An anatomical and histological study of the equine proximal manica flexoria

Judith A. Findley; Emanuele E. Ricci; Ellen E. Singer

doi:10.3415/VCOT-16-01-0016

Veterinary and Comparative Orthopaedics and Traumatology, Table of Contents

Vet Comp Orthop Traumatol 2017; 30(02): 91-98
DOI: 10.3415/VCOT-16-01-0016

Original Research

Schattauer GmbH

An anatomical and histological study of the equine proximal manica flexoria

Judith A. Findley

¹Chine House Veterinary Hospital, Sileby Hall, Sileby, UK

,

Emanuele E. Ricci

²Pathology Group, Institute of Veterinary Sciences, University of Liverpool, Leahurst, Neston, UK

,

Ellen E. Singer

³Department of Musculoskeletal Biology, Institute of Aging and Chronic Disease, Institute of Veterinary Sciences, University of Liverpool, Leahurst, Neston, UK

› Author Affiliations

Abstract

Summary

Objectives: The main aim was to describe the gross and histological appearance of the equine manica flexoria and to identify any differences between the forelimbs and hind-limbs. An additional aim was to relate the findings to diagnostic and surgical anatomy of the manica flexoria.

Methods: Measurements of the manica flex-oria were made on cadaveric limbs from horses free from pathology within the digital flexor tendon sheath. Histological sections, stained with haematoxylin and eosin and alcian- periodic acid schiff, were evaluated based on three micro-anatomical zones from dorsal to palmar or plantar. The prevalent tenocyte morphology, number, and distribution of blood vessels and nerves were described in each zone. Forelimb and hindlimb measurements were compared using a Students T-test.

Results: Proximally, the manica flexoria attaches to the digital flexor tendon sheath via a reflection of areolar tissue. The fibrous manica flexoria is longer in the forelimb (32.0 ± 4.2 mm) than the hindlimb (29.4 ± 3.8 mm) (p = 0.04), with the areolar portion longer in the hindlimb (22.9 ± 5.3 mm) compared to the forelimb (16.7 ± 4.3 mm) limb (p = 0.0005). Histologically, degenerate blood vessels were prevalent in the palmar/ plantar regions and were associated with chondrocyte-like tenocytes, indicative of fibrocartilagenous metaplasia.

Clinical significance: The study has provided a detailed anatomical description of the manica flexoria relevant for interpretation of diagnostic and surgical evaluation. Fibrocartilaginous metaplasia occurs on the palmar/plantar surfaces of the manica flex-oria.

