The suspensory ligament in horses is a critical component of the equine musculoskeletal system, primarily responsible for supporting the fetlock joint and absorbing shock during movement. This ligament extends from the back of the knee or hock down to the sesamoid bones and continues into the pastern. Injuries to the suspensory ligament, such as strains or tears, are common in performance horses and can significantly affect their mobility and performance. Diagnosis typically involves clinical examination, ultrasonography, or MRI to assess the extent of the injury. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, injury mechanisms, and treatment options related to the suspensory ligament in horses.
Wright IM.The technique of navicular suspensory desmotomy for the treatment of navicular disease is described and the rationale behind its development is discussed. To date 16 horses involved in a clinical evaluation of the technique have been assessed six months after surgery. Thirteen of these horses are able to work without lameness.
Lyons ET, Tolliver SC, Drudge JH, Swerczek TW, Crowe MW.Examination of the ligamentum nuchae for Onchocerca spp was completed in 523 Thoroughbreds (1 to 29 years old) at necropsy in Kentucky during a 13-month period (1984 to 1985). Onchocerca spp were found in 306 (59%) of the horses. Frequencies of this parasite were 3%, 17%, 40%, 43%, and 42% in 1-, 2-, 3-, 4-, and 5-year-old horses, respectively. For 6- to 29-year-old horses, frequency varied from 71% to 100%, except for 26-year-old horses (50%); 87% of the 304 horses examined in the 6- to 29-year-old age groups was infected. The suspensory ligaments and flexor tendons from fetlocks (thoracic li...
Riemersma DJ, Schamhardt HC.The mechanical properties of the deep digital flexor tendon (DDFT), the superficial digital flexor tendon (SDFT) and the suspensory ligament (SL) of the hindlimb of the horse were studied in vitro. The tendons were observed at several morphologically distinct sites. The loaded tendon is homogeneously strained, in spite of large variations in cross-sectional area. Consequently the modulus of elasticity was inversely proportional to the corresponding cross-sectional area and ranged from 738 MPa (megaPascal, N mm-2) to 1398 MPa within the DDFT, from 1000 MPa to 1282 MPa within the SDFT and from 5...
Grabner A, Kraft W, Essich G, Hänichen T.Cases of enzootic calcinosis in breeding mares in a Southwest German highland area are reported. The symptoms increased in the latter part of summer and existed in disturbances of movement, moderate kyphosis, sensitivity to palpation in the flexor tendons and, especially, the suspensory ligament, weight loss in spite of good food intake during summer-time and painful costal percussion; less clinical signs of renal and cardiac disorders were established. The sickness was caused by a high percentage of Trisetum flavescens in the feeding plants.
Verschooten F, Gasthuys F, De Moor A.An experimental and clinical study to investigate the aetiology of distal splint bone fractures is described. In vitro, extension of the fetlock did not appear to alter the position of the distal ends of the splint bones, although tension in the interosseous tendons increased. Flexion of the fetlock resulted in slight outward displacement of the distal ends of the splint bones. It is suggested that concurrent desmitis of the suspensory ligament can cause movement of the ends of the splint bones thus predisposing to a fatigue fracture. In a clinical study of 87 horses, 114 splint bone fractures...
Bowman KF, Leitch M, Nunamaker DM, Fackelman GE, Tate LP, Park MI, Boles CL, Raker CW.A total of 19 Thoroughbred horses were treated for traumatic disruption of the suspensory apparatus, using either external support of the injured limb, removal of fractured proximal sesamoid bone fragments, metacarpophalangeal arthrodesis, compression screw fixation of the fractured proximal sesamoid bones, application of a cast-brace attached to a transfixation pin inserted through the third metacarpal bone, or combinations thereof. Major complications during the treatment of traumatic disruption of the suspensory apparatus were infection (9 of 19 horses, 47%), large cast sores (10 of 14 trea...
