Lunate dislocation

Introduction to lumbar dislocation The shape of the lunate bone is special, and the wide side of the volar side is narrow. The proximal end forms a joint with the tibia, the distal end forms a joint with the head bone and a small portion of the hook bone, and the temporal side forms a joint with the scaphoid, the ulna and the triangular bone. After dislocation, it completely moved to the volar side, and the blood supply of the lunate bone came from the anterior ligament and posterior ligament. Mainly manifested as swelling of the wrist. The patient is held in the palm of his hand. When the bone is dislocated, the third metacarpal bone on the side has obvious shortening. The movement of the wrist is limited, the flexion of the finger is difficult, the wrist joint can not be stretched back, the palm of the wrist has tenderness, and the lunar bone can be touched. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: ischemic necrosis osteoarthritis

Cause of lumbar dislocation

External force factor (78%):

Dislocation is caused by indirect external force, the palm of the hand falls, the wrist is in the extreme back extension position, the external force from top to bottom gravity and the bottom-up reaction force, so that the distal bones of the humerus and the head bones are squeezed, the tibia The volar space between the head bone and the head bone is widened, the volar ligament between the head bone and the lunate bone and the joint capsule are ruptured, and the lunate bone is dislocated to the volar side. If the lunate bone remains in place, and the other carpal bones are completely dislocated, it is called dislocation around the lunate bone.

Lumbar dislocation prevention

The disease is mainly caused by trauma, so it is necessary to pay attention to safety and prevent accidental injury. In addition, there are the following points in the diagnosis and treatment: attention should be paid to the avascular necrosis of the lunate bone after dislocation of the lumbar bone, so the diagnosis is confirmed early. Timely closure of the manual reduction or percutaneous Kirschner wire reduction is the key to avoid ischemic necrosis of the lunate bone. For cases of old and long-distance dislocation, the ligament of the dorsal ligament of the palm has been broken. Has been interrupted, become a dead bone, should be removed.

Lumbar bone dislocation complications Complications ischemic necrosis osteoarthritis

The complications of this disease are as follows:

(1) Median nerve paralysis: timely reduction can make the median nerve recover completely in the early stage. If the period is delayed, the recovery may not be complete. However, other treatments are rarely needed.

(2) Sudeck atrophy: this is a common complication of the disease.

(3) ischemic necrosis: can cause lumbar bone collapse and secondary osteoarthritis, the latter progresses rapidly, all patients with bone dislocation should review the X-ray monthly within 6 months after injury, and find out at the same time This complication, if found early, can be removed from the lunate bone to prevent progressive osteoarthritis. For many cases, of course, advanced patients. It tends to undergo wrist arthrodesis. Note that the wrist is repeatedly damaged without accompanying Lumbar dislocation can also have similar X-ray findings (Knbock disease), which is more common in manual workers such as carpenters, shoemakers and repeated use of hammers.

Symptoms of lumbar dislocation common symptoms wrist swelling and palm flexion... interphalangeal joints can not flex the wrist swelling and tenderness

The main manifestation of this disease is swelling of the wrist, which allows the patient to hold the palm of the hand. When the bone is dislocated, the third metacarpal bone on the side has obvious shortening, the wrist activity is limited, the flexion of the finger is difficult, the wrist joint can not stretch, the wrist There is tenderness in the horizontal stripes, and the lumbar bone can be touched. The wrist is biased to the ruler. When the fourth metacarpal bone is slammed, there is obvious pain. The median nerve can also be pressed and the palmar side of the palm is numb.

Examination of lumbar dislocation

In addition to its clinical manifestations, X-ray examination can provide a basis for diagnosis, mainly including positive and lateral films:

(1) X-ray positive position: visible carpal bone arrangement disorder, head bone and moon bone shadow overlap, the celestial interval increases, the long axis of the scaphoid becomes shorter, the cortical ring sign or the scaphoid rotation, the lumbar bone dislocation loses the quadrilateral Structure, with a triangular shadow.

(2) X-ray lateral radiograph: the posterior dislocation of the lumbar bone, the third metacarpal, the head bone and the lunate bone, the humerus loses the normal coaxial relationship, and the axis of the third metacarpal and cephalic bone is located on the lunate and tibia axis. On the dorsal side, on the basis of this, when the lumbar bone is tilted to the volar side, it is suggested that the dorsal lateral dislocation around the lunate bone, and the third metacarpal, cephalic bone, and humerus have the same bearing relationship. The bone is located on the volar side of the above bone axes.

Diagnosis and diagnosis of lumbar dislocation

diagnosis

There is a history of traumatic injury in the palm of the hand. The swelling of the wrist can be seen, the wrist is swollen, the activity is limited, and the median nerve compression syndrome can be accompanied. The X-ray film examination can provide the basis for the diagnosis. The X-ray positive radiograph shows the disorder of the wrist bone. The head bone overlaps with the moon bone. The scaphoid gap increases, the long axis of the scaphoid becomes shorter, and the cortical ring sign or the scaphoid rotates; the lumbar dislocation loses the quadrilateral structure and presents a triangular shadow, and the X-ray lateral piece shows the dorsal dislocation around the lunate bone, the third metacarpal, The head bone and the lunate bone and the humerus lose their normal coaxial relationship. The axis of the third metacarpal and head bone is located on the dorsal side of the lunate bone and the tibia axis. On this basis, when the lumbar bone is tilted to the volar side, it is suggested to be a dynamic lunate bone. Dislocation of the dorsal side of the left side; the metacarpal metacarpal dislocation showed the third metacarpal, the head bone, the humerus had a common bearing relationship, and the lunate bone was located on the volar side of the above bone axes.

The disease should pay attention to the identification of the scaphoid, the dorsal dislocation around the lunate bone and the dorsal dislocation around the lunate bone with the scaphoid fracture.

(1) The difference between the two is the relationship between the proximal scaphoid bone and the lunate bone. If the relationship with the lunate bone remains unchanged, it is the scaphoid, the dorsal dislocation around the lunate bone, otherwise the dorsal side around the lunate bone. Dislocation with scaphoid fracture.

(2) The scaphoid, the head bone, the dorsal dislocation around the lunate bone and the scaphoid syndrome. The former bone bone and the proximal scaphoid bone and the lunate bone remain unchanged, while the remaining carpal bones remain unchanged. Both are dislocated to the dorsal side; the latter is based on the former, the dislocated carpal bone is repositioned due to rebound, and the proximal end of the head bone is rotated, so the proximal end of the head bone is difficult to reset and the blood supply is severely damaged, requiring surgical reduction and reconstruction. Blood transport.

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