Computed tomography of the tarsal joint in clinically normal dogs

Usefulness of Imaging Techniques in the Diagnosis of Selected Injuries and Lesions of the Canine Tarsus. A Review

Simple Summary

Tarsal joint lesions are uncommon in dogs but may lead to serious health problems. The most common diseases involving the tarsal joint are osteochondrosis, fractures and injuries of the Achilles tendon. The basis for the diagnosis of lesions in the tarsus is a thorough orthopedic examination, sometimes performed under sedation. Imaging modalities such as radiography, ultrasonography, magnetic resonance imaging or computed tomography can facilitate the detection and assessment of lesions in the canine tarsal joint. The aim of this paper is to characterize and compare the usefulness of imaging techniques available in veterinary medicine for the diagnosis and evaluation of lesions and injuries affecting the tarsal joint in dogs.

Abstract

Tarsus lesions are not common in dogs, but they can cause serious health problem. They can lead to permanent changes in the joint and, in dogs involved in canine sports, to exclusion from training. The most common diseases and injuries involving the tarsal joint are osteochondrosis, fractures and ruptures of the Achilles tendon. These conditions can be diagnosed primarily through accurate orthopedic examination, but even this may be insufficient for performing a proper diagnosis. Imaging modalities such as radiography, ultrasonography, magnetic resonance imaging or computed tomography can facilitate the detection and assessment of lesions in the canine tarsal joint. This review paper briefly presents some characteristics of the above-mentioned imaging techniques, offering a comparison of their utility in the diagnosis of lesions and injuries involving the canine tarsus.

Description and outcome of prosthetic ligament placement for stabilization of medial or dorsomedial tarsometatarsal joint luxation in dogs and cats: 16 cases (2004-2017)

OBJECTIVE

To describe prosthetic ligament placement for reduction and stabilization of medial or dorsomedial tarsometatarsal joint luxation in dogs and cats and to report complications and postoperative outcomes for patients that underwent that procedure.

ANIMALS

14 dogs and 2 cats with medial or dorsomedial tarsometatarsal joint luxation.

PROCEDURES

The electronic database of a referral surgery practice was searched to identify records of dogs and cats with tarsometatarsal joint luxation that underwent prosthetic ligament placement between January 2004 and March 2017. For each study subject, information extracted from the medical record included signalment, a description of the tarsometatarsal joint injury, durations of anesthesia and surgery, and intraoperative and postoperative care and complications. Radiographic images were also reviewed. The long-term outcome for study subjects was assessed by administration of a standardized questionnaire to owners.

RESULTS

Prosthetic ligament placement successfully stabilized the luxated tarsometatarsal joint in all 16 patients. Six patients developed minor postoperative complications, which included bandage-associated dermatitis or ulceration (n = 5) and orthopedic wire failure (1). No major or catastrophic complications were reported. All 13 owners who completed the questionnaire perceived that the described technique resulted in satisfactory long-term function for their pets.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that prosthetic ligament placement was a technically simple procedure that achieved satisfactory long-term stabilization of the tarsometatarsal joint in small animal patients with medial or dorsomedial luxation of the joint. Prosthetic ligament placement may be an alternative to arthrodesis for tarsometatarsal joint stabilization in appropriate patients.

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.

Computed tomography and magnetic resonance imaging study of a normal tarsal joint in a Bengal tiger (Panthera tigris)

Background

In this research, using computed tomography (CT) and magnetic resonance imaging (MRI), we provide a thorough description of the standard appearance of a right tarsal joint in a Bengal tiger (Panthera tigris). CT scans were performed using a bone and soft tissue window setting, and three-dimensional surface reconstructed CT images were obtained. The MRI protocol was based on the use of Spin-echo (SE) T1-weighted and Gradient-echo (GE) STIR T2-weighted pulse sequences. Magnetic resonance (MR) images were taken in the transverse, sagittal and dorsal planes. We also performed anatomical dissections to facilitate the interpretation of the different structures of the tarsus joint and allow comparisons with CT and MRI images.

