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Gray horses spontaneously develop metastatic melanomas that resemble human disease, and this is often accompanied with metastasis to other organs. Unlike in other species, the establishment of primary equine melanoma cultures that could be used to develop new therapeutic approaches has remained a major challenge. The purpose of the study was to develop a protocol for routine isolation and cultivation of primary equine melanocytes. Melanoma tissues were excised from 13 horses under local anesthesia, mainly from the perianal area. The melanoma cells were isolated from the melanoma tissue by serial enzymatic digestion using dispase and collagenase. Out of the 13 excised melanomas, cell cultures from eight melanomas were established, which corresponded to a success rate 62%. These cells showed different degrees of melanin pigmentation. Characterization of these cells using confocal microscopy, FACs analysis and western blotting showed that they expressed melanoma-associated antigens; Melan-A, MAGE-1, and MAGE-3, and PCNA expression was higher in fast-proliferating isolates. The protocol we developed and established proved successful for routine isolation and cultivation of primary equine melanoma cells. This method provided a large number of primary equine melanoma cells that could be used to study new therapeutic approaches for treatment of equine melanomas

The In vitro experimental study on five cadaveric equine limb pairs (n=10) was conducted to evaluate the functionality and precision of the VetGate Computer Assisted Surgery (CAS) system during insertion of two 4.5mm cortex screws across virtual midsagittal fractures of the distal phalanx (P3) in the horse and to compare the results with those achieved with the SurgiGate 1.0 CAS-System in a similar study. In each specimen wo 4.5mm cortex screws were inserted computer assisted in lag fashion facilitated by the VetGate CASSystem. In none of the specimens did screw penetration of the articular- or solar surface or the semilunar canal, occur. The difference between optimal and actual screw length is significantly better in this study compared to a similar study conducted with the SurgiGATE 1.0 CAS-System. The results achieved with the VetGate CAS-System are even more precise than with the SurgiGATE 1.0 CAS-System (p<0.001). The VetGate CAS-System allows exact screw placement at delicate locations.

The incidence of fractures after a kick, coupled with marked soft tissue trauma at the site of injury, suggests that the force of a kick from the hind limb of a horse is enormous. The goal of this study was to measure this force and to investigate whether the Tekscan F-SCAN in-shoe pressure measuring system is suitable for quantification of the impact strength of a kick from a horse. The system was tested in 6 horses that had undergone clinical examination and gait analysis. The sensor-shoe combination was attached to each hind foot and the horse was stimulated to kick against a wall. The F-SCAN system measured the maximum vertical and horizontal force (N), the main contact area (cm2) of the sole with the floor (stance phase limb) or wall (kicking limb) and the duration (sec) that the sole was in contact with the floor or wall. In addition, each kicking event was recorded with a video camera for subjective evaluation. The mean kicking force measured was lower than that recorded in horses trotting on a treadmill, where the forces exerted on one limb were similar to the horse's body weight. The results of this study indicate that the Tekscan F-SCAN system is not ideally suited to measure the force of a kick of a horse in vivo.

Various treatment methods have been used for the management of subchondral cystic lesions (SCLs) in horses. Filling the defect with parathyroid hormone fragment peptide 1-34 (PTH1-34) in a fibrin matrix represents a relatively new approach that requires further investigation. For this reason fifteen horses with clinical and radiographic evidence of a total of sixteen SCLs (one horse bilaterally affected) were treated surgically with debridement of the cystic contents and injection of PTH1-34 in a fibrin hydrogel into the cyst cavity. Objectives of the study were to determine the clinical and radiographic outcome of SCLs treated locally with PTH1-34 and to identify factors that may predict outcome. Clinical and radiographic follow-up examinations were carried out at two, four, six and 12 months postoperatively and a telephone inquiry was carried out five to seven years later. The mean age of the horses was 4.9 years. Six SCLs were in the medial condyle of the femur, three in the distal metacarpus, three in the proximal sesamoid bone, two in the first phalanx, one in the patella and one in the calcaneus. Treatment was considered successful in 11 of the 15 cases (73%) because the horses were sound and returned to full work. In the remaining patients, there was improvement in one and no change in three others after treatment. Based on the outcome of this study, PTH1-34 in a fibrin matrix administered directly into the cyst after surgical debridement appears to be a promising treatment option for treating SCLs at various anatomic sites in horses

