Objective/Hypothesis: In this study, our aim is to present our results with the “switch technique” in the dynamic restoration of forearm pronation and wrist radial deviation in patients with “the beggar’s hand” caused by obstetric brachial plexus palsy. In the “switch technique,” the tendons of two functional muscles are sectioned at two different levels, and the proximal muscular units are transposed to the presectioned distal tendon ends in a cross fashion. This technique enables the dynamic restoration of the paralytic and complex deformity. Materials and Methods: Eleven obstetric palsy patients (6 male, 5 female) with ages ranging between 5 and 10 years (mean age of 7.6 years) were operated for the correction of supination deformity and ulnar deviation of the wrist. Soft tissue releases were performed at the forearm and the wrist. Extensor carpi ulnaris (ECU), brachioradialis (BR), abductor pollicis longus (APL), and the flexor carpi ulnaris (FCU) muscles were prepared. The ECU tendon was sectioned and disinserted from its insertion whereas the BR tendon was sectioned just distal to the myotendinous junction. The distal end of the BR tendon was rotated around the radius from the dorsal to the volar, and then, it was advanced proximally along the interosseous membrane after being passed through a pulley that was prepared from the distal end of the FCU tendon. The ECU tendon was advanced from the dorsal to the volar, and it was sutured to the BR tendon as a pronator. The APL tendon was sectioned from a proximal level, and the distal end of this tendon was sutured to the proximal end of the BR tendon as a wrist radial deviator. The mean follow-up time was 14 months (4-31 months). Forearm pronosupination, wrist flexion-extension, and ulnar-radial deviation were assessed by goniometric measurements. Results: Mean active forearm pronation was −42.5° preoperatively. After the surgery, 38.75° degrees of active forearm pronation was achieved. Preoperative and postoperative mean active radial deviation values were −7.5° and 10.75°, respectively. All patients reported that they became more capable in activities such as turning pages and holding a mug. Conclusions: The tendons that are used in the “switch technique” are not paralytic, and they are functional. In fact, this is a major difference with classic tendon transfers. With this technique, the original muscle bellies and the routes of the tendons are switched. They are used for impaired targets, and they are reorganized for the restoration of insufficient functions. Correction of the deformity improves the appearance of the limb and the self-confidence of the child and allows the patients to integrate well into the society. These results suggest that selected cases may benefit from restoration of “the beggar’s hand” deformity with the “switch technique” that may produce a critical improvement in functional capabilities.
