Topic:Deep Digital Flexor Tendon
The Deep Digital Flexor Tendon (DDFT) is a critical structure in the equine limb, extending from the muscles in the upper leg down to the coffin bone in the hoof. It is responsible for flexing the lower limb and plays a significant role in the horse's movement and weight-bearing capabilities. The DDFT runs behind the cannon bone and passes over the navicular bone before attaching to the pedal bone. Injuries to the DDFT can occur due to overuse, trauma, or degenerative changes, often leading to lameness and requiring careful management. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, injury mechanisms, and treatment options related to the Deep Digital Flexor Tendon in horses.
Ultrasound Morphometry and Mean Echogenicity of Digital Flexor Tendons, Suspensory Ligament, and Accessory Ligament of Digital Deep Flexor Tendon in Gaited Horses. The objective of this study was to evaluate and compare the sonographic characteristics of the digital flexor tendons and ligaments of the palmar/plantar of the metacarpal and metatarsal regions in gaited horses, as well as to establish normal reference ultrasound values for Mangalarga Marchador (MM) and Campeiro breeds. Transverse sonographic images were obtained of 50 adult and healthy horses from the MM (n = 25) and Campeiro (n = 25) breeds. The images were taken in six metacarpal/metatarsal zones, and the following measurements were taken: transverse area, circumference, dorsopalmar/planta...
Interleukin-1β and methylprednisolone acetate demonstrate differential effects on equine deep digital flexor tendon and navicular bone fibrocartilage cells in vitro. To investigate the effects of interleukin-1β (IL-1β) and methylprednisolone acetate (MPA) on equine intrabursal deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) cells in vitro. Methods: Third passage DDFT and NBF cells from 5 healthy donor horses ages 11-17 years euthanized for reasons unrelated to musculoskeletal conditions. Methods: Aggregate cultures were incubated with culture medium alone (control), 10 ng/mL IL-1β, 10 ng/mL IL-1β + 0.05 mg/mL MPA, or 10 ng/mL IL-1β + 0.5 mg/mL MPA for 24 hours. Extracellular matrix (ECM) gene expressions were assessed via rea...
A Randomized, Self-Controlled Case Series Evaluating Core Osteostixis of Osseous Cyst-Like Lesions of the Navicular Bone to Improve Lameness in Horses with Podotrochlear Syndrome. Podotrochlear syndrome is a common cause of lameness in Quarter Horses involving both soft tissue and bony structures within the heel region. Current surgical treatment of podotrochlear syndrome addresses pathological changes affecting the soft tissue structures of the navicular region but does not address either edema or cyst-like lesions of the navicular bone. Unassigned: The objective of this randomized, self-controlled case series was to determine whether core osteostixis improved lameness in Quarter Horses with podotrochlear syndrome characterized by bilateral magnetic resonance imaging (...
Diagnosis and outcome following tenoscopic surgery of the digital flexor tendon sheath in German sports and pleasure horses. Digital flexor tendon sheath (DFTS) pathology is an important cause of lameness in horses. The outcome after surgical treatment is variable and depends on the exact diagnosis. Objective: To (1) describe the prevalence of lesions associated with lameness caused by nonseptic DFTS tenosynovitis in a large population of German sports and pleasure horses; (2) determine the sensitivity and specificity of diagnostic imaging techniques for identifying lesions within the DFTS with tenoscopic diagnosis being the gold standard; (3) explore associations between tenoscopically diagnosed lesions and signalm...
Applicability of ARFI elastography in detecting elasticity changes of the equine superficial digital flexor tendon with induced injury. The objectives of this prospective, experimental study were to describe changes in the stiffness of the equine superficial digital flexor tendon (SDFT) after induced injury, deep digital flexor tendon (DDFT), accessory ligament (AL-DDFT), and suspensory ligament (SL) during 90 days of healing using acoustic radiation force impulse (ARFI) elastography. Eight healthy horses were selected. Preinjury B mode and ARFI evaluations were performed bilaterally in the palmar metacarpal region. Injury was induced only on the left forelimb (G2) by a single injection of collagenase in SDFT, 15 cm distal to ...
