Comparison of the distraction index and Norberg angle with radiographic grading of canine hip dysplasia.

The Orthopedic Foundation for Animals (OFA) radiographic grading system stands as a well-established benchmark for categorizing hip dysplasia in canines. Although more objective techniques to quantify early hip laxity in young dogs, such as the Norberg angle (NA) and distraction index (DI), have been documented, there is a scarcity of published studies that directly compare these radiographic measures. The primary objectives of this prospective, analytical study were to assess and compare the NA and DI measures with OFA grades within a cohort of dogs. Thirty dogs (57 hip joints) were evaluated, with a mean age of 5.4 ± 2.9 years and a mean body weight of 34.3 ± 7.1 kg. The discriminative power of hip dysplasia for DI and NA used OFA as a reference were compared by multivariate discriminant analysis test. Using the DI (≤0.3) 12 joints were classified as normal, using NA (≥105°) 24 joints and using OFA (≤3) 29. When comparing the discriminant power of NA with OFA resulting similar (P = .8324) with correct classifications of 81% using cross validation, however, the discriminant power of dysplasia of the DI resulted significantly greater (P = .0034) than OFA with correct classifications of only 59% using cross-validation, consequently it was possible determined that of 29 patients with OFA ≤ 3, 20 had DI > 0.3. These findings demonstrated that phenotypic healthy dogs according to OFA grading can present passive hip joint laxity, as demonstrated by radiographic evaluation with distraction. Furthermore, DI can contribute to the screening of CHD when evaluated in conjunction with OFA grading.

Quantifying the Stress in Stress Radiographs to Determine Sufficient Laxity of the Coxofemoral Joint: A Canine Hip Dysplasia Cadaveric Study.

OBJECTIVE: While it has been known for a long time that laxity in the hip joint is the primary cause of degenerative changes later on in canine hip dysplasia, limited data are available on the fundamental characteristics that define the procedure used to quantify this. The aim of this study was to evaluate the force-laxity relation to assess the repeatability of repeated cycles of stress on the hip joint and determine the force necessary tomeasure a sufficient proportion of laxity present in hip joints. MATERIALS AND METHODS: Thirty-four canine cadavers underwent a radiographic protocol including stress radiographs with increasing force using the Vezzoni modified Badertscher distension measuring device (VMBDmD). Three dogs underwent five repeat examinations. The laxity index (LI) and osteoarthritis were scored. RESULTS AND CONCLUSION: The curves and the maximal LI (LImax) were not significantly influenced by osteoarthritis, weight, gender, and side. The position of the VMBDmD influenced the curve but not the LImax. The force-laxity curve itself and the LImax were repeatable, which indicated that it did not cause permanent damage to the joint and also confirmed the practicability of the procedure. Ninety percent of hip joints reached sufficient laxity at a force of 95.32 N, which is realistically achievable. Further studies are necessary before extrapolating these results to patients and to further enlighten the biomechanics of stress radiographs.

Mechanical osteoarthritis of the hip in a one medicine concept: a narrative review.

Human and veterinary medicine have historically presented many medical areas of potential synergy and convergence. Mechanical osteoarthritis (MOA) is characterized by a gradual complex imbalance between cartilage production, loss, and derangement. Any joint instability that results in an abnormal overload of the joint surface can trigger MOA. As MOA has a prevailing mechanical aetiology, treatment effectiveness can only be accomplished if altered joint mechanics and mechanosensitive pathways are normalized and restored. Otherwise, the inflammatory cascade of osteoarthritis will be initiated, and the changes may become irreversible. The management of the disease using non-steroidal anti-inflammatory drugs, analgesics, physical therapy, diet changes, or nutraceuticals is conservative and less effective. MOA is a determinant factor for the development of hip dysplasia in both humans and dogs. Hip dysplasia is a hereditary disease with a high incidence and, therefore, of great clinical importance due to the associated discomfort and significant functional limitations. Furthermore, on account of analogous human and canine hip dysplasia disease and under the One Medicine concept, unifying veterinary and human research could improve the well-being and health of both species, increasing the acknowledgement of shared diseases. Great success has been accomplished in humans regarding preventive conservative management of hip dysplasia and following One Medicine concept, similar measures would benefit dogs. Moreover, animal models have long been used to better understand the different diseases' mechanisms. Current research in animal models was addressed and the role of rabbit models in pathophysiologic studies and of the dog as a spontaneous animal model were highlighted, denoting the inexistence of rabbit functional models to investigate therapeutic approaches in hip MOA.

