Most ankle fractures are caused by indirect violence, such as valgus, pronation or external rotation. Different types and degrees of fractures are produced depending on the size and direction of the violence and the position of the foot at the time of injury. The ankle joint is a weight-bearing joint and all fractures are intra-articular. If the alignment is not good, traumatic ankle arthritis will be formed and the injured ankle will be stiff and painful and difficult to walk.
I. Etiology
Ankle fractures are mostly caused by indirect violence. The classification of ankle fracture varies, but the original fracture classification is relatively simple, such as stable and unstable fractures according to the fracture pattern or single, double and triple ankle fractures according to the fracture area.
Clinical manifestations
1. Symptoms Severe pain and deformity in the ankle, followed by swelling and subcutaneous bruising. Patients cannot walk, and in severe cases, the circulation of the foot is impaired.
2. Physical signs Routine physical examination will aggravate the pain, so the physician should be gentle during the examination. After there is tenderness in the injured area, further auxiliary examination will be used to confirm the diagnosis.
C. Classification
The causes of fracture are classified as internal, external, external rotation and vertical compression, and Lauge-Hansen classification Lauge-Hansen classifies ankle fractures into 5 categories through autopsy and clinical practice. This classification can reflect the posture of the foot at the time of injury, the direction of external force, the association between ligament damage and fracture, and can also clarify the severity of the fracture, which is useful for guiding the manipulation and rehabilitation, but it is more complicated.
IV. Examination
Auxiliary examinations.
In general, the correct diagnosis and classification can be obtained by taking ortho-lateral x-ray of the ankle joint. When taking an orthopantomograph, the lower leg should be internally rotated by 20° so that the axis through the ankle joint is parallel to the x-ray. On this ankle orthopantomograph, the normal ankle joint can be seen as.
(1) The ankle joint gaps are parallel and equally spaced.
(2) The “Shenton” line of the ankle joint is smooth and non-stepped. The so-called “Shenton” line refers to the joint surface of the lower tibia, the outline of the dense subchondral bone, through the joint gap of the lower tibiofibular ligament, and a small bony prominence on the medial side of the fibula, forming a continuous arc. The small supra-fibular eminence is directly opposite the level of the subchondral bone of the inferior tibiofibular articular surface.
(3) The distal end of the lateral articular surface of the talus and the distal crypt of the fibula (where the peroneal tendon is located) also form a continuous arc
In the case of ankle fracture, a 20° internally rotated orthopantomogram of the lower leg shows.
(1) The ankle joint surfaces are not parallel and unequally spaced.
(2) The above “Shenton” line has changed in steps and is not articulated.
The distal end of the lateral talar articular surface is not in a continuous arc with the fibular saphenous fossa.
2.Computed tomography (CT) CT can distinguish the coronal and sagittal fracture lines of the ankle joint and certain microfractures that are not easily detected on ordinary X-rays. It can be considered as an option if necessary.
If necessary, take radiographs under stress after anesthesia. Take orthogonal lateral radiographs of the ankle joint under stress in internal rotation, external rotation, dorsiflexion and plantarflexion as needed.
V. Treatment