• 1. Radin EL, Paul IL, Lowy M. A comparison of the dynamic force transmitting properties of subchondral bone and articular cartilage. J Bone Joint Surg Am 1970; 52:444456.

    • Search Google Scholar
    • Export Citation
  • 2. Radin EL, Paul IL. Importance of bone in sparing articular cartilage from impact. Clin Orthop Relat Res 1971; 78:342344.

  • 3. Palmer JL, Bertone AL. Joint biomechanics in the pathogenesis of traumatic arthritis. In: McIlwraith CW, Trotter GW, eds. Joint disease in the horse. Philadelphia: WB Saunders Co, 1996;104119.

    • Search Google Scholar
    • Export Citation
  • 4. Müller-Gerbl M. The subchondral bone plate. Adv Anat Embryol Cell Biol 1998; 141:1134.

  • 5. Kawcak CE, McIlwraith CW, Norrdin RW, et al. The role of subchondral bone in joint disease: a review. Equine Vet J 2001; 33:120126.

  • 6. Frost HM. Skeletal structural adaptations to mechanical usage (SATMU): 1. Redefining Wolff's law: the bone modeling problem. Anat Rec 1990; 226:403413.

    • Search Google Scholar
    • Export Citation
  • 7. Rubin CT, Lanyon LE. Osteoregulatory nature of mechanical stimuli, function as a determinant for adaptive remodeling in bone. J Orthop Res 1987; 5:300310.

    • Search Google Scholar
    • Export Citation
  • 8. Young DR, Richardson DW, Markel MD, et al. Mechanical and morphometric analysis of the third carpal bone of Thoroughbreds. Am J Vet Res 1991; 52:402409.

    • Search Google Scholar
    • Export Citation
  • 9. Pauwels F. Biomechanics of the locomotor apparatus. New York: Springer, 1980.

  • 10. Müller-Gerbl M, Putz R, Kenn R. Demonstration of subchondral bone density patterns by three-dimensional CT osteoabsorptiometry as a noninvasive method for in vivo assessment of individual long-term stresses in joints. J Bone Miner Res 1992; 7:S411S418.

    • Search Google Scholar
    • Export Citation
  • 11. Eckstein F, Müller-Gerbl M, Steinlechner M, et al. Subchondral bone density in the human elbow assessed by computed tomography osteoabsorptiometry: a reflection of the loading history of the joint surfaces. J Orthop Res 1995; 13:268278.

    • Search Google Scholar
    • Export Citation
  • 12. von Eisenhart-Rothe R, Eckstein F, Müller-Gerbl M, et al. Direct comparison of contact areas, contact stress and subchondral mineralization in human hip joint specimens. Anat Embryol (Berl) 1997; 195:279288.

    • Search Google Scholar
    • Export Citation
  • 13. Samii VF, Les CM, Schulz KS, et al. Computed tomographic osteoabsorptiometry of the elbow joint in clinically normal dogs. Am J Vet Res 2002; 63:11591166.

    • Search Google Scholar
    • Export Citation
  • 14. Dickomeit MJ, Böttcher P, Hecht S, et al. Topographic and age-dependent distribution of subchondral bone density in the elbow joints of clinically normal dogs. Am J Vet Res 2011; 72:491499.

    • Search Google Scholar
    • Export Citation
  • 15. Young BD, Samii VF, Mattoon JS, et al. Subchondral bone density and cartilage degeneration patterns in osteoarthritic metacarpal condyles of horses. Am J Vet Res 2007; 68:841849.

    • Search Google Scholar
    • Export Citation
  • 16. Drum MG, Kawcak CE, Norrdin RW, et al. Comparison of gross and histopathologic findings with quantitative computed tomographic bone density in the distal third metacarpal bone of racehorses. Vet Radiol Ultrasound 2007; 48:518527.

    • Search Google Scholar
    • Export Citation
  • 17. Kawcak CE, McIlwraith CW, Firth EC. Effects of early exercise on metacarpophalangeal joints in horses. Am J Vet Res 2010; 71:405411.

