Combined cholecystotomy, retrograde hydropulsion, and choledochal stenting to treat extrahepatic biliary tract obstruction in 3 cats.

Extrahepatic biliary tract obstruction (EHBO) is uncommonly encountered in cats. Surgical treatment aims to decompress the biliary tract and insure bile duct patency. In veterinary medicine, cholecystotomy is not widely used in practice. The objective was to describe the use of cholecystotomy, retrograde hydropulsion of choleliths, and choledochal stenting to remove choleliths from the extrahepatic biliary tract back in the gallbladder. Three adult domestic shorthair cats were presented with anorexia, lethargy, and vomiting. Serum biochemistry revealed hyperbilirubinemia and increased hepatic enzymes. Abdominal ultrasonography showed evidence of EHBO requiring surgical intervention. Choleliths were localized in the proximal and middle portions of the common bile duct (CBD) in the first case, in the distal portion of the CBD and within the major duodenal papilla in the second case, and in the middle and distal portions of the CBD in the third case. Cholecystotomy was followed by retrograde hydropulsion of the choleliths into the gallbladder, after which choledochal stenting was performed. Complications were defined as major when requiring additional medical or surgical treatment, or minor when not. Three major complications were reported. In 2 cases, severe anemia requiring blood transfusion occurred 24 h postoperatively; in 1 case, EHBO recurrence was encountered 41 d postoperatively. All cats were discharged within 4 d following surgery. Two cats were still alive at 12 and 14 mo after surgery, respectively. In the last case, owners refused revision surgery and the cat was euthanized. Key clinical message: Cholecystotomy combined with retrograde hydropulsion of choleliths permitted removal of choleliths and decompression of the biliary tract in 3 cats. Major complications included severe anemia and EHBO recurrence.

Cholécystotomie combinée, hydropulsion rétrograde et pose de stent cholédocien pour traiter l'obstruction des voies biliaires extra-hépatiques chez 3 chats. Les obstructions biliaires extra-hépatiques (OBEH) sont peu fréquentes chez le chat. Le traitement chirurgical vise à lever l'obstruction et s'assurer de la perméabilité des voies biliaires. En médecine vétérinaire, la cholécystotomie est une technique peu pratiquée. L'objectif de ce rapport de cas était de décrire l'utilisation de la cholécystotomie, de l'hydropulsion rétrograde des cholélithes et d'une prothèse endoluminale cholédoquale (PEC) pour repousser les cholélithes présents dans les voies biliaires extrahépatiques dans la vésicule biliaire (VB).Trois chats européens adultes ont été présentés pour anorexie, léthargie et vomissements. La biochimie sérique a révélé une hyperbilirubinémie et une augmentation des enzymes hépatiques. L'échographie abdominale a mis en évidence une OBEH nécessitant une intervention chirurgicale. Les cholélithes étaient situés dans la portion proximale et moyenne du canal cholédoque pour le premier cas; dans la portion distale et la papille duodénale majeure dans le second cas; dans la portion moyenne et distale pour le troisième cas. Une cholécystotomie a été suivie d'une rétro-hydropulsion des cholélithes dans la VB, puis une PEC a été placée. Les complications ont été définies comme majeures lorsqu'elles nécessitaient un traitement médical ou chirurgical supplémentaire, ou mineures lorsqu'elles n'en nécessitaient pas.Trois complications majeures ont été rapportées : chez 2 cas, une anémie sévère a été observée 24 h après l'intervention, nécessitant une transfusion sanguine; chez un cas, une récidive d'obstruction biliaire a eu lieu à 41 jours postopératoire. Tous les patients sont sortis de l'hôpital dans les 4 jours suivant l'opération. Deux cas étaient encore en vie 12 et 14 mois après l'intervention. Pour le dernier cas, la seconde chirurgie a été refusée par les propriétaires et le chat a été euthanasié.Message clinique clé :La cholécystotomie combinée à l'hydropulsion rétrograde des cholélithes a permis le retrait de cholélithes obstructives (dont certaines distales) et la décompression du tractus biliaire chez 3 chats. Les complications majeures incluaient une anémie sévère et une récidive d'obstruction biliaire.(Traduit par les auteurs).

