Prosthesis Design Of Total Knee Arthroplasty And The Morphological Indexes Of Chinese Proximal Tibias

Objective To analyze the guiding significance to the designing of prosthesis by measuring of the morphologic dimensions data of the proximal part of the tibia of the osteotomied face.Methods This clinical trial was carried out in Department of Orthopedic Surgery, shanghai no.6 hospital from March 2005 to August 2006 in 168 patients(206 knees). They were measured during total knee arthroplasty. The morphologic dimensions data of the proximal part of the tibia of the osteotomied face were measured. All the measured data were involved in the statistical analysis. The different observational index was calculated; mean value and standard deviation of the above were summed up by SARS 7.0 software. Coefficient correlation and regression equation among the width of tibial platform and sagittal length of medial & lateral tibial platform .Results A total of 206 injured knee joints were involved in the result analysis. The proportion of each parameter of tibial platform was defined. All the knees were divided into three groups: Group A(body height <165cm , 94 knees), Group B(body heigt 165-175cm , 89 knees), Group C(body height >175cm , 23 knees).â‘ In Group A, the width of tibial platform and the sagittal length of medial tibial platform correlated to each other (P<0.05), coefficient correlation: 0.8246, regression equation: L=-11.8702+0.8341M. The width of tibial platform and the sagittal length of lateral tibial platform correlated to each other (P<0.05), coefficient correlation: 0.8478, regression equation: L=-10.6513+0.7197M.â‘¡In Group B, the width of tibial platform and the sagittal length of medial tibial platform correlated to each other (P<0.05), coefficient correlation: 0.8062, regression equation: L=-11.9522+0.8341M. The width of tibial platform and the sagittal length of lateral tibial platform correlated to each other (P<0.05), coefficient correlation: 0.8078, regression equation: L=-11.6233+0.7992M.â‘¢In Group C, the width of tibial platform and the sagittal length of medial tibial platform correlated to each other (P<0.05), coefficient correlation: 0.7234, regression equation: L=-12.2436+0.8298M. The width of tibial platform and the sagittal length of lateral tibial platform correlated to each other (P<0.05), coefficient correlation: 0.7529, regression equation: L=-10.7347+0.7289M. In Gronp A, medial-lateral dimension/anteroposterior dimension (ML/AP) is 1.62-1.81. In Group B, ML/AP is 1.56-1.77. In Group C ML/AP is 1.52-1.74. All above are larger than those in imported prosthesis.Conclusions The study measures and add up exactly geometrical morphological dimensions of Chinese knee joint, and provides reference data of distal part of the proximal part of the tibial of the osteotomied face. The author find ML/AP of the proximal part of the tibia of Chinese is larger than which of Western, especially in small Chinese women. The results are close to the Chinese anatomical structure so it can provid more scientific evidence to the designing and manufacturing of the knee joint prosthesis. The application of these data will improve the fitness degree of the prosthesis in order to elevate the clinical effect of the TKA.