Purpose of the study: It has been demonstrated that the anatomy of the distal femur differs by gender. The ratio of the mediolateral/anteroposterior distance, the shape of the distal femur, and the orientation of the trochlea differ between males and females. To adapt to these differences, prostheses specifically designed for female patients (TKAgender) were developed. The purpose of our study was to compare the first objective and subjective outcomes with these prostheses.

Material and methods: Thirty women who underwent bilateral surgery within a six month interval for degenerative joint disease of the knee between March 2006 and March 2008 were included in a comparative prospective study. The side receiving the gender implant was determined at random. Operative and postoperative protocols were the same excepting the femoral implant. Patients were not informed of which knee had received the gender prosthesis. Mean age in this series was 67 years and mean BMI 26. All implants were cemented. At minimum one year follow-up, objective and subjective analysis included specific questions concerning preference and quality of life presented by an independent observer.

Results: The Knee Society clinical scores were comparable in the two groups, as were the results for the different items of the KOOS score. For preferences: the patients preferred the gender knee in 75% of the cases (p< 0.01), they reported less noise or cracking sounds in the anterior part of the knee for 68% (p=0.03) and had the impression that the knee recovered faster in 64% (p=0.04).

Discussion: To our knowledge, this is the first report of results concerning implants specifically designed for female patients. At short-term, the only difference in the patients’ preference was a subjective feeling of less impairment for the patellar track. It will be interesting to follow these patients to assess the long-term impact on the patellofemoral articulation.

Introduction: Women have gender specific shape of the distal femur. To fit these gender characteristics, gender specific femoral implants were developed for total knee arthroplasty (TKA). We aimed to compare

objective and subjective functional improvement;

Materials and Methods: 30 women (60 knees) operated on successively (6 months in between) for a bilateral TKA between March 2006 and March 2008 by the same surgeon were included in this prospective study. The same surgical protocol and the same post-operative management protocol were applied for both sides. Mean age was 67±3 and mean BMI 26±4 Kg/m². At a minimum follow-up of one year, evaluation objective and subjective functional improvement, patient satisfaction and preference and cost-utility analysis were performed double blind.

Results: Knee Society knee score and Knee Osteoarthritis Outcome Score (KOOS) improvements were comparable in both groups. However, 75% of the women preferred their gender TKA (p< 0.001). 68% of the women described less crepitus or anterior knee bothering after gender TKA (p=0.003) and 64% had faster recovery with the gender implant (p< 0.001). The cost-utility analysis was favorable for the gender knee.

Discussion: No objective or subjective superiority in terms of functional improvement was shown with gender specific implants at this short-term follow-up. However significant differences in terms of patient satisfaction and preference and a favorable cost-utility analysis were observed. These results should now be confirmed at longer-follow-up. Despite comparative functional improvement, patient satisfaction and preference were higher for the side implanted with a gender specific TKA in this prospective comparative study.