Kinetic Analysis in Horses With Deep Digital Flexor Tendinopathy Within the Digit Diagnosed by Magnetic Resonance Imaging. To determine the stance duration and ground reaction forces (GRF) of horses with deep digital flexor (DDF) tendinopathy at the level of the foot and compare the stance duration and GRF to those of clinically sound horses. Unassigned: Prospective clinical study. Unassigned: Sixteen horses (seven horses with bilateral forelimb lameness, four horses with unilateral forelimb lameness, and five horses with no lameness). Unassigned: Analyses of kinetic variables were performed on both forelimbs from sound horses and horses diagnosed with chronic DDF tendinopathy. Stance duration and longitudinal and...
Effect of single and double hemitenotomy on equine deep digital flexor tendon length and strength in experimental load challenges. To evaluate a double hemitenotomy (DHT) technique as an alternative to complete deep digital flexor (DDFT) tenotomy. Methods: Experimental ex vivo study. Methods: Isolated DDFTs (n = 30) and cadaveric forelimbs (n = 16). Methods: In part 1, 15 isolated DDFT pairs were used. Two hemitenotomies were created in 1 DDFT while the other served as reference. Monotonic tensile load was applied. Tendon lengthening, load reduction, and load at failure were recorded. In part 2, 16 cadaveric forelimb pairs were subjected to DHT followed by complete tenotomy (CT) under monotonic compressive load. Diffe...
Leveraging MRI characterization of longitudinal tears of the deep digital flexor tendon in horses using machine learning. While MRI is the modality of choice for the diagnosis of longitudinal tears (LTs) of the deep digital flexor tendon (DDFT) of horses, differentiating between various grades of tears based on imaging characteristics is challenging due to overlapping imaging features. In this retrospective, exploratory, diagnostic accuracy study, a machine learning (ML) scheme was applied to link quantitative features and qualitative descriptors to leverage MRI characteristics of different grades of tearing of the DDFT of horses. A qualitative MRI characteristic scheme, combining tendon morphologic features, alt...
Anatomical position of the palmar/plantar nerves at the metacarpal/metatarsal distal level in horses: An in vivo study by means of ultrasonography. The neurovascular bundle of the equine distal cannon can dynamically vary with limb position, and this can affect the performance of low 4- or 6-point block. This study aims to identify and describe the anatomical position and variations of the lateral and medial palmar/plantar nerve at the metacarpal/metatarsal distal level in horses by ultrasonography. Eight mares underwent ultrasound examination on the lateral and medial palmar/plantar sides of the metacarpus/metatarsus. Images were obtained for measurements of the cross-sectional area of the nerve, distances between the nerve and the skin ...
Using Short Term of High Power Laser Therapy in Horse’s Tendon Injuries. High-power laser therapy has been used as a treatment to cure sports injuries; however, there are no controlled standardized studies on its efficacy. Moreover, high-power laser therapy has been applied for the sport horses field. This study aimed to investigate whether high-power laser therapy can cure tendon disorders and reduce the pain in tendon lesions in injured horses and also to examine the effect of laser therapy on injured horses. This retroactive experiential clinical research was performed on50 racing horses between 5 and 15 years old. They were diagnosed with neither superficial di...
Deep Digital Flexor Tendon Injury at the Level of the Proximal Phalanx in Frontlimbs With Tendon Sheath Distension Characterized by Standing Low-Field Magnetic Resonance Imaging in Horses: 13 Cases (2015-2021). To describe the MRI findings for 13 horses with deep digital flexor tendon (DDFT) injury at the proximal phalanx where the tendon goes from ovoid to bilobed in frontlimbs with tendon sheath distension. In addition, the prognosis of this lesion was assessed. Retrospective case series. Thirteen client-owned horses. Medical records were reviewed, and data were collected regarding signalment, history, MRI findings, and outcomes of horses. Findings of MRI were recorded and whether the case was confirmed with tenoscopy. A diagnosis of DDFT injury at the junction between ovoid and bilobed portio...
