Joints Of Dogs Research Articles

Low-Field Magnetic Resonance Imaging for the Detection of Medial Meniscal Lesions in Cranial Cruciate-Deficient Stifle Joints in Dogs.

The aim of this study was to substantiate the ability of noninvasive low-field magnetic resonance imaging (lfMRI) to accurately depict meniscal lesions, thereby establishing lfMRI as a viable option for the diagnosis of meniscal pathology. This was a prospective, controlled study. In each of 57 stifle joints, 5 predefined lfMRI sequences using a 0.25 T lfMRI were used. The scans were evaluated by an experienced surgeon (DECVS) and through external assessment by a radiologist (DECVDI). The patients were divided into two groups depending on their meniscal status after lfMRI. Dogs (Group 1; n = 33) without lfMRI evidence of medial meniscal pathology underwent TPLO, whereas concurrent craniomedial mini-arthrotomy was performed in patients with suspected meniscal lesions (Group 2; n = 24). Gait assessment was performed 6 weeks later and 6 months postoperatively. Cohen's kappa value of 0.8571 corresponds to a high level of agreement between the observers. A significant correlation was found between preoperative lameness severity and intraoperative meniscal damage (p < 0.04). The results showed a highly significant correlation between meniscal injuries on MRI and intraoperative findings (p < 0.0001). LfMRI appears to be a noninvasive, reliable imaging tool for the detection of medial meniscal lesions in cranial cruciate-deficient stifle joints, aiming to avoid (minimally) invasive diagnostics in healthy menisci.

Investigating swollen joints in dogs and cats

Dogs and cats can present with acute or chronic swollen joint(s) which may or may not be associated with concurrent systemic signs of illness. Joint swelling may occur spontaneously, or with a history of trauma or previous surgery. Such cases can pose a diagnostic challenge, and understanding the underlying pathophysiology relating to the potential diagnoses is key to informing further investigations, achieving a prompt diagnosis and initiating appropriate early treatment. No diagnostic test should be interpreted in isolation, and every case requires thorough history taking, physical examination and selective use of blood testing and imaging. In conjunction with this, arthrocentesis in an invaluable tool suitable for general practice as well as referral practice. Practitioners should be encouraged to use arthrocentesis early in the diagnostic process to guide their management of patients with swollen joints, thereby optimising patient outcomes.

The epidemiology of osteochondrosis in an insured Swedish dog population

Osteochondrosis (OC) is a focal disturbance of endochondral ossification due to a failure of blood supply to the epiphyseal growth cartilage. In dogs, OC most commonly affects the shoulder joint, followed by the elbow, tarsal, and stifle joints. The condition is associated with clinical signs such as lameness and pain and the prognosis varies depending on the affected joint. Most epidemiologic studies of OC in dogs were performed over 20 years ago, and updated estimates of disease incidence are lacking. Therefore, the objectives of this study were to provide population-based estimates of the incidence rate, cause-specific mortality rate, and age at diagnosis of appendicular OC (AOC, including OC of the shoulder, elbow, stifle, and tarsal joints) and stifle and tarsal OC separately, using data from Agria Djurförsäkring in Sweden (2011–2016). Further, the study aimed to evaluate the risk of OC in subgroups divided by breed and sex and describe previous, concurrent, and subsequent diagnoses of the affected joint in dogs with stifle or tarsal joint OC. The study population included just over 600,000 dogs, of which 685 were affected by AOC. Stifle joint OC (n = 113) was more common than tarsal joint OC (n = 80). The incidence rate of AOC was 3.77 (95% confidence interval (CI): 3.49–4.07) cases per 10,000 dog-years at risk, while the incidence rate of stifle and joint tarsal OC was 0.64 (95% CI: 0.53–0.77) and 0.43 (95% CI: 0.34–0.54) cases per 10,000 dog-years at risk, respectively. All breeds at increased risk of AOC were large or giant, and male dogs had an increased risk of AOC compared to female dogs (RR 1.76, 95% CI: 1.50–2.07, p < 0.001). The median age at first diagnosis during the study period was 0.74 (0.32–11.5) years for AOC, 2.62 (0.45–8.82) years for stifle joint OC, and 0.73 (0.35–7.35) years for tarsal joint OC. Of the dogs with stifle or tarsal joint OC, 30.2% and 15.0% had a previous diagnosis of stifle/tarsal joint pain or other unspecific clinical signs, respectively, and 13.8% of the dogs with stifle joint OC suffered subsequent cruciate ligament rupture. Osteochondrosis was the most common reason for euthanasia in the affected dogs. In total, 77 dogs were euthanised due to AOC during the study period.

