Thumb and index finger cannot form a perfect "O" shape

Introduction The thumb and forefinger cannot form an intact "O" shape on the palm, which is a clinical diagnosis of ulnar nerve injury. After the ulnar nerve injury, the ulnar side, the little finger, and the ulnar side of the hand disappeared, and the movement disorder was combined, and the special movement could not be completed.

Cause

(1) Causes of the disease

1. Crush injuries are the most common and cause direct violence. Nerve injuries are often severe, often accompanied by nerve defects.

2. Pulling injuries such as elbow internal humeral fractures, forearm ulna and radius fractures, and ulnar metacarpal fractures can directly cause ulnar nerve injury.

3. At the elbow, the ulnar nerve can be directly traumatized or combined for fracture dislocation.

4. Wrist and elbow cuts are more common.

5. If you do not pay attention to the protection during general anesthesia, the arm will hang over the side of the operating table, which may cause paralysis due to oppression.

6. In the cervical rib or anterior scalene muscle syndrome, the ulnar nerve is the most damaged.

an examination

Related inspection

Over-finger test finger test Fisher finger test

(1) Exercise.

Injury on the elbow, the ulnar wrist flexor and the deep flexor ulnar side of the ulnar, atrophy, can not bend the wrist to the ulnar side and the distal knuckle of the flexor ring. When the finger is flat, the little finger can't climb the desktop. The internal muscles of the hand are extensively paralyzed, and the small fish, interosseous muscles, and the 3rd and 4th sacral muscles, the adductor adductor muscle, and the medial head of the buckling short muscle are uniform. There is a significant depression between the small fish and the metacarpal. Ring fingers and little fingers have claw-shaped deformities. The claw-shaped malformation on the elbow is lighter; if the deep flexor muscle supplies the distal injury, the deep flexor loses the antagonistic effect of the internal muscle, and the claw-shaped deformity is obvious, that is, the metacarpophalangeal metacarpophalangeal joint is overextended and interdigitated. Joint flexion. It is not possible to straighten the interphalangeal joint while flexing the metacarpophalangeal joint. Due to the antagonistic effect of the temporal sacral muscles, the middle finger of the diet has no claw deformity or only slight deformity. Each finger cannot receive an abduction. The paper jam test was positive. The thumb and forefinger can't form an intact "O" shape on the palm. These two fingers show weakness in the pinch test, which is caused by the internal femoral tendon spasm and the instability of the thumb metacarpophalangeal joint. The little finger and the thumb are pinching the obstacle. Due to the tendon in the hand, the grip strength of the hand is reduced by about 50%, and the flexibility of the hand is lost.

(B) feeling.

The ulnar side of the hand, the little finger, and the ulnar side of the ring all disappeared.

Differential diagnosis

Median nerve injury: supracondylar fracture of the humerus can cause compression injury of the median nerve. After the reduction, the fracture can often recover spontaneously. The thumb, the middle finger can not flex, the thumb can not be abducted, and the palm of the palm of the hand is half-finger. .

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.