Exercise intolerance, unwillingness to perform and/or back pain in sports horses are frequently associated with bad saddle fit. Generally, saddles and saddle pads are fitted subjectively and exclusively on the standing horse and rely on the expertise of the saddler. However, for over 16 years, it is possible to objectively assess the pressure distribution underneath the saddle by using a pressure sensitive mat connected to a data logger system. The examination can be carried out in the standing horse as well as while the horse is ridden in different gaits. Saddle pressure measurements were not only performed in the context of saddle fitting, but also to study the interaction between rider and horse. Furthermore, mean and peak saddle pressures were correlated with clinical signs of saddle soreness and back pain in order to define the upper limit pressure values which are still tolerated by the horse. With the help of this device, the critical zones of the saddle area can be detected selectively and the results can be used to convince the rider or saddler of the necessary changes which have to be carried out on the saddle. The respectful co-operation between veterinarians, saddlers and riding instructors is an important prerequisite for an effective and sustainable resolution of the problems encountered in horses with back pain.

Periosteal transection and elevation is a standard treatment for angular limb deformities in foals. It is used to correct axis deviations in the limbs at an early age to assure that the foals grow up with straight limbs to improve their chances to reach their full potential as future athletes. Although clinically proven, its mechanisms of action were never elucidated on a more basic scientific level. In this experimental study the molecular response to periosteal stripping was investigated within the growth plate and adjacent perichondrium. The study was based on the hypothesis that a growth restraining feedback loop related to Indian hedgehog (Ihh), parathyroid hormone related protein (PTHrP) and parathyroid hormone receptors (PTHR) was responsible for the corrective effect of periosteal stripping. Twelve 3 months old lambs underwent periosteal stripping of the distal lateral radius and tibia on one side. The contralateral side served as non-operated controls. Two animals each group were sacrificed at 2, 6, 10, 14, 18 and 21 days after surgery and the growth plates with minimal adjacent bone tissue were harvested for histological investigations. After decalcification, paraffin-embedded sections with routine hematoxylin-eosin stains were prepared to assess morphology and length of growth plates, whereas immunohistochemistry of Ihh, PTHrP, PTHR and the two cytokines fibroblast- (FGF) and transforming growth factor (TGF) was performed to study different protein expression between operated limbs and controls. The results indicate that periosteal stripping caused an up-regulation of Ihh in the early pre- and hypertrophic zone of the growth plate, followed by an increase of PTHrP mainly in the perichondrium, while an increase of PTHR was noticed in all zones, although highest in the perichondrium and hypertrophic zones. The growth factors FGF and TGF were upregulated in all zones, but FGF in response to periosteal stripping was more intensely expressed in the proliferati

In the present study the effects of „periosteal stripping“ on bone and cartilage metabolism of foals with angular limb deformities and healthy experimental lambs were examined. Five foals with angular limb deformities were treated surgically by means of „hemicircumferential transection of the periosteum and periosteal stripping“ (HCTP/HP). Before surgery as well as twice after surgery, 1,25(OH)2Vitamin D, bone and cartilage markers in the serum were determined and compared to 5 healthy foals of the same age. In addition 10 healthy lambs were treated by HCTP/HP, in which the same parameters and bone density were determined. At 22 days after surgery the lambs were sacrificed and treated and control bones were sampled and processed for immunohistochemistry. Neither in foals nor in lambs, significant differences could be observed between treated and untreated animals with regard to the parameters measured in serum. Nevertheless, both treated groups revealed a tendency for higher bone remodelling compared to control animals. This could be the result of an increased bone remodelling rate following surgery. No statistically significant difference in bone mineral density between treated and untreated animals could be detected. In contrast local changes of signal transduction related to parathyroid hormone related protein and indian hedgehog (PTHrP/Ihh) were observed using immunhistochemistry. It was concluded that HCTP/HP at the level of epiphysis and metaphysis does not lead to systemic effects, even though local events detected by immunohistochemistry point to an increased bone formation at the treated site.

