Robotic Partial Knee Replacement

What Are Partial Knee Replacement (UKA) and Robotic Surgery?

Partial Knee Replacement (Unicompartmental Knee Arthroplasty – UKA): The knee joint has three main compartments (medial, lateral, and patellofemoral). In UKA surgery, the damaged joint surfaces of only a single compartment affected by osteoarthritis are removed and replaced with smaller metal and polyethylene prosthetic components. The healthy cartilage and bone tissue in the knee’s other two compartments, along with the anterior and posterior cruciate ligaments (ACL/PCL), are preserved.

Robotic Partial Knee Replacement: This refers to performing the surgery with the assistance of a robotic system under the surgeon’s control. Robotic technology helps the surgeon create a precise plan on a 3D model of the patient’s knee before surgery, and helps carry out bone preparation (cutting or shaping) and placement of the prosthetic components during surgery in line with this plan, with millimetric accuracy. The goal is to ensure a perfect fit of the small prosthetic components to the knee, preserve natural knee mechanics, and extend the lifespan of the prosthesis.

Why Is Precision Important in Robotic Partial Knee Replacement? What Are the Advantages?

Precision in partial knee replacement surgery can be even more critical than in total knee replacement. This is because the prosthesis must work in harmony with the patient’s own healthy anatomy (the other compartments, the ligaments). The potential advantages of robotic surgery in this area are as follows:

• Millimetric Implant Placement: Robotic systems allow the small prosthetic components to be placed extremely precisely in the patient’s anatomy, at the planned angle and depth. This ensures the ideal contact and stability of the prosthesis with the bone.
• Optimal Alignment: Correctly adjusting the leg alignment (axis) during surgery is very important for the lifespan and function of the prosthesis. Robotic guidance can help achieve this alignment more accurately and reproducibly.
• Maximum Bone Preservation: Robotic systems (usually using a precise burr/mill) remove only as much bone as needed for the prosthesis, staying within the planned boundaries. This ensures maximum preservation of the patient’s own healthy bone stock.
• Function of the Preserved Ligaments: Correct placement of the prosthesis helps the tension and function of the preserved anterior and posterior cruciate ligaments continue as close as possible to their natural state.
• Potentially Better Outcomes: It is thought that the high precision achieved with robotic surgery may lead to better functional outcomes, a more natural knee feel, and potentially a longer prosthesis lifespan compared to conventional partial knee replacement. The goal is to reduce revision (repeat surgery) rates for partial knee replacements, although long-term data on this subject continues to accumulate.

How Is Robotic Partial Knee Replacement Surgery Performed?

The steps of robotic partial knee replacement surgery are generally as follows:

1. 3D Modeling and Planning: A three-dimensional digital model is created using the patient’s knee data, obtained either from preoperative CT/MRI or with a special camera system during surgery. The surgeon uses this model to identify the damaged compartment, select the most appropriate prosthesis size, and plan the boundaries of bone preparation and the ideal position of the prosthesis.
2. Registration: At the start of surgery, the virtual plan is matched with the patient’s actual knee anatomy using trackers placed on the knee.
3. Robot-Assisted Bone Preparation: Using a special burr or cutting instrument precisely guided by the robotic arm, the surgeon removes only the damaged bone and cartilage within the planned area. The robotic system prevents the surgeon from going beyond the planned boundaries.
4. Trial and Prosthesis Placement: After the bone surfaces are prepared, trial prostheses are inserted, and fit and ligament balance are checked. The permanent prosthetic components (femoral and tibial components) are then placed and fixed.
5. Closure: The wound is closed according to standard surgical technique.

It should be remembered that the robot is merely an assistant that carries out the surgeon’s instructions and increases precision; all decisions and control remain with the surgeon.

Who Is a Suitable Candidate for Robotic Partial Knee Replacement? (Correct Patient Selection)

Correct patient selection is extremely critical for the success of partial knee replacement. Robotic technology does not change this selection process—it only makes the procedure more precise in the selected patient. Suitable candidates generally have the following characteristics:

• Single-Compartment Osteoarthritis: The osteoarthritis must strictly be limited to just one part of the knee (medial, lateral, or rarely patellofemoral), with the other compartments remaining healthy.
• Intact Ligaments: In particular, the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) must be completely intact and functional. There should also be no significant laxity in the collateral ligaments.
• Limited Deformity: There should not be an advanced degree of bow-leg (“O-leg”) or knock-knee (“X-leg”) deformity. Mild to moderate, correctable deformities are acceptable.
• Good Range of Motion: Preoperative knee range of motion must be adequate (particularly full extension and sufficient flexion).
• Absence of Inflammatory Rheumatic Disease: Conditions such as rheumatoid arthritis are generally not suitable for partial knee replacement.
• Not Being Significantly Overweight: Obesity can negatively affect the success and lifespan of a partial knee replacement.
• Realistic Expectations and Motivation: The patient must understand the benefits and limitations of the surgery and be willing to actively participate in the rehabilitation process.

