Department of Radiology, Adelaide and Meath Incorporating National Children's Hospital, Tallaght, Dublin 24, Ireland.
Eur J Radiol. 2011 Jun;78(3):425-9. doi: 10.1016/j.ejrad.2009.11.001. Epub 2009 Dec 1.
The purpose of our study was to describe the magnetic resonance imaging (MRI) features of bipartite patella in asymptomatic patients.
The study was prospective in type and performed following institutional ethical committees approval. In total, 25 subjects were recruited into the study and informed consent obtained in each case. The local radiology database was utilised in conjunction with a clinical questionnaire to identify patients who had asymptomatic bipartite patella. Any patient with a history of trauma or symptomatic disease was excluded from the study. MRI imaging was performed in each case on a 1.5 T system using a dedicated knee coil and a standardised knee protocol. The images obtained were then analysed by two musculoskeletal radiologists in consensus.
Of the 25 subjects, there were 8 females and 17 males. The mean age was 34.6 years. All but one of the bipartite fragments were located on the superolateral aspect of the patella. In 23 cases, one fragment was identified. The average transverse diameter of the fragment was 12.8 mm. The average distance between the fragment and the adjacent patella in the axial plane was 1.46 mm. In addition, the cartilage overlying the patella and accessory fragment was intact in all cases. The average thickness of the patella cartilage at its border to the fragment was 2.4mm with an average ratio of the cartilage thickness of the fragment as compared with the cartilage thickness of the patella of 0.72. There was no evidence of high signal or bone marrow oedema on fluid sensitive sequences within either the patella or the fragment in any of the patients. Fluid was identified in the cleft between the patella and the fragment in the majority of cases.
Asymptomatic bipartite patella is characterised by intact but thinned cartilage along the border between the patella and the fragment, fluid between the cleft and a lack of any bone marrow oedema or high signal within the patella or its fragment.
本研究旨在描述无症状患者二分髌骨的磁共振成像（MRI）特征。
本研究为前瞻性研究，经机构伦理委员会批准。共招募 25 名受试者，并在每例中获得知情同意。利用局部放射学数据库结合临床问卷，识别出无症状二分髌骨的患者。排除有创伤史或有症状疾病的患者。在每个病例中，均在 1.5T 系统上使用专用膝关节线圈和标准膝关节协议进行 MRI 成像。获得的图像由两名肌肉骨骼放射科医生进行共识分析。
在 25 名受试者中，有 8 名女性和 17 名男性。平均年龄为 34.6 岁。除 1 例外，所有二分髌骨碎片均位于髌骨的外上侧。在 23 例中，发现 1 个碎片。碎片的平均横径为 12.8mm。在轴位上，碎片与相邻髌骨之间的平均距离为 1.46mm。此外，所有病例中髌骨和副髌骨上的软骨均完整。髌骨与碎片交界处的髌骨软骨平均厚度为 2.4mm，与髌骨软骨厚度相比，碎片软骨的平均比值为 0.72。在任何患者中，在敏感流体序列上均未发现髌骨或碎片内有高信号或骨髓水肿。在大多数情况下，可在髌骨和碎片之间的裂隙中发现液体。
无症状二分髌骨的特征是髌骨和碎片之间边界处的软骨完整但变薄，裂隙之间有液体，髌骨或其碎片内无骨髓水肿或高信号。
