In-Vivo Knee Loading Before and After ACL Transection in an Animal Model

Transection of the anterior cruciate ligament (ACL) in animals has been shown to induce osteoarthritis (OA) in the knee. Joint instability and changes in knee loading are believed to initiate OA. However, muscular forces which ultimately determine knee loading have not been quantified in vivo in an ACL transection model. Consequently, changes in knee loading following ACL transection are not known, and the relationship between changes in knee loading and the pathogenesis of OA remains unclear. This study investigated changes in knee loading following ACL transection in the cat. The specific objectives were: a) to measure patellar tendon and gastrocnemius forces, electromyographic activity in knee extensor and flexor muscles, external hindlimb kinematics, and ground reaction forces (GRFs); b) to quantify changes in patellofemoral contact forces using a planar model of the patella with patellar tendon forces and patellofemoral geometry as input; and c) to determine if changes in GRFs following ACL transection are representative of changes in knee loading.

Measurements were performed in both hindlimbs during unrestrained locomotion of six animals. In four animals, measurements were performed before and five, seven, and nine days following uni-lateral ACL transection. In two animals, measurements were performed in the intact hindlimbs, four days after sham surgery, and five days after ACL transection. The muscular forces, knee extensor EMGs, GRFs and knee range of motion were not altered by sham surgery but were decreased in the ACL-deficient limbs and increased in the contralateral limbs in all animals following ACL transection. Patellofemoral contact forces in the ACL-deficient hindlimbs were decreased by about 30% following ACL transection. While the relative reduction in peak vertical GRFs and peak patellar tendon forces was similar, the detailed time-history of knee loading cannot be inferred from externally measured forces. For the first time, knee extensor forces have been measured following ACL transection in an experimental model of joint injury. The results of this study suggest that ACL transection causes a general unloading of the knee. The decreased knee loading immediately following ACL transection is speculated to play an important role in triggering degenerative responses of the knee.

Year	Entry
1973	Smidt GL. Biomechanical analysis of knee flexion and extension. J Biomech. January 1973;6(1):79-92.
1995	Heegaard J, Leyvraz PF, Curnier A, Rakotomanana L, Huiskes R. The biomechanics of the human patella during passive knee flexion. J Biomech. November 1995;28(11):1265-1279.
1984	Huberti HH, Hayes WC. Patellofemoral contact pressures: the influence of Q-angle and tendofemoral contact. J Bone Joint Surg. June 1984;66A(5):715-724.
1975	Seireg A, Arvikar RJ. The prediction of muscular load sharing and joint forces in the lower extremities during walking. J Biomech. March 1975;8(2):89-102.
1995	Haut RC, Ide TM, De Camp CE. Mechanical responses of the rabbit patello-femoral joint to blunt impact. J Biomech Eng. November 1995;117(4):402-408.
1978	Crowninshield RD, Johnston RC, Andrews JG, Brand RA. A biomechanical investigation of the human hip. J Biomech. 1978;11(1-2):75-85.
1973	Seireg A, Arvikar RJ. A mathematical model for evaluation of forces in lower extremeties of the musculo-skeletal system. J Biomech. May 1973;6(3):313-326.
1970	Morrison JB. The mechanics of the knee joint in relation to normal walking. J Biomech. January 1970;3(1):51-61.
1990	Spoor CW, van Leeuwen JL, Meskers CGM, Titulaer AF, Huson A. Estimation of instantaneous moment arms of lower-leg muscles. J Biomech. 1990;23(12):1247-1259.
1994	Freeman PM, Natarajan RN, Kimura JH, Andriacchi TP. Chondrocyte cells respond mechanically to compressive loads. J Orthop Res. May 1994;12(3):311-320.
1989	Sah RL-Y, Kim Y-J, Doong J-YH, Grodzinsky AJ, Plass AHK, Sandy JD. Biosynthetic response of cartilage explants to dynamic compression. J Orthop Res. 1989;7(5):619-636.
1991	Hirokawa S. Three-dimensional mathematical model analysis of the patellofemoral joint. J Biomech. 1991;24(8):659-671.
1992	Hale JE, Brown TD. Contact stress gradient detection limits of pressensor film. J Biomech Eng. August 1992;114(3):352-357.
1988	Gray ML, Pizzanelli AM, Grodzinsky AJ, Lee RC. Mechanical and physicochemical determinants of the chondrocyte biosynthetic response. J Orthop Res. November 1988;6(6):777-792.
1994	Urban JPG. The chondrocyte: a cell under pressure. Br J Rheumatol. October 1994;33(10):901-908.
1989	Yamaguchi GT, Zajac FE. A planar model of the knee joint to characterize the knee extensor mechanism. J Biomech. 1989;22(1):1-10.
1978	Caterson B, Lowther DA. Changes in the metabolism of the proteoglycans from sheep articular cartilage in response to mechanical stress. Biochim Biophys Acta. May 17, 1978;540(3):412-422.
1986	Woltring HJ. A Fortran package for generalized, cross-validatory spline smoothing and differentiation. Adv Eng Softw. April 1986;8(2):104-113.
1991	Hall AC, Urban JPG, Gehl KA. The effects of hydrostatic pressure on matrix synthesis in articular cartilage. J Orthop Res. January 1991;9(1):1-10.
1986	van Eijden TMGJ, Kouwenhoven E, Verburg J, Weijs WA. A mathematical model of the patellofemoral joint. J Biomech. 1986;19(3):219-229.
1967	Paul JP. Forces transmitted by joints in the human body. Proc Inst Mech Eng. 1967;181(pt 3J):8-15.
1972	Radin EL, Paul IL, Rose RM. Role of mechanical factors in pathogenesis of primary osteoarthritis. Lancet. March 4, 1972;299(7749):519-522.
1973	Radin EL, Parker HG, Pugh JW, Steinberg RS, Paul IL, Rose RM. Response of joints to impact loading, III: relationship between trabecular microfractures and cartilage degeneration. J Biomech. January 1973;6(1):51-57.
1984	Palmoski MJ, Brandt KD. Effects of static and cyclic compressive loading on articular cartilage plugs in vitro. Arthritis Rheum. June 1984;27(6):675-681.
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.

