【摘要】 目的 通過動態髕股關節軸位攝片適合角（CA）的測量，對屈膝過程中髕骨軌跡進行研究，探討髕骨軌跡異常的診斷及其分類。方法 選擇15例（30膝）無與髕股關節有關症狀或體徵的志願者作為對照組（A組），將43例（68膝）有膝前痛，臨床檢查診斷為髕骨排列異常病人分為3組：B組（外側不穩組）19例病人（33膝），手推髕骨髕骨外側移動增加，FAIRBANK徵陽性；C組（內側不穩組）8例病人（14膝），內推髕骨時其內移增加，同時誘發疼痛和恐懼，FAIRBANK徵陰性，外推髕骨不會增加其外側移動；D組（多項不穩組）16例病人（21膝），查體時會增加髕骨向內、外方向的移動，同時會誘發恐懼和疼痛，對每一病膝及正常對照膝拍攝屈膝15°、30°、45°、60°、90°髕股關節軸位X線片進行CA測量並對照分析，根據CA測量結果將D組中屈膝15° CA值小於-10°病人定為D1組（內→外不穩組），CA值大於+16°的病人定為D2組（外→內不穩組）。結果 A組屈膝各角度CA平均值均正常；B組屈膝各角度CA值均大於正常值，且屈膝15°～90° CA值有縮小趨勢；C組屈膝各角度CA值均小於正常值，且屈膝15°～90° CA值由小到大；D1組和D2組CA值屈膝15°～90°變化最明顯，其曲線完全相反。結論 動態髕股關節軸位攝片能對髕骨軌跡異常進行評價。
【關鍵詞】 髕骨 膝關節 放射攝影術 診斷
［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
髕骨軌跡異常是膝痛的主要原因，而且其症狀酷似其他形式的膝內紊亂症。因為通過物理檢查及以往設計的各種各樣的X線技術都很難對髕骨的軌跡異常進行評價，因而在診斷上易於與其他疾病相混淆，給選擇正確的治療方法帶來很大的困難。本文對43例病人68膝進行動態髕股關節軸位攝片，通過對在屈膝過程中髕骨軌跡的研究，探討髕骨軌跡異常的診斷及其分類。
1 資料與方法
1．1 物件與分組
1997年8月～2004年2月，我院收治的臨床診斷為髕骨軌跡異常病人43例，其中男14例，女29例；平均年齡45.5歲（25～72歲）。共68膝，左側33膝，右側35膝。43例病人均有膝前痛，間歇性膝關節腫脹，膝無力，由坐位站立行走時的關節交鎖及膝關節的不安全感和移位感等症狀。查體：所有病人有一項或更多的顯示髕骨不穩的客觀發現，即手法推移髕骨時髕骨內和（或）外移度增加，用此手法時病人有恐懼感和疼痛，內側或外側支援帶緊張，內側或外側支援帶處的壓痛以及髕骨碾壓試驗陽性伴有軋礫和關節積液。另選15例無髕股關節症狀和體徵的志願者作為對照組（A組）,其中男9例，女6例,平均年齡28.6歲(19～39歲)，共30膝。
將髕骨軌跡異常病人分為3組：B組(外側不穩組)由19例病史和臨床表現與髕骨外側半脫位診斷一致病人組成，平均年齡49.0歲(26～72歲)，共33膝，查體時手推髕骨髕骨外側移動增加，FAIRBANK徵陽性［1］；C組(內側不穩組)由8例持續前膝痛和不穩症狀病人組成，平均年齡39.0歲(25～65歲)，共14膝，查體時手法內推髕骨，髕骨的內移增加，同時誘發恐懼感和疼痛，FAIRBANK徵陰性，但外推髕骨則不會增加外側移動及出現陽性FAIRBANK徵；D組(多向不穩組)由16例因前膝痛和不穩而就診的病人組成，平均年齡46.7歲(31～67歲)，共21膝，查體時會增加髕骨向內、外方向移動，同時會誘發恐懼和疼痛。根據文獻［2～4］的判斷標準，將D組中屈膝15° X線片上CA小於-10°的病人劃分為D1組（內→外不穩組），將CA大於16°的病人劃分為為D2組（外→內不穩組）。
1．2 檢查方法
病人和正常志願者仰臥於攝片臺上，下肢置於自制的可調節屈膝角度的膝關節托架上，X線球管置於足下方朝向頭側，X線束近似與脛骨前緣平行，病人手持X線板置於髕股關節的平面，並與X線垂直，同時用力將X線板向下壓，以防股部肌肉影響髕股關節在X線上成像，所有病人的68膝及對照的30膝均在股四頭肌鬆弛狀態下分別進行屈膝15°、30°、45°、60°、90°髕股關節軸位攝片檢查。