Navicular bone fracture and severe deep digital flexor tendinopathy after palmar digital neurectomy in two horses.

Background: Navicular syndrome is a common cause of forelimb lameness in horses. Beyond changes to the navicular bone itself, horses with a clinical diagnosis of navicular syndrome often have pathology associated with other components of the navicular apparatus, including the navicular bursa, deep digital flexor (DDF) tendon, collateral sesamoidean ligaments, and impar ligament. Palmar digital neurectomy (PDN) is often used as a salvage procedure for horses diagnosed with navicular syndrome that become unresponsive to medical management. There are many potential complications associated with PDN, some of which are debilitating. Case Description: This report describes two cases of navicular bone fracture with severe DDF tendinopathy and distal interphalangeal joint subluxation/hyperextension that occurred 12 and 19 weeks after bilateral forelimb PDN. Conclusion: These two cases highlight the importance of proper patient selection before PDN due to the high incidence of undiagnosed soft tissue pathology in conjunction with radiographic evidence of navicular syndrome. Advanced imaging of the digit is recommended to identify and characterize any soft tissue pathology associated with the navicular apparatus before pursuing PDN to avoid disease progression and catastrophic injury.

Other Clinical Problems of the Equine Foot.

Many disorders affect the equine foot, and many hoof problems have multiple predisposing causes. Surgery may be necessary after conservative management has failed. Diseases of the hoof capsule may seem simple, but their effect on performance can be long-lasting and healing is often prolonged. Diagnosis of problems within the hoof capsule is enhanced with the use of computed tomography and MRI. The prognosis of fractures has improved with strategic placement of lag screws across fracture planes using aiming devices and advanced intraoperative imaging techniques. Collaboration between the clinician and a skilled farrier is important for successful management of hoof disorders.

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 pattern of sMRI signal change. Transcuneal ultrasonography did not allow assessment of morphology and extent of distal DDFT lesions, and sporadically discriminated the affected lobe compared to sMRI. Defects of the palmar compact bone were identified with both modalities except a parasagittal defect, which was only seen at sMRI.

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 for the DDFT were measured by histochemical stains. The amount of aligned and non-aligned collagen in tendons were calculated using Colour-Based Segmentation function. Regarding collagen, there were significant differences in the amount of aligned collagen (NA: 21.2 ± 1.31; NS-group: 12.2 ± 4.67; p = 0.0026) and non-aligned collagen (NA: 21.8 ± 2.22; NS: 25.1 ± 1.73; p = 0.0241) at the DDFT insertion in the distal phalanx. We concluded that the flexor tendons of the forelimb in equines with NS have different proportions of collagen than those that do not present the diagnosis, indicated by histologically visible increased proportions of non-aligned collagen and decreased of aligned collagen in the extracellular matrix.

Oral Supplementation with Ultramicronized Palmitoylethanolamide for Joint Disease and Lameness Management in Four Jumping Horses: A Case Report.

Background: Four show jumping horses were evaluated for non-responsive lameness, which caused their withdrawal from show jumping competitions. The clinical evaluation was performed by radiographic examination, flexion tests, diagnostic anesthesia and lameness evaluation using the American Association of Equine Practitioners (AAEP) scale. The diagnoses were a case of navicular syndrome, a complicated case of chronic navicular syndrome and arthrosis of the distal interphalangeal joint of the right anterior limb and two cases of distal intertarsal joint arthritis. Nutraceuticals are often an important management strategy or coadjutant of pharmacological therapies in joint disease. Ultramicronized Palmitoylethanolamide (PEA-um) is an endogenous fatty acid amide that is well-known for its anti-inflammatory and analgesic proprieties widely used in human medicine and small animal veterinary medicine. Although it includes a small number of cases, our study describes for the first time the efficacy of the use of PEA-um in horses. The four horses with non-responsive lameness and significant impairment in athletic performance were daily treated with PEA-um into their normal diet. After four months of PEA-um supplementation, all horses showed remissions of lameness that led to their reintroduction into showjumping competitions without disease recurrence. Therefore, despite the small number of cases included in this study, these observations suggest a good prospective for developing a controlled experiment to test PEA in a larger cohort of horses.