Development and Validation of an Examination Protocol for Arthroscopic Evaluation of the Temporomandibular Joint in Dogs.

Due to the previously limited intra-articular diagnostic possibilities of the canine temporomandibular joint, an examination protocol for the canine temporomandibular joint (TMJ) was developed and tested in this study using a needle arthroscope. In total, the discotemporal (DTJ) and discomandibular (DMJ) joint compartments of 32 animals (64 TMJs) were examined arthroscopically. During the examinations, 15 anatomical landmarks per joint side were evaluated in regard to their visibility and accessibility. All arthroscopies were performed by the same examiner and the same assistant to ensure standard methods were applied. The examination procedure which was developed here proved to be a reliable tool for examining this joint. The 15 anatomical landmarks that were to be examined could be reliably visualised and assessed in all TMJs with a certainty of 86% to 100% by both observers. This tool provides clinicians with a reliable examination aid for everyday practice and ensures the comparability of results. In the future, this could provide an opportunity to better diagnose and treat TMJ pathologies.

The technique of transosseous osteosynthesis in traumatic dislocation of the femur in the hip joint in dogs

At the Ilizarov Centre, various techniques of transosseous osteosynthesis of the hip for traumatic dislocations of the femoral head have been developed and introduced into veterinary practice. Clinical use of external fixation has demonstrated both advantages and disadvantages of a number of techniques. In order to optimize, while preserving the anatomical structures of the joint, some changes in the technique were made. The technique with a hinged connection between the external supports of the pelvis and thigh has found application to a greater extent. The hinged connection of the pelvic and femoral supports was replaced with an immobilizing structure, and the hip fixation became less traumatic. 20 dogs of different breeds and different sizes were operated on, using the proposed optimized technique. To fix the hip, transosseous osteosynthesis of the pelvis according to Ilizarov and external osteosynthesis of the femur were performed. Transosseous osteosynthesis was performed no later than 3 days after injury. Immobilization of the hip was performed within the periods of 21 to 35 days. The assessment of the functions of the pelvic limbs was determined by clinical research methods. A detailed description of the technique for performing external fixation of the hip is provided in the article. The good results of using this technique with restoration of the functions of the pelvic limb have been clinically confirmed. Scientific data on experimental modeling of arthroses are presented and temporary stabilization of the joint isjustified. The main advantage of the proposed technique is short-term immobilization of the hip in a physiological position without compression with maintaining the blood supply to the femoral head and in conformity with the viability of the articular cartilage.

