Lateral malleolus

Introduction In the axillary joint anterior segment of the axillary joint, the lateral malleolus showed a depression, indicating that the humerus was in the external rotation. The humerus should be examined to exclude the fracture of the tibia. Observe the degree of skin color edema, the patient's action, and vascular abnormalities. The symptoms are mostly complications of trauma, with local swelling, pain, deformity, tenderness and dysfunction as the main manifestations, pay attention to the identification of tibiofibular fractures. Surgery is generally used. If it is only a simple sacral joint ligament injury, it can also be recovered by non-surgical methods.

Cause

The reason why the outer sag is concave:

(1) Causes of the disease

Due to external rotation injury.

(two) pathogenesis

The underarm joint is separated from the front and is caused by external rotation. The anterior portion of the talus pushes the external malleolus, causing it to twist outwards and backwards, and the common anterior tibial tuberosity is avulsed. However, in most cases, the anterior tibial ligament itself is torn. Later, the synovial blind tube behind the ligament is torn and the fiber in the interosseous ligament is broken. When the humerus is externally rotated, the posterior tibial ligament is also stressed, and the posterior lip of the humerus can be avulsed. This point is considered by the scholar as an external rotation. The characteristics of the injury and suggest that the anterior and posterior ridges are also separated. The avulsed bone piece is very small, rarely exceeding 1/4 of the articular surface.

The external rotation force is different in size, and the rupture depth of sputum combined from front to back is also different. If the injury persists, the sacral bone fracture will occur, and the fracture plane will be different. Very few anatomical neck fractures may occur (called Maisonneuve fracture). ). Most of them are distal humeral fractures. Some people call it the sacral or sacral oblique or spiral fracture. Such cases may have a anterior tear in the superficial ligament of the triangular ligament, or a anterior humeral fracture, or a medial malleolus fracture, or a deep and shallow ligament of the triangular ligament.

an examination

Related inspection

Bone bone and joint MRI examination of bone and joint soft tissue CT examination

Acupoint tablets are an important means of diagnosing the joint separation of the underarms. The overlapping shadows B to C of the normal tibia and the anterior tibial tuberosity are not less than 8 mm, or not less than 1/3 of the width of the tibia. Normal tibia joint gap A ~ B should not exceed 3mm. If the foot is externally rotated during the filming, the gap is reduced, and the gap is clearly visible when the foot is rotated. Taking acupoints, the medial space of the ankle is the clearest and widened. Explain that combined anterior tear and medial triangular ligament injury.

Lateral ankle joint: Under the stress, the tibia is pulled forward, the affected foot is pushed backwards, the tibia is moved forward and the talus is moved backwards. Therefore, the lateral anterior slice shows a widening of the anterior ankle gap.

Differential diagnosis

The differential diagnosis of the external hemorrhoids:

Should be differentiated from the fracture of the tibia. The fracture should be excluded first in the diagnosis.

History of trauma, local swelling, pain, deformity, tenderness (+) and dysfunction.

According to the above analysis, the following fractures can be associated with the diagnosis of anterior tibiofibular joint fracture: distal radius fracture; transfemoral combined fracture; avulsion fracture of anterior tibial tuberosity; avulsion fracture of posterior lip of humerus; The medial joint space is widened.

In the calf rotation position, if the ankle joint and the calf are rotated 30°40°, the external ankle is concave on the orthotopic piece of the ankle joint, indicating that the humerus is in the external rotation position. The humerus should be examined to exclude the fracture of the tibia. In addition, it can be used to detect the lateral position of the ankle when the ankle is flexed. If the anterior space of the ankle is not parallel and widened, the anterior collateral tear of the infraorbital joint should be suspected.

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