Research shows that if the angle between the patellar tendon and the tibial plateau could be reduced to a perpendicular (90 degree) angle, then weight-bearing strain would be redistributed so that the joint would be stabilized and the CCL would not be needed. The TTA involves an osteotomy (a cut made in bone) in the non-weight bearing portion of the tibia, just behind the tibial tuberosity. The tibial tuberosity is advanced to align the patellar tendon perpendicular (90 degrees) to the tibial plateau slope. This new alignment eliminates the need for a CCL and results in a stable joint. The advanced tibial tuberosity is secured using titanium implants. A bone graft is packed in the open area of the osteotomy to speed up healing which takes about 8 weeks.