Prevalence of elbow dysplasia in 13 dog breeds in France: a retrospective radiographic study (2002-2022).

OBJECTIVE: To describe the prevalence of elbow dysplasia (ED) in 13 dog breeds in France. ANIMALS: A total of 18,870 elbow radiographs taken from 2002 to 2022 were evaluated by 2 independent examiners. METHODS: For each breed, the incidence of each of the 4 International Elbow Working Group scoring classes was extracted from the database. Breeds were excluded if fewer than 150 radiographs had been read for that breed. RESULTS: This study included 17,861 records for 13 dog breeds: American Akita, Alaskan Malamute, Old German Shepherd (Altdeutscher Schäferhund), American Staffordshire Terrier, Australian Shepherd, Belgian Shepherd, White Swiss Shepherd, Bernese Mountain Dog, Cane Corso, Czechoslovakian Wolfdog, Rhodesian Ridgeback, Rottweiler, and Dogue de Bordeaux. The overall prevalence of ED was 11.4%, ranging from 1.1% in the Czechoslovakian Wolfdog to 32.2% in the Dogue de Bordeaux. The Dogue de Bordeaux, Rottweiler, Bernese Mountain Dog, and Cane Corso breeds were most commonly affected by ED. The prevalence of ED was significantly higher in male dogs than in female dogs (17.5% vs 10.5%, P < .05). Joint incongruity and fragmented coronoid process were the 2 most common primary ED lesions identified. The prevalence of ED among the dogs evaluated decreased over the timeframe of the study. CLINICAL RELEVANCE: The results of this study help to clarify the prevalence of ED in different breeds in France. These data should be interpreted with caution as this study included a small percentage of the total number of dogs born for each breed in France over the study period.

Retrospective study of the early clinical experience with a precontoured angle-stable interlocking nail for fracture repair in dogs and cats.

OBJECTIVE: To report indications, outcomes, and complications with a precontoured angle-stable interlocking nail (CAS-ILN). ANIMALS: 90 client-owned animals. METHODS: Dogs and cats treated with the CAS-ILN between 2020 and 2022 were retrospectively reviewed. Collected data included body weight, fracture configuration, percentage of medullary canal filled, limb alignment, complications, and follow-up. Favorable outcomes were defined when full functional restoration was observed. RESULTS: Thirty-eight dogs and 52 cats were included. Median body weight was 4.3 kg (range, 1.5 to 6.7 kg) for cats and 25 kg (range, 6.8 to 54 kg) for dogs. A total of 54 femurs, 31 tibias, and 5 humeri were treated, including 65 comminuted fractures and 26 metaphyseal fractures. The median percentage of medullary canal occupied by the nail was 76.5% (range, 53% to 97.6%). Radiographic postoperative bone alignment was good in 85.5% (59/69) and satisfactory in 10 cases. The median duration of follow-up (57/90) was 476 days (range, 56 to 1,057 days). In the perioperative period (0 to 12 weeks), lameness had resolved or was mild in all (51/52) but 1 case. In the long-term postoperative period (> 12 months), 97.1% (34/35) of cases showed restoration of full function and 1 case had an unacceptable function. An overall complication rate of 11.5% (7/61) was reported including 1 catastrophic and 6 major complications. CLINICAL RELEVANCE: Long-term functional outcomes following the CAS-ILN were favorable in 97.1% (34/35) of cases. Complication rates were comparable to previous studies. The CAS-ILN appears to be an alternative surgical option for most long-bone fracture repairs.

Incidentally detected retroperitoneal paraganglioma in a 10-year-old French bulldog.

