Enthesitis and Enthesopathy

Enthesitis causes tenderness and pain near inflamed ligaments or tendons.

Enthesopathy is a general term that refers to a disorder affecting the site where tendons, ligaments, or other soft tissues attach to bone, known as the enthesis. Enthesitis, on the other hand, is a specific type of enthesopathy that refers to inflammation of the entheses.

Types of enthesopathy

Enthesopathy is named by the location in the body where it occurs.

• Spinal ankylosing spondylitis is a typical example where inflammation at the entheses causes pain and stiffness in the spine.
• Diffuse idiopathic skeletal hyperostosis (DISH): A condition characterized by the calcification and ossification of ligaments and entheses, leading to stiffness and pain in the spine.

Spinal enthesopathy can lead to the formation of new bone at the entheses, known as syndesmophytes. Over time, these can cause the spine to fuse, which is a characteristic feature of ankylosing spondylitis.

Calcaneal enthesopathy: Calcaneal enthesopathy affects the entheses at the heel bone (calcaneus). Key conditions include:

• Plantar fasciitis: Inflammation at the insertion of the plantar fascia into the calcaneus, causing heel pain.
• Achilles tendon enthesopathy: Inflammation or degeneration at the insertion of the Achilles tendon into the calcaneus. It can lead to pain, swelling, and limited movement in the heel. Chronic stress or repetitive use is often a contributing factor.

Enthesopathy calcaneus:

• This condition specifically refers to enthesopathy at the heel bone. It includes both inflammatory and degenerative changes at the insertion of tendons or ligaments into the calcaneus.
• Overuse, trauma, and systemic inflammatory conditions such as rheumatoid arthritis or psoriatic arthritis can contribute to this disorder.

Achilles tendon enthesopathy:

• This is a type of calcaneal enthesopathy involving the Achilles tendon. It is characterized by pain at the back of the heel, particularly during or after physical activity.
• It can be associated with systemic conditions such as spondyloarthropathies or result from overuse injuries.

Enthesopathy of the knee: Knee enthesopathy affects the entheses around the knee joint. It can involve several structures:

• Patellar tendon: Inflammation or degeneration at the insertion of the patellar tendon into the tibia (tibial tuberosity), commonly seen in conditions such as Osgood-Schlatter disease.
• Quadriceps tendon: Enthesopathy at the insertion of the quadriceps tendon into the patella can lead to pain and dysfunction in the knee joint.

Pelvic enthesopathy: Pelvic enthesopathy involves the entheses around the pelvis, including:

• Ischial tuberosity: This is where the hamstring muscles attach. Enthesopathy here can cause buttock pain, particularly worsened by sitting.
• Iliac crest: This site serves as the insertion point for abdominal and gluteal muscles. Enthesopathy at this location can lead to pain in the pelvis and lower back.

Pelvic enthesopathy is often associated with systemic inflammatory conditions such as ankylosing spondylitis or psoriatic arthritis, where inflammation at the pelvic entheses contributes to overall disease pathology.

Enthesopathy can be caused by injury or diseases. When it affects a single area of the body, it is often due to injury. Conversely, when it affects multiple areas, underlying disorders are more likely to be the cause.

There are several potential causes of enthesitis and enthesopathy, which can be broadly categorized into the following:

Inflammatory arthritides

• Ankylosing spondylitis: A chronic inflammatory disease primarily affecting the spine and sacroiliac joints. Enthesitis is a hallmark of this condition, often seen at the Achilles tendon and plantar fascia.
• Psoriatic arthritis: An inflammatory arthritis associated with psoriasis. Enthesitis is common, particularly at the Achilles tendon, plantar fascia, and around the elbow.
• Reactive arthritis: Follows an infection (often gastrointestinal or genitourinary). Enthesitis often involves the lower limbs, especially the Achilles tendon.
• inflammatory bowel disease (IBD)-related arthritis: Conditions such as Crohn's disease and ulcerative colitis can be associated with enthesitis, typically affecting the lower limbs.

Degenerative conditions

• Osteoarthritis: Degenerative changes in joints can extend to the entheses, causing secondary enthesopathy due to altered biomechanics and increased stress on the attachment sites.

