Preoperative magnetic resonance imaging evaluation of knee cartilage injury / 中华创伤骨科杂志

ABSTRACT

Objective To explore clinical value of magnetic resonance imaging (MRI) in preoperative risk assessment and choice of operation scheme for knee cartilage injury.Methods A retrospective study was conducted of the 69 cases of knee cartilage injury which had been confirmed by surgery between January 2013 and June 2014.They were 29 males and 40 females,aged from 15 to 76 years (average,46.9 years).All cases underwent preoperative 1.5 T MRI by a special diagnostic instrument for limbs.The injury was assessed after MRI according to the Outerbridge criteria to evaluate surgical risks and choose an appropriate operation scheme (drilling,micro-fracture or autoallergic cartilage grafting).The intraoperative observations were compared with the preoperative images.Results MRI found in the 69 patients 345 cartilage surfaces,of which 208 were abnormal.Of the abnormal ones,75 (21.7％) were grade Ⅰ which presented with intact or slightly eminent contour and dots or patches of low or high signals in the cartilage;39 (11.3％) were grade Ⅱ which presented with thinned cartilage,defects ＜ 50％ of the full thickness,or (and) indented or wavy cartilage surface,dots or patches of low or high signals in the cartilage,and dropsy signals in cavity;43 (12.5％) were grade Ⅲ which obviously thinned cartilage,defects ＞ 50％ of the full thickness,and massive dropsy signals in cavity;51 (14.8％) were grade Ⅳ which presented with full thickness defects of cartilage,subchondral bone exposure beneath the defcts,and abnormal adjacent tissues.The preoperative findings were in agreement with what were observed during surgery in terms of number and extent of cartilage injury.Conclusion Because MRI can exactly display knee cartilage injury in terms of location,degree,and size,it provides solid evidence for preoperative risk assessment and choice of operation scheme for knee cartilage injury.