Painful type II os naviculare: introduction of a standardized, reproducible classification system.

OBJECTIVE: To provide a novel MRI classification system for the symptomatic type II os naviculare by creating a standardized grading of associated bone marrow edema (BME) and correlating with patient symptoms. METHODS: BME was classified on an ordinal scale: grade 1, faint signal immediately adjacent to the synchondrosis; grade 2, intermediate signal within the os and navicular tuberosity without extending to the navicular body; grade 3, intense signal extending to the navicular body. BME on 59 MRIs was independently graded by three radiologists. Inter- and intra-observer agreement was analyzed using intraclass correlation coefficient. Univariate and multivariate analyses assessed for patient and imaging characteristics predictive of subjective pain score. A cohort of 82 patients without BME represented a control group. RESULTS: Inter-observer agreement of BME grade was 0.95 (CI 0.93-0.97) and intra-observer was 0.92 (CI 0.87-0.96), indicating excellent agreement. In patients with BME, predictors of more severe pain were longer duration of pain (p = 0.02) and presence of soft tissue edema overlying the os naviculare (p < 0.001). One hundred percent of subjects with BME localized their pain to the medial midfoot (59/59) versus 25.6% (21/82) of controls (p < 0.001). CONCLUSIONS: This novel grading system provides reliable quantification of BME associated with os naviculare, which is a specific cause of medial foot/ankle pain. Early diagnosis is important as pain severity worsens with longer duration of symptoms. Pain severity is correlated with soft tissue edema overlying the os, which may be secondary to extrinsic compression, reactive to biomechanical stress, or reflect direct trauma.

What Do We Know About Clodronate Now? A Medical and Veterinary Perspective.

There has recently been some controversy over the use of bisphosphonates in horses and some confusion regarding the different classes of bisphosphonates and the differences between the mechanism of actions and effects of each class. This review article explores the different bisphosphonate classes and their different effects and mechanisms of action based on research from both the human and equine veterinary fields. This collaborative review between veterinary surgeons and medical doctors describes the latest use of bisphosphonates in humans and horses, including safety aspects, and allows comparisons to be drawn between the two fields. Potential future uses of bisphosphonates are also discussed.

Comparison of lameness outcomes in horses with acute or chronic digital lameness that underwent magnetic resonance imaging.

Aims: To compare the outcome, in terms of lameness score or return to athletic function, of horses with acute vs. chronic digital lameness that underwent magnetic resonance imaging (MRI) of the distal limb and to compare the proportion of horses that received intra-articular therapy of the distal interphalangeal (DIP) joint and pattern of diagnostic analgesia in these groups. Methods: This is a retrospective study of horses (n = 95) with acute (≤12 weeks; n = 46) or chronic (>12 weeks; n = 49) digital lameness that underwent MRI of the distal limb from 2009-2016, at two equine referral centres in the USA. Criteria for inclusion in the study were that a majority of lameness localised distal to the fetlock, and that lameness assessments for ≥12 months following MRI could be obtained from the medical record or the owner could be interviewed regarding their horse's athletic function. Outcome was characterised by an improvement score where 2 = return to work at a previous or higher level or lameness improved by one grade or more, 1 = return to work at a lower level or lameness improved by less than one grade, and 0 = did not return to work or lameness grade worsened. Whether horses had received intra-articular therapy of the DIP joint and the pattern of diagnostic analgesia prior to MRI was also obtained from medical records or by interviewing the owner. Results: There was a difference (p = 0.004) in the proportion of horses assigned to improvement scores of 0, 1 and 2 between horses with acute or chronic lameness. There was no evidence of a difference in the likelihood of having received intra-articular therapy of the DIP joint prior to MRI between horses with chronic or acute lameness (p = 0.085). Similarly, there was no evidence of a difference in the pattern of diagnostic analgesia prior to MRI between the two groups (p = 0.94). Eighty-two percent of owners of horses with acute and 62% of those with horses with chronic lameness had a positive opinion of the utility of MRI as a diagnostic modality. Conclusion: In a population of horses with digital lameness undergoing MRI, a difference in the outcome, in terms of lameness score or return to athletic function was identified between horses with acute lameness compared to those with chronic lameness. Clinical relevance: Horses with digital lameness that undergo MRI when the lameness is acute may have an improved prognosis due to accurate diagnosis and earlier application of appropriate therapy.

