In vitro assessment of the motion of equine proximal sesamoid bones relative to the third metacarpal bone under physiologic midstance loads

Sarah K. Shaffer Mechanical and Aerospace Engineering Graduate Group, University of California-Davis, Davis, CA 95616.
Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616.

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Natalia Sachs College of Engineering; J. D. Wheat Veterinary Orthopedic Research Laboratory and Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

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Tanya C. Garcia College of Engineering; J. D. Wheat Veterinary Orthopedic Research Laboratory and Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

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David P. Fyhrie Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616.
Department of Orthopedic Surgery, School of Medicine, University of California-Davis, Davis, CA 95616.

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Susan M. Stover College of Engineering; J. D. Wheat Veterinary Orthopedic Research Laboratory and Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

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Abstract

OBJECTIVE

To assess the motion of the proximal sesamoid bones (PSBs) relative to the third metacarpal bone (MC3) of equine forelimbs during physiologic midstance loads.

SAMPLE

8 musculoskeletally normal forelimbs (7 right and 1 left) from 8 adult equine cadavers.

PROCEDURES

Each forelimb was harvested at the mid-radius level and mounted in a material testing system so the hoof could be moved in a dorsal direction while the radius and MC3 remained vertical. The PSBs were instrumented with 2 linear variable differential transformers to record movement between the 2 bones. The limb was sequentially loaded at a displacement rate of 5 mm/s from 500 N to each of 4 loads (1.8 [standing], 3.6 [walking], 4.5 [trotting], and 10.5 [galloping] kN), held at the designated load for 30 seconds while lateromedial radiographs were obtained, and then unloaded back to 500 N. The position of the PSBs relative to the transverse ridge of the MC3 condyle and angle of the metacarpophalangeal (fetlock) joint were measured on each radiograph.

RESULTS

The distal edge of the PSBs moved distal to the transverse ridge of the MC3 condyle at 10.5 kN (gallop) but not at lower loads. The palmar surfaces of the PSBs rotated away from each other during fetlock joint extension, and the amount of rotation increased with load.

CONCLUSIONS AND CLINICAL RELEVANCE

At loads consistent with a high-speed gallop, PSB translations may create an articular incongruity and abnormal bone stress distribution that contribute to focal subchondral bone lesions and PSB fracture in racehorses.

Abstract

OBJECTIVE

To assess the motion of the proximal sesamoid bones (PSBs) relative to the third metacarpal bone (MC3) of equine forelimbs during physiologic midstance loads.

SAMPLE

8 musculoskeletally normal forelimbs (7 right and 1 left) from 8 adult equine cadavers.

PROCEDURES

Each forelimb was harvested at the mid-radius level and mounted in a material testing system so the hoof could be moved in a dorsal direction while the radius and MC3 remained vertical. The PSBs were instrumented with 2 linear variable differential transformers to record movement between the 2 bones. The limb was sequentially loaded at a displacement rate of 5 mm/s from 500 N to each of 4 loads (1.8 [standing], 3.6 [walking], 4.5 [trotting], and 10.5 [galloping] kN), held at the designated load for 30 seconds while lateromedial radiographs were obtained, and then unloaded back to 500 N. The position of the PSBs relative to the transverse ridge of the MC3 condyle and angle of the metacarpophalangeal (fetlock) joint were measured on each radiograph.

RESULTS

The distal edge of the PSBs moved distal to the transverse ridge of the MC3 condyle at 10.5 kN (gallop) but not at lower loads. The palmar surfaces of the PSBs rotated away from each other during fetlock joint extension, and the amount of rotation increased with load.

CONCLUSIONS AND CLINICAL RELEVANCE

At loads consistent with a high-speed gallop, PSB translations may create an articular incongruity and abnormal bone stress distribution that contribute to focal subchondral bone lesions and PSB fracture in racehorses.

Contributor Notes

Address correspondence to Dr. Stover (smstover@ucdavis.edu).
  • 1.

    Johnson BJ, Stover SM, Daft BM, et al. Causes of death in racehorses over a 2 year period. Equine Vet J 1994;26:327330.

  • 2.

    California Horse Racing Board Postmortem Examination Program 2017–2018 annual report. Davis, Calif: California Horse Racing Board, 2019.

    • Search Google Scholar
    • Export Citation
  • 3.

    Stover SM. The epidemiology of Thoroughbred racehorse injuries. Clin Tech Equine Pract 2003;2:312322.

  • 4.

    Anthenill LA, Gardner IA, Pool RR, et al. Comparison of macrostructural and microstructural bone features in Thoroughbred racehorses with and without midbody fracture of the proximal sesamoid bone. Am J Vet Res 2010;71:755765.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5.

    Stover SM. Diagnostic workup of upper-limb stress fractures and proximal sesamoid bone stress remodeling, in Proceedings. Am Assoc Equine Pract 2013;59:427435.

