Topic:Ligaments
Ligaments in horses are fibrous connective tissues that connect bones to other bones, providing stability and support to the skeletal structure. These structures are integral to maintaining joint function and facilitating movement. In equine anatomy, ligaments are involved in various functions, including supporting the limbs and allowing for efficient locomotion. Common ligaments in horses include the suspensory ligament, which plays a significant role in supporting the fetlock joint, and the nuchal ligament, which supports the head and neck. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, injury mechanisms, and rehabilitation of ligaments in horses.
Magnetic resonance imaging features of oblique and straight distal sesamoidean desmitis in 27 horses. Injury to the oblique and straight distal sesamoidean ligaments is becoming recognized as a more common cause of lameness in horses than was previously thought. The purpose of this study was to review the magnetic resonance (MR) imaging findings of 27 horses affected with desmitis of the oblique and/or straight distal sesamoidean ligament and determine long-term prognosis for horses with this diagnosis. Imaging was performed with horses in right lateral recumbency in a high-field 1 T magnet. All horses had lameness localized to the digit or metacarpophalangeal/metatarsophalangeal joint region ...
Cell phenotypic variation in normal and damaged tendons. Injuries to tendons are common in both human athletes as well as in animals, such as the horse, which are used for competitive purposes. Furthermore, such injuries are also increasing in prevalence in the ageing, sedentary population. Tendon diseases often respond poorly to treatment and require lengthy periods of rehabilitation. The tendon has a unique extracellular matrix, which has developed to withstand the mechanical demands of such tensile-load bearing structures. Following injury, any repair process is inadequate and results in tissue that is distinct from original tendon tissue. There ...
Metacarpophalangeal collateral ligament reconstruction using small intestinal submucosa in an equine model. Xenogeneic porcine small intestinal submucosa (SIS) is a natural, biodegradable matrix that has been successfully used as a scaffold for repair of tissue defects. The goal of this study was to compare a collateral ligament transection surgically reconstructed with an anchored SIS ligament to a sham-operated control procedure for the correction of joint laxity using an equine model. Ten metacarpophalangeal joints from 10 horses had complete transection of the lateral collateral ligament. In 6 horses, the collateral ligament was reconstructed with a multilaminate strip of SIS anchored with screw...
Sonographic anatomy of the palmarodistal aspect of the equine digit. Although ultrasonography is widely used in equine orthopedics, its use in the distal portion of the digit is still limited. The purpose of this descriptive study was to document the normal ultrasonographic appearance of the palmarodistal aspect of the digital area imaged between the bulbs of the heels. Ultrasonographic images were obtained with a 7.5 MHz microconvex transducer in 10 fresh equine cadaver forelimbs and five soundhorses. Sagittal, parasagittal, and transverse images were obtained from the proximal aspect of the middle phalanx to the distal sesamoid bone. Anatomic sections were ob...
Association of type of sport and performance level with anatomical site of orthopaedic injury diagnosis. Although anecdotal reports of increased orthopaedic injury risk in equine sports exist, there is little scientific evidence to support this. Objective: To test whether horses undertaking a single competitive sport have increased risk of specific injuries compared to those used for general purpose riding (GP); and whether injury type varies with sport category and performance level. Methods: Data from 1069 records of horses undergoing orthopaedic evaluation (1998-2003) and meeting inclusion criteria were reviewed. Sport category (GP, showjumping, dressage, eventing, racing), level (nonelite or ...
Movement between the equine ilium and sacrum: in vivo and in vitro studies. Sacroiliac disease (SID) is an important cause of loss of performance in horses, yet little is known about the biomechanics of movement of the sacroiliac joint (SIJ). Objective: (a) To document the presence of equine SIJ motion by measuring the change in cross-sectional area (CSA) of the dorsal portion of the dorsal sacroiliac ligament (DSIL) during application of manual forces to the pelvis, and to ascertain if this varied between horses with SID and normal horses; (b) To determine the amount and direction of motion available at the equine SIJ using 3-D orientation sensors, and how motion is ...