This article reports a case of a 10-year-old French bulldog initially seen for reluctance to move and episodes of pain. A magnetic resonance imaging study was undertaken in order to rule out a herniated disc. A large, retroperitoneal mass was visualized and cytological analysis suggested a neoplastic proliferation. The mass appeared to compress the caudal vena cava when viewed by abdominal CT scan. The mass was surgically removed. A nephrectomy was also carried out and aortic bleeding identified after dissection of adhesions. Despite these complications, the dog did well after the procedures. Postoperative checkups were normal. Histological and immunohistochemical analyses of the mass were compatible with a retroperitoneal paraganglioma. Key clinical message: This type of tumor is poorly described in the veterinary literature. As the behavior of this tumor type is not yet fully understood, each new description adds to our knowledge and should help in diagnosing and treating it more effectively in the future.

Paragangliome rétropéritonéal de découverte fortuite chez un bouledogue Français de 10 ans. Cet article expose le cas d'un chien mâle entier bouledogue Français de 10 ans présenté initialement pour des difficultés locomotrices et des manifestations algiques. Un examen d'imagerie par résonnance magnétique (IRM) est rapidement réalisé afin d'explorer l'hypothèse d'une hernie discale. Une volumineuse masse rétropéritonéale est alors mise en évidence. L'analyse cytologique de cette dernière est compatible avec un processus néoplasique. Après la réalisation d'un examen par tomodensitométrie de l'abdomen et la mise en évidence d'une compression marquée de la veine cave caudale par la masse, une prise en charge chirurgicale avec exérèse de la masse est décidée. Lors de l'intervention chirurgicale une néphrectomie est réalisée et un saignement aortique est identifié après la dissection des adhérences. Malgré ces complications, le chien se réveille bien et les contrôles post opératoires effectués sont satisfaisants. Les analyses histologiques et immunohistochimiques de la masse seront en faveur d'un paragangliome rétropéritonéal extra surrénalien.Message clinique clé :Ce type tumoral fait l'objet de peu de descriptions dans la littérature vétérinaire. Toute la lumière n'a pas encore été faite sur son comportement et chaque nouvelle description permet d'en enrichir les connaissances et donc de mieux comprendre ce type tumoral, ce qui, à l'avenir, pourra aider à le diagnostiquer plus facilement et à le traiter plus efficacement.(Traduit par les auteurs).

COAST Development Group's international consensus guidelines for the treatment of canine osteoarthritis.

This report describes consensus guidelines and recommendations for the treatment of canine osteoarthritis (OA) according to the "Canine OsteoArthritis Staging Tool excluding radiography" (COASTeR) stage of OA, by the COAST Development Group. The recommendations are based on evidence-based medicine and clinical experience and are proposed with international relevance in mind. The aim is to provide veterinarians with a practical reference to consolidated information and to support the development of patient-specific OA management protocols and informed treatment choices based on the stage of OA.

Intra-articular replacement of the caudal cruciate ligament using a UHMWPE ligament under arthroscopic guidance in a dog: A case report.

Background: As isolated ruptures of the caudal cruciate ligament (CdCL) are rare in dogs, there is no consensus on the indications and the gold-standard surgical technique for treatment. Case Description: A 2-year-old Shepherd dog with an isolated rupture of the CdCL was treated with a new surgical technique for synthetic reconstruction. Three bone tunnels were drilled in the femur and the tibia under arthroscopic guidance to make sure the anatomical insertions of the physiological ligament were respected. An ultra-high molecular weight polyethylene (UHMWPE) implant was fixed with interference screws to reconstruct the CdCL. A synovial inflammation remained present on radiographs for 6 months after the surgery, together with a mild lameness. However, the dog fully recovered clinically and recovered a normal level of activity after 6 months. Liverpool osteoarthritis in dogs questionnaire results at 6 months and 1 year postoperatively were excellent. Conclusion: The use of a UHMWPE implant fixed with interference screws to reconstruct the CdCL allowed a return to full function of the knee without complications, despite a persistent synovial inflammation and mild lameness for a 6-month period after the surgery. The success of this isolated surgical technique could lead to improvements in the surgical management of CdCL rupture, if these initial results are confirmed by a prospective study with a larger number of patients.

