A patella fracture that has been properly treated for about 50 days is in the period of primitive bone scab formation, and clinical healing of the fracture has not yet been achieved. Patella fractures are mainly comminuted fractures caused by direct violence, or transverse fractures caused by indirect violence. The patella is the largest seed bone in the body and can effectively reduce the force of knee extension. Patella fractures require regular treatment, which can prevent complications such as traumatic arthritis. Around 50 days is in the period of primitive bone scab formation, which lasts about 3 to 6 months. Clinical healing has not yet been achieved, and at this time there is still no ability to bear weight and resist rotation. So it is better to wait until about 3~6 months to review the X-ray and then observe the recovery of the fracture. During the period of bed rest, we should carry out the functional exercise of the knee joint and the exercise of the lower limb muscles. The main purpose is to prevent joint stiffness and lower extremity venous thrombosis.