A shape memory alloy implant can be an effective surgical treatment in the atlantoaxial joint stabilization using rabbits as substitutes for toy-breed dogs.

OBJECTIVE: To investigate the feasibility of using shape memory alloy (SMA) implants for atlantoaxial joint stabilization using a rabbit model as a substitute for canines. ANIMALS: 20 rabbit cadavers. METHODS: We prepared rabbit cadavers from the middle of the skull to the third cervical vertebra. The vertebral body and canal sizes of the atlas and axis were compared using CT data from rabbits, normal dogs, and dogs with atlantoaxial instability (AAI) to assess the feasibility of using rabbits as substitutes for toy-breed dogs. The shape memory alloy (SMA) implants were designed to stabilize the atlantoaxial joint without compromising the spinal canal passage for safety and were classified into SMA-1 and SMA-2 based on their design. To evaluate the strength, the ventrodorsal force was measured with atlantoaxial ligaments intact, after removing the ligaments, and after applying conventional wire or SMA implants to stabilize the atlantoaxial joint. The time taken for implant application was measured. RESULTS: No significant difference in vertebral body size of the atlas and axis was observed. A significant difference in vertebral canal size was observed between the animals. In biomechanical testing, the SMA-2 implant provided more stabilization, while the SMA-1 implant had lower strength than the conventional method using wires. The application time of wire was the longest, while that of SMA-1 was the shortest. CLINICAL RELEVANCE: SMA implants provide comparable strength and demonstrate superior efficacy compared to conventional dorsal wire fixation of atlantoaxial stabilization. Therefore, SMA implants can be an effective surgical option for AAI.

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.

Patellar development after patella instability and early reduction in growing rabbits.

BACKGROUND: Patella-shaped disorder has been considered as a predisposing factor for patella instability. But the influence of early patella reduction for patellar development remains unclear. This study aimed to evaluate whether early operation in patella instability could improve patella morphology in growing rabbits. METHODS: Fifty rabbits (1-month-old) were included in the study. The control group underwent no surgical procedures. The two experimental groups (reduction group and non-reduced group), underwent medial soft tissue restraint release surgery. The reduction group, rabbits underwent the medial soft tissue sutura surgery in order to stabilize the patella 2 months after release surgery. The non-reduced group, rabbits did not undergo suture surgery. Computed Tomography (CT) scans analysis in two experimental endpoints (2, 5 months after release surgery) were selected to evaluate the transverse diameter, thickness, Wiberg index and Wiberg angle. Gross observation was conducted to assess morphological changes of the patella. RESULTS: CT scans showed significant difference in the mean transverse diameter, Wiberg angle between the two experimental groups and the control group 2 months after release surgery. 5 months after release surgery, the indices of patella were found no statistically difference in the reduction group versus the control group. However, the transverse diameter, Wiberg angle in the non-reduced group were significantly differences than that in the reduction group (P < 0.05). Gross observation showed a flattened articular surface of the patella in the non-reduced group. CONCLUSIONS: The results indicated that patella instability may lead to patella-shaped disorder, showing a flattened morphology. Early patella reduction can improve the patella morphology in growing rabbits.

Stress radiographic assessment of collateral ligament constraints on the feline tarsocrural joint.

INTRODUCTION: This cadaveric study describes the collateral ligament constraints on the feline tarsocrural joint using stress radiography. METHODS: Thirty-six feline cadaveric hindlimbs free of orthopaedic disease were placed in a custom-made jig and controlled stress radiography was performed before and after transection of one, or both collateral ligaments. Changes in varus and valgus deviation and pronation and supination were measured at three limb angles (extension, 120o flexion and 90o flexion). RESULTS: There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulocalcaneal ligament at all limb positions (extension: 41%, 120°: 78%, 90°: 63%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the fibulotalar ligament at extension (14%). There was a significant positive percentage change in the mean angle of varus deviation after transection of both fibulocalcaneal and fibulotalar ligaments at all limb positions (extension: 58%, 120°: 67%, 90°: 67%), and in the mean angle of valgus deviation (100%) and supination (89%) at 90 degrees flexion. There was a significant positive percentage change in the mean angle of valgus deviation after transection of the tibiocentral ligament at all limb positions (extension: mean 79%, 120°: 43%, 90°: 49%) and the mean angle of pronation at 120 degrees flexion (10%). There was a significant positive percentage change in the mean angle of varus deviation after transection of the tibiotalar ligament at extension (11%) and at 90 degrees flexion (54%) and in the mean angle of pronation at all limb positions (extension: 11%, 120°: 19%, 90°: 32%). There was a significant positive percentage change in the mean angle of valgus deviation (extension: 255%, 120°: 172%, 90°: 176%) and pronation (extension: 58%, 120°: 134%, 90°: 76%) after transection of the tibiocentral and tibiotalar ligaments at all limb positions and in the mean angle of varus deviation at extension (13%) and 90 degrees flexion (69%). CONCLUSION: The medial collateral ligaments prevent against excessive valgus deviation and pronation, and the lateral collateral ligaments prevent against excessive varus deviation and supination. At 90 degrees flexion subluxation of the talus occurs on the ipsilateral side of the ligament injury resulting in an additional direction of instability.

