A splint positionable about a user's hand for treating phalanx fractures includes a flexible body having a first opening for receiving a thumb therethrough and a second opening for allowing selected metacarpals to extend distally therethrough. The present invention further includes a mechanism for maintaining the end portions at selected spatial relationships and a flexible aluminum plate for engaging fractured metacarpals while allowing medial and distal metacarpal phalangeal joints to move along unrestricted paths respectively. The splint further includes a mechanism for adjusting a length of the plate so that the fractured metacarpals can be adapted between mobile and immobile positions.