Background: Hip screw cutout is among the most common causes of intertrochanteric fracture fixation failure using dynamic hip screws (DHS). This study aimed to evaluate the effect of using an additional anti-rotation screw on hip screw migration or cutout in intertrochanteric fracture fixation.
Materials and methods: We screened 488 patients with unilateral fragile intertrochanteric fractures treated with DHS between January 2001 and March 2016. The inclusion criteria were as follows: (1) age ≥ 50 years; (2) low-energy injury; (3) follow-up of at least 6 months; and (4) short barrel plate used in the operation. The exclusion criteria were as follows: (1) combination with other fracture; or (2) pathological fracture. Subsequently, 166 patients were enrolled; of them, 128 underwent surgery using DHS with an additional screw (Group 1) and 38 patients underwent surgery without an additional screw (Group 2). We compared the postoperative results and clinical outcomes while focusing on screw migration and cutout. Furthermore, we investigated the risk factors for lag screw migration.
Results: Bone union was achieved in 160 patients (96.4%) without secondary intervention. Two patients (1.6%) in Group 1 and 1 (2.6%) in Group 2 developed screw cutout, while 18 (14.1%) in Group 1 and 12 (31.6%) in Group 2 developed screw migration. Thus, Group 2 demonstrated a higher screw migration rate. Multiple logistic regression analysis revealed that the additional anti-rotation screw was the most important factor in preventing screw migration (P = 0.019).
Conclusion: The additional anti-rotation screw reduced the lag screw migration rate following DHS surgery for intertrochanteric fractures.
Level of evidence: Level IV, retrospective series.
Keywords: Anti-rotation screw; Cutout; Dynamic hip screw; Intertrochanteric fracture; Mechanical failure.