Magnetic Resonance Imaging Analysis of Peroneal Tendon Pathology Associated With Low-Lying Peroneus Brevis Muscle Belly: A Case-Control Study.

BACKGROUND

Low-lying peroneus brevis tendon muscle belly has been speculated to be an associated factor with symptomatic peroneal tendon pathology. Multiple studies have analyzed normal and anomalous anatomy associated with peroneal tendon pathology; however, no study has confirmed the clinical association between peroneal tendon pathology and low-lying peroneus brevis muscle belly.

PURPOSE: To identify the correlation of low-lying peroneus brevis muscle belly with peroneal tendon pathology.

STUDY

DESIGN

Case-control study; Level of evidence 3.

METHODS

The level of peroneus brevis muscle belly was compared between patients with symptomatic peroneal tendon pathology (experimental group) and asymptomatic individuals with otherwise normal lateral ankle using magnetic resonance images.

RESULTS

Of the 32 consecutive patients with symptomatic peroneal tendon pathology, 28 (87.5%) demonstrated peroneus brevis muscle distal to the fibular groove while 53.8% of control patients demonstrated such findings (P = .022). The most common diagnosis associated with peroneal tendon pathology was ankle instability and osteochondral defect of the talus or tibial plafond. Peroneal tendon pathology in isolation was less common.

CONCLUSION

Peroneal tendon pathology is often associated with lateral ankle instability and osteochondral defects of the ankle joint. Low-lying peroneus brevis muscle belly may be a common anatomic variant, but in the setting of instability it can become a source of pain and pathology secondary to overcrowding.

LEVELS OF EVIDENCE: Diagnostic, level III: Case-control study.