Goniometric measurements of the femoral joint in dogs with hip dysplasia

Canine hip dysplasia is one of the most common orthopedic dieseases presents in most breeds of dogs but more prevalent in large breeds. Clinical examination through tests such as Ortolani, Barlow, and Bardens, alongside with radiological, tomographic, magnetic resonance, and ultrasonographic examinations, are the only methods for screening and diagnosing canine hip dysplasia. Canine hip dysplasia can lead to other musckuloskeletal diseases, with the most common ones being cruciate ligaments tear and spinal conditions such as IVDD or degenerative myelopathy. To assess hip changes, it is recommended that the patient to be heavily sedated, and the standard exposure will be with the hips in forced extension. Among knee conditions related to hip dysplasia, the most commonly reported are patellar luxation, partial cranial cruciate ligament rupture, and osteoarthritic changes. A study conducted on 65 dogs found concurrent hip dysplasia and patellar luxation in 28% of cases. Clinical goniometry is an objective and non invasive method of measuring joint angles, allowing for the assessment of the normal range of joint movements. This method can indicate the severity of joint pathology. Currently, goniometry is often used in the field of imaging and it can be an important element in assessing the musculoskeletal system. The aim of this paper is to evaluate the effectiveness of goniometric measurements at the knee and hip joint levels in dogs with hip dysplasia and if there is a correlation. A total of 10 dogs from varying breeds of dogs aging from 1 to 3 years old, were deeply sedated in order to measure perform the x-rays in ventro-dorsal hip extended view for measuring the Norberg angle (Na), anatomic Latero-Proximal Femoral Angle (aLPFA), anatomic Latero-Distal Femoral Angle (aLDFA), mechanical Latero-Distal Femoral Angle (mLDFA), mechanical Latero-Proximal Femoral Angle (mLPFA). All patients were part of the clinical cases present in our department and the written consent of the owners was obtained for each dog. Norberg and femoral angles were measured within the local DICOM viewer and the statistical analysis was performed with IBM SPSS Statistics. All images were reviewed by an ECVDI resident, a radiology professor and a radiology intern. All patients within our study had a Na under the reference value of 105º. All the femoral angles were within limits regarding their normal values. We conclude that there is not a signicative relation between the Na and the goniometric values obtained, most likely because of other factors that are influencing these measurements (ex. breed variations, femoral slightly rotation, muscle contracture due to poor anesthesia management, other musculoskeletal genetic disorders etc.). Further research on a more relevant statistical sample is recommended, in order to determine the normal goniometric values and the changes that appear in case of hip dysplasia.

Three-Dimensional Volume Rendering in Computed Tomography for Evaluation of the Temporomandibular Joint in Dogs.

Based on computed tomography (CT) images, volume rendering was used to obtain a three-dimensional representation of data (3DVR). The aims of this study included: describing the bone anatomy of the temporomandibular joint (TMJ) of dogs; comparing the TMJs of each dog by skull type and age; comparing 3DVR images with three-standard-plane CTs; assessing soft tissues adjacent to the TMJ and assessing pathological cases. Multidetector computed tomography scans of bilateral TMJs of 410 dogs were observed. From a ventral view, slight displacements in the positions of the skulls were seen, whereas from a caudal view, differences in amplitude of the articular space were observed. Dolichocephalic and mesaticephalic dogs showed more similar TMJ features than brachycephalic dogs. The shape of the TMJ bones were irregular in dogs under 1 year old. The 3DVR images related to the three-standard-plane CT improved the overall comprehension of the changes in the articular space amplitude and condylar process morphology. The fovea pterygoidea, mandibular fossa and retroarticular process were perfectly shown. A better spatial situation of adjacent soft tissues was obtained. The 3DVR represents an ancillary method to the standard-plane CT that could help in the understanding of the anatomy and diagnoses of different pathologies of the TMJ in dogs.

Anatomical study of stifle joint in dogs

The stifler is one of the hindlimb joints, described as complicated join consisting of many structures that organized in accurate way to support and stabilize body and hindlimb during the movement. The stifle joint of dogs, equivalent to the knee joint in the human, is a complex composition comprising the tibia, patella femur, menisci, caudal and cranial cruciate ligaments, lateral and medial collateral ligament, also surrounding muscles like hamstring and quadriceps muscles. The long bones (tibia and femur) form this joint, while patella sits in front of it to protect it. The two C-shaped menisci act as shock absorbers, and the supporting ligaments including collateral and cruciate provide stability to the joint. The surrounding muscles, including the quadriceps and hamstring muscles, help to extend and flex the joint, respectively. Together, these structures work in harmony to allow for the complex movement of dogs’ stifle joint.&#x0D; Understanding the anatomical features of the stifle joint in dogs is important for diagnosing and treating injuries or conditions that affect this complex joint

