Technique for guttural pouch bead removal using a novel three-dimensional (3D)-printed instrument.

OBJECTIVE: The aim of the present study was to determine if a three-dimensional (3D)-printed instrument technique would improve lavage removal of plastic beads (guttural pouch [GP] chondroid mimics) through a dorsal pharyngeal recess (DPR) fenestration. We hypothesized that using a 3D-printed instrument placed through the DPR fenestration would remove more beads, reduce lavage time and incur less soft tissue damage than using a lavage tube control or instrument placement through the salpingopharyngeal ostium (SPO). STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: A total of 30 cadaveric equine heads. METHODS: DPR fenestration was performed using transendoscopic laser and 50 plastic 12 mm beads were placed into one GP of horse heads. Four removal procedures using a 3D-printed instrument or lavage tube control placed through the DPR fenestration or the SPO were compared. Number of beads removed and number of 2-min lavage cycles to recover ≥96% of beads or three consecutive no-yield cycles were recorded. Endoscopic soft tissue damage was graded. Data were compared by generalized estimating equations (GEE) model and Fisher's exact test (p < .05). RESULTS: More beads (median 48 beads; range 0-49) were removed faster (median 24 beads/cycle; range 12-50) using the 3D-printed instrument compared to control (median 6 beads; range 0-29, 0.66 beads/cycle, range 0-49). There was no difference between total beads removed or removal speed between placement sites. There was no difference in soft tissue damage between procedures. CONCLUSION: Our 3D-printed instrument enabled efficient plastic bead removal. CLINICAL SIGNIFICANCE: DPR fenestration and use of our 3D-printed instrument represents an alternative to current chondroid removal techniques, warranting investigation in clinical cases.

Inflamed synovial fluid induces a homeostatic response in bone marrow mononuclear cells in vitro: Implications for joint therapy.

Synovial inflammation is a central feature of osteoarthritis (OA), elicited when local regulatory macrophages (M2-like) become overwhelmed, activating an inflammatory response (M1-like). Bone marrow mononuclear cells (BMNC) are a source of naïve macrophages capable of reducing joint inflammation and producing molecules essential for cartilage metabolism. This study investigated the response of BMNC to normal (SF) and inflamed synovial fluid (ISF). Equine BMNC cultured in autologous SF or ISF (n = 8 horses) developed into macrophage-rich cultures with phenotypes similar to cells native to normal SF and became more confluent in ISF (~100%) than SF (~25%). BMNC cultured in SF or ISF were neither M1- nor M2-like, but exhibited aspects of both phenotypes and a regulatory immune response, characterized by increasing counts of IL-10+ macrophages, decreasing IL-1ß concentrations and progressively increasing IL-10 and IGF-1 concentrations. Changes were more marked in ISF and suggest that homeostatic mechanisms were preserved over time and were potentially favored by progressive cell proliferation. Collectively, our data suggest that intra-articular BMNC could increase synovial macrophage counts, potentiating the macrophage- and IL-10-associated mechanisms of joint homeostasis lost during the progression of OA, preserving the production of cytokines involved in tissue repair (PGE2 , IL-10) generally impaired by frequently used corticosteroids.

Autologous bone marrow mononuclear cells modulate joint homeostasis in an equine in vivo model of synovitis.

Osteoarthritis (OA) is characterized by macrophage-driven synovitis. Macrophages promote synovial health but become inflammatory when their regulatory functions are overwhelmed. Bone marrow mononuclear cells (BMNCs) are a rich source of macrophage progenitors used for treating chronic inflammation and produce essential molecules for cartilage metabolism. This study investigated the response to autologous BMNC injection in normal and inflamed joints. Synovitis was induced in both radiocarpal joints of 6 horses. After 8 h, 1 inflamed radiocarpal and 1 normal tarsocrural joint received BMNC injection. Contralateral joints were injected with saline. Synovial fluid was collected at 24, 96, and 144 h for cytology, cytokine quantification, and flow cytometry. At 144 h, horses were euthanatized, joints were evaluated, and synovium was harvested for histology and immunohistochemistry. Four days after BMNC treatment, inflamed joints had 24% higher macrophage counts with 10% more IL-10+ cells than saline-treated controls. BMNC-treated joints showed gross and analytical improvements in synovial fluid and synovial membrane, with increasing regulatory macrophages and synovial fluid IL-10 concentrations compared with saline-treated controls. BMNC-treated joints were comparable to healthy joints histologically, which remained abnormal in saline-treated controls. Autologous BMNCs are readily available, regulate synovitis through macrophage-associated effects, and can benefit thousands of patients with OA.-Menarim, B. C., Gillis, K. H., Oliver, A., Mason, C., Ngo, Y., Werre, S. R., Barrett, S. H., Luo, X., Byron, C. R., Dahlgren, L. A. Autologous bone marrow mononuclear cells modulate joint homeostasis in an equine in vivo model of synovitis.