Rather than age alone being a determining factor, the patient’s activity level and meeting the above criteria are more important.

Comparison of Robotic UKA, Conventional UKA, and Total Knee Replacement (TKA)

• Robotic UKA vs. Conventional UKA: Robotic surgery aims to offer greater and more reproducible precision in bone preparation and implant placement. This may potentially translate into better fit, alignment, and lower revision rates in the long term. However, conventional UKA performed by an experienced surgeon can also produce successful results.
• UKA (Robotic or Conventional) vs. TKA:
  
  • Advantages (UKA): Smaller incision, less bone removal, preservation of intact ligaments, generally faster recovery, less postoperative pain, a more “natural” knee feel, potentially better range of motion.
  • Disadvantages/Limitations (UKA): Requires much stricter patient selection, is technically more demanding, may require conversion to total knee replacement if osteoarthritis develops in the other compartments later, and has historically shown earlier revision (repeat surgery) rates compared to TKA (robotic surgery aims to reduce this rate).
  • Advantages (TKA): Can be applied to a broader group of patients, is more tolerant of alignment problems and ligament imbalances, and treats all joint surfaces.
  • Disadvantages (TKA): Larger surgery, greater bone loss, sacrifice of the cruciate ligaments, potentially a less natural knee feel, and generally a longer recovery period.

Risks and Recovery Process

• Risks: The general risks of partial knee replacement surgery are similar to those of total knee replacement (infection, blood clots-DVT/PE, stiffness, nerve damage, etc.). Risks specific to UKA include early loosening of the prosthesis and the development of osteoarthritis in the other parts of the knee in later years, which may require conversion to total knee replacement. Additional risks specific to robotic surgery (pin site issues, etc.) are very low. The risk of revision has the potential to decrease with the precision of robotic surgery.
• Recovery Process: The recovery process after robotic or conventional partial knee replacement is generally markedly faster than after total knee replacement:
  
  • Hospital stay is shorter (sometimes just one night, or same-day discharge in suitable patients).
  • Postoperative pain is generally less.
  • Earlier full weight-bearing walking is possible (the need for crutches is generally shorter).
  • Physical therapy is still very important, but the program can progress more quickly.
  • Return to normal daily activities and work is generally earlier (within a few weeks).
  • Return to lower-impact sports can be earlier.

Robotic Partial Knee Replacement in Ankara and Prof. Dr. Murat Bozkurt’s Approach

Robotic partial knee replacement is an important advanced technology application in joint-preserving surgery, offered in Ankara to an appropriate group of patients. The success of this surgery depends, above all, on correct and meticulous patient selection.

When evaluating patients considering partial knee replacement in Ankara, Prof. Dr. Murat Bozkurt focuses on the following points:

• Comprehensive Evaluation and Meticulous Patient Selection: He determines whether a patient is strictly suitable for partial knee replacement based on the patient’s complaints, expectations, detailed physical examination findings, and imaging results (particularly MRI and weight-bearing radiographs). He knows that performing a partial replacement on an unsuitable patient will result in failure.
• Using the Precision Advantage of Robotic Technology: If the patient is a suitable candidate for partial knee replacement, he may aim to use robotic surgical technology to increase the precision of the surgery, ensure a perfect fit of the prosthesis, and achieve a potentially longer-lasting, more functional result. (Prof. Dr. Bozkurt’s use of this technology and his experience with it should be highlighted here.)
• Priority of Surgeon Experience: He knows that the robotic system is a tool, and that what truly matters is the surgeon’s knowledge and experience regarding partial knee replacement and their ability to select the right patients, and he informs his patients accordingly.
• Discussion of Alternatives: In cases where partial replacement is not suitable, or based on the patient’s preference, he also discusses other treatment options (osteotomy, total knee replacement, conservative treatments) with the patient in detail.

While offering the most modern and evidence-based treatment options to patients with knee osteoarthritis in Ankara, Prof. Dr. Bozkurt always aims to identify the method best suited to the patient’s individual situation and most likely to produce a successful outcome.

Robotic partial knee replacement is a joint-preserving, advanced technology surgical method that can provide excellent results in the treatment of knee osteoarthritis in properly selected patients. While it offers advantages such as faster recovery and a more natural knee feel, its success largely depends on correct patient selection and the surgeon’s experience. If you are considering this treatment option in Ankara, you can consult Prof. Dr. Murat Bozkurt to evaluate its suitability for you.

For detailed information and appointments, you can contact Prof. Dr. Murat Bozkurt at 0312 502 70 74.