Evaluation of ulnar styloid length.

Area of Science:

• Orthopedics
• Radiology
• Anatomy

Background:

• Ulnar styloid impaction syndrome awareness is low.
• Standard radiographic evaluation of ulnar styloid length typically uses posteroanterior (PA) views.
• Accurate assessment of ulnar styloid length is crucial for diagnosing impaction syndromes.

Purpose of the Study:

• To analyze the effect of different radiographic views on ulnar styloid length measurements.
• To compare the ulnar styloid-capitate ratio (SCR) with the ulnar styloid process index (USPI).
• To determine the most reliable method for assessing ulnar styloid length and impaction potential.

Main Methods:

• Measurements of the ulnar styloid were taken from 7 different radiographic positions in 69 patients' wrists.
• The ulnar styloid process index (USPI) and the ulnar styloid-capitate ratio (SCR) were calculated and compared.
• The SCR was defined as the ratio of ulnar styloid length to capitate bone length.

Main Results:

• The mean ulnar styloid length in standard PA radiographs was 4.4 +/- 1.2 mm.
• Average USPI was 0.21 +/- 0.11 and average SCR was 0.18 +/- 0.05.
• SCR showed a stronger correlation with ulnar styloid length and eliminated gender-based differences, unlike USPI.

Conclusions:

• USPI is recommended for identifying ulnar impaction potential.
• SCR is recommended for comparing ulnar styloid lengths between patients using neutral PA radiographs.
• For white patients, an SCR > 0.18 +/- 0.05 or styloid length > 6 mm suggests a long ulnar styloid.