Lochner FK, Milne DW, Mills EJ, Groom JJ.Strains gauges were applied to the superficial flexor tendon, deep flexor tendon, and suspensory ligament of sound adult horses. Maximum tendon strain occurred during full weight bearing while walking, when the forelimb was perpendicular to the group surface. There was decrease in tendon strain with increase in hoof angle for the deep digital flexor, but no change in tendon strain for the superficial digital flexor and suspensory ligament with changing hoof angle. At physiologic rates of strain, tendons were able to withstand large loads without yielding. Load strain curves developed in vitro ...
Bramlage LR, Gabel AA, Hackett RP.Five horses with avulsion fractures of the proximal origin of the suspensory ligament were examined for lameness. The horses in the series each had lameness of acute onset; four were severely lame, and one was moderately lame. The condition was difficult to diagnose because commonly used local anesthetic blocks did not result in improvement during the routine examination. Local infiltration of the area with local anesthetic returned the horses to soundness. After a period of rest, varying from a few weeks in the acute injury to 6 months in the chronic injuries, the horses were returned to raci...
Wheat JD, Pascoe JR.Problems involving the management of acute traumatic rupture of the equine suspensory apparatus include loss of blood flow to the foot, proper immobilization, and pressure sores from casts. A technique utilizing a board splinting device attached to the affected limb at the toe and subsequent corrective shoe support provides immobilization, prevents dropping of the fetlock, can be applied to the standing animal, and allows frequent changing of the bandages, if necessary.
Parry DA, Craig AS, Barnes GR.A study has been made of the ultrastructural organization of the collagen fibrils and elastic fibres in tendons and ligaments from horses of ages ranging from 2 months premature to 19 years. Diameter distributions of the collagen fibrils in the common digital extensor tendon, the superficial flexor tendon and the suspensory ligament are unimodal in the foetal tissue and at birth, and at these stages of development the three collagenous tissues are virtually indistinguishable. However, at maturity, the ligament and flexor tendon have bimodal distributions similar to that found for rat-tail tend...
Jones RD, Fessler JF.ALTHOUGH METACARPAL TI-IV and metatarsal II-IV (MC II-IV, MT II-IV) fractures are frequent in horses and surgical intervention routine, a review of the current literature revealed little information about this subject. The authors have found only two complete accounts of this problem (1, 6). The incidence of suspensory desmitis has been previously reported (3), but we find no previous correla-tion of MC II-IV, MT II-IV fractures with suspensory, desmitis. On these bases, a re-trospective study was conducted. At Purdue University from 1967 through 1974, 50 Standardbred horses underwent sur-gery...
Knudsen O.The paper briefly describes the percutaneous tendon splitting operation as performed in general practice and evaluates its effectiveness on the basis of races run during a 2 year follow-up period. The results are compared with similar figures for normal Standardbred trotters. A higher percentage of horses subjected to splitting of the suspensory ligament failed to remain sound long enough to run more than 10 races during the follow-up period. The percentage of horses returning to racing whose superficial flexor was operated upon was somewhat lower than the control group.
Nixon AJ, Cummings JF.Serial sections of bone and soft tissue from the metacarpophalangeal joints of 2 mature and 2 immature horses were evaluated for substance P immunoreactive sensory nerve fibers. Formalin-fixed specimens were sectioned, either nondemineralized or demineralized with formic acid or EDTA. Rabbit antiserum to substance P (SP) was used in the streptavidin-biotin-peroxidase complex method for immunolocalization of SP antigen, and staining with 3,3'-diaminobenzidine was used for permanent identification of SP fibers. Abundant sensory nerve fibers were identified in the joint capsule, synovial membrane...
Sullivan HM, Barrett MF, Zhou T, Kawcak CE.Ultrasound remains a mainstay in proximal suspensory ligament (PSL) evaluation. Despite recent improvements facilitating earlier diagnosis/treatment, needs exist for (1) characterization of normal ultrasonographic PSL cross-sectional area (CSA) in specific breeds/disciplines, (2) improved detection of early/subtle changes in the PSL, and (3) an understanding of suspensory ligament (SL) morphology change from work-related stress. The objectives of this study were to establish normal PSL CSA in Quarter Horses (QH) used for cutting via angle contrast ultrasonography, ultrasonographically monitor ...
