Introduction. We compared standard NexGen Cruciate substituting-flex prosthesis with gender-specific NexGen Cruciate substituting flex prosthesis in patients undergoing bilateral total knee arthroplasty with regard to Coverage of the bone by femoral component, Clinical outcome, Radiographic outcome, Survival and complication rates, with special emphasis on patellofemoral complications. Material & Methods. 30 female patients with osteo-arthritis of the knees with similar deformity and preoperative range of motion were randomized to have one knee replaced with a gender non-specific Nexgen Cruciate substituting (Zimmer) prosthesis and the other with Gender Cruciate substituting (Zimmer) prosthesis. Follow-up clinical evaluation was done at 6, and 12 months postoperatively and then at yearly interval using “Knee Society” Recommendations. Clinical assessment of the patellofemoral joint of the replaced knees was done with the help of “Hospital for Special Surgery” patellar scoring system. The overall patient satisfaction after surgery was evaluated with use of the British Orthopaedic Association patient satisfaction score. Results. The mean age was 63.8 years (range 49–76 years). 14 patients had standard NexGen Cruciate substituting-flex gender knee prosthesis on right side and 16 patients had on left side. On the other sides, standard NexGen Cruciate substituting-flex prosthesis implant was used. Preop Clinical findings were similar in both groups. The average Preop range of motion was identical in both the groups. The average follow up was 2.5 years (2–3.8 years). The mean post-operative Knee Society knee scores were 88,90,94, (70 to 100) and 87,92, 93 (70 to 100) points and the function scores were 83,85,88 (60 to 100) and 84.86.88 (60 to 100) points for the standard implants and the gender-specific designs, respectively at 6 months, 1 year and 2 year follow up. Mean improvement in patella score was 65, 71.1 and 73.3 points in Gender group at the end of 6 month, 1 yr and 2 yr respectively as compared to 65.6, 71.1 and 72.2 in Nexgen group. No patient had malpositioning of components or radiolucencies at the end of 2 year follow up. Mean improvement in BOA functional score was 20.6, 22.6 and 24.1 points in Gender group at the end of 6 months, 1 year and 2 year respectively as compared to 20.7, 21.8 and 23.2 in Nexgen group. In those with a standard prosthesis, the femoral component was closely matched in 30 knees, overhung in 17 and undercovered the bone in 13. In those with a gender-specific prosthesis, it was closely matched in 45 knees and undercovered the bone in 15. Conclusion. Although gender specific knee matched the femoral anatomy of Indian female knees better than the standard nexgen Knee, we found no significant differences between the two groups with regard to the clinical and radiological results, patient satisfaction or complication rate

Background. Improving quality and efficiency is a priority in health policy. Several studies have shown a correlation between high hospital volume and improved results of surgery. In Norway, orthopaedic surgeons operate a relatively low number of total knee replacements compared with other countries. The number of total knee replacements has, however, increased significantly over the past 10 years. Some studies have also shown an association between surgeon volume and outcomes after total knee arthroplasty (TKA). Purpose. We wanted to study a possible correlation between prosthesis survival and surgery volume of TKA, both with respect to hospital volume and surgeon volume. Materials and Methods. To examine the annual surgery volume per hospital we used registry data from the Norwegian Arthroplasty Register (NAR) for cemented TKA without patella component from 1994–2009. A questionnaire regarding surgeon volume in 2000 and 2009 was sent to all 58 operating hospitals in Norway, as this is not registered in the NAR. We received responses from 29 hospitals. Surgeon volume was defined by the percentage of surgeons at the hospital who operated 1–10 TKA over a year. Cox regression (without adjustment) was used to estimate proportions without revision and relative differences (RR). Analyses were also done for a subset of commonly used prostheses (AGC, LCS, LCS Complete, Duracon, NexGen, Profix), and for the prosthesis LCS and Profix separately. Results. Median annual hospital volume increased from 19 knees in 1995 to 83 in 2009. Prosthesis survival at 10 years was 92.5% (95% CI: 91.6–93.4) with 1–24 operations annually and 95.3% (93.7–96.8) with 100–149 operations. We found a lower risk of revision for hospitals with 25–49 (RR = 0.86, p = 0.06), 50–99 (RR = 0.81, p = 0.01, 100–149 (RR = 0.59, p<0.001 and 150 or more (RR = 0.48, p <.001) operations per year, compared to the hospitals with 1–24 operations. The analyses for subgroups of prosthesis brands provided similar results, except for the Profix prosthesis where there was no difference between hospital volumes. In 2000, 47% of the Norwegian hospitals had two thirds of the surgeons operating 1–10 TKA annually, but this was reduced to 24% in 2009. High annual surgeon volume gave the best results in our analyses. Conclusion. There has been an increase in the number of TKAs over time, in Norway as in other countries. Surgeon volume has also increased over time. Previously a high number of surgeons performed a low number of total knee arthroplasties, but this has been significantly reduced over the last 10 years. Survival curves from the NAR show a gradual improvement over time regarding the results of TKA. Our study indicated better results for TKA both at higher hospital volume and surgeon volume. Further analyses should investigate whether other factors may have an influence on this result