Pilot study of the ultrasonographic examination of the intact and transected medial glenohumeral ligament in dogs.

Medial glenohumeral ligament injury is commonly reported during medial shoulder joint instability in dogs. Arthroscopy is considered the gold standard procedure, but it is invasive and requires distension of the joint. Ultrasonographic examination of the medial glenohumeral ligament has been studied as a possible, less invasive alternative to arthroscopy however it has not been considered a useful method of assessment due to the interference of the probe with the pectoral muscles. The aims of this prospective analytical randomized pilot study were to develop a standardized ultrasound protocol for visualizing the canine medial glenohumeral ligament and to compare goniometry and ultrasound findings in cadaver dogs with versus without transection of the medial glenohumeral ligament. Nine adult Beagle cadavers (18 shoulders) were used. The first six shoulders were used in a preliminary study to describe an ultrasound technique to identify the medial glenohumeral ligament. Arthroscopy was performed on the remaining 12 shoulders, with six randomly selected medial glenohumeral ligaments from these shoulders, transected during the procedure. Ultrasound examination was performed after each arthroscopic procedure by an ultrasonographer blinded to the patient group. Four medial glenohumeral ligaments (67%) were correctly identified during the preliminary study. Ultrasonographic examination failed to diagnose the transection of all six medial glenohumeral ligaments in the second part of the study. No difference was observed in the ligament thickness between the dogs with and without a transected medial glenohumeral ligament. Dogs with a transected medial glenohumeral ligament had a wider articular space compared to dogs without a transected ligament (P < 0.001), and an articular space wider than 8.2 mm was discriminatory of a transected medial glenohumeral ligament in all the shoulders. In conclusion, the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.

Treatment of Medial Shoulder Joint Instability by Stabilization with an Arthroscopically Guided Prosthetic Ligament: A Cadaveric Feasibility Study in Dogs.

OBJECTIVE: The aim of this study was to assess the feasibility and efficiency of an arthroscopically guided ligamentoplasty of the medial glenohumeral ligament to treat medial shoulder joint instability. STUDY DESIGN: Six Beagle cadavers were used (12 limbs). Both arms of the medial glenohumeral ligament were severed using arthroscopic guidance. Arthroscopically guided reconstruction of the ligament was performed. Threaded sutures were fixed with a bone anchor on the medial aspect of the glenoidal cavity of the scapula, passed through a humeral tunnel and finally tensioned with a suture button on lateral aspect of the humerus. Shoulder abduction angles were measured before and after the section of the medial glenohumeral ligament, and following the surgery. Two orthogonal radiographic projections and dissections were performed after each procedure to grade the placement of the implants. RESULTS: Surgical repairs were achieved in 10 out of 12 limbs. The abduction angles after repair with ligamentoplasty were not significantly different from the abduction angles measured before the section of the medial glenohumeral ligament. CONCLUSION: Arthroscopically guided ligamentoplasty with a scapular bone anchor and a humeral drilling tunnel is feasible in cadavers, and efficient to restore acutely shoulder abduction angle in a minimally invasive manner. Further clinical studies are required to assess in vivo results.

Comparison of two postoperative complication grading systems after treatment of stifle and shoulder instability in 68 dogs.

