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.
Nagy A, Dyson S.While low-field magnetic resonance (MR) images can provide useful information in the investigation of proximal metacarpal region pain, an in-depth knowledge of anatomy and comparison with more detailed high-field images are essential to understand the meaning of different signal intensities within tissues. This anatomic description is based on low-field and high-field MR examination of 30 cadaver metacarpal regions of mature horses with no history of carpal or proximal metacarpal pain. Normal MR anatomy is described and is illustrated by high-field and low-field MR images in transverse, sagitt...
Pauwels FE, Schumacher J, Mayhew IG, Van Sickle DC.Neurectomy of the deep branch of the right lateral plantar nerve was performed on a single healthy mature horse. Six weeks after surgery, the horse was subjected to euthanasia and both hind suspensory ligaments harvested. The cross sectional area of the muscular part of the proximal part of the suspensory ligament was measured and assessed for morphological abnormalities in a blinded fashion. There was a clear difference in cross sectional area of the muscular part between treated and control ligament and there was profound neurogenic atrophy of the muscular fibres in the treated ligament.
Bosch G, de Mos M, van Binsbergen R, van Schie HT, van de Lest CH, van Weeren PR.Extracorporeal shock wave therapy (ESWT) is frequently used in equine practice, but little is known about its biological action. Objective: To study the effects of ESWT on matrix structure and gene expression levels in normal, physiologically loaded tendinous structures in ponies. Methods: Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor tendon (SDFT) 6 weeks prior to sample taki...
Launois MT, Vandeweerd JM, Perrin RA, Brogniez L, Desbrosse FG, Clegg PD.3 horses with lameness localized to the proximal aspect of the metacarpus or metatarsus. Results: All horses had evidence of problems that originated from the proximal aspect of the suspensory ligament (PASL), including signs of pain on palpation, positive results of diagnostic nerve blocks, ultrasonographic detection of enlargement and diffuse areas of reduced echogenicity in the proximal region of insertion of the ligament, and radiographic detection of increased mineral opacity in the proximal aspect of the metacarpus or metatarsus. Desmitis of the PASL was diagnosed in each horse; however,...
Birch HL, Wilson AM, Goodship AE.This study explores the hypothesis that high-intensity exercise induces degenerative changes in the injury-prone equine superficial digital flexor tendon (SDFT), but not in the rarely injured common digital extensor tendon (CDET). The horse represents a large-animal model that is applicable to human tendon and ligament physiology and pathology. Twelve age-matched female horses undertook galloping exercise three times a week with trotting exercise on alternative days (high-intensity group, n = 6) or only walking exercise (low-intensity group, n = 6) for 18 mo. The SDFT, suspensory ligament, dee...
Tóth F, Schumacher J, Schramme M, Holder T, Adair HS, Donnell RL.To describe pathologic changes in the deep branch of the lateral plantar nerve (DBLPN) of horses determined to be lame because of proximal suspensory desmitis (PSD), and to report the outcome after treatment by excision of a segment of the horses' DBLPN. Methods: Retrospective case series. Methods: Adult horses (n=16). Methods: Horses determined to be lame on one or both pelvic limbs because of PSD were treated by excision of a segment of the DBLPN, and 30 nerves were examined histologically. Owners were contacted to obtain information about the horses >or=6 months after surgery. Results: H...
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 ...
Carpenter RS, Galuppo LD, Simpson EL, Dowd JP.To report use of a locking compression plate (LCP) for fetlock arthrodesis in Thoroughbred racehorses after catastrophic disruption of the suspensory apparatus. Methods: Retrospective case study. Methods: Racing Thoroughbreds (n=6) with a catastrophic breakdown injury of the suspensory apparatus. Methods: Medical records (2004-2006) of horses that had fetlock arthrodesis using an LCP were reviewed. Preoperative recorded variables were: age, gender, affected limb, injury type and occurrence, limb support used and time to surgery. Recorded surgical variables were: implants used and cost, surgery...
Agut A, Martínez ML, Sánchez-Valverde MA, Soler M, Rodríguez MJ.The objectives of this study were to establish normal values for relative echogenicity (RE) and cross-sectional area (CSA) of the flexor tendons and ligaments of the metacarpal region of Purebred Spanish horses (PBSH), and to determine the effect of body mass index (BMI), age, sex and forelimb on these variables. Transverse ultrasonographic images were obtained using 20 normal PBSH (10 females, 10 males; 2-25 years of age; BMI 132.04-152.25; not in training). The images were digitised and values for CSA and RE were determined for each structure. The suspensory ligament was the most echogenic a...
