A follow-up study regarding the occurrence of segmental collapse of femoral head has been done in 53 patients of united femoral neck fracture including a periodic examination by 99mTc-MDP scintimetry. The results showed that the sequential variations in the nuclide uptake ratio of the femoral heads could reflect the histological repairing process and metabolic level in the femoral head. A sustainedly high nuclide uptake in 12 months after operation often denotes that there are defects in the repairing process of the ischemic femoral head, and that the segmental collapse of the femoral head will ensue.