OBJECTIVE: (1) To adapt and apply the Clavien-Dindo (aCD) postoperative complication grading system to dogs experiencing complications following a single orthopedic procedure. (2) To compare the reliability of the Clavien-Dindo system to the Cook complication grading system. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Sixty-eight client-owned dogs. METHODS: Scenarios derived from complications following TightRope stabilization of the stifle and shoulder were graded by four ACVS-boarded surgeons using two systems; the Cook 3-point scale and the aCD 5-point scale. Because the aCD system distinguishes complications from outcomes ("sequelae" or "failure to cure"), two data sets were created: one with (n = 76) and without (n = 67) inclusion of "sequelae" and "failure to cure" cases. Interobserver reliability was evaluated using intraclass correlation coefficient (ICC) calculations. RESULTS: Seventy-six scenarios from 68 records were evaluated. The ICC of the aCD system was 0.620 consistent with moderate reliability. The reliability of the Cook system was good, with an ICC of 0.848. Exclusion of cases with "sequelae" or "failure to cure" resulted in excellent reliability of the aCD system (ICC = 0.975) and good reliability of the Cook systems (ICC = 0.857). CONCLUSION: The aCD grading system was less reliable than the Cook system when evaluating all cases but more reliable when evaluating cases of complications excluding "sequelae" and "failures to cure". CLINICAL SIGNIFICANCE: The Cook grading system is reliably good in grading postoperative complications in dogs. The aCD system can also be used to assess postoperative complications with excellent reliability but is less reliable when distinguishing complications from other postoperative outcomes.

Evaluation of Paraspinal Musculature in Small Breed Dogs with and without Atlantoaxial Instability Using Computed Tomography.

OBJECTIVE: The aim of this study was to evaluate differences in paraspinal musculature between dogs with and without atlantoaxial instability (AAI) using computed tomography scans. STUDY DESIGN: Retrospective multicentre study evaluating transverse reconstructed computed tomography scans of 83 small breed dogs (34 with and 49 without AAI) for the cross-sectional paraspinal musculature area at three levels (Occiput/C1, mid-C1, mid-C2). Ratio of moments, dorsal-to-ventral muscle-area ratios (d-v-ratio) and ratios of the dorsal and ventral musculature to C2 height (d-C2-ratio and v-C2-ratio) were evaluated for differences between groups using multivariate analysis of variance (p < 0.05) taking the head-neck position into account. RESULTS: Dogs with AAI showed a significantly lower d-v-ratio at levels 2 and 3, d-C2-ratio at level 2 and ratio of moments at all levels. When head-neck positions were analysed separately, ratio of moments was significantly lower in affected dogs at level 1 and 2. Also lower was d-C2-ratio at level 2, but only in flexed positioning. The head-neck position had a significant influence on ratio of moments and d-v-ratio at all three levels and on d-C2-ratio at level 1. CONCLUSION: Significant changes in muscle area were observed only for the hypaxial muscles at the C1 level, indicating a limited role of muscular adaption in AAI patients. Our results confirm an altered ratio of moments in dogs with AAI. The head-neck position has a significant impact and should be taken into account when evaluating spinal musculature.

Arthroscopic Caudal Cruciate Ligament Damage in Canine Stifles with Cranial Cruciate Ligament Disease.

OBJECTIVE: The aim of this study was to describe the arthroscopic changes to the caudal cruciate ligament (CdCL) in dogs with cranial cruciate ligament disease. STUDY DESIGN: Arthroscopic video recordings (n = 117) of the stifle with cranial cruciate ligament disease were reviewed. The extent of CdCL tearing was described. Signalment, palpable stifle stability and the presence of a meniscal tear were recorded. Pathology of the synovial joint and the synovium overlying the CdCL were scored at two time points.Two-way interactions were investigated (p < 0.05). Univariate analysis and a Wald test (p < 0.20) were performed. Factors were retained with a Wald test p < 0.05 or if a confounder, then a changing model coefficient >15%. A weighted kappa statistic was used to evaluate intraobserver agreement. RESULTS: Caudal cruciate ligament tearing was identified in 94% of stifles. Longitudinal tearing (76%) was the most common type of damage (45% partial, 31% full thickness). Synovitis was present in all joints and changes to the synovium overlying the CdCL were less frequently identified (67%).Synovitis was associated with the degree to CdCL tearing. Synovitis overlying the CdCL was associated with lower body weight and lower CdCL damage. CONCLUSION: Caudal cruciate ligament damage is common in dogs with cranial cruciate ligament disease and longitudinal tearing was the most common injury identified. Severity of joint pouch synovitis was positively correlated with the degree of CdCL damage and the portion of the CdCL not exposed to the synovium was unaffected. These findings suggest synovitis is likely a contributor to CdCL injury.

