Ulnar impaction syndrome: MR imaging findings.
OBJECTIVE
To evaluate magnetic resonance (MR) imaging findings in ulnar impaction syndrome and changes after ulnar recession arthroplasty.


METHODS
MR imaging and arthroscopy were performed in 30 wrists in 27 patients (aged 15-62 years) in whom ulnar impaction syndrome was diagnosed on the basis of physical examinations. MR imaging was performed in 11 wrists before and after surgery. T1- and T2-weighted spin-echo images were obtained. Signal intensities in the lunate, triquetrum, and ulnar head were evaluated.


RESULTS
There was focal abnormal signal intensity of the ulnar aspect of the lunate in 87% of wrists, of the radial aspects of the triquetrum in 43%, and of the radial aspects of the ulnar head in 10% before surgery. The signal intensity of the abnormalities was decreased on T1-weighted and decreased or increased on T2-weighted images. After surgery, the signal intensity of the lunate shifted from low through slightly low to normal on T1-weighted and from low through high to normal on T2-weighted images.


CONCLUSIONS
Most ulnar impaction syndrome cases have characteristic focal signal intensity changes in the ulnar part of the lunate. The signal intensity often returns to normal after ulnar recession arthroplasty.
Department of Orthopaedic Surgery, Branch Hospital of Nagoya University, Aichi, Japan.
T
T
Imaeda
R
R
Nakamura
K
K
Shionoya
N
N
Makino
D000293:Adolescent; D000328:Adult; D001182:Arthroscopy; D002348:Carpal Bones / Q000473:pathology; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013577:Syndrome; D014457:Ulna / Q000473:pathology* / Q000601:surgery; D014955:Wrist Joint / Q000473:pathology*