Zimmer® Gender Solutions™ NexGen® High-Flex Knee

Modified ML/AP Aspect Ratio

CT data documents distinctive shape differences in female and male distal femurs.12,13 Female femurs are:

  • More trapezoidal-shaped.

  • Narrower in the M/L dimension when compared to a male femur of the same A/P dimension
Modified ML/AP Aspect Ratio

When a traditional implant is placed onto a resected female knee:

  • The implant may overhang the bone at the distal, anterior, and posterior M/L interfaces, which may lead to soft-tissue irritation and affect soft-tissue
    balancing.1,3,4
  • The surgeon may be faced with intraoperative adjustments to compensate for the overhang.

Gender Solutions High-Flex Femoral Implants have been narrowed mediolaterally.

This allows surgeons to address the female population with unprecedented accuracy.
Modified ML/AP

Related Articles

Zimmer Gender Solutions NexGen High-Flex Knee Overview
Two Distinct Populations:  Women and Men
Anterior Flange Thickness
Increased Trochlear Groove Angle
Femoral Mapping—Applying the Science

References

  1. Hitt K, Shurman IIJ, Greene K, et al. Anthropometric measurements of the human knee: correlation to the sizing of current knee arthroplasty systems. J Bone Joint Surg. 2003;85:155-122.
  2. Poilvache PL, Insall JN, Scuderi GR, Font-Rodriguez DE. Rotational landmarks and sizing of the distal femur in total knee arthroplasty, Clin Orthop. 1996;331:35-46.
  3. Vaidya SV, Ranawat CS, Aroojis A, Laud NS. Anthropometric measurements to design total knee prostheses for the Indian population. J Arthroplasty. 2000;15(1):79-85.
  4. Chin KR, Dalury DF, Zurakowski D, Scott RD. Intraoperative measurements of male and female distal femurs during primary total knee arthroplasty. J Knee Surg. 2002;15(4):213-214.
  5. Csintalan RP, Schulz MM, Woo J, McMahon PJ, Lee TQ, Gender Differences in Patellofemoral Joint Biomechanics, Clin Orthop. September, 2002; 402 :260-269.
  6. Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. I: Measurements of incongruence. Clin Orthop. 1983;176:217-224.
  7. Hsu RWW, Himeno S, Coventry MB, Chao EYS. Normal axial alignment of the lower extremity and load bearing distribution at the knee, Clin Orthop . 1990;255:215-227.
  8. Woodland LH, Francis RS. Parameters and comparisons of the quadriceps angle of college-aged men and women in the supine and standing positions. American Journal of Sports Medicine. 1992;20:208-211.
  9. U.S.Department of Health and Human Services, Centers for Disease Control and Prevention, National Centerfor Health Statistics. 2003 National Hospital Discharge Survey, Advance Data No. 359. July 8, 2005; Table 8:14.
  10. U.S.Department of Health and Human Services, Centers for Disease Control and Prevention, National Centerfor Health Statistics. 2003 National Hospital Discharge Survey, Advance Data No. 359. July 8, 2005; Table 10:16.
  11. Hawker G, Wright J, Coyte P, et al., Differences between men and women in the rate of use of hip and knee arthroplasty, The New England Journal of Medicine. 342:1016-1022, 2000.
  12. Mahfouz M, Booth R Jr, Argenson, J, Merkl, BC, Abdel Fatah EE, Kuhn MJ. Analysis of variation of adult femora using sex specific statistical atlases. Presented at: Computer Methods in Biomechanics and Biomedical Engineering Conference; 2006.
  13. Data on file at Zimmer
  14. Scott NW. Pearls on avoidance and treatment of intraoperative and postoperative complications – exposure of the stiff knee. Presented at: American Association of Hip and Knee Surgeons, Knee Society Specialty Day; March 25, 2006.
  15. Bengs BC, Scott RD. The effect of patellar thickness on intraoperative knee flexion and patellar tracking in total knee arthroplasty. J Arthroplasty. 2006;21(5):650-655.