A fixation clamp for use in an external fixation system for holding bone fragments adjacent to each other with the help of fixation elements has at least one clamping assembly having a pair of jaws with at least two different size grooves to accommodate a bone fixation element such as a pin or rod. An alternate clamping assembly has at least three grooves wherein at least two of the grooves have a different size adapted to accommodate a correspondingly sized bone fixation element such as a bone pin. The longitudinal axes of the grooves define a polygon. The jaw pairs can be rotated about a central longitudinal axis to present different size reception cavities towards the pins or rocks depending on their diameter.

The present invention provides body anchored protraction devices. The protraction devices direct the negative forces of protraction over a large surface area on the chest and abdomen of a patient. The protraction devices employ a cantilever support rod and ultra-low friction joints to enable low compression on the head without restricting free movement.