Concurrent bucket handle meniscal tear treated with arthroscopic partial meniscectomy does not influence midterm outcomes after tibial plateau leveling osteotomy.

OBJECTIVE: To assess the effect of arthroscopic partial meniscectomy in dogs with bucket handle meniscal tears and tibial plateau leveling osteotomy (TPLO), compared with dogs with cranial cruciate ligament rupture and no meniscal tear treated by TPLO alone. ANIMALS: 30 client-owned dogs with cranial cruciate rupture treated by either TPLO and arthroscopy alone if the meniscus was normal (normal meniscus [NM] group, n = 14) or by TPLO and an arthroscopic partial meniscectomy if a bucket handle tear was diagnosed (meniscal tear [MT] group, n = 16). METHODS: Medical records, lameness score, and symmetry gait analysis parameters were retrospectively collected from patient records preoperatively (PreO), then at 1, 3, and 6 months postoperatively (M1, M3, and M6, respectively). Osteoarthritic (OA) radiographic score was performed and compared at PreO and M6. RESULTS: PreO gait analysis parameters were lower in the MT group (P < 0.005). In the MT group, the lameness score significantly improved between PreO and M1, and there were no significant differences between groups at M6. OA score was significantly higher in the MT group at PreO and M6. However, postoperative progression of OA did not differ between the 2 groups (P = 0.16). CLINICAL RELEVANCE: Treatment for meniscal tear results in a significant improvement in lameness, with postoperative outcomes at 6 months comparable with dogs with intact menisci. Despite having significant osteoarthritic lesions at all time points, the progression of osteoarthritis is similar between dogs with meniscal tears and those with intact menisci.

Ex-vivo biomechanical analysis of an original repair of canine calcaneal tendon rupture using a synthetic implant as mechanical support fixed by sutures in the proximal tendinous part and by an interference screw in the bone distal part.

Background: Rupture of the common calcaneal tendon is the second most frequent tendon rupture in dogs and may lead to severe lameness and pain. Surgical repair consists of re-apposition of the damaged tendon ends using sutures, but this type of repair is not always possible especially if the tendon has retracted. Tendon augmentation with an ultra-high molecular weight polyethylene (UHMWPE) implant is a recent solution to support the sutures and allow the repair of the canine calcaneal tendon. However, its biomechanical fixation strength remains untested for this pathology. Aim: To evaluate the biomechanical fixation strength of a UHMWPE implant for the repair of the canine calcaneal tendon. Methods: Ex-vivo biomechanical study was carried out on eight cadaveric hindlimbs from four adult dogs. Hindlimbs were tested under two independent modalities: proximal tendinous fixation (PTF) and distal calcaneus fixation (DCF), using a testing machine. PTF was achieved by eight simple interrupted polypropylene sutures performed through the UHMWPE implant. The latter was sandwiched inside the gastrocnemius tendon, which had previously been incised over about 5 cm longitudinally, and through the tendon of the superficial digital flexor. DCF was performed using an interference screw, which locked the UHMWPE implant into a calcaneus tunnel drilled perpendicularly. Results: Yield, failure load, and linear stiffness (mean ± SD) for the DCF modality were 920 ± 139 N, 1,007 ± 146 N, and 92 ± 15.21, respectively, which were greater than for the PTF modality (663 ± 92 N, 685 ± 84 N and 25.71 ± 5.74, respectively, p < 0.05). Failure modes were different between fixation modalities: for PTF it was suture breakage (n = 7/8), while for DCF it was implant damage and slippage (n = 8/8). Conclusion: The biomechanical fixation strength of the UHMWPE implant was greater for DCF than that of PTF, and should be suitable for calcaneal tendon repair in dogs. The clinical prediction of rupture of this calcaneal tendon repair will occur at the level of the PTF.

Effect of the surface geometry of uncemented acetabular cups on primary stability in a model of uncemented total hip replacement in dogs.