Imboden I, Waldern NM, Wiestner T, Lischer CJ, Ueltschi G, Weishaupt MA.Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects...
Argüelles D, Carmona JU, Climent F, Muñoz E, Prades M.Two horses with acute tendinopathy of a superficial digital flexor tendon (SDFT) and three horses with chronic proximal desmitis of the suspensory ligament (PDSL) were treated by injecting autologous concentrates of their platelets into the lesions. The lesions were monitored ultrasonographically and clinically. There were significant ultrasonographic and clinical improvements in the two horses with SDFT, but no ultrasonographic improvements in the horses with PDSL; however, they improved clinically and became less lame. All the horses had returned to their pre-injury level of performance by s...
Hughes TK, Eliashar E, Smith RK.To examine the anatomic relationship of the deep branch of the lateral plantar nerve (DBLPN) with structures of the proximal metatarsal region, and to define the anatomic location of a solution injected using a single injection technique for diagnostic analgesia of the proximal suspensory ligament (PSL). Methods: Descriptive study. Methods: Cadaveric equine pelvic limbs (n=29). Methods: The proximal metatarsal region of both pelvic limbs (n=5 horses, 10 limbs) was dissected and measurements were made of anatomic structures relative to the head of the 4th metatarsal bone (HMT4). A single inject...
Butcher MT, Hermanson JW, Ducharme NG, Mitchell LM, Soderholm LV, Bertram JE.Racing and training related lesions of the forelimb superficial digital flexor tendon are a common career ending injury to racehorses but aetiology and/or predisposing causes of the injury are not completely understood. Objective: Although the injury takes place within the tendon, the lesion must be considered within the context of the function of the complete suspensory system of the distal limb, including the associated muscles. Methods: Both muscle and tendon function were investigated in vivo using implanted strain gauges in 3 Thoroughbred horses walking, trotting and cantering on a motori...
Brokken MT, Schneider RK, Sampson SN, Tucker RL, Gavin PR, Ho CP.Magnetic resonance (MR) imaging abnormalities in horses with lameness localized to the proximal metacarpal or metatarsal region have not been described. To accomplish that, the medical records of 45 horses evaluated with MR imaging that had lameness localized to either the proximal metacarpal or metatarsal region were reviewed. Abnormalities observed in the proximal suspensory ligament or the accessory ligament of the deep digital flexor tendon included abnormal high signal, enlargement, or alteration in shape. Twenty-three horses had proximal suspensory ligament desmitis (13 hindlimb, 10 fore...
Bosch G, Lin YL, van Schie HT, van De Lest CH, Barneveld A, van Weeren PR.Extracorporeal shockwave therapy (ESWT) has recently been introduced as a new therapy for tendon injuries in horses, but little is known about the basic mechanism of action of this therapy. Objective: To study the effect of ESWT on biochemical parameters and tenocyte metabolism of normal tendinous structures in ponies. Methods: Six Shetland ponies, free of lameness and with ultrasonographically normal flexor and extensor tendons and suspensory ligaments (SL), were used. ESWT was applied at the origin of the suspensory ligament and the mid-metacarpal region of the superficial digital flexor ten...
Lawson SE, Chateau H, Pourcelot P, Denoix JM, Crevier-Denoix N.The sagittal alteration of hoof balance is a common intervention in horses, with corrective shoeing being one of the most frequently applied methods of managing tendonitis. However, the effect of toe or heel elevation on tendon strains is poorly understood. This study aimed to examine the effect of toe and heel wedges on the superficial digital flexor tendon, deep digital flexor tendon, and the third interosseous muscle or suspensory ligament strains using in vivo data and an accurate subject-specific model. Kinematic data were recorded using invasive markers at the walk and trot. Computerized...
Murray RC, Dyson SJ, Tranquille C, Adams V.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 ...
Lawson SE, Chateau H, Pourcelot P, Denoix JM, Crevier-Denoix N.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...
Dyson SJ, Weekes JS, Murray RC.The aim of the study was to characterize radiopharmaceutical uptake patterns in horses with clinical and ultrasonographic evidence of proximal suspensory desmitis. It was hypothesized that radiopharmaceutical uptake in the proximal palmar (plantar) aspect of the third metacarpal (metatarsal) bone would be greater in lame limbs of horses with proximal suspensory desmitis than in sound limbs and that there would be a positive correlation between the severity of ultrasonographic abnormalities and the degree of radiopharmaceutical uptake. Nuclear scintigraphic evaluation of the proximal metacarpal...