Instantaneous center of rotation in the canine femorotibial joint: Ex vivo assessment of a tool to evaluate joint stabilization surgeries

Cranial cruciate ligament rupture is a common cause of femorotibial joint instability in the dog. Numerous techniques including several tibial osteotomies have been described for stabilization, but there is no current consensus on the best method. The instantaneous center of rotation (ICR) can aid investigations of pathological joint movement, but its use is problematic in the femorotibial joint due to combined rotation and translation during flexion and extension. Using fluoroscopic images from an earlier cadaveric study of canine joint stability, an interpolation method was used to create repeatable rotational steps across joint situations, followed by least squares approximation of the ICR. The ICR in intact joints was located mid-condyle but displaced significantly (P < 0.001) proximally following cranial cruciate ligament transection and medial meniscal release. Individual joints appear to respond differently to destabilization. Triple tibial osteotomy partially restored ICR location during early movement from flexion to extension. Joint instability significantly altered the proportions of rolling and gliding movement at the joint surface (P < 0.02), which triple tibial osteotomy partially improved. While triple tibial osteotomy restores joint stability ex vivo and clinically, normal biomechanics of the joint are not restored. The methods described here may prove useful for comparison of osteotomy techniques for stabilization of the cranial cruciate ligament deficient femorotibial joint in dogs.

Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs.

This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate-PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Development of Real-Time Kinematic Magnetic Resonance Imaging (kMRI) Techniques for Studying the Kinematics of the Spine and Joints in Dogs-Preliminary Study on Cadavers.

Simple SummaryMany orthopedic and neurological pathologic conditions can potentially lead to or be affected by joint instability. Standard magnetic resonance imaging, as a static technique that examine joints and body parts in functional rest, can underestimate or overlook key diagnostic findings. As a result, kinematic magnetic resonance imaging techniques were developed to evaluate joints and body parts under stress and load conditions or during movement. In human medicine, the real-time acquisition technique is one of the modalities for acquiring kinematic magnetic resonance imaging, and has gained popularity in recent years. This proof-of-concept study was designed to test the feasibility of real-time acquisition techniques in veterinary medicine for the first time. Based on the results of this preliminary cadaveric study, real-time kinematic magnetic resonance imaging may be a feasible and valuable procedure to be applied to the canine cervical spine and stifle joints. Moreover, given the ease of execution and the concise duration of acquisitions, it could be applied in a regular standard protocol MRI with little additional effort, risk, and cost. In this proof-of-concept study, a good visualization of the canine cervical spine and stifle joint was achieved, showing the potential of real-time acquisition techniques for clinical and research applications.Kinematic MRI (kMRI) is a novel human imaging technique that couples the excellent soft tissue contrast and multiplanar capabilities of traditional MRI with kinematic potential. The study’s goals are: (1) testing the feasibility of spinal cord and joints real-time kMRI; and (2) evaluating the quality of these kinematic studies as a new diagnostic option in veterinary medicine. Standard and real-time kinematic MRI were performed on cervical spine, elbow, and stifle joints of seven cadavers. Studies were repeated after a surgical insult aimed to create a certain degree of joint instability. A total of 56 MRI were performed—7 cervical spinal tracts, 3 elbow joints, and 4 stifle joints were examined. The technique was feasible in all the three regions examined. The images were considered of excellent quality for the stifle joint, good to fair for the cervical spine, whereas two of three elbow studies were considered to have unacceptable image quality. Additionally, real-time kMRI provided good to excellent information about stifle instability. Therefore we consider kMRI a promising technique in veterinary medicine. Further studies and an in vivo setting are needed to increase the quality of the kMRI images, and to fully evaluate clinical usefulness.

The use of subchondral bone topography to approximate the center of rotation of the elbow joint in dogs.

