Achilles Tendon – Injuries and Ruptures
The Achilles tendon is the largest and strongest tendon in the human body. It is approximately 15cm in length and rotates clockwise up to 90 degrees, running from the soleus and gastrocnemius muscles and inserting into the back of the heel. The tendon is surrounded by a paratenon allowing it to glide back and forth. It is made up of Type I collagen giving it the ability store and release energy so that it can stretch and recoil like a spring in response to the stretch/shortening cycle of the gastrocnemius and soleus muscles – an important action for locomotion.
This unique structure allows the Achilles to withstand fast and dynamic loads, which can be up to 7 x a persons body weight during running and jumping activities. It also makes this tendon very susceptible to injury and makes rehabilitation very challenging.
The Achilles tendon is in fact the most commonly injured tendon in the human body. Most injuries occur in the mid-potion where there is limited blood supply or at the insertion in the heel.
Achilles Tendinopathy – This is a degeneration of the collagen fibres that form the tendon. It results in the tendon becoming painful and stiff and is generally seen following periods of excessive use – especially in de-conditioned and older tendons.
These injuries are managed differently depending on which part of tendon is injured and on the chronicity of the injury.
Treatment is based on a progressive tendon loading program to help promote tendon synthesis. These loading programs will be specific to each individual and the intensity and duration of the loads will be dependent on the classification of the tendinopathy.
Achilles Rupture - Complete Achilles ruptures are often traumatic and debilitating injuries and an orthopaedic assessment would be recommended. These have historically been surgically repaired due to the non-surgical alternative having high rates of re-rupture and risk of tendon lengthening.
However, over the last 20 years, the development of stricter rehabilitation protocols and the introduction of functional boots has lead to a reduction in the non-surgical re-rupture rates and an improvement in long term function. Most notably in 2011 Wallace reported that conservative management of 949 tendons had an overall re-rupture rate of only 2.8% when using a functional orthosis and following a rehabilitation protocol.
Non-surgical protocols have now been developed to offer a reasonable treatment option to surgical repair for an Achilles rupture. Although there is still higher re-rupture rates of non-surgically managed patients the rates of both interventions are low with only small differences between them (Huchinson et al).