High field magnetic resonance imaging anatomy of feline carpal ligaments is comparable to plastinated specimen anatomy

Feline carpal ligament injuries are often diagnosed indirectly using palpation and stress radiography to detect whether there is instability and widening of joint spaces. There are currently no reports describing normal feline carpal ligament anatomy and the magnetic resonance imaging (MRI) appearance of the carpal ligaments. The objective of this prospective, anatomic study was to describe normal feline carpal ligament anatomy using gross plastinated specimens and MRI. We hypothesized that MRI could be used to identify the carpal ligaments as previously described in the dog, and to identify species specific variations in the cat. The study was conducted using feline cadaver antebrachii that were radiographed prior to study inclusion. Three limbs were selected for MRI to confirm repeatability of anatomy between cats. The proton density weighted pulse sequence was used and images were acquired in transverse, dorsal, and sagittal planes. Following MRI, the limbs were plastinated and a collagen stain was used to aid in identification of carpal ligament anatomy. These limbs were sliced in sagittal section, and a further six paired limbs were included in the study and sliced in transverse and dorsal planes. Anatomic structures were initially described using MRI and then subjectively compared with gross plastinated specimens. Readers considered the transverse MRI plane to be most useful for visualizing the majority of the carpal ligaments. Findings indicated that MRI anatomy of the carpal ligaments was comparable to plastinated anatomy; therefore MRI appears to be a beneficial imaging modality for exploration of feline carpal pathology.     

Pericapsular hip desensitization in dogs: a cadaveric study and case series

ObjectiveTo develop and assess the efficacy of an ultrasound (US)-guided pericapsular hip desensitization (PHD) technique in dogs.Study designProspective, randomized, anatomical study and a case series.AnimalsA total of 30 healthy dogs, eight canine cadavers and seven dogs with hip osteoarthritis.MethodsAfter studying the US anatomy of the medial aspect of the coxofemoral joint and determining an acoustic window to perform an US-guided PHD in healthy dogs, the US-guided PHD was performed bilaterally in canine cadavers. A low [(LV) 0.1 mL kg^–1] and high [(HV) 0.2 mL kg^–1] volume of dye was injected per hip on each cadaver. The staining of the pericapsular nerves was assessed by anatomical dissection, and comparison between LV and HV was assessed using Fisher’s exact test. Then, the US-guided PHD was performed using a triamcinolone–bupivacaine solution in dogs with hip osteoarthritis. Dynamic pain response was assessed before and after injection. The canine brief pain inventory (CBPI) questionnaire was used to assess treatment efficacy and duration.ResultsThe US-guided PHD could be performed by inserting the needle between the iliopsoas muscle and the periosteum of the ilium. The articular branches of the femoral and obturator nerves were stained in all cadavers using both volumes. The main femoral nerve was never stained, but the main obturator nerve was stained in 37.5% and 100% of injections using LV and HV, respectively (p = 0.026). Treated animals showed decreased dynamic pain response after the injection. Compared with baseline, CBPI scores were reduced by ≥ 50% for ≥ 12 weeks in all but one dog.Conclusions and clinical significanceThe US-guided PHD with both 0.1 and 0.2 mL kg^–1 volumes stained the articular branches of the femoral and obturator nerves in canine cadavers and was associated with clinical improvement in dogs with hip osteoarthritis.     

Gross anatomy,computed tomography,magnetic resonance imaging and bone mineral densitometry of the ovine metacarpo/metatarsophalangeal joint

