膝骨关节病股骨后髁偏心距和偏心率特点及其与胫骨平台后倾角相关性分析

Characteristics of posterior condylar offset and ratio in osteoarthritis and relationship between posterior condylar offset/posterior condylar offset ratio and posterior tibial slope

目的比较中国人群不同性别、不同级别膝骨关节病患者股骨后髁偏心距(posterior condylar offset,PCO)及偏心率(posterior condylar offset ratio,PCOR)差异,分析股骨后髁偏心距和偏心率与胫骨平台后倾角(posterior tibial slope,PTS)的影像学相关性。方法纳入2018年2月至2018年6月首都医科大学附属北京友谊医院膝骨关节病患者200例,男性63例(112膝),女性137例(249膝),通过膝关节标准正侧位片评估膝骨关节病严重程度,测量PCO、股骨远端直径(anterior-posterior dimension,ACP)及PTS,计算PCOR(PCO/ACP)。应用双因素方差分析比较不同性别、不同级别膝骨关节病患者PCO/PCOR差异。应用Pearson相关分析探索膝骨关节病患者PCO/PCOR与PTS的相关性。结果男性PCO较女性更大;男女患者PCOR差异无统计学意义。不同级别间女性患者PCO及PCOR差异无统计学意义。男性Ⅱ级患者PCO较Ⅲ/Ⅳ级患者偏小(P=0.004,P=0.008),而Ⅲ级与Ⅳ级患者PCO差异无统计学意义。不同级别间男性PCOR亦差异无统计学意义。同时PCO与PTS不具有相关性,且不受性别或级别因素影响;PCOR与PTS的关系与级别有关,与性别无关:Ⅱ级患者PCOR与PTS具有相关性(r=0.226 9,P=0.02),Ⅲ级及Ⅳ级患者无类似相关性。结论膝骨关节病的疾病进展对男性患者PCO的影响较女性更大。疾病进展所致骨质增生与骨赘形成不影响股骨远端的解剖学特点,但对股骨与胫骨后间室解剖结构的相关性有一定影响,随着疾病进展,两者原有的相关性逐渐消失。

Objective To analyze the difference of posterior condylar offset(PCO) and posterior condylar offset ratio(PCOR) in different sex or level groups and figure out the relationship between the PCO/PCOR and posterior tibial slope(PTS).Methods Totally 200 patients diagnosed with osteoarthritis of knee during February 2018 to June 2018 were rolled in,including 63 men(112 knees) and 137 women(249 knees).The osteoarthritis level was evaluated,PCO and anterior-posterior dimension(ACP) of distal femur was measured and the PCOR(PCO/ACP) was evaluated through anterior and lateral radiographs of the knee.Two-ways ANOVA was used to analyze the difference of PCO/PCOR in different groups,Pearson relation analysis was used to analyze the relationship between the PCO/PCOR and PTS.Results The PCO of male was larger than level-matched female;there was no difference in PCOR between male and female.There was no difference in PCO and PCOR of female among three levels.The male in level Ⅱ have smaller PCO than level Ⅲ and Ⅳ(P=0.004,P=0.008),no more difference found between level Ⅲ and Ⅳ;and there was no difference exists in PCOR of male among three levels.PCO was not related to PTS in neither sex nor level groups,the relationship between the PCOR and PTS only depends on the level rather than the sex,and this relationship only exists in level Ⅱ(r=0.226 9,P=0.02).Conclusion The osteoarthritis progression has much more influence on male than female.Hyperostosis and osteophyte have no effect on anatomical characteristics of distal femur,but on the anatomical relationship between femur and tibia.The relationship between PCOR and PTS is gradually disappearing with disease progression.