The Achilles tendon is a strong tendon that connects the calf muscles to the heel. The calf is formed by two muscles: the underlying soleus muscle and the thick outer gastrocnemius muscle. When they contract, they pull on the Achilles tendon causing your foot to point down (plantar flexion)and helping you raise up on your toes. This powerful muscle group helps when you sprint, jump, or climb. With aging and overuse, the Achilles tendon is subject to degeneration within the substance of the tendon. The term degeneration means that wear and tear occurs in the tendon over time and leads to a weakening of the tendon. Degeneration in a tendon usually shows up as a loss of the normal arrangement of the fibers of the tendon. Tendons are made up of strands of a material called collagen (think of a tendon as similar to a nylon rope with the strands of collagen being the nylon strands). Some of the individual strands of the tendon become jumbled due to the degeneration, other fibers break, and the tendon loses strength. The healing process in the tendon can cause the tendon to become thickened as scar tissue tries to repair the tendon. This process can continue to the extent that a nodule forms within the tendon. This condition is called tendinosis. The area of tendinosis in the tendon is weaker than normal tendon and is usually painful.
EPIDEMIOLOGY & DEMOGRAPHICS
PREDOMINANT AGE: 30 to 55 yr
PHYSICAL FINDINGS & CLINICAL PRESENTATION
Injury often occurs during an activity that puts great stress on the tendon. Sudden “pop” is often felt followed by weakness and swelling.
• Patient walks flat-footed and is unable to stand on the ball of the foot.
• Tenderness and hemorrhage are present at the site of injury, and a sulcus is usually palpable but may be obscured by an organizing clot if the examination is delayed.
• Although active plantar flexion is usually lost, some plantar flexion occasionally remains because of the activity of the other posterior compartment muscles.
• Thompson’s test is usually positive. Test measures plantar flexion of the foot when the calf is squeezed with the patient kneeling on a chair; normal foot plantarflexes with calf compression, but movement is absent when tendo Achillis is ruptured.
• Excessive passive dorsiflexion of the foot is also present on the injured side.
• Relative hypovascularity predisposing to tendon rupture in several tendons (Achilles, biceps, and supraspinatus)
• With advancing age, vascular supply to the tendon further compromised
• Repetitive trauma leading to degeneration of this critical area and weakness
• Rupture of tendo Achillis usually 2.5 to 5 cm from the insertion of the tendon into the os calcis
• Most common causative event leading to rupture: sudden dorsiflexion of the plantar flexed foot (landing from a height) or sudden pushing off with the weight on the
• Incomplete (partial) tendo Achillis rupture
• Partial rupture of gastrocnemius muscle, often medial head (previously thought to be “plantaris tendon rupture”)
• Clinical diagnosis of tendo Achillis rupture is usually obvious.
• If bony injury is suspected, plain roentgenograms are indicated.
• Other studies are usually unnecessary.
• Early referral is necessary for surgical repair.
• If surgery is contraindicated, a short leg cast applied with the foot in equinus may allow healing.
• In cases of neglected rupture, reconstruction is usually indicated.
• Prognosis for recovery after surgical repair of the acute rupture is good, but recurrence is not uncommon regardless of treatment.
• Tendo Achillis must be protected from excessive activity for up to 1 yr.
• Results of reconstruction for neglected cases are worse than with primary repair.
Achilles tendon rupture
Achilles tendon rupture refers to the loss of continuity of the tendo Achillis, usually from attrition. Achilles tendon ruptures are very debilitating injuries to the ankle. These injuries can occur to the adult population outside of sports, but it is unfortunately not uncommon in athletes. Most commonly it involves athletes in their thirties. Usually the injury involves some sort of running event, such as a sudden stop or start or a change of direction. It is very common to hear an athlete say that he felt like he had been stabbed or shot in the back of the ankle. Athletes often describe feeling or hearing a loud pop. Often they think that someone hit or kick them in the back of the ankle only to turn around and see that no one is there. It is very painful, and the athlete usually has tremendous difficulty walking, let alone playing, immediately after the injury.