Heel pain is a common and frequent disease in clinic, this article is based on the article Plantar and Medial Heel Pain: Diagnosis and Management in AAOS in 2014, combined with the rest of the literature, together to learn about the five kinds of diseases that are easy to cause heel pain, and the pressure and pain points and localization of the five kinds of heel pain are shown in Figure 1. The pressure points and localization of the five heel pain disorders are shown in Figure 1: ① heel pad atrophy ② plantar fasciitis ③ Baxter’s nerve entrapment syndrome ④ compression fracture of the heel bone ⑤ ankle canal syndrome Plantar fasciitis 1. Especially in the first metatarsophalangeal joint, dorsiflexion increases the tension of the plantar fascia and the plantar longitudinal arch. In turn, it is inherently inelastic and only lengthens by about 4%. The disease is mostly caused by repeated small trauma and excessive tension. Recently, it has been recognized as a non-inflammatory reaction and is more appropriately referred to as “plantar fascia degeneration”. Reduced ankle dorsiflexion due to tension on the Achilles tendon or gastrocnemius muscle is also associated with the development of plantar fasciitis. Obesity, excessive weight bearing, and other independent risk factors include age, shoe discomfort, overtraining, and decreased talar joint mobility. High arches and flat feet are also important causes of plantar fasciitis. 2. Pathology: Mucinous degeneration of collagen fibers, hypertrophy and calcification of vascular fibroblasts, and infiltration of inflammatory cells such as polymorphonuclear leukocytes, lymphocytes, and macrophages are rarely reported. 3. Clinical manifestations: patients often feel the initial pain, that is, the first step in the morning or after a long period of rest is more obvious, walking a few steps after the pain is relieved, but with the growth of walking time or standing time, the pain is aggravated. The pain is sharp and not radiating. 4. Physical examination: localized tenderness around the calcaneal tuberosity, tenderness along the fascia, more pronounced when the plantar fascia is tense (Figure 2), e.g., when the ankle is dorsiflexed. Figure 2 Excessive dorsiflexion of the first bunion can lead to excessive pulling of the plantar fascia, causing pain. The finger shows a tense plantar fascia. Clin J Sport Med. 2004 5. Diagnosis: Weight-bearing plain films of the foot are necessary to detect bone spurs and calcifications, however, autopsy has shown that bone spurs tend to be concentrated at the initiation of the phalangeal flexors rather than at the painful plantar fascia. 6. Treatment: In all cases, the mainstay of treatment should be non-surgical, rest, functional therapy, self-stretching exercises, heel pads, corrective devices, ice, NSAIDs, and weight loss. Barefoot activities as well as ill-fitting footpads and others are not recommended. Shoes that restore the arch of the foot help reduce first metatarsophalangeal joint dorsiflexion and help reduce the maximum tension in the plantar fascia. plantar fascia stretching was more effective compared to Achilles tendon stretching at 8 weeks. However, the results were fair at 2-year follow-up. Other treatments include: nighttime immobilization, prescription medications, corrective devices, and immobilization. Among the effects of immobilization are: prevention and correction of the position of the plantar fascia and gastrocnemius muscle. As well as applying corrective devices. Only a small percentage require the use of local injectable medications and extracorporeal ultrasound therapy. Local steroid injections have proven to be effective in the short term but not in the long term. Side effects include tearing of the plantar fascia, not only as an isolated complication, but also arch tension, lateral and dorsal midfoot tension, lateral plantar nerve dysfunction, stress fractures, and hammertoe deformity. It also includes: localized skin and fat atrophy, localized redness, and damage to surrounding blood vessels and nerves. Leads to hyperglycemia, tendon damage, infection, and facial flushing. ESWT: The use of sound waves to eliminate the inflammatory response could theoretically lead to neovascularization and repair. However there is no conclusive evidence that it is significantly more effective than placebo for. Pulsed radiation electromagnetic field therapy, botulinum toxin type A, and PRP therapy are not effective. Surgical treatment: limited to fasciotomy rather than removal of the spur. Endoscopy has attracted increasing attention over the past few decades due to its short recovery time, with an efficiency rate of 76%. For patients with gastrocnemius muscle atrophy, gastrocnemius muscle release can be used, with 81% of patients experiencing pain relief. Preventive and rehabilitative training includes: 1, release of fascia and muscle 2, stretching fascia and muscle 3, strengthening muscle strength training 4, neuromuscular control exercises. Heel pad atrophy 1. Causes: The heel pad is a piece of fat-rich tissue below the heel bone. This disease occurs in people over 50 years old, due to the loss of water, collagen and elasticity, resulting in atrophy of the heel pad. 2. Clinical manifestations: the pain is mostly deep, non-radioactive and concentrated in the central weight-bearing part of the calcaneal tuberosity. It is easy to be misdiagnosed as plantar fasciitis, which is easily induced by walking barefoot or on hard surfaces, and is alleviated by less walking. The plantar aspect of the calcaneal tubercle is prone to tenderness, which correlates with the degree of swelling. The pain is usually not related to the ankle joint, toe mobility or compression of the nodes. 