Bahk Y W, Park Y H, Chung S K, Kim S H, Shinn K S
Department of Radiology and Nuclear Medicine, Kangnam St. Mary's Hospital, Catholic University Medical College, Seoul, Korea.
J Nucl Med. 1994 May;35(5):855-62.
Chondromalacia patellae (CP) is an important cause of anterior knee pain. Two clinical types are known: one that typically affects young subjects and the one that affects older patients. The primary diagnostic approach is radiography reinforced with arthrography. A 99mTc-MDP bone scan is invaluable in the study of bone diseases especially when augmented with pinhole scintigraphy (PS). In this study previously unknown, specific sign of CP demonstrated by PS in six middle-aged and elderly patients is described.
Noting an increased patellar uptake in a planar spot view, a medial PS scan of the patella was taken to detail the uptake pattern using a 3-mm or 4-mm aperture pinhole collimator. The uptake pattern was analyzed in terms of location, definition, mode, grade and other associated changes, and correlated with radiographic and CT scan alterations.
The planar views showed patellar uptake to be diffuse and nonlocalizing in five patients and ill-defined and spotty in the remaining patient. In contrast, PS revealed small, spotty uptake well localized in the central retropatellar facet in all but one patient in whom uptake was segmental. A control PS study of 16 patients with their patellas involved by osteoarthritis (n = 6), rheumatic arthritis (n = 5) and Reiter's syndrome (n = 5) also revealed retropatellar uptake with or without anterior patellar uptake in every patient. The CP with localized osteolysis or osteopenia accumulated tracer intensely, whereas those without showed mild to moderate uptake.
Spotty tracer uptake occurring exclusively in the central retropatellar facet without other knee joint alteration appears pathognomonic of CP in older patients.
髌骨软化症（CP）是前膝痛的重要原因。已知有两种临床类型：一种通常影响年轻受试者，另一种影响老年患者。主要诊断方法是通过关节造影增强的X线摄影。99mTc-MDP骨扫描在骨疾病研究中具有重要价值，尤其是在与针孔闪烁显像（PS）联合使用时。本研究描述了PS在6例中老年患者中显示的CP的一种此前未知的特定征象。
在平面点片上注意到髌骨摄取增加后，使用3毫米或4毫米孔径的针孔准直器对髌骨进行内侧PS扫描，以详细观察摄取模式。从摄取位置、清晰度、方式、分级和其他相关变化方面分析摄取模式，并与X线摄影和CT扫描改变进行关联。
平面视图显示，5例患者的髌骨摄取呈弥漫性且无定位性，其余1例患者的摄取不清晰且呈斑点状。相比之下，除1例摄取为节段性的患者外，PS显示所有患者的小斑点状摄取均很好地局限于髌后中央小平面。对16例髌骨受累于骨关节炎（n = 6）、风湿性关节炎（n = 5）和赖特综合征（n = 5）的患者进行的对照PS研究也显示，每位患者均有髌后摄取，有或无髌前摄取。伴有局限性骨质溶解或骨质减少的CP患者示踪剂摄取强烈，而无此情况的患者则显示轻度至中度摄取。
仅在髌后中央小平面出现的斑点状示踪剂摄取，且无其他膝关节改变，似乎是老年患者CP的特征性表现。