Singer ER, Barnes J, Saxby F, Murray JK.Two related studies on injuries sustained by event horses during competition and during training are reported. During the cross-country phase of competition, the most common injuries were lacerations and abrasions to the carpus and stifle. Superficial digital flexor tendonitis and exertional rhabdomyolysis were significantly more common during Cours Complete Internationale (CCI) competitions compared to one-day event (ODE) competitions. The difference in injury types at ODEs and CCI competitions probably relates to the increased athletic demands of the CCI and the closer veterinary observation...
Bischofberger AS, Konar M, Ohlerth S, Geyer H, Lang J, Ueltschi G, Lischer CJ.The diagnosis of lameness caused by proximal metacarpal and metatarsal pain can be challenging. Magnetic resonance imaging (MRI) offers the possibility for further diagnosis but there have been no studies on the normal MRI appearance of the origin of the suspensory ligament (OSL) in conjunction with ultrasonography and histology. Objective: To describe the MRI appearance of the OSL in fore- and hindlimbs of sound horses and compare it to the ultrasonographic and histological appearance. The findings can be used as reference values to recognise pathology in the OSL. Methods: The OSL in the fore...
Lischer CJ, Ringer SK, Schnewlin M, Imboden I, Fürst A, Stöckli M, Auer J.The objective of the present clinical report was to investigate the short- and long-term outcomes of chronic proximal suspensory desmitis (PSD) treated with Extracorporeal Shockwave Treatment (ESWT). Fifty-two horses with chronic PSD in the forelimb (34 cases) or hindlimb (22 cases) were included in the study. Three horses had lesions in both hindlimbs and one in both forelimbs. The origin of the suspensory ligament was treated every three weeks for a total of three treatments using 2000 impulses applied by a focused ESWT device (Equitron) at an energy flux density of 0.15 mJ/ mm2. This treatm...
Schnabel LV, Bramlage LR, Mohammed HO, Embertson RM, Ruggles AJ, Hopper SA.Studies have shown that surgical removal of apical fracture fragments in Standardbred racehorses carries the best prognosis for return to racing performance, but there are no reports involving mature Thoroughbred (TB) racehorses. Objective: To describe the incidence of apical proximal sesamoid fractures in TB racehorses and determine probability and quality of racing performance after arthroscopic removal of such fractures in TB racehorses age > or = 2 years. Methods: Medical records and pre- and post operative race records of TB racehorses age > or = 2 years that underwent arthroscopic surger...
Hewes CA, White NA.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%)...
Halper J, Kim B, Khan A, Yoon JH, Mueller PO.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 ...
Smith JJ, Ross MW, Smith RK.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 ...
Bischofberger AS, Ringer SK, Geyer H, Imboden I, Ueltschi G, Lischer CJ.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,...
Lischer ChJ, Bischofberger AS, Fürst A, Lang J, Ueltschi G.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...
Minshall GJ, Wright IM.Clinical association between the branches of insertion of the suspensory ligament (SL) and metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints has been reported. However, there has been no assessment of the lengths of the SL branches which are subsynovial with respect to the joints or reports of involvement of the MCP/MTP joints in injuries of the SL branches. Objective: To establish proportions of SL branches subsynovial with respect to the MCP/MTP joints and report clinical and arthroscopic findings in horses with desmitis of SL branches identified as having an articular component...
Ringer SK, Lischer CJ, Ueltschi G.To monitor the effect of focused extra-corporeal shock wave therapy (ESWT) on bone and bone-tendon junction of horses without lameness by use of nuclear scintigraphy and thermography. Methods: 6 warmblood horses without lameness. Methods: The origin of the suspensory ligament at the metacarpus (OSL-MC) and the fourth metatarsal bone were treated at 2 time points (days 0 and 16) with 2,000 shocks applied by a focused ESWT device at an energy flux density of 0.15 mJ/mm2. One forelimb and 1 hind limb were treated, and the contralateral limbs served as controls. To document the effect of focused E...
Bardin AL, Taylor NC, Robert Colborne G.Thoroughbred racehorses are often affected by musculoskeletal injuries, leading to involuntary rest, early retirement or death. Hardness and consistency of the track surface have been implicated as major risk factors for limb injury. The purpose was to test the utility of a preliminary AnyBody musculoskeletal model of the equine forelimb for its responses on two perturbing surfaces. A musculoskeletal model was developed using CT, muscle, tendon and ligament properties, and kinematic data were applied from ridden trials using five Thoroughbred horses. Horses were ridden at trot and canter on a ...
