Age-Related Variations in Volar Cortical Angle of the Distal Radius

Abstract

Background: The ideal volar locking plate for the treatment of distal radius fracture should anatomically fit the volar surface of the distal radius. The purpose of this study was to measure the volar cortical angle (VCA) of uninjured adult distal radii to determine how well the VCA matches that of modern volar locking plates and whether variations in the VCA are related to demographic factors. Methods: A retrospective radiographic analysis of 273 uninjured adult distal radii was performed. Patients were stratified into age quintiles: less than 27 years, 27 to 43 years, 44 to 51 years, 52 to 64 years, and 65 years or older. The VCA was measured on lateral wrist radiographs, and patient demographics, including age and sex, were collected. Multivariable linear regression analyses were performed to determine the relationship between VCA and demographic factors. Results: The VCA ranged from 23.2° to 42.6°, with a mean of 32.2° ( SD = 3.79). Mean VCA was 32.8 ( SD = 4.17) in the youngest cohort (<27 years) and 30.4 ( SD = 3.63) in the oldest cohort (>65 years). Mean VCA decreased with age, approximately 0.04° per year after adjusting for sex. Men had a 1.6° greater VCA than women after adjusting for age. Conclusion: Mean VCA was greater than the VCA of modern volar locking plates. The VCA decreased with age in both men and women, and men had a greater VCA than women. Such differences must be taken into account to avoid malreduction, tendon irritation, or intra-articular screw placement using current volar plate designs.

Anatomical Study of Volar Face of Distal Radius and Comparison With the Shape of Locking Volar Plates

“…These studies observed that the angles of volar inclination of the radius were greater in men. ( 7 , 19 - 21 Gandhi et al ( 3 described that the PCA decreases with age, and men have a higher mean PCA, suggesting that current locking plates fit better in older women. Kwon et al ( 11 studied differences between Caucasian and Korean individuals, noting that Koreans presented a greater width of the distal region of the radius compared to Caucasians, as well as Korean men when compared with Korean women.…”

“…Fractures in the distal end of the radius are frequent in an orthopedic surgeon's routine, being responsible for 18% of all fractures. [1][2][3][4] They present a bimodal distribution, affecting mainly children between the ages 10 and 14 and women over 50, the latter related to bone fragility. 5 Currently, several therapeutic options are available: plaster casts, external fixators, percutaneous pin fixation, and modern locking volar plates.…”

“…1,6 Locking volar plates were introduced in clinical practice in the 1990s, showing excellent biomechanical results, 1,7 with fewer complications related to soft tissues than dorsal plates 6,[8][9][10][11][12] and allowing early wrist movement. 3,13 The main indications for locking volar plate treatment are: unstable extra-articular fractures (especially in osteoporotic bones), most articular fractures, and vicious consolidations of the distal third of the radius. 14 Several studies demonstrate an incompatibility between plates and the anatomy of the radial distal end.…”

Load Distribution in Dorsally-Angulated Distal Radius Deformity Using Finite Element Analysis

“…Moreover, the volar cortical angle was reported as the angle formed by a straight line drawn along the volar surface of the distal radius and a line drawn parallel to the volar cortex. 18 The normal volar cortical angle of a man was reported from 30.4 to 34.1 . 18 In the model, the volar cortical angle was 31 .…”

“…18 The normal volar cortical angle of a man was reported from 30.4 to 34.1 . 18 In the model, the volar cortical angle was 31 . Five additional models were developed, based on the intact wrist model, to simulate the dorsally-angulated distal radius.…”