Significance of preoperative planning for prophylactic augmentation of osteoporotic hip: A computational modeling study

Amirhossein Farvardin; Ehsan Basafa; Mahsan Bakhtiarinejad; Mehran Armand

doi:10.1016/j.jbiomech.2019.07.012

Significance of preoperative planning for prophylactic augmentation of osteoporotic hip: A computational modeling study

J Biomech. 2019 Sep 20:94:75-81. doi: 10.1016/j.jbiomech.2019.07.012. Epub 2019 Jul 19.

Authors

Amirhossein Farvardin¹, Ehsan Basafa², Mahsan Bakhtiarinejad³, Mehran Armand⁴

Affiliations

¹ Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; Laboratory for Computational Sensing and Robotics, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA. Electronic address: afarvar1@jhu.edu.
² Auris Health, Inc., 150 Shoreline Dr, Redwood City, CA 94065, USA.
³ Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; Laboratory for Computational Sensing and Robotics, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA.
⁴ Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; Laboratory for Computational Sensing and Robotics, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, USA; Department of Orthopaedic Surgery, Johns Hopkins University, 601 N. Caroline Street, Baltimore, MD 21287, USA.

Abstract

A potential effective treatment for prevention of osteoporotic hip fractures is augmentation of the mechanical properties of the femur by injecting it with bone cement. This therapy, however, is only in research stage and can benefit substantially from computational simulations to optimize the pattern of cement injection. Some studies have considered a patient-specific planning paradigm for Osteoporotic Hip Augmentation (OHA). Despite their biomechanical advantages, customized plans require advanced surgical systems for implementation. Other studies, therefore, have suggested a more generalized injection strategy. The goal of this study is to investigate as to whether the additional computational overhead of the patient-specific planning can significantly improve the bone strength as compared to the generalized injection strategies attempted in the literature. For this purpose, numerical models were developed from high resolution CT images (n = 4). Through finite element analysis and hydrodynamic simulations, we compared the biomechanical efficiency of the customized cement-based augmentation along with three generalized injection strategies developed previously. Two series of simulations were studied, one with homogeneous and one with inhomogeneous material properties for the osteoporotic bone. The customized cement-based augmentation inhomogeneous models showed that injection of only 10 ml of bone cement can significantly increase the yield load (79.6%, P < 0.01) and yield energy (199%, P < 0.01) of an osteoporotic femur. This increase is significantly higher than those of the generalized injections proposed previously (23.8% on average). Our findings suggest that OHA can significantly benefit from a patient-specific plan that determines the pattern and volume of the injected cement.

Keywords: Finite element analysis; Osteoporotic hip augmentation; PMMA cement; Surgical planning.

MeSH terms

Biomechanical Phenomena
Bone Cements / therapeutic use*
Bone and Bones
Female
Femur / surgery
Finite Element Analysis
Hip Fractures / prevention & control*
Hip Joint / diagnostic imaging
Humans
Male
Models, Theoretical
Osteoporotic Fractures / prevention & control*
Patient-Specific Modeling*
Polymethyl Methacrylate / administration & dosage*
Tomography, X-Ray Computed

Substances

Bone Cements
Polymethyl Methacrylate

Abstract

MeSH terms

Substances

Grants and funding