title: Correlation analysis between injury patterns of medial patellofemoral ligament and vastus medialis obliquus after acute first-time lateral patellar dislocation.
abstract: OBJECTIVE
  To evaluate the correlation between injury patterns of the medial patellofemoral ligament (MPFL) and vastus medialis obliquus (VMO) after acute first-time lateral patellar dislocation (LPD) in adults.
  
  
  METHODS
  Magnetic resonance imaging (MRI) was prospectively performed in 132 consecutive adults with acute first-time LPD. Images were acquired and evaluated using standardized protocols. Injury patterns of MPFL were grouped by location and severity for analysis of the prevalence of VMO injury.
  
  
  RESULTS
  MRI demonstrated VMO injury in 63 (47.7%) patients. Twenty (38.5%) and 43 cases (56.6%) were present in partial and complete MPFL tear subgroups, respectively. Compared with partial MPFL tears, complete tears showed a higher prevalence of VMO injury (P = 0.044). The mean coronal (28.5 mm) and mean sagittal VMO elevations (20.7 mm) were higher in the complete MPFL tear subgroup than in the partial tear subgroup (19.8 mm, P = 0.005; 11.9 mm, P < 0.001). No correlations were identified between the prevalence of VMO injury and location subgroups of MPFL injury (n.s.). Mean VMO elevations were higher in isolated femoral-side (FEM) and combined MPFL tear (COM) subgroups (mean coronal VMO elevation of 29 mm and mean sagittal VMO elevation of 20.8 mm in the FEM subgroup; mean coronal VMO elevation of 29.6 mm and mean sagittal VMO elevation of 23.1 mm in the COM subgroup) than in the isolated patellar-side MPFL tear (PAT) subgroup (P = 0.022, P < 0.001) (mean coronal VMO elevation of 20.7 mm and mean sagittal VMO elevation of 10.6 mm).
  
  
  CONCLUSIONS
  Complete MPFL tear predisposes to VMO injury and has a higher elevation of torn VMO after acute first-time LPD in adults. Isolated femoral-side and combined MPFL tears predispose to higher elevation of torn VMO.
  
  
  METHODS
  IV.
authors.affiliation: Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, 16766 Jingshi Rd, Li-Xia District, Jinan, 250014, China.
authors.forename: Guang-Ying
authors.initials: GY
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Shandong Provincial Corps Hospital of Chinese People's Armed Police Force, Jinan, 250014, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Shandong Provincial Qianfoshan Hospital of Shandong University, Jinan, 250014, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, 16766 Jingshi Rd, Li-Xia District, Jinan, 250014, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, 16766 Jingshi Rd, Li-Xia District, Jinan, 250014, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, 16766 Jingshi Rd, Li-Xia District, Jinan, 250014, China.
authors.forename: Su-Hui
authors.initials: SH
authors.lastname: Qu
authors.affiliation: Department of Orthopedics, Shandong Provincial Qianfoshan Hospital of Shandong University, Jinan, 250014, China.
authors.forename: Zheng-Wu
authors.initials: ZW
authors.lastname: Bai
authors.affiliation: Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, 16766 Jingshi Rd, Li-Xia District, Jinan, 250014, China. qydinghy@163.com.
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Ding
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D019637:Orthopedic Procedures; D031222:Patellar Dislocation / Q000000981:diagnostic imaging* / Q000601:surgery; D017847:Patellar Ligament / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D012421:Rupture / Q000473:pathology; D055815:Young Adult
keywords: Knee; Lateral patellar dislocation; Magnetic resonance imaging; Medial patellofemoral ligament; Vastus medialis obliquus