Waselau M, Sutter WW, Genovese RL, Bertone AL.To determine outcome of Standardbred racehorses with moderate to severe midbody suspensory ligament desmitis (MSD) treated by means of ultrasound-guided intralesional injection of a single dose of platelet-rich plasma (PRP) followed by a program of gradually increased exercise. Methods: Nonrandomized clinical trial. Methods: 9 Standardbred racehorses. Methods: Following injection of PRP, horses were allowed a controlled, gradual return to exercise. Race records for the year prior to injury and for 3 consecutive years after horses returned to racing were reviewed. For comparison purposes, race ...
Whitlock D, Garcia TC, Vallance SA, Stover SM.The specific biomechanical circumstances that induce excessive superficial digital flexor tendon (SDFT) strain in horses are unknown. Objective: Carpal joint hyperextension during axial limb loading during the middle of stance disproportionately enhances SDFT strains compared to suspensory ligament (SL) strains. Methods: Superficial digital flexor tendon and SL strains were measured in 7 cadaver limbs during in vitro loading that maintained carpal extension or allowed carpal hyperextension by constraining, or allowing rotation of, the radius during loading conditions that simulated the middle ...
Sidhu ABS, Rosanowski SM, Davis AM, Griffith JF, Robinson P.To quantitate the iatrogenic injury associated with deep plantar metatarsal fasciotomy performed with Metzenbaum scissors compared with a Y-shaped fasciotome. Methods: Experimental ex vivo surgical study. Methods: Cadaveric hind limbs (n = 20) from 10 sound thoroughbred racehorses. Methods: A plantar metatarsal fasciotomy was performed, extending from the proximal extent of the deep metatarsal fascia, distally. Hind limbs were randomly assigned to 2 groups, undergoing fasciotomy with straight Metzenbaum scissors (n = 10) or a Y-shaped fasciotome (n = 10). Magnetic resonance imaging...
Keg PR, Schamhardt HC, van Weeren PR, Barneveld A.Controversy exists with respect to the innervation of the suspensory ligament (SL) in the fore limb of the horse. It is uncertain whether this structure is exclusively innervated by branches of the ulnar nerve or also to some extent by median nerve branches. Ground Reaction Forces (GRF) were determined in horses before and after the induction of a tendonitis in the lateral branch of the SL by the injection of collagenase, and before and after a high palmar and an ulnar block respectively. The high palmar block succeeded in bringing all GRF variables back to their original values which the ulna...
Frontiers in geneticsAugust 14, 2023
Volume 14 1201628 doi: 10.3389/fgene.2023.1201628
Momen M, Brauer K, Patterson MM, Sample SJ, Binversie EE, Davis BW, Cothran EG, Rosa GJM, Brounts SH, Muir P. Spontaneous rupture of tendons and ligaments is common in several species including humans. In horses, degenerative suspensory ligament desmitis (DSLD) is an important acquired idiopathic disease of a major energy-storing tendon-like structure. DSLD risk is increased in several breeds, including the Peruvian Horse. Affected horses have often been used for breeding before the disease is apparent. Breed predisposition suggests a substantial genetic contribution, but heritability and genetic architecture of DSLD have not been determined. To identify genomic regions associated with DSLD, we recr...
Major MD, Grant BD, White KK, Ratzlaff MH, Gallina AM, Donati RM.The suspensory apparatus of one forelimb was surgically disrupted in six adult horses by transecting the distal sesamoidean ligaments. A double-braided prosthetic ligament made of aramid yarn was installed to support the flexor surface of the metacarpophalangeal joint. The prosthesis was routed through tunnels in the third metacarpal bone and proximal phalanx, and secured to bone with screws. Evaluation by radiography, synovial fluid analysis, cinematography, and dynamography was performed before surgery and at weeks 16 and 30. Supracondylar cortical lysis and periosteal proliferation were obs...
Müller EMT, Vanderperren K, Merle R, Rheinfeld S, Leelamankong P, Lischer CJ, Ehrle A.The objective of this retrospective, observational, controlled study was to evaluate bone and soft tissue window CT images of the proximoplantar metatarsus III region in twenty horses with pain localized to the proximal suspensory ligament (PSL) and 20 horses with findings nonrelated to tarsal pain. All horses underwent CT and radiographic examination. Images were reviewed by three independent observers who graded the severity and localization of findings. Bone-related categories as well as soft tissue-related categories were evaluated. For the comparison of imaging findings in horses with and...
