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Fracture strength of the proximal femur injected with a calcium sulfate/hydroxyapatite bone substitute

Kok, Joeri LU ; Širka, Aurimas; Grassi, Lorenzo LU ; Raina, Deepak Bushan LU ; Tarasevičius, Šarūnas LU ; Tägil, Magnus LU ; Lidgren, Lars LU and Isaksson, Hanna LU (2019) In Clinical Biomechanics 63. p.172-178
Abstract

Background: Available interventions for preventing fragility hip fractures show limited efficacy. Injection of a biomaterial as bone substitute could increase the fracture strength of the hip. This study aimed to show the feasibility of injecting a calcium sulfate/hydroxyapatite based biomaterial in the femoral neck and to calculate the consequent change in strength using the finite element method. Methods: Five patients were injected with 10 ml calcium sulfate/hydroxyapatite in their femoral neck. Quantitative CT scans were taken before and after injection. Five additional patients with fragility hip fractures were also scanned and the images from the non-fractured contralateral sides were used. Finite element models were created for... (More)

Background: Available interventions for preventing fragility hip fractures show limited efficacy. Injection of a biomaterial as bone substitute could increase the fracture strength of the hip. This study aimed to show the feasibility of injecting a calcium sulfate/hydroxyapatite based biomaterial in the femoral neck and to calculate the consequent change in strength using the finite element method. Methods: Five patients were injected with 10 ml calcium sulfate/hydroxyapatite in their femoral neck. Quantitative CT scans were taken before and after injection. Five additional patients with fragility hip fractures were also scanned and the images from the non-fractured contralateral sides were used. Finite element models were created for all proximal femora with and without injection and the models were tested under stance and sideways fall loading until fracture. The change in fracture strength caused by the injection was calculated. Additionally, perturbations in volume, location, and stiffness of the injected material were created to investigate their contribution to the fracture strength increase. Findings: The 10 ml injection succeeded in all patients. Baseline simulations showed theoretical fracture strength increases of 0–9%. Volume increase, change in location and increase in stiffness of the material led to increases in fracture strength of 1–27%, −8-26% and 0–17%, respectively. Altering the location of the injection to a more lateral position and increasing the stiffness of the material led to increases in fracture strength of up to 42%. Interpretation: This study shows that an injection of calcium sulfate/hydroxyapatite is feasible and can theoretically increase the hip's fracture strength.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bone strength, Ceramics, Finite element analysis, Hip fracture, Osteoporosis, Prophylactic injection
in
Clinical Biomechanics
volume
63
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85063091248
ISSN
0268-0033
DOI
10.1016/j.clinbiomech.2019.03.008
language
English
LU publication?
yes
id
2754adb8-71da-492d-8549-aabed46ea0ec
date added to LUP
2019-03-28 12:22:21
date last changed
2019-04-23 04:47:26
@article{2754adb8-71da-492d-8549-aabed46ea0ec,
  abstract     = {<p>Background: Available interventions for preventing fragility hip fractures show limited efficacy. Injection of a biomaterial as bone substitute could increase the fracture strength of the hip. This study aimed to show the feasibility of injecting a calcium sulfate/hydroxyapatite based biomaterial in the femoral neck and to calculate the consequent change in strength using the finite element method. Methods: Five patients were injected with 10 ml calcium sulfate/hydroxyapatite in their femoral neck. Quantitative CT scans were taken before and after injection. Five additional patients with fragility hip fractures were also scanned and the images from the non-fractured contralateral sides were used. Finite element models were created for all proximal femora with and without injection and the models were tested under stance and sideways fall loading until fracture. The change in fracture strength caused by the injection was calculated. Additionally, perturbations in volume, location, and stiffness of the injected material were created to investigate their contribution to the fracture strength increase. Findings: The 10 ml injection succeeded in all patients. Baseline simulations showed theoretical fracture strength increases of 0–9%. Volume increase, change in location and increase in stiffness of the material led to increases in fracture strength of 1–27%, −8-26% and 0–17%, respectively. Altering the location of the injection to a more lateral position and increasing the stiffness of the material led to increases in fracture strength of up to 42%. Interpretation: This study shows that an injection of calcium sulfate/hydroxyapatite is feasible and can theoretically increase the hip's fracture strength.</p>},
  author       = {Kok, Joeri and Širka, Aurimas and Grassi, Lorenzo and Raina, Deepak Bushan and Tarasevičius, Šarūnas and Tägil, Magnus and Lidgren, Lars and Isaksson, Hanna},
  issn         = {0268-0033},
  keyword      = {Bone strength,Ceramics,Finite element analysis,Hip fracture,Osteoporosis,Prophylactic injection},
  language     = {eng},
  pages        = {172--178},
  publisher    = {Elsevier},
  series       = {Clinical Biomechanics},
  title        = {Fracture strength of the proximal femur injected with a calcium sulfate/hydroxyapatite bone substitute},
  url          = {http://dx.doi.org/10.1016/j.clinbiomech.2019.03.008},
  volume       = {63},
  year         = {2019},
}