Bone overgrowth following diaphyseal femoral fracture in children

Abstract EN

Limb length discrepancy is the most common complication reported after femoral shaft fractures in children, usually resulting from overgrowth of the injured femur.

The exact cause of this overgrowth is still not known but it has been attributed to age, gender, fracture type, fracture level, handedness and amount of overriding of the fracture fragments.

This study aimed to evaluate femoral length discrepancy and rate of femoral overgrowth after one year of union following diaphyseal fracture of femur in children and find possible factors that accelerates this phenomenon.

A 34 femora with femoral shaft fractures were included in study, age ranged (1.

5-15yrs.), 26 were males and 8 were females, 19 were treated by hip spica, 15 were treated by open reduction and internal fixation.

Normal and fractured femoral length were assessed both clinically and radiologically at time of union and one year later.

Clinically from anterior-superior iliac spine to medial knee joint line and radiologically by measuring distance between most proximal bony point of femur and distal mid intercondylar line.

Radiologically, 97 % of femora were shortened at time of union, 26% of them remained shortened one year later, Clinically, overgrowth occurred in 76.

5 % of cases (average 0.

4cm.

/ yr.), while radiologically occurred in all (100 %) cases (average of 0.

8 cm.

/ yr.).

In conclusion, x-ray of both femora in one film is relatively safe technique for femoral length assessment compared to other patterns of radiological assessment, and more accurate than clinical assessment.

Proximal-third and spiral fractures in children younger than 8 years had greater tendency to correct shortening.

The greatest and significant overgrowth occurred within first year after injury.

The overgrowth phenomenon is physiological response to trauma rather than compensatory to the discrepancy.

Sex and side of fracture did not seem to have any significant influence on femoral overgrowth.