The hamatolunate facet: characterization and association with cartilage lesions--magnetic resonance arthrography and anatomic correlation in cadaveric wrists.
The objective of this study was to characterize the appearance of the hamatolunate facet using high-resolution magnetic resonance (MR) arthrography in cadavers and to correlate the presence of this anatomic variant with the presence of osteoarthritis in the wrist. High-resolution MR images of 22 cadaveric wrist specimens were obtained after tri-compartmental arthrography. Two readers in consensus analyzed the MR images and recoded the presence or absence of a hamatolunate facet. Geometric characteristics and cartilage and ligament integrity were analyzed. A third reader, who was blinded to the purpose of the study, recorded cartilage lesions of all the bones of the proximal and distal carpal rows. A hamatolunate facet was present in 11 of 22 wrists (50%). The mean coronal size of the lunate facet at the lunate (type II lunate) was 4.5 mm (range, 2-6 mm). The highest frequencies of cartilage lesions were seen in the scapho-trapezio-trapezoid joint (45.5%) and at the proximal pole of the hamate (54.4% and 40.9% for consensus reading/blinded reading, respectively). In cases with a hamatolunate facet, the frequency of cartilage lesions in the proximal pole of the hamate was 81.8% and 63.6% versus 27.3% and 18.2% without such a facet (chi-squared, P=0.01/ P=0.03). No correlation of the presence of a hamatolunate facet with interosseous ligament tears or lesions of the triangular fibrocartilage was seen. In conclusion, the hamatolunate facet is a very common anatomic variant. The presence of a hamatolunate facet is associated with cartilage damage in the proximal pole of the hamate.
Pfirrmann
C W A
CW
Department of Radiology, Veterans Administration Medical Center, San Diego, CA 92161, USA. christian@pfirrmann.ch
Theumann
N H
NH
Chung
C B
CB
Trudell
D J
DJ
Resnick
D
D
D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D014955:Wrist Joint / Q000033:anatomy & histology*