Casting material: synthetic material, if available, is preferable to plaster of Paris, for sanitary reasons
Hip spica box
Folded towel as abdominal spacer
A generous length of tubular bandage is cut to dress the injured leg and a larger diameter tube for the torso. Sewing the two parts of the tubular bandage together prevents separation of the bandages as the child is moved.
The back support for the spica box is placed inside the torso tubular bandage, directly against the skin of the child's back.
Placement on hip spica box
The anesthetized child is transferred onto the hip spica box. It should be ensured that enough people are available to help positioning and stability.
The child’s sacrum should rest on the back support with its perineum against the padded post. The shoulders should be supported by the spica box leaving almost the entire torso free for casting.
The back support can be secured to the apparatus with tape.
Pitfall: Avoid inadvertent extubation during transfer and casting. Discuss airway management with the anesthetist beforehand.
For a younger child, the most convenient position for a protective spica cast is about 45° of hip flexion, 30° of hip abduction, and 70° of knee flexion. This allows for comfort whilst lying and also sitting.
Single-leg vs two-leg spica
A single-leg spica is adequate for most circumstances; some surgeons prefer to apply a short leg on the uninjured side as this can help to make the cast more stable.
A folded towel is placed over the central abdomen, inside the tubular bandage, to create space in the cast for breathing. The tail of the towel is brought towards the neck for ease of removal.
A layer of cast padding is applied, using a larger width for the body and a narrower one for the leg(s).
The cast extends from the nipple line, or just below, to just above the malleolus of the ipsilateral ankle.
Optionally, thick felt can be added over the padding where the chest and leg edges of the cast will be.
A first layer of cast material is applied to leg and body sections, taking care to connect leg to body securely, in a figure of eight (spica technique).
Reinforcing slabs of casting material may be applied between the body segment and the leg segment.
Tubular bandage and padding are folded over the edges before applying the final layer of casting material.
The child is transferred from the spica box and the abdominal towel and the back support are removed from the cast.
The edges of the cast are trimmed, as necessary, to allow flexion of the opposite hip and adequate access to the perineal area.
Optionally, waterproof adhesive tape is added to the perineal edge of the cast.
A hole may be cut in the abdominal portion of the cast to allow for greater comfort with breathing and eating. This is especially important for older children.
If the child has respiratory distress from a cast that has been applied to tightly, it can be split down the side and spread to allow for expansion or it can be removed and reapplied.