What is Achilles Tendonitis?
Often, and inaccurately, any pain around the Achilles is referred to as Achilles tendonitis. Achilles tendonitis refers to one specific and defined pathology of several which exist, and can co-exist. It is useful the divide the different problems of the Achilles tendon into those which affect the main “body” of the Achilles tendon (these conditions are tendonitis, tendonosis and rupture) and those conditions with affect the insertion of the Achilles tendon into the bone (insertional tendonosis of the Achilles tendon, a Hagglunds deformity).
What does Achilles Tendonitis look like?
The Achilles tendon itself structurally can be thought of almost like a horses tail with lots of longitudinal fibres running parallel to each other and packed very tightly. This is the substance of the Achilles tendon(2). Over a period of time, sometimes following multiple smaller injuries, areas of the body of the Achilles tendon can start to lose their normal well defined structure. In these areas the Achilles tendon itself becomes less well defined and the normal longitudinal fibres are less visible. This type of degenerative change within the Achilles tendon is known as tendonosis(1) and this usually results in a symmetrical swelling and area of localised pain in the tendon.
The healthy, and unhealthy, Achilles tendon is surround circumferentially by a fine covering known as the paratenon(3). This layer looks something like a sausage skin and has various functions including lubrication and supplying blood to the tendon. When this layer becomes inflamed then the condition is known as Achilles tendonitis. It should be realised that both Achilles tendonitis as well as Achilles tendonosis may co-exist in the same Achilles tendon.
Insertional Problems of the Achilles
Pain from the insertion of the Achilles tendon can be due to a healthy Achilles tendon being compressed against the heel counter of the shoe by a prominence at the back of the heel (known as a Hagglunds deformity).
Bilateral Hagglunds deformities
at the point of Achilles tendon insertion into the heel.
Alternatively, or in addition, the inserting Achilles tendon itself may have undergone degenerative change in this localised part of the tendon. This will result in Achilles tendonosis being associated with a Hagglunds deformity.This produces a more diffuse thickening across the back of the heel.
Symptoms of Achilles Tendonitis?
The main problem with Achilles tendonitis, or Achilles tendonosis, is one of pain. This generally remains well localised to the problematic area of the tendon. Initially symptoms are intermittent and may just occur following periods of activity. If the problem is an insertional Achilles tendonosis or a Hagglunds deformity, then symptoms may predominantly occur in particular shoe wear.
Though the symptoms with all of these Achilles problems are not discriminatory between the different types of problems which can occur. The pain with Achilles tendonitis may initially occur just during or after activity. It may produce symptoms at rest or occasionally even at night. It is also possible that some patients with degenerative tendon problems (Achilles tendonosis) may have little in the way of symptoms initially.
Causes of Achilles Tendonitis ?
Achilles tendons, like all musculo-skeletal tissue, are exposed to multiple episodes of minor trauma during their activity. All tendons are constructed very much for strength and have relatively little in the way of blood vessels associated with them .This means they are slow to repair themselves. Over a period of time, if the Achilles tendons’ capacity for repair is continually exceeded, structural changes will occur. These changes may onset rapidly after periods of unaccustomed activity, such as with Achilles tendonitis. These symptoms and structural changes, may take longer to manifest themselves as in the case of Achilles tendonosis. Not all people are equally susceptible to these type of soft tissue problems. Some people’s Achilles genes are just better than others.