Contents
Introduction
- The Achilles tendon is the largest tendon in the body. Tendinopathy and rupture can affect both athletes and those with sedentary lifestyles
- Achilles tendinopathy is usually an overuse condition, causing pain, swelling and stiffness of the Achilles tendon. It is common in runners – in long distance runners the lifetime risk is 50%. In other athletes, the lifetime risk is about 25%
- Acute injury to the Achilles tendon usually occurs from sudden acceleration or deceleration
- Symptoms vary from mild, to severe disabling pain that can interfere with normal daily activities
- Treatment involves avoidance of aggravating activities, rest, ice, compression, simple analgesia, as well as stretching and strengthening exercises
- It does not typically cause a lot of inflammation and thus anti-inflammatory medication (NSAIDs) and corticosteroid injections are of little value – in fact corticosteroids are associated with an increased risk of rupture
- Most cases resolve in weeks to months
- There is an increased risk of Achilles tendon rupture during a flare of Achilles tendinopathy – although it is rare because the pain of tendinopathy usually prevents activities that can cause rupture
Aetiology
- Overuse – e.g. in runners, dancers, tennis players, or any individual who does a lot of jumping type activity
- Often associated with an increase in training duration or intensity
- May be due to poor footwear and / or poor technique
- Training on steep slopes
- Cold weather training
- M > F
- More common with increasing age
- Associated with inflammatory arthritis – e.g. ankylosing spondylitis or psoriatic arthritis
- More common in individuals with other chronic conditions
- Hypertension
- Hypercholesterolaemia
- Diabetes Mellitus
- Drugs
- Fluoroquinolones – e.g. ciprofloxacin – known to predispose to Achilles tendinopathy and rupture
- Family history
- 5x increased risk
Pathology
- The Achilles tendon connects the gastrocnemius and soles muscles to the posterior of the calcaneus
- It begins at the mid calf
- It has slightly unusual anatomy – there is not true synovial sheath and instead it is surrounded by a sheath called the paratenon. This is a highly vascular structure and it allows for a sliding action of the tendon inside the paratenon
- The blood supply is least around the mid tendon – defined as the region 2-6cm proximal to the insertion. This is where most cases of tendinopathy occur
- In Achilles tendinopathy there is thickening, inelasticity, scarring and stiffness of the tendon, and sometimes adhesions to the paratenon or other surrounding structures
- The exact mechanism of this is not well understood
Tendinitis vs tendinosis
- Tendinopathy is a term that refers to any pathology of the tendon. This encompasses both tendinitis and tendinopathy
- Tendinitis refers to inflammation of the tendon. More specifically it refers to inflammation of the tendon sheath. Tendons with tendinitis are not structurally affected on a microscopic level, and the tendons themselves are not weakened. Tendinitis can be treated with rest and anti-inflammatories, and is an acute process that should resolve with treatment.
- Tendinosis is a long-term degeneration of a tendon, and damage to the tendon fibers themselves. It is not an inflammatory process. It leads to tendons that are both microscopically and macroscopically (to the naked eye) different in appearance to healthy tendon. Tendons suffering from tendinosis are weakened and pre-disposed to rupture. Tendons have very limited blood supply, and thus have little capacity for healing.
It is believed that in cases of Achilles tendinopathy, short-term cases probably involve only tendinitis, but in longer-term cases there may be a combination of both tendinitis and tendinosis, or tendinosis alone. Tendinitis may lead to tendinosis.
Cases consisting primary of tendinitis will resolve within a period typically of days to weeks. about 95% of cases resolve with conservative management.
Cases of tendinosis can last for several months. About 80% of cases will improve with conservative management.