Bisphosphonate use in the horse: what is good and what is not?

BACKGROUND: Bisphosphonates (BPs) are a family of molecules characterized by two key properties: their ability to bind strongly to bone mineral and their inhibitory effects on mature osteoclasts and thus bone resorption. Chemically two groups of BPs are recognized, non-nitrogen-containing and nitrogen-containing BPs. Non-nitrogen-containing BPs incorporate into the energy pathways of the osteoclast, resulting in disrupted cellular energy metabolism leading to cytotoxic effects and osteoclast apoptosis. Nitrogen-containing BPs primarily inhibit cholesterol biosynthesis resulting in the disruption of intracellular signaling, and other cellular processes in the osteoclast. BODY: BPs also exert a wide range of physiologic activities beyond merely the inhibition of bone resorption. Indeed, the breadth of reported activities include inhibition of cancer cell metastases, proliferation and apoptosis in vitro. In addition, the inhibition of angiogenesis, matrix metalloproteinase activity, altered cytokine and growth factor expression, and reductions in pain have been reported. In humans, clinical BP use has transformed the treatment of both post-menopausal osteoporosis and metastatic breast and prostate cancer. However, BP use has also resulted in significant adverse events including acute-phase reactions, esophagitis, gastritis, and an association with very infrequent atypical femoral fractures (AFF) and osteonecrosis of the jaw (ONJ). CONCLUSION: Despite the well-characterized health benefits of BP use in humans, little is known regarding the effects of BPs in the horse. In the equine setting, only non-nitrogen-containing BPs are FDA-approved primarily for the treatment of navicular syndrome. The focus here is to discuss the current understanding of the strengths and weaknesses of BPs in equine veterinary medicine and highlight the future utility of these potentially highly beneficial drugs.

Ultrasonographic variations are present in the distal sesamoidean impar ligament of clinically sound horses.

Ultrasonography is an established diagnostic test for evaluating horses with foot pain due to suspected podotrochlear apparatus pathology. However, variations from the previously reported normal appearance of the distal sesamoidean impar ligament have not always coincided with lameness. The objective of this prospective, cross-sectional, descriptive study was to characterize variations in the ultrasonographic appearance of the distal sesamoidean impar ligament in sound horses using the transcuneal approach. Transcuneal ultrasonography of the distal sesamoidean impar ligament was performed on sound horses, and images were evaluated for fiber pattern, echogenicity, and thickness. Varying echogenicities of the distal sesamoidean impar ligament compared to the deep digital flexor tendon were found. Hypoechogenic or hyperechogenic focal areas were noted in the mid-body of the distal sesamoidean impar ligament or at its attachment to the navicular bone or the distal phalanx. In some of the sound horses, an anechoic linear area between the deep digital flexor tendon and distal sesamoidean impar ligament was observed as well as multifocal areas of hyperechogenicity or hypoechogenicity, irregular fiber pattern, and measurable thickening of the distal sesamoidean impar ligament. Several findings were bilaterally symmetrical, and no finding was always bilaterally symmetrical each time it was noted. This study supports transcuneal ultrasonography as an ancillary diagnostic tool for evaluating the equine distal sesamoidean impar ligament, describes sonographic variations in clinically sound horses, and suggests that the clinical significance of a lesion may not be determined by comparison of the distal sesamoidean impar ligament in the contralateral limb.

Accessory Navicular Syndrome in Athlete vs General Population.

