Single or double distal locking in intramedullary nailing of tibial shaft fractures: a prospective randomized study.

Background: The number of distal locking screws may have an effect on union, complication rates and operation time. The purpose of this study was to determine the effect of one or two distal locking screws in unreamed intramedullary nailing of closed or grade 1 open, simple or wedge tibial shaft fractures on the incidence of malunion, delayed union, non-union, and screw failure.

Methods: Fifty-seven patients (39 male, 18 female; mean age 38.5+/-10.7 years) were randomized to two groups as either one or two distal locking screws and were evaluated prospectively for the incidences of malunion, delayed union, non-union, and screw failure. Twenty-nine patients were included in the two distal screws group and 28 patients in the single distal screw group. Groups were then subdivided to end fractures (proximal+distal end fractures) or mid-shaft fractures and reevaluated for the incidences of complications. Mann-Whitney U, chi-square and T tests were used for statistical analysis.

Results: Mean follow-up was 2.4 years (range, 1.5-4.7 years). There was no case of malunion in either group. The incidences of delayed union, non-union or screw failure were not different (p>0.05). However, complication rate for end fractures in the two screw group was higher than that in the one screw group (p:0.04).

Conclusion: For non-complex, closed or grade 1 open tibial shaft fractures, locking of an intramedullary nail with a single distal screw is safe, and may help to decrease operation time and radiation exposure.