The navicular bone is a small, boat-shaped bone located in the hoof of a horse, specifically situated behind the coffin bone and beneath the deep digital flexor tendon. It plays a role in the biomechanics of the equine foot by acting as a fulcrum for the deep digital flexor tendon, aiding in the horse's movement and weight distribution. The navicular bone is part of the navicular apparatus, which includes surrounding ligaments and the bursa, a fluid-filled sac that reduces friction. Issues with the navicular bone and associated structures can lead to a condition known as navicular syndrome, which is characterized by lameness and pain in the front feet. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, function, and pathophysiology of the navicular bone, as well as diagnostic and treatment options for navicular-related conditions in horses.
Olive J, Vila T, Serraud N.To compare navicular bone marrow lesion (BML) conspicuity in the feet of horses as determined via 2 fat-suppressed MRI techniques, including standard short tau inversion recovery (STIR) and inversion recovery gradient echo (IRGE). Methods: Feet (n = 150) of horses with lameness referable to the distal portion of the digit. Methods: STIR and IRGE sequences were obtained prospectively in all feet with a standing low-field equine MRI system. Presence of a BML was ascertained by identification of a characteristic combination of marrow alterations in T1-weighted, T2*-weighted, T2-weighted, and STIR...
Biggi M, Dyson S.The distribution of lesions detected using magnetic resonance imaging (MRI) of hind feet has not been reported. Objective: To evaluate type and distribution of lesions detected using MRI in hind feet of lame horses and to compare the findings with those reported in front feet; to document follow-up information. Methods: Horses were selected if hindlimb lameness was abolished by plantar nerve blocks performed at the base of the proximal sesamoid bones. Magnetic resonance images were acquired using either a low-field or a high-field magnet, and all images were evaluated retrospectively by both a...
Marsh CA, Schneider RK, Sampson SN, Roberts GD.To determine treatment outcome on the basis of pathological changes identified on MRI and lameness duration in horses with navicular syndrome that underwent injection of corticosteroid and hyaluronan into the navicular bursa. Methods: Retrospective case series. Methods: 101 horses with navicular syndrome. Methods: Medical records of horses with signs of navicular syndrome evaluated between January 2000 and December 2008 were reviewed. Data on signalment, use of the horse, history, affected limbs, duration of lameness, findings on lameness examination, radiographic findings, MRI findings, treat...
Holroyd K, Dixon JJ, Mair T, Bolas N, Bolt DM, David F, Weller R.Foot conformation in the horse is commonly thought to be associated with lameness but scientific evidence is scarce although it has been shown in biomechanical studies that foot conformation does influence the forces acting on the deep digital flexor tendon (DDFT) and the navicular bone (NB). The aim of this study was to determine the relationships between foot conformation and different types of lesion within the foot in lame horses. It was hypothesised that certain conformation parameters differ significantly between different types of foot lesions. Conformation parameters were measured on m...
Holowinski ME, Solano M, Maranda L, García-López JM.Adhesions occur in the navicular bursa between the deep digital flexor tendon (DDFT) and other structures. Our objectives were to describe the appearance of navicular bursa adhesions on high-field magnetic resonance (MR) images, to compare these findings to findings at navicular bursoscopy, and to determine the prevalence of lesions in the remainder of the podotrochlear apparatus. Sixteen forelimbs from 14 horses that underwent MR imaging and navicular bursoscopy were evaluated. Adhesions were considered type 1 when characterized by a discontinuity in the navicular bursa fluid signal between t...
Dyson S, Blunden T, Murray R.There is limited knowledge about both histological features in early navicular disease and what histological features are represented by increased signal intensity in fat-suppressed magnetic resonance (MR) images of the navicular bone. Objective: To characterise increased signal intensity in the spongiosa of the navicular bone in fat-suppressed MR images and to compare this with histopathology; and to compare objective grading of all aspects of the navicular bone on MR images with histological findings. Methods: One or both front feet of 22 horses with foot pain and a median lameness duration ...
Gutierrez-Nibeyro S, Werpy N, White Ii N.Conventional imaging modalities can diagnose the source of foot pain in most cases, but have limitations in some horses, which can be overcome by using magnetic resonance imaging (MRI). However, there are no reports of the MRI appearance and prevalence of foot lesions of a large series of horses with chronic foot lameness. Methods: In the present study, 79 horses with unilateral or bilateral forelimb lameness because of chronic foot pain underwent standing low-field MRI to make a definitive diagnosis. Results: Of the 79 horses, 74 (94%) had alterations in >1 structure in the lame or lamest foo...