BACKGROUND: Symptomatic accessory navicular syndrome (ANS) typically develops in young athletes. The symptoms are exacerbated during exercise or while walking, affecting the sports performance of athletes. The purpose of this study was to evaluate the radiologic findings and clinical course in athletes with accessory navicular syndrome (ANS) in comparison with a nonathletic population. METHODS: Seventy-nine patients with ANS between August 2012 and August 2013 were included. Overall, 29 were athletes and 50 were not athletes, and 19 (2 athletes and 17 nonathletes) of them improved after at least 6 months of conservative treatment. The records of 60 patients (64 consecutive feet) of ANS treated by modified Kidner operation were evaluated retrospectively. The study population included 27 athletes (31 feet) and 33 nonathletes (33 feet). Clinical features and radiologic findings were compared between them. RESULTS: Overall, 34% of the nonathletes improved after conservative treatment, but only 6.9% of athletes improved (P < .001). Mean age at surgery in the athlete group was 16.1 years (range, 12-26), and 24.3 years (range, 12-52) in the nonathlete group (P < .001). There was a history of trauma in 23 feet (74%) of the athlete group and in 13 feet (39%) of the nonathlete group (P = .006). Eighteen feet (58%) in the athlete group and 11 feet (32%) in the nonathlete group showed movement between the 2 bones (P = .047). Bone marrow edema was observed in both navicular and accessory navicular in all of the athletes (27/27, 100%). But it was only present in 80% (16/20) for nonathletes (P = .012). CONCLUSION: The radiologic findings and clinical course of athletes were different from that of the general population. Their symptoms were more refractory to conservative treatment than the nonathletes group. Therefore, early operative treatment could be considered in cases of symptomatic ANS especially for athletes. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Características planimétricas y estereológicas de los nervios palmar lateral y medial en manos de equinos con y sin síndrome navicular / Planimetric and stereological characteristics of lateral and medial palmar nerves in hands of equine with and without navicular syndrome

El Síndrome Navicular (SN) es una de las patologías claudicógenas mas frecuentes en la práctica clínica equina. Se ha descrito, cierta susceptibilidad individual respecto a ésta presentación clínica, es decir, algunos equinos con SN claudican y otros, con similares hallazgos radiográficos en mano no lo hacen sugiriendo que existen diferencias cuantitativas, entre equinos con y sin SN, en las características de las fibras nerviosas de los nervios periféricos que inervan la mano. El objetivo del estudio fue describir las características morfológicas cuantitativas de los nervios palmar lateral y medial en equinos con SN. Se obtuvo manos mediante un muestreo dirigido y diagnosticadas por inspección visual y evaluación radiográfica. Se conformó dos grupos: "No afectadas" (n= 6) y "Síndrome Navicular" (n= 8). Para determinar diferencias cuantitativos entre ambos grupos se realizó: i) Estudio 1, evaluó las características morfológicas, planimétricas y estereológicas de los nervios palmar lateral y medial, ii) Estudio 2: evaluó la cantidad de axones mielinizados y no mielinizados. En ambos estudios, el análisis de los datos morfológicos, estereológicos y planimétricos, en general, no detectó diferencias significativas entre grupos. En conclusión, los resultados obtenidos en el estudio no entregan evidencia morfológica respecto a diferencias entre nervios palmares entre equinos con y sin SN.

Navicular Syndrome (NS) is one of the most frequent claudicogen pathologies in the equine clinical practice. Certain individual susceptibility has been described in this clinical presentation, that is, some horses with SN halt, while others with similar radiographic findings in hand do not, suggesting that there are quantitative differences, between horses with and without clinical presentation of SN, on the characteristics of the nerve fibers of the peripheral nerves of the hand. The aim of this study was to describe the morphologic quantitative characteristics of the lateral and medial palmar in horses with SN nerves. Hands were obtained by sampling directed and diagnosed by visual inspection and radiographic evaluation. Two groups were formed: "Not affected" (n= 6) and "Navicular Syndrome" (n = 8). To determine quantitative differences between two groups we performed: i) Study 1: evaluated the morphological, planimetric and stereological lateral and medial palmar nerves, ii) Study 2: evaluated the number of unmyelinated and myelinated axons. In both studies, analysis of stereological, morphological and planimetric data generally detected no significant differences between groups. In conclusion, the results of the study do not provide morphological evidence for differences between palmar nerves between horses with and without SN.

