Ulnar variance: facts and fiction review article

Area of Science:

• Orthopedics
• Radiology
• Anatomy

Background:

• Ulnar variance, the relative length of the ulna to the radius, is influenced by genetics, age, and physical load.
• Previous studies linked negative ulnar variance to specific wrist pathologies, though this was not observed in our study.
• Positive ulnar variance is associated with detrimental effects on the ulnar side of the wrist.

Purpose of the Study:

• To investigate the role of ulnar variance in wrist pathology.
• To examine the relationship between ulnar variance and conditions like triangular fibrocartilage complex (TFCC) degeneration and ulnar impaction syndrome.
• To understand how ulnar variance affects the sigmoid notch morphology of the radius.

Main Methods:

• Analysis of ulnar variance measurements in relation to wrist pathology.
• Observation of patient data to correlate ulnar length with specific conditions.
• Utilizing wrist arthroscopy for enhanced diagnostic capabilities in ulnar wrist pain.

Main Results:

• Negative ulnar variance was not confirmed as a cause for Kienböck's disease, avascular necrosis of the scaphoid, or scapholunate dissociations in this study.
• Positive ulnar variance was found to be detrimental, leading to triangular fibrocartilage complex (TFCC) degeneration and perforation.
• Positive ulnar variance also contributes to cartilaginous wear of carpal bones, indicative of ulnar impaction syndrome.
• Ulnar variance influences the morphology of the radial sigmoid notch.

Conclusions:

• Positive ulnar variance poses a significant risk to the ulnar compartment of the wrist.
• Ulnar impaction syndrome and TFCC damage are key consequences of positive ulnar variance.
• Wrist arthroscopy offers a more precise method for diagnosing ulnar wrist pain, with ulnar variance being a critical factor.