Knee replacement surgery is a popular orthopedic procedure during which the diseased or damaged joint of the knee is replaced with an artificial joint or prosthesis. It is a common procedure and as many as 580,000 patients in the United States (US) alone undergo knee replacement surgery in a year.
Out of all the knee replacement surgeries, more than 90 percent of the patients report experiencing a considerable improvement in their symptoms such as knee pain, inflammation, and reduced mobility. A majority of patients are able to resume their daily routine within three to six weeks after the date of surgery.
While most patients already know these generic details about the procedure, a majority of them have no idea about the anatomical impact of knee replacement surgery. Knee replacement surgery is not just about the replacement of the damaged knee joint with a prosthesis. Surgeons remove many parts of the knee during the surgery, including a few essential ligaments and cartilages.
The following are the two most important ligaments of the knee affected by total knee replacement surgery. These ligaments are completely removed along with the knee joint bone.
Anterior Cruciate Ligament (ACL)
The ACL is removed along with the cartilage in the knee joint. This ligament is removed after the surgeon pushes the patella aside and removes the meeting ends of the femur and tibia bones. This is done so that these two bones can be reshaped for firm attachment to the prosthesis.
The ACL is responsible for providing a stability to the knee by preventing the tibia from sliding through. Since this function is completely taken over by the prosthesis, the ACL ligament is no longer required after knee replacement. Therefore, the surgeons remove it during the surgery.
Posterior Cruciate Ligament (PCL)
The surgeons are most likely to remove PCL during knee replacement. However, some may decide against it. PCL also stabilizes the knee by preventing the femur from sliding through. Just like in the case of ACL, the function of the PCL is taken over by the prosthesis and as a result, it is no longer required.
What remains unaffected during the surgery?
The lateral collateral (LCL) and medial collateral (MCL) ligaments are left untouched during knee replacement surgery. These two important ligaments prevent the knee from bending sideways. This function is not taken over by the prosthesis, and hence, LCL and MCL help stabilize the knee on top of the support provided by the artificial joint.