Auth AK, Hinnigan GJ, Smith MA, Owen KR.Low-field, magnetic resonance imaging (MRI) is an advanced imaging modality widely used to diagnose distal limb pathology in horses, but there are limited data regarding lesion distribution within the metacarpo/metatarsophalangeal joint (MCP/MTPJ) region in lame nonracehorses. The aim of this study was to describe the low-field MRI findings and lesion distribution in nonracehorses with MCP/MTPJ region pain. Clinical records from horses undergoing MRI of the MCP/MTPJ region between July 2016 and March 2023 were reviewed. Horses were included if pain causing lameness was localized to this region...
Carlier S, Depuydt E, Suls M, Bocqué C, Thys J, Vandenberghe A, Martens A, Saunders J, Hellmann K, Braun G, Beerts C, Spaas JH.Mesenchymal stem cells are an innovative therapeutic for various equine orthopaedic diseases, including soft tissue injuries. Objective: To evaluate the safety and efficacy of tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. Methods: Multicentre, blinded, randomised, placebo-controlled clinical trial. Methods: One hundred client-owned horses with SDFT and SL injuries were randomised to receive an intralesional tpMSC (66) or saline (34) in...
Dancot M, Joostens Z, Audigié F, Busoni V.Knowledge of normal radiographic appearance is essential to avoid misinterpretation of radiographs. This study aimed to assess the computed tomographic (CT) appearance of the plantar surface of the proximal metatarsus and evaluate the influence of the radiographic angle on the trabecular/cortical interface of the proximal plantar metatarsal cortex on lateromedial and slightly oblique radiographs. Unassigned: Eight hindlimbs were collected from six horses with no known history of lameness and euthanized for reasons unrelated to the study. Limbs underwent computed tomographic (CT) and radiograph...
Ratcliffe TOC, Robinson P, Rosanowski SM.To evaluate and compare the prognosis for Thoroughbred racehorses to return to galloping and racing with injuries to the palmaroproximal metacarpus diagnosed with MRI. Methods: 29 flat racing Thoroughbreds at the Hong Kong Jockey Club that underwent MRI between 2014 and 2022. Methods: Clinical, radiographic, ultrasonographic, and MRI reports were collected from veterinary clinical records, and these were combined with training and racing data. Horses were categorized on the basis of MRI diagnosis: (1) proximal suspensory ligament (PSL) involvement only, (2) PSL and concurrent proximal third me...
Orozco Lopez D, Mochal-King C, Fontenot R, O'Shea CM.To determine the ability to completely transect the equine accessory ligament of the deep digital flexor tendon (AL-DDFT) via an ultrasonographically-guided, percutaneous looped thread desmotomy using FiberWire suture as a cutting device. Methods: Ex-vivo study. Methods: A total of 24 normal equine distal forelimb specimens. Methods: Under ultrasonographic guidance, a Jamshidi needle was placed between the suspensory ligament and the AL-DDFT, and between the AL-DDFT and the deep digital flexor tendon, through two stab incisions. FiberWire suture was fed through the needle and looped around the...
Carlier S, Depuydt E, Van Hecke L, Martens A, Saunders J, Spaas JH.Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. Unassigned: The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. Unassigned: The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte re...
Williams MR, Crisman E, Taylor BM.To describe the microvascular anatomy of the equine hind limb suspensory ligament. Methods: 18 hind limbs harvested from 9 adult horses euthanized for reasons unrelated to lameness. Methods: A catheter was placed in the transected cranial tibial artery at the level of the mid-distal tibia for each hind limb and used to inject 120 to 150 mL of contrast medium (2 limbs) to identify principal vasculature using contrast-enhanced CT or India ink (11 limbs) to identify microvasculature using the Spalteholz tissue-clearing technique. Routine histologic evaluation was performed on transverse sections ...
