Analysis of Proximal Tibial Resection Surface Dimention with Korean Total Knee Arthroplasty Specimens

ABSTRACT

In shape and dimensions, the tibial plateaus are asymmetric with the larger medial tibial plateau and both have a posterior inclination with respect to the shaft of the tibia. Maximizing tibial coverage is an impotant consideration in total knee arthroplasty to provide stahility and load transfer and to improve long-term survival rate of the implants. Most tihial tray designs are symmetric, but several asymmetric designs are available. We evaluated the proximal tibial resection surface during total knee aithroplasty to delineate the tibial plateaus in korean. After tihial bone cut during 100 TKA procedures, the outline of tibial resection suiface was traced and rotational axis of true tibial component was marked intraoperatively. A line was drawn at the maximal anteroposterior (AP) diameter of lateral tibial condyle with parallel to rotational axis of component, and then a transverse axis was drawn at the midpoint of maximal AP diameter of 1ateral tibial condyle. Anteroposterior 10, 20, 30., 40% and midpoint from the media1 and lateral peripheries were calculated manually. The average AP medial 10, 20, 30 and 40% dimensions were 34.7, 43.8, 48.0 and 43.2mm, respectively. The average AP lateral 10, 20, 30 and 40% dimensions were 30.2, 38.4, 42.0 and 40.9mm, respectively. The ratio of medial/lateral AP dimensions 10, 20, 30 and 40% from periphery were 116.9, 114.7, 114.5 and 106.4%, respectively. From these data, we know the asymmetry of the proxirnal tibia1 plateaus in korean. We hope that rnore data will be ohtained in multicenter studies and it will help us to select tibia1 tray and to design the tibial component in korean. But, more accurate standard measures will he need to minimize an error of measurements.