“…On the basis of a review of the literature, we hypothesized that the following variables might be associated with fixation failure: age, 31 gender, 31 fracture type (displaced/undisplaced), 20,33,34,38 fracture comminution, 33,38 total number of screws, [7][8][9]22 number of screws with a short thread (16 mm) versus number of screws with a long thread (32 mm), absence of a washer, screw configuration (triangle, inverted triangle, or vertical alignment), 9,10,14,23,24 reduction quality 9-12,15-21 (Garden's Alignment Index), distance of the most inferior screw to the inferior neck, 9,25,26 screw alignment (parallel, convergent, divergent on anteroposterior and lateral radiographs), [9][10][11][12][13][14] mean angle of screw entry (relative to the lateral cortex of the shaft), and distance of the most inferior screw to the lesser trochanter. In addition, we recorded the sum of the distances of the tip of each screw and the apex of the femoral head on anteroposterior and lateral radiographs (tip-apex distance [TAD] sum) analogous to the tip-apex distance of Baumgaertner et al as a predictor of failure for placement of dynamic condylar screws.…”