Current Advances in Mesenchymal Stem Cell Therapies Applied to Wounds and Skin, Eye, and Neuromuscular Diseases in Companion Animals.

Mesenchymal stem cells (MSCs) are considered a very promising alternative tool in cell therapies and regenerative medicine due to their ease of obtaining from various tissues and their ability to differentiate into different cell types. This manuscript provides a review of current knowledge on the use of MSC-based therapies as an alternative for certain common pathologies in dogs and cats where conventional treatments are ineffective. The aim of this review is to assist clinical veterinarians in making decisions about the suitability of each protocol from a clinical perspective, rather than focusing solely on research. MSC-based therapies have shown promising results in certain pathologies, such as spinal cord injuries, wounds, and skin and eye diseases. However, the effectiveness of these cell therapies can be influenced by a wide array of factors, leading to varying outcomes. Future research will focus on designing protocols and methodologies that allow more precise and effective MSC treatments for each case.

Canine Upper Digestive Tract 3D Model: Assessing Its Utility for Anatomy and Upper Endoscopy Learning.

A teaching strategy using 3D-printed models of the canine upper digestive tract (UDT) for anatomy demonstration and upper endoscopy instruction was evaluated. The canine UDT (esophagus-stomach-duodenum) was scanned and 3D-printed molds were manufactured using silicone casting. First-year students were introduced to these 3D models in practical sessions alongside real specimens. Simultaneously, fifth-year students were trained in endoscope handling and anatomical recognition using 3D specimens. Both groups completed an anonymous survey. Results showed that overall, first-year (n = 93) and fifth-year (n = 45) students agreed or strongly agreed that the 3D-printed model was effective for learning purposes. In summary, first-year students highlighted an improved understanding of size, volume, topography, and easier manipulation of the 3D model compared to fresh specimens. Fifth-year students were more enthusiastic, finding the 3D model valuable for spatial vision and clinical training. While both groups were against completely replacing the natural UDT with the 3D model, first-year students were more hesitant. These findings suggest that the 3D model of the canine UDT is an effective tool for hands-on training in clinical endoscopy and a valuable, albeit complementary, resource for teaching anatomy and topography.

A Bilateral Acetabular Physeal Fracture Treated with External Fixation in an Immature Cat.

This study aimed to assess the outcome of a bilateral acetabular physeal fracture treated with external fixation in an immature cat, a surgical technique not usually employed in immature patients. The fixator took 40 days, and it was removed after radiographic bone healing was achieved. No significant complications related to the technique were identified, and the outcome was classified as good based on the functional assessment and pain scales employed. The use of external fixation for stabilising acetabular fractures in immature cats should be considered a viable technical option, especially for minimally invasive stabilisation.

External Fixation for Fracture Stabilization of the Sacrum in 15 Dogs.

This study aimed to evaluate the feasibility, complications, and outcomes of external fixation (EF) for the treatment of sacral fractures in dogs, either as a primary fixation system or as a complementary technique. A total of 15 dogs with sacral fractures were surgically treated using different EF configurations, either as primary or secondary stabilization. The results were evaluated for the extent of fracture reduction, stability during treatment, complications, and bone healing. In most cases, the outcomes were excellent in terms of bone healing, neurological conditions, and pain assessment. The mean bone healing time was 9.45 ± 5.66 weeks. One (6.66%) patient presented a complication due to the technique. In conclusion, the use of EF should be considered for the stabilization of sacral fractures because of its minimal invasiveness, stability, and ease of application.

Retrospective Assessment of Thirty-Two Cases of Pelvic Fractures Stabilized by External Fixation in Dogs and Classification Proposal.

The goals of this study were to evaluate the outcomes of bone healing, patient comfort during the treatment, functional results, and complications in pelvic fractures treated with external fixation, as well as to propose a classification system for the applied external frames. A total of thirty-two canine patients with pelvic fractures of different origins were treated. To provide a better reference for the frames used, an alphanumeric classification system was developed, detailing the frame structure and the number and location of the pins used. In this study, eighty-six fractures were treated in the 32 patients of this work, with an average fixation time of 9.88 ± 4.15 weeks. No major complications were detected in this case cohort, and the outcomes were rated at 9.46 based on a visual assessment scale for the patient's comfort during treatment. Outcomes graded as excellent and good were 96%. The use of external fixation for stabilization of pelvic fractures should be considered as a technical option, especially for minimally invasive stabilization of complex fractures, either as a primary or secondary stabilization.

Orthotics and prosthetics by 3D-printing: Accelerating its fabrication flow.

