Picture above : Flexion deformity of the hips and of the knees after a 65 mm femoral lengthening.

In other words, this rehabilitation is quite specific, and should follow very precise guidelines to prevent inflammatory reactions of muscles and tendons, which in turn could induce bending deformities, stiffness, and complications.

Flexion deformity can be noted in cases of very large lengthening (40% - 60% of the initial length of the bone), or in cases of uncontrolled, passive stretching.