title: [Medial anterior flange overhang related to the prosthesis selection determined by femoral sizer in total knee arthroplasty].
abstract: Objective:To evaluate the medial anterior flange overhang related to the femoral prosthesis size determined by femoral sizer in total knee arthroplasty.Methods:Sixty one cases of varus knee osteoarthritis (61 knees) were analyzed from January 2014 to January 2015, 14 males and 47 females, aged (66.8±6.8) year old. 3D models of distal femur were established by Mimics, total knee arthroplasty surgeries were simulated and the medial and lateral femoral condylar anteroposterior diameter were measured. According to the AP diameter of lateral femoral condyle (lateral condyle group) and femoral sizer (sizer group), different size of the PFC Sigma femoral prosthesis models were imported to mimics, and the coverage of medial anterior femoral flange were compared.Results:The AP diameter of lateral femoral condyle[(55.76±3.64) mm]was significantly less than the sizer group[(57.02±3.59) mm],P<0.05. The distal femur aspect ratio for male (1.2 %±0.1%) and female (1.2%±0.1%) has no statistically difference (P>0.05). Femoral prosthesis sizes, the uncoverage diameter of the anterior chamfer line, midpoint of the flange in the sizer group were significantly larger than the lateral condyle group (P<0.05). The femoral size, overhang ratio of anterior chamfer line and midpoint of the flange in male were significantly larger than females (P<0.05).Conclusion:The AP diameter determined by femoral sizer instrument had a tendency to larger prosthesis, and the risks of medial femoral anterior flange overhang increased. Medial anterior flange overhang in male was significantly less than female, but the difference had no correlation to the distal femur asepect ratio.
authors.affiliation: Department of Joint Surgery, Tianjin People's Hospital, Tianjin 300191, China.
authors.forename: Z H
authors.initials: ZH
authors.lastname: Sun
authors.forename: N
authors.initials: N
authors.lastname: Li
authors.forename: J Y
authors.initials: JY
authors.lastname: Xin
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: Z S
authors.initials: ZS
authors.lastname: Ren
authors.forename: H J
authors.initials: HJ
authors.lastname: Sun
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D004838:Epiphyses; D005260:Female; D005269:Femur; D006801:Humans; D007717:Knee; D007719:Knee Joint; D007720:Knee Prosthesis; D008297:Male; D020370:Osteoarthritis, Knee