Orthoses and socket prostheses are rarely used orthopaedic devices in veterinary medicine. Recently, more pet owners have sought these treatments for pets with orthopaedic conditions. However, veterinarians often lack substantial scientific evidence on device outcomes and may expect high costs, the main limiting factor, if human orthopaedic market prices are assumed. This discrepancy creates an imbalance between pet owners' expectations, veterinarians' recommendations, and actual patient benefits. To address economic constraints and enhance knowledge about these devices, this study used 3D technology-namely 3D scanning and printing via fused deposition modelling-to design, modify, and manufacture orthoses and socket prostheses for ten patients, including nine dogs and one calf. An equation was devised and applied to all printed devices to streamline the resizing process for sockets and orthoses. The 3D-printed devices were fitted to the patients, and their adaptation was assessed using three novel scales based on prior scientific literature in the small animal orthopaedic field. The orthoses were well-tolerated, with successful and straightforward adaptation. Although socket prostheses were tolerated, the dogs' adaptation was suboptimal, while the calf demonstrated excellent and immediate adaptation.

Short communication: Torsional tests on long-bone cylindrical medullary-canal exo-endoprostheses.

Torsion tests are performed for cylindrical type of a novel exo-endoprosthesis internal part. It is verified that it has values greater than those obtained for elliptical type. The best bonding method between PEEK and threaded rod is the resin adhesive, matching the obtained results for elliptical implant. Results of cylindrical type are discussed versus elliptical type.

Biomechanical Tests on Long-Bone Elliptical Medullary-Canal Endoprostheses for Limb Salvage in Dogs.

Exo-endoprosthesis is a limb salvage procedure poorly described for animals, as only expensive metal devices have been used so far. Currently, additive manufacturing (AM) can make this type of implant affordable by exploring a wide new range of materials. However, safety factors should be considered and could be related to kinetic and kinematic studies of canine natural gaits. The suitability of a novel inner part of an exo-endoprosthesis manufactured by fuse deposition modeling (FDM) was assessed for long canine bones with an elliptical medullary canal. Polyether ether ketone (PEEK) was the material used as an alternative to metal for veterinary traumatology. Poisson's ratio of 3D-printed PEEK material and ex vivo mechanical tests of the customized endoprosthesis were performed for the evaluation. The customized endoprostheses had promising outcomes for the radii of 20 kg dogs. Quasistatic mechanical tests of bone-inserted endoprostheses-pure compression tests-reached a maximum force of 1045.0 ± 78.0 N. In fatigue tests, the samples reached 500,000 cycles without failure or detriment to their quasistatic results. These outcomes surpass the natural weight-bearing of dogs, even during a galloping pace. Furthermore, torque tests with different adhesives were performed to obtain reference data for future assessments comparing with natural dog movements.

Biomechanical Test of a New Endoprosthesis for Cylindrical Medullary Canals in Dogs.

Exo-endoprosthesis is a limb salvage procedure for animals, although only expensive metal devices have been described. Now-a-days, new materials for this type of implant could be considered due to novel and affordable manufacturing techniques. However, a factor of safety (FoS) should be considered. There are kinetic and kinematic studies of canine natural gaits, which can be used to establish an FoS for mechanical tests for new non-metallic devices. Polyetheretherketone (PEEK) is used in different specialties in human medicine. Its mechanical properties (and its close mechanical stiffness to that of bone) make this polymer an alternative to metals in veterinary traumatology. PEEK could also be used in 3D printing. The suitability of a novel inner part of an exo-endoprosthesis manufactured by fuse deposition modeling (FDM) was presented in this study for long canine bones. Mechanical characterization of 3D-printed PEEK material and ex vivo mechanical tests of a customized endoprosthesis were performed to address it. Young's modulus of 3D-printed PEEK suffered a reduction of 30% in relation to bulk PEEK. Customized 3D-printed PEEK endoprostheses had promising outcomes for the tibiae of 20 kg dogs. Pure compression tests of the non-inserted endoprostheses showed a maximum force of 936 ± 199 N. In the bending tests of non-inserted endoprostheses, the PEEK part remained intact. Quasistatic mechanical tests of bone-inserted endoprostheses (compression-bending and pure compression tests) reached a maximum force of 785 ± 101 N and 1,642 ± 447 N, respectively. In fatigue tests, the samples reached 500,000 cycles without failure or detriment to their quasistatic results. These outcomes surpass the natural weight-bearing of dogs, even during a galloping pace. In conclusion, the 3D-printed PEEK part of the endoprosthesis for an exo-endoprosthesis can withstand loading, even during a galloping pace.

Short-term outcomes and complications of 65 cases of porous TTA with flange: a prospective clinical study in dogs.

BACKGROUND: Cranial cruciate ligament rupture (CrCLR) is the most common orthopaedic cause of lameness in the hind limb in dogs. Many surgical treatments have been described, but tibial tuberosity advancement (TTA) is one of the most commonly used today. Since it was first described, TTA has evolved to reduce major complications and to arrest the progression of osteoarthrosis. The aim of this study was to assess a surgical technique called Porous TTA with flange prospectively. This study was performed in 61 dogs that underwent 65 Porous TTA with flange procedures, to validate it as an alternative CrCLR treatment. Complications and clinical outcomes (pain, lameness, weight bearing, flexion, extension, crepitation and atrophy) were reported over 3 months, i.e. at 3, 6 and 12 weeks postoperatively. RESULTS: The results showed a positive clinical outcome, a minor complication rate of 47.69% at the first review 3 weeks postoperatively, 10.77% at the second one (6 weeks after the surgery) and 4% at the third one (at 12 weeks). Major complications were observed only at the last review, with one case that had an infection requiring implant removal; this represented 1.5% of cases. Variables evaluated for a relationship with complication scores and improvement were body condition score, sex, age, breed, body weight, breed size, side of the affected limb, traumatic anamnesis and time of lameness before surgery. No relationship was detected. CONCLUSIONS: Clinical outcomes and complications show that Porous TTA with flange is an efficient alternative for surgical treatment of CrCLR in dogs.

Facilitation of arthroscopic visualization and treatment of meniscal tears using a stifle joint distractor in the dog.

BACKGROUND: Stifle arthroscopy has been described to have high sensitivity and specificity in the evaluation of menisci in dogs, particularly for the medial meniscus. However, the visualization of menisci can be difficult. The use of femoral distractors in human medicine has been described to simplify demanding surgical procedures, such as meniscus transplantation. In veterinary medicine, stifle distraction has been reported to facilitate access to the joint and visualization of intra-articular structures, but there are no studies reporting the use of a stifle distraction technique while performing challenging surgical procedures, such as meniscal suture, in clinical patients. The objective of this study was to evaluate the feasibility, effectiveness and safety of stifle distraction to achieve consistent visualization of menisci and to facilitate performing arthroscopic procedures in clinical patients with stifle disease. Initial arthroscopic evaluation of the stifle joint was performed without distraction in the study population consisting of 13 dogs with naturally occurring stifle disease. The criteria for inclusion was prospectively set as the observation of a frank disease or anomaly of the menisci that could not be further treated or clarified without the risk of damaging the joint cartilage due to the requested manoeuvres. After the first examination, distraction was applied in order to complete the assessment of menisci. After achieving an accurate diagnosis, partial meniscectomy or meniscal repair was performed as needed while maintaining the distraction. RESULTS: Complete visualization and assessment of menisci were achieved thanks to the use of distraction. This manoeuvre facilitated access to the required area of the involved meniscus, and meniscal treatment could be successfully performed without damaging the articular cartilage. During the follow-up period, no postoperative complication related to the distraction or to the arthroscopic procedure was observed. CONCLUSIONS: Stifle joint distraction during arthroscopy in dogs improves visualization of both menisci, and particularly the caudal horn of the medial meniscus. Despite being a subjective assessment, it is the authors' opinion that this procedure also increases the ease of performing challenging procedures like meniscal suture, as it enlarges the space available to reach the correct working angulations.

Evaluation of sixty-eight cases of fracture stabilisation by external hybrid fixation and a proposal for hybrid construct classification.

BACKGROUND: Hybrid external fixation (HEF) is an emerging technique for fracture stabilization in veterinary orthopedics, but its use has been reported in few papers in the veterinary literature. The linear and circular elements that form hybrid fixators can be connected in a very high number of combinations, and for this reason just referring to HEF without any classification is often misleading about the actual frame structure. The aim of this study was to retrospectively evaluate fracture stabilization by HEF in 58 client-owned dogs and 8 cats, and to extend the already existing classification for hybrid constructs to include all frame configurations used in this study and potentially applicable in clinical settings. Animal signalment, fracture classification, surgical procedure and frame configuration were recorded. Complications, radiographic, functional and cosmetic results were evaluated at the time of fixator removal. RESULTS: Sixty-eight fractures in 58 dogs and eight cats were evaluated. Two dogs had bilateral fractures. Fifty-one percent were radio-ulna, 34% tibial, 9% humeral, 3% femoral and 3% scapular fractures. One ring combined with one or two linear elements was the most widely employed configuration in this case series. Radiographic results at the time of frame removal were excellent in 59% of the cases, good in 38% and fair in 3%, while functional and cosmetic results were excellent in 69% of the cases, good in 27% and fair in 4%. CONCLUSIONS: HEF is a useful option for fracture treatment in dogs and cats, particularly for peri and juxta-articular fractures. It can be applied with a minimally invasive approach, allows adjustments during the postoperative period and is a versatile system because of the large variety of combinations that can fit with the specific fracture features. The classification used enables to determine the number of linear and circular elements used in the frame.