Effect of screw blade position on proximal femoral nail anti-rotation internal fixation for unstable intertrochanteric fractures in the elderly

Abstract

To investigate the effect of the screw blade position on the effectiveness of proximal femoral nail anti-rotation (PFNA) internal fixation for unstable intertrochanteric fractures in the elderly. A clinical data of 131 elderly patients with unstable intertrochanteric fractures who were treated with PFNA internal fixation between January 2010 and January 2017 was retrospectively analyzed. According to the anteroposterior X-ray films, the screw blades were placed in the middle of the femoral neck in 72 patients (group A) and at one-third of the femoral neck in 59 patients (group B). There was no significant difference between the two groups ( P>0.05) in the gender, age, bone density, classification of fractures, other medical diseases, and the time between injury and operation. Multiple treatment indexes were analyzed, including complications, hip Harris score, the healing status of fracture, tip-apex distance (TAD), and the height of the tail nail. All patients were followed up 11-14 months, with an average of 12.1 months. All incisions healed by first intention with no complications. All fractures healed and no significant difference in bone healing time between the two groups ( Z=-0.190, P=0.849). At 6 months after operation, TAD was (2.23±0.07) cm in group A and (2.85±0.12) cm in group B, showing significant difference ( t=-47.643, P=0.000); and the height of the tail nail was (1.72±0.14) cm in group A and (0.53±0.26) cm in group B, showing significant difference ( t=31.031, P=0.000). According to the Harris score, the hip functions were rated as excellent in 48 cases, good in 15 cases, and poor in 9 cases in group A, while as excellent in 38 cases, good in 16 cases, and poor in 5 cases in group B, with no significant difference between the two groups ( Z=-0.075, P=0.941). For the unstable intertrochanteric fracture in the elderly, the PFNA internal fixation with appropriated TAD and the screw blades placed in the middle or at one-third of the femoral neck can obtain good effectiveness.