  • 18. Changoor A, Hurtig MB, Runciman RJ, et al. Mapping of donor and recipient site properties for osteochondral graft reconstruction of subchondral cystic lesions in the equine stifle joint. Equine Vet J 2006; 38:330336.

    • Search Google Scholar
    • Export Citation
  • 19. Böttcher P, Zeissler M, Oechtering G, et al. Mapping subchondral bone density of selected donor and recipient sites for autologous osteochondral transplantation in the canine stifle joint using computed tomographic osteoabsorptiometry. Vet Surg 2010; 39:496503.

    • Search Google Scholar
    • Export Citation
  • 20. Drum MG, Les CM, Park RD, et al. Comparison of mean bone densities of three preparations of the distal portion of the equine third metacarpal bone measured by use of quantitative computed tomography. Am J Vet Res 2008; 69:891893.

    • Search Google Scholar
    • Export Citation
  • 21. Cann CE. Quantitative CT for determination of bone mineral density: a review. Radiology 1988; 166:509522.

  • 22. Pearce GP, May-Davis S, Greaves D. Femoral asymmetry in the Thoroughbred racehorse. Aust Vet J 2005; 83:367370.

  • 23. Baxter GM. Subchondral cystic lesions in horses. In: McIlwraith CW, Trotter GW, eds. Joint disease in the horse. Philadelphia: WB Saunders Co, 1996;384397.

    • Search Google Scholar
    • Export Citation
  • 24. Ondrouch AS. Cyst formation in osteoarthritis. J Bone Joint Surg Br 1963; 45:755760.

  • 25. Maulet BEB, Mayhew IG, Jones E, et al. Radiographic anatomy of the soft tissue attachments of the equine stifle. Equine Vet J 2005; 37:530535.

    • Search Google Scholar
    • Export Citation
  • 26. Fowlie JG, Arnoczky SP, Stick JA, et al. Meniscal translocation and deformation throughout the range of motion of the equine stifle joint: an in vitro cadaveric study. Equine Vet J 2011; 43:259264.

    • Search Google Scholar
    • Export Citation
  • 27. Merritt JS, Pandy MG, Brown NAT, et al. Mechanical loading of the distal end of the third metacarpal bone in horses during walking and trotting. Am J Vet Res 2010; 71:508514.

    • Search Google Scholar
    • Export Citation
  • 28. Baker GJ, Moustafa MAI, Boero MJ, et al. Caudal cruciate ligament function and injury in the horse. Vet Rec 1987; 121:319321.

  • 29. Hanson PD, Markel MD. Radiographic geometric variation of equine long bones. Am J Vet Res 1994; 55:12201227.

  • 30. Watson KM, Stitson DJ, Davies HMS. Third metacarpal bone length and skeletal asymmetry in the Thoroughbred racehorse. Equine Vet J 2003; 35:712714.

    • Search Google Scholar
    • Export Citation
  • 31. Wells DL. Lateralised behavior in the domestic dog, Canis familiaris. Behav Processes 2003; 61:2735.

  • 32. Roth ED. ‘Handedness’ in snakes? Lateralization of coiling behavior in a cottonmouth, Agkistrodon piscivorus leucostoma, population. Anim Behav 2003; 66:337341.

    • Search Google Scholar
    • Export Citation
  • 33. Bisazza A, Cantalupo C, Capocchiano M, et al. Population lateralization and social behavior: a study with 16 species of fish. Laterality 2000; 5:269284.

    • Search Google Scholar
    • Export Citation
  • 34. Ventollini N, Ferrero EA, Sponza S, et al. Laterality in the wild: preferential hemifield use during predatory and sexual behavior in the black-winged stilt. Anim Behav 2005; 69:10771084.

    • Search Google Scholar
    • Export Citation
  • 35. Robins A, Rogers LJ. Lateralized prey-catching responses in the cane toad, Bufo marinus: analysis of complex visual stimuli. Anim Behav 2004; 68:767775.