OBJECTIVE: To compare the in vitro stability of acetabular cups with peripherally reinforced fixation in a model of uncemented total hip replacement in dogs. SAMPLE: 63 polyurethane foam blocks and 3 acetabular implant designs: hemiellipsoidal (Model A) and 2 models with equatorial peripheral fins (Model B with 1 level and Model C with 2 levels of fins). METHODS: 2 loading patterns-edge loading and push-out tests-were performed until failure and peak forces were recorded. Implantation behavior was visually assessed and the required seating force was assessed using a force-displacement curve. RESULTS: Model B showed significantly lower peak force than Model A in edge loading tests with standardized impaction. In the push-out test, Model A had a greater maximal force than Models B and C, with mean maximal forces of 213.7 N, 139.4 N, and 138.9 N, respectively. In the seating force test, Models B and C required a higher force for 2-mm deep implantation (362.0 N and 361.6 N, respectively) than Model A (194.4 N), and were associated with dorsal tilting of the components. CLINICAL RELEVANCE: Our results suggest that cups with a peripheral design (B, C) have less primary stability than hemiellipsoidal cups (A). Furthermore, models with peripheral fins (B, C) appeared to have incomplete seating if a higher force was not used during implantation and, therefore, the risk of malpositioning was increased. These data indicate that hemiellipsoidal cups provide the same or better initial stability and require a lower impaction force.

Use of Ultrasonography in Diagnosis of Medial Compartment Disease of the Elbow in Dogs.

OBJECTIVE: The objective of this prospective study was to evaluate the use of ultrasonography in the diagnosis of medial coronoid process disease in unclear cases. STUDY DESIGN: Fifteen elbows (on thirteen dogs) for which radiography and computed tomography did not lead to a clear diagnosis of medial coronoid process disease were included. On each elbow, ultrasonography was performed with a high frequency linear transducer (12-18Hz). Then, arthroscopic examination of the joint was performed by a surgeon who was unaware of ultrasonographic findings to confirm medial coronoid process disease. RESULTS: At least one ultrasonographic lesion was detected in 13 out of 15 elbows. The main reported ultrasonographic lesions were joint effusion (10/15 elbows) and an abnormal shape of the medial coronoid process (irregular, ill-defined or fragmented) (9/15). CONCLUSION: Ultrasonography can be a helpful additional diagnostic tool to confirm medial coronoid process disease of the elbow joint before performing arthroscopy in unclear cases. Further studies will be needed to evaluate the use of higher frequency transducers and determine if it could improve the diagnostic value of ultrasonography.

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.

Validation of a biomechanical testing protocol of craniodorsal hip luxation in feline cadavers and comparison of two ultra-high molecular weight polyethylene materials used for extra-articular hip stabilisation.

OBJECTIVES: The aim of our study was to describe a biomechanical testing protocol to reproduce ex vivo craniodorsal hip luxation specific to the feline model, and evaluate the biomechanical properties of an intact hip joint compared with the fixation strength of two different techniques of extra-articular hip stabilisation. METHODS: Eighteen hip joints (femur and hemipelvis) were harvested from nine mature feline cadavers. CT was performed for each hip joint so that a biomechanical base specific to each joint morphotype could be created using computer-aided design. The biomechanical bases were then produced using a three-dimensional printer to secure the hip joints during testing. A total of 34 biomechanical compression tests were performed. Eighteen compression tests were performed in the control group, of which two fractured. The remaining 16 hip joints were then randomly assigned either to group A (hip joints stabilised with an extra-articular ultra-high molecular weight polyethylene (UHMWPE) implant secured by an interference screw [n = 8]) or to group B (hip joints stabilised with a UHMWPE iliofemoral suture [n = 8]). RESULTS: Mean ± SD yield, failure load and linear stiffness in the control group were 616 ± 168 N, 666 ± 158 N and 231 ± 50 N/mm, respectively. The relative fixation strength (% of intact joint) before hip luxation in groups A and B was 43.8% and 34.7%, respectively. No statistical difference was found between groups A and B for yield and failure load. However, the reoccurrence of craniodorsal hip luxation was higher in group B than in group A, in 5/8 and 0/8 tests, respectively. Moreover, in group A, the extra-articular UHMWPE implant induced caudodorsal hip luxation, reported as failure mode in 7/8 cases. CONCLUSIONS AND RELEVANCE: This modified biomechanical protocol for testing craniodorsal hip luxation in a feline model was validated as repeatable and with acceptable variance. The extra-articular UHMWPE implant stabilisation technique proved to be more efficient in avoiding reoccurrence of craniodorsal hip luxation than UHMWPE iliofemoral suture.

Ex vivo postimplantation biomechanical properties of a press-fit cementless femoral stem with transfixation pin for canine total hip replacement.

OBJECTIVE: To compare ex vivo postimplantation biomechanical characteristics of 3 implants for canine total hip replacement: a cementless press-fit femoral stem with a pin in the femoral neck (p-pfFS), a press-fit cementless femoral stem without this pin (pfFS), and a cemented femoral stem (cFS). SAMPLE: 18 cadaveric femurs from 9 dogs. PROCEDURES: Femurs were assigned randomly to 3 groups, and biomechanical testing was performed by measuring vertical displacement during cyclic loading and resistance to failure with compression parallel to the longitudinal axis of the femur. Force-displacement curves were assessed for failure tests, and work necessary for failure was calculated. RESULTS: No significant differences were observed in vertical displacement during cyclic loading (P = .263) or work necessary for failure (P = .079). Loads to failure for cFS and p-pfFS implants were significantly greater than that for the pfFS, but no significant difference in load to failure was observed between cFS and p-pfFS implants (P = .48). CLINICAL RELEVANCE: Cementless femoral stems with a transfixation pin offer significantly greater immediate resistance to failure to compressive loads parallel to the longitudinal axis of the femur than standard cementless stems, and a level of stability comparable to that of cemented stems. p-pfFS implants may be valuable in total hip replacement, potentially reducing the risk of fracture during the early postoperative period prior to osteointegration.

Long-term outcome following synthetical reconstruction of the medial collateral tarsal ligament in a dog.

Background: Tibiotarsal instabilities caused by partial or complete rupture of the medial collateral tarsal ligament (MCTL) are commonly treated by arthrodesis techniques with poor functional results and significant complication rates. Case Description: This study describes a new surgical technique for synthetic reconstruction of the MCTL in an overweight dog (estimated body condition score 8/9) with an avulsion of the long head of the MCTL. Three bone tunnels were drilled in the distal tibia, the talus, and the central tarsal bone, thus respecting the anatomical insertions of the physiological ligament. An Ultra-High Molecular Weight Polyethylene (UHMWPE) implant was fixed with interference screws to reconstruct the long and short heads of the MCTL. Premature weight-bearing was reported at 2 weeks postoperatively following early removal of the flexible restraint (bivalve resin boot), which had initially been prescribed for 6 weeks. At 11 weeks postoperatively, the tibiotarsal joint showed good valgus stability and the dog's gait was subnormal. At 12 and 16 months postoperatively, the dog regained full function of the operated limb although no weight loss was initiated as recommended. Conclusion: The use of a UHMWPE implant fixed with interference screws to reconstruct the MCTL allowed a return to full function of the tibiotarsal joint, without complications despite an early return to weight-bearing without external restraint. The success of this isolated surgical technique could lead to improvements in the surgical management of MCTL rupture if these initial results are confirmed by a prospective study with a larger number of patients.

Biomechanical cyclic loading test of a synthetic ligament fixation system used for intra-articular stabilization of deficient canine stifles.