Mechanical stress and overuse

• Repetitive strain injury: Chronic overuse of a joint can lead to microtrauma at the enthesis, causing inflammation. This is common in athletes and individuals with occupations requiring repetitive movements.
• Obesity: Excessive weight can increase mechanical stress on weight-bearing entheses, particularly at the knees and feet.

Trauma

• Acute injury: Direct trauma or injury to an enthesis can lead to inflammation and subsequent enthesitis. Common sites include the Achilles tendon and elbow.
• Chronic microtrauma: Repeated minor injuries can accumulate over time, leading to enthesopathy.

Metabolic and endocrine disorders

• Diabetes mellitus: Poor blood glucose control can lead to abnormal collagen formation and calcification at the entheses, causing pain and inflammation.
• Gout: Uric acid crystal deposition can occur in the entheses, causing inflammation and pain, typically at the Achilles tendon or knees.

Infectious causes

• Direct infection: Bacterial or viral infections can directly infect the entheses, though this is rare. An example is reactive arthritis after a Chlamydia or Salmonella infection.
• Tuberculosis: In rare cases, Mycobacterium tuberculosis can infect the entheses, leading to chronic inflammation.

Genetic factors

• HLA-B27: This genetic marker is strongly associated with ankylosing spondylitis and other spondyloarthropathies, which often present with enthesitis.
• Family history: A family history of spondyloarthropathies or other inflammatory arthritides can increase the risk of developing enthesitis.
• Autoimmune diseases: Autoimmune diseases like psoriatic arthritis, reactive arthritis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis (DISH), and rheumatoid arthritis can cause enthesitis as the immune system attacks tissues within the joints.

Medications

• Fluoroquinolones: Antibiotics in this class can cause tendinitis and enthesitis, particularly affecting the Achilles tendon.
• Steroid use: Long-term steroid use can lead to tendon weakening and increased susceptibility to enthesitis.

Other systemic diseases

• Sarcoidosis: This inflammatory disease can involve the entheses, leading to granulomatous inflammation and pain.
• Systemic lupus erythematosus (SLE): Although less common, SLE can cause enthesitis as part of its widespread inflammatory effects on connective tissue.

Aging

• Age-related changes: Degenerative changes and reduced elasticity in tendons and ligaments with aging can predispose individuals to enthesitis.

Understanding the specific cause of enthesitis or enthesopathy is crucial for targeted treatment and management, as the underlying condition often dictates the therapeutic approach.

Enthesitis and enthesopathy can have similar symptoms because they both involve inflammation or structural changes at the entheses (the sites where tendons and ligaments attach to bone).

Common symptoms

• Pain: Pain is a common symptom of enthesitis and enthesopathy. It can range from mild to severe and is often described as a burning or intense pain in the affected area.
• Stiffness: Stiffness is another common symptom, which can make it difficult to move the affected joint or area.
• Swelling: Swelling is often present in the affected area, which can be accompanied by redness and warmth.
• Tenderness: Tenderness is another common symptom, especially when pressure is applied to the affected area.

Specific symptoms

• Achilles tendinitis: Pain in the back of the heel, which can make it difficult to run or climb stairs.
• Plantar fasciitis: Pain in the bottom of the foot, which can make it difficult to walk or stand.
• Rotator cuff syndrome: Pain in the shoulder, which can make it difficult to lift or rotate the arm.
• Bursitis: Pain and swelling in the joints, which can make it difficult to move the affected joint.
• Fibrosis: Thickening and scarring of soft body tissues, which can lead to permanent changes in the affected area.
• Calcification or ossification: Formation of new bone tissue, which can lead to bone spurs and permanent changes in the affected area.

Other signs and symptoms

• Nail changes: Changes in the fingernails or toenails, such as nail cracking, pitting, or separation from the nail bed.
• Dactylitis: Inflammation of the fingers or toes, which can be painful and make it difficult to move the affected digit.
• Fatigue: Fatigue is a common symptom, especially in individuals with chronic enthesitis.

These symptoms can vary in severity depending on the underlying cause and the extent of inflammation or damage at the enthesis. It's essential to consult a health care professional for an accurate diagnosis and appropriate management.

Enthesitis is usually diagnosed clinically by simple examination by a health care professional. Radiologic testing can sometimes demonstrate calcification or spur formation in the area if the enthesitis is chronic. MRI scanning can highlight inflamed tissues.