Alterações radiográficas do aparato podotroclear de equinos da Polícia Militar de Minas Gerais sem sinais clínicos de doença do osso navicular / Radiographic changes in the podotroclear apparatus from Minas Gerais State Military horses without clinical signs of navicular disease

Os objetivos deste experimento foram identificar e associar alterações radiográficas do aparato podotoclear de equinos do Regimento de Cavalaria Alferes Tiradentes da Policia Militar do estado de Minas Gerais sem histórico e sinais clínicos de doença do osso navicular. Foi avaliado um total de 33 equinos, de ambos os sexos, com idade entre 10 e 20 anos. Os dígitos torácicos foram radiografados de forma padronizada nas projeções lateromedial (LM), dorsoproximal palmarodistal 65º (DPPD) e palmaroproximal palmarodistal (SK). A radiopacidade medular aumentada em projeção SK foi a principal alteração radiográfica detectada. Essa alteração foi associada a maior número de invaginações sinovais, a maior espessura de cortical em relação à medular em exposição SK e a maior relação corticomedular em exposição LM (P<0,05). Esses achados indicam uma predisposição da população equina para desenvolver a síndrome do osso navicular, possivelmente associada ao trauma repetitivo promovido pelo constante trabalho em piso duro.

The aims of this study were to identify and associate radiographic changes of podotoclear apparatus in horses from the Tiradentes Calvary Regiment of the Military Police of Minas Gerais State without history and clinical signs of navicular disease. 33 horses from both sexes, aged between 10 and 20 years were evaluated. The thoracic digits were radiographed in a standardized manner in lateralmedial (LM), palmaroproximal-distodorsal 65o(DPPD) and palmaroproximal-distopalmar (SK) projections. The increased medullary radiopacity in SK projection was the main radiological change detected and was associated with a higher number of synoval invaginations, increased cortical thickness in relation to medulla in SK exposure and increased corticomedullar in LM exposure (P < 0.05). These findings indicate a predisposition of this population to develop navicular syndrome, which is possibly associated with repetitive trauma promoted by constant work on hard floors.

Estudio histoquímico de la distribución de las fibras de colágeno en hueso sesamoídeo distal de equinos con y sin síndrome navicular / Histochemical study of the distribution of collagen fibers on distal sesamoid bone in equine with and without navicular syndrome

La significancia funcional de cualquier relación que exista entre la orientación de las fibras de colágeno y la tensión ejercida sobre una estructura ósea dependerá de la influencia de estos parámetros microestructurales sobre las propiedades biomecánicas del hueso y su capacidad de adaptarse. Se estudió la localización del colágeno en el hueso sesamoídeo distal (HSD) de la mano en equinos con Síndrome Navicular para observar cómo este refleja las demandas biomecánicas ejercidas por la tensión que ejerce el tendón del músculo flexor digital profundo sobre la articulación interfalángica distal. Se utilizaron las tinciones hematoxilina-eosina-azul alcián, y Rojo Picrosirius de Junqueira. La birrefringencia de colágeno óseo fue determinada utilizando microscopía de luz polarizada. La remodelación del HSD resultó en la formación de osteonas secundarias transversales orientados en una dirección lateral a medial y el colágeno óseo se orientó de manera similar. Estos resultados proporcionan evidencia de la existencia de una relación entre la función mecánica de un hueso con su arquitectura, incluso demuestra que esta se extiende hasta el nivel molecular.

The functional significance of any relationship exists between the orientation of the collagen fibers and the strain on a bone structure depend on the influence of these microstructural parameters on the biomechanical properties of bone and its ability to adapt. Localization of collagen was studied in the distal sesamoid bone (DSB) in in equine foot with Navicular Syndrome to see how this reflects the biomechanical demands by the tension exerted by the tendon of the deep digital flexor muscle on the joint distal interphalangeal. Hematoxylin-eosin-alcian blue staining, and Red Picrosirius of Junqueira were used. The birefringence of bone collagen was determined using polarized light microscopy. The remodeling of DSB resulted in the formation of transverse secondary osteons oriented lateral to medial and bone collagen was oriented in similar direction. These results provide evidence for the existence of a relationship between the mechanical function of a bone with the architecture, and shows further that this extends up to the molecular level.

