CT study of normal patellar anatomical morphology / 中华骨科杂志

ABSTRACT

Objective To investigate normal patellar morphology,then to explore its possible instructive significance in the design of patella prosthesis for Chinese people and in the process of resurfacing patella.Methods CT scan examinations were performed in 60 normal knees (left or right knee was selected randomly； scan region,from half proximal tibia to half distal femur) of 60 healthy Chinese adults (32 males,28 females； age range,18-54 years； mean age,33.7 years),then mimics software was used to reconstruct the 3-D morphology of each patella and new coronal and sagittal planes were created.Each patella's height,width,thickness,the position of the dome,the ratio of height/width,and the residual thickness after patella was resected at the level of the subchondral bone of the lateral facet during the stimulating process of patella resurfacing were measured or calculated.Results Patella of Chinese maleheight 31.95±2.77 mm,width 45.02±2.70 mm,thickness 22.38 ±1.63 mm,the residual thickness after patella was resected 13.18±1.62 mm； Patella of Chinese femaleheight 28.72±2.17 mm,width 39.57±2.57 mm,thickness 19.88±1.36 mm,the residual thickness after patella was resected 11.20±1.20 mm.Significant differences existed between male and female for all the above four parameters.Patella of Chinese malethe ratio of width/height 1.42 ±0.11,the position of the dome (medial 42.9％)； Patella of Chinese femalethe ratio of width/height 1.38±0.10,the position of the dome (medial 42.6％).No significant differences existed between male and female for the above two parameters.Conclusion The patella of Chinese people is small,thin and slim,especially in Chinese female.These findings should be considered in selecting or designing patella prosthesis to fit the Chinese people.For Chinese female,more attention should be paid to keep appropriate residual thickness after the patella was resected during the process of patella resurfacing.