髌腱-股骨外侧髁摩擦综合征MRI表现及分析

MRI analysis of patellar tendon-lateral femoral condyle friction syndrome

目的探讨髌腱-股骨外侧髁摩擦综合征(PT-LFCFS)的MRI表现与相关参数。方法研究对象60例,收集临床和MRI均诊断为PT-LFCFS的患者30例作为研究组,收集同期无膝关节MRI髌下脂肪垫损伤者30例作为对照组。对比观察研究组与对照组的MRI征象,测量Install-Salvati指数(ISR)、髌腱-股骨外侧髁滑车关节面(PL-T)最短距离、胫骨结节-股骨滑车沟(TT-TG)距离、股骨外侧髁角(LFCA)、股骨外侧髁长度(LTL)和股骨外侧髁高度(LTH),统计两组病例髌腱炎、髌骨外侧支持带损伤、髌股关节炎、胫股关节炎及股四头肌腱炎的发病率,并对两组结果进行比较。结果PT-LFCFS组在质子密度加权成像(PDWI)脂肪抑制序列见髌下脂肪垫外上部局限性水肿,对照组无髌下脂肪垫水肿表现。PT-LFCFS组PL-T、LFCA小于对照组[(0.26±0.08)cm,(0.76±0.11)cm,t=20.913,P<0.001;(82.99±4.94)°,(100.52±5.07)°,t=13.565,P<0.001],ISR、TT-TG、LTL、LTH大于对照组[(1.41±0.12),(1.01±0.08),t=-14.649,P<0.001;(1.14±0.37)cm,(0.69±0.21)cm,t=-5.899,P<0.001;(2.19±0.21)cm,(1.98±0.12)cm,t=-4.784,P<0.001;(0.80±0.13)cm,(0.68±0.11)cm,t=-4.003,P<0.001]。PT-LFCFS组在髌股关节炎、髌骨外侧支持带损伤的发病率高于对照组[25(83.3%),2(6.7%),x^(2)=32.593,P<0.001;27(90%),1(3.3%),x^(2)=41.853,P<0.001]。两组间髌腱炎、胫股关节炎及股四头肌腱炎的发病率差异无统计学意义(P>0.05)。结论PT-LFCFS的MRI特征性表现是髌下脂肪垫外上部局限性水肿,PL-T、LFCA减小,ISR、TT-TG、LTL、LTH增大。PT-LFCFS患者中,髌股关节炎、髌骨外侧支持带损伤的发病率较高。

Objective To investigate the MRI finding and relative quantitative parameter associated with patellar tendon-lateral femoral condyle friction syndrome(PT-LFCFS).Methods The knee MRI of 60 patients with clinical and MRI findings of PT-LFCFS(30)and without Hoffa's fat pad injury(30)during the same period was retrospectively analyzed.The Install-Salvati index(ISR),shortest distance between the patellar tendon and lateral trochlear facet(PT-T),tibial tubercle to trochlear groove distance(TT-TG),lateral femoral condyle angle(LFCA),lateral trochlear length(LTL),and lateral trochlear height(LTH)were measured.The incidence of patellar tendonitis,lateral femoral retinacular injury,patellofemoral arthritis,tibiofemoral arthritis,and quadriceps tendonitis in both groups was analyzed.Results The PT-LFCFS group exhibited localized edema of the Hoffa's fat pads on fat suppressed proton density-weighted imaging(PDWI)whereas the Hoffa's fat pads were normal in the control group.The PT-LFCFS group had significantly smaller PL-T[(0.26±0.08)cm,t=20.913,P<0.001]and LFCA[(82.99±4.94)°,t=13.565,P<0.001]than those of the control group[(0.76±0.11)cm,(100.52±5.07)°]as well as significantly larger ISR(1.41±0.12,t=-14.649,P<0.001),TT-TG[(1.14±0.37)cm,t=-5.899,P<0.001],LTL[(2.19±0.21)cm,t=-4.784,P<0.001],and LTH[(0.80±0.13)cm,t=-4.003,P<0.001]values than those of controls[1.01±0.08,(0.69±0.21)cm,(1.98±0.12)cm,(0.68±0.11)cm].The incidence of patellofemoral arthritis(25/30,83.3%,x^(2)=32.593,P<0.001)and lateral patella retinacular injury(27/30,90%,x^(2)=41.853,P<0.001)in the PT-LFCFS group was significantly higher compared to the control group(2/30,6.7%;1/30,3.3%).There were no significant differences observed in the incidence of patellar tendonitis,tibiofemoral arthritis,and quadriceps tendonitis between the two groups5(P>0.05).Conclusion Characteristic MRI findings associated with PT-LFCFS include localized edema of the Hoffa's fat pad and decreased PL-T and LFCA along with increased ISR,TT-TG,LTL and LTH.