Background: Cranial cruciate ligament rupture (CCLr) is the most common cause of hind limb lameness in dogs. Currently, surgical management of CCLr is mostly performed using tibial osteotomy techniques to modify the biomechanical conformation of the affected stifle. These surgical techniques have a significant complication rate, associated with persistent instability of the stifle which may lead to chronic postoperative pain. Over the last decade, studies have been published on various techniques of anatomical caudal cruciate ligament reconstruction in veterinary practice, using physiological autografts or woven synthetic implants. Aim: The aim of this ex vivo biomechanical study is to investigate the ex vivo dynamic biomechanical behavior of a synthetic implant [ultrahigh molecular weight polyethylene (UHMWPE) implant] fixed with interference screws for the treatment of CCLr in dogs, according to a fatigue protocol (48 hours per test). Methods: Seven stifles from four skeletally mature canine cadavers were implanted with the synthetic implant. It was fixed with four interference screws inserted in transversal and oblique tunnels in both the distal femur and the proximal tibia. For each case, 100,000 cycles were performed at 0.58 Hz, with traction loads ranging from 100 to 210 N. Results: Neither screw-bone assembly rupture nor a pull-out issue was observed during the dynamic tests. Linear stiffness of the implants associated with a fixation system with four interference screws increased over time. The final displacement did not exceed 3 mm for five of the seven specimens. Five of the seven synthetic implants yielded to a lengthening in functional range (0-3 mm). Linear stiffness was homogeneous among samples, showing a strong dynamic strength of the interference screw-based fixations of the UHMWPE implant in the femoral and tibial bones. Conclusion: This study completes the existing literature on the biomechanical evaluation of passive stifle stabilization techniques with a testing protocol focused on cyclic loading at a given force level instead of driven by displacement. These biomechanical results should revive interest in intra-articular reconstruction after rupture of the CCLr in dogs.

Mechanical evaluation of a novel angle-stable interlocking nail in a gap fracture model.

OBJECTIVE: To describe the mechanical characteristics of a novel angle-stable interlocking nail (NAS-ILN) and compare them to those of a locking compression plate (LCP) by using a gap-fracture model. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Synthetic bone models. METHODS: Synthetic bone models simulating a 50 mm diaphyseal comminuted canine tibial fracture were treated with either a novel angle-stable interlocking nail (NAS-ILN) or a locking compression plate (LCP). Maximal axial deformation and load to failure in compression and 4-point bending, as well as maximal angular deformation, slack, and torque to failure in torsion, were statistically compared (P < .05). RESULTS: In compression, the maximal axial deformation was lower for NAS-ILN (0.11 mm ± 0.03) than for LCP (1.10 mm ± 0.22) (P < .0001). The ultimate load to failure was higher for NAS-ILN (803.58 N ± 29.52) than for LCP (328.40 N ± 11.01) (P < .0001). In torsion, the maximal angular deformation did not differ between NAS-ILN (22.79° ± 1.48) and LCP (24.36° ± 1.45) (P = .09). The ultimate torque to failure was higher for NAS-ILN (22.45 Nm ± 0.24) than for LCP (19.10 Nm ± 1.36) (P = .001). No slack was observed with NAS-ILN. In 4-point bending, the maximal axial deformation was lower for NAS-ILN (3.19 mm ± 0.49) than for LCP (4.17 mm ± 0.34) (P = .003). The ultimate bending moment was higher for NAS-ILN (25.73 Nm, IQR [23.54-26.86] Nm) than for LCP (16.29 Nm, IQR [15.66-16.47] Nm) (P = .002). CONCLUSION: The NAS-ILN showed greater stiffness in compression and 4-point bending, and a greater resistance to failure in compression, torsion, and 4-point bending, than LCP. CLINICAL IMPACT: Based on these results, NAS-ILNs could be considered as alternative implants for the stabilization of comminuted fractures.

Micromechanical properties of the healthy canine medial meniscus.