Influence of ventral fixation techniques on atlantoaxial joint fusion in canine models with dens partial resection.

We evaluated the completeness of bony fusion of the atlantoaxial joint (AAJ) through polymethylmethacrylate fixation (PMF) and atlantoaxial plate fixation (APF) using six canine models with dens partial resection. In both groups, the hydroxyapatite content at the AAJ was measured up to 7 months postoperatively using quantitative computed tomography. Histological assessment revealed fibrous fusion in the PMF group. Meanwhile, in the APF group, only one dog achieved fibrous fusion, whereas the remaining three showed bony fusion. To our knowledge, this study was the first to evaluate AAJ fusion histologically after PMF and APF. The present study demonstrates that PMF and APF may stabilize the AAJ without clinical complications. Therefore, PMF and APF are clinically useful fixation methods for atlantoaxial instability.

Determination of cutoff values on computed tomography and magnetic resonance images for the diagnosis of atlantoaxial instability in small-breed dogs.

OBJECTIVE: To determine cutoff values for the diagnosis of atlantoaxial instability (AAI) based on cross-sectional imaging in small-breed dogs. STUDY DESIGN: Retrospective multicenter study. SAMPLE POPULATION: Client-owned dogs (n = 123) and 28 cadavers. METHODS: Dogs were assigned to three groups: a control group, a "potentially unstable" group, and an AAI-affected group, according to imaging findings and clinical signs. The ventral compression index (VCI), cranial translation ratio (CTR), C1-C2 overlap, C1-C2 angle, atlantoaxial distance, basion-dens interval, dens-to-axis length ratio (DALR), power ratio, and clivus canal angles were measured on CT or T2-weighted magnetic resonance (MR) images. Receiver operating characteristic (ROC) analysis was performed to define cutoff values in flexed (≥25°) and extended (<25°) head positions. RESULTS: Cutoff values for the VCI of ≥0.16 in extended and ≥0.2 in flexed head positions were diagnostic for AAI (sensitivity of 100% and 100%, specificity of 94.54% and 96.67%, respectively). Cutoff values for the other measurements were defined with a lower sensitivity (75%-96%) and specificity (70%-97%). A combination of the measurements did not increase the sensitivity and specificity compared with the VCI as single measurement. CONCLUSION: Cutoff values for several imaging measurements were established with good sensitivity and specificity. The VCI, defined as the ratio between the ventral and dorsal atlantodental interval, had the highest sensitivity and specificity in both head positions. CLINICAL SIGNIFICANCE: The use of defined cutoff values allows an objective diagnosis of AAI in small-breed dogs. The decision for surgical intervention, however, should remain based on a combination of clinical and imaging findings.

Comparison of cross-sectional area and fat infiltration of suboccipital muscles between normal dogs and dogs with atlantoaxial instability.

BACKGROUND: Atlantoaxial instability (AAI) is primarily a congenital neurological disorder affecting young toy-breed dogs. So far, most studies have focused on bones and ligaments related to AAI, and there are no studies on the suboccipital muscles (SOMs) that occupy a large area from the occipital bone to C2 in dogs. This study evaluated the cross-sectional area (CSA) and fat infiltration of the SOMs using magnetic resonance imaging (MRI), specifically, T1-weighted images, in normal dogs (≤ 5 kg) and AAI dogs. The relationship between the severity of the neurological symptoms of AAI (group A and group B) and the values from MRI was also assessed. RESULTS: AAI dogs had significantly smaller CSA (P = 0.029) and greater fat infiltration (P = 0.044) of the SOMs compared to normal dogs. AAI dogs with mild neurological symptoms for a long period (group A) had greater fat infiltration than AAI dogs with severe neurological symptoms (group B) (P = 0.035). CONCLUSIONS: The muscle changes are most likely due to spinal cord compression resulting from instability; however, the possibility that chronic changes of the muscle may play an additional role in maintaining stability in this region cannot be excluded. This study provides fundamental quantitative information of the SOMs in normal and AAI dogs.

Biomechanical evaluation of two dorsal and two ventral stabilization techniques for atlantoaxial joint instability in toy-breed dogs.

