Biomechanical and Finite-Element Analysis of Femoral Pin-Site Fractures Following Navigation-Assisted Total Knee Arthroplasty

Abstract

Background:Femoral pin-site fracture is one of the most serious complications of navigation-assisted total knee arthroplasty (TKA). Its occurrence is associated with the loss of biomechanical strength caused by intraoperative femoral drilling. This study aimed to investigate the drilling location as a risk factor for pin-site fracture.Methods:A biomechanical analysis using rabbit femora was performed to determine the effects of drilling eccentricity and height. Torsional, 3-point bending, and axial compression tests were performed to evaluate biomechanical parameters, including failure strength, failure displacement, and stiffness. Fracture type and the presence of comminution were noted and analyzed. Finite-element analysis (FEA) was utilized to assess the stress distribution and deformation. The cumulative sum (CUSUM) method was applied to define the safe range for drilling eccentricity.Results:Drilling operations were accurately implemented. Biomechanical tests confirmed that severely eccentric drilling significantly reduced the biomechanical strength of the femur, especially in torsion. FEA results provided evidence of threatening stress concentration in severely eccentric drilling. The overall safe range of eccentricity relative to the center of the femur was found to be between 50% of the radius in the anterolateral direction and 70% of the radius in the posteromedial direction.Conclusions:Severely eccentric drilling significantly increased the risk of femoral pin-site fracture, especially under torsional stress. Femoral drilling should be performed in the safe zone that was identified.

Risk of internal fixation treatment in intertrochanteric fracture based on different lateral femoral wall thickness: finite element analysis

“…Although the von Mises stress for each model remains below the yield stress, increasing the maximum stress increases the risk of internal fixation fatigue failure. And the present model has been validated with the previous literatures with same material properties and boundary and loading conditions and the results of the present model were well collaborated with the previous one we use in other study [ 26 ]. Therefore, it is evident that PFNA has better stability and a lower risk of internal fixation fracture and failure than DHS.…”

Robotic-assisted patellofemoral arthroplasty provides excellent implant survivorship and high patient satisfaction at mid-term follow-up

“…1 ). The first, located approximately a hand span (four fingers) superior to the patella, faced to the center of the femur [ 29 ], while the second was fixed parallel to the first through a dedicated guide. Virtual model of the patient’s distal femur and trochlea was generated intraoperatively digitizing anatomical landmarks with an infrared camera-guided point probe without any pre-operative MRI or CT imaging.…”

Model Properties and Clinical Application in the Finite Element Analysis of Knee Joint: A Review

“…Sun et al combined the results of finite element analysis with biomechanical experiments to propose a safety zone for drilling. 117 Shinji et al studied the risk of medial tibial condyle fracture in UKA, which increased with tibial valgus and posterior tibial sagittal incision enlargement. 118 Stoddart et al suggested that bi-UKA had a similar risk of tibial eminence avulsion fracture to UKA, with a higher risk of fracture when tibial bone density was lower.…”

“…Sun et al . combined the results of finite element analysis with biomechanical experiments to propose a safety zone for drilling 117 . Shinji et al .…”