Abstract
Purpose: We undertook a primarily cadaveric study of trabecular architecture of olecranon to link theory of biomechanics and morphological trabecular patterns of olecranon and secondly compare with real-life trabecular pattern in CT scans.
Methods & Results: Eight pairs of ulnae (fresh-frozen bones) were obtained from cadavers following road traffic accidents, aged 25 to 60 (mean 34 years). None suffered from previous pathology of elbow. Half of the ulnae were sliced longitudinally, each slice 2–3 mm thick (Group I), and the other half vertically (Group II). After they were radiographed, orientation of trabeculae was studied. CT scans of 8 patients (Group III), originally performed for investigation of fractures of radial head, were studied for comparison of real life trabecular pattern of olecranon.
In Group I, two main sets of trabeculae were observed. The first set consists of three bundles, which arise from anterior cortex and support subchondral area – the posterior third bundle curves and spreads to posterior cortex of olecranon. The second set arises from posterior cortex and terminates under subchondral area. In Group II, trabeculae subtend a 900 angle to articular surface. CT scans of 8 patients (Group III), originally performed for investigation of fractures of radial head, ascertained real-life trabecular pattern of olecranon and confirmed cadaveric observations.
Conclusion: Trabeculae of olecranon comprise a set to resist compressive loading and a further set to resist tensile stresses. Thicker trabeculae coincide with maximal loading. Prosthetic design of elbow should take into account the trabecular pattern to facilitate stress absorption.
Correspondence should be addressed to BOSA at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PE, England.