Claerhoudt S, Bergman HJ, Van Der Veen H, Duchateau L, Raes EV, Saunders JH.Distal border synovial invaginations of the distal sesamoid bone are radiographically assessed during the selection process of horses admitted as breeding stallions or in purchase examinations. Nowadays, many moderately or some deeply penetrating proximally enlarged synovial invaginations are considered as moderate or severe radiographic findings. Objective: To measure the difference between and agreement of the morphology of distal border synovial invaginations on radiography vs. computed tomography (CT). It was hypothesised that the morphology of distal border synovial invaginations would be...
Waguespack RW, Hanson RR.Navicular syndrome is a chronic, progressive condition affecting the navicular bone and bursa, deep digital flexor tendon (DDFT), and associated soft tissue structures composing the navicular apparatus. The treatment options for navicular syndrome are as varied as the proposed causes of the condition. The severity of clinical signs, intended use and workload of the horse, and owner compliance with therapy are important considerations in developing a treatment plan. Nonsurgical treatment of navicular syndrome consists of rest, hoof balance and corrective trimming/shoeing, and medical therapy, i...
Smith MR, Wright IM.Diagnostic navicular bursoscopy has been described in limited cases. Review of greater numbers is needed to define its contribution to case management and prognostic values. Objective: To report: 1) clinical, diagnostic and endoscopic findings in a series of cases, 2) surgical techniques and case outcomes and 3) prognostic values. The authors hypothesise: 1) lameness localising to the navicular bursa is commonly associated with dorsal border deep digital flexor tendon (DDFT) lesions, 2) endoscopy allows extent of injuries to be assessed and treated, 3) case outcome relates to severity of DDFT ...
Biggi M, Dyson S.The significance of distal border fragments of the navicular bone is not well understood. There are also no objective data about changes in thickness and proximal/distal extension of the palmar cortex of the navicular bone. Objective: To describe the distribution of distal border fragments and their association with other radiological abnormalities of the navicular bone and describe the shape of the navicular bone in sound horses and horses with foot-related lameness, including navicular pathology. Methods: Sound horses had radiographs acquired as part of a prepurchase examination. Lame horses...
Vallance SA, Bell RJ, Spriet M, Kass PH, Puchalski SM.To date, few reports exist comparing magnetic resonance imaging (MRI) and computed tomography (CT) for imaging of the equine distal limb, yet clinicians are required to decide which modality to use regularly. Objective: To report and compare anatomic visualisation scores obtained for CT, contrast enhanced CT (CECT) and standing low-field MRI (LFMRI) in the equine foot. Objective: Anatomic visualisation score discrepancies would exist between CT, CECT and LFMRI. Methods: Images of 22 lame horses (31 limbs) undergoing both CT and LFMRI of the foot were reviewed. When available, CECT images were ...
Maher MC, Werpy NM, Goodrich LR, McIlwraith CW.Magnetic resonance (MR) imaging is often performed to determine the cause of palmar heel pain. We evaluated how distension of the navicular bursa affected the MR appearance of the navicular bursa and associated structures. An MR evaluation was performed on normal cadaver limbs and cadaver limbs from horses with lameness localized to the foot. The normal navicular bursae were injected with 2, 4, or 6 ml of solution. The bursae of the feet from lame horses were injected with 4 or 6 ml, and the MR study was repeated. All bursae were examined grossly to verify the presence or absence of adhesions....
Biggi M, Dyson S.Distal border fragments of the navicular bone can be seen in lame and nonlame horses and their clinical significance remains open to debate. Objective: To describe the magnetic resonance imaging (MRI) appearance of distal border fragments and the adjacent navicular bone. To investigate the relationship between fragments and other abnormalities of the navicular bone and the distal sesamoidean impar ligament (DSIL). Methods: Horses were included if pain causing forelimb lameness was localised to the foot and high-field MR images were acquired. The size and location of distal border fragments wer...
Rabba S, Bolen G, Verwilghen D, Salciccia A, Busoni V.Foot pain is an important cause of lameness in horses. When horses with foot pain have no detectable radiographic abnormalities, soft-tissue assessment remains a diagnostic challenge without magnetic resonance (MR) imaging. Ultrasonography can provide an alternative to MR imaging when that modality is not available but the extent of changes that might be seen has not been characterized. We reviewed the ultrasonographic findings in 39 horses with lameness responding positively to anesthesia of the palmar digital nerves and without radiographically detectable osseous abnormalities. Thirty of the...
