Sonography of the Achilles tendon in hypercholesterolaemia

Objectives. Tendon xanthomas cause thickening of the tendon and are an important sign in monogenic familial hypercholesterolaemia (FH). The aim of our study was to investigate the usefulness of achilles tendon sonography in detecting FH patients. Special attention was paid to structural abnormalities of the achilles tendon. Design. A clinical study with methodological testing. Setting. Patients suspected of having FH were sent to the out-patient Department of Medicine from other departments of Turku University Central Hospital and from primary care units. The patients were studied by high-frequency ultrasound before more exact typing of the lipid disorder. An additional study of normolipidaemic volunteers and a phantom study were also carried out. Subjects. Forty FH patients, 51 non-FH hypercholesterolaemia patients and 41 normolipidaemic volunteers were included in the study. Main outcome of measures. The thickness of the tendon was measured and the tendon structure and its echogenicity were recorded. Results. Twenty-five out of 40 (63%) FH patients had distinctly thickened tendons (men more than 10 mm, women more than 9 mm). Thirty-six (90%) had a typical structural alteration of low or mixed echogenicity of the tendon. Three non-FH patients were found to have xanthomas on sonography. Conclusions. We conclude that ultrasonography is a sensitive method of detecting xanothomas that reveals the altered tendon structure even in xanthomatous tendons of normal thickness.