The aim of this study was to compare the approximate center of rotation in normal and diseased elbows in dogs. Cross-sectional study SAMPLE POPULATION: Computer tomography scans of nine dogs with unilateral fragmented medial coronoid process (FMCP). A board certified radiologist confirmed that each dog had unilateral FMCP, and a normal contralateral elbow. Digital 3D models of all elbow joints were uploaded into a surgical planning software package. Four axes approximating the center of rotation (COR) of elbow joints were generated using five geometric shapes based on subchondral topography of the humeral condyle radius and ulna. Images showing the locations where axes exited the medial and lateral cortex of the humeral condyle were captured and imported into a second software package, for measurement of distances between exit points and the origin of a system of axes. In normal joints 20/27 (74%) axes exited the medial cortex, and 25/27 (93%) axes exited the lateral cortex cranial and distal to the medial and lateral epicondyles, respectively. In diseased joints 22/27 (81%) axes exited medial cortex and 19/27 (70%) axes exited the lateral cortex, caudal and distal to the medial and lateral epicondyles, respectively. Based on CT- derived geometry, the COR of elbow affected with FMCP was generally more caudal than normal. External landmarks approximating the location of the elbow COR are provided, and while not validated, may assist in planning, creation, and assessment of procedures for FMCP.

Synovial membrane-derived mesenchymal progenitor cells from osteoarthritic joints in dogs possess lower chondrogenic-, and higher osteogenic capacity compared to normal joints

BackgroundSynovial membrane-derived mesenchymal progenitor cells (SM-MPCs) are a promising candidate for the cell-based treatment of osteoarthritis (OA) considering their in vitro and in vivo capacity for cartilage repair. However, the OA environment may adversely impact their regenerative capacity. There are no studies for canine (c)SM-MPCs that compare normal to OA SM-MPCs, even though dogs are considered a relevant animal model for OA. Therefore, this study compared cSM-MPCs from normal and OA synovial membrane tissue to elucidate the effect of the OA environment on MPC numbers, indicated by CD marker profile and colony-forming unit (CFU) capacity, and the impact of the OA niche on tri-lineage differentiation.MethodsNormal and OA synovial membrane were collected from the knee joints of healthy dogs and dogs with rupture of the cruciate ligaments. The synovium was assessed by histopathological OARSI scoring and by RT-qPCR for inflammation/synovitis-related markers. The presence of cSM-MPCs in the native tissue was further characterized with flow cytometry, RT-qPCR, and immunohistochemistry, using the MPC markers; CD90, CD73, CD44, CD271, and CD34. Furthermore, cells isolated upon enzymatic digestion were characterized by CFU capacity, and a population doublings assay. cSM-MPCs were selected based on plastic adherence, expanded to passage 2, and evaluated for the expression of MPC-related surface markers and tri-lineage differentiation capacity.ResultsSynovial tissue collected from the OA joints had a significantly higher OARSI score compared to normal joints, and significantly upregulated inflammation/synovitis markers S100A8/9, IL6, IL8, and CCL2. Both normal and OA synovial membrane contained cells displaying MPC properties, including a fibroblast-like morphology, CFU capacity, and maintained MPC marker expression over time during expansion. However, OA cSM-MPCs were unable to differentiate towards the chondrogenic lineage and had low adipogenic capacity in contrast to normal cSM-MPCs, whereas they possessed a higher osteogenic capacity. Furthermore, the OA synovial membrane contained significantly lower percentages of CD90+, CD44+, CD34+, and CD271+ cells.ConclusionsThe OA environment had adverse effects on the regenerative potential of cSM-MPCs, corroborated by decreased CFU, population doubling, and chondrogenic capacity compared to normal cSM-MPCs. OA cSM-MPCs may be a less optimal candidate for the cell-based treatment of OA than normal cSM-MPCs.

The Effect of Increasing Tibial Tuberosity Advancement and Quadriceps Muscle Force on Cranial Translation of the Tibia in the Cranial Cruciate Deficient Stifle Joint in Dogs.

