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Updated: Oct 5, 2025
Evaluation of Stem Cell Therapies in a Bilateral Patellar Tendon Injury Model in Rats
Published on: March 30, 2018
Decreasing patellar tendon stiffness during exercise therapy for patellar tendinopathy is associated with better
Stephan J Breda1, Robert-Jan de Vos2, Gabriel P Krestin3
1Department of Radiology & Nuclear Medicine, Erasmus MC University Medical Center, the Netherlands; Department of Orthopedics & Sports Medicine, Erasmus MC University Medical Center, the Netherlands.
Objectives:
To assess the associations between: 1) baseline patellar tendon stiffness and clinical outcome after exercise therapy in athletes with patellar tendinopathy and 2) the change in patellar tendon stiffness and clinical outcome during progressive tendon-loading exercise therapy and eccentric exercise therapy.
Design:
Randomized controlled trial.
Methods:
Athletes with patellar tendinopathy aged 18-35 years, playing tendon-loading sports at least 3 times per week were randomized in a 1:1 ratio between progressive tendon-loading exercise therapy and eccentric exercise therapy for 24 weeks. Patellar tendinopathy was diagnosed clinically, and confirmed by ultrasound. Patellar tendon stiffness (kilopascal, kPa) was assessed using shear-wave elastography. Clinical outcome was assessed using the validated Victorian Institute of Sports Assessment (VISA-P; range 0-100) questionnaire. Both were assessed at baseline, 12 and 24 week follow-up. Adjusted general linear, mixed-linear models and Generalized Estimating Equations were used.
Results:
We included 76 athletes (58 men, mean age 24 ± 4 years). No association was found between baseline stiffness and VISA-P after 24 weeks (p = 0.52). Decreased stiffness (adjusted mean difference = 10 kPa (95% CI: 4-15) was significantly associated with improved clinical outcome at 12 weeks in all athletes (p = 0.02), and at both 12 and 24 weeks (p = 0.01) in athletes allocated to progressive tendon-loading exercise therapy.
Conclusions:
Patellar tendon stiffness, assessed with shear-wave elastography, is unsuitable to use as a single predictive measurement for clinical outcome. Decreasing stiffness during the course of exercise therapy is associated with improved clinical outcome in athletes recovering from patellar tendinopathy.
