Abstract
Introduction: Gender specific total knee prostheses have been developed and one expected outcome of a prosthesis that fit normal anatomy better would be the need for fewer soft-tissue releases at the time of implantation. The purpose of this study was to report any change in the frequency of soft-tissue maneuvers between a standard versus a gender based TKA design.
Methods: Using the same surgical technique, 568 consecutive primary cruciate retaining TKAs were performed by the author. Only female patients are reported. 258 received a Standard design and 160 received a Gender TKA design. Both groups were statistically evaluated for diagnosis, height, weight, body mass index (BMI), knee alignment, range of motion (ROM), total Knee Society Score (KSS), and the KSS pain component score.
Intra-operative parameters including all soft-tissue releases and component sizes were recorded.
Results: There was a significant decrease in lateral retinacular release utilization (p < 0.001) and overall soft-tissue releases (p < 0.002) when using the Gender TKA. There was also a significant shift in the size of femoral components used away from smaller Standard TKA femoral components. (p < 0.001). There was no change in the use of the polyethylene insert thickness (p = 0.368).
Discussion: Acceptance of femoral component design limitations may adversely affect the outcome of primary TKA. The use of a prosthesis that better reproduces female anatomy decreased the need for soft tissue ‘adjustments’. Additionally a larger size of femoral components was used. This requires less bone resection and may lead to better knee kinematics with a more normal posterior femoral offset. It is concluded that this design change improves operative technique of total knee replacement by requiring fewer releases in female patients.
Correspondence should be addressed to Diane Przepiorski at ISTA, PO Box 6564, Auburn, CA 95604, USA. Phone: +1 916-454-9884; Fax: +1 916-454-9882; E-mail: ista@pacbell.net