Advantages of internal fixation of patellar claw 1, due to the particularity of its material, the patellar claw has resilience and recovery force, which can act on the patella from 5 to 9 directions, continuous automatic pressure, and the connection body of each claw is located on the surface of the patella, fully in line with the principle of tension band. 2, simple operation, placement and removal without special surgical instruments, shorten the operation time. 3. It has no stimulating effect on soft tissue and reduces the occurrence of complications. Moreover, the three claws below the patellar claw hold and fix the lower pole of the patella in the front, lower and rear three directions, the above two claws are tightly embedded in the upper pole bone of the patella, and the bone block is integrated fixed, and the internal fixation does not affect the joint activity, and the joint flexion and extension function can be exercised early. The complications such as patellofemoral traumatic arthritis and fracture nonunion were avoided.