Roentgen Ray Reader: Ulnar Impaction Syndrome
Ulnar impaction syndrome is a degenerative disorder caused by chronic impaction between the ulnar head and the triangular fibrocartilage complex and the ulnar carpus. This results in degenerative fibrocartilage tear triangular chondromalacia of the lunate, triquetrum, and distal ulnar head, instability or a torn ligament lunotriquétral, and osteoarthritis of the distal radioulnar joint and ulnocarpal.
The most common predisposing factor include congenital positive ulnar variance (although neutral and negative ulnar variance can also be seen), malunion of the distal radius, premature physeal closure of the distal radius, and previous radial head resection. Ulnar impaction syndrome may also occur due to activities that cause excessive intermittent loading of the ulnar carpus.
Radiographs and CT may reveal subchondral sclerosis and cystic changes in the ulnar head, ulnar aspect of the proximal lunate, and proximal radial aspect of the triquetrum.As the disease progresses, osteoarthritis ulnocarpal can see in these areas.
MRI in the early stage of ulnar impaction syndrome shows fibrillation of the cartilage of the ulnar head and ulnar carpal. Later, hypointense T1 and T2 can be seen in the ulnar head, ulnar aspect of the proximal lunate (see above), and proximal radial aspect of the triquetrum. More advanced disease is characterized by sclerosis, which is of low signal intensity on both T1 and T2 images. Tears of the triangular fibrocartilage and lunotriquetral ligament may also be seen, although MR arthrography is better at demonstrating these findings.
Differential considerations include: Asymptomatic senescent changes : Lack of positive ulnar variance. Intraosseous ganglia : Area of lucency on radiographs that have sharp margins. No signal intensity change in the triquetrum or ulnar head. True cysts : Area of lucency on radiographs that have sharp margins. No signal intensity change in the triquetrum or ulnar head. Vascular groove : Central proximal radiolucent defect that communicates with the radiolunate joint space. Kienböck disease : More diffuse. Affects the radial half of the lunate bone. The triquetrum and ulnar head are not affected. References Cerezal L, del Piñal F, Abascal F, García-Valtuille R, Pereda T, Canga A .
Imaging findings in ulnar-sided wrist impaction syndromes. Radiographics. 2002 Jan-Feb;22(1):105-21.
Positive Ulnar Variance - Bookshelf
Magnetic resonance imaging in orthopaedics and sports medicine
O Positive ulnar variance is not required. O Ulnocarpal abutment represents the spectrum of findings in Palmer class 2 degenerative lesions of the TFC ...Techniques in Wrist and Hand Arthroscopy
Positive ulnar stress and fovea tests, in combination, are roughly 98% ... An X- ray series is then obtained to evaluate ulnar variance and to assess for the ...Imaging of orthopedic sports injuries
Mean ulnar variance was significantly more positive than established norms. ... The males averaged 2.82±1.94mm positive ulnar variance and the females ...Wrist disorders, current concepts and challenges
Although positive ulnar variance in Kienbock's disease is rare in Europe and the USA, it occurs frequently in Japan. To clarify whether Kienbock's disease ...Wrist arthroscopy
Their suggestion that persistent pain was related to positive ulnar variance was consistent with two other reports that showed the efficacy of combining ...Casual Walkthroughs Directory
Ulnar Variance - Wheeless' Textbook of Orthopaedics
negative ulnar variance is associated w/ Kienbock's disease ... note that with increasing age, ulnar variance tends to become more positive; ...
DarkerBlue - Ulna Variance as it Relates to Kienbock's Disease
A Japanese survey suggested that ulnar variance is highly unlikely to be an important ... 1. positive ulnar variance with the articular surface of the ulna ...
Ulnar Impaction Syndrome
The lower radio-cubital median or ulnar variance is neutral when its values are around 2 mm. It is positive when the radial point is above the cubital line. ...
Imaging Findings in Ulnar-sided Wrist Impaction Syndromes
osseous findings at radiography include positive ulnar variance in ulnar ... Ulnar impaction syndrome in a 32-year-old woman with significant positive variance and ...
Imaging Findings in Ulnar-sided Wrist Impaction Syndromes1
Ulnar impaction syndrome in a 32-year-old woman with significant positive variance and ... Ulnar impaction syndrome in a 32-year-old woman with significant positive ...