The forearm interosseous membrane transmits 60% of axial load from the radius to the ulna through its central band (the thickest, most oblique portion). The distal oblique bundle (DOB) contributes to DRUJ stability. In Essex-Lopresti injuries (radial head fracture with IOM rupture and DRUJ disruption), the entire longitudinal forearm stability mechanism fails, allowing proximal radial migration.
| Origin | Interosseous border of the radius (oblique fibres angled distally from radius to ulna) |
|---|---|
| Insertion | Interosseous border of the ulna |
| Actions | Transmits compressive forces from the radius to the ulna; maintains the radioulnar relationship during axial loading; the central band is the primary structure for longitudinal forearm stability |
|---|
Essex-Lopresti injury (radial head fracture + IOM disruption + DRUJ instability) is the most severe forearm instability pattern. Radial head excision alone produces proximal radial migration and DRUJ dislocation. Management requires radial head arthroplasty (or ORIF) to maintain longitudinal stability while the IOM heals or is reconstructed.
Combined radial head fracture and IOM rupture producing longitudinal forearm instability managed with radial head arthroplasty and IOM reconstruction.
