What Are The Different Types Of Knee Replacement Surgery?

Conditions such as osteoarthritis, rheumatoid arthritis, or injury to the knee joint can cause severe knee pain and immobility. 

These conditions break down the cartilage between the surfaces of adjoining bones, causing the bones of the knee (the patella, femur and tibia) to move against each other without proper padding. 

Knee replacement surgery, also known as knee arthroplasty, is a procedure that involves removing damaged parts of the knee joint and replacing them with artificial components made of metal, plastic or ceramic. 

It is only recommended once non-surgical treatments have ceased to work to reduce pain and improve immobility. 

What Are The Different Types Of Knee Replacement Surgery?

Each patient’s situation is different, and surgeons are able to tailor the surgery and treatment plan according to each patient’s needs. 

Knee replacement surgeries generally vary with respect to how much of the knee joint is removed and replaced, which specific parts are removed and replaced and the tools used during the surgery. 

Total Knee Replacement

Total knee replacement is the most common type of knee replacement surgery. It involves removing the damaged cartilage and bone from the knee joint and replacing it with a prosthetic implant made of metal and plastic.

During the surgery, the surgeon makes an incision in the knee and removes the damaged cartilage and bone. 

The artificial components, which are designed to replicate the shape and function of the natural knee joint, are then secured to the remaining bone using specialised cement or through a process called "press fit" that allows the bone to grow into the implant.

The procedure typically takes around 1-2 hours to complete and is performed under general anaesthesia or spinal anaesthesia. After the surgery, the patient is monitored in a recovery room for a few hours before being transferred to a hospital room or discharged home, depending on the individual case.

Partial Knee Replacement 

The knee joint is divided into three compartments: the medial (inner), lateral (outer), and patellofemoral (between the kneecap and thigh bone) compartments. When only one compartment is affected by arthritis or injury, partial knee replacement may be an option. 

Partial knee replacement surgery, also known as unicompartmental knee arthroplasty, is an orthopaedic procedure used to treat the damage of one part (compartment) of the knee joint. In contrast to total knee replacement, which involves replacing the entire knee joint, partial knee replacement involves replacing only the damaged or arthritic portion of the knee joint.

During the procedure, the surgeon makes a small incision and removes the damaged portion of the knee joint and replaces it with an artificial implant. The implant consists of a metal component that attaches to the end of the bone and a plastic spacer that sits between the metal component and the opposing bone surface.

Partial knee replacement surgery is a less invasive option compared to total knee replacement, as it involves smaller incisions, less bone removal, and generally shorter recovery time. It is typically recommended for patients who have arthritis or other damage in only one compartment of the knee joint, have intact ligaments, and have not had previous knee surgery.

Revision Knee Replacement 

Revision knee replacement surgery is a procedure performed to replace a previously implanted artificial knee joint that has become damaged, worn out, or infected. This surgery is more complex and challenging than the initial knee replacement surgery because the surgeon must first remove the existing implants and any surrounding bone and tissue that may be affected by the previous surgery.

Revision knee replacement surgery may be necessary for several reasons, including loosening of the implant, wear and tear of the implant, infection, implant breakage, instability, or bone loss. 

The goal of revision knee replacement surgery is to restore function and alleviate pain by replacing the damaged or failed implant with a new one.

The procedure may involve the use of specialised implants, bone grafts, and other techniques to restore the function and stability of the knee joint. The recovery process following revision knee replacement surgery may be longer and more difficult than the initial surgery, and rehabilitation and physical therapy is often required to help the patient regain strength, mobility, and function.

Custom Knee Replacement: 

Custom knee replacement surgery, also known as personalised knee replacement, uses advanced imaging technology and computer-aided design to create a customised implant that is tailored to fit the unique anatomy of each patient's knee.

The process of custom knee replacement surgery begins with a detailed examination of the patient's knee using imaging technology, such as MRI or CT scans. These images are then used to create a 3D model of the patient's knee joint, which can be used to design a personalised implant that closely matches the size, shape, and contours of the patient's natural joint.

The custom implant is manufactured using specialised computer-aided design and manufacturing (CAD/CAM) technology, which allows for precise and accurate placement of the implant during surgery. This can help to improve the overall outcome of the surgery, including reducing pain and improving mobility and function.

Custom knee replacement surgery may be recommended for patients who have complex knee anatomy, such as those with severe bone deformities or unusual joint angles, or for patients who have previously undergone knee surgery and require a revision surgery. 

Custom knee replacement surgery is often used in conjunction with minimally invasive surgical techniques, which can help to further reduce pain, scarring, and recovery time.

While custom knee replacement surgery can offer several benefits over traditional knee replacement surgery, it is not suitable for all patients. 

Minimally Invasive Knee Replacement 

A minimally invasive knee replacement uses a smaller incision than traditional knee replacement surgery, but the procedure still involves the removal of damaged bone and cartilage from the knee joint and replacing it with artificial components. 

The main difference between minimally invasive knee replacement and traditional knee replacement is the size of the incision. In minimally invasive surgery, the incision is much smaller than in traditional knee replacement surgery. 

This smaller incision allows for less disruption of surrounding tissues, muscles and tendons, resulting in less pain, faster recovery times, and smaller scars.

Minimally invasive knee replacement surgery can be performed using traditional surgical instruments or specialised surgical tools that allow for greater precision and control. Some minimally invasive techniques use computer-assisted navigation to ensure the accurate placement of the artificial joint components.

Not all patients are candidates for minimally invasive knee replacement surgery, and the decision to use this technique depends on the patient's age, overall health, the extent of knee damage, and the surgeon's preference and experience. In some cases, traditional knee replacement surgery may be necessary to achieve the best outcome for the patient. 

Bilateral Knee Replacement 

Bilateral knee replacement is when both knees are replaced at the same time. This may be recommended if both knees are severely damaged and require surgery. 

Bilateral knee replacement surgery might limit mobility during recovery, but the overall recovery time for both knees is shorter than if the knees were operated on at different times. 

Understanding The Different Types Of Knee Surgery Available

All knee replacement surgeries involve removing damaged parts of the knee joint and replacing them with artificial implants. 

Knee replacement surgeries are distinguished by how much of the joint is replaced and what types of tools are used during the surgery.