Ulnar nerve compression following flexor digitorum superficialis tendon transfers around the ulnar border of the forearm to restore digital extension: case report

Tendon transfer surgery for radial nerve palsy

Palliative tendon transfer is an integral part of radial nerve palsy treatment. It can be considered in the first weeks when the possibility of nerve repair by direct suture or nerve grafting is not feasible or reasonable. Mostly, it is discussed secondarily when it is too late for nerve surgery and motor recovery cannot be expected, or after failure or incomplete recovery after nerve repair. The goal of tendon transfers is to restore wrist, finger and thumb extension. For wrist extension, the use of pronator teres is well accepted. The best tendon transfer for finger extension is debated. This can be restored doing a flexor carpi ulnaris (FCU), flexor carpi radialis or flexor digitorum superficialis (FDS) to extensor digitorum communis transfer. Regarding thumb extension and abduction, a palmaris longus (PL) or one FDS tendon to the rerouted extensor pollicis longus (EPL) transfer can be performed. If a transfer is done on the EPL without rerouting it, abduction can be restored by doing a tendon transfer to the abductor pollicis longus (APL) or an APL tenodesis. The different tendon transfer options are selected based on the surgeon's preference, and most importantly, discussed with the patients to define the objectives together. The transfer is chosen based on the clinical examination (high or low radial nerve palsy, tendon available for transfer like PL, wrist mobility) and based on the patient's needs and expectations (activities requiring the FCU, finger independence, independence of thumb extension or abduction). If the surgical rules and the postoperative instructions for rehabilitation are followed, tendon transfers for radial nerve palsy regularly produce very satisfactory results.

Ulnar tunnel syndrome

Ulnar neuropathy at or distal to the wrist, the so-called ulnar tunnel syndrome, is an uncommon but well-described condition. However, diagnosis of ulnar tunnel syndrome can be difficult. Paresthesias may be nonspecific or related to coexisting pathologies, such as carpal tunnel syndrome, cubital tunnel syndrome, thoracic outlet syndrome, C8-T1 radiculopathy, or peripheral neuropathy, which makes accurate diagnosis challenging. The advances in electrodiagnosis, ultrasonography, computed tomography, and magnetic resonance imaging have improved the diagnostic accuracy. This article offers an updated view of ulnar tunnel syndrome as well as its etiologies, diagnoses, and treatments.

Ulnar tunnel syndrome

As our understanding of the anatomy of the ulnar tunnel has increased, so too has our ability to clinically predict the specific sites of compression in ulnar tunnel syndrome. Anatomic studies have described in detail the course of the ulnar nerve as it passes through the ulnar tunnel and have helped correlate symptoms with anatomic location. Although the most common cause of compression is from a ganglion, other space-occupying lesions, such as tumors, anomalous muscles, or a thrombosed ulnar artery, are important to consider in the initial evaluation of the patient. While conservative management can sometimes be successful, the mainstay of treatment of this condition remains meticulous surgical exploration and decompression.

Unusual complication of an opposition tendon transfer at the wrist: ulnar nerve compression syndrome

Restoration of thumb opposition by tendon transfer may be necessary in cases of severe thenar atrophy caused by long-standing carpal tunnel syndrome. Routing the extensor indicis proprius transfer subcutaneously around the ulna to reanimate thumb opposition is an accepted procedure and is considered safe. Ulnar nerve compression leading to palsy is possible, however, as shown in the patient presented. Neurolysis failed to improve the palsy. Rerouting of the transfer deep to the ulnar nerve was necessary to treat the iatrogenic condition. Possible nerve compression should be kept in mind when planning a tendon transfer around the ulnar side of the forearm or carpus and when following up with the patient. Early intervention is necessary to prevent permanent sequelae.

Bilateral carpal tunnel syndrome after abductor digiti minimi opposition transfer: a case report

We present a case of bilateral, delayed-onset, median nerve compression at the wrist after abductor digiti minimi opposition transfer for thumb hypoplasia. The symptoms resolved on each side after transverse carpal ligament release without disruption of the opposition transfers.

Tendon transfers for failed nerve reconstruction

There are few reconstructive procedures in the upper extremity that are as helpful to patients as a tendon transfer. Successful tendon transfer requires the marriage of anatomic knowledge, surgical judgment, and rehabilitative expertise. Frequently, the improvement in function can be dramatic. By the same token, an unsuccessful tendon transfer wastes a normal muscle-tendon unit in the hand and leaves the patient withless function than what was present preoperatively.