Native knee kinematics are reproduced during the golf swing after total knee arthroplasty apart from rotation: a case control study of hip and knee kinematics of patients returning to golf compared to match controls

Objectives Golf is a popular sport in older adults and this same population has an increasing prevalence of osteoarthritis affecting major joints such as the knee. To the authors knowledge the effect of Total Knee Arthroplasty (TKA) on the movements in the golf swing has not been extensively investigated despite the large prevalence of golfers who have undergone TKA. We aimed to determine lower limb joint kinematics during the golf swing and whether these are influenced following TKA. Methods A case-control study was undertaken with ten right handed golfers who had undergone TKA (cruciate retaining single radius implant) and five matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events. Results The left knee demonstrated large effect sizes for lower external rotation during take away, mid (p=0.01) and top of backswing in the TKA group. In contrast, the right knee demonstrated large effect sizes for lower external rotation in the TKA group during the downswing, contact and follow through phases. There were no differences in knee flexion/extension, ab/adduction, or JAV between the groups. Both hips demonstrated statistically significantly (p=0.02 for left and p=0.04 for right) lower flexion in the TKA group during the takeaway swing event, and lower internal rotation in the backswing and greater external rotation in the downswing of the right hip. Conclusion Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the back swing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee. Level of Evidence IV