yoga book / pathologie / schnellender finger

Definition

The rapid finger is a tendon gliding disorder that leads to an inhibition of extension of a finger, usually at the level of the A1 ring ligament in the metacarpophalangeal joint area, occasionally also in the PIP. It is usually caused by degenerative changes in the finger flexor tendons. In most cases, tendon sheath inflammation (tendovaginitis stenosans) occurs as a result of overuse, but this alone does not necessarily manifest itself as a trigger finger until the thickening has become sufficiently large.

Clinically, the attempt to stretch the affected finger leads to a noticeable resistance that prevents further stretching of the finger in the distal joints. If more and more and finally sufficient tensile force is built up in the associated finger extensor, the resistance of the thickened tendon in the ring ligament is overcome with a jerk, which leads to rapid movement of the finger in the distal joints. There is therefore no fine control of the movement corresponding to human fine motor skills, but first none and then a jerky movement over larger arc dimensions. Naturally, the fine motor skills for this finger are permanently impaired.

The extension inhibition usually affects the finger metacarpophalangeal joint, but can also affect the proximal interphalangeal joint. The third finger (middle finger) is most commonly affected, followed by the fourth (ring finger). The phenomenon often occurs as an early symptom of rheumatoid arthritis. Traumatic genesis is rather rare, as are tumours as a cause. The thickenings usually consist of scarred fibre bundles that have developed as a result of overuse or microtrauma. The mechanical stresses placed on the tendon in everyday life can lead to varying degrees of paradeninous oedema, which explains the inconsistent nature of the phenomenon. The rapid movement can be painless at first, but painful in later phases. The phenomenon is most common in the morning, as the fingers are usually more or less bent during the night. Women are more frequently affected than men, and sometimes there is a co-morbidity with another bottleneck syndrome such as carpal tunnel syndrome or bouchard arthrosis or Heberden arthrosis. For both arthroses, a reciprocal causality has not yet been found; they presumably arise from a common cause or predisposition. Rapid finger also occurs together with Dupuytren’s disease. A thickening can be palpated on the palmar side of the metacarpal bone or the proximal phalange.

The prevalence in Germany is about 3%, the peak age between 50 and 60. W:M 6:1. This disorder occurs as an occupational disease in pianists and possibly also other instrumentalists, athletes, craftsmen, people who type a lot

Cause

1. Overuse
2. rare: Trauma
3. rare: Tumour

Predisposing

1. Activities with frequent, especially heavy use of the finger flexors, such as gardening, golf, tennis, powerful work with pliers, weight training, climbing
2. RA
3. Metabolic disorders such as diabetes mellitus or gout
4. Poor posture, e.g. sleeping with fingers bent wide
5. Genetic predisposition

Diagnose

1. Clinical: visually in the stretching test
2. palpatoric: possibly palmar thickening of the head of the metacarpal bone or proximal phalanges
3. Pressure tenderness over the tendovaginitis
4. Sono

Symptome

1. Progressive inhibition of stretching that occurs mainly after a night’s sleep, which is overcome when greater force is applied and manifests itself in a jerky movement.

Complications

1. Stiffening of the finger joints that existed before the operation can persist
2. untreated: Inability to actively stretch (by one’s own power), then the resistance must be overcome passively.

Therapie

1. In the initial phase, treatment of tendovaginitis can be tried
2. Surgical: widening of the annular ligament, usually with local anaesthesia (wide awake procedure: anaesthesia plus adrenaline for vasoconstriction), rarely with plexus anaesthesia

DD

1. Morbus Dupuytren