BackgroundCranial cruciate ligament (CCL) disease is a well-known pathology that generates both rotational and translational instability of the stifle joint that leads to osteoarthritis in dogs. Tibial tuberosity advancement (TTA) is a common surgical technique used to dynamically neutralize the tibiofemoral shear forces to achieve stifle joint stability. However, significant persistent instability has been documented in clinical cases. The purpose of this study was to evaluate the effect of increasing quadriceps load, increasing tibial tuberosity advancement, and increasing joint flexion angle on the cranial translation of the tibia relative to the femur in the cranial cruciate ligament deficient stifle joint.Methods and ResultsSix cadaveric hind limbs were collected from six healthy mixed breed dogs of medium build and prepared for biomechanical testing. The specimen was placed into a custom-made joint testing machine, and translation of the tibia relative to the femur was measured at stifle angles of 135°, 120°, and 105°. Cranial tibial thrust was generated by applying a vertical load to the metatarsal pad and the quadriceps muscle was simulated with loads of 0, 5, and 10 kg applied to the patella via a system of weights and pulleys. All specimens were tested with the CCL intact and cut, both of which served as controls. The tibial tuberosity was then advanced using both 6 mm and 9 mm cages, and the specimen was tested using the identical technique. Each specimen was loaded to failure by increasing the load applied to the pes until the sudden marked cranial translation of the tibia. Tibial tuberosity advancement with an applied quadriceps load was successful in limiting cranial tibial translation in 54/62 tests. Under similar loading conditions, TTA failed to limit cranial translation in 8 tests. The failures occurred at all angles of flexion examined. In the cases that failed cranial translation could be limited by either increasing the quadriceps load or increasing the amount of tibial tuberosity advancement.ConclusionThis study showed that TTA with an applied quadriceps load is effective at decreasing cranial tibial translation at functional joint angles.

Thermographic Evaluation of the Duration of Skin Cooling After Cryotherapy in Dogs Following Tibial Plateau Leveling Osteotomy Surgery.

ObjectiveTo evaluate the duration of cooling after cryotherapy on the skin over stifle joints in dogs after tibial plateau leveling osteotomy (TPLO) surgery using thermography.Materials and MethodsSeventeen client-owned dogs of various breeds were enrolled in the study. Dogs underwent TPLO surgeries, and on the next day, thermal imaging was performed on the operated stifle prior to cryotherapy for baseline. Orthogonal views were repeated at 30-min intervals until the skin over the stifle had thermally equilibrated. An ice pack was applied for 20 min on the medial and lateral aspects of the stifle. Each stifle was then re-imaged every 15 min for the first 60 min then every 30 min subsequently until the temperature was within 1°C of the pre-cryotherapy temperature.ResultsMean skin temperature of the medial view showed no significance difference compared to baseline value at 45 min after cryotherapy was discontinued and after 60 min for the lateral and cranial views. Mean skin temperature was overall higher in the medial view compared to the lateral and cranial during the rewarming period (except immediately after cold application). Mean skin temperatures of all views combined showed a significant decrease in temperature during cryotherapy application, with a slow increase until a plateau was reached after 45 min of rewarming.Conclusions and Clinical RelevanceDogs undergoing TPLO for cranial cruciate ligament injury showed quicker rewarming period of superficial tissues compared to previous studies. Cryotherapy is a beneficial modality to reduce superficial tissue temperature in dogs undergoing TPLO, acknowledging that these dogs may require more frequent cryotherapy post-operatively due to more rapid rewarming time compared to dogs without surgery.

