Finite element analysis of the pelvis including gait muscle forces: an investigation into the effect of rami fractures on load transmission

Abstract

BackgroundThe objective of the study is to investigate the load transmission within the pelvic ring under physiological loading during gait and to correlate these results with clinical findings. In a second approach, we analysed how load distribution is altered by fractures of the anterior pelvic ring.MethodsMuscle forces and joint reaction forces are calculated by inverse dynamics and implemented in a finite element pelvis model including the joints.ResultsWith the intact configuration and according to the moment of the gait, left and right superior and inferior rami show the highest stresses of the model, corresponding to the typical location of an anterior pelvic ring fracture. A superior ramus fracture induces larger stresses to the lower ramus and a slight increase of stresses on the posterior structures. A total disruption of anterior rami redirects the loads to the back of the pelvis and introduces significantly higher stresses on the posterior structures.ConclusionsThis investigation enhances the understanding of the biomechanics of the pelvis and highlights the important role of the rami in load carrying and in maintaining integrity of the pelvic ring.

Fractures around the Pelvis, Pelvic Rim & Acetabulum in the Elderly: Report on 54 Cases

“…Other studies have confirmed the high prevalence of posterior pelvic ring disruption in association with a fracture of both branches of the pubic bone [7] [12].…”

“…In pelvic ring fractures, the posterior fracture of the sacral wing is often not seen on plain radiographs, making CT evaluation necessary for a complete diagnosis. Ricci and Gerich [7] showed through a theoretical analysis using an elaborated finite element model of a pelvis that the stresses at the sacral wing increase dramatically after interruption of the pubic rami. The work of Ricci and Gerich can explain why we often see fatigue fractures in the back of the pelvic ring together with fractures of the pubic area.…”

Modified pedicle screw-rod versus anterior subcutaneous internal pelvic fixation for unstable pelvic anterior ring fracture: A retrospective study and finite element analysis

“…In order to define the solid geometry of the pelvis, we constructed a model of the pelvis of a healthy 32-year-old male (height, 175 cm and weight, 73 kg) based on images from a CT scan. The material properties of the model were obtained from previous studies ( Table 3) [1]. A 2-cm gap was created at the right superior and inferior rami to simulate injury using Geomagic Studio software (3D Systems Inc, Rock Hill, SC, USA).…”

“…Anterior pelvic structures are more fragile and prone to fracture than dorsal parts as they bear higher loads [1]. Clinically, high-energy pelvic ring fractures leading to decreased functionality account for approximately 1.5-3.9% of all fractures [2].…”

Conventional and Arthrographic Magnetic Resonance Techniques for Hip Evaluation: What the Radiologist Should Know

“…These complex bony and soft tissue structures act together to transmit forces from the lumbar spine to the lower limbs and enable gait and complex lower limb movements that combine weightbearing and movement vector forces. [1][2][3] Due to the close relation of bony and soft tissue structures, symptoms around the pelvis and hip are frequently unspecific, and patients often have coexistent lesions. Thus unless the clinician asks a very specific question, a general radiographic view of the pelvis should first be obtained.…”