Peroneal compartment pathology from a tertiary care county hospital: Imaging-based epidemiological study with clinical correlation

Abstract

Objectives

To assess peroneal compartment pathology frequency in patients with 3-T ankle MRIs for ankle pain/injury and correlate with clinical findings.

Method

373 patients with suspected internal ankle derangements who underwent 3-T ankle MRIs were included. The scans were independently reviewed by two blinded musculoskeletal radiologists, who classified cases as normal or exhibiting peroneal pathologies, including peroneus longus and brevis tenosynovitis, tendinopathy, tears, superior peroneal retinaculum injuries, and anatomical variants, based on established literature criteria. Agreement was assessed using Cohen's kappa, and pathologies were correlated with acute-versus-chronic pain and the presence/absence of laterality of pain.

Results

404 ankle MRIs from 373 patients (mean age, 49 years ± 12, 112 male) were evaluated. The overall frequency of peroneal tendon pathology was 71.0%, 34.4% common peroneal tenosynovitis, 12.6% peroneus brevis tenosynovitis, and 14.1% peroneus longus tenosynovitis. Peroneus brevis tendinopathy appeared in 22.5% of cases, with 23.5% partial/split tears and 0.5% complete tears. Peroneus longus tendinopathy appeared in 37.6% of cases, with 2.0% partial/split tears and 0.2% complete tears. Peroneus quartus was seen in 31.7% of cases, 4.0% had a low peroneus brevis muscle belly, and 40.1% had a thickened superior peroneal retinaculum.

Conclusion

Peroneal pathology is common on 3-T ankle MRIs. Chronic ankle pain correlates with tendinopathy, and lateral pain with tenosynovitis. Radiologists should note this high prevalence even without lateral pain, and assess retinaculum thickness to improve diagnostic confidence given correlation with tendon and tenosynovial abnormalities.