CT evaluation of torsional malalignment after intertrochanteric fracture fixation.

INTRODUCTION Trochanteric fractures are commonly stabilized either by intramedullary nailing or plate and screw fixation after reduction on the orthopaedic surgical table under radiological guidance. HYPOTHESIS Closed trochanteric fracture anatomic reduction is difficult in the transversal plane. OBJECTIVES The objective of this prospective study was to assess the rotational malalignment induced after reduction and osteosynthesis of trochanteric fractures. PATIENTS AND METHODS Prospective study including 40 patients (mean age, 78 years; range, 51-90 years) operated for a trochanteric fracture between January 2007 and September 2008. Fourteen fractures were treated using DHS™ (Synthes™) plate and screw fixation and 26 with intramedullary nailing (trochanteric nail™, Stryker™). All these patients underwent postoperative CT of the pelvis during their hospitalization with measurement of anteversion of the operated and healthy femoral necks at the posterior condyles. The evaluation criterion was whether or not there was malalignment greater than 15° on the operated side compared to the healthy side. RESULTS The mean anteversion was 14.2° for the healthy side and 23° for the operated side. The mean rotational malalignment was 15.3°. Forty percent of the rotational malalignments were greater than 15°, with a majority of cases showing excess internal rotation (35%) of the distal fragment. CONCLUSION AND DISCUSSION The rate of internal rotational malalignment of the distal fragment greater than 15° was high (40% of this series). This should encourage surgeons to reduce the excess internal rotation that tends to be attributed to the distal fragment during preoperative reduction of these fractures. LEVEL OF EVIDENCE Level III. Prospective diagnostic study with no control group.