Kadic DTN, Minshall GJ, Wright IM.Suspensory ligament branch injuries are common in horses. Most of these injuries are grouped together and considered as a single pathologic entity. Objective: To report a specific injury of the abaxial margin of the suspensory ligament branches and to report its surgical management and outcome. Methods: Retrospective case series. Methods: All horses with suspensory ligament branch injuries over a 9-year period (2007-2015) were identified. Horses with injuries which, on ultrasonographic examination, appeared to have defects in the abaxial margin of the suspensory ligament branch, that were subs...
Schade J, de Souza AF, Vincensi LC, Fonteque JH.The objective of this study was to assess the influence of the metacarpophalangeal (MCP) joint angle on the transversal area (TA) and mean echogenicity (ME) of the superficial digital flexor tendon (SDFT) and suspensory ligament (SL) in gaited horses. Ultrasound images were obtained from 50 healthy adult horses of the Mangalarga Marchador (MM; n=25) and Campeiro (n=25) breeds. Static and dynamic angles of the MCP joint were measured from photographs and video recordings. Higher ME values were evinced for the SL only in the group with the smaller dynamic angles of the MCP joint in the MM horses...
Hinkle FE, Selberg KT, Frisbie DD, Barrett MF.Comparison of radiography to magnetic resonance imaging (MRI) can help objectively assess the value and limitations of radiographs in orthopaedic disease processes. The tarsus and proximal suspensory origin of the metatarsus are commonly imaged regions for lameness. The knowledge gained by comparison between imaging modalities will aid in improving accuracy of radiographic interpretation. Objective: To compare the radiographic and MRI findings of the proximal third metatarsal bone (MTIII) and proximal suspensory ligament using MRI as the gold standard. Methods: Retrospective observational stud...
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 ...
Seabaugh KA, Selberg KT, Valdés-Martínez A, Rao S, Baxter GM.To investigate tissue diffusion of anesthetic agent following administration of low palmar nerve blocks (LPBs) in horses. Methods: Randomized clinical trial. Methods: 12 adult horses. Methods: In 9 horses, mepivacaine hydrochloride-iohexol (50:50 dilution) injections were administered bilaterally (2 or 4 mL/site) to affect the medial and lateral palmar and palmar metacarpal nerves (4 sites). Lateral radiographic views of both metacarpal regions were obtained before and at 5, 15, 30, 60, 90, and 120 minutes after block administration; proximal and distal extents of contrast medium (and presumab...
Nazem MN, Sajjadian SM.Palmar region of metacarpus in the horses and donkeys is an important region because of its tendons and ligaments which contribute to stay apparatus. This study was done on forelimbs of 6 healthy Miniature donkeys to detect the tendons, ligaments and their accessories on the palmar surface of metacarpus in this animal. Methods: Based on that magnetic resonance imaging (MRI) is a good technique to evaluate the soft tissues such as tendons and ligaments, palmar aspects of metacarpus in 6 euthanatised Miniature donkeys were prepared for anatomical and trans-sectional MRI studies to determine the ...
Walker VA, Walters JM, Griffith L, Murray RC.A recent epidemiological study indicated that various factors may be related to injury in dressage horses, but the mechanism by which these injuries occur has yet to be determined. The suspensory ligament (SL) is a frequent site of injury, and it is assumed that greatest strain is placed on this structure in collected trot; this has yet to be proved conclusively. The study aimed to investigate the effect of collected and extended trot on the hindlimb movement pattern. Four dressage horses were fitted with markers and inertial motion sensors (IMS). High-speed video was obtained for 2 strides on...
Elemmawy YM, Senna NA, Abu-Seida AM, Youssef AF.Injury of suspensory ligament (SL) branch is a frequently diagnosed problem in horses of different ages and disciplines. This case reports for the first time the ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) findings in a 10-year-old draught horse with traumatic chronic SL branch desmitis of 8 months duration. The horse had a grade 3 of 5 left hindlimb lameness with a moderately hot, painful, and diffuse swelling from the tarsus till the hoof. Ultrasonography, both SL branches appeared as enlarged hyperechogenic structures with poor demarcation of their margins a...