This study was aimed to provide anatomical atlas of the ovine metacarpo/metatarsophalangeal joints using computed tomography (CT) scan and magnetic resonance imaging (MRI), as well as to investigate bone mineral density (BMD) and morphometric features of this joint. The limbs of twenty adult Sanjabi sheep were examined. Imaging was performed using a 16-slice multi-detector CT scanner and a 1.5 Tesla MRI scanner. The obtained images were correlated with corresponding anatomical sections. BMD was measured by Dual Energy X-ray Absorptiometry (DEXA) method. Also morphometric features included distance between metacarpal and metatarsal heads, width of metacarpal and metatarsal head, length, width and the height of the proximal sesamoid bones were measured. In MRI images, compact bones, ligaments and tendons showed less signal intensity (hypointense). The fatty tissue and bone marrow had more signal intensity (hyperintense), but articular cartilage and synovial fluid showed moderate signal intensity. BMD in the left hind limb was significantly higher than other three limbs (p ≤ 0.05). The length of proximal sesamoid bones in left forelimb was higher than right forelimb (p ≤ 0.05). The thickness of proximal sesamoid bones in left limbs was higher than those in their counterparts (p ≤ 0.05). The width of the medial head in the forelimbs was significantly greater than the hind limbs (p ≤ 0.05). The present results might be useful in managing the clinical techniques on this joint. Larger volume of the proximal sesamoid bones and wider medial head in the forelimbs compared to the hindlimbs impel this speculation that the centre of gravity is closer to the forelimbs.     

Idiopathic infectious arthritis of the coxofemoral joint in a mature horse

The authors are aware of only one previously described case of idiopathic infectious arthritis of the coxofemoral joint in a mature horse. The case described herein presented with clinical signs that localised pain to the proximal limb, subtle increased radiopharmaceutical uptake at the coxofemoral joint and an increase of the major acute phase protein, serum amyloid A in the horse's blood biochemistry. The latter finding led the authors to search initially for an infective process. Ultrasound guided aspiration of the coxofemoral joint yielded infected synovial fluid. Despite the duration of the condition, nonsurgical treatment allowed the horse to return to its previous, relatively modest, level of activity. This case is presented to supplement the single previously published case report of idiopathic adult coxofemoral infectious arthritis in the horse.     

Total hip arthroplasty in the horse: Overview,technical considerations and case report

A total hip arthroplasty was performed in a small equine patient with a history of traumatic subluxation of the coxofemoral joint during infancy resulting in severe degenerative changes to the femoral head and acetabulum. The transtrochanteric surgical approach used to expose the joint, as well as the technique and technology to replace the joint, is described. The patient was weightbearing within 24 h of surgery and walking successfully without sling support 4 days post operatively. On the fifth post operative day, the patient abruptly deteriorated and succumbed to multiple pulmonary thromboemboli and a jejunal infarction. Despite the systemic complications in this case, the initial short‐term success of this treatment option indicate its potential to be considered in the management of equine coxofemoral joint disease/lesions.     

Open reduction and stabilisation of coxofemoral joint luxation in dogs and cats, using a stainless steel rope inserted via a ventral approach to the hip joint

Open reduction and stabilisation of coxofemoral joint luxation was made via a ventral approach to the hip joint in dogs and cats, using a transarticular stainless steel rope. A feature of the procedure is transarticular penetration of the rope from the pelvic cavity to the femoral neck by guidance with a guide wire which was previously inserted from the femoral neck into the pelvic cavity and by detection of the guide wire in the pelvic cavity by use of forceps connected to an alarm-ohmmeter. Forty-seven animals (37 dogs and 10 cats) with acute and simple coxofemoral luxation were treated and postoperatively maintained in cage rest without external fixation. Most of the animals regained an almost normal gait within several days.     

Treatment of coxofemoral luxation in a mature Welsh pony by femoral head ostectomy: Long‐term outcome

A 233 kg, 4‐year‐old Welsh pony stallion presented with a unilateral coxofemoral luxation and a history of previous upward fixation of the patella. This condition was surgically managed by femoral head ostectomy using a craniodorsal approach to the luxated coxofemoral joint, without greater trochanteric osteotomy. Immediate improvement in weightbearing was observed after surgery and primary intention healing was recorded. Long‐term outcome, 4 years after surgery, was assessed by radiographic, ultrasonographic and lameness examination. The pony was in good body condition and the initial weight of this patient was restored. Despite fetlock hyperlaxity of the contralateral hindlimb, amyotrophy and mechanical lameness of the affected hindlimb, the pony showed evident comfort without apparent signs of pain and was able to trot and gallop. Bone callus was observed at imaging examination.     

