A surgical instrument for the distraction or compression of bones or bone portions comprises a pair of elongate cross members pivotally coupled for relative movement having at one end a respective pair of handles and at the other end a respective pair of jaws. The jaws are generally parallel to each other and define a first plane within which the jaws are relatively movable, the space on both sides of the plane defining a work space between the jaws. The instrument further comprises a fulcrum supported by at least one of the cross members projecting into the work space and having an axis spaced from the jaws.