A recent study conducted by researchers from Kyushu University has provided evidence in favor of preserving a patient’s native alignment during knee replacement surgery, rather than aiming for a neutral alignment. Knee replacement surgery, also known as total knee arthroplasty, is recommended for individuals with severe damage to the knee due to injury or arthritis, to alleviate pain and improve mobility. The traditional approach of achieving a neutral alignment may not always replicate the patient’s original alignment, leading to debate within the orthopedic community on the best approach. The study, published in The Bone & Joint Journal, aimed to settle this debate and provide guidance on preoperative planning and execution of knee replacement surgery.
The research focuses on a classification system known as the Coronal Plane Alignment of the Knee (CPAK), which categorizes knee joint alignments based on two main characteristics. These characteristics include the hip-knee-ankle angle, which determines the positioning of the knees outward or inward, and the angle of the joint line, which refers to the alignment between the femur and tibia. By analyzing data from 231 patients who underwent knee replacement surgery at Kyushu University Hospital, the researchers sought to determine the impact of changes in CPAK classification on patient outcomes. Factors such as symptoms, overall satisfaction, activity levels, and quality of life were assessed through standardized scores derived from patient questionnaires.
The results of the study revealed that patients who experienced changes in knee alignment after surgery had significantly worse long-term outcomes. Specifically, patients whose joint line angle was tilted to the outside of the knee reported poorer outcomes postoperatively. These findings underscore the importance of replicating a patient’s native alignment during knee replacement surgery to ensure optimal recovery and a higher quality of life. By aiming to restore the patient’s inherent alignment, surgeons may be able to enhance postoperative outcomes and provide a more personalized approach to knee alignment.
Moving forward, the research team plans to incorporate the CPAK classification into preoperative planning, setting each patient’s native knee alignment as the surgical target. With the use of robot-assisted technology, total knee arthroplasty can be performed with high precision to accurately reproduce the preoperative plan. By improving the standard of knee replacement surgery through personalized alignment approaches, the researchers aim to enhance the postoperative lives of patients, promoting healthier and more active lifestyles. This prospective approach may lead to a new standard in orthopedic surgery and address the variability in patient outcomes following total knee arthroplasty.