Asymmetric signal intensity in normal collateral ligaments of the distal interphalangeal joint in horses with a low-field MRI system due to the magic angle effect. Increased signal intensity in one of the collateral ligaments of the distal interphalangeal (DIP) joint of sound horses in images acquired using a low-field magnet with vertical orientation of the magnetic field was investigated as a possible manifestation of the magic angle effect. Three isolated equine digits were imaged using the following pulse sequences: (1) spin echo TI, (2) turbo spin echo proton density and T2, and (3) 3D gradient echo T1, in different positions by mildly changing the orientation of the long axis of the digit, in the dorsal plane, relative to the magnetic field. The si...
Ultrasonographic evaluation of the supraspinous ligament in a series of ridden and unridden horses and horses with unrelated back pathology. Injury to the supraspinous ligament (SSL) is reported to cause back pain in the horse. The diagnosis is based on clinical examination and confirmed by ultrasonographic examination. The ultrasonographic appearance of the supraspinous ligament has been well described, but there are few studies that correlate ultrasonographic findings with clinical pain and/or pathology. This preliminary study aims to test the hypothesis that unridden horses (n = 13) have a significantly reduced frequency of occurrence of ultrasonographic changes of the SSL consistent with a diagnosis of desmitis when compared to...
Comparative anatomy of the meniscofemoral ligament in humans and some domestic mammals. The purpose of this study was to investigate the presence, position and relative sizes of the meniscofemoral ligaments (MFL) in three quadrupeds and humans and relate these to the caudal slope of the lateral tibial plateau. Canine, ovine and equine stifles and human knees were dissected to identify the presence of MFLs, their obliquity in relation to the caudal cruciate ligaments (CCL), the relative size and shape of the MFLs compared with the CCL, the points of femoral attachment of the MFLs and CCL, and the distance between the MFLs and CCL at their midpoints. The lateral tibial condyle was ...
Sensitivity of an equine distal limb model to perturbations in tendon paths, origins and insertions. As equine musculoskeletal models become common, it is important to determine their sensitivity to the simplifications used. A subject-specific distal forelimb model was created using bones extracted from CT scans to examine movement from in-vivo invasive-marker motion capture. The movements of the sesamoid bones were simulated using the constraints of maintaining an isometric virtual ligament and maintaining contact between the appropriate articular surfaces, creating a variable moment arm for the tendons. The simulation of the proximal sesamoid bones was compared to movement recorded in-vitro...
Intraarterial contrast-enhanced computed tomography of the equine distal extremity. A technique for regional delivery of contrast medium to the foot of the horse to increase the diagnostic utility of computed tomography (CT) for the characterization of soft tissue structures within the hoof capsule was developed. An intraarterial catheter was placed under ultrasound guidance into the medial palmar artery at the level of the carpus to facilitate a steady-state infusion of iodinated contrast medium. Two 5 mm collimated contiguous acquisition CT scans were performed in 10 horses without lameness or radiographic evidence of distal sesamoid bone degeneration. CT examination was pe...
Image fusion of computed tomographic and magnetic resonance images for the development of a three-dimensional musculoskeletal model of the equine forelimb. Biomechanical models that compute the lengths and forces of muscle-tendon units are broadly applicable to the study of factors that promote injury and the planning and effects of orthopedic surgical procedures in equine athletes. A three-dimensional (3D) generic musculoskeletal model of the equine forelimb comprised of bony segment, muscle-tendon, and ligament information, was developed based on high-resolution computed tomographic (CT) and T1-weighted magnetic resonance (MR) images from an isolated forelimb of a Thoroughbred racehorse. Image fusion was achieved through coregistration of CT an...
MRI and CT diagnosis of acute desmopathy of the lateral collateral sesmoidean (navicular) ligament and long-term outcome in a horse. Clinical, magnetic resonance imaging (MRI) and computed tomography (CT) findings of acute desmopathy of the lateral collateral sesmoidean (navicular) ligament (CSL) in a 13-year-old Hanoverian mare are presented. On admission to the clinic the horse showed a grade 5/6 left front-limb lameness at the walk, pain on coffin joint manipulation, and coffin joint effusion. Despite a positive palmar digital nerve block, radiographs and ultrasonography did not indicate reasons for the severe clinical signs. However, MRI revealed damage to the CSL and bone marrow oedema of the navicular bone (NB), where...