Claerhoudt S, Pille F, Vanderperren K, Hauspie S, Duchateau L, Van der Vekens E, Saunders JH.To investigate whether in navicular bones (NB) from warmbloods, distal border fragmentation is associated with the shape of the proximal articular border or other radiological findings. Methods: Radiographs of the front feet of 325 normal, subadult horses presented for admission as breeding stallions were reviewed. Results: The proximal articular border of the total of 650 NB was classified as straight (n = 278), convex (n = 184), undulating (n = 147) or concave (n = 41). Distal border fragments were present in 57 NB (8.8%). They were significantly more prevalent in NB with a concave (9/41; 22...
Jenner F, Kirker-Head C.To determine the physiologic response of the equine navicular bone to core decompression surgery in healthy horses. Methods: Experimental in vivo study. Methods: Healthy adult horses (n=6). Methods: Core decompression was completed by creating three 2.5-mm-diameter drill channels into the navicular bone under arthroscopic control. The venous (P(V)), arterial (P(A)), articular (P(DIPJ)), and intraosseous pressures (IOP) were recorded before and after decompression drilling. Each IOP measurement consisted of a baseline (IOP(B)) and a stress test (intramedullary injection of saline solution, IOP(...
Jenner F, Kirker-Head C.To determine the effect of core decompression surgery and bone mineral density (BMD) on the mechanical properties of equine navicular bones. Methods: Experimental, in vitro study. Methods: Fore limb navicular bones (n=36 pairs) from sound 2-5-year-old horses with no radiographic abnormalities of the distal aspect of the forelimbs. Methods: Navicular BMD was measured using dual energy X-ray absorptiometry. One randomly assigned navicular bone from each pair served as control. The contralateral test specimen was allocated to 1 of 6 treatment groups defined by drill bit size (3.2 versus 2.5 mm di...
Waguespack R, Hanson RR.Navicular syndrome is a chronic and often progressive disease affecting the navicular bone and bursa, deep digital flexor tendon (DDFT), and associated soft tissue structures composing the navicular apparatus. This syndrome has long been considered one of the most common causes of forelimb lameness in horses. Diagnosis of navicular syndrome is based on history, physical examination, lameness examination, and peripheral and/or intraarticular diagnostic anesthesia. Several imaging techniques (e.g., radiography, ultrasonography, nuclear scintigraphy, thermography, computed tomography [CT], magnet...
Lopes MS, Diesterbeck U, Machado Ada C, Distl O.Navicular disease is characterized by a progressive degenerative alteration of the equine podotrochlea. In this study, we refined a previously identified quantitative trait locus (QTL) on horse chromosome 10 for the abnormal development of canales sesamoidales (DCS) of the navicular bone in Hanoverian warmblood horses. Genotyping was done in 192 Hanoverian warmblood horses from 17 paternal half-sib groups. The whole marker set comprised 45 markers including seven newly developed microsatellites and 13 single nucleotide polymorphisms (SNPs) within positional candidate genes. Chromosome-wide sig...
Biggi M, Dyson S.There are no data concerning the accuracy of conventional and computed or digital radiography for evaluation of the equine foot. Objective: To compare conventional film-screen and computed radiography with magnetic resonance imaging (MRI) for detection of distal border fragments of the navicular bone; and to establish which type of fragment was more likely to be detected radiologically. Methods: Horses were included if forelimb lameness was localised to the foot and both radiography and high-field MR images had been acquired. Horses were divided into 2 groups based on acquisition of convention...
Fowlie JG, O'Neill HD, Bladon BM, O'Meara B, Prange T, Caron JP.The conventional arthroscopic approach to the palmar/plantar aspect of the distal interphalangeal joint (DIPJ) may result in the inadvertent penetration of the digital flexor tendon sheath (DFTS) and the navicular bursa (NB). This iatrogenic communication would be undesirable subsequent to arthroscopic lavage of a septic DIPJ. Objective: A lateral/medial approach to the palmar/plantar aspect of the DIPJ will result in a significantly lower rate of inadvertent penetration of the DFTS and NB, whilst still providing adequate intra-articular evaluation. Methods: The conventional palmar/plantar app...
