Distal Femur and Proximal Tibia Morphometry in Women: Systematic Review and Meta-Analysis for Optimizing Precision in Arthroplasty and Orthopaedic Care

Morphometric differences between male and female knees play a crucial role in arthroplasty design, surgical planning, and functional outcomes. Understanding sex-based variations in distal femoral and proximal tibial anatomy is essential for improving implant fit and reducing postoperative complications. A systematic review and meta-analysis were conducted according to the PRISMA 2020 guidelines. PubMed, Embase, and Scopus were searched up to June 2025 for studies reporting sex-specific morphometric data of the distal femur and proximal tibia. Standardized mean differences (SMDs) were calculated for anteroposterior (AP), mediolateral (ML), and aspect ratio (AR = AP/ML) parameters using random-effects models. Heterogeneity was assessed using the I2 statistic, and publication bias with Egger’s test. Twenty-one studies encompassing 5,184 knees (2,889 females; 2,295 males) were included. Females had significantly smaller distal femoral and tibial dimensions across all measured parameters. Pooled SMDs showed reduced femoral AP (− 1.70; 95% CI − 2.23 to − 1.17) and ML (− 2.23; 95% CI − 2.47 to − 1.99) dimensions, with a lower femoral aspect ratio (− 0.46; 95% CI − 0.73 to − 0.20). Tibial AP (− 1.62; 95% CI − 1.83 to − 1.40) and ML (− 2.21; 95% CI − 2.56 to − 1.86) dimensions were also smaller in females, whereas tibial aspect ratio differences were nonsignificant (− 0.14; 95% CI − 0.35 to 0.07). Subgroup analyses by measurement modality and continent consistently confirmed these findings. No strong statistical evidence of publication bias was observed. Female knees exhibit significantly smaller distal femoral and proximal tibial dimensions, particularly in the mediolateral plane, with relatively lower femoral aspect ratios. These differences provide anatomical data that may inform implant design considerations, including sizing strategies and morphological conformity.