Enthesitis and enthesopathy are clinically diagnosed when the following three criteria are met

• Current or recent (within the past two weeks) pain
• Local tenderness
• Pain on resisted motion or traction

Diagnosing enthesitis involves a combination of clinical evaluation, imaging studies, and sometimes laboratory tests.

Clinical evaluation:

• History and physical examination: The doctor will take a detailed medical history and ask about symptoms such as pain, swelling, and stiffness, especially at tendon or ligament attachment sites. Common sites include the Achilles tendon, plantar fascia, and lateral epicondyle.
• Palpation: Tenderness at the enthesis is a key clinical finding. The physician will palpate the entheses to check for pain and swelling.

Imaging studies:

• Ultrasound: This is a sensitive tool for detecting early changes in enthesitis. It can show thickening of the enthesis, erosions, calcifications, and increased blood flow (indicating inflammation).
• Magnetic resonance imaging (MRI): It is useful for visualizing both soft tissue and bone involvement. It can detect bone marrow edema, which is indicative of active inflammation at the enthesis.
• X-rays: While less sensitive to early changes, X-rays can show bone changes such as erosions or new bone formation at the enthesis in chronic cases.

Laboratory tests:

• Inflammatory markers: Blood tests for markers of inflammation, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), may be elevated in cases of enthesitis, although they are not specific.
• HLA-B27: Testing for the HLA-B27 gene can be helpful, particularly if a spondyloarthropathy (a group of inflammatory rheumatic diseases that involve the entheses) is suspected.

Diagnosis of enthesopathy:

Clinical evaluation:

• History and physical examination: Similar to enthesitis, the physician will take a detailed history and perform a physical exam to identify symptoms such as pain, swelling, and functional limitations at the entheses.
• Palpation: The doctor will palpate the affected entheses to identify tenderness and any abnormal changes.

Imaging studies:

• Ultrasound: This can help differentiate between inflammatory and degenerative changes at the enthesis. Ultrasound may show changes such as thickening, calcification, or tears in the tendon or ligament.
• MRI: MRI is particularly useful for distinguishing between different types of enthesopathies. It can show detailed images of soft tissue and bone, including inflammation, edema, and degenerative changes.
• X-rays: X-rays can reveal chronic changes such as calcification, bone spurs, or erosions. They are less useful for detecting early or purely soft tissue changes.

Laboratory tests:

• Inflammatory markers: In cases of inflammatory enthesopathy (such as enthesitis), markers such as CRP and ESR might be elevated.
• Rheumatologic tests: If a systemic inflammatory disease is suspected, additional tests such as rheumatoid factor (RF) or anti-cyclic citrullinated peptide (anti-CCP) antibodies may be performed.

Enthesitis and enthesopathy are diagnosed primarily through clinical history and examination, with imaging and laboratory tests used to support the diagnosis and identify underlying causes. A combination of these modalities is often required for an accurate diagnosis.

Enthesitis is treated by measures that decrease inflammation and pain. This includes rest from activity, cold application, and anti-inflammatory medications. Physical therapy is sometimes incorporated as part of the treatment regimen.

The main treatment options for enthesitis and enthesopathy include:

• Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs such as ibuprofen, naproxen, and diclofenac are often the first-line treatment for enthesitis. They can help reduce inflammation and pain at the enthesis.
• Corticosteroid injections: Local corticosteroid injections into the affected enthesis can provide rapid relief of pain and inflammation. However, the benefits may be short-term, and repeated injections can lead to side effects such as tendon weakening.
• Disease-modifying antirheumatic drugs (DMARDs): For patients with underlying inflammatory conditions such as psoriatic arthritis or ankylosing spondylitis, DMARDs such as methotrexate, sulfasalazine, and leflunomide can help manage the underlying disease and reduce enthesitis.
• Biologic therapies: Newer biologic drugs that target specific inflammatory pathways, such as TNF-alpha inhibitors (such as adalimumab, etanercept), IL-17 inhibitors (such as secukinumab, ixekizumab), and IL-23 inhibitors (such as ustekinumab), have shown efficacy in treating enthesitis associated with conditions such as psoriatic arthritis and ankylosing spondylitis.
• Physical therapy: Stretching, strengthening exercises, and other physical therapy modalities can help improve mobility and function in patients with enthesitis. This can include techniques such as ultrasound, laser therapy, and extracorporeal shock wave therapy.
• Lifestyle modifications: For overuse or injury-related enthesopathies, rest, ice, compression, and elevation (RICE) can help manage acute symptoms. Avoiding or modifying activities that aggravate the condition is also important.
• Surgical treatment: In rare, severe, or treatment-resistant cases, surgical procedures such as tendon release or entheseal debridement may be considered, but these are generally reserved as a last resort.