    • Search Google Scholar
    • Export Citation
  • 36. Vallortigara G & Bisazza A. How ancient is brain lateralization? In: Rogers LJ, Andrew RJ, eds. Comparative vertebrate lateralization. Cambridge, England: Cambridge University Press, 2002;969.

    • Search Google Scholar
    • Export Citation
  • 37. Murphy J, Sutherland A, Arkins S. Idiosyncratic motor laterality in the horse. Appl Anim Behav Sci 2005; 91:297310.

  • 38. McGreevy PD, Rogers LJ. Motor and sensory laterality in Thoroughbred horses. Appl Anim Behav Sci 2005; 92:337352.

  • 39. Williams DE, Norris BJ. Laterality in stride pattern preference in racehorses. Anim Behav 2007; 74:941950.

  • 40. Emmerson TD, Lawes TJ, Goodship AE, et al. Dual-energy X-ray absorptiometry measurement of bone-mineral density in the distal aspect of the limbs in racing Greyhounds. Am J Vet Res 2000; 61:12141219.

    • Search Google Scholar
    • Export Citation
  • 41. Lipscomb VJ, Lawes TJ, Goodship AE, et al. Asymmetric densitometric and mechanical adaptation of the left fifth metacarpal bone in racing greyhounds. Vet Rec 2001; 148:308311.

    • Search Google Scholar
    • Export Citation
  • 42. Johnson KA, Skinner GA, Muir P. Site-specific adaptive remodeling of Greyhound metacarpal cortical bone subjected to asymmetrical cyclic loading. Am J Vet Res 2001; 62:787793.

    • Search Google Scholar
    • Export Citation
  • 43. Boudrieau RJ, Dee JF, Dee LG. Central tarsal bone fractures in the racing Greyhound: a review of 114 cases. J Am Vet Med Assoc 1984; 184:14861491.

    • Search Google Scholar
    • Export Citation
  • 44. Johnson KA, Piermattei DL, Davis PE, et al. Characteristics of accessory carpal bone fractures in 50 racing Greyhounds. Vet Comp Orthop Traumatol 1988; 2:104107.

    • Search Google Scholar
    • Export Citation
  • 45. Bellenger CR, Johnson KA, Davis PE, et al. Fixation of metacarpal and metatarsal fractures in Greyhounds. Aust Vet J 1981; 57:205211.

  • 46. Davies HMS, Watson KM. Third metacarpal bone laterality asymmetry and midshaft dimensions in Thoroughbred racehorses. Aust Vet J 2005; 83:224226.

    • Search Google Scholar
    • Export Citation
  • 47. Zekas LJ, Bramlage LR, Embertson RM, et al. Characterisation of the type and location of fractures of the third metacarpal/metatarsal condyles in 135 horses in central Kentucky (1986–1994). Equine Vet J 1999; 31:304308.

    • Search Google Scholar
    • Export Citation
  • 48. Parkin TDH, Clegg PD, French NP, et al. Catastrophic fracture of the lateral condyle of the third metacarpus/metatarsus in UK racehorses—fracture descriptions and pre-existing pathology. Vet J 2006; 171:157165.

    • Search Google Scholar
    • Export Citation
  • 49. Schneider RK, Bramlage LR, Gabel AA, et al. Incidence, location and classification of 371 third carpal bone fractures in 313 horses. Equine Vet J Suppl 1988;(6):S33s42.

    • Search Google Scholar
    • Export Citation
  • 50. Peloso JG, Mundy GD, Cohen ND. Prevalence of, and risk factors associated with, musculoskeletal racing injuries of Thoroughbreds. J Am Vet Med Assoc 1994; 204:620626.

    • Search Google Scholar
    • Export Citation
  • 51. Rick MC, O'Brien TR, Pool RR, et al. Condylar fractures of the third metacarpal bone and third metatarsal bone in 75 horses: radiographic features, treatments, and outcome. J Am Vet Med Assoc 1983; 183:287296.

