Analysis of age-related degenerative changes of the biceps brachii distal footprint.

The purpose of this study is to qualitatively and quantitatively describe the morphology of the biceps insertion on the radial tuberosity. Twenty-four preserved human elbows were carefully dissected and the insertions of the biceps conserved. The radius and the shape of the biceps insertion on the radial tuberosity were computerized using a three-dimensional digitizer. The length, width, and surface area of the footprints were measured. The soft tissue status of the muscle insertions and shape of the footprints were qualitatively described. The mean length of the biceps footprint was 24.1 ± 2.4 mm, the mean width was 11.1 ± 2.6 mm, and the mean area of the footprint was 219.0 ± 60.2 mm(2). Avascular, degenerate tissue fibers, consistent with tissue fibrosis were observed in 46% of the specimens. These changes may demonstrate natural changes of the distal biceps tendon and may improve our understanding of biceps tendinopathy and its prevalence.