Year

Entry

1973

Smidt GL. Biomechanical analysis of knee flexion and extension. J Biomech. January 1973;6(1):79-92.

1995

Heegaard J, Leyvraz PF, Curnier A, Rakotomanana L, Huiskes R. The biomechanics of the human patella during passive knee flexion. J Biomech. November 1995;28(11):1265-1279.

1984

Huberti HH, Hayes WC. Patellofemoral contact pressures: the influence of Q-angle and tendofemoral contact. J Bone Joint Surg. June 1984;66A(5):715-724.

1975

Seireg A, Arvikar RJ. The prediction of muscular load sharing and joint forces in the lower extremities during walking. J Biomech. March 1975;8(2):89-102.

1995

Haut RC, Ide TM, De Camp CE. Mechanical responses of the rabbit patello-femoral joint to blunt impact. J Biomech Eng. November 1995;117(4):402-408.

1978

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

1973

Seireg A, Arvikar RJ. A mathematical model for evaluation of forces in lower extremeties of the musculo-skeletal system. J Biomech. May 1973;6(3):313-326.

1970

Morrison JB. The mechanics of the knee joint in relation to normal walking. J Biomech. January 1970;3(1):51-61.

1990

Spoor CW, van Leeuwen JL, Meskers CGM, Titulaer AF, Huson A. Estimation of instantaneous moment arms of lower-leg muscles. J Biomech. 1990;23(12):1247-1259.

1994

Freeman PM, Natarajan RN, Kimura JH, Andriacchi TP. Chondrocyte cells respond mechanically to compressive loads. J Orthop Res. May 1994;12(3):311-320.

1989

Sah RL-Y, Kim Y-J, Doong J-YH, Grodzinsky AJ, Plass AHK, Sandy JD. Biosynthetic response of cartilage explants to dynamic compression. J Orthop Res. 1989;7(5):619-636.

1991

Hirokawa S. Three-dimensional mathematical model analysis of the patellofemoral joint. J Biomech. 1991;24(8):659-671.

