Biomechanical Evaluation of Internal Fixation of Pauwels Type III Femoral Neck Fractures: A Systematic Review of Various Fixation Methods

Abstract

Background The purpose of this systematic review was to investigate various fixation methods or implants used in the treatment of Pauwels type III femoral neck fractures. Methods PubMed Central, OVID Medline, Cochrane Collaboration Library, Web of Science, Embase, and AHRQ databases were searched to identify relevant studies published until August 2017 with English language restriction. Studies were selected on the basis of the following inclusion criteria: biomechanical study of Pauwels type III femoral neck fractures and the use of dynamic hip screw (DHS) or multiple screw fixation or other devices for fixation of the fracture. Results A total of 15 studies were included in the systematic review. Eight studies were conducted using cadavers, six studies using sawbones, and one using a finite element model. During the mechanical testing, each study measured mechanical stiffness, failure to cyclic loading, failure to vertical loading of each fixation device. DHS was included in 11 studies, multiple screw fixation in 10 studies, and other devices in six studies. Baitner et al. and Samsami et al. reported that the mechanical stiffness of DHS was superior to three inverted triangular screw fixation. Hawks et al. and Gumustas et al. reported that using a transverse calcar screw can withstand vertical loading better than three inverted triangular screw fixation. In addition, there were some studies where instruments such as Intertan nail, locking plate or other devices showed excellent biomechanical properties. Conclusions There are a variety of methods and instruments for fixation of the Pauwels type III fractures. However, it is difficult to conclude that any method is more desirable because there are advantages and disadvantages to each method. Therefore, we should pay attention to the implant choice and consider adequate weight bearing affecting the stiffness of the implant.

Fixation of femoral neck fractures with three cannulated screws: biomechanical changes at critical fracture angles

“…When these data are interpreted clinically, it is obvious that increasing the angle of fracture results in increased instability. In the Pauwels classification, fracture angles of more than 50 o are classified as Type 3 and these angles are associated with high instability and complication rates [3,8,20,21]. However, our study results show that notable differences occur across fracture angles ranging from 30 o to 50 o , whereas biomechanical differences occur less at angles of more than 50 o .…”

“…Based on the angle of the fracture line in the coronal plane, angles of up to 30 degrees are classified as type 1, angles between 30 degrees-50 degrees are classified as type 2, and angles higher than 50 degrees are classified as type 3 [7]. Several studies report that high fracture angles in the coronal plane increase the likelihood of failure after fixation with cannulated screws, thereby, resulting in increased rates of postoperative complications [8,9]. Despite many studies investigating this subject matter in the literature, more studies are needed to understand biomechanical changes and complications that may occur in association with different fracture configurations [10].…”

Tratamiento de las fracturas de cuello femoral con osteosíntesis. Diez claves para el éxito

“…En 2019, Cha y cols. 28 publican una revisión sistemática de la bibliografía sobre esta controversia. Evalúan 18 estudios y concluyen en que la mayoría compara resultados mecánicos y no clínicos, por lo que es imposible determinar qué opción de implante es mejor para cada situación.…”

Medial femoral plate with cannulated screw for Pauwels type III femoral neck fracture: A meta-analysis

“…Hollow nails and medial support plates are an emerging treatment method that can be used to treat Pauwels type III femoral neck fractures [13][14][15]. At present, a medial femoral neck support plate combined with hollow screw internal fixation is an emerging treatment of Pauwels type III femoral neck fracture in clinical practice [16,17]. However, whether it can accelerate fracture healing and reduce femoral head necrosis is still controversial.…”