Complicated mandibular fractures were recognised in one foal, one pony and four horses. The foal was two months old while the adult animals ranged in age from 12 to 24 years. Three horses had a unilateral horizontal ramus fracture. Two fractures were open and one was closed. Comminution was present in one of these patients while lthe other two horses had marked displacement of the fragments. Two suffered from comminuted fractures of the horizontal and vertical ramus of the mandible. One of these patients had open and infected fractures. One foal had a bilateral horizontal ramus fracture with mrked periosteal "new bone" formation and malalignement which required corrective osteotomy. Each horse underwent locking compression plate (LCP) osteosynthesis consisting of open fracture reduction and application of one to three 4.5/5.0 mm LCP at the ventral, lateral or caudal aspect of the mandible under fluoroscopic control. Two 3.5 mm LCP were used in the foal. Plate fixation was supported by application of a cerclage wire construct between the incisor and premolar teeth in most patients. Complete fracture healing, with excellent functional and cosmetic outcome was achieved in all of the patients. Complications encountered included seroma formation, screw and wire breakage, as well as implant and apical tooth root infections. The LCP was removed after fracture healing had occurred in four patients.

The BoneWelding® Technology offers new opportunities to anchor implants within bone. The technology melted the surface of biodegradable polymer pins by means of ultrasound energy to mould material into the structures of the predrilled bone. Temperature changes were measured at the sites of implantation in an in vitro experiment. In the in vivo part of the study two types of implants were implanted in the limb of sheep to investigate the biocompatibility of the method. One implant type was made of PL-DL-lactide (PLA), the second one was a titanium core partially covered with PLA. Healing period was 2 and 6 months, with 3 sheep per group. Bone samples were evaluated radiologically, histologically and histomorphometrically for bone remodeling and inflammatory reactions. Results demonstrated mild and short temperature increase during insertion. New bone formed at the implant without evidence of inflammatory reaction. The amount of adjacent bone was increased compared to normal cancellous bone. It was concluded that the BoneWelding® Technology proved to be a biocompatible technology to anchor biodegradable as well as titanium-PLA implants in bone.

Reasons for performing study: Osteosynthesis of third metacarpal (McIII) and third metatarsal (MtIII) bone fractures in horses is a surgical challenge and complications surrounding the repair are common. Retrospective studies evaluating surgical repair, complications and outcome are necessary to increase knowledge and improve success of long bone fracture repair in the horse. Objectives: To evaluate clinical findings, surgical repair, post operative complications and outcome of 10 mature horses and 11 foals with McIII or MtIII fractures that were treated with open reduction and internal fixation (ORIF). Methods: Medical records were reviewed and follow-up information obtained by means of radiographs and/or telephone questionnaire. Results: Survival was achieved in 62% of the horses (3 mature/10 foals). On long-term evaluation (>6 months) 11 horses (2 mature/9 foals) were fit for their intended activity, one mature horse had a chronic low grade lameness, and one foal was lost to follow-up because it was sold. The main fracture types were simple transverse (33.3%) or simple oblique (28.6%) and 71.4% of the fractures were open, 3 Type I (one mature/2 foals) and 12 type II (7 mature/5 foals). The preoperative assessment revealed inadequate emergency treatment in 10 horses (5 mature/5 foals; 47.6%). Survival rate of horses with open fractures was 12.5% (1/8) in mature and 85.7% (6/7) in foals. Post operative incisional infection (4 mature, 3 foals) was only managed successfully in 2 foals. Fracture instability related to inadequate fracture fixation technique occurred in 4 horses (all mature) and was always associated with unsuccessful outcome. Conclusions: Age, bodyweight and infection are strongly associated with outcome in treatment of complete McIII/MtIII fractures. Clinical relevance: Rigid fixation using plates and screws can be successful in treatment of closed or open, complete diaphyseal McIII/MtIII fractures in mature horses and foals. Instable fixation, infect

An unusual complication following partial lateral splint bone ectomy is described. Four weeks following the surgery, the horse fell onto the surgery site and from that point on showed a lameness on that limb. Despite a positive local anesthesia, the re-evaluation did not reveal any abnormal ultrasonographic and radiographic findings. The local steroid injection reduced the lameness only slightly. The clinical evaluation at our clinic revealed the potential presence of a fracture in the lateropalmar cortex. The horse was scheduled for surgery and the special fluoroscopic examination prior to surgery confirmed the tentative diagnosis. The origin of the fracture turned out to be the horizontal saw cut in the lateropalmar cortex of McIII, which occurred accidentally during the osteotomy of the fractured splint bone. The fall of the horse onto the partially amputated splint bone in association with the horizontal cut in the lateropalmar cortex of McIII, resulted in this avulsion fracture associated with significant pain. The splint bone and the fracture were stabilized with the help of a 9-hole 3.5 mm DCP applied over the splint bone and with the screws traversing the entire lateropalmar cortex of McIII. The horse responded positively to this treatment and 10 weeks postoperatively the plate was removed. An additional reason for this relatively early plate removal was the presence of an additional suspensory problem, which demanded a prolonged recovery period.

The objective of this postmortem study was to determine the fracture configurations of the equine radius and tibia after a simulated kick. Fracture configurations of 35 radii and 36 tibiae from 19 adult horses were evaluated after a simulated kick in an experimental exvivo study. The bones were dissected, the proximal and distal ends were embedded in resin, fixed horizontally and preloaded in compression, and a steel impactor, designed to simulate a shod equine hoof, was dropped from a height of three to six metres onto the diaphysis. The experiments were filmed with a high-speed camera (30,000 pictures/second). The bones were then photographed and radiographed using a C-arm based 3D imaging device. A software programme (Osirix) was used to reconstruct the fissured and fractured bones three-dimensionally on a computer screen for assessment of the fracture configuration and fissure lines. Incomplete fractures occurred in 26 bones and complete fractures in 42. The complete fractures included 22 butterfly and 20 simple fractures; the latter included 17 oblique, two transverse and one longitudinal fracture. Additional longitudinal fissures occurred in 98% of the fractures. The butterfly fragment was always located on the side opposite the impact. There was a significant correlation between the type of bone and the fracture configuration: butterfly and oblique fractures occurred more frequently in the tibia, and incomplete fractures occurred more frequently in the radius. The data collected can be used to optimize evaluation of fractures and fissures caused by a kick and thereby improve surgical stabilization.

BACKGROUND: In an attempt to establish some consensus on the proper use and design of experimental animal models in musculoskeletal research, AOVET (the veterinary specialty group of the AO Foundation) in concert with the AO Research Institute (ARI), and the European Academy for the Study of Scientific and Technological Advance, convened a group of musculoskeletal researchers, veterinarians, legal experts, and ethicists to discuss, in a frank and open forum, the use of animals in musculoskeletal research. METHODS: The group narrowed the field to fracture research. The consensus opinion resulting from this workshop can be summarized as follows: RESULTS & CONCLUSION: Anaesthesia and pain management protocols for research animals should follow standard protocols applied in clinical work for the species involved. This will improve morbidity and mortality outcomes. A database should be established to facilitate selection of anaesthesia and pain management protocols for specific experimental surgical procedures and adopted as an International Standard (IS) according to animal species selected. A list of 10 golden rules and requirements for conduction of animal experiments in musculoskeletal research was drawn up comprising 1) Intelligent study designs to receive appropriate answers; 2) Minimal complication rates (5 to max. 10%); 3) Defined end-points for both welfare and scientific outputs analogous to quality assessment (QA) audit of protocols in GLP studies; 4) Sufficient details for materials and methods applied; 5) Potentially confounding variables (genetic background, seasonal, hormonal, size, histological, and biomechanical differences); 6) Post-operative management with emphasis on analgesia and follow-up examinations; 7) Study protocols to satisfy criteria established for a "justified animal study"; 8) Surgical expertise to conduct surgery on animals; 9) Pilot studies as a critical part of model validation and powering of the definitive study design; 10) Criteria

Mit der zunehmenden Bedeutung der Gruppenhaltung von Pferden ist die Tierärzteschaft gefordert mitzuhelfen, das Verletzungsrisiko in Gruppenhaltungssystemen zu verringern. Dem Vermeiden von Schlag- und Bissverletzungen kommt hierbei eine zentrale Bedeutung zu. Präventive Maßnahmen konzentrieren sich im Wesentlichen auf die Gruppenzusammensetzung und Eingliederung neuer Pferde sowie auf die Gestaltung der Haltungssysteme. Die Raumaufteilung und die Fütterungstechnik müssen equidentypisches Verhalten (Lokomotion, langandauernde Futteraufnahme und schadensfreie soziale Interaktionen) erlauben. Es gilt, Kenntnisse über Zusammenhänge zwischen Haltung, Fütterung, Nutzung, Verhalten und Gesundheit an Pferdehalter und Stallbaufirmen weiterzugeben.