Lower limbs injuries fourth lecture
Dr.Alaa Al-algawy
ANKLE FRACTURES:
Ankle Fractures & Dislocations
Fractures and dislocations of the ankle are among the most common injuries treated by orthopedic surgeons. This injury is seen in all age groups, with a slightly different fracture pattern in children and adolescents than with adults. The ankle joint itself is limited to one plane of motion: plantarflexion and dorsiflexion in the sagittal plane. With incorporation of the motion of the subtalar joint (which allows for inversion and eversion in the coronal plane), the foot is able to move in a complex and varied arc in relationship to the leg.
Fracture-dislocations of the ankle are frequently referred to as bimalleolar (fractures of the medial and lateral malleoli) or trimalleolar (fractures of the medial, lateral, and posterior malleoli). Fracture of the lateral malleolus with complete rupture of the deltoid ligament (Dupuytren s fracture) or fracture of the medial malleolus with complete disruption of the syndesmosis and a proximal fibular shaft fracture (Maisonneuve s fracture) are also considered bimalleolar fractures on a functional basis.
Classification
The purpose of any classification scheme is to provide a means to better understand the extent of injury, describe an injury, and determine a treatment plan. Presently, the two most widely used classification schemes for describing ankle fractures is the Weber classifications.
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The Weber classification is based on the level at which the fibular fracture occurs.
Type A: Fracture in which the fibula is avulsed distal to the joint line. The syndesmotic ligament is left intact.
Type B: Spiral fracture of the fibula beginning at the level of the joint line and extending in a proximal-posterior direction up the shaft of the fibula. Parts of the syndesmotic ligament complex can be torn, but the large interosseous ligament is usually left intact so that no widening of the distal tibiofibular articulation occurs..
Type C: Fracture of the fibula proximal to the syndesmotic ligament complex, with consequent disruption of the syndesmosis. Medial malleolar avulsion fracture or deltoid ligament rupture is also present. Posterior malleolar avulsion fracture can also occur.
Treatment
Four criteria should be met for the optimal treatment of ankle fractures: (1) dislocations and fractures should be reduced as soon as possible; (2) all joint surfaces must be precisely restored; (3) the fracture must be held in a reduced position during the period of bony healing, and (4) joint motion should be initiated as early as possible.
If these treatment goals are met, a good outcome can be expected, keeping in mind that disruption of the articular cartilage results in permanent damage.
Initial treatment of ankle fractures should include immediate closed reduction and splinting, with the joint held in the most normal position possible to prevent neurovascular compromise of the foot. An ankle joint should never be left in a dislocated position. If the fracture is open, the patient should be given appropriate intravenous antibiotics and taken to the operating room on an urgent basis for irrigation and debridement of the wound, fracture site, and ankle joint. The fracture should also be appropriately stabilized at this time.
With the advent of excellent results obtained from the techniques of open reduction and rigid internal fixation as developed by the AO group, the standard of care for displaced ankle fractures has become operative intervention. Exceptions to this rule are nondisplaced, isolated Weber type B lateral malleolar fractures , distal fibular avulsion fractures, fractures in nonambulatory (ie, paraplegic) patients, and fractures in patients for whom the surgical risks are greater than the consequences of non-anatomic reduction of the fracture. The isolated previously described lateral or medial malleolar fractures may be treated in a well-molded short leg walking cast for 6 weeks. Unstable ankle fractures treated by immobilization should be placed in a long leg cast with the knee flexed to prevent weight bearing on the involved limb. Most non-displaced medial malleolar fractures should be treated with internal fixation because of the risk of nonunion, when these fractures are treated non-operatively.
Following surgery, the limb is placed in a bulky sterile dressing with plaster splints from the ball of the foot to the proximal calf to allow for wound healing. The ankle is kept in neutral position to prevent equinus deformity. After the sutures are removed at 1–2 weeks, the surgeon must decide whether to begin early mobilization of the ankle joint.
Outcome
In stable fractures, or those that have been anatomically reduced, the functional outcome is good, and normal function can be anticipated. However, recovery is often slow with prolonged stiffness and swelling being the most common complications. Diabetic patients have a higher complication rate with infection being a particular problem. If this occurs it may be very difficult to treat and amputation is not an unusual result. Post-traumatic osteoarthritis is a well recognized problem, but fortunately is not frequent. Ankle arthritis is treated by ankle fusion if symptomatic. Ankle arthroplasty is an option, but few patients are suitable due to age, post-traumatic deformity and soft-tissue problems.