急性髌骨脱位后内侧髌股韧带撕裂与股内斜肌损伤相关性的MRI分析

The MRI study of correlation between medial patellofemoral ligament tear and injury degrees of vastus medialis obliquus after acute patellar dislocation

目的 分析急性髌骨脱位后内侧髌股韧带（MPFL）损伤模式与股内斜肌（VMO）损伤程度的相关性.方法 回顾性分析79例急性髌骨脱位患者的MRI资料,所有患者均进行标准位置扫描.根据MPFL损伤模式分组,分为部分撕裂组、完全撕裂组;根据损伤部位分组,分为单纯股骨侧撕裂组、单纯髌骨侧撕裂组、单纯体部撕裂组及多发撕裂组,在冠状面和矢状面测量VMO撕裂抬升高度.计数资料应用χ2检验、计量资料（正态分布）采用t检验,对比不同MPFL损伤模式下VMO损伤发生率及其撕裂抬升高度的差异.结果 髌骨脱位后MPFL撕裂的发生率为96.2%（76/79）,VMO损伤的发生率为54.4%（43/79）.MPFL部分撕裂组、完全撕裂组VMO损伤的发生率分别为40.6%（13/32）和68.2%（30/44）,两者差异有统计学意义（χ2=5.727,P=0.017）.MPFL单纯髌骨侧撕裂组、单纯股骨侧撕裂组以及多发部位撕裂组VMO损伤的发生率分别为31.8%（7/22）、67.7%（21/31）、70%（14/20）,差异具有统计学意义（χ2=8.549,P=0.014）,单纯体部撕裂组因例数少（3例）没有进行统计.MPFL单纯股骨侧撕裂组和多发部位撕裂组VMO撕裂抬升高度（冠状面、矢状面）均明显高于单纯髌骨侧撕裂组,差异具有统计学意义（单纯股骨侧撕裂组与单纯髌骨侧撕裂组比较t值分别为5.888、9.110,单纯髌骨侧撕裂组与多发部位撕裂组比较t值分别为-6.066、-9.928,P值均〈0.05）;单纯股骨侧撕裂组和多发部位撕裂组比较,差异无统计学意义（冠状面t值为-0.609、矢状面为-1.792,P值均〉0.05）.结论 在急性髌骨脱位患者中,MPFL完全撕裂者较部分撕裂者更易并发VMO损伤,并且VMO撕裂抬升高度明显高于部分撕裂者;MPFL单纯股骨侧及多发部位撕裂者较单纯髌骨侧撕裂者更易导致VMO损伤,并且撕裂抬升高度明显高于单纯髌骨侧撕裂者.

Objective To discuss the relationship between the injury patterns of medial patellofemoral ligament（MPFL） and injury degrees of vastus medialis obliquus（VMO） after acute patellar dislocation（PD）. Methods Knee joint MRI was performed in 79 patients with acute PD. Images were acquired and evaluated using standardised protocols. Injury patterns of MPFL were grouped by severity （partial tear and complete tear）and location （isolated patellar-side tear （PAT）, isolated femoral-side tear （FEM） and combined tear （COM） ） for analysis of the prevalence of VMO injury. The VMO elevation was calculated on sagittal and coronal planes. Results The prevalence rates of MPFL tear and VMO lesion were 96.2%（76/79）and 54.4%（43/79）after acute PD.The prevalence rate of VMO lesion was 40.6%（13/32）and 68.2%（30/44）in the partial and complete MPFL tear subgroups,respectively.Complete MPFL tear subgroup showed higher prevalence rate of VMO lesion when compared with partial tear subgroup（χ2=5.727, P=0.017）. The prevalence rates of VMO lesion in the PAT, FEM and COM subgroups were 31.8% （7/22）, 67.7% （21/31） and 70% （14/20）, respectively. There were statistically significant differences among them（χ2=8.549,P=0.014）.About the mean VMO elevation,there were statistically significant differences between the complete and partial MPFL tear subgroups, the FEM and PAT subgroups, and the COM and PAT subgroups （P=0.00）. Conclusions Compared with partial MPFL tear, complete tear predisposes to VMO lesion and has a higher elevation of the torn VMO after acute PD.The femoral-sided and combined MPFL tears predispose to VMO lesion and have higher elevations of the torn VMO.