[Femoral fractures in school age (6th-12th year)]

The femoral fracture is a paradigme for problems arising in fracture of the growing skeleton: length recovering growth and overgrowth, axial and rotational correction during physiological variation of the anteversion of the femoral neck will be discussed and their impact considered. Different types of overgrowth are accounted for. Our own patients, treated conservatively, showed a mean initial shortening of 0.85 cm. Their mean total overgrowth was 0.6 cm, so that their final grown-up leg length was -0.25 cm on the fractured side. Our small series did not indicate, that a consolidation with a modest angulation of less than 20 degrees and/or an initial shortening of less than 2 cm gave rise to a final over-length of some importance. The anteversion of the femoral neck of the broken leg compared with the other leg showed a mean difference of 13 degrees. None of the patients showed an abnormal gait. We discuss the unanswered question, if torsion deformities will be spontaneously corrected by growth-dependent modification of the anteversion of the femoral neck alone or by detorsion of the diaphysial femur too. We present the modalities of conservative treatment and the indications of operative treatment. We finally will raise the problem about the nature of the bone-remodeling mechanisms: role of the vascular distribution, of tissue hormones and of the streaming potentials. The hypothesis of streaming potentials forming the short-time memory of bone, and their transformation into a pattern of bipolar collagen fibres is fascinating.