Treatment of Infiltrative Superficial Tumors in Awake Standing Horses Using Novel High-Frequency Pulsed Electrical Fields.

Irreversible electroporation is a proven ablation modality for local ablation of soft tissue tumors in animals and humans. However, the strong muscle contractions associated with the electrical impulses (duration, 50-100 µs) requires the use of general anesthesia and, in most situations, application of neuromuscular blockade. As such, this technology is not used in an outpatient setting for ablating common cutaneous tumors (e.g., squamous cell carcinoma or melanoma) in humans or animals. Recently, high-frequency irreversible electroporation (H-FIRE) technology has been developed to enable electroporation of tumors without stimulation of nearby skeletal muscle. H-FIRE administers bursts of electrical pulses (duration, 0.5-2 µs) through bipolar electrodes placed in tumor parenchyma. We hypothesized that H-FIRE could be used to safely ablate superficial tumors in standing, awake horses without the need for general anesthesia. Here, we describe the treatment of superficial tumors in five horses using this novel ablation therapy without the need for general anesthesia. In each case, H-FIRE therapy predictably ablated tumor volume. All patients tolerated the procedure, no complications developed, and veterinary personnel safety was maintained. The H-FIRE treatment may be useful for treatment in veterinary and human patients in an outpatient setting without the need for hospitalization, general anesthesia, and advanced monitoring techniques.

Comparison of the Effects of Interleukin-1 on Equine Articular Cartilage Explants and Cocultures of Osteochondral and Synovial Explants.

Osteoarthritis (OA) is a ubiquitous disease affecting many horses. The disease causes chronic pain and decreased performance for patients and great cost to owners for diagnosis and treatment. The most common treatments include systemic non-steroidal anti-inflammatory drugs and intra-articular injection of corticosteroids. There is excellent support for the palliative pain relief these treatments provide; however, they do not arrest progression and may in some instances hasten advancement of disease. Orthobiologic treatments have been investigated as potential OA treatments that may not only ameliorate pain but also prevent or reverse pathologic articular tissue changes. Clinical protocols for intra-articular use of such treatments have not been optimized; the high cost of in vivo research and concerns over humane use of research animals may be preventing discovery. The objective of this study was to evaluate a novel in vitro articular coculture system for future use in OA treatment research. Concentrations and fold increases in various markers of inflammation (prostaglandin E2 and tumor necrosis factor-alpha), degradative enzyme activity [matrix metalloproteinase-13 (MMP-13)], cartilage and bone metabolism (bone alkaline phosphatase and dimethyl-methylene blue), and cell death (lactate dehydrogenase) were compared between IL-1-stimulated equine articular cartilage explant cultures and cocultures comprised of osteochondral and synovial explants (OCS). Results suggested that there are differences in responses of culture systems to inflammatory stimulation. In particular, the IL-1-induced fold changes in MMP-13 concentration were significantly different between OCS and cartilage explant culture systems after 96 h. These differences may be relevant to responses of joints to inflammation in vivo and could be important to the biological relevance of in vitro research findings.

Evaluation of the reasons for and outcomes of gastrointestinal tract surgery in pet pigs: 11 cases (2004-2015).

