[Early diagnosis by scintigraphy of segmental collapse of the femur head following femur neck fracture]

In order to obtain an early prediction for segmental collapse of the femoral head after femoral neck fracture, we have studied in 53 cases of the femoral neck fracture using 99mTC-MDP scintimetry. According to the radionuclide uptake ratio of the femoral heads, we can estimate the gravity of the avascular necrosis of the femoral head after fracture and recognize the repair process in the necrotic head. Fifty-three cases of fresh fracture were examined by sequential scintigraphy before operation and during follow up examinations after operation. The radionuclide uptake were all increased in 3 to 4 months after operation as comparing with that done before operation. The uptake ratios in 37 cases decreased gradually and approached 1 in 12 months after operation. All of them have an excellent result during follow up examination 36 months after surgery. The uptake ratios in 19 cases were also increased after operation, but still maintained at a high level in 6 to 12 months. They all showed radiographical signs of segmental collapse 18 to 24 months after operation. These results showed that uptake ratio of the radionuclide bone imaging is able to predict the occurrence of segmental collapse of the femoral head after femoral neck fracture. The time of the diagnosis by scintigraphy for segmental collapse of the femoral head is earlier than that by radiography.