Ultrasonographic, computed tomographic and magnetic resonance imaging anatomy of the normal canine stifle joint

Ultrasonographic (US), magnetic resonance (MR) and computed tomographic (CT) images of normal canine stifle joints were obtained and compared with plastinated cross-sectional slices of cadaver specimens from the same dogs. The bony and articular structures were identified and correlated with the three diagnostic imaging modalities. These results provide an atlas of normal cross-sectional US, MR and CT anatomy of the canine stifle, which can be used for the interpretation of stifle images from any of these imaging modalities.     

Radiographic diagnosis of craniodorsal coxofemoral luxation in standing equids

Radiographic evaluation of the pelvis in standing horses has been used to diagnose fractures of the pelvis, head and greater trochanter of the femur, and luxations of the coxofemoral joint. Coxofemoral luxation injuries are more common in smaller horse breeds and donkeys, but, due to their size, the standing ventrodorsal projection is not possible, as there is insufficient space to place the radiography equipment under the animal's abdomen. The objective of the study was to report the advantages and limitations of the use of an oblique radiographic projection to diagnose unilateral craniodorsal coxofemoral luxation in 3 ponies and a donkey performed with the animals standing under light sedation. All cases had severe unilateral hindlimb lameness and asymmetry of the gluteal region; 2 also had concurrent intermittent upward fixation of the patella. A standing dorsolateral 20–30° ventral oblique radiograph of the affected coxofemoral joint was performed in all cases to obtain a definitive diagnosis. Radiography of the coxofemoral joint in standing ponies and donkeys can be carried out to identify craniodorsal coxofemoral luxation avoiding the need for general anaesthesia.     

Feline urticaria pigmentosa in three related Sphinx cats

Abstract A pruritic maculopapular eruption with clinical and histological features similar to urticaria pigmentosa of humans is reported in three related Sphinx cats. All cats shared the same grandsire, had a juvenile onset of disease, and demonstrated similar historical, clinical and histological findings. Physical examination revealed widespread bilaterally symmetrical, erythematous, partially coalescing, crusted macules and papules on the trunk, limbs, neck and head. A few macules exhibited a dark brown pigmentation. Dermatographism could not be elicited in any of the cats. Histological examination of papules revealed the présence of a perivascular to diffuse dermal and subcutaneous infiltrate of well-differentiated mast cells. In one cat where systemic involvement was pursued, evidence of internal disease was not found. Resumen Se describe en 3 gatos esfinge emparentados una erupción maculopapular pruritica con caracteristicas clinicas e histológicas similares a la urticaria pigmentosa en la especie humana. Todos los gatos compartian el mismo abuelo, desarrollaron la enfermedad en edad juvenil y mostraron hallazgos históricos, clinicos e histológicos similares. El examen fisico mostró pápulas y máculas costrosas, eritematosas, parcialmente unidas, generalizadas, bilaterales y simétricas localizadas en tronco, extremidades, cuello y cabeza. Algunas máculas mostraban una pigmentación marronácea oscura. No pudo provocarse dermatografismo en ninguno de los gatos. El examen histológico de las pápulas mostró la presencia de un infiltrado dérmico y subcutáneo perivascular a difuso compuesto por mastocitos bien diferenciados. No se encontró enfermedad sistémica en un animal en el que se evaluó esta posibilidad. [Vitale, C.B., Ihrke, P.J., Olivry, T., Stannard, A.A. Feline urticaria pigmentosa in three related Sphinx cats. (Urticaria pigmentosa felina en 3 gatos esfinge emparentados.) Veterinary Dermatology 1996; 7 : 227–233.] Résumé Les auteurs décrivent chez 3 chats Sphynx apparentés une eruption maculopapuleuse présentant des similitudes cliniques et histologiques avec l'urticaire pigmentaire humaine. Les 3 chats ont le même grandpère, présentent une apparition précoce des symptômes, et, une anamnèse, une clinique et une histologie similaires. L'examen clinique révèle des macules et des papules croûteuses à large distribution bilatérale et symétrique, érythèmateuses, partiellement coalescentes, sur le tronc, les membres, le cou et la tête. Quelques macules montrent une pigmentation brun foncé. La présence d'un dermographisme n'a pu être démontré chez aucun des chats. L'examen histologique des papules révèle la présence d'un infiltrat dermique et sous cutané périvasculaire à diffus de mastocytes bien différenciés. La recherche d'une atteinte systémique chez un des chats n'a pas montré d'atteinte interne. [Vitale, C.B., Ihrke, P.J., Olivry, T., Stannard, A.A. Feline urticaria pigmentosa in three related Sphinx cats. (Urticaire pigmentaire féline chez 3 chats Sphynx apparentés.) Veterinary Dermatology 1996; 7 : 227–233.] Zusammenfassung Es wird über eine juckende makulopapuläre Eruption mit klinischen und histologischen Befunden, die der Urticaria pigmentosa des Menschen ähneln, bei drei verwandten Sphinx-Katzen berichtet. Alle Katzen hatten den selben Großvater, zeigten einen Krankheitsbeginn im Jugendalter und wiesen ähnliche Befunde in der Vorgeschichte, Klinik und Histologie auf. Die klinische Untersuchung zeigte weit verteilte, bilateral symmetrische, erythematöse, teilweise koaleszierende verkrustete Maculae und Papeln am Rumpf, Gliedmaßen, Hais und Kopf. Einige maculae wiesen eine dunkelbraune Pigmentierung auf. Dermatographismus konnte bei keiner der Katzen ausgelöst werden. Die histologische Untersuchung der Papeln zeigte die Anwesenheit eines perivaskulären bis diffusen dermalen und subkutanen Infiltrates von gut differenzierten Mastzellen. Bei einer Katze mit systemischen Erscheinungen konnte die Ursache der inneren Erkrankung nicht gefunden werden. [Vitale, C.B., Ihrke, P.J., Olivry, T., Stannard, A.A. Feline urticaria pigmentosa in three related Sphinx cats (Feline Urticaria pigmentosa bei drei verwandten Sphinx-Katzen). Veterinary Dermatology 1996; 7 : 227–233.]     

