Femoral Prosthesis Design Oriented Measurement Of Adult Proximal Femur Parameters In Northeast China

Objective：To measure proximal femoral parameters of the adults inNortheast China for the preoperative planning prior to the total hiparthroplasty（THA）. To provide data support for the design of hipprosthesis which could be more appropriate for Chinese adults.Methods：we selected100normal adult bi-hip radiographs randomlyfrom China-Japan Union Hospital which included50males and50females and determined these following parameters: the diameter offemoral head; neck-shaft angle; neck length; femoral offset; the heightfrom the center of femoral head to the tip of greater trochanter; ridian offemoral calcar; width of the medullary cavity at less trochanter (Dt) andthat of the upper surface at20mm(Dt+20), and10mm(Dt+10) and20mm(Dt-20) lower surface; the endosteal width at the isthmus (Di); thedistance from the level of the isthmus to the less trochanter(H). Andbased on these results above we calculated following parameters: canalflare index (CFI); metaphyseal canal flare index(MCFI1);MCFI2(Dt+10/Dt-20). All these parameters were revised and showed as theform of x±SD. SPSS13.0was used for statistic analysis. Independentt-test was applied to analyze the difference between male and female andpaired t-test to analyze the difference between left and right sides.Correlation analysis was peformed between every two parameters. andwe compared the results with some other domestic and foreign researches.Results: The diameter of femoral head was48.64±4.09mm; neck-shaftangle was126.4±4.6°; neck length was51.37±5.69mm; femoral offsetwas41.29±5.73mm; the height from the center of femoral head to the tipof greater trochanter was7.86±4.51mm; ridian of femoral calcar was0.49±0.17rad; width of the medullary cavity at less trochanter (Dt) was27.22±3.53mm and that of the upper surface at20mm(Dt+20), and10mm(Dt+10) and20mm(Dt-20) lower surface was43.83±4.90mm,33.69±4.12mm and19.58±2.61mm; endosteal width of the isthmus (Di) was10.92±1.60mm; the distance from the level of the isthmus to the lesstrochanter(H) was98.97±14.82mm. canal flare index (CFI) was4.10±0.73; metaphyseal canal flare index(MCFI1) was2.26±0.21mm;MCFI1(Dt+20/Dt-20) was1.73±0.14. No significant difference was foundbetween left and right sides (p>0.05); Most of the parameters hadstatistically significant differences(p<0.05) between men and womenexcept the neck-shaft angle, the relationship between the center offemoral head and the tip of greater trochanter, the ridian of cortex in thearea of femoral calcar and CFI. The proportion of CFI which was biggerthan4.7in women (24%)was bigger than that in men (14%). Statisticallysignificant difference(p<0.05) was found in five parameters (offset, Dt-20,Di, MCFI1, CFI)between different age groups. Compared with somedomestic and foreign research results, several parameters were significantly different (p<0.05).Conclusion:1. Many of the parameters of adult proximal femur in NortheastChina had no significant difference between right and left sides. Male andfemale data was different, as well as among different ages. Results of thisstudy,in some parts, were different from some domestic studies.Significant difference was foud between Chinese and foreigners.2. The female had a higher rate of “funnel-like”style of proximalfemur than the male. And the older had a higher rate of“chimney-like”style than the young. Correlation was found in each otherin many of these parameters.3. Ridian of femoral calcar can help design and select betterprostheses for THA.4. The tip of greater trochanter was less than1cm higher than thecenter of femoral head in mean. And this relationship could help rebuildthe length of lower limbs.5. The morphological characteristics of Chinese adult proximalfemurs should be paied attention in the design and placement ofprosthesis in THA according to the variability.