Diffusion of dye after perineural injection of the palmar/plantar nerves in two different sites in horses: an ex-vivo study. This study aimed to evaluate the distribution of dye at two perineural injection sites of the palmar/plantar nerves and describe their anatomical variations of positioning at the level of the distal metacarpus/metatarsus in horses. Two ml of 1% methylene blue solution was injected in 24 limbs (12 forelimbs and 12 hindlimbs) of horse cadavers at two different points: Group 1: between the branch of the suspensory ligament and deep digital flexor tendon, and Group 2: between the deep and superficial digital flexor tendons. This was followed by dissection and evaluation of the solution diffusion. ...
Three-Dimensional Segmentation and in silico Comparison of Equine Deep Digital Flexor Tendon Pathology in Horses Undergoing Repeated MRI Examination. The use of magnetic resonance imaging (MRI) has led to increased clinical and research applications using 3D segmentation and reconstructed volumetric data in musculoskeletal imaging. Lesions of the deep digital flexor tendon (DDFT) are a common pathology in horses undergoing MRI. Three-dimensional MRI reconstruction performed for volumetric tendon analysis in horses has not previously been documented. The aim of this proof-of-concept study was to evaluate the 3D segmentation of horses undergoing repeated MRI at several time points and to perform an analysis of the segmented DDFTs across time....
Equine flexor tendon imaging part 2: Current status and future directions in advanced diagnostic imaging, with focus on the deep digital flexor tendon. Flexor tendon injuries are a common cause of lameness and early retirement in equine athletes. While ultrasonography is most frequently utilised, advanced diagnostic imaging modalities are becoming more widely available for detection and monitoring of flexor tendon lesions. Part two of this literature review details current experience with low- and high-field magnetic resonance imaging (MRI) and computed tomography (CT) for the diagnosis of equine flexor tendinopathy with a focus on the deep digital flexor tendon. Implications of the 'magic angle' artefact as well as injection techniques and t...
Equine flexor tendon imaging part 1: Recent developments in ultrasonography, with focus on the superficial digital flexor tendon. Flexor tendon injuries are a major cause of lameness in performance horses and have considerable impact on equine welfare and the wider horse industry. Ageing and repetitive strain frequently cause varying degrees of tendon micro-damage prior to the recognition of clinical tendinopathy. Whilst B-mode ultrasonography is most commonly utilised for detection and monitoring of tendon lesions at the metacarpal/metatarsal level, the emphasis of recent research has focused on the identification of subclinical tendon damage in order to prevent further tendon injury and improve outcomes. The introducti...
Tissue predictability of elastography is low in collagenase induced deep digital flexor tendinopathy. Elastography is an emerging imaging modality for characterizing tendon injury in horses, but its ability to differentiate tissue deformability relative to treatment group and biochemical properties using a prospective, experimental study design remain unknown. Objectives of the current study were to (a) to investigate differences in glycosaminoglycan, DNA, and soluble collagen levels in mesenchymal stem cell (MSC) treated limbs compared to untreated control limbs utilizing a collagenase model of tendinopathy; (b) compare elastographic features between treatment groups; and (c) determine tissue...
Contrast Enhanced Computed Tomography Findings in 105 Horse Distal Extremities. The poor soft tissue conspicuity of CT can be improved by using intra-arterial CT Angiography (CTA), and intra-articular and intra-bursal contrast enhanced CT (CTAR). This retrospective study describes a combination protocol of CT and CTA of the horse's foot, and CTAR of the distal interphalangeal joint and navicular bursa. It is hypothesized this would provide a comprehensive overview of the range and severity of distal limb pathology. Radiology reports of all horses admitted for distal limb CT over a 5 year period were reviewed. All horses with a complete four stage CT examination and radiol...
