Prevention of loosening in total hip replacements using guided bone regeneration

The aim of this study was to prevent wear debris from reaching the interfac e of the acetabular cup and femoral component by using a partially occlusiv e expanded polytetrafluoroethylene membrane. This membrane initially acted as a physical seal, which became incorporated by bone and soft tissue, form ing a secondary biologic seal, preventing loosening, An animal model was de veloped to test the hypothesis. The model replicated the mechanisms of loos ening where the effects of wear debris were studied. Using femoral heads wi th the appropriate roughness, a goat model produced the radiologic and hist ologic presentation of loosening as observed in total hip replacements in h umans. Loosening was assessed by measurement of the radiolucent lilies, and was attributed to wear debris by histologic investigation, The expanded po lytetrafluoraethylene membrane prevented acetabular implant loosening to a statistical significance of 0.02 in a blinded assessment when compared with the control groups, Loosening of the first 5 mm of the proximomedial aspec t of the femur also was prevented. The authors of the current study prevent ed wear particle-induced osteolysis in the acetabular component by using an expanded polytetrafluoroethylene membrane to seal the bane-cement Interfac e.