Milner PI, Dimmock O, Barnes K.Neurovascular variation may be relevant when performing surgical techniques to the proximal plantar metatarsal region. Objective: To document variations in the neurovascular anatomy of the proximal plantar metatarsal region and study the relationship of the neurovascular components to each other and other structures located in this area. Methods: Descriptive anatomical study. Methods: Paired cadaver hind limbs from 15 horses were dissected from the distal tibia to the metatarsophalangeal joint. Deep branch of the lateral plantar nerve (DBLPN) length, location of its origin from the lateral pla...
Imboden I, Waldern NM, Wiestner T, Lischer CJ, Ueltschi G, Weishaupt MA.Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects...
Tóth F, Schumacher J, Schramme M, Holder T, Adair HS, Donnell RL.To describe pathologic changes in the deep branch of the lateral plantar nerve (DBLPN) of horses determined to be lame because of proximal suspensory desmitis (PSD), and to report the outcome after treatment by excision of a segment of the horses' DBLPN. Methods: Retrospective case series. Methods: Adult horses (n=16). Methods: Horses determined to be lame on one or both pelvic limbs because of PSD were treated by excision of a segment of the DBLPN, and 30 nerves were examined histologically. Owners were contacted to obtain information about the horses >or=6 months after surgery. Results: H...
Zauscher JM, Estrada R, Edinger J, Lischer CJ.To evaluate intra- and interobserver variability in ultrasonographic measurements of the proximal aspect of the suspensory ligament (PSL) in the horse. Objective: A minimum difference of ≥20% is required to differentiate reliably between physiological and pathological alterations related to dimensions. Methods: Two operators examined the PSL in all 4 limbs of 14 horses twice using different techniques and different probes with and without standoff pads. Measurements were taken from the longitudinal and transverse images. Inter- and intraoperator variability was evaluated using agreement indi...
Le Jeune SS, Macdonald MH, Stover SM, Taylor KT, Gerdes M.Objective-To determine whether partial transection of the medial branch of the suspensory ligament (MBSL) alters equine third metacarpal bone (MC3) condylar surface strains and forelimb, distal joint angles in a manner consistent with promotion of lateral condylar fracture. Study Design-In vitro biomechanical experiment. Sample Population-Right forelimbs from 7 Thoroughbred horse cadavers. Methods-Lateral and medial MC3 condylar, dorsal and abaxial, bone surface strains and distal joint angles were measured both before and after partial transection of the MBSL during in vitro axial limb compre...
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...
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.
Williams J, Miyabayashi T, Ruggles A, Yamamoto J, Takiguchi M.A 2.5-year-old female Thoroughbred horse was referred to the veterinary teaching hospital for right front limb lameness of 1 year duration. Physical examination and diagnostic nerve blocks failed to localize the origin of the lameness. Scintigraphy with 99mTc-MDP suggested increased radionuclide uptake in the palmar metacarpal soft tissues of the right front limb. Ultrasonographic examination revealed hypoechoic lesions in the superficial digital flexor tendon and the suspensory ligament, suggesting tendinitis and desmitis. Combined imaging modalities improved detection and characterization of...
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...
Morrison S.Laminitis is a disease of the suspensory apparatus of the distal phalanx, which can advance to the chronic stage with varying degrees of structural failure. Because the disease may ultimately lead to mechanical failure of the digit, a foot management plan is required to effectively and mechanically treat these cases. Many laminitis cases can be successfully rehabilitated back to athletic soundness, light use, breeding, or pasture soundness, whereas others suffer from permanent instability and never enjoy an acceptable level of comfort. To understand how to minimize damage in the acute laminiti...
Mizobe F, Okada J, Shinzaki Y, Nomura M, Kato T, Yamada K, Spriet M.Desmitis of the oblique distal sesamoidean ligaments (ODSL) is caused by hyperextension of the metacarpophalangeal/metatarsophalangeal joint and has been described as a significant cause of lameness in racehorses. In this study, three Thoroughbred racehorses (age range: 3-6 years) were diagnosed with desmitis of the forelimb ODSL using standing low-field magnetic resonance imaging (sMRI). Radiography and ultrasonography were inconclusive with regard to a definitive diagnosis. For all horses, the sMRI characteristics included increased signal intensity within the medial ODSL on T1-weighted grad...
Samol MA, Uzal FA, Blanchard PC, Arthur RM, Stover SM.The most prevalent causes of death in racehorses are musculoskeletal injuries, causing ~83% of deaths within the racing industry in California and elsewhere. The vast majority of these injuries have preexisting lesions that predispose to fatal injury. A 4-y-old Thoroughbred colt suffered an acute suspensory apparatus failure, including biaxial proximal sesamoid bone fractures of the right front fetlock, causing loss of support of the fetlock joint and consequent fall with fractures of the cervical and sacral spine. Cervical fracture caused spinal cord damage that resulted in sudden death. A pr...