Comparison Between Ultrasonographic and Standing Magnetic Resonance Imaging Findings in the Podotrochlear Apparatus of Horses With Foot Pain. This prospective study aimed to blindly compare the ultrasonographic and standing magnetic resonance imaging (sMRI) findings in deep digital flexor tendon (DDFT), navicular bone, and navicular bursa in horses with foot pain, positive digital analgesia, and without definitive radiographic diagnosis. Ultrasonography detected more DDFT abnormalities (32/34 feet vs. 27/34 with sMRI) but identified less palmar navicular abnormalities (23/34 feet vs. 30/34 with sMRI). In suprasesamoidean DDFT lesions, which were mainly dorsally located, changes in echogenicity did not correspond to a particular patt...
Long-term athletic performance in sport horses after desmotomy of the accessory ligament of the deep digital flexor tendon. Outcome after desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) to treat flexural deformity of the distal interphalangeal joint has been reported to be excellent. However, no studies have compared long-term athletic performance of sport horses exposed to desmotomy of the AL-DDFT to that of matched controls. Objective: The objective of this study is to compare long-term athletic performance in sports horses subjected to desmotomy of the AL-DDFT with the performance of matched controls. Methods: This is an observational multicentre retrospective matched cohort study...
Deep digital flexor tendon lesions in the pastern are associated with the presence of distal tendinopathy. Correct diagnosis and characterisation of deep digital flexor tendon (DDFT) lesions in equine athletes allows targeted treatment and improved prognostication. Objective: To assess the prevalence and character of pathological change within the DDFT in the pastern with concurrent tendon injury distally. It is hypothesised that tendon lesions in the pastern will be associated with tendinopathy within the hoof capsule. Methods: Retrospective descriptive case series. Methods: Cases with DDFT lesions in the pastern and magnetic resonance imaging (MRI) or ultrasonography of the foot were evaluated re...
18 Fluorine-fluorodeoxyglucose positron emission tomography for assessment of deep digital flexor tendinopathy: An exploratory study in eight horses with comparison to CT and MRI. Lesions of the deep digital flexor tendon (DDFT) are a cause for foot lameness in horses. Positron emission tomography (PET) could provide valuable information regarding the metabolic activity of these lesions. The aims of this exploratory, prospective, methods comparison study were to assess the ability of fluorine-fluorodeoxyglucose ( F-FDG) PET to detect DDFT lesions and to compare the PET findings with CT and MRI findings. Eight horses with lameness due to pain localized to the front feet were included. Both front limbs of all horses were imaged with F-FDG PET, noncontrast CT, and arteri...
Longitudinal tendon healing assessed with multi-modality advanced imaging and tissue analysis. The range of diagnostic modalities available to evaluate superficial digital flexor tendon (SDFT) injury includes magnetic resonance imaging (MRI), computed tomography (CT) and ultrasonography (US). Direct, comprehensive comparison of multi-modality imaging characteristics to end-point data has not previously been performed using a model of tendinopathy but is required to obtain a better understanding of each modality's diagnostic capabilities. Objective: To compare CT, MRI and US evaluation to outcome measures for histologic, biochemical and biomechanical parameters using an equine surgical m...
Ex vivo mechanical testing of various suture patterns for use in tendon plating. To determine the influence of suture patterns on resistance to gap formation after tendon plating STUDY DESIGN: Ex vivo study SAMPLE POPULATION: Suspensory ligament and superficial and deep digital flexor tendons harvested from 16 neonatal cadaver foal limbs. Methods: Each tendon/ligament from a given limb was randomly assigned to one of three treatment groups consisting of a 7-hole veterinary cuttable plate fixed with alternating simple interrupted, figure-8, or hybrid suture patterns. The constructs were distracted at a rate of 1.0 mm/s to failure, as determined by the formation of a 1 m...
