【摘要】 目的 通过动态髌股关节轴位摄片适合角（CA）的测量，对屈膝过程中髌骨轨迹进行研究，探讨髌骨轨迹异常的诊断及其分类。方法 选择15例（30膝）无与髌股关节有关症状或体征的志愿者作为对照组（A组），将43例（68膝）有膝前痛，临床检查诊断为髌骨排列异常病人分为3组：B组（外侧不稳组）19例病人（33膝），手推髌骨髌骨外侧移动增加，FAIRBANK征阳性；C组（内侧不稳组）8例病人（14膝），内推髌骨时其内移增加，同时诱发疼痛和恐惧，FAIRBANK征阴性，外推髌骨不会增加其外侧移动；D组（多项不稳组）16例病人（21膝），查体时会增加髌骨向内、外方向的移动，同时会诱发恐惧和疼痛，对每一病膝及正常对照膝拍摄屈膝15°、30°、45°、60°、90°髌股关节轴位X线片进行CA测量并对照分析，根据CA测量结果将D组中屈膝15° CA值小于-10°病人定为D1组（内→外不稳组），CA值大于+16°的病人定为D2组（外→内不稳组）。结果 A组屈膝各角度CA平均值均正常；B组屈膝各角度CA值均大于正常值，且屈膝15°～90° CA值有缩小趋势；C组屈膝各角度CA值均小于正常值，且屈膝15°～90° CA值由小到大；D1组和D2组CA值屈膝15°～90°变化最明显，其曲线完全相反。结论 动态髌股关节轴位摄片能对髌骨轨迹异常进行评价。
【关键词】 髌骨 膝关节 放射摄影术 诊断
［ABSTRACT］ObjectiveTo study the diagnosis and classification of abnormal patella tracking through dynamic axial patellofemoral X?ray image during knee flexing and measuring its congruence angle (CA). MethodsThis study was divided into the following four groups. Group A (control group): 15 volunteers (30 knees) without any knee symptoms or signs; Group B： 19 patients (33 knees) with lateral instability, with increased lateral excursion of the patella while being pushed, and positive FAIRBANK sign; Group C：eight patients (14 knees) with medial instability, with increased medial excursion of the patella and induced pain and fear while being pushed medially, but none demonstrated increased lateral patellar excursion while pushed laterally, FAIRBANK sign being negative; Group D: 16 patients (21 knees) with multi?directional instability, with increased excursion of the patella in both medial and lateral directions while being pushed medially and laterally, and pain and fear were induced as well. Dynamic axial radiographies of patella femoral joints with modified X?ray technique were made with knees flexing at 15, 30, 45, 60, and 90 degrees, and CA were measured and analyzed. Group D was further divided into two sub?groups according to CA measurement at knee flexing angle of 15 degrees. Those with CA<10 degrees were classified as Group D1 (medial→lateral instability); those with CA>16 as group D2(lateral→medial instability). ResultsIn group A, the average values of CA at each knee flexing angle were within normal range; those in group B were greater than normal values at all tested knee flexing angles, and there was a tendency to decrease the CA values with the increase of knee flexing angles; those in group C were lower than normal at all tested knee flexing angles. There was a tendency of the CA values along with the increase of knee flexing angles. The CA values were mostly changed in groups D1 and D2, but the curves in these two groups were reversed lusionThe dynamic axial patellofemoral joint imaging can be used to evaluate the patellar tracking abnormalities.
［KEY WORDS］patella; knee joint; radiography; diagnosis
髌骨轨迹异常是膝痛的主要原因，而且其症状酷似其他形式的膝内紊乱症。因为通过物理检查及以往设计的各种各样的X线技术都很难对髌骨的轨迹异常进行评价，因而在诊断上易于与其他疾病相混淆，给选择正确的治疗方法带来很大的困难。本文对43例病人68膝进行动态髌股关节轴位摄片，通过对在屈膝过程中髌骨轨迹的研究，探讨髌骨轨迹异常的诊断及其分类。
1 资料与方法
1．1 对象与分组
1997年8月～2004年2月，我院收治的临床诊断为髌骨轨迹异常病人43例，其中男14例，女29例；平均年龄45.5岁（25～72岁）。共68膝，左侧33膝，右侧35膝。43例病人均有膝前痛，间歇性膝关节肿胀，膝无力，由坐位站立行走时的关节交锁及膝关节的不安全感和移位感等症状。查体：所有病人有一项或更多的显示髌骨不稳的客观发现，即手法推移髌骨时髌骨内和（或）外移度增加，用此手法时病人有恐惧感和疼痛，内侧或外侧支持带紧张，内侧或外侧支持带处的压痛以及髌骨碾压试验阳性伴有轧砾和关节积液。另选15例无髌股关节症状和体征的志愿者作为对照组（A组）,其中男9例，女6例,平均年龄28.6岁(19～39岁)，共30膝。
将髌骨轨迹异常病人分为3组：B组(外侧不稳组)由19例病史和临床表现与髌骨外侧半脱位诊断一致病人组成，平均年龄49.0岁(26～72岁)，共33膝，查体时手推髌骨髌骨外侧移动增加，FAIRBANK征阳性［1］；C组(内侧不稳组)由8例持续前膝痛和不稳症状病人组成，平均年龄39.0岁(25～65岁)，共14膝，查体时手法内推髌骨，髌骨的内移增加，同时诱发恐惧感和疼痛，FAIRBANK征阴性，但外推髌骨则不会增加外侧移动及出现阳性FAIRBANK征；D组(多向不稳组)由16例因前膝痛和不稳而就诊的病人组成，平均年龄46.7岁(31～67岁)，共21膝，查体时会增加髌骨向内、外方向移动，同时会诱发恐惧和疼痛。根据文献［2～4］的判断标准，将D组中屈膝15° X线片上CA小于-10°的病人划分为D1组（内→外不稳组），将CA大于16°的病人划分为为D2组（外→内不稳组）。
1．2 检查方法
病人和正常志愿者仰卧于摄片台上，下肢置于自制的可调节屈膝角度的膝关节托架上，X线球管置于足下方朝向头侧，X线束近似与胫骨前缘平行，病人手持X线板置于髌股关节的平面，并与X线垂直，同时用力将X线板向下压，以防股部肌肉影响髌股关节在X线上成像，所有病人的68膝及对照的30膝均在股四头肌松弛状态下分别进行屈膝15°、30°、45°、60°、90°髌股关节轴位摄片检查。
