The Correlation between the Injury Patterns of the Medial Patellofemoral Ligament in an Acute First-Time Lateral Patellar Dislocation on MR Imaging and the Incidence of a Second-Time Lateral Patellar Dislocation.
10.3348/kjr.2018.19.2.292
- Author:
Guang ying ZHANG
1
;
Hong xia ZHU
;
En miao LI
;
Hao SHI
;
Wei LIU
;
Lei ZHENG
;
Zheng wu BAI
;
Hong yu DING
Author Information
1. Department of Ultrasonography, Shandong Provincial Qianfoshan Hospital of Shandong University, Jinan 250014, China. qydinghy@163.com
- Publication Type:Original Article
- Keywords:
Patellar dislocation;
Knee;
Medial patellofemoral ligament;
Recurrence;
MRI
- MeSH:
Follow-Up Studies;
Humans;
Incidence*;
Knee;
Ligaments*;
Magnetic Resonance Imaging*;
Patellar Dislocation*;
Prospective Studies;
Recurrence;
Tears
- From:Korean Journal of Radiology
2018;19(2):292-300
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To evaluate the correlation between the injury patterns of the medial patellofemoral ligament (MPFL) on magnetic resonance imaging in an acute first-time lateral patellar dislocation (LPD) and incidence of a second-time LPD. MATERIALS AND METHODS: Magnetic resonance images were prospectively analyzed in 147 patients after an acute first-time LPD with identical nonoperative management. The injury patterns of MPFL in acute first-time LPDs were grouped by location and severity for the analysis of the incidence of second-time LPD in a 5-year follow-up. Independent t tests, chi-square tests and Kruskal-Wallis tests were performed as appropriate. RESULTS: Forty-six cases (46/147, 31.3%) of second-time LPD were present at the 5-year follow-up. Fourteen (14/62, 22.6%) and 31 cases (31/80, 38.8%) were present in the partial and complete MPFL tear subgroups, respectively. Twenty-five cases (25/65, 38.5%), 11 cases (11/26, 42.3%), and 8 cases (8/47, 17%) were present in the isolated femoral-side MPFL tear (FEM), combined MPFL tear (COM), and isolated patellar-side MPFL tear (PAT) subgroups, respectively. Compared with the partial MPFL tears, complete tears showed higher incidence of a second-time LPD (p = 0.04). The time interval between the two LPDs was shorter in the complete MPFL tear subgroup (24.2 months) than in the partial tear subgroup (36.9 months, p = 0.001). Compared with the PAT subgroup, the FEM and COM subgroups showed a higher incidence of a second-time LPD (p = 0.025). The time intervals between the two LPDs were shorter in the FEM and COM subgroups (20.8 months and 19.2 months) than in the PAT subgroup (32.5 months, p = 0.049). CONCLUSION: A complete MPFL tear, isolated femoral-side tear and combined tear in a first-time LPD predispose a second-time LPD.
