In Vivo Sagittal Plane Kinematic Analysis Of Asian Knees After Oxford Unicompartmental Knee Arthroplasty (UKA) And Its Relation With Functional Outcome And Sex Of Patient

Introduction:
We analysed in vivo sagittal plane kinematics of 20 knees after implantation of Oxford mobile bearing Unicompartmental knee. It is proposed that UKA mimics normal knee kinematics as the ligaments are not sacrificed in this surgery. We hypothesise that there is a difference in kinematics among patients with different sex and functional outcomes.
Objectives:
To correlate in vivo Knee Kinematics relationship with Functional outcome and sex of patient after unicompartmental knee arthroplasty
Methods:
In vivo sagittal plane kinematics of 20 knees was analysed using the MATLAB software after performing step up and deep knee bend exercise under fluoroscopy. The patellar tendon angle (PTA) was plotted at varying knee flexion angles (KFA). Patients were divided into 2 groups: one with Oxford Knee Score (OKS) more than 40 and the other with less than 40. Another 2 groups based on sex were made(male and female). Using p value less than 0.05
Results:
The in vivo sagittal plane kinematics after UKA mimicked the normal knees. Mann Whitney analysis was performed to calculate the difference between the groups. There was significant difference (p value=0.0028) between male and female groups. The difference between the groups based on OKS was also significant (p value = 0.007).
Conclusions:
Kinematics after UKA mimics normal knee and there is significant difference in the knee kinematics in patients with superior functional outcomes when compared with those with inferior functional outcomes when PTA was plotted at varying KFA. Also there is significant difference between the kinematics after UKA between males and females.