LARGE AMOUNTS OF POLYETHYLENE DEBRIS IN THE INTERFACE TISSUE SURROUNDING BIPOLAR ENDOPROSTHESES - COMPARISON TO TOTAL HIP PROSTHESES

A histologic and biochemical comparison of interface membranes around femoral components of bipolar endoprostheses (n = 17) and total hip pr ostheses (n = 17) inserted without cement was conducted. The patients' profiles were similar in both groups with respect to age, sex, primar y diagnosis, weight, and the interval between primary and revision art hroplasty. Macroscopically, marked circumferential abrasion of the pol yethylene insert in the retrieved bipolar cups was noted. Histologic a nalysis revealed significantly larger amounts of polyethylene debris i n the bipolar group. The membranes from the bipolar group also produce d significantly greater amounts of prostaglandin E(2) (P < .05). The i nflammatory membranes associated with large amounts of polyethylene de bris may have contributed to aseptic loosening and osteolysis in patie nts with a bipolar hip prosthesis.