Data from: Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability

Background: Patellar tendinopathy (PT) is one of the most common knee
disorders among athletes. Changes in morphology and elasticity of the
painful tendon and how these relate to the self-perceived pain and
dysfunction remain unclear. Objectives: To compare the morphology and
elastic properties of patellar tendons between athlete with and without
unilateral PT and to examine its association with self-perceived pain and
dysfunction. Methods: In this cross-sectional study, 33 male athletes (20
healthy and 13 with unilateral PT) were enrolled. The morphology and
elastic properties of the patellar tendon were assessed by the grey and
elastography mode of supersonic shear imaging (SSI) technique while the
intensity of pressure pain, self-perceived pain and dysfunction were
quantified with a 10-lb force to the most painful site and the Victorian
Institute of Sport Assessment-patella (VISA-P) questionnaire,
respectively. Results: In athletes with unilateral PT, the painful tendons
had higher shear elastic modulus (SEM) and larger tendon than the
non-painful side (p<0.05) or the dominant side of the healthy
athletes (p<0.05). Significant correlations were found between
tendon SEM ratio (SEM of painful over non-painful tendon) and the
intensity of pressure pain (rho = 0.62; p = 0.024), VISA-P scores (rho =
−0.61; p = 0.026), and the sub-scores of the VISA-P scores on going down
stairs, lunge, single leg hopping and squatting (rho ranged from −0.63 to
−0.67; p<0.05). Conclusions: Athletes with unilateral PT had
stiffer and larger tendon on the painful side than the non-painful side
and the dominant side of healthy athletes. No significant differences on
the patellar tendon morphology and elastic properties were detected
between the dominant and non-dominant knees of the healthy control. The
ratio of the SEM of painful to non-painful sides was associated with pain
and dysfunction among athletes with unilateral PT.