A Biomechanical Investigation of the Surface Stress of a Synthetic Femur Using Infrared Thermography Validated by Strain Gauge Measurements

As the North American population ages, there will be a massive increase in musculoskeletal impairments because these problems are most common in the elderly. A very common condition is osteoporosis, which can result in fractures. Therefore, the need for improved orthopaedic fracture repair implants is vital. Currently, the two main approaches in studying orthopaedic implants are strain gauge measurements and finite element modelling. This study introduces and validates a relatively new, non-destructive approach in analysing stress patterns in a biomechanics application. Lock-in infrared (IR) thermography calibrated with strain gauges was used to investigate the stress and strain patterns of a synthetic femur under dynamic loading. The femur was instrumented with strain gauges and tested using axial average forces of 1500N, 1800N, and 2100N at an adduction angle of 7 degrees to simulate the single-legged stance phase of walking. Three dimensional surface stress maps were obtained using an IR thermography camera. Results showed a good agreement of IR thermography versus strain gauge data with a Pearson correlation of R² = 0.99 and a slope ranging from 0.99 to 1.08, based on thermoelastic coefficient (K_m) ranging from 1.067 x 10⁻⁵ /MPa to 1.16 x 10⁻⁵/MPa, for the line of best fit. IR thermography detected bone peak stresses on the superior-posterior side of the femoral neck of 91.2MPa (at 1500 N), 96.0Mpa (at 1800 N), and 103.5MPa (at 2100 N). There was strong correlation between IR measured stresses and force along the anterior (R² = 0.87 to 0.99), posterior (R² = 0.81 to 0.99) and lateral (R² = 0.89 to 0.99) surface. This is the first study to provide an experimentally validated three dimensional stress map of a synthetic femur using IR thermography