OBJECTIVE To evaluate the reasons for and outcomes of gastrointestinal tract surgery in pet pigs. DESIGN Retrospective case series. ANIMALS 11 pigs. PROCEDURES The medical record database of a teaching hospital was searched to identify pet pigs that underwent at least 1 celiotomy because of a possible gastrointestinal tract obstruction between 2004 and 2015. For each pig, information extracted from the medical record included history; signalment; clinical signs; physical examination, diagnostic imaging, and diagnostic test results; perioperative management; surgical diagnosis, duration, and procedures performed; postoperative complications; and outcome. Descriptive data were generated. RESULTS 11 pet pigs underwent 12 celiotomies during the study period. Five pigs with intestinal obstructions caused by foreign bodies survived to hospital discharge. Four pigs were euthanized during surgery: 2 because of extensive adhesions that prevented correction of an intestinal obstruction, 1 because of a perforated spiral colon, and 1 because of neoplasia. One pig with a fecal impaction in the spiral colon died during anesthetic recovery. A diagnosis was not achieved for 1 pig, which was euthanized after surgery because of a deteriorating clinical condition. For the pig that underwent 2 celiotomies, the first procedure was an enterotomy for removal of a foreign body, and the second was an intestinal bypass of a stricture caused by adhesions at the previous enterotomy site. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated prognosis was good for pet pigs following surgical removal of gastrointestinal foreign bodies; however, the presence or development of intra-abdominal adhesions appeared to adversely affect prognosis.

Femoral head ostectomy and medial patellar ligament desmotomy to treat a pregnant miniature horse with coxofemoral joint luxation and upward fixation of the patella.

A 2-year-old, 8-weeks pregnant, non-weight bearing miniature horse mare was treated for a 6-day-old left coxofemoral joint luxation with a femoral head ostectomy. The procedure had no negative effects on pregnancy or parturition and 23 months following surgery the horse had minimal lameness.

Ostectomie de la tête fémorale et desmotomie du ligament patellaire médial pour traiter une jument miniature gravide atteinte d'une luxation de l'articulation coxofémorale et d'une fixation supérieure de la rotule. Une jument miniature non portante gravide de 8 semaines et âgée de 2 ans a été traitée pour une luxation de l'articulation coxofémorale gauche datant de 6 jours à l'aide d'une ostectomie de la tête fémorale. L'intervention n'a pas eu d'effets négatifs sur la gestation ou la parturition et 23 mois après la chirurgie, la jument présentait une boiterie minime.(Traduit par Isabelle Vallières).

Frontal and caudal maxillary sinus lipoma in a horse.

An adult horse was diagnosed with a frontal and caudal maxillary sinus lipoma, which was surgically removed. This is the first known report of a sinus lipoma in a horse. Lipomas should be considered in the differential diagnoses of equine sinus masses; complete surgical excision appears to be curative.

Lipome du sinus maxillaire frontal et caudal chez un cheval. Un cheval adulte a été diagnostiqué avec un lipome du sinus maxillaire frontal et caudal qui a été enlevé par chirurgie. Il s'agit du premier rapport d'un lipome de sinus chez un cheval. Les lipomes devraient être considérés dans les diagnostics différentiels des masses des sinus chez les équidés; l'excision chirurgicale complète semble être curative.(Traduit par Isabelle Vallières).

End-to-Side Versus Side-to-Side Jejunocecostomy in Horses: A Retrospective Analysis of 150 Cases.

OBJECTIVES: To determine factors associated with postoperative reflux, postoperative colic, repeat celiotomy, and survival in horses after end-to-side (E2S) or side-to-side (S2S) jejunocecostomy. STUDY DESIGN: Retrospective, multicenter study. SAMPLE POPULATION: Horses (n = 150). METHODS: Admissions, intra- and postoperative data were collected from medical records of horses that had E2S or S2S jejunocecostomy. Descriptive statistics were calculated and data were analyzed using parametric and nonparametric tests, linear and multivariate logistic regression with significance set at P < .05. Kaplan-Meier estimate of the survival function was performed. RESULTS: One hundred fifty horses (S2S = 90, E2S = 60) were included. S2S procedures were performed using staples (n = 57) or hand-sewn (33). Method of anastomosis was not significantly associated with development of postoperative reflux or colic, repeat celiotomy, whether the horse was alive at hospital discharge or 12 months after discharge. The number of years that the principal surgeon was boarded by the American College of Veterinary Surgeons significantly affected whether the horse was discharged from the hospital alive (P = .003). Age (P = .006) was significantly associated with 12-month survival. Increased age (P = .013) and administration of prokinetic medication (P = .0006) were significantly associated with development of postoperative reflux. Sixty-eight (76%) horses with S2S and 52 (87%) horses with E2S were discharged alive. CONCLUSION: Age, patient related variables, and surgeon experience may influence morbidity and mortality more than method of jejunocecostomy.

