Procedure 21 Steindler Flexorplasty
Indications
Late presentation of upper trunk brachial plexus palsy (C5-C6; C5-C6-C7) without recovery of elbow flexion.
Examination/Imaging
Clinical Examination
The patients should have adequate strength in the flexor pronator mass, especially the wrist flexors [flexor carpi radialis (FCR) and flexor carpi ulnaris (FCU)]. This can be assessed by asking the patient to flex the wrist against resistance.
The patient should have good wrist extension to counteract the possible development of a wrist flexion contracture.
The patients should have adequate passive flexion of the elbow. If passive flexion of the elbow is limited owing to a tight triceps, then triceps lengthening may be necessary to increase passive range of motion.
Surgical Anatomy
The common flexor-pronator muscles originate from the medial epicondyle. The following muscles are elevated during this procedure: pronator teres, FCR, palmaris longus, FCU, and flexor digitorum superficialis (Fig. 21-1). The flexor digitorum profundus is left in situ (see Fig. 21-1).
The ulnar nerve must be protected during elevation of the flexor-pronator mass. It may be transposed anteriorly in the submuscular plane.
The medial (ulnar) collateral ligament of the elbow should be protected during elevation of the flexor-pronator mass. It originates at the posterior distal aspect of the medial epicondyle and inserts into the base of the coronoid process of ulna. It is composed of three bands: anterior, posterior, and transverse (Fig. 21-2).
Exposures
A 10-cm longitudinal curvilinear incision centered over the medial epicondyle is made (Fig. 21-3).
A skin flap is elevated while protecting the medial antebrachial cutaneous nerve. After elevation of the skin flap, one will see the flexor-pronator mass attaching to the medial epicondyle (Fig. 21-4).