knee

The Zimmer Gender Solutions NexGen High-Flex Knee Implants compensate for the most important differences between women’s and men’s knees.

A growing body of research has led to breakthroughs in distinctive female and male diagnoses and treatments — for conditions ranging from heart disease to rheumatoid arthritis. The need to account for gender-specific solutions in orthopedics is apparent.

• Orthopedic surgeons have reported anatomical differences in women’s and men’s knees for years^1-8
• Orthopedic surgeons often have to consider intraoperative adjustments during knee surgery to accommodate women’s anatomical differences⁴
• Women account for nearly two-thirds of knee arthroplasties performed annually in the U.S^9,10
• Women are three times more likely than men to forego knee arthroplasty¹¹

NexGen High-Flex Implant Brochure

1. Hitt K, Shurman Jr II, Greene K, et al. Anthropometric measurements of the human knee: correlation to the sizing of current knee arthroplasty systems. J Bone Joint Surg Am. 2003;85:115-122.
2. Poilvache PL, Insall JN, Scuderi GR, Font-Rodriguez DE. Rotational landmarks and sizing of the distal femur in total knee arthroplasty. Clin Orthop Relat Res. 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):213-217.
5. Csintalan RP, Schulz MM, Woo J, McMahon PJ, Lee TQ. Gender differences in patellofemoral joint biomechanics. Clin Orthop Relat Res. 2002;402:260-269.
6. Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. I: Measurements of incongruence. Clin Orthop Relat Res. 1983;176:217-224.
7. Hsu RW, Himeno S, Coventry MB, Chao EY. Normal axial alignment of the lower extremity and load-bearing distribution at the knee. Clin Orthop Relat Res. 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. Am J Sports Med. 1992;20(2):208-211.
9. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for 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 Center for Health Statistics. 2003 National Hospital Discharge Survey, Advance Data No. 359. July 8, 2005; Table 10:16.
11. Hawker GA, Wright JG, Coyte PC, et al. Differences between men and women in the rate of use of hip and knee arthroplasty. N Engl J Med. 2000;342:1016-1022.

Pioneering research conducted by Zimmer has mapped the anatomical differences between female and male knees,^1,2 laying the foundation for the design and development of Gender Solutions High-Flex Femoral Implants.

• Three-dimensional CT data were collected and analyzed for more than 800 femurs and patellas
• Significant differences were identified between female and male knee anatomy
• Plotting M/L and A/P dimensions of the distal femur reveals 2 distinct populations: female and male

Implant designs that distinguish between female and male anatomical differences allow for improved implant fit and fewer intraoperative adjustments. Gender Solutions High-Flex Femoral Implants address the distinctive differences typically found in the female anatomy.

Gender Solutions High-Flex Femoral Implants address the distinctive anterior condyle differences by:

• Reducing the anterior flange thickness of the implant
• Recessing the patellar sulcus
• Retaining the clinically successful NexGen patellar articulation
• Avoiding overstuffing that may limit postoperative range of motion^3,4 that can occur when placing a traditional implant on a resected female knee

1. 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.
2. Data on file at Zimmer.
3. 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.
4. 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.