Noble P, Lejeune JP, Caudron I, Lejeune P, Collin B, Denoix JM, Serteyn D.Whereas the effect of heel configuration on the tension of the suspensory apparatus is well documented in the literature, there are few reports of joint contact force components in the equine distal forelimb. Objective: To improve understanding of the effect of heel configuration on equine digit joint loading, a sensitivity analysis was performed to compare the effect of a raised heel on joint contact force components in the coffin and fetlock joints during the stance phase of the trot. Methods: Four Warmblood horses were used. An inverse dynamic analysis was carried out using kinematic and ki...
Hill AE, Blea JA, Arthur RM, McIlwraith CW.Private-practice racetrack veterinarians in southern California recorded non-fatal injuries meeting defined criteria in Thoroughbreds for 1 year. Injury incidence was 2.29 injury events per 100 horse-months, which was lower than other studies where trainer reported injury data were collected. Of 477 injuries recorded, 344 (72.1%) were acute and 133 (27.9%) were chronic. Fractures were common (47.6% of injuries), with stress fractures accounting for 14% of injuries. Superficial digital flexor tendonitis and suspensory ligament desmitis accounted for 15.3 and 11.5% of injuries, respectively. Agr...
Takahashi T, Mukai K, Ohmura H, Aida H, Hiraga A.The purpose of this study was to create a lower forelimb model of the Thoroughbred horse for measuring the force in the superficial and deep digital flexor tendons (SDFT and DDFT), and the suspensory ligament (SL) during a trot. The mass, centers of gravity, and inertial moments in the metacarpus, pastern, and hoof segments were measured in 4 Thoroughbred horses. The moment arms of the SDFT, DDFT, and SL in the metacarpophalangeal (fetlock) and distal interphalangeal (coffin) joints were measured in 7 Thoroughbred horses. The relationship between the fetlock joint angle and the force in the SL...
Kamineni S, Ruggles A, Ashfaq H.Ultrasonic debridement as a treatment for tendinopathy and desmitis is a relatively new approach in orthopedic surgery. Previously only used in limited cases, this procedure shows promise for treating ligament-bone and tendon-bone interface injuries. We present a case study of a 2-yr-old thoroughbred male horse, unable to train due to recalcitrant symptoms after extensive conservative management of suspensory branch desmitis. It was then treated with ultrasonic debridement and concurrent manubrial stem cell autograft injection, to treat the ultrasound visualized lesion. Post-surgically, the pa...
Lavagnino M, Madison J, Williams MR, Arnoczky SP.To determine if regional variations in strain patterns occur within the suspensory ligament under tensile load. Local increases in strain may put certain regions of the suspensory ligament at risk and may explain the poor healing and high recurrence rates associated with suspensory branch injuries. Methods: The suspensory ligament and its bone attachments were isolated from each of 10 adult equine cadaveric forelimbs and radiodense reference beads were inserted throughout the length of the ligament. Specimens were attached to a custom fixture secured to a materials testing system. Radiographs ...
Mizobe F, Nomura M, Kato T, Nambo Y, Yamada K.Problems associated with the proximal metacarpal region, such as an osseous injury associated with tearing of Sharpey's fibers or an avulsion fracture of the origin of the suspensory ligament (OISL), are important causes of lameness in racehorses. In the present study, four Thoroughbred racehorses (age range, 2-4 years) were diagnosed as having forelimb OISL and assessed over time by using standing magnetic resonance imaging (sMRI). At the first sMRI examination, all horses had 3 characteristic findings, including low signal intensity within the trabecular bone of the third metacarpus on T1-we...
Keg PR, van den Belt AJ, Merkens HW, Barneveld A, Dik KJ.The influence of regional nerve blocks on lameness resulting from tendon injury was studied in six horses. Tendonitis was induced in the midmetacarpal region of the Superficial Digital Flexor Tendon (SDF), Deep Digital Flexor Tendon (DDF) and the Suspensory Ligament (SL) through collagenase injections. The results were evaluated through sequential clinical examinations, ultrasonographic imaging and kinetic gait analysis (force plate) during a period of 144 days post injury and subsequently compared with gross and microscopic findings. The lameness corresponding to the SDF and DDF tendon lesion...
de Souza AF, Pascual CJ, Maia BT, do Valle De Zoppa AL.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. ...
