The Achilles tendon is the largest tendon in the body. It connects the calf muscles to the heel and is active during almost all activities including walking, jumping, and swimming. This dense tendon can withstand large forces, but can become inflamed and painful during periods of overuse. Pain results from inflammation (tendonitis) or a degenerating tendon (tendinosis). Achilles tendon pathologies include rupture and tendonitis. Many experts now believe, however, that tendonitis is a misleading term that should no longer be used, because signs of true inflammation are almost never present on histologic examination. Instead, the following histopathologically determined nomenclature has evolved. Paratenonitis: Characterized by paratenon inflammation and thickening, as well as fibrin adhesions. Tendinosis: Characterized by intrasubstance disarray and degeneration of the tendon.
The majority of Achilles tendon injuries are due to overuse injuries. Other factors that lead to Achilles tendonitis are improper shoe selection, inadequate stretching prior to engaging in athletics, a short Achilles tendon, direct trauma (injury) to the tendon, training errors and heel bone deformity. There is significant evidence that people with feet that role in excessively (over-pronate) are at greater risk for developing Achilles tendinitis. The increased pronation puts additional stress on the tendon, therefore, placing it at greater risk for injury.
The symptoms associated with Achilles tendonitis and tendonosis include, Pain-aching, stiffness, soreness, or tenderness-within the tendon. This may occur anywhere along the tendon?s path, beginning with the tendon?s attachment directly above the heel upward to the region just below the calf muscle. Often pain appears upon arising in the morning or after periods of rest, then improves somewhat with motion but later worsens with increased activity. Tenderness, or sometimes intense pain, when the sides of the tendon are squeezed. There is less tenderness, however, when pressing directly on the back of the tendon. When the disorder progresses to degeneration, the tendon may become enlarged and may develop nodules in the area where the tissue is damaged.
Examination of the achilles tendon is inspection for muscle atrophy, swelling, asymmetry, joint effusions and erythema. Atrophy is an important clue to the duration of the tendinopathy and it is often present with chronic conditions. Swelling, asymmetry and erythema in pathologic tendons are often observed in the examination. Joint effusions are uncommon with tendinopathy and suggest the possibility of intra-articular pathology. Range of motion testing, strength and flexibility are often limited on the side of the tendinopathy. Palpation tends to elicit well-localized tenderness that is similar in quality and location to the pain experienced during activity. Physical examinations of the Achilles tendon often reveals palpable nodules and thickening. Anatomic deformities, such as forefoot and heel varus and excessive pes planus or foot pronation, should receive special attention. These anatomic deformities are often associated with this problem. In case extra research is wanted, an echography is the first choice of examination when there is a suspicion of tendinosis. Imaging studies are not necessary to diagnose achilles tendonitis, but may be useful with differential diagnosis. Ultrasound is the imaging modality of first choice as it provides a clear indication of tendon width, changes of water content within the tendon and collagen integrity, as well as bursal swelling. MRI may be indicated if diagnosis is unclear or symptoms are atypical. MRI may show increased signal within the Achilles.
There is insufficient evidence from randomised controlled trials to determine which method of treatment is the most appropriate for the treatment of acute or chronic Achilles tendonitis. The patient should abstain from aggravating activities, but with a minimum of rest in order to preserve overall fitness. Possible treatments are non-steroidal anti-inflammatory drugs (NSAIDs), ice, rest, increased warm-up/stretching exercises, physiotherapy and heel lifts (orthotic devices - used on both sides to prevent a gait imbalance). Other treatments evaluated in a Cochrane review were heparin, steroid injections, glycosaminoglycan sulfate, Actovegin?, and topical laser treatment. There was no clear evidence of benefit from these. Casting is an option for resistant Achilles tendonitis. Drugs - analgesics and NSAIDs. Surgery is sometimes used for resistant Achilles tendonitis, but usually as a last resort. Other recently reported treatments include continuing sporting activity in conjunction with rehabilitation, low-energy shock wave therapy and topical glyceryl trinitrate .
Surgery is considered when non-operative measures fail. Patient compliance and postoperative management is an important aspect of the operative management to prevent ankle stiffness or recurrence of the symptoms. Surgery usually requires a removal of the damaged tissue (debridement) and meticulous repair of the tendon. Post-operative immobilization is required, followed by gradual range of motion and strengthening exercises start. It may require 6 months for the full recovery. Some known complication are recurrence, stiffness of the ankle and deep vein thrombosis.
Regardless of whether the Achilles injury is insertional or non-insertional, a great method for lessening stress on the Achilles tendon is flexor digitorum longus exercises. This muscle, which originates along the back of the leg and attaches to the tips of the toes, lies deep to the Achilles. It works synergistically with the soleus muscle to decelerate the forward motion of the leg before the heel leaves the ground during propulsion. This significantly lessens strain on the Achilles tendon as it decelerates elongation of the tendon. Many foot surgeons are aware of the connection between flexor digitorum longus and the Achilles tendon-surgical lengthening of the Achilles (which is done to treat certain congenital problems) almost always results in developing hammer toes as flexor digitorum longus attempts to do the job of the recently lengthened tendon. Finally, avoid having cortisone injected into either the bursa or tendon-doing so weakens the tendon as it shifts production of collagen from type one to type three. In a recent study published in the Journal of Bone Joint Surgery(9), cortisone was shown to lower the stress necessary to rupture the Achilles tendon, and was particularly dangerous when done on both sides, as it produced a systemic effect that further weakened the tendon.