Feline atopy in three littermates

This case report describes the history, clinical signs and diagnosis of a pruritic skin disease in three sibling cats living the same household. Clinical signs consistent with pruritus (i.e. hair pulling, hair loss, excessive grooming and face rubbing) were first noted when the cats were 6 months of age. The cats were treated for a possible ear mite and/or flea infestation; there was no response to treatment and clinical signs progressed. Although the presence of pruritus in a multiple cat household suggested an infectious or contagious aetiology, none could be identified. There was no improvement in clinical signs after a 60‐day flea control trial, three treatments of ivermectin, an 8‐week restricted diet or removal from the home for 10 days. A diagnosis of feline atopy was made on the basis of elimination of other causes of pruritus, consistent history and clinical signs, a positive intradermal skin test and response to therapy.     

Coxofemoral arthroscopy and total hip arthroplasty for management of intermediate grade fibrosarcoma in a dog

OBJECTIVE: To report the use of arthroscopy and total hip arthroplasty (THA) for management of intermediate grade fibrosarcoma of the femoral head in a dog. STUDY DESIGN: Clinical case report. ANIMAL: A 6-year-old spayed female Rottweiler presented for evaluation of acute-onset of lameness of the right pelvic limb of approximately 10 days duration. METHODS: Coxofemoral arthroscopy was performed to obtain fine needle aspiration and Jamshidi biopsy of a lytic lesion of the femoral head. A cemented THA was performed removing as much of the femoral neck and proximal femur as possible while not compromising implant or joint stability. RESULTS: Histologic evaluation of specimens from the femoral head and neck remnants confirmed an intermediate grade fibrosarcoma. Fifteen months after THA, subjectively there was normal use of the right limb with only limited decrease in range of motion and mild muscular atrophy. Radiographs demonstrated stationary positioning of the THA implants. CONCLUSIONS: Arthroscopy of the coxofemoral joint is an effective diagnostic tool for evaluation of disease of the articular structures and canine total hip replacement may be an appropriate means of limb salvage in rare cases of disease of the femoral head. CLINICAL RELEVANCE: This case provides support for the use of coxofemoral arthroscopy as a diagnostic tool as well as an aid in acquiring representative intraarticular tissue samples. Additionally, the case presented demonstrates the potential use of THA as a limb sparing technique in cases of disease affecting the femoral head of dogs.     

