Study Highlights Best Practices in Total Knee Replacement Surgery - Video

In an effort to understand which knee replacement surgery approach is better, researchers from Kyushu University collected convincing evidence in favor of preserving the patient’s native alignment. The study was published in The Bone & Joint Journal.

Neutral alignment is not always the patient’s original alignment and there is some debate within the orthopedic community on whether restoring the patient’s original alignment can lead to better patient-reported outcomes. In the present study, researchers have attempted to settle this debate and create a comprehensive guide on preoperative planning and execution of knee replacement surgery.

This study is mostly centered around a classification system called the Coronal Plane Alignment of the Knee (CPAK). It categorizes the possible alignments of the knee joint based on two main characteristics that is the hip-knee-ankle angle and angle of the joint line.

The research team sought to determine whether changes in the Coronal Plane Alignment of the Knee categorization before and after knee replacement surgery were associated with notable differences in outcomes. To this end, they collected data from 231 patients who received knee replacement surgery for osteoarthritis at Kyushu University Hospital between 2013 and 2019. Using X-ray images, the team determined the Coronal Plane Alignment of the Knee classification and alignment variables of the patients before and after surgery. They also sent a questionnaire to the patients, from which they derived a series of standardized scores related to symptoms, overall satisfaction, activity levels, and quality of life after the operation.

Researchers revealed that patients who underwent changes in knee alignment after knee replacement surgery, as determined using the Coronal Plane Alignment of the Knee classification, had significantly worse long-term outcomes. Interestingly, they also found that patients whose joint line angle was tilted to the outside of their knee after surgery reported overall worse outcomes as well. This study demonstrates that precisely replicating a patient’s native alignment during surgery is crucial for ensuring optimal recovery and a higher quality of life.

Reference: Konishi T, Hamai S, Tsushima H, et al. Pre- and postoperative Coronal Plane Alignment of the Knee classification and its impact on clinical outcomes in total knee arthroplasty. Bone Joint J. 2024;106-B(10):1059-1066. doi:10.1302/0301-620X.106B10.BJJ-2023-1425.R1