The anatomy of the bicipital tuberosity and distal biceps tendon

Abstract

The anatomy of the distal biceps tendon and bicipital tuberosity (BT) is important in the pathophysiology of tendon rupture, as well as surgical repair. Understanding the dimensions of the BT and its angular relationship to the radial head and radial styloid will facilitate surgical procedures such as reconstruction of the distal biceps tendon, radial head prosthesis implantation, and reconstruction of proximal radius trauma. We examined 178 dried cadaveric radii, and the following measurements were collected: radial length, length and width of the BT, diameter of the radius just distal to the BT, distance from the radial head to the BT, radial head diameter, width of the radius at the BT, radial neck-shaft angle, and styloid angle. Furthermore, the morphology of the BT ridge was defined as smooth (absent), small, medium, large, or bifid. Of the specimens, 48 were further analyzed with a computed tomography scanner at the level of the BT to determine the distance to traverse both the anterior and posterior cortex and the anterior cortex alone. Eighteen fresh-frozen cadaveric elbows were dissected, and the insertion footprint of the distal biceps tendon was defined. The BT has a mean length of 22 +/- 3 mm and a mean width of 15 +/- 2 mm. The tendon insertion footprint is a ribbon-shaped configuration on the most ulnar aspect of the BT, and it occupies 63% of the length and 13% of the width of the BT. The BT ridge is absent in 6% of specimens and bifid in 6%, and the remaining 88% of specimens have a single ridge that may be classified as small, medium, or large. The mean diameter of the radial head is 22 +/- 3 mm. The mean radial neck-shaft angle is 7 degrees +/- 3 degrees , and the mean BT-radial styloid angle is 123 degrees +/- 10 degrees . None of the measurements correlated with patient age, sex, or race. We concluded that the morphology of the BT ridge is variable. The insertion footprint of the distal biceps tendon is on the ulnar aspect of the BT ridge. The dimensions of the radius and BT are applicable to several surgical procedures about the elbow.