[Extensor tenodesis to the retinaculum extensorum: anatomic and biomechanical study]

Wrist fusion in peripheral paralysis

In cases of paralysis of the upper limb, wrist fusion is useful in selected indications, especially when there are little to no tendon transfers available to restore finger function and wrist extension. Wrist fusion is particularly useful in the sequelae of brachial plexus lesions and in total paralysis of the radial nerve with hand drop and preserved wrist flexors. Numerous fusion techniques have been proposed. In cases of sequelae of brachial plexus lesions, locking of pronation-supination is associated with the wrist fusion. The use of anatomical plates has dropped the non-union and complication rates.

Tendon transfers for C8-T1 palsy of the brachial plexus in adults

Brachial plexus palsy after C8-T1 nerve root injury is rare, but causes a loss of finger flexion and extension, which greatly limits the patient's grip function. It can benefit from nerve transfers if the diagnosis is made early. Otherwise, tendon transfers may be proposed. Transfers of the extensor carpi radialis longus and brachioradialis to the flexor digitorum profundus and the flexor pollicis longus, respectively, restores finger flexion and thumb flexion. Tenodesis of the extensor digitorum communis allows passive extension of the fingers during active wrist flexion. Translocation of the flexor pollicis longus and the creation of a "lasso equivalent" on the flexor digitorum superficialis provides some recovery of the intrinsic function of the fingers and thumb. Finally, a nerve transfer of the lateral cutaneous nerve of forearm on the superficial branch of the ulnar nerve can improve sensitivity on the ulnar edge of the hand to limit the risk of cutaneous lesions, which frequently occur in this type of paralysis.

Dynamic tenodesis of the finger extensors to improve hand function after brachial plexus injury

The term "plexic hand" refers to hand and wrist involvement in traumatic brachial plexus injuries and to remaining deficits after nerve surgery has been performed. From January 2000 to March 2008, reconstructive surgery (dynamic tenodesis) was performed on seven patients with C5, 6, 7, and 8 nerve root lesions of the brachial plexus to restore wrist and finger extension. This procedure has been used in seven patients (one female). Two patients with a lesion of the brachial plexus sustained a fracture of the affected limb. Preliminary nerve repair operations were required in four cases. One hundred percent (seven) of the patients had improved function following dynamic tenodesis. The extension angle of the wrist joint on grip was 19° on average. The flexion angle of the wrist joint needed to produce MP joint extension was 24.3° on average. A new dynamic extensor tenodesis technique is proposed. The extensor digitorum communis tendons are looped through dorsal carpal retinaculum ligament and sutured to themselves. Our results demonstrate that the extensor dynamic tenodesis procedure is an effective and simple means of restoring grip function for patients with C5, 6, 7, and 8 nerve root lesions.

[Tenodesis in hand surgery]

Joining tendon's inextensibility with joint's mobility, a tenodesis fixes on the bones the two ends of a tendon on both sides of one or several joints. A "simple" tenodesis overrides only one joint, whereas a "dynamic" tenodesis crosses two or more joints. A "crossed" dynamic tenodesis crosses the line which joins rotation axes. A "direct" dynamic tenodesis is located on the same side of this line. The "tenodesis effect" is normally produced by the movements of the joint on the neighbouring tendons. Anatomical examples are given by the oblique retinacular ligaments (crossed dynamic tenodesis), and by the tenodesis effects linked to the flexion-extension of the wrist on the extrinsic tendons of the fingers (direct tenodesis effect), or to the flexion-extension of the PIP joints on the intrinsic tendons of the fingers (crossed tenodesis effect). Main tenodesis techniques are used for palliative surgery in paralysis of EDC, intrinsic muscles of the fingers, or extrinsic muscles of the thumb (EPL, FPL, APL and EPB).