Patellar comminuted fractures are usually quite severe because once the patella is shattered, it can no longer guarantee a smooth cartilage surface. Moreover, the more severe the fragmentation, the harder it is to restore smoothness. If the smooth surface is not well restored, certain conditions can arise. The first is post-traumatic arthritis, the second is patellar chondromalacia, and the third is patellofemoral arthritis. Therefore, patellar comminuted fractures usually require open reduction and internal fixation surgery. In this surgery, it is crucial to align the cartilage surface of the patella as accurately as possible, making the joint surface as smooth as possible, and then fasten it securely with wire loops or tension bands. If the patellar fragmentation is particularly severe, and it's impossible to restore the integrity of the cartilage surface, it may be considered to remove the patella. If feasible, a prosthetic patella can be installed. If not, the ligaments and joint should be repaired, and then functional exercises should begin three to four weeks post-surgery, although this method of surgery typically results in weakness in extending the knee on the affected side.