Delayed degradation in a resorbable plating system

Resorbable plating systems are used extensively for craniofacial reconstruction, particularly in children. The systems provide rigid fixation while potentially minimizing the long-term drawbacks of permanent plating systems such as plate "migration," bone growth restriction, and imaging artifact. However, the need for active plate resorption represents both the strength and weakness of these fixation systems. We present four patients who underwent cranial vault remodeling using a resorbable plating system, following which the plates were palpable and observable for at least 2 years postoperatively. All required surgical removal. On gross inspection, the plates had been replaced by an encapsulated spongy material containing yellow, grainy, cloudy liquid. The bone underlying the plates was depressed and irregular in contour when compared with the adjacent bone. Microscopic studies showed a giant cell foreign-body reaction with crystalline material present in the cell vacuoles.