Heterotopic ossification: a preventable case of gossypiboma in spinal cord injury.

Heterotopic ossification is the formation of ectopic bone in soft tissues. It has three established aetiologies: genetic, traumatic and neurogenic. A gossypiboma is defined as a retained foreign body, such as a mass or sponge, usually after a surgical procedure. In this article, we present a unique, preventable case of a patient admitted for newly developed heterotopic ossification in the gluteus maximus muscle caused by a retained piece of foam from negative pressure wound therapy (NPWT). The heterotopic ossification lesion, together with the retained foreign body, was completely excised and reconstructed using a posterior thigh fasciocutaneous advancement flap. This is the first reported case of heterotopic ossification caused by a retained foreign body and may be helpful to better understanding of the aetiology of heterotopic ossification.