What is Tenosynovitis
Tenosynovitis is inflammation of the synovial sheath that surrounds a tendon, characterized by pain, swelling, and tenderness along the affected tendon. 1, 2
Anatomical Definition
- Tenosynovitis specifically involves the synovial membrane that encases tendons, distinguishing it from tendinitis which affects the tendon substance itself 1, 2
- The condition can affect any tendon in the body but most commonly occurs in the extremities, particularly the hand, wrist, and foot, due to their intricate tendon arrangements that permit fine motor actions 2, 3
Clinical Presentation
- The symptomatic triad includes: pain at palpation of the affected tendon, pain induced by passive stretching of the tendon, and pain with resisted muscular contraction 3
- Patients typically present with localized swelling, stiffness, and tenderness along the tendon sheath 1, 2
- In inflammatory arthritis contexts (such as rheumatoid arthritis or psoriatic arthritis), tenosynovitis manifests as joint stiffness and swelling, often with involvement of surrounding ligaments and tendons 4
Types and Locations
Common forms include:
- De Quervain tenosynovitis affecting the first dorsal compartment of the wrist 5, 1
- Trigger finger involving the flexor digitorum tendons 1
- Stenosing tenosynovitis of the extensor carpi ulnaris, extensor carpi radialis, or extensor communis tendons 1
- Posterior tibial tendon tenosynovitis 6
- Flexor hallucis and peroneal tendon tenosynovitis 1
Etiology
Multiple factors contribute to tenosynovitis development:
- Mechanical factors including overuse, repetitive movements, and local anatomical constraints 1, 3
- Inflammatory conditions such as rheumatoid arthritis, psoriatic arthritis, and seronegative spondyloarthropathies 4, 6
- Infectious causes, including secondary syphilis (though rare) 7
- Hormonal factors 1
Clinical Significance in Inflammatory Arthritis
- Tenosynovitis serves as an important prognostic marker: baseline tenosynovitis on ultrasound predicts erosive progression at 1 year (OR 7.18) and 3 years (OR 3.4) in rheumatoid arthritis 4, 8
- MRI-detected tenosynovitis is the strongest risk factor for arthritis development in at-risk individuals (HR 8.39,95% CI 3.38-20.81) 4
- In psoriatic arthritis, tenosynovitis commonly presents as "dactylitis" or "sausage digit," combining enthesitis and synovitis involving an entire digit 4
Diagnostic Approach
- Clinical diagnosis relies on the symptomatic triad described above, combined with localized findings on examination 3
- Ultrasound is the first-line imaging modality, showing thickened, hypoechoic tenosynovial sheath and, in stenosing forms, a thickened retinaculum or pulley constricting the osseofibrous tunnel 8, 1
- MRI is reserved for cases where ultrasound is inconclusive or when deeper structures require evaluation 8