The Achilles tendon is the largest and most vulnerable tendon in the body. It joins the gastrocnemius (calf) and the soleus muscles of the lower leg to heel of the foot. The gastrocnemius muscle crosses the knee, the ankle, and the subtalar joints and can create stress and tension in the Achilles tendon . Tendons are strong, but not very flexible so they can only so far before they get inflammed and tear or rupture.
The Achilles tendon is most commonly injured by sudden plantarflexion or dorsiflexion of the ankle, or by forced dorsiflexion of the ankle outside its normal range of motion. Other mechanisms by which the Achilles can be torn involve sudden direct trauma to the tendon, or sudden activation of the Achilles after atrophy from prolonged periods of inactivity. Some other common tears can occur from overuse while participating in intense sports. Twisting or jerking motions can also contribute to injury. Fluoroquinolone antibiotics, famously ciprofloxacin, are known to increase the risk of tendon rupture, particularly achilles.
Tendon strain or tendon inflammation (tendonitis) can occur from tendon injury or overuse and can lead to a rupture. Call your doctor if you have signs of minor tendon problems. Minor tenderness and possible swelling increases with activity. There is usually no specific event causing sudden pain and no obvious gap in the tendon. You can still walk or stand on your toes. Acute calf pain and swelling can indicate a tear or partial tear of the Achilles tendon where it meets the calf muscle. You may still be able to use that foot to walk, but you will need to see a specialist such as an orthopedic surgeon. Surgery is not usually done for partial tears. Sometimes special heel pads or orthotics in your shoes may help. Follow up with your doctor to check for tendonitis or strain before resuming activity, because both can increase the risk of tendon rupture. Any acute injury causing pain, swelling, and difficulty with weight-bearing activities such as standing and walking may indicate you have a tear in your Achilles tendon. Seek prompt medical attention from your doctor or emergency department. Do not delay! Early treatment results in better outcome. If you have any question or uncertainty, get it checked.
During the clinical examination, the patient will have significantly reduced ankle plantar flexion strength on the involved side. When the tendon is palpated with one finger on either side, the tendon can be followed from the calcaneus to where it "disappears" in the area of the rupture and to where it then returns 2 to 3 cm proximal to the rupture. If the injury is recent, the patient indicates that her pain is localized at the site of the rupture. The defect eventually fills with blood and edema and the skin over the area becomes ecchymotic.
Non Surgical Treatment
The most widely used method of non-surgical treatment involves the use of serial casting with gradual progression from plantar flexion to neutral or using a solid removable boot with heel inserts to bring the ends of the tendon closer together. The advantage of a solid removable boot is that it allows the patient to begin early motion and is removable. Wide variability exists among surgeons in regards to the period of absolute immobilization, initiating range of motion exercises, and progression of weight bearing status.
While it is possible to treat an Achilles tendon rupture without surgery, this is not ideal since the maximum strength of the muscle and tendon rarely returns. The reason is the ends of the tendon are ruptured in a very irregular manner, almost like the ends of a paint brush. As soon as the tendon ruptures, the calf muscle (gastrocnemius muscle) continues to pull on the tendon and the end of the ruptured tendon pulls back into the leg, which is called retraction. Once the tendon retracts, it is never possible to get sufficient strength back without surgery, because the muscle no longer functions at the correct biomechanical length and is now stretched out. There are patients for whom surgery cannot be performed, in particular, due to existing medical conditions that may add to potential for complications following surgery. For these patients, a specially designed boot that positions the foot correctly and takes the pressure and tension off the muscle and tendon is used. Most importantly, a cast is never used because it causes permanent shrinkage (atrophy) of the calf muscle. The special boot permits pressure on the foot with walking. The boot also has a hinge to permit movement of the ankle. Many studies of Achilles tendon ruptures have shown that this movement of the foot in the boot while walking is ideal for tendon healing. If surgery is not recommended, it is essential to obtain special tests to check that the ends of the tendon are lying next to each other so that healing can occur. The best test to do this is an ultrasound and not an MRI.
Achilles tendon rupture can be prevented by avoiding chronic injury to the Achilles tendon (i.e. tendonitis), as well as being careful to warm up and stretch properly before physical activity. Additionally, be sure to use properly fitting equipment (e.g. running shoes) and correct training techniques to avoid this problem!