These are uncommon proximal lesions for which the objective will be to allow partial (loose) finger grip and lateral thumb-index grip (key pinch) through active tenodesis by transferring the brachioradialis to the wrist extensors, combined with a tenodesis (attachment of specific tendons) of the thumb.
Wrist extensor muscle
These are quite common lesions requiring three distinct surgical procedures:
- First stage: procedure in which elbow extension is locked by transferring the biceps to the triceps
- Second stage in which finger opening is restored by finger extensor tenodesis (tendon attachment) and thumb tenodesis
- Third stage in which finger closing or finger flexing is restored by transferring the brachioradialis to the deep finger flexors, which can be associated with a Zancolli capsulorrhaphy
Pronator teres muscle
The therapeutic scheme is the same but the closing stage will include wrist flexion from the pronator teres muscle in addition to finger flexion restoration.
Triceps and flexors carpi radialis muscles
The opening stage will be active with a transfer of the brachioradialis to the finger extensors and long thumb extensor combined with a tenodesis of the thumb's long flexor.
The closing stage will include a transfer of the long wrist extensor to the deep flexors, which can be combined with a Zancolli capsulorrhaphy.
Finger extensor muscle
An additional opening synchronization stage is often necessary however.
The closing stage corresponds to an active finger flexion transfer by a wrist extensor and an active thumb flexion transfer by the brachioradialis, which can be combined with a Zancolli capsulorrhaphy.
Finger flexor muscle
Surgery will aim at restoring the intrinsic function as much as possible using Zancolli’s “lasso”procedure with an opposition transfer for the thumb.