Results

The CT images allowed us to observe differences between the bones and soft tissues of the tarsal joint. When applying the bone window setting, the obtained footage showed the anatomy between the medulla and cortex. Additionally, the trabecular bone was delineated. By contrast, the soft tissue window allowed the main soft tissue structures of the tarsal joint, including ligaments, muscles and tendons, to be differentiated. Footage of the main anatomical structures of the standard tiger tarsus was obtained through MRI. The SE T1-weighted images showed the best evaluation of the cortical, subchondral and trabecular bone of the tibia, fibula, tarsus and metatarsus bones. Nonetheless, the GE STIR T2-weighted images allowed us to better visualize the articular cartilage and synovial fluid. In both MRI pulse sequences, the ligaments and tendons appeared with low signal intensity compared with muscles that were visible with intermediate signal intensity.

Conclusions

The results of this CT and MRI study of the Bengal tiger tarsal joint provide some valuable anatomical information and may be useful for diagnosing disorders in this large non-domestic cat.

Short and long-term outcome following surgical stabilization of tarsocrural instability in dogs

Objectives: To evaluate the outcome and complications following surgical stabilization of canine tarsocrural luxations.

Methods: Medical records of dogs which were surgically treated for tarsocrural joint instability between February 2007 and June 2014 were reviewed. Surgical technique, complications and long-term outcome (via questionnaire and Canine Brief Pain Inventory) were assessed.

Results: Twenty-four dogs (26 joints) were included. All injuries were traumatic. All joints had associated fractures; malleolar in 21/26 limbs (13/26 medial). Eight joints had internal fracture fixation and transarticular external skeletal fixator, six had external fixator alone, four had prosthetic ligaments with external fixator, and four had prosthetic ligaments with external coaptation. Two joints had pantarsal arthrodesis and two primary ligament repair. Complications occurred in 24/26 limbs giving 45 distinct complications; 16 were minor, 29 major, and 31 complications were external fixator associated. Prosthetic ligaments were significantly associated with major complications (p = 0.017); five out of eight required subsequent removal between 105–1006 days. Cost was significantly associated with major complications (p = 0.017) and soft tissue wounds (p = 0.03). Long-term lameness was seen in nine of 14 dogs. There was no association between pain severity (p = 0.3) and pain interference scores (p = 0.198) when comparing stabilization methods.

Clinical significance: Complications are common; however many are external fixator related. Prosthetic ligaments are significantly associated with major complications. Regardless of technique, a degree of ongoing lameness is likely.

Comparison of radiography and computed tomography to evaluate fractures of the canine tarsus

Detection and accurate classification of traumatic tarsal fractures are important for identifying cases requiring surgical intervention. The aim of this prospective, experimental, methods comparison study was to directly compare the accuracy, sensitivity, and specificity of tarsal computed tomography (CT), ten-view and two-view digital radiographs for detecting traumatic fractures of the canine tarsus. The working hypothesis was that tarsal fractures would be detected with higher accuracy, sensitivity, and specificity using CT imaging compared to radiography, and a ten-view would be superior to a two-view radiographic study. Ten cadaver hind limbs of medium to large dogs received a CT scan and ten-view radiographic study before and after induction of fractures with a hydraulic press. All bones included in the radiographic images were assessed for fractures by two observers and gross dissection was used as the gold standard. The two-view radiographic study (dorsoplantar, lateromedial) was created from the ten-view study and reviewed 2 years later. All limbs sustained fractures, the most common locations were the talus and calcaneus (n = 7). The sensitivity of CT was greater than ten-view radiographic study (77% vs. 57%), while the specificity was similar (97% vs. 98%). The sensitivity and specificity of the ten-view and two-view radiograph studies were similar (57% vs. 55%; both 98%). Computed tomography images were reassessed postdissection to determine if failure to identify fractures resulted from observer error. Overall, CT was better than radiography for detecting fractures of the canine tarsus, however there was little improvement with ten-view compared to two-view radiographic studies.

Computed tomography assisted determination of optimal insertion points and bone corridors for transverse implant placement in the feline tarsus and metatarsus

OBJECTIVE

Describe optimal corridors for mediolateral or lateromedial implant placement in the feline tarsus and base of the metatarsus.

METHODS

Computed tomographic images of 20 cadaveric tarsi were used to define optimal talocalcaneal, centroquartal, distal tarsal, and metatarsal corridors characterized by medial and lateral insertion points (IP), mean height, width, length and optimal dorsomedial-plantarolateral implantation angle (OIA).