    • Search Google Scholar
    • Export Citation
  • 6.

    Shaffer SK, To C, Garcia TC, et al. Subchondral focal osteopenia associated with proximal sesamoid bone fracture in Thoroughbred racehorses. Equine Vet J 2020:112.

    • Search Google Scholar
    • Export Citation
  • 7.

    Janes JG, Kennedy LA, Garrett KS, et al. Common lesions of the distal end of the third metacarpal/metatarsal bone in racehorse catastrophic breakdown injuries. J Vet Diagn Invest 2017;29:431436.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    Pool RR, Meagher DM. Pathologic findings and pathogenesis of racetrack injuries. Vet Clin North Am Equine Pract 1990;6:130.

  • 9.

    Park RD. Equine diagnostic imaging—part 1: radiology. In: Stashak TS, ed. Adams’ lameness in horses. 5th ed. Philadelphia: Lippincott Williams and Wilkins, 2002;228231.

    • Search Google Scholar
    • Export Citation
  • 10.

    Butcher MT, Ashley-Ross MA. Fetlock joint kinematics differ with age in Thoroughbred racehorses. J Biomech 2002;35:563571.

  • 11.

    Setterbo J, Garcia T, Campbell I, et al. Forelimb kinematics of galloping Thoroughbred racehorses measured on dirt, synthetic, and turf track surfaces (P235). In: The engineering of sport 7. Paris: Springer Paris, 2009;437446.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Clayton HM, Sha D, Stick J, et al. 3D kinematics of the equine metacarpophalangeal joint at walk and trot. Vet Comp Orthop Traumatol 2007;20:8691.

    • Search Google Scholar
    • Export Citation
  • 13.

    Hodson E, Clayton HM, Lanovaz JL. The forelimb in walking horses: 1. Kinematics and ground reaction forces. Equine Vet J 2000;32:287294.

  • 14.

    Harrison SM, Whitton RC, Kawcak CE, et al. Relationship between muscle forces, joint loading and utilization of elastic strain energy in equine locomotion. J Exp Biol 2010;213:39984009.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Colahan P, Piotrowski G, Poulos P. Kinematic analysis of the instant centers of rotation of the equine metacarpophalangeal joint. Am J Vet Res 1988;49:15601565.

    • Search Google Scholar
    • Export Citation
  • 16.

    Swanstrom MD, Zarucco L, Hubbard M, et al. Musculoskeletal modeling and dynamic simulation of the Thoroughbred equine forelimb during stance phase of the gallop. J Biomech Eng 2005;127:318328.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Singer E, Garcia T, Stover S. How do metacarpophalangeal joint extension, collateromotion and axial rotation influence dorsal surface strains of the equine proximal phalanx at different loads in vitro? J Biomech 2013;46:738744.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Setterbo JJ, Garcia TC, Campbell IP, et al. Hoof accelerations and ground reaction forces of Thoroughbred racehorses measured on dirt, synthetic, and turf track surfaces. Am J Vet Res 2009;70:12201229.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Schryver HF, Bartel DL, Langrana N, et al. Locomotion in the horse: kinematics and external and internal forces in the normal equine digit in the walk and trot. Am J Vet Res 1978;39:17281733.

    • Search Google Scholar
    • Export Citation
  • 20.

    Brama PA, Karssenberg D, Barneveld A, et al. Contact areas and pressure distribution on the proximal articular surface of the proximal phalanx under sagittal plane loading. Equine Vet J 2001;33:2632.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Hjertén G, Drevemo S. Semi-quantitative analysis of hoof-strike in the horse. J Biomech 1994;27:9971004.

  • 22.

    Eckstein F, Jacobs CR, Merz BR. Mechanobiological adaptation of subchondral bone as a function of joint incongruity and loading. Med Eng Phys 1997;19:720728.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23.

    Schnabel LV, Redding WR. Diagnosis and management of proximal sesamoid bone fractures in the horse. Equine Vet Educ 2018;30:450455.

  • 24.

    Anthenill LA, Stover SM, Gardner IA, et al. Association between findings on palmarodorsal radiographic images and detection of a fracture in the proximal sesamoid bones of forelimbs obtained from cadavers of racing Thoroughbreds. Am J Vet Res 2006;67:858868.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Vilar JM, Pinedo M, De Mier J, et al. Equine metacarpophalangeal joint surface contact changes during walk, trot and gallop. J Equine Vet Sci 1995;15:315319.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 26.

    Liley H, Davies H, Firth E, et al. The effect of the sagittal ridge angle on cartilage stress in the equine metacarpo-phalangeal (fetlock) joint. Comput Methods Biomech Biomed Engin 2017;20:110.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    Harrison SM, Whitton RC, King M, et al. Forelimb muscle activity during equine locomotion. J Exp Biol 2012;215:29802991.

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