Decreased knee adduction moment does not guarantee decreased medial contact force during gait

Jonathan P Walter, Darryl D D'Lima, Clifford W Colwell Jr, Benjamin J Fregly, Jonathan P Walter, Darryl D D'Lima, Clifford W Colwell Jr, Benjamin J Fregly

Abstract

Excessive contact force is believed to contribute to the development of medial compartment knee osteoarthritis. The external knee adduction moment (KAM) has been identified as a surrogate measure for medial contact force during gait, with an abnormally large peak value being linked to increased pain and rate of disease progression. This study used in vivo gait data collected from a subject with a force-measuring knee implant to assess whether KAM decreases accurately predict corresponding decreases in medial contact force. Changes in both quantities generated via gait modification were analyzed statistically relative to the subject's normal gait. The two gait modifications were a "medial thrust" gait involving knee medialization during stance phase and a "walking pole" gait involving use of bilateral walking poles. Reductions in the first (largest) peak of the KAM (32-33%) did not correspond to reductions in the first peak of the medial contact force. In contrast, reductions in the second peak and angular impulse of the KAM (15-47%) corresponded to reductions in the second peak and impulse of the medial contact force (12-42%). Calculated reductions in both KAM peaks were highly sensitive to rotation of the shank reference frame about the superior-inferior axis of the shank. Both peaks of medial contact force were best predicted by a combination of peak values of the external KAM and peak absolute values of the external knee flexion moment (R(2) = 0.93). Future studies that evaluate the effectiveness of gait modifications for offloading the medial compartment of the knee should consider the combined effect of these two knee moments.

Published by Wiley Periodicals, Inc. J Orthop Res 28:1348-1354, 2010.

Figures

Figure 1
Figure 1
Mean curves for (a) external knee adduction moment and (b) internal medial contact force over stance phase calculated from five trials of normal, medial thrust, and walking pole gait.
Figure 2
Figure 2
Peak and impulse values of (a) external knee adduction moment and (b) internal medial contact force for the curves shown in Figure 1. Error bars indicate ± 1 standard deviation. Star (*) denotes statistically significant difference from normal trials.
Figure 3
Figure 3
Mean curves for (a) external knee flexion moment, (b) knee flexion angle, and (c) hip internal rotation angle over stance phase calculated from five trials of normal, medial thrust, and walking pole gait.
Figure 4
Figure 4
Peak values of (a) external knee flexion moment, (b) knee flexion angle, and (c) hip internal rotation angle for the curves shown in Figure 3. Error bars indicate ± 1 standard deviation. Star (*) denotes statistically significant difference from normal trials.
Figure 5
Figure 5
Sensitivity of R2 values between internal medial contact force and external knee adduction moment to rotation of the shank reference frame about the superior-inferior axis of the shank. Results are reported for corresponding a) first peak, b) second peak, and c) impulse values. Linear regression analyses were performed using data from 15 gait trials (five trials from each of the three gait patterns). The two data points on each curve indicate R2 values for nominal (0 degrees) and optimal rotation values.