RESULTS

Talocalcaneal level: The IP were at the head of the talus and plantar to the peroneal tubercle of the calcaneus and OIA was 22.7° ± 0.3. Centroquartal level: The IP were at the centre of the medial surface of the central tarsal bone and dorsoproximal to the tuberosity of the fourth tarsal bone and OIA was 5.9° ± 0.06. Distal tarsal level: The IP were at the centre of the medial surface of the tarsal bone II and dorsodistal to the tuberosity of the fourth tarsal bone and OIA was 5.4° ± 0.14. Metatarsal level: The IP were at the dorsomedial surface of the proximal end of the metatarsal bone II and at the dorsolateral surface of metatarsal bone V and OIA was 0.5° ± 0.06. Significant positive correlation was found between body weight and the length of each corridor.

CLINICAL SIGNIFICANCE

Most of the corridors obtained in this study had a diameter between 1.5 mm and 2 mm with a length of 15 mm to 18 mm, which stresses the importance of their accurate placement.

Canine tarsal architecture as revealed by high-resolution computed tomography

Central tarsal bone (CTB) fractures are well documented and are a subject of increasing importance in human, equine and canine athletes although the mechanism of these fractures in dogs is not fully understood and an extrapolation from human medicine may not be accurate. This study reports the use of high-resolution computed tomography (CT) of 91 tarsal joints from 47 dogs to generate a more detailed in situ anatomical description of the CTB architecture in order to obtain a better understanding of the pathogenesis of CTB fractures in this species. The dogs studied represented a wide range of ages, breeds and levels of habitual physical activity and the angles of the tarsal joints studied ranged between maximal flexion (16.4°) and maximal extension (159.1°). Regardless of tarsal angle, the CTB articulated with the calcaneus exclusively at the level of its plantar process (PPCTB) in all dogs. The PPCTB presented two distinct parts in all dogs, a head and a neck. The calcaneus tended to rely on the PPCTB neck during flexion and on the PPCTB head during extension. This study describes new tarsal elements for the first time, including the calcaneal articular process, the fourth tarsal bone plantar articular process and the talar plantar prominence of the CTB. Based on calcaneo-PPCTB architecture, it is postulated that the PPCTB is a keystone structure and that at least some of CTB fractures in dogs could either commence at or are induced at this level due to the impingement forces exercised by the calcaneus.

Observer variation in the evaluation and classification of severe central tarsal bone fractures in racing Greyhounds

OBJECTIVES

To determine observer agreement on radiographic evaluation of central tarsal bone (CTB) fractures and compare this with evaluation of the same fractures using computed tomography (CT).

METHODS

Radiographs and CT scans were obtained of the right tarsi from limbs of Greyhounds euthanatized after sustaining severe CTB fracture during racing. Four observers described and classified each fracture. Inter- and intra-observer agreements were calculated.

RESULTS

Inter-observer agreement was higher for assessment of fractures using CT. Several fractures assessed by radiography were misclassified as a less severe type. Intra-observer agreement for assessment and classification of CTB fractures via radiography versus CT was variable. Overall agreement among all four observers was higher for CT than radiography. Additionally, when identifying fractures of the adjacent tarsal bones, observer agreement was higher for CT than radiography.

CLINICAL SIGNIFICANCE

Computed tomography improved observer ability to correctly evaluate CTB fracture and detect the degree of displacement and extent of any comminution. Identification of fractures of adjacent tarsal bones was also improved when tarsi were assessed using CT. These data suggest that treatment decisions based solely on radiographic assessment of CTB fractures may not produce the expected outcome.

Normal cross-sectional anatomy of the bovine digit: comparison of computed tomography and limb anatomy

The purpose of this study was to define the structures of the digits and hoof in Holstein dairy cattle by using computed tomography scan (CT scan). Transverse, sagittal and dorsoplantar CT images of two isolated cattle cadaver digits were obtained using a Siemens ARTX2 Somatom. The CT images were compared to corresponding frozen cross-sections. Relevant anatomical structures were identified and labelled at each level. The CT images provided anatomical detail of the digits and hoof in Holstein dairy cattle. Transversal images provided excellent depiction of anatomical structures when compared to corresponding frozen cross-sections. The information presented in this paper would serve as an initial reference to the evaluation of CT images of the digits and hoof in Holstein dairy cattle.