|
|
||||||||
Radiologic-Pathologic Conference |
1 Department of Radiology, Wake Forest University School of Medicine, Medical
Center Blvd., Winston-Salem, NC 27157-1088.
2 Department of Radiology, Keller Army Community Hospital, West Point, NY
10996-1197.
3 Department of Radiology, Madigan Army Medical Center, Bldg. 9040, Fitzsimmons
Dr., Tacoma, WA 98431.
4 Department of Surgical Pathology, Madigan Army Medical Center, Tacoma, WA
98431.
5 Orthopedic Service, Department of Surgery, Madigan Army Medical Center,
Tacoma, WA 98431.
Received September 28, 2001;
accepted after revision December 6, 2001.
From the radiologicpathologic correlation conferences of Madigan
Army Medical Center.
Introduction
|
|
|---|
|
|
|
|
Guyon's canal is also known as the "pisohamate tunnel" or the "distal ulnar tunnel." The roof of the tunnel consists of the palmar carpal ligament, the palmaris brevis, and the hypothenar fat and fibrous tissue. The tendons of the flexor digitorum profundus, the transverse carpal ligament, the pisohamate and pisometacarpal ligaments, and the opponens digiti minimi form the floor of the tunnel. The medial wall includes the flexor carpi ulnaris, the pisiform, and the abductor digiti minimi manus. The tendons of the extrinsic flexors, the transverse carpal ligament, and the hook of the hamate constitute the lateral wall.
Guyon's canal consists of three zones. Zone 1 extends from the proximal edge of the palmar carpal ligament to the bifurcation of the ulnar nerve. Zones 2 and 3 are adjacent to each other, extending from the bifurcation of the ulnar nerve just distal to the fibrous arch of the hypothenar muscles. These zones contain the deep motor branch and the superficial sensory branch of the ulnar nerve, respectively. Clinical symptoms correlate with the zone in which ulnar nerve compression occurs: combined motor and sensory deficits occur in zone 1 lesions; pure motor deficits, in zone 2 lesions; and isolated sensory deficits, in zone 3 lesions.
Compressive neuropathies of the ulnar nerve occur most commonly at the elbow and less commonly at the wrist [1]. The most common causes of ulnar nerve compression at the wrist are ganglia, fractures, anomalous muscles, thrombosis, bursitis, and a thickened pisohamate ligament [2]. Repeated blunt trauma to the hypothenar area may cause ulnar neuritis, which is commonly seen in chiropractors, bikers, and construction workers [1].
Physical examination may reveal the presence of Tinel's sign, swelling, discoloration, or a palpable mass. When a vascular lesion is suspected, listening for a bruit and performing the Allen test and Doppler sonography are helpful. Electrodiagnostic studies are useful but are not always diagnostic. MR imaging is the most helpful radiologic examination.
Lipoma of the Guyon's canal is a rare cause of ulnar neuropathy [3, 4]. Treatment involves complete excision of the lipoma.
|
|
|---|
This article has been cited by other articles:
![]() |
G. Andreisek, D. W. Crook, D. Burg, B. Marincek, and D. Weishaupt Peripheral Neuropathies of the Median, Radial, and Ulnar Nerves: MR Imaging Features RadioGraphics, September 1, 2006; 26(5): 1267 - 1287. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. Blum, J.-P. Zabel, R. Kohlmann, T. Batch, K. Barbara, X. Zhu, G. Dautel, and F. Dap Pathologic Conditions of the Hypothenar Eminence: Evaluation with Multidetector CT and MR Imaging. RadioGraphics, July 1, 2006; 26(4): 1021 - 1044. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. L. CRIBB, W. P. COOL, D. J. FORD, and D. C. MANGHAM Giant Lipomatous Tumours of the Hand and Forearm J Hand Surg Eur Vol., October 1, 2005; 30(5): 509 - 512. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |