Equis ISSN 2398-2977

Navicular bone: syndrome

Synonym(s): Navicular bursitis, Navicular disease, Podotrochleosis, Podotrochlitis, Caudal heel pain/disease

Contributor(s): Olin Balch, Patrick Colahan, Simon Curtis, Martin Gough, Helen Herinckx, Jarred Williams

Introduction

  • Cause: multifactorial, hoof and pastern conformation, concussion, breed and activity associated.
  • Signs: bilateral forelimb lameness Musculoskeletal: gait evaluation.
  • Diagnosis: clinical presentation, perineural analgesia, radiography Forelimb: radiography, MRI Magnetic resonance imaging.
  • Treatment: corrective shoeing and analgesics may help. Navicular bursa injections with corticosteroids, navicular bursoscopy, neurectomy for selected chronic cases.
  • Prognosis: guarded.
Print off the Owner factsheets on Navicular bursitis and Navicular disease to give to your clients.

Pathogenesis

Etiology

  • Unclear, repetitive trauma is a common history.
  • Conformation Musculoskeletal: conformation.
  • Soft tissue injury in the hoof misdiagnosed as navicular bone disease.

Predisposing factors

General

  • Trimming/shoeing which induces a broken-back axis to the hoof pastern region.
  • Long toe and low/flat heel.
  • Chronic heel bruising.

Pathophysiology

  • Recently, advances in diagnostic imaging techniques, eg MRI scanning, have improved understanding of the pathological changes involved.
  • Proposed theories:
    • Biomechanics (currently more popular):
      • Repetitive trauma to the navicular bone during chronic repetitive loading by pressure from the deep digital flexor tendon → the development of a bursitis, tendonitis, adhesion formation within the bursa and between bursa and deep digital flexor tendon, and an inflammatory process → lameness.
      • Cumulative cyclic loading → sagittal bending of the navicular bone → microdamage → adaptive failure of the bone (low bone mass, poor osteocyte connectivity, low osteophyte density).
    • Vascular:
      • Interruption of circulation to and from navicular bone → remodeling.
      • Thromboses within the navicular bone → hypertension → remodeling.
  • Upright pastern conformation accompanied by long toe/low heel conformation (underrun heels) affects biomechanical relationship of the deep digital flexor tendon, navicular bursa, other soft tissue structure in the food (ie impar ligament) and navicular bone predisposing to navicular damage.
  • Chronic pain in the heels may → heel unloading → increased force over navicular bone → degenerative changes in navicular bone.

Timecourse

  • Once established the lesion is chronic and progressive.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource
  • Mitchell A, Watts A E, Ebetino F H & Suva L J (2019) Bisphosphonate use in the horse: what is good and what is not? BMC Vet Res 15 (1), 211 PubMed.
  • Arguelles D et al (2019) Clinical efficacy of clodronic acid in horses diagnosed with navicular syndrome: A field study using objective and subjective lameness evaluation. Res Vet Sci 125, 298-304 PubMed.
  • Schoonover M J et al (2018) Quantitative assessment of intravenous regional limb perfusion of tiludronate as an adjunctive treatment for lameness caused by navicular syndrome in horses. Am J Vet Res 79 (12), 1313-1320 PubMed.
  • Johnson S A, Barrett M F & Frisbie D D (2018) Additional palmaroproximal-palmarodistal oblique radiographic projections improve accuracy of detection and characterization of equine flexor cortical lysis. Vet Radiol Ultrasound 59 (4), 387-395 PubMed.
  • Nottrott K, De Guio C, Khairoun A & Schramme M (2017) An ultrasound-guided, tendon-sparing, lateral approach to injection of the navicular bursa. Equine Vet J 49 (5), 655-661 PubMed.
  • Coomer R, Thomas H & McKane S (2013) Current concepts of navicular syndrome: diagnosis and treatment. In Pract 35 (6), 325-335 VetMedResource.
  • Dyson S, Murray R, Schramme M & Blunden T (2011) Current concepts of navicular disease. Equine Vet Educ 23 (1), 27-39 VetMedResource.
  • Rijkenhuizen A B M (2006) Navicular disease: a review of what's new. Equine Vet J 38 (1), 82-88 PubMed.
  • Grewal J S, McClure S R, Booth L C, Evans R B & Caston S S (2004) Assessment of the ultrasonographic characteristics of the podotrochlear apparatus in clinically normal horses and horses with navicular syndrome. JAVMA 225 (12), 1881-1888 PubMed.
  • Denoix J M, Thibaud D & Riccio B (2003) Tiludronate as a new therapeutic agent in the treatment of navicular disease: a double-blind placebo-controlled clinical trial. Equine Vet J 35 (4), 407-413 PubMed.
  • Dik K J et al (2001) Relationships of age and shape of the navicular bone to the development of navicular disease - a radiographical study. Equine Vet J 33 (2), 172-175 PubMed.
  • McGuigan & Wilson A M (2001) The effect of bilateral palmar digital nerve analgesia on the compressive force experienced by the navicular bone in horse with navicular disease. Equine Vet J 33 (2), 166-171 PubMed.
  • Wilson A M et al (2001) The force and contact stress on the navicular bone during trot locomotion in sound horses and horses with navicular disease. Equine Vet J 33 (2), 159-165 PubMed.
  • Willemen M A, Savelberg H H C M & Barneveld A (1999) The effect of orthopedic shoeing on the force exerted by the deep digital flexor tendon on the navicular bone in horses. Equine Vet J 31 (1), 25-30 PubMed.
  • Wright I M et al (1998) Gross histologic and histomorphometric features of the navicular bone related structures in the horse. Equine Vet J 30 (3), 220-234 PubMed.
  • Wilson A M (1997) Treatment of navicular disease. Vet Rec 141 (23), 608 PubMed.
  • Gabriel A et al (1997) Morphometric study of the equine navicular bone, comparison between fore and rear limbs. Zentralbl Veterinarmed A 44 (9-10), 579-594 PubMed.
  • Dik K J et al (1995) Role of navicular bone shape in the pathogenesis of navicular disease, a radiologic study. Equine Vet J 27 (5), 390-393 PubMed.
  • Hickman J (1989) Navicular disease - What are we talking about? Equine Vet J 21 (6), 395-398 PubMed.
  • Colles C (1982) Navicular disease and its treatment. In Practice (2), 29-36 PubMed.

Other sources of information

  • Schneider R S, Gavin P R & Tucker R L (2003) What MRI is Teaching us about Navicular Disease. In: Proc 49th AAEP Convention. pp 210-219.


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