References

Becht JL, Park RD, Kraft SL, Steyn PF, Wrigley RH. Radiographic interpretation of normal skeletal variations and pseudolesions in the equine foot. Vet Clin North Am Equine Pract. 2001; 17:(1)1-18 https://doi.org/10.1016/S0749-0739(17)30072-X

Berry CR, Pool RR, Stover S, O'Brien TR, Koblik PD. Radiographic/morphologic investigation of a radiolucent crescent within the flexor central eminence of the navicular bone in thoroughbreds. Am J Vet Res. 1992; 53:(9)1604-1611

Biggi M, Dyson S. Comparison between radiological and magnetic resonance imaging lesions in the distal border of the navicular bone with particular reference to distal border fragments and osseous cyst-like lesions. Equine Vet J. 2010; 42:(8)707-712 https://doi.org/10.1111/j.2042-3306.2010.00117.x

Biggi M, Dyson S. High-field magnetic resonance imaging investigation of distal border fragments of the navicular bone in horses with foot pain. Equine Vet J. 2011; 43:(3)302-308 https://doi.org/10.1111/j.2042-3306.2010.00159.x

Blunden A, Dyson S, Murray R, Schramme M. Histopathology in horses with chronic palmar foot pain and age-matched controls. Part 1: navicular bone and related structures. Equine Vet J. 2006; 38:(1)15-22 https://doi.org/10.2746/042516406775374298

Butler JA, Colles CM, Dyson SJ, Kold SE, Poulos PW. Clinical radiology of the horse.Chichester: John Wiley & Sons; 2017

Claerhoudt S, Bergman HJ, Van Der Veen H, Duchateau L, Raes EV, Saunders JH. Differences in the morphology of distal border synovial invaginations of the distal sesamoid bone in the horse as evaluated by computed tomography compared with radiography. Equine Vet J. 2012; 44:(6)679-683 https://doi.org/10.1111/j.2042-3306.2012.00547.x

Colles CM. Interpreting radiographs 1: the foot. Equine Vet J. 1983; 15:(4)297-303 https://doi.org/10.1111/j.2042-3306.1983.tb01804.x

Dik KJ, Belt AJM, van den Broek J. Relationships of age and shape of the navicular bone to the development of navicular disease: a radiological study. Equine Vet J. 2001; 33:(2)172-175 https://doi.org/10.1111/j.2042-3306.2001.tb00596.x

Dik KJ, van den Broek J. Role of navicular bone shape in the pathogenesis of navicular disease: a radiological study. Equine Vet J. 1995; 27:(5)390-393 https://doi.org/10.1111/j.2042-3306.1995.tb04075.x

Dyson S. Variations in the normal radiographic anatomy of equine limbs. In Pract. 1988; 10:(3)119-125 https://doi.org/10.1136/inpract.10.3.119

Dyson S. Radiological interpretation of the navicular bone. Equine Vet Educ. 2011; 23:(2)73-87 https://doi.org/10.1111/j.2042-3292.2010.00168.x

Dyson S, Murray R, Schramme M, Blunden T. Current concepts of navicular disease. Equine Vet Educ. 2011; 23:(1)27-39 https://doi.org/10.1111/j.2042-3292.2010.00172.x

Dyson S, Pool R, Blunden T, Murray R. The distal sesamoidean impar ligament: comparison between its appearance on magnetic resonance imaging and histology of the axial third of the ligament. Equine Vet J. 2010; 42:(4)332-339 https://doi.org/10.1111/j.2042-3306.2010.00068.x

Eliashar E, McGuigan MP, Wilson AM. Relationship of foot conformation and force applied to the navicular bone of sound horses at the trot. Equine Vet J. 2004; 36:(5)431-435 https://doi.org/10.2746/0425164044868378

Hertsch BZR. Roentgenologische Veraenderungen am Strahlbein und ihre Beurteilung. Prakt Tierarzt. 1977; 58:14-19