Gutierrez-Nibeyro SD, White Ii NA, Werpy NM.Currently, there are limited data regarding the long-term outcome of horses with foot pain treated with corrective shoeing, rest and rehabilitation, and intrasynovial anti-inflammatory medication to target lesions detected with MRI. Objective: To report the long-term (≥12 months) outcome of horses with foot lesions following medical therapy. Objective: 1) There is no association between clinical parameters considered and a poor response to therapy. 2) Horses with a deep digital flexor tendinopathy are less likely to respond to medical therapy than horses without a deep digital flexor tendino...
Dyson S, Pool R, Blunden T, Murray R.There is limited knowledge about the interpretation of alterations in the distal sesamoidean impar ligament (DSIL) detected using magnetic resonance imaging (MRI) and their correlation with histopathology. Objective: There would be: 1) a correlation between histopathology and MRI findings; and 2) a relationship between MR abnormalities at the origin and the insertion of the DSIL, between insertion and body; and origin and body. Methods: Fifty limbs from 28 horses were examined using high-field MRI and histopathology. MR abnormalities of the DSIL, its origin on the navicular bone and its insert...
Scandella M, Lazzaretti SS, De Zani D, Cassano M, Zani DD, Ravasio G, Gualtieri M.Tenoscopy of the navicular bursa has been recently introduced as a diagnostic and therapeutic treatment in cases of palmar foot pain syndrome. A deep digital flexor tendon transthecal approach was suggested in 1999, and the endoscopic technique has been reviewed. Smith and coworkers have recently reported good and promising results. An anatomic cadaver limb study was performed, and the endoscopic technique was evaluated. Subsequently, a 14-year-old Argentine mare, affected by palmar foot pain syndrome, was treated. Clinical data, MRI and endoscopic findings, and a 6-month follow-up evaluation ...
Haupt JL, Caron JP.To compare the proportion of the proximal recess of the navicular bursa that could be examined through a single endoscopic portal and the severity of iatrogenic lesions between conventional and modified approaches. Methods: Descriptive study. Methods: Equine cadaver forelimbs (n=16). Methods: Arthroscopic access to the navicular bursa in 1 limb of each pair was by a conventional approach and in the other limb, by a modified approach using sharp dissection through the distal digital flexor sheath, immediately palmar to the T ligament. The time required to access the bursa and the estimated prop...
Boyce M, Malone ED, Anderson LB, Park S, Godden SM, Jenner F, Trumble TN.To determine whether triamcinolone acetonide diffuses from the distal interphalangeal joint (DIPJ) to the navicular bursa, diffusion is direct or systemic, and addition of sodium hyaluronan has an effect on diffusion in horses. Methods: 11 adult horses without forelimb lameness. Methods: 1 randomly chosen forelimb DIPJ of each horse received an injection of 10 mg of triamcinolone acetonide plus 20 mg of sodium hyaluronan (group 1), and the contralateral forelimb DIPJ received an injection of 10 mg of triamcinolone acetonide plus 2 mL of lactated Ringer's solution (group 2). Synovial fluid samp...
Schramme M, Kerekes Z, Hunter S, Nagy K, Pease A.Fibrocartilage degeneration is the earliest pathologic finding in navicular disease but remains difficult to detect, even with magnetic resonance (MR) imaging. We hypothesized that injection of the navicular bursa with saline would improve accuracy of MR imaging evaluation of palmar fibrocartilage. Thoracic limbs were collected from 11 horses within 6 h of death. Imaging was performed with a 1.5 T magnet using sagittal 2D proton density and transverse 3D FLASH sequences with fat saturation. For the purpose of determining sensitivity and specificity of the MR images, fibrocartilage was classifi...
Sampson SN, Schneider RK, Gavin PR, Ho CP, Tucker RL, Charles EM.Seventy-two horses with recent onset of navicular syndrome and normal radiographs were assessed. Horses underwent magnetic resonance (MR) imaging of both front feet. All abnormalities were characterized and the most severe abnormality identified, if possible. Abnormal signal intensity in the navicular bone was the most severe abnormality in 24 (33%) horses. Pathologic change in the deep digital flexor tendon was the most severe abnormality in 13 (18%) horses. Pathologic change in the collateral sesamoidean ligament was the most severe abnormality in 11 (15%) horses. Pathologic change in the di...
