Waterproof cast liners are often used when applying a spica cast for the management of femur fractures in children in order to improve ease of care.
We identified one High Quality study48 that addressed the use of waterproof liners in spica casts. Use of a waterproof liner was associated with significantly fewer skin problems and unexpected cast changes. However, in this study spica casts were used for the management of developmental dysplasia of the hip, not specifically for diaphyseal femur fractures. In addition, other outcomes such as impact on family and financial considerations were not studied. Waterproof liners may make cast care easier for the family, thus decreasing the overall impact of treatment on family functioning. Cast liners add increased cost to overall management. Nevertheless, the patient ages were similar to the patient ages for spica cast management of diaphyseal femur fractures and the findings should be able to be extrapolated. The overall benefit in terms of skin problems, unplanned cast changes, and ease of care for the family likely obviates the increased costs from the use of waterproof cast liners in the expert opinion of the physician work group.