OBJECTIVE: To compare the biomechanical properties of atlantoaxial joints (AAJs) in canine vertebral column specimens stabilized with 4 techniques (dorsal wire, modified dorsal clamp, ventral transarticular pin, and augmented ventral transarticular pin fixation) after transection of the AAJ ligaments. SAMPLE: 13 skull and cranial vertebral column segments from 13 cadaveric toy-breed dogs. PROCEDURES: Vertebral column segments from the middle aspect of the skull to C5 were harvested and prepared; AAJ ligament and joint capsule integrity was preserved. The atlantooccipital joint and C2 to C5 vertebral column segments were fixed with 2 transarticular Kirschner wires each. The occipital bone and caudalmost aspect of each specimen were embedded in polymethylmethacrylate. Range of motion of the AAJ under shear loading conditions up to 15 N was determined for each specimen during the third of 3 loading cycles with intact ligaments, after ligament transection, and after stabilization with each technique in random order. For each specimen, a load-to-failure test was performed with the fixation type tested last. RESULTS: All stabilization techniques except for dorsal clamp fixation were associated with significantly decreased AAJ range of motion, compared with results when ligaments were intact or transected. The AAJs with dorsal wire, ventral transarticular pin, and augmented ventral transarticular pin fixations had similar biomechanical properties. CONCLUSIONS AND CLINICAL RELEVANCE: Dorsal wire, ventral transarticular pin, and augmented ventral transarticular pin fixation increased rigidity, compared with results for AAJs with intact ligaments and for AAJs with experimentally created instability. Additional studies are needed to assess long-term stability of AAJs stabilized with these techniques.

Inverted V-shaped extracapsular stabilisation technique and arthroscopic findings in six dogs with medial shoulder instability.

OBJECTIVES: The aim of this case series was to report arthroscopic findings and to evaluate clinical outcomes of dogs treated with an inverted V-shaped extracapsular stabilisation technique without additional external coaptation for medial shoulder instability. MATERIAL AND METHODS: Medical records of dogs with medial shoulder instability that underwent arthroscopy and an inverted V-shaped extracapsular stabilisation technique were retrospectively reviewed. Extracapsular stabilisation was performed in all dogs using screws and spiked washers as anchor points for the coated polyester prosthetic ligament. No additional external coaptation was used in any dog. A minimum 18-month follow-up period was required for study inclusion. Complications and long-term outcomes were recorded. RESULTS: The subscapularis tendon and medial glenohumeral ligament were the structures most commonly affected. All dogs had pathological cartilage fibrillations. Implants were successfully placed in all dogs. Implant loosening was recorded in two out of six dogs on recheck but no revision surgery was performed. Function at the time of last clinical follow-up (median, 28 months, range 18 to 33 months) was full in four out of six and acceptable in two out of six dogs. CLINICAL SIGNIFICANCE: Surgical treatment of medial shoulder instability using the novel inverted V-shaped extracapsular stabilisation technique was successful. Potential complications such as implant loosening may occur. Despite the limited number of cases, the present study suggests that additional postoperative external coaptation may not be necessary for successful management of dogs with medial shoulder instability.

Comparison of classic and needle arthroscopy to diagnose canine medial shoulder instability: 31 cases.

This retrospective study compared surgery time, anesthesia time, and costs recorded with classic arthroscopy or needle arthroscopy when diagnosing canine medial shoulder instability. Signalment, examination findings, diagnostics, anesthesia time, surgery time, treatment, invoices, and complications were reported. All cases (classic arthroscopy, 14 cases; needle arthroscopy, 17 cases) were diagnosed with medial shoulder instability. Anesthesia times, surgery times, and invoices were statistically compared for classic and needle arthroscopy (P < 0.05). No significant differences were reported for surgery time (P = 0.13) but existed for anesthesia time (35 minutes shorter with needle arthroscopy; P < 0.0001) and invoice (38% lower with needle arthroscopy; P < 0.0001). No complications were recorded by the time of last direct follow-up, which was at a mean of 12.4 weeks after surgery. Needle arthroscopy offers an alternative, safe technique to reliably diagnose canine medial shoulder instability. Shorter anesthesia times and lower costs to the client may be advantages of needle over classic arthroscopy.