Hinkle FE, Johnson SA, Selberg KT, Barrett MF. A review of normal radiographical variants commonly mistaken for pathological findings in horses. Equine Vet Educ. 2019; https://doi.org/10.1111/eve.13088

Johnson SA, Barrett MF, Frisbie DD. Additional palmaroproximal-palmarodistal oblique radiographic projections improve accuracy of detection and characterization of equine flexor cortical lysis. Vet Radiol Ultrasound. 2018; 59:(4)387-395 https://doi.org/10.1111/vru.12620

Kaser-Hotz B, Ueltschi G. Radiographic appearance of the navicular bone in sound horses. Vet Radiol Ultrasound. 1992; 33:(1)9-17 https://doi.org/10.1111/j.1740-8261.1992.tb01949.x

Komosa M, Łazowski S, Włodarek JKK, Charuta A, Zdun M. Gross and histological evaluation of early lesions of navicular bone and deep digital flexor tendon in horses. Bulletin of the Veterinary Institute in Pulawy. 2014; 58:(1) https://doi.org/10.2478/bvip-2014-0014

O'Brien TR, Millman TM, Pool RR, Suter PF. Navicular disease in the Thoroughbred horse: a morphologic investigation relative to a new radiographic projection. Vet Radiol. 1975; 16:(2)39-51 https://doi.org/10.1111/j.1740-8261.1975.tb00416.x

Olive J, Videau M. Distal border synovial invaginations of the equine distal sesamoid bone communicate with the distal interphalangeal joint. Vet Comp Orthop Traumatol. 2017; 30:(02)107-110 https://doi.org/10.3415/VCOT-16-08-0120

Park RD. Radiographic examination of the equine foot. Vet Clin North Am Equine Pract. 1989; 5:(1)47-66 https://doi.org/10.1016/S0749-0739(17)30603-X

Pool RR, Meagher DM, Stover SM. Pathophysiology of navicular syndrome. Vet Clin North Am Equine Pract. 1989; 5:(1)109-129 https://doi.org/10.1016/S0749-0739(17)30606-5

Poulos PW, Brown A, Brown E, Gamboa L. On navicular syndrome in the horse: A roentgenological and patho-anatomic study Part II Osseous bodies associated with the impar ligament. Vet Radiol. 1989; 30:54-58 https://doi.org/10.1111/j.1740-8261.1989.tb01786.x

Poulos PW, Smith MF. The nature of enlarged “vascular channels” in the navicular bone of the horse. Vet Radiol. 1988; 29:(2)60-64 https://doi.org/10.1111/j.1740-8261.1988.tb01749.x

Rijkenhuizen ABM, Németh F, Dik KJ, Goedegebuure SA. The arterial supply of the navicular bone in adult horses with navicular disease. Equine Vet J. 1989; 21:(6)418-424 https://doi.org/10.1111/j.2042-3306.1989.tb02187.x

Schramme MC, Murray RC, Blunden AS, Dyson SJ. A comparison between magnetic resonance imaging, pathology, and radiology in 34 limbs with navicular syndrome and 25 control limbs. Proc Am Assoc Equine Practnrs. 2005; 51:348-358

Stashak T. Navicular syndrome (navicular syndrome).Philadelphia: WB Saunders; 1998

Ueltschi G. Podotrochlose-Wert und Häufigkeit röntgenologisch nachweisbarer Veränderungen am Strahlbein. Berl Munch Tierarztl Wochenschr. 1983; 96:(9)308-310

van der Zaag EJ, Weerts EAWS, van den Belt AJM, Back W. Clinicopathological findings in horses with a bi- or tripartite navicular bone. BMC Vet Res. 2016; 12:(1) https://doi.org/10.1186/s12917-016-0698-4

Weaver MP, Shaw DJ, Munaiwa G, Fitzpatrick DP, Bellenger CR. Pressure distribution between the deep digital flexor tendon and the navicular bone, and the effect of raising the heels in vitro. Vet Comp Orthop Traumatol. 2009; 22:(4)278-282 https://doi.org/10.3415/VCOT-08-05-0043