Keywords

Manica flexoria - anatomy - fibrocartilaginous metaplasia - equine

Full Text

References

References
1 Denoix JM.. Functional anatomy of tendons and ligaments in the distal limbs (manus and pes). Vet Clin North Am Eq Pract 1994; 10: 273-316.
2 Jordana M., Cornillie P., Oosterlinck M.. et al. Anatomical description of the presence and variability of the digital manica flexoria in the equine digital flexor tendon sheath. Anat Histol Embryol 2017; 46: 9-16.
3 Smith MR., Wright IM.. Noninfected tenosynovitis of the digital flexor tendon sheath: a retrospective analysis of 76 cases. Equine Vet J 2006; 38: 134-141.
4 Arensburg L., Wilderjans H., Simon O.. et al. Nonseptic tenosynovitis of the digital flexor tendon sheath caused by longitudinal tears in the digital flexor tendons: a retrospective study of 135 tenoscopic procedures. Equine Vet J 2011; 43: 660-668.
5 Findley JA., De Oliveira F., Bladon B.. Tenoscopic surgical treatment of tears of the manica flexoria in 53 horses. Vet Surg 2012; 41: 924-930.
6 Fiske-Jackson AR., Barker WH., Eliashar E.. et al. The use of intrathecal analgesia and contrast radiography as preoperative diagnostic methods for digital flexor tendon sheath pathology. Equine Vet J 2013; 45: 36-40.
7 Stanley RL., Patterson-Kane JC., Ralphs JR.. et al. Are there distinct subtypes of tenocytes which relate to age and tendon function. J Bone Joint Surg 2006; 88 Supplement III 380.
8 Blunden A., Murray R., Dyson S.. Lesions of the deep digital flexor tendon in the digit: a correlative MRI and post mortem study in control and lame horses. Equine Vet J 2009; 41: 25-33.
9 Beck S., Blunden T., Dyson S.. et al. Are matrix and vascular changes involved in the pathogenesis of deep digital flexor tendon injury in the horse?. Vet J 2011; 189: 289-295.
10 Nixon AJ., Sams AE., Ducharme NG.. Endoscopically assisted annular ligament release in horses. Vet Surg 1993; 22: 501-507.
11 Redding WR.. Evaluation of the equine digital flexor tendon sheath using diagnostic ultrasound and contrast radiography. Vet Radiol Ultrasound 1995; 35: 42-48.
12 Back W., Schamhardt HC., Hartman W.. et al. Kinematic differences between the distal portions of the forelimbs and hind limbs of horses at the trot. Am J Vet Res 1995; 56: 1522-1528.
13 Clayton HM., Back W.. Hind Limb Function. In Back W., Clayton HM.. editors Equine Locomotion. 2nd ed. London: Elsevier/Saunders; 2013: 127-145.
14 Parsons KJ., Spence AJ., Morgan R.. et al. High speed field kinematics of foot contact in elite galloping horses in training. Equine Vet J 2011; 43: 216-222.
15 Benjamin M., Ralphs JR.. Fibrocartilage in tendons and ligaments--an adaptation to compressive load. J Anat 1998; 193 Pt 4 481-494.
16 Wren TA., Beaupre GS., Carter DR.. Mechanobiology of tendon adaptation to compressive loading through fibrocartilaginous metaplasia. J Rehabil Res Dev 2000; 37: 135-143.
17 Vogel KG.. Tendon structure and response to changing mechanical load. J Musculoskeletal Neuronal Interact 2003; 3: 323-325.
18 Provenzano PP., Alejandro-Osorio AL., Valhmu WB.. et al. Intrinsic fibroblast-mediated remodeling of damaged collagenous matrices in vivo. Matrix Biol 2005; 23: 543-555.
19 Malaviya P., Butler DL., Smith F.. et al. Adaptive in vivo remodeling of the flexor tendon fibrocartilage-rich region in response to altered loading. Trans Orthop Res Soc 1996; 21: 4-8.
20 Crevier-Denoix N., Collobert C., Sannaa M.. et al. Mechanical correlatiosn derived from segmental histologic study of the equine superficial digital flexor tendon, from foal to adult. Am J Vet Res 1998; 59: 969-977.
21 Pohlin F., Edinger J., Jenner F.. et al. Anatomic and histologic features and ultrasonographic appearance of the collateral ligaments of the metacarpophalangeal and metatarsophalangeal joints in cadaveric limbs from horses without lameness. Am J Vet Res 2014; 75: 1089-1098.
22 Blunden A., Dyson S., Murray R.. et al. Histopathology in horses with chronic palmar foot pain and age-matched controls. Part 2: The deep digital flexor tendon. Equine Vet J 2006; 38: 23-27.
23 Millar NL., Reilly JH., Kerr SC.. et al. Hypoxia: a critical regulator of early human tendinopathy. Ann Rheum Dis 2012; 71: 302-310.
24 Bassett CAL., Hermann I.. Influence of oxygen concentration and mechanical factors on differentiation of connective tissue in vitro. Nature 1961; 190: 460-461.
25 Murphy CL., Thoms BL., Rasilaben JV.. et al. HIF-mediated articular chondrocyte function: prospects for cartilage repair. Arthritis Res Ther 2009; 11: 213-220.
26 Petersen W., Stein V., Bobka T.. Structure of the human tibialis anterior tendon. J Anat 2000; 197 Pt 4 617-625.
27 Gigante A., Marinelli M., Chillemi C.. et al. Fibrous cartilage in the rotator cuff: A pathogenetic mechanism of tendon tear?. J Shoulder Elbow Surg 2004; 13: 328-332.
28 Blunden A., Dyson S., Murray R.. et al. Histopathology in horses with chronic palmar foot pain and age-matched controls. Part 1: Navicular bone and related structures. Equine Vet J 2006; 38: 15-22.