Vol.:(0123456789) 1 3 Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-017-4724-2 KNEE Tibial shaft anatomy difers between Caucasians and East Asian individuals Hongyi Shao 1  · Chilung Chen 2  · Daniel Scholl 3  · Ahmad Faizan 3  · Antonia F. Chen 4   Received: 24 March 2017 / Accepted: 15 September 2017 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017 distance between the femoral shaft centre and Whiteside’s line was lower, although not signifcantly diferent (Asians 1.9 ± 1.0 mm, Caucasians 2.2 ± 1.1 mm, n.s.). However, there were no diferences in the AP dimension for the femur or tibia comparing Asians to Caucasians in both tibial side (Asians 10.6 ± 3.3 mm vs. Caucasians 10.9 ± 4.0 mm) and femoral side (Asians 18.1 ± 1.7 mm vs. Caucasians 17.5 ± 1.6 mm). Conclusion East Asian individuals have more ofset in the ML dimension for the tibia. This fnding is clinical relevant, as this dimensional diference should be taken into consid- eration when designing primary and revision TKA stemmed tibial implants for East Asian individuals. Level of evidence Case–control study, Level III. Keywords Tibia · Femur · Shaft · Total knee arthroplasty · Caucasian · East Asian Introduction The incidence of revision total knee arthroplasty (TKA) has increased over the past decade, and it will continue to increase during the next 20 years [21]. To provide adequate fxation and stability in total knee revisions (TKR), compo- nents with stem extensions may be needed, especially when there is extensive bone loss [9] or when condylar constrained prostheses are used [23]. Fleischman et al. [14] reported that the lack of intramedullary canal fll from cementless stemmed components was the strongest predict of failure in revision TKA. Intramedullary axes can provide more precise anatomic landmarks compared to other methods, as the fbular axis was not a reliable landmark for deter- mining the tibial mechanical axis [20]. However, tibial and femoral shaft axes may not always match the centre of the Abstract Purpose The orientation and distance from the shaft of the femur and tibia to the articular surface centre is important for performing total knee arthroplasty (TKA) with cement- less stems. It is important to understand anatomic diferences between races to match the tibial and femoral shaft axis to the knee articular surface. Thus, the purpose of this study was to compare knee morphology between Caucasian and East Asian individuals to determine the optimal placement of tibial and femoral stems. Methods A retrospective study was conducted on a matched cohort of 50 East Asians (21F, 29M) and 50 Cauca- sians (21F, 29M) by age and gender. CT scans were obtained in healthy volunteers using < 2-mm slices. The distance from the proximal tibial diaphysis axis to the tibial plateau centre and the distance from the distal femoral diaphysis axis to the centre of distal femoral articular surface were measured separately. Tibial measurements were taken using Akagi’s anteroposterior (AP) axis and the widest mediolat- eral (ML) diameter, and femoral measurements were based on Whiteside’s line and the surgical epicondylar axis. Results The ML distance between the tibial shaft cen- tre and Akagi’s line was signifcantly higher for Asians (9.9 ± 2.7 mm, Caucasians 7.7 ± 3.1 mm, p < 0.001). The * Antonia F. Chen antonia.chen@rothmaninstitute.com 1 Department of Orthopaedic Surgery, Beijing Jishuitan Hospital, Beijing, China 2 Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan 3 Stryker, Mahwah, NJ, USA 4 Rothman Institute, Thomas Jeferson University Hospital, 925 Chestnut Street, 5th Floor, Philadelphia, PA 19107, USA