine the prevalence of abnormal findings of the peroneal tendons on MRI in asymptomatic individuals.

We retrospectively reviewed all foot and ankle MRIs from 2 independent time periods that were either performed or reviewed at our institution. Studies were excluded if performed on patients with documented inversion injuries, ankle sprains, or lateral ankle trauma. A total of 294 (of 617) MRIs were eligible for inclusion in this study. A single attending musculoskeletal radiologist reviewed each MRI. Pathologies of the peroneal tendons included tendinosis, tenosynovitis, acute tears, chronic tears, and tendon splits. Additionally, the primary pathology encountered on each MRI was noted. The mean age of the MRIs included in this study was 46.8 years (range 9-82) with 155 females and 139 males.

The most commonly occurring primary pathology was Achilles tendinosis/tears (86), followed by posterior tibial tendon dysfunction (43). With regards to the peroneal tendons, 103 of the 294 (35%) MRIs demonstrated some pathology.

The results of this study demonstrated that a sizeable percentage of asymptomatic individuals could have peroneal tendon pathology on MRI of the foot and ankle. This study can have important clinical implications for when patients present with concerning MRI findings that do not correlate clinically. Physicians providing musculoskeletal care can counsel and reassure patients who present with peroneal pathology on MRI but an absence of clinical findings.

Level IV, case series.