Presentation
- Pain in the area of the Achilles tendon
- About 60% of cases in the mid-tendon
- About 20% at the insertion
- Pain usually gradual onset and improves with rest
- Be cautious of Achilles tendon rupture in sudden onset pain, or sudden worsening of pain
- May improve with gentle exercise – i.e. walking – and worsen with more strenuous activity
Examination
- Tenderness of the Achilles tendon – either at the site of insertion, or up to 3-4cm proximal to the site of insertion
- Calf raise – will elicit pain
- Ask patient to stand just on the affected leg, and then stand on tip toes on this leg
- ALWAYS check for Achilles tendon rupture – Simmond’s Triad. Ask the patient to lay prone on the couch, with their feet dangling off the end of the bed. Compare both sides. Check:
- Altered “angle of dangle” – in Achilles tendon rupture the affect foot will naturally “dangle” in a more dorsiflexed position than the unaffected side
- Calf squeeze (aka Thomson’s calf squeeze test) – in a normal, intact Achilles tendon, a calf squeeze should cause plantar flexion of the ankle. In Achilles tendon rupture, there will be minimal or no plantar flexion
- Palpable notch or gap in the Achilles tendon at this site of the rupture
Investigations
- Usually a clinical diagnosis
- USS or MRI can be useful to determine rupture or to rule out other differentials if clinical examination is inconclusive
- X-ray may demonstrate calcification of the tendon in up to 60% of cases but is not required for diagnosis
Differential Diagnosis
- Calcaneal Bursitis – most commonly in older patients, usually due to poorly fitting footwear, rubbing around the area of insertion of the Achilles tendon. Tends to resolve more quickly than Achilles tendinopathy with change of footwear, rest and ice.
- Sever’s Disease – aka Calcaneal apophysitis – an overuse injury, usually seen in boys, between ages of 8 and 15. Present with pain in the heel, and can be unilateral or bilateral. Usually pain and tenderness are 1-2cm distal to the insertion of the Achilles tendon. Again, symptoms tend to resolve with cessation of provoking activity and simple conservative measures, within a few weeks.
- Ankle Sprain
- DVT
Management
- Rest – avoid high impact sports (e.g. running and jumping). Encourage patients to stay moderately active (e.g. walking and weight bearing). Complete rest probably prolongs recovery. Increase level of activity in line with pain reduction.
- Analgesia – paracetamol 1g QID recommended. NSAIDs have been shown to reduce the strength of the Achilles tendon after recovery and should be avoided.
- Ice – is useful for analgesia in the early stages. Recommend 10-30 minutes. Less than 10 minutes is not effective and greater than 30 can cause skin damage. Do not put ice directly on skin – bag of peas wrapped in a tea towel works well!
- Exercises – e.g. gentle calf stretches, calf raises. Usually introduced about 1-2 weeks after the onset of pain, after a period of rest. Usually performed daily, and increasing in intensity.
- Physiotherapy to direct exercises and tailor a specific programme to the patient can be useful if not responding to self directed therapy
- Corticosteroid injections – are strongly contraindicated. Although useful in other tendinopathies, in Achilles tendinopathy they increase the risk of rupture
- The earlier treatment is started, the shorter the duration of symptoms
- Some cases become chronic. In these cases, specialist treatments may be attempted:
- Extracorporeal shock-wave therapy – a type of sound wave therapy. Studies prove benefit in cases that have not responded to other treatments. Small risk of causing rupture. Should only be performed after discussion with specialist.
- Autologous blood injection – also occasionally used under specialist supervision. Efficacy is unclear. It is thought that growth factors contained in the blood may stimulate healing.
- Plaster cast – may be useful in difficult to treat cases
- Surgery – sometimes considered as a last resort. Surgery can remove nodules and scarring, and remove adhesions of the tendon capsule. In certain cases, a longitudinal incision is made in the tendon to encourage healing.
References
- Achilles Tendinopathy – Patient.info
- Achilles Tendinopathy and Rupture – Patient.info
- Achilles tendinopathy and tendon rupture – UpToDate
- Achilles Tendinopathy: Advice and Management – Oxford University Hospital NHS Foundation Trust