Pathologic Conditions of the Hypothenar Eminence: Evaluation with Multidetector CT and MR Imaging

Abstract

Pain, weakness, and sensory loss occur frequently in the hypothenar eminence. However, clinical examination is difficult and nonspecific, and the prescribed imaging technique may be inadequate, or images may be misinterpreted. Different imaging modalities have various degrees of usefulness for the diagnosis of painful pathologic conditions of the hypothenar eminence. Radiography, multidetector computed tomography (CT), multidetector CT arthrography, and magnetic resonance (MR) imaging of the wrist are useful for surveying the anatomy of the hypothenar eminence, the Guyon canal, and the ulnar nerve and artery and for determining the cause of pain or other symptoms. A fracture of the pisiform bone or the hook of the hamate bone, osteoarthritis or osteochondromatosis of the pisotriquetral joint, Guyon canal syndrome, hypothenar hammer syndrome, tendinopathy of the flexor carpi ulnaris, an anomalous muscle, a ganglion cyst, or a tumor may be responsible for ulnar neuropathy. Specific radiographic views, such as the semisupinated oblique view and the lateral view with the hand radially deviated and the thumb abducted, often provide a sufficient basis for the diagnosis of acute fracture of the hook of the hamate or the pisiform bone. Multidetector CT angiography is an efficient method for diagnosing hypothenar hammer syndrome, and multidetector CT arthrography is well suited for evaluation of the pisotriquetral joint. MR imaging is the modality of choice for depiction of the ulnar nerve.

The Hand and Wrist: Acquired Disorders

“…Ulnar neuropathy often affects athletes who perform repetitive wrist motion: impaction, as in racquet sports, or pressure, as in biking (handlebar palsy) [ 62 ]. Continuous exposure of this area to vibratory forces (e.g., from frequent use of a drill) increases risk of ulnar neuropathy [ 62 ]. Guyon canal, also known as the pisohamate tunnel, is a fi bro-osseous canal along the ulnar and volar aspects of the wrist.…”

“…Hypothenar hammer syndrome (aneurysm formation and possible thrombosis) has been described but is generally uncommon in the pediatric population [ 62 ]. These injuries generally occur in athletes, particularly those who play racquet sports, along with baseball catchers, martial artists, and breakdancers [ 62 ]. CT angiography best evaluates this condition [ 62 ].…”

Hypothenar Hammer Syndrome: Case Reports and Brief Review

“…Given the universality of use of the hands for hammering in the workplace, it is noteworthy that hypothenar hammer syndrome is a rare clinical problem. Blum et al 15 point out that the position of the ulnar artery relative to the hamulus (which is quite variable) and the site of the impact over the hypothenar eminence may determine the risk of developing an ulnar artery lesion.…”

“…Blum et al 15 state that an alternative to conventional arteriography for evaluating hypothenar hammer syndrome is multi-detector computed tomography angiography. The authors point out that this technique not only displays pertinent vascular anatomy but can rule out bone abnormalities such as hamate fracture, and can show the relationship of the ulnar artery to the hamulus.…”

Lesiones del nervio cubital en el canal de Guyon: a propósito de 6 casos

“…Apertura del hiato superficial y profundo del canal de Guyon dinopatías, anomalías musculares, gangliones, quistes o tumores) (6,7) .…”