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|Classification and external resources|
|Classification and external resources|
Plantar fasciitis (also known as plantar fasciopathy or jogger's heel) is a common painful disorder affecting the heel and underside of the foot. It is a disorder of the insertion site of ligament on the bone and is characterized by scarring, inflammation, or structural breakdown of the foot's plantar fascia. It is often caused by overuse injury of the plantar fascia, increases in exercise, weight or age. Though plantar fasciitis was originally thought to be an inflammatory process, newer studies have demonstrated structural changes more consistent with a degenerative process. As a result of this new observation, many in the academic community have stated the condition should be renamed plantar fasciosis.
Plantar fasciitis is the most common injury of the plantar fascia and is the most common cause of heel pain. Approximately 10% of people have plantar fasciitis at some point during their lifetime. It is commonly associated with long periods of standing and is much more prevalent in individuals with excessive inward rolling of the foot, which is seen with flat feet. Among non-athletic populations, plantar fasciitis is associated with obesity and lack of physical exercise.
The heel pain characteristic of plantar fasciitis is usually felt on the bottom of the heel and is most intense with the first steps of the day. Individuals with plantar fasciitis often have difficulty with dorsiflexion of the foot, an action in which the foot is brought toward the shin. This difficulty is usually due to tightness of the calf muscle or Achilles tendon, the latter of which is connected to the back of the plantar fascia. Most cases of plantar fasciitis resolve on their own with time and respond well to conservative methods of treatment.
When plantar fasciitis occurs, the pain is typically sharp and usually unilateral (70% of cases) heel pain worsened by bearing weight on the heel after long periods of rest. Individuals with plantar fasciitis often report their symptoms are most intense during their first steps after getting out of bed or after prolonged periods of sitting. Improvement of symptoms is usually seen with continued walking. Numbness, tingling, swelling, or radiating pain are rarely reported symptoms.
If the plantar fascia continues to be overused in the setting of plantar fasciitis, the plantar fascia can rupture. Typical signs and symptoms of plantar fascia rupture include a clicking or snapping sound, significant local swelling, and acute pain in the sole of the foot.
Identified risk factors for plantar fasciitis include excessive running, standing on hard surfaces for prolonged periods of time, high arches of the feet, the presence of a leg length inequality, and flat feet. The tendency of flat feet to excessively roll inward during walking or running makes them more susceptible to plantar fasciitis. Obesity is seen in 70% of individuals who present with plantar fasciitis and is an independent risk factor. Studies have suggested that there is a strong association between an increased body mass index and the development of plantar fasciitis in the non-athletic population; this association between weight and plantar fasciitis has not been observed in the athletic population. Achilles tendon tightness and inappropriate footwear have also been identified as significant risk factors.
The cause of plantar fasciitis is poorly understood and is thought to likely have several contributing factors. The plantar fascia is a thick fibrous band of connective tissue that originates from the medial tubercle and anterior aspect of the heel bone. From there, the fascia extends along the sole of the foot before inserting at the base of the toes, and supports the arch of the foot.
Originally, plantar fasciitis was believed to be an inflammatory condition of the plantar fascia. However, within the last decade, studies have observed histological changes indicating that plantar fasciitis is actually due to a noninflammatory structural degeneration of the plantar fascia rather than an inflammatory process. Due to this shift in thought about the underlying mechanisms in plantar fasciitis, many in the academic community have stated that the condition should be renamed plantar fasciosis. The structural breakdown of the plantar fascia is believed to be the result of repetitive microtrauma. Histologic examination of the plantar fascia often shows myxomatous degeneration, connective tissue calcium deposits, and disorganized collagen fibers.
Disruptions in the plantar fascia's normal mechanical movement during standing and walking (known as the Windlass mechanism) are thought to contribute to the development of plantar fasciitis by placing excess strain on the calcaneal tuberosity. Other studies have also suggested that plantar fasciitis is not actually due to inflamed plantar fascia, but may be a tendon injury involving the flexor digitorum brevis muscle located immediately deep to the plantar fascia.
The diagnosis of plantar fasciitis is usually made by a health care provider after consideration of a person's presenting history, risk factors, and clinical examination. Tenderness to palpation along the inner aspect of the heel bone on the sole of the foot may be elicited during the physical examination. The foot may have limited dorsiflexion due to tightness of the calf muscles or the Achilles tendon. Dorsiflexion of the foot may elicit the pain due to stretching of the plantar fascia with this motion. Diagnostic imaging studies are not usually needed to diagnose plantar fasciitis. However, in certain cases a physician may decide imaging studies (such as X-rays, diagnostic ultrasound or MRI) are warranted to rule out serious causes of foot pain. Other diagnoses that are typically considered include fractures, tumors, or systemic disease if plantar fasciitis pain fails to respond appropriately to conservative medical treatments. Bilateral heel pain or heel pain in the context of a systemic illness may indicate a need for a more in-depth diagnostic investigation. Diagnostic tests such as a CBC or serological markers of inflammation, infection, or autoimmune disease such as C-reactive protein, erythrocyte sedimentation rate, anti-nuclear antibodies, rheumatoid factor, HLA-B27, uric acid, or Lyme disease antibodies may also be obtained. Neurological deficits may prompt an investigation with electromyography to evaluate for damage to the nerves or muscles.
Lateral view x-rays of the ankle are the recommended first-line imaging modality to assess for other causes of heel pain such as stress fractures or bone spur development. Plantar fascia aponeurosis thickening at the heel greater than 5 millimeters as demonstrated by ultrasonography is consistent with a diagnosis of plantar fasciitis. Authors have noted that medical imaging is not routinely needed as it can be expensive and does not typically change how plantar fasciitis is managed. Findings on imaging such as plantar aponeurosis thickening may be absent in symptomatic individuals or present in asymptomatic individuals thereby limiting the utility of such observations. An incidental finding associated with this condition is a heel spur, a small bony calcification on the calcaneus (heel bone), which can be found in up to 50% of those with plantar fasciitis. In such cases, it is the underlying plantar fasciitis that produces the heel pain, and not the spur itself. The condition is responsible for the creation of the spur though the clinical significance of heel spurs in plantar fasciitis remains unclear.
The differential diagnosis for heel pain is extensive and includes pathological entities including, but not limited to the following: calcaneal stress fracture, calcaneal bursitis, osteoarthritis, spinal stenosis involving the nerve roots of lumbar spinal nerve 5 (L5) or sacral spinal nerve 1 (S1), calcaneal fat pad syndrome, seronegative spondyloparthopathies such as reactive arthritis, ankylosing spondylitis, or rheumatoid arthritis (more likely if pain is present in both heels), plantar fascia rupture, and compression neuropathies such as tarsal tunnel syndrome or impingement of the medial calcaneal nerve.
A determination about a diagnosis of plantar fasciitis can usually be made based on a person's medical history and physical examination. In cases in which the physician suspects fracture, infection, or some other serious underlying condition, an x-ray may be used to make a differential diagnosis. However, and especially for people who stand or walk a lot at work, x-rays should not be used to screen for plantar fasciitis unless imaging is otherwise indicated as using it outside of medical guidelines is unnecessary health care.
Most cases (90%) of plantar fasciitis are self-limited and will improve within the span of six months with conservative treatment or within the span of a year regardless of treatment. Many treatments have been proposed for the treatment of plantar fasciitis. The effectiveness of most of these treatments has not been adequately investigated and consequently there is little evidence to support recommendations for such treatments. First-line conservative approaches include rest, heat, ice, calf-strengthening exercises, techniques to stretch the calf muscles, achilles tendon, and plantar fascia, weight reduction in the overweight or obese, and nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen. NSAIDs are commonly used to treat plantar fasciitis, but fail to resolve the pain in 20% of people.
Extracorporeal shockwave therapy (ESWT) is an effective treatment modality for plantar fasciitis pain unresponsive to conservative nonsurgical measures for at least three months. Evidence from meta-analyses suggests significant pain relief lasts up to one year after the procedure. However, debate about the therapy's efficacy has persisted. ESWT can be performed with or without anesthesia though studies have suggested that the therapy is less effective when anesthesia is administered. Complications from ESWT are rare and typically mild when present. Known complications of ESWT include the development of a mild hematoma or an ecchymosis, redness around the site of the procedure, or migraine.
Corticosteroid injections are sometimes used for cases of plantar fasciitis refractory to more conservative measures. The injections may be an effective modality for short-term pain relief up to one month, but studies failed to show effective pain relief after three months. Notable risks of corticosteroid injections for plantar fasciitis include plantar fascia rupture, skin infection, nerve or muscle injury, or atrophy of the plantar fat pad. Custom orthotic devices have been demonstrated as an effective method to reduce plantar fasciitis pain for up to 12 weeks. The long-term effectiveness of custom orthotics for plantar fasciitis pain reduction requires additional study. Orthotic devices and certain taping techniques are proposed to reduce pronation of the foot and therefore reduce load on the plantar fascia resulting in pain improvement.
Another form of treatment is plantar iontophoresis, a technique which involves applying anti-inflammatory substances such as dexamethasone or acetic acid topically to the foot and transmitting these substances through the skin with an electrical current. Moderate evidence exists to support the use of night splints for 1–3 months to relieve plantar fasciitis pain that has persisted for six months. The night splints are designed to position and maintain the ankle in a neutral position thereby passively stretching the calf and plantar fascia overnight during sleep. Other treatment approaches may include supportive footwear, arch taping, and physical therapy.
Plantar fasciotomy is often considered after conservative treatment has failed to resolve the issue after six months and is viewed as a last resort. Minimally invasive and endoscopic approaches to plantar fasciotomy exist but require a specialist who is familiar with certain equipment. The availability of these surgical techniques is currently limited. A 2012 study found that 76% of patients who underwent endoscopic plantar fasciotomy had complete relief of their symptoms and had few complications (level IV evidence). Heel spur removal during plantar fasciotomy has not been found to improve the surgical outcome. Plantar heel pain may occur for multiple reasons and release of the lateral plantar nerve branch may be performed alongside the plantar fasciotomy in select cases. Possible complications of plantar fasciotomy include nerve injury, instability of the medial longitudinal arch of the foot, fracture of the calcaneus, prolonged recovery time, infection, rupture of the plantar fascia, and failure to improve the pain. Coblation surgery has recently been proposed as alternative surgical approaches for the treatment of recalcitrant plantar fasciitis.
Botulinum Toxin A injections as well as similar techniques such as platelet-rich plasma injections and prolotherapy have recently garnered attention as potentially effective methods to treat plantar fasciitis heel pain. However, recent studies failed to demonstrate botulinum toxin A's superiority to placebo and did not find platelet-rich plasma injections to be a more effective treatment than corticosteroid injections for plantar fasciitis.
Dry needling is a treatment being researched for treatment of plantar fasciitis. A systematic review of available research found limited evidence of efficacy, due to the poor quality of the available studies.
Plantar fasciitis is the most common type of plantar fascia injury and is the most common reason for heel pain, responsible for 80% of cases. The condition tends to occur more often in women, military recruits, older athletes, the obese, and young male athletes. Plantar fasciitis is estimated to affect 1 in 10 people at some point during their lifetime and most commonly affects people between 40-60 years of age. In the United States alone, more than two million people receive treatment for plantar fasciitis. The cost of treating plantar fasciitis in the United States is estimated to be $284 million each year.