Coronal plane alignment of the knee (CPAK) classification and its impact on medial unicompartmental knee arthroplasty: exposing a unexpected external shift of limb mechanical axis in case of prearthritic constitutional valgus alignment: a retrospective radiographic study

This article examines the impact of prearthritic constitutional valgus alignment on medial unicompartmental knee arthroplasty (UKA). The study found that a small percentage of patients with isolated medial osteoarthritis (OA) treated with medial UKA had a valgus alignment. These patients experienced a shift in the limb's mechanical axis after surgery, potentially leading to the progression of OA in the lateral compartment. The study also analyzed the alignment of prosthetic components and found specific angles for the tibial and femoral components. The study suggests that patients with valgus alignment may face challenges in achieving proper ligament balance after surgery and may be at a higher risk of OA progression in the lateral compartment. Further research is needed to confirm these findings and establish clinical correlations. [Extracted from the article]