ABSTRACT
Objectives: To examine whether asymptomatic ultrasonographic abnormalities in the Achilles and patellar tendons in runners are associated with an increased risk of pain development.
Methods: This is a longitudinal, prospective cohort study with 139 runners recruited at a half and full marathon race. Ultrasound examination of the Achilles and patellar tendons was performed bilaterally the day prior to the race. Self-reported injury data were collected at 1, 3, 6 and 12 months. 104 (74.8%) runners were included in the data analysis.
Results: Ultrasonographic tendon abnormalities were found in 24.1% of the Achilles and in 23.1% of the patellar tendons prior to the race. Runners with tendon abnormality were 2–3 times more likely to develop pain within 12 months than those without (relative risk = 3.14, p = 0.010 for Achilles; relative risk = 2.52, p = 0.008 for patellar tendon). After adjusting for gender, age, years of running, average miles per week of running over a year, and pre-race pain, runners with ultrasound abnormality were about 3 times (hazard ratio = 2.89, p = 0.039 for Achilles; hazard ratio = 2.73, p = 0.030 for patellar tendon) more likely to develop pain after the race. Tendon delamination was most strongly associated with pain in both the Achilles (relative risk = 6.00; p = 0.001) and patellar tendons (relative risk = 3.81; p = 0.001).
Conclusions: Structural changes in asymptomatic tendons were found in almost 25% of runners. Presence of structural changes was associated with increased development of Achilles and patellar tendon pain within one year.
Acknowledgments
The authors would like to thank the coordinators of the Salt Lake City Marathon. Preliminary results of the study at 3-month follow-up were presented at the 2018 AMSSM annual conference in Orlando, Florida, but the study has not been previously published. Internal departmental research funding was obtained from the University of Utah Division of Physical Medicine & Rehabilitation. No additional funding was obtained for this study. The authors do not have any competing interests or other financial conflicts for this case.
Author disclosures
The authors declare no competing interests or financial benefit in this original research.
Declaration of interest
No potential conflict of interest was reported by the authors.