Achilles and Patellar Tendon Morphology in Dancers with and without Tendon Pain

OBJECTIVES: To examine Achilles and patellar tendon morphology in dancers with and without tendon pain. METHODS: Fifty-three dancers with and without Achilles and/or patellar tendon pain participated. Eleven age-matched non-dancers served as controls. Longitudinal ultrasound images of the middle and distal Achilles and proximal and distal patellar tendons were acquired. To assess macromorphology, the thickness of the middle and distal Achilles and proximal and distal patellar tendons were measured. Micrornorphology was analyzed by selecting 2 x 2-mm(2) regions of interest in the tendons; spectral analysis using the fast Fourier transform was run for several kernels (2 x 2-mm(2) subimages) within each image, and the peak spatial frequency (PSF) was extracted. A one-way ANOVA compared asymptomatic, symptomatic, and control tendon thickness and PSF. RESULTS: Macromorphology: There was no significant difference between asymptomatic and symptomatic dancers in middle or distal Achilles tendon thickness and distal patellar tendon thickness. Proximal patellar tendons in control subjects were thinner than those in asymptomatic (p=0.036) and symptomatic (p=0.003) dancers. Micromorphology: There was no significant difference in PSF between asymptomatic and symptomatic dancers and controls in the Achilles or patellar tendon. CONCLUSION: Increased proximal patellar tendon thickness without changes in tendon rnicromorphology suggests that tendon adaptations are more likely activity-related and less likely influenced by degeneration.