The Achilles tendon is the largest and strongest tendon in the body, joining the calf muscles to the heel bone. Midsubstance Achilles tendonitis (also called noninsertional or midportion) affects the middle of the tendon, roughly 2 to 6 cm above where it joins the heel. This part of the tendon has a poorer blood supply, so it copes less well with heavy or repeated loading.

Although it was historically called Achilles ‘tendinitis’, tissue samples taken at surgery show very little true inflammation. Doctors now usually use the word tendinopathy, because the problem is one of failed healing and gradual wear of the tendon fibres from repeated strain, rather than simple inflammation. This is different from insertional Achilles pain, which occurs right at the heel bone. Seeing a Consultant Foot & Ankle Surgeon such as Mr Matthew Welck in London makes sure the right type is diagnosed and treated.

Midsubstance Achilles tendonitis is common and becoming more common. Some cases come from high-level sport, but far more come from everyday recreational exercise and ‘weekend-warrior’ activity across all adult ages. It mostly affects young and middle-aged adults.

The condition can have a real effect on how you move, your work and your quality of life.

The exact cause of the pain is still not fully understood, and several things probably play a part at the same time. Current thinking includes:

• Long-term overloading and failed healing — repeated strain on the middle of the tendon, where the blood supply is poorer, causes tiny areas of damage that do not heal properly
• New blood vessels and nerves growing into the tendon (neovascularisation) — these abnormal vessels and nerve fibres are thought to be one source of the pain
• Chemical changes — a build-up of certain molecules and inflammatory signals that make the tendon more sensitive
• Plantaris tendon interference — in some people a nearby small tendon (the plantaris) rubs against the Achilles and adds to the pain
• Calf tightness — a tight calf muscle (the gastrocnemius) puts extra strain on the tendon

Because more than one source of pain can be present at the same time, treatment often targets several of them — which is also why there are several different operations for the same condition.

Symptoms vary depending on how active you are, but usually include:

• Pain in the body of the tendon, 2–6 cm above the heel
• Swelling in one spot, with a thickened, tender area you can often feel
• Morning stiffness and stiffness after rest
• Pain when you start exercising that may ease as you warm up, then feel worse afterwards (common in athletes)
• Aching after standing or walking for a long time (more common in less active people)
• Discomfort when you pull your foot upwards, hop, or rise onto the toes of one leg

The diagnosis is mainly made by examining you, with scans to confirm the type and show how much the tendon has changed:

• Examination in clinic — pinpointing tenderness and thickening in the middle of the tendon, and testing for pain on movement and when rising onto your toes
• Ultrasound scan with colour Doppler — shows thickening of the tendon and the abnormal blood flow (neovascularisation) linked with pain, and can be done in clinic while you move the ankle
• MRI scan — shows how much of the tendon is worn or damaged, which helps with planning any surgery

Scans are especially useful because they tell the difference between a tendon that is swollen but still structurally sound and one with more damage inside — that difference guides whether physiotherapy, a smaller procedure or a bigger repair is the right choice.

Treatment without surgery is always tried first and works for most people. Only about one in three people eventually need surgery, and only after at least six months of proper non-surgical treatment.

• Loading exercise programmes (slow, controlled calf exercises) — the mainstay of treatment, gradually loading the tendon to encourage healing. See our downloadable Achilles Tendinopathy exercise guide (PDF)
• Physiotherapy — supervised rehabilitation and calf stretches to ease tightness
• A change of footwear and a heel raise to reduce strain, plus adjusting your activities
• Shockwave therapy in selected cases
• Injections — including high-volume or sclerosing injections, which target the abnormal blood vessels and nerves. The role of PRP (platelet-rich plasma) injections is still debated

Treatment without surgery takes patience — real improvement often takes several months. Surgery is only considered if you have stuck with a proper programme and the pain has still not settled.

Surgery is only for the small number of people whose pain continues despite a lot of non-surgical treatment. Because the exact source of pain varies from person to person, there are several different operations.

Patients preparing for surgery may find our downloadable Preparing for Foot & Ankle Surgery guide (PDF) and the Guide to Risks of Ankle & Hindfoot Surgery (PDF) a helpful next step.

Recovery depends on which procedure is performed. Smaller keyhole procedures such as scraping or a calf release allow a quicker return to activity, while clearing out the tendon with a repair, or an FHL transfer, needs a more protected recovery. Recovery usually involves:

• Early protection in a boot or splint, with how much weight you can put through the leg depending on the operation you have had
• Step-by-step physiotherapy to get your movement back, then to build calf and tendon strength
• A gradual return to walking, then gentle activity, then running and sport

Most people improve steadily over several months. Your physiotherapy programme is tailored to the operation you have had and to your own goals.

Mr Matthew Welck is a Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital (RNOH) Stanmore — a specialist tertiary orthopaedic centre — and Honorary Associate Clinical Professor at UCL.

He runs a specialist practice devoted entirely to foot and ankle problems, with particular expertise in sports injuries, complex reconstruction, revision surgery and total ankle replacement. He has written more than 50 published research papers, has completed two specialist fellowships including training abroad, and remains active in research. Patients come from across London, the UK and overseas.

Patients are seen across North and Central London, with quick access to ultrasound, MRI and weight-bearing CT scans. All of the options are discussed with you, and a plan that suits you is agreed together. Visit matthewwelck.com to learn more.

If you have ongoing Achilles pain, swelling or stiffness that is limiting your activity or sport, seeing a specialist can make a real difference. Being seen early gives you the widest choice of treatments and the best long-term result.

Book a private or NHS consultation with Mr Matthew Welck, Consultant Foot & Ankle Surgeon.

• Email: secretary@matthewwelck.com
• Call: 07547 395 270
• Website: matthewwelck.com