Effects of bone cement filling in rabbit proximal femoral medullary cavity on distal femoral blood flow and metabolism

OBJECTIVE: A rabbit model was used to evaluate the effects of bone-cemented hip arthroplasty on distal femoral blood flow and metabolism relative to that of the non-cemented contralateral leg. METHODS: The marrow cavity of the right hind femur was filled with bone cement. At each of the following time points, rabbits were randomly selected to receive an injection of one dose of (99m)Tc-methylene diphosphonate and then immediately scanned using a gamma camera: immediately postoperatively and at 4 and 8 weeks postoperatively. A BL-410 model biofunction experimental system was used to analyze the acquired images and determine the radioactive counts of each hind leg. RESULTS: The X-ray and photographic images of the right femoral bones confirmed successful filling of the marrow cavity with bone cement. The radioactive counts were significantly lower in the experimental than control legs at each time point. The ratio of the radioactive count of the experimental to control leg increased considerably at each time point, but each ratio was <1. CONCLUSION: Blocking the proximal femoral medullary cavity with bone cement was associated with significant lowering of the blood circulation of the femur and marrow, decreasing the distal femoral blood flow and bone metabolic rate.