Use of flexible intramedullary nails in pediatric femur fractures.

Flexible intramedullary nails are now routinely used for stabilization of pediatric femur fractures. Few data are available regarding patients' postoperative range of motion, weight-bearing status, activity levels, use of immobilization, and radiographic leg length discrepancy measured via routine scanograms. Patients who underwent placement of flexible intramedullary nails for a pediatric femur fracture at a single institution from 1998 to 2003 were identified retrospectively. Ninety-one patients were identified with 94 femur fractures. The complication rate was 17% for the 94 fractures, with 8 patients requiring an unplanned return to surgery. The complication rate was significantly higher for patients aged 10 years or older (34%) as compared with that for younger patients (9%). Average time to full weight bearing was 10 weeks, time to radiographic union averaged 10.7 weeks, and time to return to preoperative level of activity averaged 4.9 months. Immediate postoperative weight bearing status was nonweight bearing in 57%. Immobilization or support was used postoperatively in 60% of the patients. Postoperatively, patients had minimal loss of range of motion in hip internal and external rotation and knee extension. Hip and knee flexion rapidly improved postoperatively with an average loss of hip flexion of 0 degree by 3 months and an average loss of knee flexion of 4 degrees by 6 months. Postoperatively, limb length discrepancy was greater than 1 cm in 7 patients at 6 months, 11 patients at 12 months, 3 patients at 18 months, and 2 patients at 2 years. Two patients had persistent limb length discrepancy of greater than 2 cm, but only one patient required an epiphysiodesis for his limb length inequality. Although the end results are favorable, complications are relatively frequent, particularly in older children.