In vivo femoral intramedullary pressure during uncemented hip arthroplasty

There is evidence in several animal and human studies that high intramedull ary pressure in the femur is of causal significance for bone marrow release into the circulation, causing pulmonary fatty marrow embolization. A previ ous clinical study provided evidence that in uncemented hip arthroplasty, h igh intramedullary pressure and subsequent fat embolism with cardiorespirat ory deterioration can occur. In this prospective clinical trial, the effect of five surgical techniques on the femoral intramedullary pressure was rec orded intraoperatively in 36 patients during uncemented press fit hip arthr oplasty. in Group A, the conventional surgical technique (slide hammer and femoral rasps) showed intramedullary hypertension during opening of the fem oral canal, femur preparation, and prosthesis insertion. In Group B, a mech anical high frequency vibration rasp was used, instead of the slide hammer, and provided reduction of the intramedullary pressure peaks during opening of the femoral canal but could not prevent intramedullary hypertension dur ing rasping and prosthesis insertion. In Group C, a modified surgical techn ique to prevent high intramedullary pressure reduced pressure peaks during opening of the femoral canal and resulted in a significant reduction of int ramedullary pressure during femur preparation and prosthesis insertion comp ared with the conventional surgical technique used with Group A. In Group D the results of the modified surgical technique could be improved additiona lly by using the high frequency vibration rasp, instead of the slide hammer . In Group E conventional surgical technique in combination with a distal v enting hole has not proven to be efficient in uncemented hip arthroplasty. Based on the results of this in vivo study, the proposed modified surgical technique in cementless hip arthroplasty can be recommended to avoid high i ntramedullary pressure peaks, which should minimize the risk of significant bone marrow release into the circulation and the risk for cardiorespirator y deterioration caused by fat embolism.