CASE 96
By: Dr. Aliya Sarhan Al Barwani
HISTORY: Middle age woman with wrist pain.
What are the findings?
What is the diagnosis?
What are the complication of ulnar positive variance?
FINDINGS:
Plain-Radiograph: Collapse, sclerosis of the Lunate with apparent widening of the adjacent joint space.
MRI: The Lunate is low in signal in T1WI.
The distal ulna is shorter than the radius (Ulnar negative variance).
DIAGNOSIS:
Osteonecrosis of the lunate (Kienbock’s disease) with ulnar negative variance.
Ulnar positive variance: Causes Ulnar impaction syndrome.
PEARLS AND DISCUSSION:
Kienbock’s disease is osteonecrosis of the Lunate. Associated ulnar negative variance is seen in 75% of the cases. Commonly seen in middle age adults in the dominant hand.
Ulnar negative variance is a condition known to place more load upon the lunate and causes disturbance of the blood supply, which ends with osteonecrosis. MRI examination is the key test in the diagnosis of early stages of Kienböck’s disease in the presence of unequivocal X-ray and CT examinations. In late stages, low signal in the lunate will be seen in T1WI and T2WI.
Ulnar positive variance is where the distal articular surface of the ulna is more distal when compared to the articular surface of the radius. It plays an important role in wrist pathology such as ulnar impaction syndromes.
FURTHER READING:
1. Bain GI and Yeo CJ. Kienböck Disease: Recent Advances in the Basic Science, Assessment and Treatment. Hand Surg. (2015)
2. Arnaiz J and Piedra T. Imaging of Kienböck disease. AJR Am J Roentgenol.(2014)
White C and Benhaim P. Treatments for Kienböck disease: what the radiologist needs to know. Skeletal Radiol. (2016)
