We have recently had two papers accepted in the Journal of Orthopaedic Research, following the successful New Frontiers in Tendon Research held in New York last September.

• Screen HRC, Birk DE, Kadler KE, Ramirez F, Young MF (2015) Functional Extracellular Matrix. Journal of Orthopaedic Research
• Spiesz EM, Thorpe CT, Riley GP, Birch HL, Clegg PD, Screen HRC (2015) Tendon extracellular matrix damage, degradation and inflammation in response to in-vitro overload exercise. Journal of Orthopaedic Research

Tendon ECM damage, degradation and inflammation in response to overload

The role of inflammation in tendon injury is uncertain and a topic of current interest. Inflammation is clearly present in some tendon injuries, but the long term, chronically painful tendon injuries often seen by doctors show no signs of inflammation. This is surprising, and has caused scientists trying to understand how tendon injuries develop some confusion. Without understanding how injury develops, it is hard to successfully develop treatments.

Recent data from our group and others suggests that long term chronic tendon injuries do show inflammation early on after injury, but that inflammation has often disappeared before the patient sees a doctor, which is why it has been missed. In this project we wanted to investigate this further and see how different types of loading may initiate tendon inflammation.

We took small section of tendon, and subjected them to loading simulating different amounts of use, such as low effort exercise like walking, and more demanding exercises like fast running for five or 30 minutes. Following those exercises we looked at the response of the tendon cells to the load, especially focusing on enzymes related to inflammation and tendon matrix breakdown.
We found out that a small amount of inflammation occurred early on after any exercise, but that with more exercise, the amount of inflammation increased. This is interesting, as it suggests that tendons do consistently respond to loading with inflammation, but that this might actually be beneficial and an important part of how they stay healthy, helping them respond to any damage from use. We now need to learn more about how to manage the inflammation and help the tendon heal effectively after injury.