Year	Entry
2001	Bergmann G, Deuretzbacher G, Heller M, Graichen F, Rohlmann A, Strauss J, Duda GN. Hip contact forces and gait patterns from routine activities. J Biomech. July 2001;34(7):859-871.
1983	Brown TD, Shaw DT. In vitro contact stress distributions in the natural human hip. J Biomech. 1983;16(6):373-384.
1978	Crowninshield RD, Johnston RC, Andrews JG, Brand RA. A biomechanical investigation of the human hip. J Biomech. 1978;11(1-2):75-85.
1986	Hodge WA, Fijan RS, Carlson KL, Burgess RG, Harris WH, Mann RW. Contact pressures in the human hip joint measured in vivo. Proc Natl Acad Sci USA. May 1986;83(9):2879-2883.
2003	Anderson FC, Pandy MG. Individual muscle contributions to support in normal walking. Gait Post. April 2003;17(2):159-169.
1988	Fondrk M, Bahniuk E, Davy DT, Michaels C. Some viscoplastic characteristics of bovine and human cortical bone. J Biomech. 1988;21(8):623-630.
1972	Brekelmans WAM, Poort HW, Slooff TJJH. A new method to analyse the mechanical behaviour of skeletal parts. Acta Orthop Scand. 1972;43(5):301-317.
1979	Lakes RS, Katz JL, Sternstein SS. Viscoelastic properties of wet cortical bone, I: torsional and biaxial studies. J Biomech. 1979;12(9):657-678.
1984	Röhrle H, Scholten R, Sigolotto C, Sollbach W, Kellner H. Joint forces in the human pelvis-leg skeleton during walking. J Biomech. 1984;17(6):409-424.
1983	Rohlmann A, Mössner U, Bergmann G, Kölbel R. Finite-element-analysis and experimental investigation in a femur with hip endoprosthesis. J Biomech. 1983;16(9):727-742.
1971	Kempson GE, Spivey CJ, Swanson SAV, Freeman MAR. Patterns of cartilage stiffness on normal and degenerate human femoral heads. J Biomech. December 1971;4(6):597-609.
1987	Roesler H. The history of some fundamental concepts in bone biomechanics. J Biomech. 1987;20(11-12):1025-1034.
2008	Verhulp E, van Rietbergen B, Huiskes R. Load distribution in the healthy and osteoporotic human proximal femur during a fall to the side. Bone. January 2008;42(1):30-35.
1983	Martens M, Van Audekercke R, Delport P, De Meester P, Mulier JC. The mechanical characteristics of cancellous bone at the upper femoral region. J Biomech. 1983;16(12):971-983.
1964	McElhaney J, Fogle J, Byars E, Weaver G. Effect of embalming on the mechanical properties of beef bone. J Appl Physiol. November 1964;19(6):1234-1236.
1975	Lanyon LE, Hampson WGJ, Goodship AE, Shah JS. Bone deformation recorded in vivo from strain gauges attached to the human tibial shaft. Acta Orthop Scand. 1975;46(2):256-268.
2001	Heiner AD, Brown TD. Structural properties of a new design of composite replicate femurs and tibias. J Biomech. January 2001;34(6):773-781.
2007	Cristofolini L, Juszczyk M, Martelli S, Taddei F, Viceconti M. In vitro replication of spontaneous fractures of the proximal human femur. J Biomech. 2007;40(13):2837-2845.
1989	Hodge WA, Carlson KL, Fijan RS, Burgess RG, Riley PO, Harris WH, Mann RW. Contact pressures from an instrumented hip endoprosthesis. J Bone Joint Surg. October 1989;71A(9):1378-1386.
2009	Cristofolini L, Juszczyk M, Taddei F, Viceconti M. Strain distribution in the proximal human femoral metaphysis. Proc Inst Mech Eng Part H-J Eng Med. April 2009;2223(3):273-288.
1988	Davy DT, Kotzar GM, Brown RH, Heiple KG, Goldberg VM, Heiple KG Jr, Berilla J, Burstein AH. Telemetric force measurements across the hip after total arthroplasty. J Bone Joint Surg. January 1988;70A(1):45-50.
1995	van Rietbergen B, Weinans H, Huiskes R, Odgaard A. A new method to determine trabecular bone elastic properties and loading using micromechanical finite-element models. J Biomech. January 1995;28(1):69-81.
1998	Duda GN, Heller M, Albinger J, Schulz O, Schneider E, Claes L. Influence of muscle forces on femoral strain distribution. J Biomech. September 1998;31(9):841-846.
1967	Paul JP. Forces transmitted by joints in the human body. Proc Inst Mech Eng. 1967;181(pt 3J):8-15.
1996	Cristofolini L, Viceconti M, Cappello A, Toni A. Mechanical validation of whole bone composite femur models. J Biomech. April 1996;29(4):525-535.
2001	Yamashita J, Furman BR, Rawls HR, Wang X, Agrawal CM. The use of dynamic mechanical analysis to assess the viscoelastic properties of human cortical bone. J Biomed Mater Res. 2001;B58(1):47-53.
1986	Martens M, van Audekercke R, de Meester P, Mulier JC. Mechanical behaviour of femoral bones in bending loading. J Biomech. 1986;19(6):443-454.
1981	Huiskes R, Janssen JD, Slooff TJ. A detailed comparison of experimental and theoretical stress-analyses of a human femur. In: Cowin SC, ed. Mechanical Properties of Bone. The Joint ASME-ASCE Applied Mechnics, Fluids Engineering and Bioengineering Conference; June 22-24, 1981; Boulder, CO. New York, NY: American Society of Mechical Engineers; 1981:211-234.
1980	Martens M, van Audekercke R, de Meester P, Mulier JC. The mechanical characteristics of the long bones of the lower extremity in torsional loading. J Biomech. 1980;13(8):667-676.
1983	Huiskes R, Chao EYS. A survey of finite element analysis in orthopedic biomechanics: the first decade. J Biomech. 1983;16(6):385-409.
2007	Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg. April 2007;89A(4):780-785.
1993	Bergmann G, Graichen F, Rohlmann A. Hip joint loading during walking and running, measured in two patients. J Biomech. August 1993;26(8):969-990.
1985	Cheal EJ, Hayes WC, Lee CH, Snyder BD, Miller J. Stress analysis of a condylar knee tibial component: influence of metaphyseal shell properties and cement injection depth. J Orthop Res. 1985;3(4):424-434.

