Septic arthritis as a late complication of carcinoma of the breast.

OBJECTIVES To see if a past history of radiation therapy is a risk factor for septic arthritis. METHODS We retrospectively searched our records of 282 patients with septic arthritis and found 10 cases of septic arthritis post-radiotherapy, all in females. We analysed our group, correlating them with the literature. We also compared our patients with a group of septic arthritis patients without radiation therapy. RESULTS Nine had had radiation therapy for carcinoma of the breast. The shoulder joint was involved in six and the sternoclavicular joint in three. The tenth patient had had brachytherapy and radiation for carcinoma of the cervix and presented with septic arthritis of the hip. The mean age of the patients was 69 yr (49-82 yr). The mean time elapsed since radiation was 16 yr (3-34 yr). Twenty-three cases of shoulder septic arthritis in patients without past radiation therapy were selected for comparison. The five patients with past radiation therapy had fever less often and a longer time lapse before diagnosis. They required longer antibiotherapy. However, this prevented neither bone destruction nor relapse. CONCLUSIONS In our study, a past history of radiation therapy was observed in 6/50 infections of the shoulder, 3/5 infections of the sternoclavicular joint, 6/23 cases of septic arthritis of the shoulder and all cases of septic arthritis of the sternoclavicular joint for females. Radiation therapy seems to be a risk factor for septic arthritis. Diagnosis would be aided by a greater awareness of the clinical and radiological features of this septic arthritis.