Collagen fiber architecture of the periodontal ligament in equine cheek teeth. The objective of this study was to examine the spatial arrangement of the fiber apparatus of the equine periodontium which is supposed to meet two contrary requirements: (1) to attach the tooth firmly and elastically to the alveolar bone; and, to be appropriately remodeled and reconstructed in order to facilitate the prolonged eruption of the tooth. Specimens of periodontal ligament were obtained from the buccal and lingual/palatal aspects of the first molars from the maxilla and mandible of 12 horses. The animals were assigned to three age groups. Histological sections were prepared from thre...
Outcome of desmoplasty and fasciotomy for desmitis involving the origin of the suspensory ligament in horses: 27 cases (1995-2004). To determine outcome of percutaneous ultrasound-guided desmoplasty with simultaneous fasciotomy for proximal suspensory desmitis (ie, desmitis of the origin of the suspensory ligament) in horses that have not responded to stall rest. Methods: Retrospective case series. Methods: 27 horses. Methods: Medical records of horses with proximal suspensory desmitis treated by means of desmoplasty with fasciotomy were reviewed. Follow-up information was obtained through telephone conversations with owners and trainers of the horses or by examination of horses at the hospital. Results: 23 of the 27 (85%)...
Ultrasonographic technique and normal anatomic features of the sacroiliac region in horses. The purpose of this study was to establish the normal percutaneous ultrasonographic appearance of anatomic structures within the equine sacroiliac region. Percutaneous ultrasonography was performed in a cranial-to-caudal direction in 10 normal adult live horses. The following structures were examined in detail: supraspinous ligament, lumbar and sacral spinous processes, thoracolumbar fascia and its caudal extension, tubera sacralia, ilial wings, dorsal and lateral portions of the dorsal sacroiliac ligaments, lateral part of the sacrum, and the lateral sacral crest. After ultrasonography, all a...
Collateral ligaments of the distal sesamoid bone in the digit of Equus: re-evaluating midstance function. The distal forelimb of the horse has a complex array of ligaments that play a critical role in determining function of the digit and are often associated with the initiation of foot pathologies. The collateral ligaments of the distal sesamoid bone (CLDS) play an important role in digit stabilization near the end of foot contact and there is also limited evidence to suggest that the CLDS stabilize the proximal interphalangeal joint (PIPJ) during weight bearing. By virtue of their anatomical attachments where the ligaments pass dorsal to the axis of rotation of the PIPJ, it is reasonable to assu...
Direct adenovirus-mediated IGF-I gene transduction of synovium induces persisting synovial fluid IGF-I ligand elevations. Insulin-like growth factor-I (IGF-I) is one of the most influential growth factors in cartilage repair. Maintenance of adequate IGF-I levels after articular repair procedures is complicated by the short biological half-life of IGF-I in vivo. This study investigated the potential for more prolonged IGF-I delivery through direct adenoviral mediated transduction of synovial tissues in the metacarpophalangeal (MCP) joints of horses. The use of a large animal model provided a structurally similar and metabolically relevant corollary to the human knee. The complete IGF-I coding sequence was packaged...
Degenerative suspensory ligament desmitis as a systemic disorder characterized by proteoglycan accumulation. Degenerative suspensory ligament desmitis (DSLD) is a debilitating disorder thought to be limited to suspensory ligaments of Peruvian Pasos, Peruvian Paso crosses, Arabians, American Saddlebreds, American Quarter Horses, Thoroughbreds, and some European breeds. It frequently leads to persistent, incurable lameness and need to euthanize affected horses. The pathogenesis remains unclear, though the disease appears to run in families. Treatment and prevention are empirical and supportive, and not effective in halting the progression of the disease. Presently, the presumptive diagnosis of DSLD is ...
Anabolic effects of acellular bone marrow, platelet rich plasma, and serum on equine suspensory ligament fibroblasts in vitro. The purpose of this study was to investigate the response of suspensory ligament fibroblasts (SLF) to in vitro stimulation using acellular bone marrow (ABM), platelet rich plasma (in vitro PRP), and serum as potential treatment modalities for suspensory desmitis. Blood, bone marrow, and suspensory ligaments were collected from five horses. SLF were harvested, grown until confluent, and stimulated with various concentrations of ABM, PRP, equine serum, foetal bovine serum, and medium (control). The responses to the treatments were assessed using a combination of radio-labeling for total protein ...