1992

Hale JE, Brown TD. Contact stress gradient detection limits of pressensor film. J Biomech Eng. August 1992;114(3):352-357.

1988

Gray ML, Pizzanelli AM, Grodzinsky AJ, Lee RC. Mechanical and physicochemical determinants of the chondrocyte biosynthetic response. J Orthop Res. November 1988;6(6):777-792.

1994

Urban JPG. The chondrocyte: a cell under pressure. Br J Rheumatol. October 1994;33(10):901-908.

1989

Yamaguchi GT, Zajac FE. A planar model of the knee joint to characterize the knee extensor mechanism. J Biomech. 1989;22(1):1-10.

1978

Caterson B, Lowther DA. Changes in the metabolism of the proteoglycans from sheep articular cartilage in response to mechanical stress. Biochim Biophys Acta. May 17, 1978;540(3):412-422.

1986

Woltring HJ. A Fortran package for generalized, cross-validatory spline smoothing and differentiation. Adv Eng Softw. April 1986;8(2):104-113.

1991

Hall AC, Urban JPG, Gehl KA. The effects of hydrostatic pressure on matrix synthesis in articular cartilage. J Orthop Res. January 1991;9(1):1-10.

1986

van Eijden TMGJ, Kouwenhoven E, Verburg J, Weijs WA. A mathematical model of the patellofemoral joint. J Biomech. 1986;19(3):219-229.

1967

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

1972

Radin EL, Paul IL, Rose RM. Role of mechanical factors in pathogenesis of primary osteoarthritis. Lancet. March 4, 1972;299(7749):519-522.

1973

Radin EL, Parker HG, Pugh JW, Steinberg RS, Paul IL, Rose RM. Response of joints to impact loading, III: relationship between trabecular microfractures and cartilage degeneration. J Biomech. January 1973;6(1):51-57.

1984

Palmoski MJ, Brandt KD. Effects of static and cyclic compressive loading on articular cartilage plugs in vitro. Arthritis Rheum. June 1984;27(6):675-681.

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.

Year	Entry
1998	Herzog W, Diet S, Suter E, Mayzus P, Leonard TR, Müller C, Wu JZ, Epstein M. Material and functional properties of articular cartilage and patellofemoral contact mechanics in an experimental model of osteoarthritis. J Biomech. December 1998;31(12):1137-1145.
1996	Maitland ME. Longitudinal Measurement of Tibial Motion Relative to the Femur During Passive Displacements and Femoral Nerve Stimulation in the ACL-Deficient Cat Model of Osteoarthritis [PhD thesis]. Calgary, AB: University of Calgary; August 1996.
1997	Boyd SK. A 3D in-Situ Model for Patellofemoral Joint Contact Analysis in the Normal and Anterior Cruciate Ligament Deficient Knee [Master's thesis]. Calgary, AB: University of Calgary; April 1997.
2003	Craig STT. Effects of in-Vitro Joint Loading on Articular Cartilage Chondrocyte Viability [Master's thesis]. Calgary, AB: University of Calgary; December 2003.

Year

Entry

1998

Herzog W, Diet S, Suter E, Mayzus P, Leonard TR, Müller C, Wu JZ, Epstein M. Material and functional properties of articular cartilage and patellofemoral contact mechanics in an experimental model of osteoarthritis. J Biomech. December 1998;31(12):1137-1145.

1996

Maitland ME. Longitudinal Measurement of Tibial Motion Relative to the Femur During Passive Displacements and Femoral Nerve Stimulation in the ACL-Deficient Cat Model of Osteoarthritis [PhD thesis]. Calgary, AB: University of Calgary; August 1996.

1997

Boyd SK. A 3D in-Situ Model for Patellofemoral Joint Contact Analysis in the Normal and Anterior Cruciate Ligament Deficient Knee [Master's thesis]. Calgary, AB: University of Calgary; April 1997.

2003

Craig STT. Effects of in-Vitro Joint Loading on Articular Cartilage Chondrocyte Viability [Master's thesis]. Calgary, AB: University of Calgary; December 2003.