3. Diagnosis: Lateral radiographs of the heel bone can be used to measure the thickness of the heel pad (Fig. 3), and MRI is not necessary, but it can indicate swelling and atrophy of the heel pad. Figure 3 Lateral image of the heel bone: AB represents the level of the skin, CD represents the level of the heel tuberosity, EF is the line between the two, and its length represents the thickness of the heel pad, this figure is quoted from Somchal Prichasuk.JBJS.1994 4. Treatment: NSAIDs, suitable shoes, special orthotic supports, silicone cups. As the disease is mostly caused by mechanical reasons, reduction of compression and weight bearing is an effective method. Local corticosteroid injections should be avoided as they tend to cause further atrophy in the long term. Surgery is also not recommended, and there is no effective way to dispose of or replace the heel cushion with a new one. Instead, it tends to cause other complications such as skin necrosis. Baxter’s nerve entrapment syndrome 1. Cause: The first branch of the lateral plantar nerve, the only nerve located under the bunion and short toe flexor muscles, and at the same time on the square muscle. It innervates the hallux valgus, short toe flexor, little finger abductor, as well as the lateral plantar skin, heel periosteum, and sensation along the plantar ligament. Areas of vulnerability to entrapment (Figure 4): 1. Underneath the bunion abductor muscle 2. Where the nerve passes through the medial calcaneal tuberosity. Figure 4 Two points where the Baxter nerve is susceptible to entrapment: 1. Between the abductor halluces, flexor digitorum brevis, and plantaris plantae. 2. Before the nerve passes around the medial calcaneal tuberosity. 3. Before the nerve passes through the medial calcaneal tuberosity. 4. When the nerve bypasses the anterior aspect of the medial calcaneal tuberosity (MCT) 2. Clinical manifestations: The pain is mostly located in the anterior 4-5 cm of the heel bone or in the distal aspect of the calcaneal tuberosity, and the pain is mostly a blazing pain radiating along the lateral plantar surface. It mostly coexists with plantar fasciitis. Physical examination includes whether the gastrocnemius flounder muscle is atrophied and the line of force in the posterior part of the foot. The symptoms can be exacerbated by valgus due to a lack of strength in the posterior tibialis tendon and inversion due to clubfoot. Lateral plantar pressure is highest when the foot is plantarflexed and pronated. Pain on percussion can be induced. Lateral plantar sensation is diminished in chronic disease. Neurophysiologic mapping can be used to diagnose the presence of nerve entrapment at the site of stenosis. 3. Treatment: Early stages include: rest, ice, NSAIDs, orthotics for abnormal lines of force at the back of the foot, and localized physical therapy. If conservative treatment fails and symptoms persist for 3 months, surgical decompression may be considered. This includes: release of the deep and superficial fascia of the bunion covering the surface of the nerve. And there are conflicting opinions on whether to eliminate the anterior heel osteochondroma. However, for open surgery, 89% of patients have a high satisfaction rate. Stress Fractures of the Achilles 1. CAUSE: Compression fractures of the largest tarsal bone in the body, the heel bone (Fig. 5), are uncommon and occur only after the metatarsals. They occur in athletes, military personnel, and the elderly with osteoporosis. They are often caused by repeated overloading and inconsistent bone resorption and osteogenesis. Figure 5 Compression fracture of the heel bone: arrow in lateral view of the heel bone 2. Clinical manifestations: Pain is severe and diffuse, distributed along the inner and outer sides of the heel bone. It is aggravated by activity and weight bearing, and is not relieved by rest. There is pressure pain along the lateral side of the heel bone, and the heel bone compression test is positive. 3. Diagnosis: Lateral radiographs of the calcaneus may show destruction of the trabeculae of the calcaneus 2-8 weeks after the onset of symptoms, although these images are often considered normal in the early stages of the disease. A sclerotic bone line perpendicular to the normal trabeculae predicts healing of the compression fracture. When pain persists without evidence on plain radiographs, an MRI or bone scan can help make the diagnosis. 4. Treatment: consists of aggressive management with short leg cast immobilization for 4-8 weeks. It also includes VD supplementation and bone density testing. After immobilization, normal activities can be resumed. Prognosis is favorable and surgery is rarely required. Severe malalignment with abnormal lines of force is uncommon and the likelihood of non-healing is low. Ankle canal syndrome 1. CAUSE: Symptoms resulting from compression of the vascular nerve bundle of the posterior tibial nerve within the ankle canal. It is relatively uncommon and easily overdiagnosed. Flatfoot is the most common cause of ankle canal syndrome, due to the tendency of hindfoot valgus and forefoot abduction to cause nerve compression. The remaining causes include fractures, narrowing of the ankle canal space, and tenosynovitis. Systemic inflammatory arthropathies, diabetes mellitus and rheumatoid arthritis. 2. Clinical manifestations and physical examination: the patient’s subjective sensation is vague and difficult to localize, however, the pain and numbness mostly occurs in the ankle joint and the inner and posterior part of the heel, and most of them radiate to the sole of the foot. It is aggravated by prolonged standing and activities. Sensory dullness interferes with sleep. Particularly pronounced compression leads to reduced muscle strength, first in the abductors of the toes and then in the extensors of the little toes. TINEL disease along the ankle canal and irreparable hyperalgesia along the tibial nerve distribution are the most important symptoms. The rest of the stimuli, such as dorsiflexion and stretching of the tibial nerve, also tend to induce lesions. 3. Diagnosis: MRI is important in the diagnosis of tibial nerve compression due to anatomical anomalies and occupations of the ankle canal. Nerve conduction velocity and electromyography are helpful in confirming the diagnosis. However, they are false negative. 4. Treatment: Non-surgical methods include NSAIDs, and immobilization. Specialized orthopedic shoes should be worn in patients with flat feet. Caution should be exercised with local corticosteroid injections as there is a risk of tendon rupture and intravascular injection. Surgery is indicated in patients who have failed non-surgical treatment and have significant valgus, including careful removal of the flexor support band, and removal of the diaphragm under the adductor muscle is recommended for complete release of the medial plantar nerve. Figure 6 All three of the above images suggest an ankle canal tendon sheath cyst occupying (asterisk) and pressing close to the medial plantar nerve (red arrow) and lateral plantar nerve (blue arrow).