ACL reconstruction is surgery to rebuild the ligament in the center of your knee with a new ligament. The anterior cruciate ligament (ACL) keeps your shin bone (tibia) in place. A tear of this ligament can cause your knee to give way during physical activity.
Ankle replacement is surgery to replace the damaged bone and cartilage in the ankle joint. Artificial joint parts (prosthetics) are used to replace your own bones. There are different types of ankle replacement surgeries.