How Does PsA Affect Tendons and Ligaments?

A key feature of psoriatic arthritis (PsA) is inflammation of the connection points between bones and tendons or ligaments. Tendons are tissues that attach muscles to bones. Ligaments are tissues that attach bones to other bones.^1-3

The points where tendons and ligaments attach to bones are called entheses. Inflammation of these points is called enthesitis.^1-3

Enthesitis is more common in PsA than in other types of arthritis. In fact, enthesitis occurs in up to half of people with PsA. It is 1 of the main features of PsA.^4,5

Why do tendon and ligament problems occur with psoriatic arthritis?

Repeated stress on points where ligaments and tendons attach to bone can cause increasing damage over time. Stressors can include repetitive movements or trauma. The immune system then reacts by releasing pro-inflammatory chemicals.^2,3

In people without PsA, inflammation decreases after the stressor stops. But in people with PsA, an overactive immune system continues to cause inflammation. This leads to enthesitis. Genetic risk factors also may play a role in developing enthesitis.^2,3,6

What are possible symptoms of tendon and ligament problems?

Symptoms of enthesitis are similar to symptoms of tendonitis. Symptoms depend on where inflammation occurs.^1,2,4

A commonly affected area is the point where the Achilles tendon connects to the back of the heel. Where the plantar fascia connects to the heel is another common site of inflammation. Enthesitis also can affect other areas of the body, such as the:^1,2,4

• Elbows
• Shoulders
• Hips
• Knees

Symptoms of enthesitis include:^2,3

• Pain and stiffness when you move
• New bone formation and bone spurs
• Nail pitting

Symptoms of enthesitis often start early in the course of PsA. But they can develop at any stage of PsA. People with enthesitis often have worse health outcomes than others with PsA.²

How is enthesitis diagnosed?

Talk to your doctor if you notice pain and stiffness when you move. Your doctor will use your symptoms and medical history to diagnose any tendon and ligament problems. Diagnosis is an important part of assessing overall PsA severity.^1,2

Enthesitis often looks similar to tendonitis and fibromyalgia. Your doctor may use medical imaging tests to make an accurate diagnosis. These tests include ultrasound and magnetic resonance imaging (MRI). They may use a scoring system to diagnose enthesitis with these tests.^1,2

How is enthesitis treated?

Treating enthesitis can improve long-term PsA outcomes. Treatment depends on symptom severity and location. Initial treatment generally involves taking NSAIDs to reduce pain and inflammation. A corticosteroid injection may help if symptoms affect only 1 location of the body.^2,5,7

If symptoms persist or affect several body parts, your doctor may prescribe biologic drugs, or biologics. The most effective biologics for PsA seem to be tumor necrosis factor (TNF) blockers.^2,7

Doctors are exploring how well other biologics may treat enthesitis as well. Many conventional disease-modifying antirheumatic drugs (DMARDs) do not work to treat enthesitis.^2,7