Morfometría, planimetría y estereología en el hueso sesamoídeo distal en manos de equinos con y sin síndrome navicular / Morphometry, planimetry and stereology in the distal sesamoid bone in equine foot with and without navicular syndrome

El Síndrome Navicular (SN) es una patología claudicógena bilateral crónica, degenerativa y progresiva, que compromete alhueso sesamoídeo distal (HSD), labolsa podotroclear, ligamentosy a las superficies adyacentes al tendón del músculo flexor digitalprofundo en manos de equinos. La hipótesis de que las características morfológicas del HSD en la mano de equinos varían en aquellos que presentan SN fue evaluada en este estudio. Para determinar cambios morfológicos en el HSD en manos de equinos con SN se realizó un estudio morfométrico, planimétrico y estereológico. Fueron evaluados dos grupos: No Afectadas (n=11) y Síndrome Navicular (n=11). Se evaluaron variables tales como peso, volumen, mediciones lineales, área y parámetros estereológicos tales como densidad de número (NA), volumen (VV) y superficie (SV). Los resultados obtenidos indican que a pesar de existir un proceso patológico e inflamatorio en la región del HSD que induce cambios mesoscópicos y microscópicos atribuibles a SN, no lograrían modificar sus características macroscópicas.

Navicular Syndrome (NS) is a chronic, degenerative and progressive bilateral claudication pathology, compromising the distal sesamoid bone (DSB), the podotrochlear bursa, ligaments and adjacent surfaces of the tendon of the deep digital flexor muscle of equine foot. The hypothesis that morphological characteristics of HSB in hand of horses vary in those with SN was evaluated in this study. A study was carried out to determine the morphological changes in the DSB in 22 left foot of horses with NS. We realized morphometrical, planimetrical and stereological studies in two groups of horses feet: Not Affected (n=11) and Navicular Syndrome (n=11). The following variables were quantified: weight, volume, linear measurements, area and stereological parameters: densities of number (NA), volume (VV) and surface (SV). Results indicate that although there is a pathological and inflammatory process in the region of DSB which induces mesoscopic and microscopic changes attributable to SN, their gross morphological features were not modified.

Avaliação radiográfica e ultrassonográfica do aparato podotroclear de cavalos Quarto de Milha diagnosticados com síndrome do navicular / Radiographic and ultrasonographic evaluation of the podotrochlear apparatus in American Quarter horses diagnosed with navicular syndrome

O objetivo deste estudo foi avaliar as alterações do aparato podotroclear de 22 cavalos da raça Quarto de Milha acometidos pela síndrome do navicular utilizando o acesso transcuneal. Esses equinos foram submetidos ao exame radiográfico e ultrassonográfico. No exame radiográfico foi observado a presença de invaginação sinovial de diferentes tipos, além de calcificação da bursa podotroclear e tendão flexor digital profundo, entesiófitos, osteófitos e alteração do limite córtico-medular. No exame ultrassonográfico observou-se alterações da bursa podotroclear, aderência e irregularidades nos bordos do tendão flexor digital profundo, diminuição do coxim digital, calcificação do ligamento sesamóide distal ímpar e irregularidade da superfície flexora do osso sesamóide distal. Todos os equinos que apresentavam alterações radiográficas também apresentaram alterações no exame ultrassonográfico compatíveis com a síndrome do navicular. O exame ultrassonográfico utilizando o acesso transcuneal foi um método prático e eficiente para avaliação das lesões do aparato podotroclear dos eqüinos, sendo um método complementar ao exame radiográfico.

The objective of this study was to evaluate radiographically and ultrasonographically the podotrochlear apparatus using a transcuneal approach in 22 American Quarter horses suffering from navicular syndrome. On the radiographs, different forms of synovial invaginations, calcification of the podotrochlear bursa and deep digital flexor tendon, enthesophyte and osteophyte formation, and changes in the cortical-medullary margin were observed. On the ultrasound scans, changes of the podotrochlear bursa, adhesions and irregularities at the surface of the deep digital flexor tendon, the digital cushion area reduction, calcification of the impar distal sesamoideal ligament, and irregularities of the flexor surface of the distal sesamoid bone were observed. Radiographic and ultrasonographic abnormalities compatible with navicular syndrome were present in all patients. Ultrasonography using transcuneal approach was a practical and efficient method to evaluate podotrochlear apparatus injuries in equine, thus being a complementary method to radiography.