Personalized endoprostheses for the proximal humerus and scapulohumeral joint in dogs: Biomechanical study of the muscles’ contributions during locomotion

Osteosarcoma represents one of the most common bone tumours in dogs. It commonly occurs in the proximal humerus, the most affected anatomic site. Until recently, amputation or limb-sparing surgery leading to an arthrodesis coupled with chemotherapy were the only available treatments, but they often lead to complications, reduced mobility and highly impact dog’s quality of life. Prototypes of both articulated and monobloc (no mobility) patient-specific endoprostheses have been designed to spare the limb afflicted with osteosarcoma of the proximal humerus. This study focuses on the biomechanical effects of endoprostheses and shoulder muscle kinematics. For each of the endoprosthesis designs, a minimal number of muscles needed to ensure stability and a certain degree of joint movement during walking is sought. A quasi-static study based on an optimization method, the minimization of the sum of maximal muscle stresses, was carried out to assess the contribution of each muscle to the shoulder function. The identification of the most important muscles and their impact on the kinematics of the prosthetic joint lead to an improvement of the endoprosthesis design relevance and implantation feasibility.

The Diagnostic Yield of Cone-Beam Computed Tomography for Degenerative Changes of the Temporomandibular Joint in Dogs.

Degenerative changes of the temporomandibular joint (DTMJ) may be diagnosed via cone - beam computed tomography (CBCT). However, despite advancement in CBCT imaging, correlation of DTMJ features identified on CBCT with gross and histological findings is currently limited. This study aimed to correlate CBCT findings of DTMJ of dogs with gross and histopathologic changes. Temporomandibular joints (TMJ) (n = 38) from fresh cadaver heads of asymptomatic dogs (n = 19) were examined radiologically, macroscopically, and microscopically. Association of CBCT - detected DTMJ changes with gross and histological findings were statistically evaluated via kappa statistics and ordinal logistic mixed-effects models. The radiological changes observed on CBCT included joint space narrowing, subchondral/cortical bone changes (i.e., erosions or lysis), osteophytes, and subchondral bone sclerosis. Upon macroscopic evaluation, the majority of examined specimens had mild changes with cartilage defects and osteophytes affecting <10% of the total articular surface area. Histopathologic changes comprised splitting and degeneration of the fibrous cartilage layers, subchondral bone exposure, subchondral bone sclerosis, focal subchondral bone lysis, and occasional cell death. Subchondral sclerosis was the most prevalent finding radiologically and histologically with a fair to excellent agreement. Importantly, the more severe the TMJ degenerative changes, the higher the agreement between CBCT and histology. Based on the correlative results of statistical analysis, CBCT was found to be a suitable modality to evaluate DTMJ.

Calcaneotibial screws for immobilisation of the tarsocrural joint of dogs in extension: effect of the angle of screw placement on the force to failure in a canine cadaveric model

ABSTRACT Aims To compare the force to failure under axial loading of a calcaneotibial screw placed approximately perpendicular to the tibia with that of a screw placed perpendicular to the calcaneus, when used to immobilise the tarsus in an ex vivo canine model. Methods Twelve pairs of cadaveric hindlimbs from large breed dogs, without orthopaedic or soft tissue disease, were prepared by transecting the limb at the level of the stifle and stripping the limbs of all musculature from the stifle to mid-metatarsus, including removal of the common calcaneal tendon from all limbs. The limbs in each pair were randomly assigned to receive a calcaneotibial screw placed perpendicular to the long axis of either the calcaneus (C group) or the tibia (T group) with the tarsus in full extension. The distal limb was potted in resin and the proximal tibia was pinned to allow biomechanical testing in compressive loading. Testing was performed to apply an axial load using a material testing machine in a proximodistal direction through the tibia, advancing at a rate of 10 mm/second. The force to failure was recorded in kN and compared between groups. Results The median force to failure of the C group was 0.86 (min 0.50; max 1.64) kN which was higher than the T group which had a median force to failure of 0.74 (min 0.26, max1.05) kN (p = 0.004). All modes of failure were by screw pull-out. Conclusions A calcaneotibial screw placed at an angle approximately perpendicular to the long axis of the calcaneus, has a higher force to failure under axial loading than a calcaneotibial screw that is placed at an angle approximately perpendicular to the tibia, in a canine cadaveric model. Clinical relevance A temporary calcaneotibial screw is a common method of immobilising the tarsus in extension to protect primary repair of a common calcaneal tendon injury. Placing a calcaneotibial screw perpendicular to the calcaneus may be a more reliable option for immobilisation of the tarsus to protect a common calcaneal tendon repair compared to screws placed perpendicular to the tibia. However extrapolation of these results into a clinical setting requires caution.

