Dynamic hip screw versus cannulated cancellous screws fixation for osteosynthesis of femoral neck fractures in adults: a retrospective comparative study.

OBJECTIVE: Femoral neck fractures in young adults are relatively rare and often present challenges in achieving optimal treatment outcomes. Several surgical techniques have been proposed for managing these fractures. This study aims to compare the clinical and radiological outcomes of femoral neck fractures treated with either a dynamic hip screw combined with an anti-rotation screw (DHS/AS) or cannulated cancellous screws (CCS). METHOD: This retrospective comparative study included 60 patients with a minimum follow-up period of one year. Key factors assessed included fracture union, complications such as avascular necrosis (AVN), non-union, varus collapse, femoral neck shortening, screw backout, and functional outcomes measured by the Harris Hip Score (HHS). RESULTS: Sixty patients with a minimum follow-up of 12 months were analyzed, with 30 patients each in the DHS/AS and CCS groups. Fracture union was achieved in 87.0% of patients in the DHS/AS group and 83.3% in the CCS group (P = 0.25), with comparable mean time to union (5.1 ± 0.8 vs. 4.9 ± 0.7 months; P = 0.61). Nonunion occurred in 12.9% and 16.6% of patients, respectively (P = 0.25). Femoral neck shortening was significantly lower in the DHS/AS group (3.8 ± 2.0 mm) compared with the CCS group (10.5 ± 6.0 mm; P = 0.01). Similarly, screw backout was significantly less with DHS/AS (1.8 ± 2.2 mm vs. 9.1 ± 3.4 mm; P = 0.002). Mean varus collapse was lower in the DHS/AS group (1.6° ± 1.5° vs. 4.8° ± 5.9°), although the difference was not statistically significant (P = 0.15). Avascular necrosis developed in three patients in the CCS group and in none of the DHS/AS group. Functional outcome was significantly better following DHS/AS fixation, with a higher mean Harris Hip Score (89.5 ± 7.4 vs. 79.3 ± 10.1; P = 0.02). CONCLUSION: Compared to multiple cannulated screws, fixation with DHS/AS provides superior clinical outcomes and is a more effective approach for treating femoral neck fractures.