Finite Element Analysis of Femoral Neck Fracture Treated with Bidirectional Compression-Limited Sliding Screw

Comparative Biomechanical Analysis of Anterior Process Locking Plate Alone versus Combined with Percutaneous Cannulated Screw Fixation for Sanders Type II Calcaneal Fractures: A Finite Element Study

BACKGROUND Calcaneal fractures are the most common tarsal bone fractures, and account for 75% of intra-articular fractures. The purpose of this study was to compare the biomechanical stability of the anterior process locking plate combined with the percutaneous cannulated screw fixation (screw group) versus the anterior process locking plate fixation alone (plate group) for the treatment of Sanders type II calcaneal fractures using finite element analysis to provide a theoretical basis for clinical work. MATERIAL AND METHODS We established a 3D model of Sanders type II calcaneal fracture; assigned material properties to the internal fixation systems; applied loads; set up analysis criteria; analyzed the displacement of the fracture, relative displacement, stress state of bone tissue, and internal fixation; and compared mechanical stability. RESULTS For Sanders type II A, II B, and II C calcaneal fractures, the degree of displacement and relative displacement of the fracture in the screw group was less than that of the plate group. For all subtypes of Sanders type II calcaneal fractures, the screw group had better mechanical stability than the plate group. CONCLUSIONS Both fixation methods (screw and plate group) were within a reasonable range for restoring the levelling effect of the joint surface and maintaining the strength of fixation, and both had good mechanical stability. Finite element analysis is a relatively reliable method, and biomechanics and clinical studies must further verify the experimental results.

A Comparative Study between Proximal Femoral Locking Plate and Multiple Cannulated Screws for Fixation of Femoral Neck Fractures in Young Adults

OBJECTIVE

To compare the clinical effect of proximal femoral locking plate (PFLP) versus multiple cancellous screw (MCS) for FNF.

METHODS

FNF patients were treated with the PFLP implant or multiple cancellous screws (MCSs). Patient has been followed up for at least 12 months after surgery nonunion, and the occurrence of complications, femoral neck shortening, fracture healing time, and Harris hip score were recorded and compared.

RESULTS

77 FNF patients were treated with the PFLP (36 patients) or MCS (41 patients). The sex, age, side of the injured limb, type of Garden fracture, time from injury to surgery, and fracture healing time of two groups patients were comparable. The operation time and intraoperative blood loss in the PFLP group were worse than those in the MCS group. Two patients with the PFLP (5%) and nine patients (21%) with the MCS experienced cut out of the lag screw or avascular necrosis of the femoral head or nonunion and received hip replacement. However, the number of fluoroscopies in the PFLP group was significantly lower than that in the MCS group. Additionally, the femoral neck shortening and Harris hip score were all strongly better in the PFLP group than in the MCS group.

CONCLUSIONS

Compared with the MCS, PFLP treatment for FNF in young adults can decrease the fluoroscopy times, improve hip functional recovery, and reduce the complications rate and femoral neck shortening.