Definition: The relative length of the ulna compared to the radius.
Neutral 0 (< 1mm)
Variations: Mcq ❓️
Positive Ulnar Variance: The ulna is longer than the radius. Positive +1, +2mm
Negative Ulnar Variance: The ulna is shorter than the radius.-1, -2mm
Associated Conditions:
Positive UV is associated with ulnar impaction syndrome, Kienbock’s disease, and TFCC tears.
Negative UV can cause ulnar abutment syndrome. Ulnocarpal Abutment Syndrome is a common source of ulnar sided wrist pain secondary to excessive impact stress between the ulna and the carpal bones (primarily lunate).
Imaging: X-ray with A-P views of the wrist. Measure the distance between two lines: one tangential to the articular surface of the ulna and perpendicular to its shaft, and another tangential to the lunate fossa of the radius and perpendicular to its shaft. A positive UV shows the ulnar tangent distal to the radial tangent, while a negative UV shows it proximal.
Ortho-Mentor Course 