Midportion Achilles tendinopathy (MPT) is a common problem in running athletes. Nevertheless, its etiology is not fully understood, and no valid prognostic criterion to predict the development of MPT could be identified to date. The purpose of the present study, therefore, was to evaluate whether power Doppler ultrasonography (PDU) is a suitable method to identify a predisposition to MPT in yet asymptomatic runners.
At 23 major running events, 634 asymptomatic long-distance runners were tested for Achilles tendon thickness, vascularization, and structural abnormalities using a high-resolution PDU device (Toshiba Aplio SSA-770A/80, 12 MHz). In addition, their medical history and anthropometric data were documented. All subjects were contacted 6 and 12 months later and asked about any new symptoms. The collected anamnestic, anthropometric, and ultrasonographic data were subjected to regression analysis to determine their predictive value concerning the manifestation of midportion Achilles tendon complaints (P < 0.05).
The highest odds ratio (OR) for manifestation of MPT within 1 yr was found for intratendinous blood flow (“neovascularization,” OR = 6.9, P < 0.001). An increased risk was also identified for subjects with a positive history of Achilles tendon complaints (OR = 3.8, P < 0.001). A third relevant parameter, just above the level of significance, was a spindle-shaped thickening of the tendon on PDU (Wald χ2 = 3.42).
PDU detection of intratendinous microvessels in the Achilles tendons of healthy runners seems to be a prognostically relevant factor concerning the manifestation of symptomatic MPT. This finding lays the foundation for an early identification of a predisposition to MPT as well as prophylactic intervention in as yet asymptomatic runners.
1Department of Orthopaedics and Traumatology, Albert-Ludwigs University Freiburg, Freiburg, GERMANY; 2Applied Research and Development Physiotherapy, Health Section, Bern University of Applied Sciences, Bern, SWITZERLAND; 3University Outpatient Clinic, Center of Sports Medicine, Sports Medicine and Sports Orthopaedics, University of Potsdam, Potsdam, GERMANY; and 4Department of Rehabilitative and Preventive Sports Medicine, Albert-Ludwigs University Freiburg, Freiburg, GERMANY
Address for correspondence: Heiner Baur, Ph.D., Bern University of Applied Sciences, Health Section, Applied Research and Development Physiotherapy, Murtenstrasse 10, CH-3008 Bern, Switzerland; E-mail: firstname.lastname@example.org.
Submitted for publication December 2010.
Accepted for publication June 2011.