Goals: Sarcomatous degeneration of giant cell tumours (GCT) occurs rarely. It occurs in less than 1% of the cases, and most of them are GCT previously treated with radiotherapy. The goal of this presentation is to review the CGT cases treated at our unit that have evolved towards malignization.

Methods: Retrospective study of 96 GCT treated at our Hospital between 1983 and 2005. 5 presented sarcomatous degeneration in their evolution. These were the cases of 3 men and 2 women with a mean age of malignization of 42 years (32 years – 54 years). The median follow-up period was 155 months (5 months – 209 months). 3 cases affected the distal femur, one case affected distal radius and one case affected proximal humerus, with a slight tendency to the right hemibody. The primary treatment for GCT in these patients was curettage and bone graft. Only one case had received previous radiotherapy. In the same period of time we had two cases of lung dissemination of CGT with typical histology, without previous malignization of tumour.

Results: Malignization takes place, on average, at the 1.8th recurrence (1.3). Histologically, we find 3 osteosarcomas and 2 indifferentiated tumours. Three patients developed distant dissemination; 2 patients died due to lung metastases, with a mean time between the first surgery and the sarcomatous degeneration of 90 months (40 monts – 183 months) and a mean time between malignization and mestastases of 22.3 months (9 months – 34 months) The treatment, once the malignization was diagnosed, consisted in wide resection and substitution with mega-arthroplasty in cases of distal femur and osteoarticular graft at the shoulder. 2 cases required amputation of the affected limb due to irresecable recurrence in soft tissues.

Conclusions: There is no predictive criteria of which type of primary typical CGT will evolve into sarcoma. The malignization always has as a result high grade sarcomas, with a high tendency to hematogenous dissemination. When lung metastases appear the survival prognosis is a number of months. We must suspect malignization of a benign CGT when one of the relapses shows a very rapid growth with radiologic aggressive characteristics; in these cases we prefer wide resection of the tumour instead of curettage and thus we prevent the possible sarcomatous degeneration.

Introduction: Hip replacement prosthesis infection is a severe complication of ever increasing incidence. Currently there is controversy as to whether prosthetic revision surgery should be carried out in one or two stages and whether cemented or uncemented prostheses should be used.

Materials and methods: This is a retrospective study of 17 cases of chronic infections of hip replacements that were revised in one-stage procedures between 1996 and 2005 in our center. Mean follow-up is 3.4 years. We analyzed the functional status of the hips before and after revision using the Merle D’Aubigne scale, x-rays, and supplementary tests for diagnosis and decisions on treatment.

Results: The functional score at the end of the follow-up was 16.17 (Merle D’Aubigne scale). The most common pathogen is coagulase-negative staphylococci. Acute phase reactive elements reached normal levels. X-ray control does not show any alterations or signs of loosening. No subsequent revisions have been performed.

Conclusions: The diagnosis and treatment of prosthetic revision requires correct preoperative assessment and planning. Differential diagnosis of aseptic versus septic loosening in chronic infections is complex; in some cases it is necessary to wait for definite culture results for a surefire diagnosis. We think that in selected chronic cases of septic loosening of the hip due no non-multi-resistant organisms, one-stage revision using a Wagner osteotomy for diaphyseal cleaning combined with a hydoxyapatite-coated stem makes it possible to achieve good functional results and control infection, decreasing the morbidity and cost of a two-stage revision.