AN EXPERIMENTAL STUDY ON BLOOD FLOW RATE IN THE FEMORAL BONE MARROW CAVITY AFTER PROSTHETIC HIP REPLACEMENT

Abstract

The purpose of this study was to evaluate the effect of using cement on blood flow through the femoral marrow cavity of dogs after prosthetic hip replacement. Blood flow was measured by a direct method on the proximal and distal sides. A section was designed around the 1 cm distal part from the stem tip of the prosthesis. Test experiments were carried out on the left side femur : (1) prosthetic hip replacement using cement (cement group, n=15), (2) similar to (1) but without cement (no cement group, n=15). In both experiments, the intact right femur served as a control (control group, n=30). Blood flow was measured immediately postoperatively and 1, 3, 6, and 12 weeks after the operation. In the test experiments, there was no significant difference in blood flow between the weeks, and mean blood flow values for each week were calculated. The blood flow rates on the proximal side were 2.26±0.31g/min/100g (Mean±SE) in the control group, 0.76±0.26g/min/100g (p<0.0002) in the no cement group and 0.02±0.01g/min/100g (p<0.0001) in the cement group. There were significant differences between these values. The blood flow rates on the distal side were 1.40±0.18g/min/100g in the control group, 0.83±0.20g/min/100g in the no cement group and 0.92±0.30g/min/100g in the cement group. It was found that about 2/3 of the blood flow in the femoral marrow cavity was supplied from proximal side and about 1/3 on the distal side. It was noted that blood flow from the proximal side was almost completely suppressed by using cement, whereas about 1/3 of the blood flow in the control group was preserved without using cement. These results indicate that it is better to perform prosthetic hip replacement without using cement.