[Leg length inequality after childhood femoral fractures--permanent or temporary phenomenon?].

Leg length inequality is the most common complication reported after femoral shaft fractures in childhood. Most authors agree that significant overgrowth occurs in the first two years after injury and will not be further corrected. We reviewed 221 patients (166 boys, 44 girls) with a fracture of the femoral shaft. The mean age at the time of fracture was 6.5 years (range 11 months to 12 years); 123 patients were treated conservatively, 96 by skin traction, 11 by skeletal traction, and 16 by immediate cast bracing. In 98 patients the fracture was stabilized by osteosynthesis. In 5 fractures located in the distal third of the femur we used crossed Kirschner wires. Fifty-nine patients were treated by intramedullary nailing, without problems regarding trochanteric apophyseal arrest or alteration in the collum angle. Thirty-four patients were treated by plate fixation, this being associated with high rates (9%) of implant-breakage. A total of 127 patients were interviewed and examined; they were skeletally mature at the time of reexamination. A leg-length discrepancy was found in 45 patients. Shortening from 10 to 30 mm (mean 14.3 mm) occurred in 7 patients; 38 patients had lengthening from 10 to 25 mm (mean 14.1 mm). Overgrowth significantly depended on the age at trauma (4-9 years; P = 0.04), number of repositions (2 or more; P = 0.0005) and degree of axial deviation (> 10 degrees; P = 0.04). Delayed surgical treatment (> 48 h; P = 0.0035), especially plate fixation (P = 0.0003) induced overgrowth as well. Forty-six patients had previously been reevaluated 12 years before (1981). In 12 patients 13 years or older at the time of the first review, no change in leg-length difference occurred. At the first review 34 patients were younger than 13 years. Eight of them had no leg-length discrepancy. In 16 patients the growth rate of the affected femur decreased, so that leg-length discrepancy diminished after the 2-year period posttraumatically in a range from 5 to 15 mm. Overgrowth of the femur continued in 7 cases ranging from 5 to 10 mm. No change occurred in 3 patients. Thus, there is a further change in length inequality more than 2 years post-traumatically.