Comparaison de l'arthroscopie classique à l'arthroscopie l'aiguille pour diagnostiquer l'instabilité médiale de l'épaule chez le chien : 31 cas. Cette étude rétrospective a comparé le temps de chirurgie et d'anesthésie ainsi que les coûts engendrés entre une arthroscopie classique et une arthroscopie à l'aiguille lors du diagnostic de l'instabilité médiale de l'épaule chez le chien. Sont rapportés dans cette étude, les commémoratifs, les résultats de l'examen clinique, les diagnostics, le temps d'anesthésie, le temps de chirurgie, le traitement, les coûts et les complications. Le temps d'anesthésie et de chirurgie ainsi que leur coût ont été comparés pour les deux techniques arthroscopie classique et arthroscopie à l'aiguille (P < 0,05) pour tous les cas diagnostiqués avec une instabilité médiale de l'épaule (classique = 14; aiguille = 17). Aucune différence significative n'a été mise en évidence pour la durée de la chirurgie (P = 0,13) à contrario de la durée de l'anesthésie, plus courte (35 min de moins avec la technique à l'aiguille; P < 0,0001) et moins coûteuse (38 % plus économique avec la technique à l'aiguille; P < 0,0001). Aucune complication n'a été enregistrée lors de la dernière consultation de contrôle post-opératoire qui avait lieu en moyenne 12,4 semaines après la chirurgie. Pour diagnostiquer une instabilité médiale de l'épaule, la technique à l'aiguille offre une alternative sûre, avec comme avantages, des durées d'anesthésie plus courtes et des coûts inférieurs pour le client, par rapport à la technique classique.(Traduit par les auteurs).

Influence of the Head Neck Position on Imaging Measurements Used to Assess the Craniovertebral Junction in Small Breed Dogs: A Cadaveric Study.

OBJECTIVE: The study aimed to determine the influence of head neck position on imaging measurements used to assess the craniovertebral junction (CVJ) and to recommend the most appropriate position for the evaluation of the CVJ. STUDY DESIGN: A cross-sectional sample of adult dogs' cadavers was subjected to a computed tomography scan of the cranium and the cranial cervical region in three standardized head positions. Imaging measurements often used to assess the CVJ were measured. The influence of the head neck position, breed, weight and gender on imaging measurements was tested using repeated measures analysis of variance. RESULTS: Twenty-eight cadavers of small breed dogs were enrolled in the study. All cadavers examined had occipital dysplasia. All transarticular imaging measurements were dependent on the head neck position. In addition, the breed, weight and gender had an influence on several measurements. CONCLUSION: We recommend a standardized head neck position of 50 degrees flexion if quantitative imaging measurements of the CVJ are used to diagnose pathologies in this region. Future studies should focus on the definition of cut-off values for quantitative imaging measurements of the CVJ to differentiate between healthy and diseased small breed dogs. Regarding atlantoaxial instability, a combination of six parameters (C1-C2 angle, C1-C2 overlap, atlantoaxial distance, dens-to-axis length ratio, ventral compression index and clivus canal angle) is promising for its diagnosis.

Reconstruction of the cranial cruciate ligament using a semitendinosus autograft in a lapine model.

OBJECTIVE: To clarify and improve a cranial cruciate ligament (CrCL) deficient stifle stabilization technique using a semitendinosus tendon (ST) autograft fixed with an interference fit screw (IFS) in a closed-joint trauma lapine osteoarthritis (OA) model. STUDY DESIGN: Experimental OA model. ANIMALS: Forty-one Flemish Giant rabbits. METHODS: Following arthrotomy of traumatized lapine stifles, the ST insertion on the tibial plateau was exposed and the ST was transected near its origin. The graft was passed through tibial and femoral tunnels, manually tensioned and then secured in place with a custom IFS and periosteal sutures. Drawer was manually assessed during and immediately after surgery intraoperatively. Upon euthanasia, joint laxity was measured at 2, 10, or 22 weeks postoperatively and compared to that of the contralateral, intact stifles and stifles with a surgically transected CrCL. RESULTS: Minimal postoperative drawer was present in 34% of the rabbits and potentially correlated with meniscal injury and subsequent meniscectomy. CrCL reconstruction significantly reduced joint laxity to a level (3.6 ± 1.6 mm) similar to that (2.7 ± 0.8 mm) in contralateral intact stifles. CONCLUSION: Surgical replacement of a traumatically injured CrCL using a ST autograft fixed with an IFS replicated a common human surgical technique and effectively restored joint stability in the short, medium, and long terms of the study. CLINICAL SIGNIFICANCE: The study provides researchers a useful, clinically relevant, post-traumatic CrCL deficient rabbit model for the study of OA and investigations of interventions to mitigate or prevent long-term joint degeneration.