“Is surgery more accurate if it is done with a robot?”
This is a question patients facing joint replacement often ask. Robotics and navigation can help improve surgical accuracy. They represent a meaningful advance, allowing surgeons to use objective measurements during surgery to execute their plans more precisely, in addition to relying on their clinical experience and judgment.
So what exactly are they trying to match more accurately? To understand this, we first need to look at the goals of joint replacement surgery.
■The goal of joint replacement: restoring length, offset and stability
Hip replacement surgery does not end with replacing a damaged joint with a prosthesis. Leg length must be matched, the joint structure must be restored so the surrounding muscles work properly, and the joint must remain stable during movement. The goals that represent this are the restoration of length, offset and stability.
Put simply, hip offset refers to the horizontal distance between the center of the hip joint and the axis of the femur (thigh bone).This distance relates to the length of the lever through which the surrounding muscles act. Even when leg length is well matched, an inappropriate offset can affect muscle function and joint stability. These factors must therefore be considered together.
■ Navigation helps verify; robotics helps execute
Robotics and navigation help surgeons achieve these goals, but in slightly different ways.
Navigation shows position, angle and changes in length numerically during surgery. It adds objective information to what surgeons previously judged by sight and touch. It allows surgeons to identify deviations from the preoperative plan and make adjustments before the procedure is completed.
This is an important advantage in joint replacement, where small differences matter, because some information that could once be confirmed only on postoperative images can now be reviewed during surgery. When measurement conditions and equipment accuracy are properly verified, navigation can serve as a valuable tool to support surgical decision-making.
Depending on the system, robotics uses these measurements and plans to help control the extent of bone resection or the movement of instruments. Its role is to help carry out the surgeon’s plan more consistently in the actual operation. Some functions also reduce deviation from the planned range and help preserve necessary bone and surrounding tissue, although the scope of support varies by device and surgical site.
In short, if navigation helps confirm the gap between the current state and the plan, robotics contributes to greater precision in executing the plan. The functions of the two technologies partly overlap, and in real surgery both are used together with the operating surgeon’s judgment.
■ Using the equipment is not the goal; it starts with sound preoperative planning
What matters is that using robotics and navigation cannot, and should not, become the purpose of surgery in itself. The purpose is to restore the joint function the patient needs. The value of the equipment lies in how much it helps achieve that goal.
This requires appropriate preoperative planning. Every patient differs in bone shape and size, joint deformity, leg length and muscle condition. These differences must be assessed through imaging, and surgeons must determine the appropriate prosthesis and its optimal placement to restore leg length and offset.
During surgery, they confirm whether that plan is actually being achieved. If navigation shows an unexpected change in length, the cause is examined and, if necessary, the prosthesis position or choice of instruments is adjusted. When robotics is used, the actual condition of the bone and soft tissue must still be assessed alongside execution of the plan.
The operating surgeon’s experience and surgical technique, as well as the characteristics of the prosthesis, also play an important role here. Knowing the measurements accurately must be followed by correcting any differences safely. Surgeons must achieve the desired length and offset while confirming that the implant is securely fixed and the joint moves well.
■ As surgical data accumulate, surgery itself improves
Another benefit of these technologies is that they generate data that can be used to evaluate and improve surgical procedures. Comparing the preoperative plan, intraoperative measurements and postoperative results shows at which stage differences arose. As such data accumulate, they help refine measurement methods and surgical planning and support medical teams in sharing experience and training.
Of course, accurate numbers on a screen do not guarantee pain relief, walking function or satisfaction. A patient’s recovery is shaped by many factors together, including the condition of muscles and tendons, other illnesses and rehabilitation. Turning the accuracy gained through technology into real recovery requires every stage of surgery to be closely connected.
The reason for using robotics and navigation is clear: to plan better before surgery, to identify differences more accurately during surgery and to correct what is needed with precision. Appropriate prosthesis selection, skilled surgical technique and postoperative evaluation are then added to this.
Together, these efforts aim to restore leg length, offset and stability more precisely, ultimately contributing to better surgical outcomes for patients.
That is the very purpose of using robotics and navigation.
■FAQ
Q1. Is hip surgery more accurate with a robot?
A1. Robotics and navigation can help improve accuracy by letting surgeons check conditions numerically during surgery and carry out the plan precisely. But using the equipment is not the goal in itself; the surgeon’s judgment, prosthesis selection and surgical technique all work together.
Q2. How do navigation and robotics differ?
A2. Navigation shows position, angle and changes in length numerically during surgery, giving the surgeon a chance to confirm and correct differences from the plan. Depending on the system, robotics controls the extent of bone resection or instrument movement to help execute the plan more consistently.
Q3. What exactly is being matched more accurately in hip replacement?
A3. The restoration of leg length, offset and stability. Offset is the horizontal distance from the center of the hip to the thigh bone; even with matched leg length, an inappropriate offset can affect muscle function and joint stability.
Q4. If the numbers on the screen are accurate, is a good outcome guaranteed?
A4. No. Pain, walking function and satisfaction depend on many factors, including the condition of muscles and tendons, other illnesses and rehabilitation. Every stage from preoperative planning to postoperative evaluation must be closely connected.
<By Dr. Song Sang-ho, Director of Wellton Hospital | Edited by Jang In-sun, Health Kyunghyang reporter>