Zonal characterization and differential trilineage potentials of equine intrasynovial deep digital flexor tendon-derived cells. Intrasynovial deep digital flexor tendon (DDFT) injuries occur frequently and are often implicated in cases of navicular disease with poor outcomes and reinjuries. Cell-based approaches to tendon healing are gaining traction in veterinary medicine and ultimately may contribute to improved DDFT healing in horses. However, a better understanding of the innate cellular characteristics of equine DDFT is necessary for developing improved therapeutic strategies. Additionally, fibrocartilaginous, intrasynovial tendons like the DDFT are common sites of injury and share a poor prognosis across species,...
Ex vivo effects of corticosteroids on equine deep digital flexor and navicular fibrocartilage explant cell viability. To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses. Methods: 12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease. Methods: Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or...
Navicular Syndrome-related changes to collagen proportion of different cross-sections of the flexor tendons in equine distal forelimb. The aim of this study was to quantify the distribution of aligned and non-aligned collagen in cross-sections of the superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT) in different levels of the distal forelimb of equines diagnosed with NS (Navicular Syndrome). Sixty equine forelimbs were collected. Was compared two groups (NA, Not affected vs. NS-group) by t-Student. Diagnosis of NS was based on clinical and lameness examination, diagnostic analgesia and radiological findings. The proportion of aligned and non-aligned collagens at 2 levels for the SDFT and 3 levels ...
In vitro Effects of Methylprednisolone Acetate on Equine Deep Digital Flexor Tendon-Derived Cells. Primary deep digital flexor tendon (DDFT) pathologies and those accompanying degenerative changes of navicular bone fibrocartilage are major causes of lameness associated with navicular disease. Intrasynovial corticosteroids are mainstay in the treatment due to the anti-inflammatory effects, but their effect on DDFT cell biosynthesis are unknown. The objective of this study was to investigate the effects of methylprednisolone acetate (MPA) on cells isolated from the dorsal fibrocartilaginous region of forelimb DDFTs (DDFT-derived cells) of 5 horses (aged 11-17 years). Non-adherent aggregate c...
Variation in the MRI signal intensity of naturally occurring equine superficial digital flexor tendinopathies over a 12-month period. Signal intensity (SI) of equine tendinopathies in MRI differs between the superficial digital flexor tendon (SDFT) and the deep digital flexor tendon (DDFT). In DDFT lesions, short tau inversion recovery (STIR) SI decreases earlier than T2-weighted (T2w) SI, while the latter decreases earlier in SDFT lesions, but long-term results using STIR sequences are lacking. Methods: Standing MRI of eight horses with naturally occurring SDFT lesions was performed at the day of treatment as well as 2, 6 and 12 months after treatment. Results: After 12 months, six horses were sound and showed complete reso...
Contrast therapy: Tissue heating and cooling properties within the equine distal limb. Rehabilitation of tendon injuries in horses often involves cryotherapy to reduce inflammation and occasionally tissue heating to increase collagen extensibility. The application of alternating cold and hot (ie contrast therapy) is widely used in human physical therapy; however, its utility in equine rehabilitation is largely unknown. Objective: The objectives of this study were to (a) assess if the equipment could achieve therapeutic tissue temperatures (40°C) at different tissue depths relative to the digital flexor tendons and (b) evaluate the time-temperature profiles during serial heating...
Is the T-ligament a ligament? A histological study in equine cadaver forelimbs. Foot pain is a frequent cause of lameness in horses and can involve multiple structures within the hoof. The T-ligament (an anatomical structure connecting the synovium of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa) is poorly described. Five pairs of equine cadaver distal forelimbs were collected from a slaughterhouse. Sagittal sections (medial, middle and lateral) were obtained and processed with Haematoxylin Eosin Safran, Unna's Orcein, and Picrosirius red stains. Histological assessment revealed that the T-ligament was covered by the surroundi...