Locking compression plates versus locking plates for tibial plateau levelling osteotomy in dogs: progression of osteoarthritis, bone healing score and lameness degree

BackgroundThe partial or complete cranial cruciate ligament rupture is a common skeletal disease affecting the stifle joint in dogs. The tibial plateau levelling osteotomy, performed with several synthesis systems, changed the approach to its treatment in dogs. The aim of this study was to compare two types of fixation implants, locking compression system and locking system, evaluating radiographically the progression of osteoarthritis of the stifle joint in dogs with complete cranial cruciate ligament deficiency treated surgically with tibial plateau levelling osteotomy. Moreover, we evaluated bone healing and lameness scores to show biomechanical effects by the implant used. Twenty-eight dogs, who met the inclusion criteria, were divided into two groups. Group A: 14 dogs treated using locking compression plates; Group B: 14 dogs treated using locking plates. Radiographic osteoarthritis scores were evaluated up to 1 year following tibial plateau levelling osteotomy. At each visit, animals were clinically and radiographically assessed. Each dog was evaluated before (T0) and after two (T2) and twelve (T12) months after the surgery. At T2 the stage of bone healing was evaluated. The clinical follow up was performed before the surgery and at 10, 15 and 20 days after the surgery, grading the lameness at walk and trot.ResultsAn increase in osteoarthritis score at T12 versus T0 in both groups was detected. A decrease of the lameness score was observed in Group A versus Group B. The healing score system at T2 showed a lower score in Group A versus Group B.ConclusionsThe osteoarthritis score following tibial plateau levelling osteotomy did not differ when comparing the two different fixation systems. The locking compression system allowed a more rapid functional recovery of the limb and a quicker bone healing than the locking system. Locking compression system should be carefully considered for dogs subjected to tibial plateau levelling osteotomy surgery, because it may reduce the recovery time.

The microarchitecture of the tissues of the shoulder joint in dogs

Up to the present time practically not studied the peculiarities of formation of cartilage in the various compartments of the shoulder joint in dogs, as well as zones of least resistance joints in General. Available studies mainly use visual diagnostic methods, without applying morphological and morphometric. There is no information about age-related cytomorphological transformations occurring in the joint in normal and pathological conditions. In this regard, the aim of our study was to determine the zone of risk of damage to the shoulder joint in dogs. Studies were conducted on dogs and cadaver material, selected from giant, large and mediumsized breeds. Arthroscopic studies of dogs were performed, as well as light microscopy of histological sections of freshly treated samples of joint tissues. As a result of trauma to the joint is transformed physiological synovial folds in sklerozirovanie a pathological form that occurs in German shepherd dogs over 5 years of age in 60% of cases. The process of mineralization of the matrix and the appearance of multiple foci of ossification occurs asynchronously in the cartilage of the head of the humerus and the articular cavity of the scapula. Osteoplastic processes in the area of articulation occur unevenly. Cartilage coating of the articular surface of the shoulder blade is characterized by a more uniform distribution than the articular rotation of the humerus head. The zones of risk of damage to the structures of the shoulder joint in dogs were determined. These include: cranial and medial compartments of the joint, the caudal area of the cartilaginous coating of the humerus, the caudal area of the articular surface of the scapula cavity. The data obtained make up for the information about the diagnosis and risk factors in the development of shoulder joint pathologies in dogs of large and giant breeds. They should be used in clinical diagnosis and surgery of the musculoskeletal system in animals.