High-resolution MRI using a microscopy coil for the diagnosis of recurrent lateral patellar dislocation.
OBJECTIVE
Magnetic resonance imaging (MRI) has been commonly used for the preoperative evaluation of recurrent lateral patellar dislocation (RLPD). The purpose of this study was to determine the usefulness of high-resolution MRI (HR-MRI) with a microscopy coil for diagnosing RLPD.


METHODS
The study group consisted of 15 patients with clinically diagnosed RLPD and 10 normal volunteers. All studies were performed on a 1.5-T MR system. First, conventional MRIs of the whole knee joint were obtained using the knee coil. Then HR-MRI scans using a microscopy coil in the medial aspect of the patella were obtained at the level of the superior pole of the patella, targeting the medial patellofemoral ligament (MPFL). The acquired HR-MRIs with RLPD were reviewed concerning the MPFL injury and the patellar injury.


RESULTS
The MPFL was distinguished as a separate ligament, and the layer structure of the patellar cartilage was visualized clearly in all volunteers. The MPFL injury was visualized in 12 cases (87%); it included discontinuity, thickening, and loosening. The patellar injury was visualized in 11 cases (73%), which included dissecans of the medial margin and cartilage injuries.


CONCLUSIONS
HR-MRI with a microscopy coil provides precise information of the MPFL and patellar cartilage injury for the diagnosis of RLPD.
Iwama
Yuki
Y
Department of Radiology, Kobe Graduate School of Medicine, 7-5-2 Kusunoki-cho, Kobe 650-0017, Japan. iwama@med.kobe-u.ac.jp
Fujii
Masahiko
M
Shibanuma
Hitoshi
H
Muratsu
Hirotsugu
H
Kurosaka
Masahiro
M
Kawamitsu
Hideaki
H
Sugimura
Kazuro
K
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007717:Knee / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D031222:Patellar Dislocation / Q000175:diagnosis*; D017847:Patellar Ligament / Q000473:pathology*