The effects of partial and total interosseous membrane transection on load sharing in the cadaver forearm

Abstract

This study was performed to examine the effects of partial and total transection of the interosseous membrane (IOM) on load transfer in the foream. Twenty fresh frozen forearms were instrumented with custom designed load cells placed in the proximal radius and distal ulna. Simultaneous measurements of load cell forces, radial head displacement relative to the capitellum, and local tension within the central band of the IOM were made as the wrist was loaded to 134 N with the forearm at 90" of elbow flexion and in neutral pronation supination. For valgus elbow alignment (radial head contacting the capitellum), mean force carried by the distal ulna was 7.1% of the applied wrist force and mean force transferred from radius to ulna through the IOM was 4.4%. For varus elbow alignment (mean 2.0 mm gap between the radial head and capitellum), mean distal ulna force was 28Yn and mean IOM force was 51%. Section of the proximal and distal one-thirds of the IOM had no significant effect upon mean distal ulnar force or mean IOM force. Total IOM section significantly increased mean distal ulnar force for varus elbow alignment in all wrist positions tested. The mean level of applied wrist force necessary to close the varus gap (89 N) decreased significantly after both partial IOM section (71 N) and total IOM section (25 N). The IOM became loaded only when the radius displaced proximally relative to the ulna, closing the gap between the radius and capitellum. As the radius displaced proximally, the wrist becomes increasingly ulnar positive, which in turn leads to direct loading of the distal ulna. This shift of force to the distal ulna could present clinically as ulnar sided wrist pain or as ulnar impaction after IOM injury.

Experimental and finite element analysis of the rat ulnar loading model—correlations between strain and bone formation following fatigue loading

“…This result indicates that in the region of interest, the ulna is the primary load-bearing bone. Load sharing between the ulna and the radius has also been observed in the human forelimb (Birkbeck et al, 1997;DeFrate et al, 2001;Markolf et al, 2000;Shepard et al, 2001). Second, the strain gage data indicate that there is only an 8% difference in the ratio of tensile to compressive strain at the ulnar mid-shaft in the intact forelimb compared to the ulna-only condition.…”

Form and function of the oblique cord (chorda obliqua) in anthropoid primates

“…Because of its fiber orientation, the oblique cord is not likely to be involved in transferring force from the radius to the ulna during axial loading activities, contrary to reports of the interosseous membrane (Morris 1879;Schneiderman et al 1993;Birkbeck et al 1997;Skahen et al 1997;Markolf et al 1998;Pfaeffle et al 1999;McGinley et al 2001;Shepard et al 2001;Kaufmann et al 2002;but see Halls and Travill 1964). As the forearm is compressed and the radius is shifted proximally against the capitulum, the fibers of the interosseous membrane, which run from the radius proximally to the ulna distally, become taut and the load is shifted from the radius to the ulna through the membrane.…”

Reconstruction of the interosseous membrane of the forearm with a graft substitute: A cadaveric study

“…10,14 The maximum load applied was 134 N. All testing was performed with the wrist in neutral position with regard to supination and pronation. This was established by aligning the plane of the 3 potted metacarpals with the flexion-extension plane of the elbow.…”

“…3,8,9 Although the triangular fibrocartilage complex (TFCC) and the annular ligament maintain the proximal and distal articulations between the radius and ulna, respectively, the IOM is the primary stabilizer of the radius after radial head excision. 8,10 Interosseous membrane reconstruction has been studied in cadaveric models and has been performed to a limited degree in patients for the treatment of LRUD. 8,[11][12][13] ( Meeting, 2000).…”