Year

Entry

2001

Bergmann G, Deuretzbacher G, Heller M, Graichen F, Rohlmann A, Strauss J, Duda GN. Hip contact forces and gait patterns from routine activities. J Biomech. July 2001;34(7):859-871.

1983

Brown TD, Shaw DT. In vitro contact stress distributions in the natural human hip. J Biomech. 1983;16(6):373-384.

1978

Crowninshield RD, Johnston RC, Andrews JG, Brand RA. A biomechanical investigation of the human hip. J Biomech. 1978;11(1-2):75-85.

1986

Hodge WA, Fijan RS, Carlson KL, Burgess RG, Harris WH, Mann RW. Contact pressures in the human hip joint measured in vivo. Proc Natl Acad Sci USA. May 1986;83(9):2879-2883.

2003

Anderson FC, Pandy MG. Individual muscle contributions to support in normal walking. Gait Post. April 2003;17(2):159-169.

1988

Fondrk M, Bahniuk E, Davy DT, Michaels C. Some viscoplastic characteristics of bovine and human cortical bone. J Biomech. 1988;21(8):623-630.

1972

Brekelmans WAM, Poort HW, Slooff TJJH. A new method to analyse the mechanical behaviour of skeletal parts. Acta Orthop Scand. 1972;43(5):301-317.

1979

Lakes RS, Katz JL, Sternstein SS. Viscoelastic properties of wet cortical bone, I: torsional and biaxial studies. J Biomech. 1979;12(9):657-678.

1984

Röhrle H, Scholten R, Sigolotto C, Sollbach W, Kellner H. Joint forces in the human pelvis-leg skeleton during walking. J Biomech. 1984;17(6):409-424.

1983

Rohlmann A, Mössner U, Bergmann G, Kölbel R. Finite-element-analysis and experimental investigation in a femur with hip endoprosthesis. J Biomech. 1983;16(9):727-742.

1971

Kempson GE, Spivey CJ, Swanson SAV, Freeman MAR. Patterns of cartilage stiffness on normal and degenerate human femoral heads. J Biomech. December 1971;4(6):597-609.

1987

Roesler H. The history of some fundamental concepts in bone biomechanics. J Biomech. 1987;20(11-12):1025-1034.

2008

Verhulp E, van Rietbergen B, Huiskes R. Load distribution in the healthy and osteoporotic human proximal femur during a fall to the side. Bone. January 2008;42(1):30-35.

1983

Martens M, Van Audekercke R, Delport P, De Meester P, Mulier JC. The mechanical characteristics of cancellous bone at the upper femoral region. J Biomech. 1983;16(12):971-983.

1964

McElhaney J, Fogle J, Byars E, Weaver G. Effect of embalming on the mechanical properties of beef bone. J Appl Physiol. November 1964;19(6):1234-1236.

1975

Lanyon LE, Hampson WGJ, Goodship AE, Shah JS. Bone deformation recorded in vivo from strain gauges attached to the human tibial shaft. Acta Orthop Scand. 1975;46(2):256-268.

2001

Heiner AD, Brown TD. Structural properties of a new design of composite replicate femurs and tibias. J Biomech. January 2001;34(6):773-781.

2007

Cristofolini L, Juszczyk M, Martelli S, Taddei F, Viceconti M. In vitro replication of spontaneous fractures of the proximal human femur. J Biomech. 2007;40(13):2837-2845.

1989

Hodge WA, Carlson KL, Fijan RS, Burgess RG, Riley PO, Harris WH, Mann RW. Contact pressures from an instrumented hip endoprosthesis. J Bone Joint Surg. October 1989;71A(9):1378-1386.