Weaver MP, Shaw DJ, Munaiwa G, Fitzpatrick DP, Bellenger CR.The objectives of this study were to topographically map pressure distribution across the palmar surface of the navicular bone in response to forces applied by the deep digital flexor tendon (DDFT), and evaluate the effect of raising the heels in vitro . A rig was constructed to hold an equine cadaver limb and apply controlled pressure to the navicular bone from the DDFT. Pressure-sensitive paper was used to quantify and map the resultant pressure. Changes in response to heel wedges (5 degrees and 10 degrees ) were recorded. The areas subject to maximum pressure from the DDFT were: the central...
Marsh CA, Schneider RK, Sampson SN, Roberts GD.To determine treatment outcome on the basis of pathological changes identified on MRI and lameness duration in horses with navicular syndrome that underwent injection of corticosteroid and hyaluronan into the navicular bursa. Methods: Retrospective case series. Methods: 101 horses with navicular syndrome. Methods: Medical records of horses with signs of navicular syndrome evaluated between January 2000 and December 2008 were reviewed. Data on signalment, use of the horse, history, affected limbs, duration of lameness, findings on lameness examination, radiographic findings, MRI findings, treat...
Bowker RM, Van Wulfen KK, Springer SE, Linder KE.To examine macro- and microscopic characteristics of cartilage of the distal phalanx (ungual cartilage [UC]) and digital cushion in the equine foot and to relate them to the foot's function of energy dissipation. Methods: 85 horses and 5 foals of various breeds and ages. Methods: Feet, obtained at necropsy, were perfused with India ink (n = 30), latex (5), or polymer plastic (10). Select feet were examined histologically for tissue architecture and to identify elastic fibers. Immunochemistry to identify substance P peptides in nerves (feet from foals) and gold chloride impregnation of axons (n...
Widmer WR, Buckwalter KA, Fessler JF, Hill MA, VanSickle DC, Ivancevich S.Radiographic evaluation of navicular syndrome is problematic because of its inconsistent correlation with clinical signs. Scintigraphy often yields false positive and false negative results and diagnostic ultrasound is of limited value. Therefore, we assessed the use of computed tomography and magnetic resonance imaging in a horse with clinical and radiographic signs of navicular syndrome. Cadaver specimens were examined with spiral computed tomographic and high-field magnetic resonance scanners and images were correlated with pathologic findings. Radiographic changes consisted of bony remodel...
Svalastoga E, Smith M.The subchondral bone pressure in the navicular bone of horses with navicular disease is compared with corresponding pressures in normal horses. An increased intraosseous pressure and a lengthened pressure drop time was demonstrated in patients with navicular disease, which indicates the existence of a venous stasis. Compared with similar investigations in humans with arthrosis it is concluded that navicular disease is a condition resembling arthrosis. The classical clinical symptoms are explained as an expression of resting pains. Treatments are suggested which theoretically can render the pat...
Dyson SJ.It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. Th...
Johnson SA, Barrett MF, Frisbie DD.Radiographic flexor cortical lysis indicates advanced degenerative change and its earlier recognition may improve case outcome. Aims of this prospective, diagnostic accuracy study were to determine effects of radiographic beam angle and observer on accuracy of lesion detection. The sample included 36 limbs from 31 horses. Palmaroproximal-palmarodistal oblique (skyline) radiographs were acquired at standard (n = 38) and more shallow (alternate) angles (n = 58). Images were independently reviewed by four experience levels of five observers each (n = 20) for the presence and severity of fle...
Dyson SJ, Kidd L.Analgesia of the distal interphalangeal (DIP) joint and of the navicular bursa was performed independently in the lame or lamer forelimb of 59 horses, in which lameness was significantly improved by perineural analgesia of either the palmar digital or palmar (abaxial sesamoid) nerves. In 3 horses no improvement was detected. Lameness was improved by analgesia of the DIP joint but there was no response to analgesia of the navicular bursa in 3 horses. In 12 horses, lameness was improved by analgesia of the navicular bursa but intra-articular analgesia resulted in no change. Forty-one horses resp...
Rijkenhuizen AB.The 21st century has heralded a reassessment of our ideas about
navicular disease. In particular, the proposal of different
pathological entities has led to alternative treatment regimes and a
sounder basis for reaching a prognosis. Further, recently generated
data have given grounds for reconsidering both terminology and
treatment. The impact of recent information on the clinical
approach to suspected navicular disease of concepts relating to
diagnostic analgesia, the evolution of diagnostic imaging
techniques, biomarkers, biomechanics and heritability require
placing into the contex...
