The bicipital groove as a landmark for orientation of the humeral prosthesis in cases of fracture.

Abstract

We studied 45 dry cadaveric humeri to determine whether the bicipital groove of the humerus can be used as a landmark for a proper, individualized orientation of a humeral prosthesis, especially in the case of a fracture. We performed 3 computed tomography sections (at a level just below the lower portion of the head, at the middle of the humeral head, and at a distance 5 cm below the first section), and we used special software for 3-dimensional image processing. To reproduce the individual posterior version of the head, when a humeral prosthesis is implanted for fracture, the lateral fin of the prosthesis should be a mean distance 5.2 +/- 2.6 mm (-1.5 to 10.7 mm) from the posterior edge of the bicipital groove. If the lateral fin of the humeral prosthesis seats just behind the posterior edge of the bicipital groove, a difference of -6.3 degrees to 41.7 degrees from the normal posterior version occurs. A new, simple methodology for an individualized posterior version of a humeral prosthesis in cases of fracture is proposed. We applied this in 6 consecutive patients with fracture of the humeral head that required hemiarthroplasty.