Heterotopic ossification or unusual foramen in radius?

Abstract

The interosseous membrane (IOM) runs obliquely from radius to ulna attached to their respective interosseous borders. The membrane provides surface for attachment for muscles; stabilizes the radius and ulna during forearm rotation and actively transmits forces from the radius to the ulna. IOM is an occasional site for heterotopic ossification (HO) that involves development of mature lamellar bone, in a variety of soft tissues such as muscles, ligaments and other soft tissues causing significant functional limitation of upper limb. We describe unusual findings equivocal of congenital or acquired features in a dry adult radius where two thick bony spurs/processes emerging from the middle third of interosseus border approach towards each other joined by a thin bony fragment to form a huge foramen 2.4 cm in length and 6 mm in width abutting an uneven rough area of about 3.6mm x 1.6 mm on anterior surface. A prominent groove leading to a foramen at its junction with the shaft was present on the posterior surface of the bone. Knowledge of such HO as anatomical variants or possible sequel of trauma or neurological insult is indispensible and call for further research and trials to obviate such complications.