Németh F, Dik KJ.A sagittal fracture of the navicular bone in five horses was treated by means of lag screw. Intra-operative radiographic monitoring and a specially developed guide apparatus was necessary to implant the screw precisely along the transverse axis of the navicular bone. Internal fixation resulted in progressive radiographic narrowing of the fracture zone. In all five patients the fracture healed (bony union) without superfluous callus formation.
Ostblom LC, Lund C, Melsen F.Although the diagnostic criteria of navicular disease are generally accepted in practice, their limitations are recognised. However, the authors believe that navicular disease per se is reversible and that only secondary changes like adhesions to the deep flexor tendon or spur formations are irreversible. This hypothesis is supported by the results presented of the effect of the application of an egg-bar shoe, which caused permanent cessation of signs of navicular disease in more than 50 per cent of treated cases. The egg-bar shoeing technique can be usefully applied in practice.
Claerhoudt S, Bergman HJ, Van Der Veen H, Duchateau L, Raes EV, Saunders JH.Distal border synovial invaginations of the distal sesamoid bone are radiographically assessed during the selection process of horses admitted as breeding stallions or in purchase examinations. Nowadays, many moderately or some deeply penetrating proximally enlarged synovial invaginations are considered as moderate or severe radiographic findings. Objective: To measure the difference between and agreement of the morphology of distal border synovial invaginations on radiography vs. computed tomography (CT). It was hypothesised that the morphology of distal border synovial invaginations would be...
Leach DH.The future directions of navicular disease research are unclear. Often researchers investigate only one of the multitude of factors likely to be important in understanding the disease. Two exceptions to this is work done by Wright in this issue of EVJ and by MacGregor (1988) who compared a number of the treatment regimens (e.g. rest, warfarin, isoxsuprine, shoeing with egg bars) and found that approximately 75% of the horses improved in their performance. Perhaps this percentage of 'recovered' horses from this disease is what can be realistically expected, as often horses with navicular diseas...
Symonds KD, MacAllister CG, Erkert RS, Payton ME.To evaluate the musculoskeletal analgesic effect of etodolac administered PO every 12 or 24 hours in chronically lame horses by use of force plate analysis. Methods: 22 horses with navicular syndrome. Methods: Horses received etodolac (23 mg/kg, PO, q 12 h; n = 7), etodolac (23 mg/kg, PO, q 24 h; 8), or corn syrup (20 mL, PO, q 24 h; control treatment; 7) for 3 days. Combined forelimb peak vertical ground reaction force (PVF) was measured via force plate analysis before the first treatment (baseline) and at 6, 12, 24, and 36 hours after the last treatment. Differences in mean PVF (mPVF) betwee...
Schumacher J, Schumacher J, Gillette R, DeGraves F, Schramme M, Smith R, Perkins J, Coker M.Analgesia of the palmar digital (PD) nerves has been demonstrated to cause analgesia of the distal interphalangeal (DIP) joint as well as the sole. Because the PD nerves lie in close proximity to the navicular bursa, we suspected that that analgesia of the navicular bursa would anaesthetise the PD nerves, which would result in analgesia of the DIP joint. Objective: To determine the response of horses with pain in the DIP joint to instillation of local anaesthetic solution into the navicular bursa. Methods: Lameness was induced in 6 horses by creating painful synovitis in the DIP joint of one f...
Vacek JR, Welch RD, Honnas CM.An arthroscopic approach to the palmaroproximal or plantaroproximal pouch of the distal interphalangeal joint was developed in six cadaver limbs and seven limbs of three clinically normal horses. The dorsal aspect of the proximal border and the proximal articular margin of the distal sesamoid (navicular) bone, the palmar aspect of the distal articular margin of the middle phalanx, the collateral sesamoidean ligaments of the distal sesamoid bone, and the joint capsule attachments were readily accessible. Distending the joints with fluid gave access to portions of the articular surface between t...
Harper J, Schumacher J, Degraves F, Schramme M, Schumacher J.Specific analgesic techniques are required in diagnosis of lameness to isolate the exact origin of pain to the many structures of the foot that may be involved. Objective: To determine if analgesia of the digital flexor tendon sheath (DFTS) results in anaesthesia of other portions of the foot, such as the sole, distal interphalangeal joint (DIPJ), or navicular bursa (NB). Methods: Lameness caused by pain in the dorsal margin or heel region of the sole of the foot was induced in 18 horses by: using set-screws to create solar pressure (Trial 1: n = 5); or administering endotoxin intrasynovially ...
