Malignant tumors at the site of total hip prosthesis. Analytic review of 46 cases.

During the years 1974 to 2003, a total of 46 cases of malignant tumors at the site of total hip arthroplasty, 41 sarcomas, 4 lymphomas, and 1 epidermoid carcinoma, have been reported in the Western literature. Soft tissue sarcomas occurred in 31 and bone sarcomas in 10 cases. Malignant fibrous histiocytoma was the most common in 20 (65%) of all soft tissue sarcomas. The patients with malignant tumors had been operated on more often for secondary osteoarthritis and had more local complications than those in ordinary total hip arthroplasty series. Primary osteoarthritis was the indication in 63% and secondary osteoarthritis in 37% of the 38 reported cases. Tumor developed after 8 (17%) revisions. Deep infection complicated 4 (9%) of the cases. Four cases (9%) were preceded by a precondition for cancer, 2 postradiation necroses of the femoral head, 1 chronic sinus, and 1 Mafucci syndrome. Mean age of the patients at the time of first implantation was 59 years (range, 24-79 years). The mean latent period was 6 years (range, 0.5-20 years) from the first operation. Longer latency period did not correlate positively with the cancer risk. Sarcomas were highly aggressive. Of the 31 reported patients, 24 (77%) died within 1 year after the diagnosis. The number of reported sarcoma cases is low considering the total population behind the cases. In addition, one observed local sarcoma from Nordic cohorts was less than expected. Chronic, particle-induced inflammation around the prosthesis does not seem to increase the risk for carcinogenesis.