Knee replacement surgery, also known as knee arthroplasty, is a medical procedure aimed at relieving pain and restoring function in a severely damaged knee joint. This article provides a neutral, step-by-step explanation of the typical procedure for informational purposes.
The decision to undergo this surgery is typically considered after other non-surgical treatments have not provided adequate relief from pain or improved mobility. The goal of the procedure is to resurface the parts of the knee joint that have been damaged, most commonly by osteoarthritis, rheumatoid arthritis, or post-traumatic arthritis.
Step 1: Preoperative Preparation and Anesthesia
On the day of the surgery, the patient is prepared for the procedure. This includes administering anesthesia. The type of anesthesia—general, spinal, or epidural—is determined by the anesthesiologist based on the patient’s health and the surgeon’s plan. The surgical team cleans and sterilizes the leg to minimize infection risk.
Step 2: The Surgical Incision
The surgeon begins by making an incision over the front of the knee. The length of the incision can vary but is typically between 6 to 10 inches. This incision provides access to the patella (kneecap) and the knee joint itself.
Step 3: Preparing the Bone Ends
The surgeon moves the kneecap to the side and carefully cuts away the damaged ends of the femur (thigh bone) and tibia (shin bone). This process involves removing the worn cartilage and a small amount of underlying bone. The goal is to create precisely shaped surfaces that will accommodate the artificial implants.
Step 4: Positioning the Implants
The artificial components, which are made from metal alloys, high-grade plastics, and polymers, are then attached to the prepared bone surfaces. The femoral component is fitted onto the end of the femur, and the tibial component is attached to the top of the tibia. A plastic spacer is inserted between these metal parts to create a smooth, gliding surface. The back surface of the patella may also be resurfaced and fitted with a plastic button.
Step 5: Closing the Incision
After the implants are secured and the knee’s function is tested through its range of motion, the surgeon closes the incision with stitches or surgical staples. A drain may be placed to remove excess fluid from the joint area. A sterile bandage is then applied to complete the procedure.
Understanding the Core of the Procedure: A Step-by-Step Breakdown
The phrase “knee replacement surgery” is a common term for a procedure that is more accurately described as a knee resurfacing. The surgery does not involve replacing the entire knee joint with a mechanical hinge. Instead, it is a precise process of removing a few millimeters of damaged bone and cartilage from the ends of the femur and tibia. These are then replaced with artificial surfaces that function similarly to a natural healthy knee. The step-by-step guide illustrates this meticulous process, from incision and bone preparation to the secure placement of the prosthetic components, culminating in the closure of the surgical site.
The implants used are designed to replicate the natural movement of the knee. The materials are chosen for their durability and biocompatibility, meaning they are well-tolerated by the body. The femoral component is typically made of a polished, strong metal, while the tibial component often consists of a metal tray topped with a durable plastic spacer. This combination allows for smooth flexion and extension.
The entire surgery usually takes between one to two hours to complete. The duration can vary based on the individual’s anatomy and the specific surgical technique employed. Following the procedure, the patient is moved to a recovery room where their vital signs are closely monitored as the anesthesia wears off.
Modern surgical techniques may involve the use of computer navigation or robotic-assisted systems. These technologies are tools that can aid the surgeon in achieving more precise alignment and placement of the knee implants. The ultimate goal of using any technique is to enhance the longevity and function of the artificial joint.
Recovery begins almost immediately after surgery. Physical therapy is a critical component of the process, helping to strengthen the muscles around the new joint and restore movement. The success of the procedure depends on a combination of surgical skill, the quality of the implants, and the patient’s commitment to postoperative rehabilitation.
It is important for individuals to have a thorough discussion with their orthopedic surgeon to understand all aspects of the procedure, including its potential benefits and risks. This information allows a person to make a well-informed decision about their treatment options for knee pain.