Martin GS, McIlwraith CW, Turner AS, Nixon AJ, Stashak TS.A retrospective study was made of 21 horses in which proximal interphalangeal arthrodesis had been performed. The right hindlimb was the most often affected (52%). Acute trauma was the most common reason for performing the surgery (62%). Follow-up data were obtained from the owners regarding return to serviceability . When available, follow-up radiographs and clinical examinations were reviewed. Of the 20 horses on which follow-up information was available, 16 were serviceable . Of the horses in which a hindlimb was arthrodesed , 86% were serviceable , whereas 67% of the horses affected in the...
Wright IM, Phillips TJ, Walmsley JP.A technique for evaluation of the navicular bursa using a 4 mm 25 degrees inclined view arthroscope is described. This allows examination of the palmar/plantar surface of the navicular bone, the insertions of the navicular suspensory, T and impar ligaments, the bursal synovium and the dorsal surface of the deep digital flexor tendon. The technique was used in 16 horses with punctures of the navicular bursa. Procedures facilitated by the technique were bursal lavage, removal of pannus, synovial resection and debridement of lesions on the palmar/plantar surface of the bone and in the deep digita...
Perez-Jimenez EE, Biedrzycki AH, Morton AJ, McCarrel TM.To determine the influence of a custom 3D-printed guide for placement of cortical bone screws in the equine navicular bone. Methods: Ex vivo study. Methods: Eight pairs of normal adult equine forelimbs. Methods: A 3.5 × 55 mm cortical screw was placed in the longitudinal axis of each intact navicular bone. Screws were placed with a 3D-printed guide (3D) in one bone and with a traditional aiming device (AD) in the contralateral bone within each pair. Duration of surgery and the number of fluoroscopy images were compared between techniques. Screw placement was subjectively evaluated by gros...
Belacic ZA, Sullivan SN, Rice HC, Durgam SS.To investigate the effects of interleukin-1β (IL-1β) and methylprednisolone acetate (MPA) on equine intrabursal deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) cells in vitro. Methods: Third passage DDFT and NBF cells from 5 healthy donor horses ages 11-17 years euthanized for reasons unrelated to musculoskeletal conditions. Methods: Aggregate cultures were incubated with culture medium alone (control), 10 ng/mL IL-1β, 10 ng/mL IL-1β + 0.05 mg/mL MPA, or 10 ng/mL IL-1β + 0.5 mg/mL MPA for 24 hours. Extracellular matrix (ECM) gene expressions were assessed via rea...
Reeves MJ, Yovich JV, Turner AS.The etiology, clinical presentation, radiographic findings, diagnostic criteria, differential diagnoses, treatment, and prognosis are reviewed for several clinically important conditions of the equine foot. These include pedal osteitis, sheared heels, distal sesamoid bone (navicular) fractures, subchondral bone cyst of the distal phalanx, distal interphalangeal joint subluxation, congenital phalangeal hypoplasia, bipartite and tripartite distal sesamoid bones, keratoma, ossification of the cartilages of the distal phalanx (sidebones), necrosis of the cartilages of the distal phalanx (quittor),...
Schramme MC, Boswell JC, Hamhougias K, Toulson K, Viitanen M.Numerous different techniques for injection of the navicular bursa have been described but there is little conformity between these descriptions. A literature review was performed and techniques for injection of the navicular bursa were categorised into 5 approaches. This study was performed to evaluate the reproducibility of each technique and to assess which technique was consistently most successful. Five inexperienced operators performed each technique on 5 cadaver forelimbs. Once a needle had been placed, a radiograph was taken to confirm placement was in accordance with the description o...
Pauwels FE, Schumacher J, Castro FA, Holder TE, Carroll RC, Sega GA, Rogers CW.To determine whether clinically effective concentrations of methylprednisolone or triamcinolone can be achieved in the navicular bursa after injection of methylprednisolone acetate (MPA) or triamcinolone acetonide (TA) into the distal interphalangeal joint (DIPJ) and whether clinically effective concentrations of these drugs can be achieved in the DIPJ after injecting the navicular bursa with the same doses of MPA or TA. Methods: 32 healthy horses. Methods: Horses in groups 1 through 4 received 40 mg of MPA in the DIPJ, 10 mg of TA in the DIPJ, 40 mg of MPA in the navicular bursa, and 10 mg of...
