Influence of titanium elastic nail pre-contouring on fracture reduction of paediatric diaphyseal forearm fractures

Purpose: To radiologically investigate in a human cadaveric model the effect of nail shape on fracture reduction in pediatric transverse diaphyseal fractures of the radius and ulna using straight nails, pre-contoured, or a combination of both. Methods: Twelve human cadaveric forearms from six adult donors were used and standardized AO PCCF 22-D/4.1 transverse diaphyseal fractures of the radius and ulna were created. Titanium elastic nails (TENs) were inserted retrograde in the radius and anterograde in the ulna creating 3 groups with either 2 straight TENs (Group1), 1 straight and 1 curved TEN (Group2), or 2 curved TEN (Group3). Anteroposterior radiographs of each intact and instrumented specimen in each group were taken in supination. Parameters of interest included total bone length and maximal radial bow (MRB) Results: After TEN instrumentation MRB decreased significantly in Group1 and increased significantly in Group2 (p≤0.003), however, it was without a significant change in Group3 (p=0.113). In addition, MRB in instrumented state was significantly lower in Group1 versus both Group2 and Group3 (p ≤0.005). Both total bone lengths remained nearly unchanged after instrumentation across the groups (p≥0.608). Conclusion: The use of two curved TENs resulted in smallest deviation from the natural anatomical alignment after reduction of both-bone pediatric forearm fractures. Fixation of these fractures with one straight and one curved TEN leads to overcorrection of the radial bow whereas utilization of two straight TENs leads to the most inferior results, with reduction of the radial bow and anticipated loss of range of motion in the forearm.