English
French
The anatomy and physiology of the suspensory apparatus of the distal phalanx.
Abstract: The equine hoof capsule protects the softer, more sensitive, structures within. Failure of the connection between hoof and bone (suspensory apparatus of the distal phalanx or SADP) results in the crippling lameness of laminitis. Active basal cell proliferation occurs principally in tubular hoof and proximal and distal lamellae. The remaining lamellae are virtually non-proliferative and the hoof wall moves past the stationary distal phalanx, by controlled activation and inhibition of constituent proteases. The lamellar corium derives most of its blood supply from the branches of the terminal arch which perforate the distal phalanx. Valveless veins within the foot can be exploited clinically for retrograde venous therapy or contrast radiography (venography). The basement membrane (BM) forms the interface between the lamellar epidermis and the adjacent dermis and the plasma membrane of each lamellar basal cell is attached to the BM by numerous electron dense adhesion plaques or hemidesmosomes the ultimate attachment unit of the SADP. Laminitis destroys and dislocates the BM and its components and without an intact, functional BM, the structure and function of the lamellar epidermis is pathologically compromised. Transcription and activation of constituent proteases occurs in normal hoof lamellae but in increased amounts during laminitis.
Copyright 2010 Elsevier Inc. All rights reserved.
Publication Date: 2010-04-13 PubMed ID: 20381734DOI: 10.1016/j.cveq.2010.01.005Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Review
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This study thoroughly analyzes the structure and functioning of the suspensory apparatus of the distal phalanx (SADP), a part of the horse’s hoof that when malfunctioning can contribute to a severe lameness condition called laminitis.
Overview of SADP and Role in Horse Hoof
- The research focuses on the vital role the suspensory apparatus of the distal phalanx (SADP) plays in the health and functionality of a horse’s hoof.
- The equine hoof capsule is the outer protective shell, safeguarding the interior structures against damage.
- The critical relationship between the hoof and bone is maintained by the SADP, with its failure leading to laminitis, a painful and debilitating condition.
Cell Proliferation and SADP
- Within the SADP, most basal cell proliferation happens within the tubular hoof and proximal and distal lamellae.
- The remaining lamellae are mostly non-proliferative. They exist in a state where the hoof wall progresses past the non-moving distal phalanx thanks to a controlled activation and inhibition of constituent proteases.
Blood Supply and Veins in the SADP
- The blood supply for lamellar corium is primarily derived from the branches of the terminal arch perforating the distal phalanx.
- The foot has valveless veins that can be utilized for medical procedures such as retrograde venous therapy or contrast radiography (venography).
Role of Basement Membrane (BM) and Effects of Laminitis
- The interface between the lamellar epidermis and the neighboring dermis is created by the basement membrane (BM).
- The lamellar basal cell’s plasma membrane attaches to the BM using numerous electron-dense adhesion plaques or hemidesmosomes, which are the ultimate unit of attachment for the SADP.
- In cases of laminitis, the BM and its components get destroyed or displaced.
- Without a functional BM, both the structure and function of the lamellar epidermis becomes pathologically compromised, leading to severe foot pain and lameness in horses.
- Normal hoof lamellae undergo transcription and activation of constituent proteases. However, these processes are increased during episodes of laminitis.
Cite This Article
APA
Pollitt CC.
(2010).
The anatomy and physiology of the suspensory apparatus of the distal phalanx.
Vet Clin North Am Equine Pract, 26(1), 29-49.
https://doi.org/10.1016/j.cveq.2010.01.005 Publication
Researcher Affiliations
- School of Veterinary Science, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia. c.pollitt@mailbox.uq.edu.au
MeSH Terms
- Animals
- Basement Membrane / anatomy & histology
- Basement Membrane / physiology
- Foot Diseases / etiology
- Foot Diseases / veterinary
- Hemidesmosomes
- Hoof and Claw / anatomy & histology
- Hoof and Claw / blood supply
- Hoof and Claw / innervation
- Hoof and Claw / physiology
- Horse Diseases / etiology
- Horses / anatomy & histology
- Horses / physiology
- Ligaments / anatomy & histology
- Ligaments / physiology
- Ligaments, Articular / anatomy & histology
- Ligaments, Articular / physiology
- Toe Phalanges / anatomy & histology
- Toe Phalanges / physiology
Citations
This article has been cited 18 times.- Castro-Mesa AF, Resende Faleiros R, Martu00ednez-Aranzales JR. Transmural Ultrasonography in the Evaluation of Horse Hoof Internal Structures: Comparative Quantitative Findings-Part 2.. Animals (Basel) 2023 Jul 11;13(14).
- Hobbs SJ, Curtis S, Martin J, Sinclair J, Clayton HM. Hoof Matters: Developing an Athletic Thoroughbred Hoof.. Animals (Basel) 2022 Nov 11;12(22).