McGill SL, Gutierrez-Nibeyro SD, Schaeffer DJ, Hartman SK, O'Brien RT, Joslyn SK.Abnormalities of the deep digital flexor tendon, navicular bone, and collateral sesamoidean ligament can be difficult to visualize using magnetic resonance imaging (MRI) if bursal fluid is absent. The use of saline podotrochlear bursography improves podotrochlear apparatus evaluation, however, the technique has disadvantages. The objective of this prospective feasibility study was to describe saline arthrography of the distal interphalangeal joint as an alternative technique for improving MRI visualization of the deep digital flexor tendon, navicular bone, collateral sesamoidean ligament, and ...
Smith DR, Leach DH, Bell RJ.Anatomical anomalies in the hind feet of a seven month old Appaloosa foal were identified and investigated through the use of gross anatomical dissection, radiography and angiography. Abnormalities were restricted to the distal aspect of both hind legs, the right hind leg being more severely affected. Anatomically the right foot resembled that of an equine fetus of approximately 120 days gestational age. Disruption of vascular perfusion to hoof structures was evident in both hind legs and was related to areas of abnormal bone conformation as well as to areas of abnormal ossification and calcif...
Rabba S, Bolen G, Verwilghen D, Salciccia A, Busoni V.Foot pain is an important cause of lameness in horses. When horses with foot pain have no detectable radiographic abnormalities, soft-tissue assessment remains a diagnostic challenge without magnetic resonance (MR) imaging. Ultrasonography can provide an alternative to MR imaging when that modality is not available but the extent of changes that might be seen has not been characterized. We reviewed the ultrasonographic findings in 39 horses with lameness responding positively to anesthesia of the palmar digital nerves and without radiographically detectable osseous abnormalities. Thirty of the...
Maher MC, Werpy NM, Goodrich LR, McIlwraith CW.Magnetic resonance (MR) imaging is often performed to determine the cause of palmar heel pain. We evaluated how distension of the navicular bursa affected the MR appearance of the navicular bursa and associated structures. An MR evaluation was performed on normal cadaver limbs and cadaver limbs from horses with lameness localized to the foot. The normal navicular bursae were injected with 2, 4, or 6 ml of solution. The bursae of the feet from lame horses were injected with 4 or 6 ml, and the MR study was repeated. All bursae were examined grossly to verify the presence or absence of adhesions....
Fowlie JG, O'Neill HD, Bladon BM, O'Meara B, Prange T, Caron JP.The conventional arthroscopic approach to the palmar/plantar aspect of the distal interphalangeal joint (DIPJ) may result in the inadvertent penetration of the digital flexor tendon sheath (DFTS) and the navicular bursa (NB). This iatrogenic communication would be undesirable subsequent to arthroscopic lavage of a septic DIPJ. Objective: A lateral/medial approach to the palmar/plantar aspect of the DIPJ will result in a significantly lower rate of inadvertent penetration of the DFTS and NB, whilst still providing adequate intra-articular evaluation. Methods: The conventional palmar/plantar app...
Smith MR, Wright IM.Diagnostic navicular bursoscopy has been described in limited cases. Review of greater numbers is needed to define its contribution to case management and prognostic values. Objective: To report: 1) clinical, diagnostic and endoscopic findings in a series of cases, 2) surgical techniques and case outcomes and 3) prognostic values. The authors hypothesise: 1) lameness localising to the navicular bursa is commonly associated with dorsal border deep digital flexor tendon (DDFT) lesions, 2) endoscopy allows extent of injuries to be assessed and treated, 3) case outcome relates to severity of DDFT ...
Turner TA, Fessler JF, Lamp M, Pearce JA, Geddes LA.The distal forelimbs of 10 clinically normal horses with hair clipped on 1 limb were thermographically scanned before and after exercise. The thermal patterns, temperature distribution, and temperature changes after exercise were determined and compared with those of 8 horses with podotrochlosis. Clipping the hair did not cause changes in the thermal patterns, but the clipped limbs were warmer than the unclipped limbs. The temperature of the limbs of horses with podotrochlosis did not increase as much after exercise as did the limbs of normal horses. The failure of skin temperature increase co...