Each of these treatment options can be used alone or in combination, depending on the severity of the condition, patient preferences, and response to treatment. A multidisciplinary approach often yields the best results, involving rheumatologists, physical therapists, orthopedic surgeons, and other health care professionals.

The medications used to treat enthesopathy aim to reduce pain and inflammation, as well as improve function. Here are the main categories of medications used for enthesopathy:

Nonsteroidal anti-inflammatory drugs (NSAIDs): NSAIDs are commonly used to relieve pain and reduce inflammation in patients with enthesopathy.

Examples:

• Ibuprofen (Advil, Motrin)
• Naproxen (Aleve)
• Diclofenac (Voltaren)
• Celecoxib (Celebrex)

Mechanism of action: NSAIDs work by inhibiting cyclooxygenase (COX) enzymes, which are involved in the production of prostaglandins that cause inflammation and pain.

Analgesics: These medications are used primarily for pain relief and do not have significant anti-inflammatory effects.

Examples:

• Acetaminophen (Tylenol)
• Tramadol

Mechanism of action: Analgesics work by blocking pain signals in the nervous system or by acting on certain receptors to decrease the perception of pain.

Corticosteroids: Corticosteroids are potent anti-inflammatory medications that can be used for severe inflammation.

Examples:

• Prednisone
• Methylprednisolone (Medrol)
• Dexamethasone

Mechanism of action: Corticosteroids mimic the effects of cortisol, a hormone produced by the adrenal glands, to reduce inflammation by suppressing the immune response.

Disease-modifying antirheumatic drugs (DMARDs): DMARDs are used particularly in cases where enthesopathy is related to inflammatory diseases such as ankylosing spondylitis or psoriatic arthritis.

Examples:

• Methotrexate
• Sulfasalazine
• Leflunomide

Mechanism of action: DMARDs work by modifying the immune system to slow down the progression of the disease and decrease inflammation.

Biologic DMARDs: These are a newer class of DMARDs that target specific components of the immune system.

Examples:

• Tumor necrosis factor (TNF) inhibitors: Etanercept (Enbrel), Infliximab (Remicade), Adalimumab (Humira)
• Interleukin inhibitors: Secukinumab (Cosentyx), Ustekinumab (Stelara)

Mechanism of action: Biologics work by targeting specific molecules involved in the inflammatory process, such as TNF-alpha or interleukins, to reduce inflammation and prevent joint damage.

Local injections: For localized pain and inflammation, injecting corticosteroids directly into the affected area can provide relief.

Examples:

• Triamcinolone
• Methylprednisolone

Mechanism of action: These injections deliver a high dose of corticosteroids directly to the site of inflammation, reducing local inflammation and pain.

These medications and treatments are often used in combination, depending on the severity of the condition and the underlying cause. It's essential to consult with a health care provider to determine the most appropriate treatment plan.

Platelet-rich plasma (PRP): PRP injections, which use concentrated platelets from the patient's own blood, are being investigated as a treatment to promote healing of the entheses. The growth factors in platelets may stimulate tissue repair, but more research is needed on their efficacy.

NSAIDs are the mainstay of treatment, with corticosteroid injections used for severe cases. DMARDs and biologics are used if enthesopathy is caused by inflammatory arthritis. Other adjunct therapies such as topical nitrates and PRP injections may also be tried in some cases.

The prognosis of enthesitis and enthesopathy can vary depending on the underlying cause, severity, and the patient's overall health.

