Diagnosis of Wrist Tendinitis
Wrist tendinitis is diagnosed primarily through clinical examination with focused history and physical findings, followed by ultrasound (US) or MRI without IV contrast for confirmation when imaging is needed.
Clinical Diagnosis
The diagnosis begins with identifying specific clinical patterns:
- Pain location and provocative maneuvers: Localized tenderness over specific tendon compartments with pain on resisted movement of the affected tendon 1
- Common presentations include de Quervain tenosynovitis (first dorsal compartment), intersection syndrome, extensor carpi ulnaris (ECU) tendinitis, and flexor carpi radialis tendinitis 1
- ECU synergy test: For ECU tendinitis specifically, this test differentiates extra-articular tendon pathology from intra-articular ulnar-sided wrist problems 2
Imaging Algorithm
When clinical examination suggests tendon pathology, the diagnostic imaging pathway is clearly defined by the 2024 ACR Appropriateness Criteria 3:
Initial Imaging
- Plain radiographs first to exclude bony pathology and arthritis 3
Confirmatory Imaging (when radiographs are normal or show nonspecific arthritis)
Ultrasound is the preferred initial confirmatory test 3:
- Tendon injuries are ideally suited for US due to superficial location and ability to perform dynamic assessment
- US can diagnose: tendinopathy, tendon tears, intersection syndrome, tenosynovitis, stenosing tenosynovitis, pulley injuries, sagittal band pathology, and palmar fibromatosis 3
- Key US findings: Increased tendon thickness and peritendinous edema are the most reliable imaging features 4
- US allows real-time dynamic examination with active finger flexion/extension 5
MRI without IV contrast is the alternative confirmatory test 3:
- Excellent soft tissue contrast resolution makes it ideal for assessing tendon abnormalities
- Can diagnose the same spectrum of pathology as US
- MRI with IV contrast improves detection of tenosynovitis specifically 3
- Typical MRI findings: Increased tendon thickness, peritendinous edema, increased intratendinous signal, and surrounding subcutaneous edema 4, 6
Important Caveats
Anatomical pitfalls to avoid misdiagnosis:
- Multiple bundles of the abductor pollicis longus tendon are normal variants, not tendon splitting 7
- Centrally increased signal in the extensor carpi ulnaris tendon from fibrovascular tissue is a normal finding 7
- For proximal intersection syndrome, the MRI field must extend 4-8 cm proximal to Lister's tubercle 7
Modalities to avoid: CT (with or without contrast), bone scan, CT arthrography, and MR arthrography have no role in diagnosing wrist tendinitis 3
Diagnostic Confirmation
When US or clinical findings suggest tendinitis, diagnostic injection with local anesthetic or corticosteroid into the tendon sheath can provide both therapeutic benefit and diagnostic confirmation—greater than 90% pain relief confirms the diagnosis 2, 1.