Clinical analysis of internal fixation femoral neck fractures with two or three cannulated screws

Abstract

Introduction/Objective. Angular stability and dynamic fixation are key factors to successful healing of femoral neck fractures. The objective was to evaluate the efficacy of internal fixation of femoral neck fractures with two parallel self-tapping antirotation screws (SAF) compared to standard, three cannulated cancellous screws (CCS) fixation. Methods. In total 100 fractures were retrospectively analyzed, divided in two groups in which two SAF screws were used in parallel (n = 50) or three standard screws in an inverted triangle configuration (n = 50). The groups were compared with operation time, time of consolidation, femoral neck shortening, Harris hip score and reoperation rates. Results. SAF parallel fixation group of patients achieved consolidation rate of 86% compared to 74% in CCS fixation group, without statistically significant difference between the examined groups (p > 0,05). Dynamization of implants was significantly positively correlated with the fracture healing time in both examined groups (SAF: r = 0.324, p = 0.025; CCS: r = 0.572, p = 0.001), with significantly shorter healing time in SAF patients – on average 15 weeks (15.02 ± 1.44) in relation to the CCS group of patients – 19 weeks (19.81 ± 2.94) (χ2/z = 7.048, p < 0.001). There was no statistically significant difference in the Harris hip score and reoperation rate among the study groups (χ2 = 2.44, p = 0.487; χ2 = 0.500, p = 0.696). Conclusion. Our results suggested that dual parallel fixation is simpler, less invasive and it demands less performance time. It is not inferior to fixation with three screws, from the point of biomechanics, possible complications, healing and functional recovery.

Keywords

• femoral neck fractures
• bone union
• internal fixation