Prevalence of Abnormal Ultrasonographic Findings in Asymptomatic Peroneal Tendons

BACKGROUND: The peroneus longus (PL) and peroneus brevis (PB) tendons comprise the lateral compartment of the leg and stabilize the foot during weightbearing. Peroneal tendinopathy can precipitate lateral ankle pain and induce functional disability. The progression of peroneal pathology to lateral ankle dysfunction is thought to stem from asymptomatic, subclinical peroneal tendinopathy. There may be clinical benefit to identifying asymptomatic patients with this condition before progression to disability. Various ultrasonographic characteristics have been observed in peroneal tendinopathy. The purpose of this study is to identify the frequency of subclinical tendinopathic characteristics in asymptomatic peroneal tendons. METHODS: One hundred seventy participants underwent bilateral foot and ankle ultrasonographic examination. Images were assessed for abnormalities of the PL and PB tendons by a group of physicians who recorded frequencies of abnormalities. This team consisted of an orthopaedic surgeon specializing in foot and ankle surgery, a fifth-year orthopaedic surgery resident, and a family medicine physician with musculoskeletal sonographer certification. RESULTS: A total of 340 PL and 340 PB tendons were assessed. Sixty-eight (20%) PL and 41 (12.1%) PB tendons had abnormal traits. Twenty-four PLs and 22 PBs had circumferential fluid, 16 PLs and 9 PBs had noncircumferential fluid, 27 PLs and 6 PBs had thickening, 36 PLs and 12 PBs had heterogenicity, 10 PLs and 2 PBs had hyperemia, and 1 PL had calcification. In Caucasian participants, male gender was associated with increased frequency of abnormal findings, but there were no other significant differences based on age, body mass index, or ethnicity. CONCLUSION: In our studied population of 170 patients who had no complaints of associated symptoms, we found that 20% of PLs and 12% of PBs displayed ultrasonographic abnormalities. When we included all unusual findings within and around the tendons, prevalence rates of ultrasonographic abnormalities were 34% for PLs and 22% for PBs. LEVEL OF EVIDENCE: Level II, prospective cohort study.