[Fibular nerve compression due to an unusual cause. A case report].

There are many factors causing a compression of the fibular nerve accompanied by a loss of function. We describe an unknown cause: a chronic low-grade infection after implantation of a knee endoprosthesis. Perforation of the capsule of the knee joint followed by discharge of polyethylene particles originating from the endoprosthesis. A granuloma developed which resulted in a compression of the peroneal nerve with sensomotor disabilities. Preoperatively we were not able to define the dignity of the tumour. Neurolysis was performed followed by excision of the tumour. The infection was treated by long term antibiotics without removal of the endoprosthesis. Histological examination revealed the definitive diagnosis.