A below-knee cast or short leg splint provides sufficient stability for most stable metaphyseal distal tibial and fibular injuries and allows mobilization of the knee.
It can be used for potentially unstable fractures, provided they are kept under close surveillance.
It can also be used following closed reduction or surgical fixation in the early postoperative period.
If severe swelling prevents application of a circumferential cast, a temporary splint may be applied as an alternative.
With the knee flexed, apply padding around the leg and slabs of casting material posteriorly, covering half of the circumference.
Secure the splint with an elastic bandage.
A long leg cast may be required to provide more stability and prevent the child from weight-bearing on the injured leg.
This is typically changed to a below-knee walking cast when the fracture is sufficiently stable.
Closed reduction of distal tibial and fibular fractures may be difficult. Support from at least one assistant, providing countertraction and stabilizing the proximal leg, may be helpful.
Place the patient in a supine position on a radiolucent table.
Put a bolster or triangle underneath the knee.
The water temperature should ideally be between 22° and 25° C.
With the knee flexed and stabilized, apply longitudinal traction through the foot. An ankle traction set may be helpful in older children.
Correct translation and angulation of the fracture, and confirm reduction clinically and with an image intensifier if available.
The position of the foot and ankle is important in some metaphyseal fractures.
Placing the foot and ankle in a neutral position may produce an apex posterior deformity in unstable fractures.
An assistant supports the knee.
The cast extends from just below the knee to the base of the toes.
Apply a tubular bandage and cut it slightly longer than the length of the final cast.
The assistant holds the toes, not the stockinette, with the ankle in a neutral position.
Consider adding thick felt over the padding at the malleoli, tibial crest, heel, and the free edges of the cast.
Apply cast padding without creases, overlapping each layer by 50%.
In distal metaphyseal tibial fractures, there is a tendency to produce an apex posterior deformity if the ankle is stabilized in a neutral position. The ankle can therefore be initially immobilized in plantar flexion and changed to neutral after the initial phase of fracture healing.
Apply the first layer of cast material and overlap each layer by 50%.
Avoid sharp edges at the ends of the cast. Make sure the upper end of the cast is well below the popliteal fossa.
Apply further layers of cast material to produce sufficient stability.
Avoid pressure over the fibular head and neck by adding sufficient padding and shortening the cast to prevent injury to the peroneal nerve.
Fold the tubular bandage and padding over the edges of the cast before applying the final layer of casting material.
After cast application, check the fracture configuration with x-rays in both planes.
Parents/carers should understand the following precautions and instructions:
Non-weight-bearing or touch weight-bearing is encouraged for unstable injuries.
Older children may be able to use crutches or a walker.
Younger children may require a period of bed rest followed by mobilization in a wheelchair.
Routine pain medication is prescribed for 3–5 days after injury if required.
The patient should be examined frequently to exclude neurovascular compromise or evolving compartment syndrome.
The first clinical and radiological follow-up is usually undertaken 5–7 days after injury to confirm fracture stability.
Physeal and metaphyseal fractures heal rapidly, and the cast is typically removed 3–6 weeks after injury.
After cast removal, graduated weight-bearing is usually possible.
Patients are encouraged to start range-of-motion exercises. Physiotherapy supervision may be necessary in some cases but is not mandatory.
Activities that involve running and jumping are not recommended until full recovery of local symptoms.