膝关节软骨下骨局灶性病变与应力改变的相关性研究

The Relationship between the Stabilizer Failure and the Subchondral Focal Lesions of the Knee

目的研究膝关节软骨下假囊肿(osteoarthritis subchondral pseudocyst,OAPC)、自发性骨坏死(spontaneous osteonecrosis of the knee,SONK)、剥脱性骨软骨炎(osteochondritis dissecans,OCD)及其他软骨下局灶性MR T2WI高信号(T2WI high signal,T2HS)改变与膝关节软骨下骨应力改变的关系。资料与方法搜集MRI显示的膝关节软骨下局灶性病变115例,其中OAPC27例,SONK31例,OCD13例,T2HS44例。分析引起膝关节软骨下骨应力改变的因素。结果95例(82.6%)患者有半月板撕裂及软骨损伤,并与软骨下骨局限性病灶相对应。20例无半月板撕裂及软骨损伤或有损伤但与软骨下骨病灶不对应的患者中,有18例至少都有前和/或后交叉韧带撕裂,另2例无韧带撕裂,但有明显的膝关节过度使用史。T2HS和OCD患者病程较OAPC和SONK短,T2HS没有骨形态改变,X线平片和CT表现正常。结论膝关节OAPC、SONK、OCD及T2HS与软骨下骨承受应力改变密切相关,应力增加可能为其共同病因,建议将SONK、OCD命名为"应力性骨坏死",T2HS命名为"应力性骨挫伤"。

Objective To evaluate the relationship between the subchondral focal lesions （SFL）of the knee, including osteoarthritis subchondral pseudocyst （ OAPC ）, spontaneous osteonecrosis of the knee （ SONK）, osteochondritis dissecans （OCD） ,T2WI high signal （T2HS） and abnormal stress distributions of the knee joint. Materials and Methods 115 patients with SFL by MRI were prospectively collected,according to the criteria described in the literature for the above disease. There were 27 patients of OAPC,31 SONK patients, 13 OCD patients and 44 T2HS patients. The factors involving the change of stress distributions of the knee joint were analyzed. Results The meniscus tear rate were 82.6% （95/115） in four groups ,which lesion just corresponding to the SFL. At least one of ACL or PCL tear existed at the 90% （18/20） of 20 cases without meniscus and cartilage injuries,or which lesions not corresponding to the SFL. Only 2 cases without meniscus tear and ligament tear had the history of overuse of the knee. The duration of T2HS and OCD were shorter than that of OAPC and SONK. The apparent of the plain film and CT scan were normal in patients with T2HS. Conclusion The OAPC, SONK, OCD and T2HS were strongly related to the factors associated subchondral focal overload. So their pathogenesis might be due to abnormal stress distribution of the knee joint. It is suggested that the stress osteonecrosis should be instead of SONK and OCD as one entity,T2HS should be nominated focal stress contusion of bone.