Accessory Ligament of the DDF tendon and it relationship to the SDF tendon

Accessory Ligament of the Deep Digital Flexor Tendon of the Horse Forelimb and Its Relationship with the Superficial Digital Flexor Tendon: A Plastination, Histological, and Morphometry Study
Animals (Basel). 2024 Oct 14;14(20):2952. doi: 10.3390/ani14202952.
Authors
Gulsum Eren 1 2 , Octavio López-Albors 1 , Ruth Guilabert Segura 1 , Joana Jordan Montesinos 1 , Rafael Latorre 1
Affiliations

1 Department of Anatomy and Comparative Pathological Anatomy, Veterinary Faculty, University of Murcia, 30100 Murcia, Spain.
2 Department of Anatomy, Veterinary Faculty, University of Uludag, Bursa 16059, Türkiye.

PMID: 39457884
DOI: 10.3390/ani14202952

Abstract

The accessory ligament of the deep digital flexor tendon (AL-DDFT) plays a crucial role in the stay apparatus of the horse. This study aimed to investigate the anatomical relationship between the AL-DDFT, the superficial digital flexor tendon (SDFT), and other structures in the metacarpal region. Sixteen distal forelimbs from eight horses, aged 1 to 6 years, were evaluated through macroscopic, microscopic, and morphometric analyses, utilizing detailed dissection, E12 plastinated sections, and histological analysis. During lateral dissection, a connection was observed between the AL-DDFT and the SDFT. Histological evaluation revealed that this connection was a fibrous band (FB), extending the common synovial sheath (CSS) to the SDFT, along with associated collagen fibrils of the epiligament and peritenon. Additionally, two distinct forms of the AL-DDFT were identified, Type I and Type II, with Type II showing a greater cross-sectional area (CSA) than Type I. While numerous morphological and morphometric studies have explored the AL-DDFT and related structures, research incorporating plastination-based morphological and histological evaluations remains scarce. The findings provide valuable insights for both the morphological and clinical assessment of structures within the metacarpal region.

Keywords: E12 sheet plastination; accessory ligament; cross-sectional area; deep digital flexor tendon; horse; superficial digital flexor tendon.