AIMS: Knowledge of the micromechanical characteristics of the menisci is required to better understand their role within the stifle joint, improve early diagnosis of meniscal lesions, and develop new treatment and/or replacement strategies. The aim of the study was to determine the mechanical properties of the healthy medial canine meniscus and to evaluate the effect of regional (caudal, central, and cranial) and circumference (axial and abaxial) locations on these properties. METHODS: To study the micromechanical properties of the medial menisci in healthy (Beagle) dogs, the influence of regional (caudal, central, and cranial) and circumference (axial and abaxial) locations were evaluated. Nanoindentation-relaxation tests were performed to characterize the local stiffness and the viscoelastic properties at each region and specific circumference. Linear interpolation onto the indentation points was performed to establish a map of the micromechanical property heterogeneities. RESULTS: The results indicate that the cranial region was significantly stiffer and less viscous than the central and caudal regions. Within the central region the inner part (axial) was significantly stiffer than the periphery (abaxial). Within the caudal region the inner part was significantly less viscous than the periphery. CONCLUSION: Significant regional and radial variations were observed for both the stiffness and the viscoelastic properties. Moreover, a viscous behavior of the entire medial meniscus was observed (elastic fraction <0.5). These results deter the use of average elastic modulus to study the regional mechanical properties of healthy meniscus.

A morphometric analysis of thoracolumbar vertebrae in goat by computed tomography.

The goat spine is widely used as an animal model for preclinical research in human medicine to test new spinal implants and surgical procedures. Therefore, precise morphometric data are needed. This study aims to provide morphometric data of the goat thoracolumbar vertebrae and to define the parameters/characteristics of the optimum implantation corridors for pedicle screws in the thoracolumbar spine in goat. Eleven 36-month-old adult alpine goats were included in this study, and a sample of 198 vertebrae was measured. Subsequently, transverse and sagittal images were obtained using a multi-detector-row helical computed tomography (CT) scanner. Measurements of the vertebral bodies (ventral body width VBW, ventral body depth VBD, ventral body height ventral VBHv, ventral body high dorsal VBHd, spinal canal depth SCD, spinal canal width SCW), pedicles (pedicle length PDL, pedicle width PDW, pedicle angle PA and pedicle axis length PAL), intervertebral disc (DT) and transverse process length (TPL) were performed with dedicated software. The vertebral bodies and the spinal canal were wider than deep, mostly evident in the lumbar region. The intervertebral discs were as much as 65.7% thicker in the lumbar spine than in the thoracic spine. The pedicles were longer than wide over the thoracic and lumbar spines. The insertion angles in pedicle were approximately 30° for the T2-T4 segment, 25° for the T5-T6 segment, 23° for the T6 to T11 segment, 20° for T11 to L3, 25° for L4 and 30° for L5 and L6. In conclusion, the generated data can serve as a CT reference for the caprine thoracolumbar spine and may be helpful in using the goat spine as an animal model for human spinal research.

Anatomical features of the canine C2-C3 spinal cord vascular environment.

OBJECTIVE: Interarcuate branch (IAB) is a vascular structure, particularly developed in C2-3 intervertebral space, forming a dorsal bridge that connects ventral venous plexi in the vertebral canal. While precisely described in the human, the precise anatomical features of IABs have not been reported in the veterinary literature. The purpose of this study is to describe the features and relations of IABs in the C2-3 vertebral canal. ANIMALS: 10 dogs were enrolled; 5 dogs for necropsy and 5 dogs for histology. PROCEDURES: The ventral venous plexi in the cervical spine of 5 dogs were injected with latex and underwent vertebral canal dissection for visual assessment of the IAB. Two out of 5 dogs were injected with the addition of barium sulfate and underwent a CT scan. The C2-3 regions of 5 small-breed dogs were harvested for histological examinations. RESULTS: IABs arose from the ventral venous plexus at the level of the intervertebral vein; they originated from 2 separate branches located caudally and cranially to the intervertebral foramen, forming a ventrodorsal triangle surrounding the spinal nerve root. No dorsal anastomosis was observed on the CT scan nor at dissection but were observed histologically. A cervical fibrous sheath was observed all around the vertebral canal. CLINICAL RELEVANCE: IABs are voluminous venous structures at the C2-3 intervertebral space in dogs and found within a split of the cervical fibrous sheath, which is adherent to the interarcuate ligament and the ligamentum flavum. This anatomical description is paramount when planning an approach to the C2-3 intervertebral space.