Reliability of high‐ and low‐field magnetic resonance imaging systems for detection of cartilage and bone lesions in the equine cadaver fetlock

Reasons for performing study: To determine the reliability of 2 magnetic resonance imaging (MRI) systems for detection of cartilage and bone lesions of the equine fetlock. Objectives: To test the hypotheses that lesions in cartilage, subchondral and trabecular bone of the equine fetlock verified using histopathology can be detected on high‐ and low‐field MR images with a low incidence of false positive or negative results; that low‐field images are less reliable than high‐field images for detection of cartilage lesions; and that combining results of interpretation from different pulse sequences increases detection of cartilage lesions. Methods: High‐ and low‐field MRI was performed on 19 limbs from horses identified with fetlock lameness prior to euthanasia. Grading systems were used to score cartilage, subchondral and trabecular bone on MR images and histopathology. Sensitivity and specificity were calculated for images. Results: High‐field T2*‐weighted gradient echo (T2*W‐GRE) and low‐field T2‐weighted fast spin echo (T2W‐FSE) images had high sensitivity but low specificity for detection of cartilage lesions. All pulse sequences had high sensitivity and low–moderate specificity for detection of subchondral bone lesions and moderate sensitivity and moderate–high specificity for detection of trabecular bone lesions (histopathology as gold standard). For detection of lesions of trabecular bone low‐field T2*W‐GRE images had higher sensitivity and specificity than T2W‐FSE images. Conclusions: There is high likelihood of false positive results using high‐ or low‐field MRI for detection of cartilage lesions and moderate–high likelihood of false positive results for detection of subchondral bone lesions compared with histopathology. Combining results of interpretation from different pulse sequences did not increase detection of cartilage lesions. MRI interpretation of trabecular bone was more reliable than cartilage or subchondral bone in both MR systems. Potential relevance: Independent interpretation of a variety of pulse sequences may maximise detection of cartilage and bone lesions in the fetlock. Clinicians should be aware of potential false positive and negative results.     

Computed tomographic anatomy of the temporomandibular joint in the young horse

Reasons for performing study: The equine temporomandibular joint (TMJ) and its surrounding structures can be difficult to investigate in cases with a clinical problem related to the region. Little previous attention has been given either to a computed tomographic (CT) imaging protocol for the joint or an interpretation of the structures displayed in CT images of the normal joint. Objectives: To provide a CT atlas of the normal cross‐sectional anatomy of the equine TMJ using frozen and plastinated sections as anatomical reference. Methods: Eight TMJs from 4 immature pure‐bred Spanish horses were examined by helical CT. Scans were processed with a detailed algorithm to enhance bony and soft tissue. Transverse CT images were reformatted into sagittal and dorsal planes. Transverse, sagittal and dorsal cryosections were then obtained, photographed and plastinated. Relevant anatomic structures were identified in the CT images and corresponding anatomical sections. Results: In the CT images, a bone window provided excellent bone detail, however, the soft tissue components of the TMJ were not as well visualised using a soft tissue window. The articular cartilage was observed as a hyperattenuating stripe over the low attenuated subchondral bone and good delineation was obtained between cortex and medulla. The tympanic and petrous part of the temporal bone (middle and inner ear) and the temporohyoid joint were seen in close proximity to the TMJ. Conclusions: Helical CT provided excellent images of the TMJ bone components to characterise the CT anatomy of the normal joint. Potential relevance: Detailed information is provided that may be used as a reference by equine veterinarians for the CT investigation of the equine TMJ and serve to assist them in the diagnosis of disorders of the TMJ and related structures (middle and inner ear). The study was performed at an immature stage and further studies of mature individuals are required in order to confirm that the clinical interpretation is not affected by changes occurring with age.     

