Modified Pauwels' intertrochanteric osteotomy in neglected femoral neck fractures in children: a report of 10 cases followed for a minimum of 5 years.

OBJECTIVES

To evaluate the role of a modified Pauwels' intertrochanteric osteotomy (MPIO) in neglected femoral neck fractures in children.

DESIGN

Prospective study with retrospective analysis.

SETTING

Tertiary care Postgraduate Institute of Medical Sciences.

PATIENTS

Ten children (8 males, 2 females) with an average age of 10.2 years with neglected femoral neck fractures were seen from 1990 to 1998. A femoral neck fracture was considered neglected when no proper medical treatment was instituted for at least 1 month following the fracture. Nonunion was accompanied by coxa vara and resorption of the femoral neck in 9 patients; a 10th patient had a neglected femoral neck fracture for 1 month without coxa vara. Three patients at time of presentation with Delbet Type II displaced fractures with associated nonunion and coxa vara (2 with Ratliff Type III and 1 with Type I) also had avascular necrosis using plain radiographic criteria of increased density.

INTERVENTION

Modified Pauwels' intertrochanteric osteotomy. The children were immobilized in a hip spica for 6-10 weeks postoperatively and weightbearing was started after hip spica removal.

MAIN OUTCOME MEASUREMENTS

Fracture healing, neck-shaft angle, avascular necrosis, and functional outcome.

RESULTS

Patients were followed for an average of 8.2 years (range 5-12 years). All patients had union of their fracture within an average of 16.6 weeks (12-20 weeks) and of the osteotomy site within 8.2 weeks (7-9 weeks). Radiologic signs of avascular necrosis disappeared completely in the 3 patients who presented with avascular necrosis. In 1 patient with a preoperatively viable femoral head, radiologic signs of Ratliff Type I avascular necrosis appeared between 60 and 98 weeks. This radiologic finding became normal again, indicating viability of the femoral head somewhere between 98 to 205 weeks of follow-up. Postoperatively, an average of 135-degree neck-shaft angle was achieved (range 125-160 degrees). The average preoperative neck-shaft angle was 104.4 degrees (range 92-120 degrees) and on the normal hip side it was 127.7 degrees (range 124-132 degrees). Significant improvement in the neck-shaft angle was seen compared with the preoperative angle (P < 0.001) and normal hip angle (P < 0.05). Coxa vara and signs of chondrolysis were not observed in any of the patients. Premature proximal femoral epiphyseal closure resulting in a 1-cm and a 1.5-cm leg-length discrepancy was seen in 2 patients as compared with their normal side. A mild Trendelenburg gait was observed in 1 patient (10%). Using Ratliff's criteria, 9 patients (90%) were graded as a good result and 1 patient (10%) was graded as a fair result. The osteotomy plate was removed in 1 patient (10%).

CONCLUSION

An MPIO creates a biomechanical environment conducive to healing of a neglected femoral neck nonunion in a child while simultaneously correcting an associated coxa vara. The procedure also seems to have a biological role in helping restore viability to a noncollapsed femoral head with avascular necrosis.