The goal of total knee replacement surgery has not changed in the 50 years since the procedure’s inception, but new technology available to surgeons allows for more precision and customization than traditional knee replacement.

Advances in technology and surgical technique, along with enhanced perioperative pain control, also have driven a shift to outpatient total knee replacement procedures. More than half of shoulder, knee and hip replacement surgeries will be outpatient by 2026, according to some estimates.

The objective of total knee replacement is to bring pain relief and improved function — allowing a return to activity — by removing and replacing the diseased or worn articular portions of the joint.

Current and future technological advances for total knee replacement include:

Robotic-assisted and image-guided, computer-assisted surgery

While there are a variety of robotic- or computer-assisted systems available, they all share the common technique of using real-time imaging and computer assistance to guide resection and implant placement, taking into account an individual patient’s anatomy.

“Image-guided and robotic-assisted surgery allows surgeons to perform procedures with a higher degree of reproducible precision,” said Cyna Khalily, M.D., medical director of orthopedic surgery and adult reconstructive surgery at Norton Orthopedic Institute and the first person in the world to perform a Food and Drug Administration-approved cementless total knee replacement with the CORI robotic-assisted system.

Whether preoperatively or intraoperatively, robotic- or computer-assisted systems use 3D planning based on the patient’s specific anatomy and can help optimize joint function.

Intraoperative pressure monitors and motion sensors help predict and guide knee kinematics. This technology enables the surgeon to accurately map out the surgery, reducing the risk of misalignment and short-term or long-term failure.

3D printing and custom implants

3D printing technology allows flexibility and options for producing sophisticated custom orthopedic implants.

“This facilitates implant availability and manufacture for routine primary surgeries but can be used to manufacture custom implants in difficult and revision procedures,” Dr. Khalily said.

Knee replacement implants are made with biocompatible materials such as titanium, cobalt chrome and ceramics. Custom or standard implants now can be produced with greater detail and ease versus traditional metallurgical techniques.

Additionally, the 3D internal structure and pore configuration of the printed implants can be optimized for enhanced biological osseointegration.

Smart implants and wearable technology

Smart implants are equipped with sensors that monitor knee function after surgery. These sensors gather real-time data that can be shared with the patient’s health care provider. Remote monitoring obviates the need for some in-person follow-up visits.

Data from the “smart knee” can help providers customize rehab protocols and might help predict any complications. The information gathered also can provide valuable data regarding load bearing, kinematics and range of motion.

Over time, surgeons can use the data to understand the postoperative fate of knee surgery.

Augmented reality in surgery

The newest area of interest in joint replacement surgery is the use of augmented reality. Augmented reality overlays digital information, such as the patient’s anatomy or implant positioning, onto the surgeon’s field of view in real-time.

Augmented reality is currently used in simulation and surgeon training. When partnered with image-guided or robotic technology, it has the potential to revolutionize the way surgery is performed.

According to Dr. Khalily, advances in surgical technology already in use and on the horizon — like augmented reality — will continue to improve a tried-and-true surgical procedure for knee pain caused by arthritis, helping improve the lives of patients in the process.