The Foot and Ankle Clinic

Achilles Tendonitis

What is achilles tendonitis? | What does achilles tendonitis look like? | Insertional problems of the achilles | Symptoms of achilles tendonitis | Causes of achilles tendonitis | Treatments for achilles tendonitis | Physiotherapy for achilles tendonitis | Orthotic for achilles tendonitis | Shockwave Treatment | How soon should non-operative treatment of achilles tendonitis improve symptoms? | Imaging of the Achilles Tendon I Injecting achilles tendonitis | The surgical treatment of achilles tendonosis | What is the rationale behind the operations? | Post operative course following achilles tendonitis surgical treatment | Achilles Rupture | Return to normal activity after Achilles Tendon surgery | What is a Haglunds deformity? | What Is insertional tendonosis of the achilles? | Treatment for Haglunds deformity/or insertional achilles tendonosis | Non-operative treatment of Haglunds deformity, achilles tendonosis | Operative management of Haglunds deformity and insertional achilles tendonosis


What is Achilles Tendonitis?

Achilles Tendonitis

Achilles Tendonitis

Achilles tendonitis is a degenerative condition of the Achilles tendon.
It is not entirely clear why in one person the tendon will start to degenerate and in another may give lifelong trouble free function.  There are various factors associated with the Achilles tendon degenerating such as body weight, age, repetitive high impact activities and recurrent injuries.  Also highly relevant is the collagen type which any particular person possesses (and there are a number of variations here).

The main chronic clinical conditions which affect the tendon are sub-divided into Achilles tendonitis and Achilles tendinosis.  Achilles tendonitis implies the superficial layers of the tendon only are affected and Achilles tendinosis a deeper problem with the substance of the tendon itself.  Problems of the Achilles can also be classified into those affecting the main substance of the tendon (“the body”) or the insertional area of the tendon into the back of the calcaneus or heel bone (insertional tendonitis or tendinosis of the Achilles tendon).

What does Achilles Tendonitis look like?

What does Achilles Tendonitis look like?


The Achilles tendon can be thought of almost like a tightly packed horse’s tail with many longitudinal Achilles tendon fibres running parallel to each other and backed into an approximately cylindrical structure in its main portion (2).  In a healthy tendon these parallel fibres are easily visible on direct inspection of the tendon.  If the Achilles tendon undergoes a process of degenerative change these well-defined parallel fibres will start to lose their structure.  The tendon starts to look far more amorphous and less distinct (1).  Such structural change within the tendon can just be very limited and difficult to identify clinically.  If things progress however the tendon becomes visibly different with an area of swelling where the structural change of tendinosis has occurred.  In such cases it is usually easy to define normal tendon both above and beneath a central area of degenerative tendon.

The Achilles tendon is surrounded circumferentially by a fine and thin covering known as the paratenon (3) this layer looks something like a sausage skin and its function is predominantly to supply bloods to the tendon and allow a degree of lubrication to the superficial tendon layers.  In Achilles tendonitis it is predominantly this layer that is affected.

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 of a shoe by a bony prominence at the back of the calcaneus (heel bone), which is known as a haglund's deformity.  It is not actually a deformity but just a variation in terms of the normal anatomy at the back part of the heel bone.


Bilateral Hagglunds Deformities      X-Ray Haglunds Deformity

Bilateral Hagglunds Deformities

Alternatively the Achilles tendon may have undergone degenerative change in its insertion.  This usually produces a more diffuse area of swelling across the back of the heel.  Not Infrequently however a bony spur can develop secondarily within the Achilles insertion as a result of the degenerative change.  The phenomenon of bone deposition in chronically degenerate tendons is also seen elsewhere in the body, for example some muscles around the hip and shoulder.


Diffuse thickening of the back of the heel

Symptoms of Achilles Tendonitis/Achilles Tendinosis?

The main symptom of Achilles Tendonitis or Achilles Tendinosis is one of pain.  This remains very well localised to the problematic area of the tendon and may also be associated with swelling.  The symptoms are usually intermittent and may occur initially either during or after periods of increased activity, such as sport.  Symptoms may progress and on occasion will be present also at rest or even at night, producing sleep disturbance.

If the problem is one of a Hagglunds’ deformity with a normal Achilles tendon then the symptoms may exclusively occur in particular shoe wear that compresses the posterior aspect of the heel.  

The symptoms are very similar whatever the specific problem with the Achilles tendon.  On occasion patients with even advanced degenerative Achilles tendon problems may get little in the way of problems initially.

Causes of Achilles Tendonitis ?

Achilles tendons, like all musculoskeletal tissue, are exposed to multiple episodes of minor trauma during function.  Why some Achilles tendons degenerate and others don’t is not clearly defined and the factors producing degenerative change are multifactorial.  Things that are associated with developing Achilles tendinosis are age, sex, weight and usage.  All Achilles tendons are constructed very much for strength and have very little in the way of blood vessels associated with them.  This means they are slow to repair themselves with episodes of minor of chronic repetitive trauma.  Over a period of time, if the Achilles tendon capacity for repair is continuously needed, then structural changes will occur.  These changes may onset rapidly after periods of unaccustomed activity such as Achilles tendonitis.  Not all people are equally susceptible to these types of soft tissue problems.  Some people’s collagen is just better than others..


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