Histomorphologic evaluation of extracorporeal shock wave therapy of the fourth metatarsal bone and the origin of the suspensory ligament in horses without lameness. To determine via histologic examination and scintigraphy the effect of focused extracorporeal shock wave therapy (ESWT) on normal bone and the bone-ligament interface in horses. Methods: 6 horses without lameness. Methods: Origins of the suspensory ligament at the metacarpus (35-mm probe depth) and fourth metatarsal bone (5-mm probe depth) were treated twice (days 0 and 16) with 2,000 shocks (energy flux density, 0.15 mJ/mm2). One forelimb and 1 hind limb were randomly treated, and the contralateral limbs served as nontreated controls. Bone scans were performed on days -1 (before ESWT), 3, 16,...
[Disorders of the origin of the suspensory ligament in the horse: a diagnostic challenge]. Lameness in horses due to pain originating from the proximal metacarpal/metatarsal region remains a diagnostic challenge. In cases of obvious lameness the pain can be localised to this region by diagnostic anaesthesia. Because a variety of disorders can cause lameness in this region different imaging modalities including radiography, ultrasonography and scintigraphy should be used to arrive at an accurate diagnosis. Even though a precise anatomic-pathologic diagnosis can still be an enigma, because not only bone and joints, but also soft tissue structures including the proximal suspensory liga...
Gentamicin concentrations in synovial fluid and joint tissues during intravenous administration or continuous intra-articular infusion of the tarsocrural joint of clinically normal horses. To compare gentamicin concentrations achieved in synovial fluid and joint tissues during IV administration and continuous intra-articular (IA) infusion of the tarsocrural joint in horses. Methods: 18 horses with clinically normal tarsocrural joints. Methods: Horses were assigned to 3 groups (6 horses/group) and administered gentamicin (6.6 mg/kg, IV, q 24 h for 4 days; group 1), a continuous IA infusion of gentamicin into the tarsocrural joint (50 mg/h for 73 hours; group 2), or both treatments (group 3). Serum, synovial fluid, and joint tissue samples were collected for measurement of gentami...
Expression of insulin-like growth factor binding proteins in healing tendon lesions. he treatment of overuse tendon injuries with exogenous growth factors such as insulin-like growth factor-I (IGF-I) may facilitate an improved return to sustained athletic function. The biological effects of IGF-I are exerted under the control of a complex of IGF receptors, binding proteins, and proteases. This IGF system includes a family of six structurally related high-affinity IGF binding proteins (IGFBPs) that protect IGF-I from local proteases and restrict access of IGF-I to its receptor. This study describes the expression of the IGFBPs in flexor tendon after acute injury and during heal...
How does magnetic resonance imaging represent histologic findings in the equine digit? Magnetic resonance (MR) imaging is increasingly used in the diagnosis of equine foot pain, but improved understanding of how MR images represent tissue-level changes in the equine foot is required. We hypothesized that alterations in signal intensity and tissue contour would represent changes in tissue structure detected using histologic evaluation. The study objectives were to determine the significance of MR signal alterations in feet from horses with and without lameness, by comparison with histopathologic changes. Fifty-one cadaver feet from horses with a history of lameness improved by pa...
Histopathology in horses with chronic palmar foot pain and age-matched controls. Part 2: The deep digital flexor tendon. Causes of palmar foot pain and the aetiopathogenesis of navicular disease remain poorly understood, despite the high incidence of foot-related lameness. Objective: Abnormalities of the deep digital flexor tendon (DDFT) may contribute to palmar foot pain; ageing degenerative changes may be seen in horses free from lameness; and horses with lameness are likely to have a greater severity of abnormalities than age-matched horses with no history of foot pain. Methods: Feet were selected from horses with a history of uni- or bilateral forelimb lameness of at least 2 months' duration. Histology of th...
A mechanical study of ligature security of commercially available pre-tied ligatures versus hand tied ligatures for use in equine laparoscopy. To determine a hand-tied ligature knot configuration, suture size, and suture type that would be an acceptable substitute to commercially available ligature knots for use in equine laparoscopic surgery. Methods: Three-factor ANOVA with the fixed effects being suture type, suture size, and knot type. The dependent variable was ligature security (load to failure). Methods: Commercially available Endoloop and 4 hand-tied slipknot ligatures were compared with a 4-layer square knot. The hand tied ligature knots tested were the 4S modified Roeder knot, the Brooks knot, the modified Roeder knot, and ...