Wilson AM, McGuigan MP, Fouracre L, MacMahon L. The force and contact stress on the navicular bone during trot locomotion in sound horses and horses with navicular disease. Equine Vet J. 2001; 33:(2)159-165 https://doi.org/10.1111/j.2042-3306.2001.tb00594.x

Wintzer HJ, Dämmrich K. Pathogenesis of the so-called navicular disease in horses. Berl Munch Tierarztl Wochenschr. 1971; 84:(12)221-225

Wright IM. A study of 118 cases of navicular disease: radiological features. Equine Vet J. 1993; 25:(6)493-500 https://doi.org/10.1111/j.2042-3306.1993.tb03000.x

Wright I, Douglas J. Biomechanical considerations in the treatment of navicular disease. Vet Rec. 1993; 133:(5)109-114 https://doi.org/10.1136/vr.133.5.109

Wright IM, Kidd L, Thorp BH. Gross, histological and histomorphometric features of the navicular bone and related structures in the horse. Equine Vet J. 1998; 30:(3)220-234 https://doi.org/10.1111/j.2042-3306.1998.tb04491.x

Yorke EH, Judy CE, Saveraid TC, McGowan CP, Caldwell FJ. Distal border fragments of the equine navicular bone: association between magnetic resonance imaging characteristics and clinical lameness. Vet Radiol Ultrasound. 2014; 55:(1)35-44 https://doi.org/10.1111/vru.12082

CPD article: Radiographic interpretation of the navicular bone: a review

02 September 2020
17 mins read
Volume 4 · Issue 5
Figure 1. a. Lateromedial, (b) upright pedal and (c) navicular skyline radiographs of a 14-year-old Quarter Horse gelding with a normal navicular bone. Note the artifactual two linear lucent lines superimposed with proximal P2 as a result of the central sulcus of the frog in b.
Figure 1. a. Lateromedial, (b) upright pedal and (c) navicular skyline radiographs of a 14-year-old Quarter Horse gelding with a normal navicular bone. Note the artifactual two linear lucent lines superimposed with proximal P2 as a result of the central sulcus of the frog in b.

Abstract

Navicular syndrome (navicular disease) plays a major role in the equine industry as a chronic, degenerative, and often career-limiting disease process, affecting a variety of breeds of horses. In addition to clinical signs and diagnostic analgesia, diagnostic imaging plays a key role in the identification of this disease process; radiography is the most widely used imaging modality. In addition to their clinical utility, foot radiographs are a standard element of most pre-purchase examinations. Good radiographic quality and positioning are necessary for accurate interpretation. Radiographic lesions of the navicular bone, such as sclerosis, enlarged synovial invaginations, distal border fragments and flexor cortical erosions, are important to identify and understand because of their potential role in the disease process. This article reviews an approach to radiological evaluation and interpretation of lesions affecting the navicular bone.

Navicular syndrome (navicular disease) is a degenerative syndrome involving the osseous and soft tissue structures of the podotrochlear apparatus (Wright et al, 1998). The degeneration of the podotrochlear apparatus is thought to be the result of biomechanical overloading from a combination of workload and conformation (Wright and Douglas, 1993). Pain originating from this region is estimated to be responsible for at least one-third of chronic forelimb lameness in Quarter Horses, Thoroughbreds, and Warmbloods (Stashak, 1998; Dyson et al, 2011). Because radiography is commonly the first imaging modality performed following lameness evaluation, accurate radiographic interpretation requires well-positioned radiographs with a thorough understanding of normal variants, artefacts, and the spectrum of radiological lesions that can affect the appearance of the navicular bone. This article reviews methodology for evaluation and interpretation of the most frequently encountered radiographic lesions of the navicular bone, based on a review of the literature and the authors' experiences. Note, although navicular lesions occur in both the fore and hind limbs, for ease of discussion the forelimb terminology will be used.

Register now to continue reading

Thank you for visiting UK-VET Equine and reading some of our peer-reviewed content for veterinary professionals. To continue reading this article, please register today.