Procedure 27 Flexor Carpi Ulnaris–to–Extensor Carpi Radialis Brevis Transfer
Examination/Imaging
Clinical Examination
Cerebral palsy: The flexion deformity in cerebral palsy can be due to spasticity of the wrist flexors, weak wrist extensors, and/or a volar wrist capsular contracture. It is important to differentiate among these causes. An attempt at overcoming muscle spasticity should be done by applying gentle sustained resistance to the spastic force. If the wrist can be extended passively, it rules out capsular contracture. If the wrist cannot be extended passively, but the wrist flexors do not feel spastic, it suggests a wrist capsular contracture. If the spasticity cannot be overcome, a median and ulnar nerve block at the elbow can temporarily eliminate the flexor spasticity and allow an assessment of active and passive wrist extension. An FCU-to–extensor carpi radialis brevis (ECRB) transfer is indicated in patients who have a spastic FCU and good passive wrist extension (no capsular contracture) but lack active wrist extension. Before considering an FCU-to-ECRB transfer, one must ensure that the patient has the following:
Surgical Anatomy
The purely tendinous portion of the FCU is quite short as the muscle extends distally along the tendon. In addition, the muscle is attached along the ulna over a long distance. The muscle must be detached quite proximally to have adequate excursion of the transferred FCU (Fig. 27-2).
The ulnar artery and nerve are very closely related to the undersurface of the FCU and must be protected during mobilization of the FCU (Fig. 27-3).
