Tensile properties of the interosseous membrane of the human forearm.
The interosseous membrane is a structure deep in the forearm that joins the radius and the ulna. It is made up of membranous and ligamentous regions. Two main ligamentous structures have been described: a prominent central fiber group, the "central band," and a smaller proximal fibrous band, the "oblique cord." Many authors believe that the central band plays a biomechanical role in the normal and fractured forearm and that it may function much like a ligament. The objective of this study was to determine the tensile properties of the central band. Eighteen fresh frozen forearms from cadavers (45-70 years of age, both sexes) were used. A fiber bundle of the central band was subjected to a uniaxial tensile test to failure in a materials testing machine, and its tensile properties were calculated. Stiffness, ultimate load, and energy absorbed to failure were expressed as a function of specimen width. The central band structure had a stiffness of 13.1 +/- 3.0 N/mm per mm width and an ultimate load of 56.6 +/- 15.1 N per mm width (mean +/- SD). The tissue of the central band displayed a modulus of 608.1 +/- 160.2 MPa, ultimate tensile strength of 45.1 +/- 10.3 MPa, and strain at failure of 9.0 +/- 2.0%. This study demonstrated that the central band is comprised of strong tissue. The material properties of the central band compare with those of patellar tendon: modulus is 120% and ultimate tensile strength is 84% that of patellar tendon. As a structure, the interosseous membrane is stiff and capable of bearing high loads. Although load distribution across the central band is unknown, a 1.7 cm wide, evenly loaded homogenous portion of the central band would possess a stiffness comparable with that of the anterior cruciate ligament. The results of this study provide a basis for future analyses of radioulnar stability and load transfer.
Department of Orthopaedic Surgery, University of Pittsburgh, PA 15213, USA.
H J
HJ
Pfaeffle
M M
MM
Tomaino
R
R
Grewal
J
J
Xu
N D
ND
Boardman
S L
SL
Woo
J H
JH
Herndon
D000368:Aged; D002102:Cadaver; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D008022:Ligaments / Q000502:physiology; D008297:Male; D008566:Membranes / Q000502:physiology; D008875:Middle Aged; D011884:Radius / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D013718:Tensile Strength; D014457:Ulna / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D016474:Weight-Bearing / Q000502:physiology