Understanding Enthesopathy
Enthesopathy is a pathological condition affecting the entheses, which are the sites where tendons, ligaments, joint capsules, or fascia attach to bone. 1
Definition and Classification
Enthesopathy can be classified into several types based on etiology:
- Inflammatory - Associated with seronegative spondyloarthropathies (SpA) including psoriatic arthritis, ankylosing spondylitis, reactive arthritis, and enteropathic arthritis 1, 2
- Degenerative - Often related to mechanical stress and overuse
- Metabolic - Associated with conditions like gout
- Endocrine - Related to hormonal disorders
- Traumatic - Resulting from injury 1, 3
Common Sites of Involvement
Enthesopathy commonly affects:
- Pelvis
- Femoral trochanter
- Humeral tuberosity
- Patella
- Olecranon
- Calcaneus
- Portions of the vertebral column 3
Clinical Presentation
Patients with enthesopathy typically present with:
- Pain at attachment sites
- Tenderness on palpation
- Stiffness
- Swelling
- Limited range of motion
- Functional impairment 1
Diagnostic Imaging
Radiographic Features
Specific radiographic features may include:
- Bone erosion
- Hyperostosis
- Fragmentation
- Crystal deposition 3
Advanced Imaging
Ultrasound is the first-line imaging modality with 2.48-4.69 times better detection rate than clinical examination. It can identify:
- Synovial thickening
- Fluid in tendon sheath
- Increased vascularity 1
MRI is superior for detecting early signs of enthesitis and can evaluate both soft-tissue changes and intraosseous abnormalities 1
Power Doppler US is useful for differentiating mechanical/degenerative and inflammatory enthesopathy 4
Clinical Significance
Enthesitis is a hallmark feature of spondyloarthropathies and is critical for diagnosis. In inflammatory arthritis, bone proliferation in the form of periostitis and enthesitis is characteristic of spondyloarthropathies and may occur at any cortical bone, including both tendon and ligament attachments 5.
Enthesopathy can often be asymptomatic in both axial and peripheral skeleton, making systematic ultrasound evaluation useful in the diagnostic process 4.
Treatment Approaches
Management of enthesopathy includes:
Non-pharmacological approaches:
- Relative rest
- Activity modification
- Splinting
- Physical therapy with eccentric strengthening exercises
- Ergonomic education
- Cryotherapy 1
Pharmacological treatments:
- NSAIDs as first-line treatment for short-term pain relief
- Corticosteroid injections for localized symptoms
- Disease-modifying antirheumatic drugs (DMARDs) for inflammatory enthesopathy 1
Prognosis and Complications
- Early detection and treatment are crucial to prevent long-term complications
- Untreated enthesopathy can lead to considerable morbidity 2
- Enthesitis predicts erosive progression in inflammatory arthropathies
- Regular monitoring with ultrasound helps assess treatment response 1
Clinical Pitfalls to Avoid
- Failing to distinguish between inflammatory and mechanical enthesopathy, which require different treatment approaches
- Overlooking enthesopathy as a manifestation of systemic disease
- Misdiagnosing enthesopathy as simple bursitis, which closely mimics it 2
- Neglecting to consider medication-induced enthesopathy, such as that associated with retinoid therapy 6