De Quervain's disease

Anatomy of the wrist joint and tendons

The wrist joint is frequently subject to injuries due to excessive loading (overuse injuries), which can lead to significant impairment of hand function. Tendons in this region are anatomically divided into two main groups: flexors (flexor tendons) and extensors (extensor tendons).

The flexor tendons are predominantly grouped within the carpal tunnel (carpal tunnel). Exceptions to this rule are the tendons of the flexor carpi ulnaris (flexor carpi ulnaris) and flexor carpi radialis (flexor carpi radialis), which pass outside this canal.

The extensor tendons are located dorsally. The extensor retinaculum (retinaculum extensorum) forms six isolated osteofibrous compartments for them. The numbering of these groups at the wrist level always proceeds in a radial-to-ulnar direction (radial-to-ulnar direction).

Six extensor compartments

To reduce tendon friction against dense structures, all six compartments are lined with specialized synovial sheaths. The distribution of tendons by compartments is as follows:

1. Abductor pollicis longus and extensor pollicis brevis (APL + EPB).
2. Extensor carpi radialis longus and brevis (ECRL + ECRB).
3. Extensor pollicis longus (EPL).
4. Extensor digitorum and extensor indicis (ED + EI).
5. Extensor digiti minimi (EDM).
6. Extensor carpi ulnaris (ECU).

Pathogenesis of de Quervain's disease

de Quervain's disease (de Quervain's disease) is a stenosing tenosynovitis directly associated with tendinopathy of the first extensor compartment. The disorder selectively affects the tendons of the abductor pollicis longus (abductor pollicis longus) and extensor pollicis brevis (extensor pollicis brevis).

The pathology manifests upon inflammation of the synovial sheaths of the first compartment. This process results in marked tissue thickening, which disrupts normal tendon biomechanics and leads to joint dysfunction.

Ultrasound diagnostics

To visualize de Quervain's disease, it is optimal to use longitudinal grey-scale ultrasound (grey-scale ultrasound) of the first extensor compartment tendons.

The ultrasound image clearly demonstrates the following diagnostic signs:

• Thickening of the tendon structure itself.
• Echogenic thickening of the tendon sheath, which directly corresponds to the pattern of stenosing tenosynovitis.
• Using power Doppler mode reveals accompanying neovascularization of the affected tendon.

Differential diagnosis: ECU tendinopathy

By comparison, sixth extensor compartment tendinopathy affects the extensor carpi ulnaris (ECU) tendon. It most commonly occurs where the tendon passes over the ulnar styloid.

This is a typical localization of tenosynovitis developing in the setting of various inflammatory arthropathies. Prolonged inflammation of this type can eventually lead to erosion of the ulnar styloid process.

Class and exam questions

What else to study on this topic

• Stener lesion: rupture of the ulnar collateral ligament of the thumb with stump retraction.
• Diagnostic imaging of scapholunate ligament tears and assessment of diastasis on fat-suppressed MRI.
• Digital subtraction arthrography in wrist ligament injuries and contrast leakage.
• Osteochondritis dissecans of the humeral capitellum and search for loose intra-articular bodies.
• Insertion tendinopathies of the elbow joint and ultrasound-guided injection therapy.

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.