2009

Cristofolini L, Juszczyk M, Taddei F, Viceconti M. Strain distribution in the proximal human femoral metaphysis. Proc Inst Mech Eng Part H-J Eng Med. April 2009;2223(3):273-288.

1988

Davy DT, Kotzar GM, Brown RH, Heiple KG, Goldberg VM, Heiple KG Jr, Berilla J, Burstein AH. Telemetric force measurements across the hip after total arthroplasty. J Bone Joint Surg. January 1988;70A(1):45-50.

1995

van Rietbergen B, Weinans H, Huiskes R, Odgaard A. A new method to determine trabecular bone elastic properties and loading using micromechanical finite-element models. J Biomech. January 1995;28(1):69-81.

1998

Duda GN, Heller M, Albinger J, Schulz O, Schneider E, Claes L. Influence of muscle forces on femoral strain distribution. J Biomech. September 1998;31(9):841-846.

1967

Paul JP. Forces transmitted by joints in the human body. Proc Inst Mech Eng. 1967;181(pt 3J):8-15.

1996

Cristofolini L, Viceconti M, Cappello A, Toni A. Mechanical validation of whole bone composite femur models. J Biomech. April 1996;29(4):525-535.

2001

Yamashita J, Furman BR, Rawls HR, Wang X, Agrawal CM. The use of dynamic mechanical analysis to assess the viscoelastic properties of human cortical bone. J Biomed Mater Res. 2001;B58(1):47-53.

1986

Martens M, van Audekercke R, de Meester P, Mulier JC. Mechanical behaviour of femoral bones in bending loading. J Biomech. 1986;19(6):443-454.

1981

Huiskes R, Janssen JD, Slooff TJ. A detailed comparison of experimental and theoretical stress-analyses of a human femur. In: Cowin SC, ed. Mechanical Properties of Bone. The Joint ASME-ASCE Applied Mechnics, Fluids Engineering and Bioengineering Conference; June 22-24, 1981; Boulder, CO. New York, NY: American Society of Mechical Engineers; 1981:211-234.

1980

Martens M, van Audekercke R, de Meester P, Mulier JC. The mechanical characteristics of the long bones of the lower extremity in torsional loading. J Biomech. 1980;13(8):667-676.

1983

Huiskes R, Chao EYS. A survey of finite element analysis in orthopedic biomechanics: the first decade. J Biomech. 1983;16(6):385-409.

2007

Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg. April 2007;89A(4):780-785.

1993

Bergmann G, Graichen F, Rohlmann A. Hip joint loading during walking and running, measured in two patients. J Biomech. August 1993;26(8):969-990.

1985

Cheal EJ, Hayes WC, Lee CH, Snyder BD, Miller J. Stress analysis of a condylar knee tibial component: influence of metaphyseal shell properties and cement injection depth. J Orthop Res. 1985;3(4):424-434.

Year	Entry
2021	Gee A, Bougherara H, Schemitsch EH, Zdero R. Biomechanical design using in-vitro finite element modeling of distal femur fracture plates made from semi-rigid materials versus traditional metals for post-operative toe-touch weight-bearing. Med Eng Phys. January 2021;87:95-103.
2014	Bagheri Z. Biomechanical Development and Analysis of a New Carbon-Fiber/flax/epoxy Plate for Repairing Femur Fractures [PhD thesis]. Ryerson University; 2014.

Year

Entry

2021

Gee A, Bougherara H, Schemitsch EH, Zdero R. Biomechanical design using in-vitro finite element modeling of distal femur fracture plates made from semi-rigid materials versus traditional metals for post-operative toe-touch weight-bearing. Med Eng Phys. January 2021;87:95-103.

2014

Bagheri Z. Biomechanical Development and Analysis of a New Carbon-Fiber/flax/epoxy Plate for Repairing Femur Fractures [PhD thesis]. Ryerson University; 2014.