Achilles tendinitis is a lesion of the Achilles tendon at its Achilles stop, the cause of which is not well understood. It can occur not only in athletes but also in middle-aged and elderly people who are not very active. In athletes, Achilles tendinitis may be caused by inadequate preparation for exercise, sudden changes in exercise volume, and frequent activity on uneven or sloped surfaces. The Achilles tendon is subjected to excessive, abnormal, repetitive stresses and micro-tears occur. Non-athlete’s stopping point Achilles tendonitis is usually seen in overweight middle-aged and older women, and may be caused more by degeneration than by overactivity. In addition, abnormalities in the line of force of the foot are also causes of Achilles tendon injury and degeneration. For example, excessive rotation of the foot in front of the Achilles tendon is unbalanced, and the moment of the Achilles tendon increases, which increases the load on the Achilles tendon. The high arch of the foot weakens the role of the foot in absorbing ground stress during walking and increases the stress on the Achilles tendon. Posterior heel pain can also be caused by systemic diseases such as ankylosing spondylitis and gout. In patients with achilles tendinitis, fibromucinous degeneration occurs at the Achilles tendon stop and eventually fibrosis, calcification, thickening of the Achilles tendon, and nodule formation. Stopping point Achilles tendinitis is often combined with changes in other surrounding structures. For example, the posterior superior Achilles nodes may become hypertrophic and irritate the Achilles tendon capsule causing pain. Pain can also be caused by inflammation of the subcutaneous capsule caused by friction between the skin of the protruding area and the shoe upper after wearing narrow or stiff shoes. Since Patrick Haglund first described this lesion in 1928, the posterior superior heel node can become hypertrophic and is also known as Haglund’s deformity. (C) Clinical manifestations Stopping point Achilles tendinitis in athletes is often characterized by pain in the heel during exercise. It usually does not affect daily activities. Non-athlete’s achilles tendinitis may gradually develop pain in the posterior part of the heel. It starts as intermittent pain and may become constant pain. The Achilles tendon stops may be normal or enlarged in appearance, with localized pressure pain. It makes it difficult or painful for the patient to lift the heel with one foot. In a small number of patients, rupture of the Achilles tendon may occur with activity, resulting in a positive Thompson test. Achilles tendon capsulitis usually develops in middle-aged and elderly people who do not exercise much. The typical course of the disease is sudden onset of pain and localized swelling in the posterior heel. The pain may be aggravated by passive dorsiflexion of the ankle joint. Haglund deformity usually occurs in young people. It presents as a posterior lateral protrusion of the heel tuberosity. In the absence of bursitis, there may be no clinical symptoms, and the skin of the protruding bone and the upper of the shoe may rub together, causing localized skin redness and pain. However, in many patients, there is a coexistence of achilles tendonitis, Achilles tendon bursitis and Haglund’s deformity. Laboratory tests, such as blood uric acid and HLA-B27, are performed to determine the presence of gouty arthritis and ankylosing spondylitis. Radiographic manifestations: the loss of the anterior Achilles tendon capsule shadow, widening of the Achilles tendon by more than 9 mm in 2 cm above the bursa, calcification and bone formation at the Achilles tendon attachment can be seen on lateral X-ray. MRI is generally not used as a routine examination. If non-surgical treatment fails and surgical treatment is needed, MRI can clearly show the protrusion of Achilles tendon, bursa and Achilles tuberosity in order to facilitate the design of surgical plan. (D) Treatment 1, non-surgical treatment 95% of patients can achieve better results with non-surgical treatment. (1) For athletes with achilles tendonitis, the amount of exercise should be reduced and running and jumping on ramps or hard surfaces should be avoided. In severe cases, rest or braking may be required for 4-6 weeks. (2) Cold compresses can be used after exercise. (3) Non-steroidal anti-inflammatory and analgesic drugs (NSAIDs). Hormone injections may be used for Achilles tendon bursitis, but do not inject into the Achilles tendon. Patients with gout need to use colchicine, allopurinol, etc. Patients with rheumatoid arthritis need appropriate medical management. (4) Wear soft shoes to reduce the compression of the Achilles tendon stop, and also use the Achilles tendon socks with silicone pads for protection. Soft Achilles tendon protectors can reduce the stress on the Achilles tendon and reduce pain. Heel elevation can also reduce the stress on the Achilles tendon. Orthopedic shoes or foot pads can correct the poor force line of the foot and reduce the stress of the Achilles tendon. (5) Physical therapy and gentle pulling exercises for the Achilles tendon. (6) For non-athlete stopping point Achilles tendonitis, the above non-surgical treatment methods can be tried first. But the general bad activity of middle-aged and old patients, non-surgical treatment is less effective, may need surgery. 2.Surgical treatment Surgical treatment can remove the degenerative and inflammatory tissues of Achilles tendon, bursa and hyperplasia of the posterior superior heel nodes. If the Achilles tendon lesion is large, after removing the lesion, the Achilles tendon will be lost, and the Achilles tendon will be reconstructed and sutured directly to the Achilles node. If the stop cannot be reconstructed, the Achilles tendon needs to be reconstructed with a tendon transfer, such as using the flexor digitorum longus tendon to reconstruct the Achilles tendon.