Achilles tendon injuries: tendinopathy and rupture

What are Achilles tendon injuries, and what causes them?

The Achilles is the largest tendon in the body. It runs down the back of the lower leg and attaches to the heel bone, and it transmits the force of the calf muscles when you walk, run, climb stairs or rise onto your toes.

Swipe sideways to see the whole drawing.

A stretch of the tendon roughly 2 to 6 centimeters above the heel bone has a limited blood supply and is especially prone to injury.^[1]

Two different problems are common:

• Tendinopathy is irritation and degeneration of the tendon from repetitive load. It occurs in the middle of the tendon (midportion, or “noninsertional”) or where the tendon attaches to the heel bone (insertional; a bump on the heel bone can contribute, see Haglund deformity). Insertional problems are often linked to a tight calf and, in some people, to a prominent bump on the back of the heel bone (Haglund deformity).^[4]
• Rupture is a partial or complete tear, typically after a forceful push-off, sudden acceleration, a jump, a fall, or a stumble.^[5]

Certain medicines can also weaken the tendon, including corticosteroids and some antibiotics, and this is one reason to raise any recent medicines when you are evaluated.^[5]

Symptoms

Tendinopathy: morning stiffness and pain along the tendon or at its attachment to the heel, pain that builds with activity, thickening of the tendon, and swelling that persists through the day.^[4]

Rupture: a sudden stabbing pain at the back of the ankle or calf, often with a pop or snap, swelling between the heel and the calf, and difficulty walking or rising on the toes.^[5]

How it’s evaluated

For tendinopathy, the examination locates the painful part of the tendon, checks calf flexibility and strength, and considers footwear and training changes. Imaging is not always needed; X-rays or ultrasound and MRI can help when the diagnosis is uncertain or when a surgical plan is being made.^[3,1]

For a suspected rupture, a hands-on examination by a foot and ankle surgeon usually confirms the diagnosis by finding a gap in the tendon and weak push-off; MRI is used in some cases.^[5]

Treatment of tendinopathy

Non-surgical care is the mainstay, and it includes:

• A structured exercise program, guided by a physical therapist, that gradually loads the tendon and calf muscles. Clinical practice guidelines for midportion Achilles tendinopathy are built around exercise-based physical therapy.^[3]
• Activity and footwear changes, heel lifts or supportive shoes, night splints and anti-inflammatory medicine for some people.^[4]
• Shockwave therapy, for which evidence in insertional tendinopathy favors shockwave, alone or combined with eccentric exercise.^[7]

A caution about injections. Cortisone injections into the Achilles tendon are not recommended because they can lead to rupture.^[4] A Cochrane review of injection therapies for Achilles tendinopathy found low-quality evidence of no important difference from control on function, and the only major adverse event was a rupture in a trial of corticosteroid injections.^[8]

If symptoms persist after about six months of well-executed non-surgical care, surgery may be discussed. Options include removing damaged tendon tissue (debridement), lengthening the calf muscle (gastrocnemius recession), and, for insertional problems, treating the heel bump. Recovery can take many months, and some people (20% to 30%) continue to have pain after surgery.^[4]

Treatment of a rupture

There are two approaches, and both work best with a structured rehabilitation program.^[5,6]

• Non-surgical treatment uses a cast, walking boot or brace to hold the tendon while it heals, followed by physical therapy. It avoids the risks of surgery, but is generally associated with a higher rate of a second rupture.^[5]
• Surgery repairs the torn ends of the tendon. It is generally recommended for active people, because it is associated with a lower chance of re-rupture and better push-off strength.^[5]

A large meta-analysis of 10 randomized trials and 19 observational studies quantified the trade-off. Re-rupture occurred in 2.3% of people treated with surgery and 3.9% of those treated without it. Complications, mainly infection, were more common with surgery (4.9% compared with 1.6%). Where non-surgical care included accelerated rehabilitation with early movement, the difference in re-rupture was no longer statistically significant. The authors concluded that re-rupture rates were low and the differences between treatments small.^[6]

Among surgical techniques, a meta-analysis of randomized trials compared open repair with minimally invasive repair and found similar functional scores (AOFAS 94.8 with open repair and 95.7 with minimally invasive repair).^[9] See Achilles tendon repair.

When to seek care

Consider an evaluation if heel or Achilles pain has lasted more than a few weeks, if the tendon feels thickened, or if pain limits walking or exercise.