De Quervain Tenosynovitis: Affected Tendons
De Quervain tenosynovitis affects the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons within the first dorsal compartment of the wrist. 1, 2, 3, 4
Primary Tendons Involved
The condition specifically involves stenosing tenosynovitis of two tendons that pass through the first dorsal compartment:
- Abductor pollicis longus (APL): This tendon abducts the thumb and is consistently involved 3, 5, 4
- Extensor pollicis brevis (EPB): This tendon extends the thumb at the metacarpophalangeal joint 3, 5, 4
Both tendons become inflamed within their shared fibro-osseous canal on the radial (thumb) side of the wrist, causing the characteristic pain with resisted gliding 4.
Anatomical Variations to Consider
Anatomical variations within the first dorsal compartment are common and clinically significant:
- Subcompartmentalization occurs in approximately 79% of patients with de Quervain tenosynovitis, where a septum divides the first dorsal compartment into separate channels for the APL and EPB 6
- Accessory APL tendons are frequently present, with some patients having multiple APL slips 7, 5, 6
- Ultrasound can identify these variations, showing thickened, hypoechoic tenosynovial sheath surrounding the tendons and detecting septations that affect surgical planning 8, 2, 5
Clinical Pitfalls
Failure to recognize anatomical variations leads to treatment failure:
- Subcompartments must be identified during surgical release, as incomplete release of all compartments results in persistent symptoms 7, 6
- Accessory tendons can be at risk for subluxation over bony prominences if not properly addressed 7
- The American College of Radiology recommends ultrasound for confirming diagnosis and identifying these variants when surgical planning is needed 2