ANKLE FRACTURES

Isolated fractures of the distal fibula are caused by an eversion/external rotation force through the ankle. With only one component of the articular ring disrupted, these are stable injuries (Figure 18.55).

Figure 18.55

A similar injury combined with a fracture of the medial malleolus or tear of the deltoid ligament (Figure 18.56) is not stable and causes subluxation of the ankle joint.

Figure 18.56

Inversion injuries result in medial subluxation of the joint and fractures of both malleoli (Figure 18.57).

Figure 18.57

A vertical load causes the distal tibial articular surface to fracture (Figure 18.58), resulting in a compression injury to the cancellous bone and significant disruption of the articular cartilage of the ankle.

Figure 18.58

Evaluation

Ankle fractures result from low-energy injuries such as a fall from a low step. Inspection for deformity and palpation of the area of maximum tenderness will enable you to make an accurate diagnosis. X-rays are most useful to evaluate the position of the ankle joint after closed reduction.
The reduction is satisfactory if X-rays show the cartilage clear space has a uniform thickness on all three sides of the joint when viewed in the mortise view (anterior-posterior view with the ankle in 15 degrees of internal rotation) and there is a normal relationship of the distal tibial surface to the talus.

Treatment

Treat isolated fibula fractures in a 3-way splint (see page 17–10), followed after 7–10 days by a weight bearing short leg cast.

Unstable fractures

Reduce unstable fractures with gentle longitudinal traction followed by manipulation in the opposite direction to the deformity:

Vertical load fractures (Figure 18.58), are difficult to treat by closed reduction. If gentle traction and manipulation of the fragments does not result in a satisfactory reduction, consider calcaneal traction or an external fixation frame.