Intrapelvic pin migration after periacetabular reconstruction and arthroplasty of the hip in metastatic pelvic disease—a case report

In January 1997, a 62-year-old man was diagnosed with a hypernephroma of the right kidney and bilateral pulmonary metastases. He underwent a right nephrectomy as initial surgery. Histology showed a 16-mm granular cell renal carcinoma of the lower part of the right kidney. He received chemotherapy with α-interferon for the following 11 months. In November 1999, CT showed a 4-cm osteolytic lesion from the right posterior inferior iliac spine to the roof of the acetabulum. The medial and lateral bony borders were partially destroyed and the lesion was therefore classified as class III according to Harrington (1981).

The patient underwent local radiation therapy in December 1999, and a second course of chemotherapy with vinblastine. Immune modulation therapy with α-interferon showed a partial remission of the pulmonary metastases. In addition, he received intravenous treatment with bisphosphonates.

In February 2000, the patient sustained a pathological fracture of the right iliac wing with medial and cranial dislocation of the entire acetabulum.A second course of radiation therapy was given in August 2000.

In April 2001, the patient presented with an advanced right periacetabular fracture (Figure 1). A periacetabular reconstruction and a total hip arthroplasty was performed. A reinforcement cage (Burch-Schneider, Protek, Switzerland) was combined with a cemented standard stem with a 28-mm metal ball head and cemented polyethylene inlay. After reduction of the fracture, structural continuity was achieved and reinforced with 3 Steinmann pins using the compound osteosynthesis technique, i.e. the pins were entirely covered with bone cement, which filled the gap. 1 pin was inserted from the superior iliac crest to the cranial part of the acetabulum, and 2 pins through the center of the acetabulum. One of these pins was unthreaded (Figure 2). The pins were cut off flush with the iliac crest.