Oblique ulnar shortening osteotomy by a single saw cut.

Ulnar shortening osteotomy is an effective treatment in patients with ulnar impaction syndrome. Accurate shortening and bony apposition can be obtained for a wide range of shortening lengths with a single-cut osteotomy technique. The saw kef produced by a single saw pass cuts a bony defect with parallel walls. The amount of shortening produced by using standard power bone saws can be increased by stacking as many as three blades together on the saw and by varying the angle at which the cut is made. The amount of shortening is a function of the angle at which the cut is made. The amount of shortening can be increased by a factor of twice the saw kerf if the cut is made at 60 degrees. We tabulated the shortening expected from over 100 combinations of power saw blades and cut angles. Using a series of experimental osteotomies, we demonstrated that the single-cut technique produces a more predictable amount of shortening than the technique of using two parallel cuts to remove a cuff of bone. The single-cut technique is useful for shortening any long bone.