- Sundberg JP, Galantino-Homer H, Fairfield H, Ward-Bailey PF, Harris BS, Berry M, Pratt CH, Gott NE, Bechtold LS, Kaplan PR, Durbin-Johnson BP, Rocke DM, Rice RH. Witch Nails (Krt90whnl): A spontaneous mouse mutation affecting nail growth and development.. PLoS One 2022;17(11):e0277284.
- Montgomery JB, Klein M, Boire JR, Beck C, Hu00e4usermann D, Maksimenko A, Hall CJ. Synchrotron CT of an equine digit at the Australian Synchrotron Imaging and Medical Beamline.. J Synchrotron Radiat 2021 Nov 1;28(Pt 6):1769-1777.
- Sato F, Otsuka N, Kuwano A. Toe white line separation associated with the notch (crena marginalis) on the distal phalanges in Thoroughbred yearling horses.. J Vet Med Sci 2021 Nov 16;83(11):1745-1749.
- Cequier A, Sanz C, Rodellar C, Barrachina L. The Usefulness of Mesenchymal Stem Cells beyond the Musculoskeletal System in Horses.. Animals (Basel) 2021 Mar 25;11(4).
- Cassimeris L, Engiles JB, Galantino-Homer H. Interleukin-17A pathway target genes are upregulated in Equus caballus supporting limb laminitis.. PLoS One 2020;15(12):e0232920.
- Armstrong C, Cassimeris L, Da Silva Santos C, Micoogullari Y, Wagner B, Babasyan S, Brooks S, Galantino-Homer H. The expression of equine keratins K42 and K124 is restricted to the hoof epidermal lamellae of Equus caballus.. PLoS One 2019;14(9):e0219234.
- Cassimeris L, Engiles JB, Galantino-Homer H. Detection of endoplasmic reticulum stress and the unfolded protein response in naturally-occurring endocrinopathic equine laminitis.. BMC Vet Res 2019 Jan 10;15(1):24.
- Angelone M, Conti V, Biacca C, Battaglia B, Pecorari L, Piana F, Gnudi G, Leonardi F, Ramoni R, Basini G, Dotti S, Renzi S, Ferrari M, Grolli S. The Contribution of Adipose Tissue-Derived Mesenchymal Stem Cells and Platelet-Rich Plasma to the Treatment of Chronic Equine Laminitis: A Proof of Concept.. Int J Mol Sci 2017 Oct 11;18(10).
- Lancaster LS, Bowker RM. Acupuncture Points of the Horse's Distal Thoracic Limb: A Neuroanatomic Approach to the Transposition of Traditional Points.. Animals (Basel) 2012 Sep 17;2(3):455-71.
- Holl HM, Gao S, Fei Z, Andrews C, Brooks SA. Generation of a de novo transcriptome from equine lamellar tissue.. BMC Genomics 2015 Oct 3;16:739.
- Linardi RL, Megee SO, Mainardi SR, Senoo M, Galantino-Homer HL. Expression and localization of epithelial stem cell and differentiation markers in equine skin, eye and hoof.. Vet Dermatol 2015 Aug;26(4):213-e47.
- Leise BS, Watts MR, Roy S, Yilmaz AS, Alder H, Belknap JK. Use of laser capture microdissection for the assessment of equine lamellar basal epithelial cell signalling in the early stages of laminitis.. Equine Vet J 2015 Jul;47(4):478-88.
- Wang L, Pawlak EA, Johnson PJ, Belknap JK, Alfandari D, Black SJ. Expression and activity of collagenases in the digital laminae of horses with carbohydrate overload-induced acute laminitis.. J Vet Intern Med 2014 Jan-Feb;28(1):215-22.
- Wang L, Pawlak EA, Johnson PJ, Belknap JK, Eades S, Stack S, Cousin H, Black SJ. Impact of laminitis on the canonical Wnt signaling pathway in basal epithelial cells of the equine digital laminae.. PLoS One 2013;8(2):e56025.
- Wang L, Pawlak E, Johnson PJ, Belknap JK, Alfandari D, Black SJ. Effects of cleavage by a disintegrin and metalloproteinase with thrombospondin motifs-4 on gene expression and protein content of versican and aggrecan in the digital laminae of horses with starch gruel-induced laminitis.. Am J Vet Res 2012 Jul;73(7):1047-56.
- Pawlak E, Wang L, Johnson PJ, Nuovo G, Taye A, Belknap JK, Alfandari D, Black SJ. Distribution and processing of a disintegrin and metalloproteinase with thrombospondin motifs-4, aggrecan, versican, and hyaluronan in equine digital laminae.. Am J Vet Res 2012 Jul;73(7):1035-46.
Secure Payments
Satisfaction Guarantee
We offer a 60-day guarantee to ensure you are completely satisfied.
Fast & Free Shipping
We provide fast and free shipping on all orders over $40.