References

    1. Lawrence RC, Felson DT, Helmick CG, et al. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis and Rheumatism. 2008;58:26–35.
    1. Roos H, Adalberth T, Dahlberg L, Lohmander LS. Osteoarthritis of the knee after injury to the anterior cruciate ligament or meniscus: the influence of time and age. Osteoarthritis and Cartilage. 1995;3:261–267.
    1. Setton LA, Mow VC, Howell DS. Mechanical behavior of articular cartilage in shear is altered by transection of the anterior cruciate ligament. Journal of Orthopaedic Research. 1995;13:473–482.
    1. Frost HM. Perspectives: A biomechanical model of the pathogenesis of arthroses. The Anatomical Record. 1994;240:19–31.
    1. D’Lima DD, Townsend CP, Arms SW, et al. An implantable telemetry device to measure intra-articular tibial forces. Journal of Biomechanics. 2005;38:299–304.
    1. Kaufman KR, Kovacevic N, Irby SE, Colwell CW. Instrumented implant for measuring tibiofemoral forces. Journal of Biomechanics. 1996;29:667–671.
    1. Andriacchi TP. Dynamics of knee malalignment. Orthopedic Clinics of North America. 1994;25:395–403.
    1. Sharma L, Hurwitz DE, Thonar EJMA, et al. Knee adduction moment, serum hyaluronan level, and disease severity in medial tibiofemoral osteoarthritis. Arthritis & Rheumatism. 1998;41:1233–1240.
    1. Thorp LE, Sumner DR, Wimmer MA, Block JA. Relationship between pain and medial knee joint loading in mild radiographic knee osteoarthritis. Arthritis & Rheumatism. 2007;57:1254–1260.
    1. Miyazaki T, Wada M, Kawahara H, et al. Dynamic load at baseline can predict radiographic disease progression in medial compartment knee osteoarthritis. Annals of the Rheumatic Diseases. 2002;61:617–622.
    1. Zhao D, Banks SA, Mitchell KH, et al. Correlation between the knee adduction torque and medial contact force for a variety of gait patterns. Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society. 2007;25:789–797.
    1. Schache AG, Fregly BJ, Crossley KM, et al. The effect of gait modification on the external knee adduction moment is reference frame dependent. Clinical Biomechanics. 2008;23:601–608.
    1. Manal K, McClay I, Richards J, et al. Knee moment profiles during walking: errors due to soft tissue movement of the shank and the influence of the reference coordinate system. Gait & Posture. 2002;15:10–17.
    1. Reinbolt JA, Haftka RT, Chmielewski TL, Fregly BJ. A computational framework to predict post-treatment outcome for gait-related disorders. Medical Engineering & Physics. 2008;30:434–443.
    1. Fregly BJ, D’Lima DD, Colwell CW., Jr Effective gait patterns for offloading the medial compartment of the knee. Journal of Orthopaedic Research. 2009;27:1016–1021.
    1. Fregly BJ, Reinbolt JA, Rooney KL, et al. Design of patient-specific gait modifications for knee osteoarthritis rehabilitation. IEEE Transactions on Biomedical Engineering. 2007;54:1687–1695.
    1. Fregly BJ, Rooney KL, Reinbolt JA. Predicted gait modifications to reduce the peak knee adduction torque. Proceedings of the XXth Congress of the International Society of Biomechanics; Cleveland, OH. 2005.
    1. Barrios JA, Davis IS. A gait modification to reduce the external knee adduction moment at the knee: a case study. Proceedings of the 31st Annual Meeting of the American Society of Biomechanics; Palo Alto, CA. 2007.
    1. Kaufman KR, Hughes C, Morrey BF, et al. Gait characteristics of patients with knee osteoarthritis. Journal of Biomechanics. 2001;34:907–915.
    1. Thorp LE, Sumner DR, Block JA, et al. Knee joint loading differs in individuals with mild compared with moderate medial knee osteoarthritis. Arthritis and Rheumatism. 2006;54:3842–3849.
    1. Baliunas AJ, Hurwitz DE, Ryals AB, et al. Increased knee joint loads during walking are present in subjects with knee osteoarthritis. Osteoarthritis and Cartilage. 2002;10:573–579.
    1. Prodromos CC, Andriacchi TP, Galante JO. A relationship between gait and clinical changes following high tibial osteotomy. Journal of Bone and Joint Surgery. 1985;67A:1188–1194.
    1. Kean CO, Birmingham TB, Garland JS, et al. Moments and muscle activity after high tibial osteotomy and anterior cruciate ligament reconstruction. Medicine and Science in Sports and Exercise. 2009;41:612–619.
    1. Maly MR, Costigan PA, Olney SJ. Mechanical factors relate to pain in knee osteoarthritis. Clinical Biomechanics. 2008;23:796–805.
    1. Erhart JC, Dyrby C, D’Lima DD, et al. Reduction in the Medical Compartment Force Correlates with the Reduction in Knee Adduction Moment Using a Variable-Stiffness Shoe with an Instrumented Knee. Proceedings of the ASME 2009 Summer Bioengineering Conference; Lake Tahoe, CA. 2009.
    1. Sharma L, Song J, Felson DT, et al. The role of knee alignment in disease progression and functional decline in knee osteoarthritis. The Journal of the American Medical Association. 2001;286:188–195.

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