Enthesitis

• Chronic condition: Enthesitis is often a chronic condition, especially when associated with systemic inflammatory diseases. The prognosis depends largely on the management of the underlying disease.
• Treatment response: With appropriate treatment, including nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs (DMARDs), and biologics (such as TNF inhibitors), many patients can achieve good symptom control and improved quality of life.
• Complications: Without effective treatment, enthesitis can lead to significant pain, stiffness, and reduced mobility. Over time, chronic inflammation can cause structural damage and contribute to joint deformities and functional impairment.
• Individual variation: The course of the disease can vary widely among individuals. Some patients experience episodic flares with periods of remission, while others may have persistent symptoms.

Enthesopathy

• Variable outcomes: The prognosis of enthesopathy varies depending on the specific condition and its cause. Non-inflammatory enthesopathies, such as tendinopathies, often have a better prognosis than inflammatory enthesopathies.
• Response to treatment: Effective management typically involves a combination of rest, physical therapy, pain management (NSAIDs, corticosteroid injections), and addressing any underlying causes (such as biomechanical issues or systemic diseases). Patients often experience significant symptom relief with appropriate treatment.
• Chronicity: Like enthesitis, enthesopathy can become a chronic issue if not adequately managed. Persistent symptoms can lead to functional limitations and impact quality of life.
• Rehabilitation: Rehabilitation and lifestyle modifications, such as weight management and ergonomic adjustments, can improve outcomes and prevent recurrence.

Early diagnosis and prompt treatment are crucial in managing both enthesitis and enthesopathy effectively. A multidisciplinary approach, involving rheumatologists, physical therapists, and other health care professionals, can optimize patient outcomes. Educating patients about their condition, treatment options, and self-management strategies is essential for long-term success. With appropriate treatment, many patients can achieve good symptom control and maintain a high quality of life.

Preventing enthesitis and enthesopathy can be challenging because they are often associated with underlying conditions such as inflammatory arthritis, overuse injuries, or mechanical stress. However, some strategies can help reduce the risk and manage symptoms:

• Manage underlying conditions: If you have a condition such as psoriatic arthritis, ankylosing spondylitis, or reactive arthritis, following your treatment plan can help manage symptoms and reduce the risk of enthesitis.
• Regular exercise: Engaging in regular, low-impact exercises such as swimming, cycling, or walking can help maintain joint and tendon health. Strengthening exercises can also support the muscles around the joints, reducing stress on the entheses.
• Proper technique: Using proper techniques during physical activities and sports can help prevent overuse injuries. Warm-up exercises before activity and stretching afterward are also beneficial.
• Footwear and orthotics: Wearing appropriate footwear that provides good support can reduce the stress on the lower extremity entheses. Orthotics or insoles may be recommended to correct biomechanical issues.
• Healthy weight: Maintaining a healthy weight reduces the load and stress on weight-bearing joints, which can help prevent enthesitis.
• Anti-inflammatory diet: A diet rich in anti-inflammatory foods, such as fruits, vegetables, omega-3 fatty acids, and whole grains, may help reduce inflammation.
• Avoid overuse: Gradually increase the intensity and duration of physical activities to avoid overuse injuries. Rest and recovery are also essential to prevent overloading the entheses.
• Medical interventions: In some cases, medical interventions such as physical therapy, corticosteroid injections, or biologic medications may be necessary to manage symptoms and prevent recurrence.

Prevention may not always be possible, as some forms of enthesitis are linked to underlying autoimmune or inflammatory conditions. In these cases, managing the root cause is key to preventing recurrent enthesitis episodes.

• Is enthesopathy arthritis? No. Enthesopathy is a condition that affects the entheses, which are the areas where tendons or ligaments attach to bones. Arthritis, on the other hand, is inflammation of the joints.
• What is the most common site of enthesitis? The most common site of enthesitis is the heel, particularly at the insertion of the Achilles tendon and the plantar fascia. Other common sites include the backbone, hips, knees, and the underside of the foot.
• Can you exercise with enthesitis? Yes, you can exercise with enthesitis, but it's important to do it carefully and under the guidance of your doctor or physical therapist. Gentle stretching, strengthening, and aerobic exercises can help reduce pain and stiffness, but avoid high-impact or strenuous workouts during flare-ups. Focus on low-impact activities such as walking, swimming, or cycling, and listen to your body to avoid overexerting yourself. Proper warm-up, stretching, and use of cold therapy after exercise can also help manage symptoms.
• What age does enthesitis occur? Enthesitis can occur at any age but is commonly seen in males between the ages of 6 and 16.