    • Search Google Scholar
    • Export Citation
  • 52. Richardson DW. Medial condylar fractures of the third metatarsal bone in horses. J Am Vet Med Assoc 1984; 185:761765.

  • 53. Dyson S, McNie K, Weekes J, et al. Scintigraphic evaluation of the stifle in normal horses and horses with forelimb lameness. Vet Radiol Ultrasound 2007; 48:378382.

    • Search Google Scholar
    • Export Citation
  • 54. Dyson S, Murray R, Branch M, et al. The sacroiliac joints: evaluation using nuclear scintigraphy part 1: the normal horse. Equine Vet J 2003; 35:226232.

    • Search Google Scholar
    • Export Citation
  • 55. Murray RC, Dyson SJ, Weekes JS, et al. Nuclear scintigraphic evaluation of the distal tarsus region in normal horses. Vet Radiol Ultrasound 2004; 45:345351.

    • Search Google Scholar
    • Export Citation
  • 56. Weekes JS, Murray RC, Dyson SJ. Scintigraphic evaluation of metacarpophalangeal and metatarsopahalangeal joints in clinically sound horses. Vet Radiol Ultrasound 2004; 45:8590.

    • Search Google Scholar
    • Export Citation

Medial femoral condyle morphometrics and subchondral bone density patterns in Thoroughbred racehorses

Wade T. Walker DVM1, Christopher E. Kawcak DVM, PhD2, and Ashley E. Hill DVM, PhD3
View More View Less
  • 1 Equine Orthopaedic Research Laboratory, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523.
  • | 2 Equine Orthopaedic Research Laboratory, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523.
  • | 3 California Animal Health and Food Safety Laboratory, University of California-Davis, Davis, CA 95617.

Abstract

Objective—To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs.

Sample—Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness.

Procedures—The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subchondral bone plate densities; and subchondral trabecular bone densities were analyzed in multiple sections in 5 frontal planes and 3 sagittal planes and were compared between left and right MFCs.

Results—MFC width, length, and height did not differ between left and right limbs. Regions of interest in the right caudoaxial subchondral bone plate and subchondral trabecular bone were significantly denser than their corresponding left regions of interest in the frontal and sagittal planes. A concavity in the otherwise convex articular surface of the cranial aspect of the MFC was identified in 11 of 12 specimens.

Conclusions and Clinical Relevance—A disparity was identified between left and right subchondral bone density patterns at the caudoaxial aspect of the MFC, which could be attributable to the repetitive asymmetric cyclic loading that North American Thoroughbred racehorses undergo as they race in a counterclockwise direction. The uneven region at the cranial aspect of the MFC could be associated with the development of subchondral bone cysts in horses.

Abstract

Objective—To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs.

Sample—Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness.

Procedures—The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subchondral bone plate densities; and subchondral trabecular bone densities were analyzed in multiple sections in 5 frontal planes and 3 sagittal planes and were compared between left and right MFCs.

Results—MFC width, length, and height did not differ between left and right limbs. Regions of interest in the right caudoaxial subchondral bone plate and subchondral trabecular bone were significantly denser than their corresponding left regions of interest in the frontal and sagittal planes. A concavity in the otherwise convex articular surface of the cranial aspect of the MFC was identified in 11 of 12 specimens.

Conclusions and Clinical Relevance—A disparity was identified between left and right subchondral bone density patterns at the caudoaxial aspect of the MFC, which could be attributable to the repetitive asymmetric cyclic loading that North American Thoroughbred racehorses undergo as they race in a counterclockwise direction. The uneven region at the cranial aspect of the MFC could be associated with the development of subchondral bone cysts in horses.

Contributor Notes

Dr. Walker's present address is Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.

Supported by grants from the CSU College Research Council and the Merial-CSU Veterinary Scholars Program.

The authors thank Dr. Natasha Werpy, Dr. Katrina Easton, and Billie Arceneaux for technical assistance.

Address correspondence to Dr. Kawcak (ckawcak@colostate.edu).