A comparison of 3-T magnetic resonance imaging and computed tomography arthrography to identify structural cartilage defects of the fetlock joint in the horse

Articular cartilage defects are prevalent in metacarpo/metatarsophalangeal (MCP/MTP) joints of horses. The aim of this study was to determine and compare the sensitivity and specificity of 3-Tesla magnetic resonance imaging (3-T MRI) and computed tomography arthrography (CTA) to identify structural cartilage defects in the equine MCP/MTP joint. Forty distal cadaver limbs were imaged by CTA (after injection of contrast medium) and by 3-T MRI using specific sequences, namely, dual-echo in the steady-state (DESS), and sampling perfection with application-optimised contrast using different flip-angle evolutions (SPACE). Gross anatomy was used as the gold standard to evaluate sensitivity and specificity of both imaging techniques.CTA sensitivity and specificity were 0.82 and 0.96, respectively, and were significantly higher than those of MRI (0.41 and 0.93, respectively) in detecting overall cartilage defects (no defect vs. defect). The intra and inter-rater agreements were 0.96 and 0.92, respectively, and 0.82 and 0.88, respectively, for CT and MRI. The positive predictive value for MRI was low (0.57). CTA was considered a valuable tool for assessing cartilage defects in the MCP/MTP joint due to its short acquisition time, its specificity and sensitivity, and it was also more accurate than MRI. However, MRI permits assessment of soft tissues and subchondral bone and is a useful technique for joint evaluation, although clinicians should be aware of the limitations of this diagnostic technique, including reduced accuracy.     

Normal anatomic reference of pastern and coffin joints in Egyptian buffalo (Bubalus bubalis): A compared atlas of cross-sectional anatomy,magnetic resonance imaging and computed tomography

The purpose of this study was to describe normal magnetic resonance imaging and computed tomographic anatomy of pastern and coffin joints in Egyptian buffalo using cadaveric distal limbs. This study was achieved using twelve fresh cadaveric distal limbs from adult healthy buffaloes of both sexes. These cadaveric limbs were scanned using a 1 Tesla MRI scanner and CT scanner, injected with red latex, frozen at −20°C for 1 week, and then sectioned into sagittal, dorsal and transverse slices. The obtained MR and CT images were selected to be matched with their corresponding anatomical cross-sections for identification and evaluation of the clinically correlated anatomical structures of the pastern and coffin joints. The difference in signal intensities on CT and MRI scans amongst the tissues allowed clear differentiation of major bone and soft tissue structures of the pastern and coffin joints. CT provided a high spatial resolution of bone and soft tissue structures, however, MRI allowed a better and higher resolution and definition between soft tissues. The current study provided a normal CT and MRI anatomic reference which could help veterinary clinicians for interpretation and diagnosis of the clinically affected pastern and coffin joints in buffalo.     

Characteristics of magnetic resonance images of granulomatous meningoencephalomyelitis in 11 dogs

The characteristics of magnetic resonance imaging (mri) of the brains and spinal cords of 11 dogs with histologically confirmed granulomatous meningoencephalomyelitis (gme) were determined. The lesions were in the brain of eight of the dogs, in the brain and spinal cord of two, and in the spinal cord alone in one dog. A single lesion was present in four of the dogs and multiple lesions were found in six. In one dog with intracranial signs, no visible lesions could be detected on mri. No meningeal enhancement was detected in T1-weighted images post-contrast, or in fluid attenuation inversion recovery (flair) images, but there were histological lesions in the meninges in nine of the dogs. The T2-weighted images and flair sequences were characterised in all cases by hyperintensity, whereas the signal intensity of the lesions on T1-weighted images was variable. After the administration of paramagnetic contrast, some of the lesions showed no enhancement, but others showed marked patterns of enhancement. The lesions in 10 of the dogs were easily identifiable by mri and the images had several unifying characteristics, but they could not be considered disease-specific.