Objectives
Research suggests differences in coronal plane alignment of the knee (CPAK) classification between Asian and Western populations. This study aimed to determine the CPAK classification and to compare the sex and ethnic differences in arthritic knees in the Malaysian population.
Subjects and Methods
This retrospective cohort study included 250 arthritic patients (500 knees) scheduled for total knee arthroplasty and unicondylar knee arthroplasty between 2023 and 2024 at a tertiary hospital in Malaysia. The lateral distal femoral angle and medial proximal tibial angle were measured using digital long leg radiographs. A complete and independent set of measurements were performed by a radiologist to validate the collected data.
Results
In this study, the most common type of CPAK classification was Type I (45.2%), followed by types IV (22.4%) and V (9.6%) in the arthritic Malaysian population. CPAK type VIII was the rarest type, accounting for only 0.8% of cases. The most common CPAK classification among both sexes (male and female) and among the three ethnic groups of the Malaysian population (Malay, Chinese, and Indian) was also similar, with Type I being the most common, followed by Type IV and Type V.
Conclusion
Constitutional varus is more common in the Malaysian population than in their Western counterparts. Most Malaysian populations with arthritis are better suited to Kinematic Alignment total knee arthroplasty. Surgical outcomes can be optimized by understanding the typical CPAK distribution by tailoring surgical approaches such as alignment principles and ligament balancing techniques to better suit the inherent knee anatomy of Malaysian patients