Clinical relevance Gender analysis of the anterior femoral condyle geometry of the knee Pingyue Li a,b , Tsung-Yuan Tsai a , Jing-Sheng Li a , Shaobai Wang a , Yu Zhang b , Young-Min Kwon a , Harry E. Rubash a , Guoan Li a, ⁎ a Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA b Department of Orthopaedic Surgery, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, Guangdong 510010, China abstract article info Article history: Received 23 May 2013 Received in revised form 12 November 2013 Accepted 18 December 2013 Keywords: Anterior femoral condyle TKA Gender-specific knee Background: No study has used 3-D anatomic knee models to investigate the gender differences in anterior fem- oral condyles. Therefore, this study aims to determine the morphologic differences between genders in anterior femoral condyles of the knees using 3-D anatomic knee models. Methods: Ninety-six male and sixty-five female 3D anatomic knee models were used to measure lateral and me- dial anterior condyle heights, anterior trochlear groove heights, and anterior condyle width, which were normal- ized by the anterior–posterior and medial–lateral dimensions of the knee, respectively. The shape of anterior condyle groove was also analyzed. Results: The mean lateral anterior condyle height, medial anterior condyle height and anterior condyle width of females were 6.6 ± 1.8 mm, 2.0 ± 2.3 mm, and 44.7 ± 4.2 mm, respectively. These data were significantly smaller (p b 0.05) than those of males (7.7 ± 1.8 mm, 2.9 ± 2.0 mm and 50.0 ± 3.4 mm). However, after nor- malizing by the femur size, the aspect ratios had no gender differences. Both the ranges of lateral and medial con- dyle of females were significantly smaller than those of males, and the geometry curve of anterior condyle was different between genders. Conclusion: Although the gender differences in anterior femoral condyle sizes no longer existed after normalization with the femur size, the shape and the peak position of anterior condyle groove still have gender differences. The data may have important implications on the current debate of gender-specific TKAs. Clinical relevance: This study provides a better understanding of gender differences in anterior femoral condyle geometry. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Anatomic variations between the knees of men and women have been reported in many studies [1–3]. Some studies reported that the fe- male knee has a less pronounced anterior femoral condyle height than the male knee [4,5], leading to the development of gender-specific knee implant designs that have a thinner and narrower anterior flange to avoid the patellofemoral joint being overstuffed in female knees [6]. However, others argued whether there is a gender difference in ante- rior femoral condyles of the knee. Fehring et al. [7] analyzed magnetic resonance images of the knee and found that there is no significant dif- ference between men and women when the anterior condyle heights were normalized by the femoral medial–lateral dimensions. Brattstroem [8] performed a radiographic-anatomic study and found that women had lower lateral and medial anterior condyles than men, but that was attributed to the smaller size of the women. A gender-specific anterior flange design for femur component was therefore questioned in recent literature [7,9,10]. Merchant et al. reviewed the evidence presented to support that females have less prominence of the anterior medial and lateral condyles and concluded that these differences do not exist [9]. Greene et al. also concluded that there was little evidence to support that gender-specific changes in TKA components lead to better outcomes and suggested further research to assess the gender-specific designs [10]. A literature review indicated that most recent studies used plane ra- diographic or MRI images to study the gender differences of anterior fem- oral condyle morphology [4,7,8]. No study has used 3-D anatomic knee models to investigate the gender differences in anterior femoral condyles. Therefore, the aim of this study is to determine the gender morpho- logic difference in anterior femoral condyles of the knees using 3-D anatomic knee models. The heights of the lateral anterior femoral condyle, medial anterior femoral condyle, anterior trochlear groove, and the width of anterior condyle were measured in both male and female knee models. These parameters were then normalized by the anterior–posterior and medial–lateral dimensions of the knee to calculate the aspect ratios of the anterior condyle and trochlear groove heights as well as the anterior condyle width. We hypothe- size that there is a gender difference in anterior femoral condyle morphology between the male and female knees. The Knee 21 (2014) 529–533 ⁎ Corresponding author at: Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, 55 Fruit St., GRJ-1215, Boston, MA 02114, USA. Tel.: +1 617 726 6472; fax: +1 617 724 4392. E-mail address: gli1@partners.org (G. Li). 0968-0160/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.knee.2013.12.001 Contents lists available at ScienceDirect The Knee