Achilles Tendinopathy

The Achilles is the largest tendon in the body and it takes several times your body weight with every stride. When it is overloaded faster than it can adapt, it thickens, stiffens and hurts — a condition called Achilles tendinopathy. It is common in runners, in people who have started a new activity, and in people in their forties and fifties who have done nothing different at all. Most cases are treated with a structured exercise programme rather than surgery, but the programme has to be the right one for the type of tendinopathy, and it takes months, not weeks.

Two types, two treatments

Where the tendon hurts changes what is done about it.

• Insertional tendinopathy affects the point where the tendon attaches to the back of the heel bone. It is often accompanied by a bony prominence on the heel (a Haglund's deformity), an inflamed bursa between bone and tendon, and calcification within the tendon itself. Shoes rub on it, and stretching can make it feel worse rather than better.

• Mid-portion tendinopathy affects the tendon two to six centimetres above the heel bone, in the stretch with the poorest blood supply. The tendon becomes visibly thickened and tender to squeeze. This type responds well to loading exercises.

The word "tendonitis" is still used, but the tendon is not only inflamed but also worn out.

Symptoms

• pain and stiffness in the tendon first thing in the morning, or when getting up after sitting, easing with a few minutes of walking

• pain that returns after activity, or during it as things progress

• a tender thickening in the tendon (mid-portion), or a tender bump at the back of the heel (insertional)

• difficulty with shoes that press on the back of the heel

• reduced power on the affected side when running or going up on tiptoe

Why it happens

The usual story is a change in load: more running, hills or speed work, a new sport, a return to activity after a break, or simply more time on your feet. Underneath that sit the factors that lower the tendon's tolerance: age, a tight or weak calf, a foot that rolls in or a high arch, being overweight, diabetes, some cholesterol and antibiotic medications, and a previous injury. In insertional disease the shape of the heel bone matters too.

How it is assessed

The diagnosis is made by examination — where the tendon is tender, whether it is thickened, how strong and how tight the calf is, and how the foot is shaped. An ultrasound shows the thickened tendon and any tear within it. A weightbearing X-ray of the heel is useful in insertional disease to look at the bony prominence and any calcification. An MRI is often used when surgery is being planned, to map how much of the tendon is diseased, because that changes the operation.

Non-surgical treatment

This is the treatment for the great majority of people, and it works — but only if it is done consistently for three to six months.

• Progressive loading — a supervised programme of heavy, slow calf exercises that builds the tendon's capacity. The classic version is eccentric heel drops; heavier slow-resistance programmes work as well and are easier to stick to. This is the single most important element.

• Managing the load, not stopping — continuing to walk and, where tolerable, to run at a reduced level, guided by pain that settles within 24 hours.

• Heel raises in the shoes — a small lift takes tension off the tendon while it recovers, and is particularly useful in insertional disease.

• Footwear — a soft or open heel counter for insertional disease, so nothing rubs on the bump.

• Shockwave therapy — a course of sessions for tendons that are not responding to loading alone.

• GTN patches — a small nitrate patch worn over the tendon, which improves blood flow and pain in some people.

• High-volume injection — for mid-portion disease, fluid injected under ultrasound guidance around the tendon to strip away the ingrowing vessels and nerves.

A steroid injection is not put into the Achilles. It gives short-term relief but weakens the tendon and can lead to a complete rupture.

Surgery for insertional tendinopathy

The insertional operation deals with all three problems at once. The tendon is partly detached from the heel bone, the calcified and degenerate tissue is cleaned out, the bony prominence is shaved off and the inflamed bursa removed, and the tendon is then reattached to the bone with anchors. Where more than half the insertion is diseased, the reattachment is reinforced with the same tendon transfer. The calf is sometimes lengthened to relieve the pressure on the heelbone.

Surgery for mid-portion tendinopathy

Where months of proper rehabilitation have not settled a mid-portion tendon, surgery removes the diseased tissue. Through an incision beside the tendon, the thickened, degenerate part is cut away and the healthy tendon repaired. If less than about half the tendon is involved, it is repaired side to side. If more than half is diseased, the tendon needs reinforcing: the tendon of a neighbouring muscle — the one that bends the big toe — is often rerouted to share the Achilles' work. The big toe loses a little power, which most people never notice.

Recovery

After either operation the leg is in a plaster for the first two weeks while the wound heals. At the two-week review you move into a walking boot and start putting weight through the leg. A physiotherapist or podiatrist runs a strengthening programme to rehabilitate the calf. Most people are back in ordinary shoes at around two to three months, driving at around eight weeks for a right leg, and running at four to six months. The tendon keeps improving for six to twelve months, and calf strength is the last thing to return.

Surgery is usually a day procedure, or an overnight stay when the operation is later in the day.

Risks

Every operation carries risk. The specific ones here are wound healing problems and infection — the skin over the Achilles is thin and heals slowly, and smoking makes this markedly worse; numbness on the outer side of the foot from the sural nerve, which runs beside the tendon; stiffness; blood clots; rupture of the repaired tendon; and pain that persists. In insertional surgery the reattachment can fail to hold if it is loaded too early, which is why the boot matters.

Dr Janan's approach

Dr Janan Chandrananth is a foot and ankle orthopaedic surgeon who completed fellowship training in Bristol and in Tokyo, the latter under a past president of the Japanese Society for Surgery of the Foot. Achilles problems, from tendinopathy to rupture, are a routine part of his practice.

His approach is to identify which type of tendinopathy you have, because the exercise programme and the operation differ, and to make sure a proper loading programme has been completed before surgery is discussed. Where an operation is needed, the amount of tendon involved on the MRI decides whether a simple debridement is enough or the tendon needs reinforcing.