Biochemical composition and histologic structure of the forearm interosseous membrane☆☆☆★

Abstract 

Purpose: The purpose of this study was to determine the structure and composition of the forearm interosseous membrane (IOM). Methods: The IOM of 12 cadaver forearms was fixed in formalin. After fixation 5 individual IOM fiber bundles per arm were separated by dissection, excised, and processed with hematoxylin-eosin, trichrome, and Verhoff-vanGeison stains. Nine additional fresh forearms were dissected and 5 IOM fiber bundles per arm were analyzed using the hydroxyproline assay. Bundles were evaluated at ulnar, central, and radial locations. Results: Histologic analysis of the IOM bundles obtained from the 12 fixed forearms showed an abundance of collagen in the main bundle central location (84% ± 7.8%). A progressive increase in collagen was noted from distal to proximal bundles (r =.72). The hydroxyproline assay of collagen content of the main IOM bundle's central location from the 9 additional fresh forearms was 99.3% ± 16.5%. There was no difference between bundles or location (power = 0.25 and 0.46). Conclusions: We found that the IOM possesses a large collagen content arranged in fibrillar structures surrounded by elastin. Collagen was abundant in the proximal bundles and decreased in the distal bundles. (J Hand Surg 2003;28A:503-510. Copyright © 2003 by the American Society for Surgery of the Hand.)

Keywords:  Interosseous membrane, forearm, histology, biochemical