TISSUE REACTION TO METAL ON METAL TOTAL HIP PROSTHESES

The periprosthetic tissue reaction to polyethylene wear debris in meta l on polyethylene total hip replacements is strongly implicated as the cause of osteolysis. This has led to a renewed interest in metal on m etal total hip replacements. However, little is known about the role o f wear debris in failures of these prostheses, Capsular and interface tissues from 9 long and short term metal on metal total hip replacemen t retrievals were studied to assess the tissue reaction around these p rostheses, As compared with metal on polyethylene cases, the extent of the granulomatous inflammatory reaction and the presence of foreign b ody type giant cells was much less intense in metal on metal cases, li kely because of the lower numbers and overall smaller size of metal we ar debris particles, This may lead to a better transport of the partic les from the joint tissues and a lower incidence of periprosthetic ost eolysis around metal on metal hip replacement.