Surgical repair of a cleft palate in an American bison (Bison bison).

A 4-mo-old bison (Bison bison) was evaluated and treated at a university veterinary hospital for a cleft defect in the hard and soft palate. Using a mandibular symphysiotomy approach, the palatal defect was repaired with a Z-plasty pattern in the soft palate and mucoperiosteal flaps in the hard palate. A small area of dehiscence in the rostral aspect of the hard palate, and aspiration pneumonia, were complications, but the bison calf recovered with medical management. Even though this surgical procedure has a high potential for complications, the described technique allowed return to normal feeding and resolution of the aspiration pneumonia by 14 mo postsurgery.

In vitro expression of receptor activator of nuclear factor-kappaB ligand and osteoprotegerin in cultured equine articular cells.

OBJECTIVE: To determine concentrations of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) in equine chondrocytes and synoviocytes and to quantify changes in the OPG:RANKL ratio in response to exogenous factors. SAMPLE POPULATION: Samples of articular cartilage and synovium with grossly normal appearance obtained from metacarpophalangeal and metatarsophalangeal joints of 5 adult (1- to 8-year-old) horses. PROCEDURES: Cell cultures of chondrocytes and synoviocytes were incubated with human recombinant interleukin-1beta (hrIL-1beta; 10 ng/mL), lipopolysaccharide (LPS; 10 microg/mL), or dexamethasone (100nM) for 48 hours. Negative control cultures received no treatment. Cells and spent media were assayed for RANKL and OPG concentrations by use of western blot and immunocytochemical analyses. Spent media were also assayed for OPG concentration by use of an ELISA. RESULTS: RANKL and OPG were expressed in equine chondrocytes and synoviocytes in vitro. Cell-associated RANKL and OPG concentrations were not impacted by exogenous factors. Soluble RANKL release into media was significantly increased by hrIL-1beta in chondrocyte but not in synoviocyte cultures. Soluble OPG release into media was significantly increased by hrIL-1beta and LPS in chondrocyte but not in synoviocyte cultures. The soluble OPG:RANKL ratio was significantly increased by LPS in chondrocyte cultures. Dexamethasone decreased OPG expression in synoviocytes. CONCLUSIONS AND CLINICAL RELEVANCE: RANKL and OPG proteins were expressed in equine articular cells. Release of these proteins may affect osteoclastogenesis within adjacent subchondral bone. Thus, RANKL and OPG may have use as biomarkers and treatment targets in horses with joint disease.

Modified tenoscopic method for carpal flexor retinaculum release in a horse.

OBJECTIVE: To report the use of a proximolateral endoscopic portal with a distolateral instrument portal for carpal retinaculum release in a horse clinically affected with carpal canal syndrome. STUDY DESIGN: Clinical report. ANIMALS: A 4-year-old Thoroughbred female. METHODS: Carpal canal syndrome secondary to traumatic suppurative tenosynovitis was treated by accessory carpal bone debridement and carpal retinaculum release using a tenoscopic approach to the carpal flexor synovial sheath through a proximolateral endoscope portal and a distolateral instrument portal. RESULTS: Resolution of carpal sheath effusion and lameness occurred allowing racing 14 months later. Use of a distolateral instrument portal was not associated with complications or iatrogenic damage to neurovascular structures and reduced endoscope and instrument interference and offered easier access to the distal aspect of the carpal sheath. CONCLUSIONS: Carpal retinaculum release may be safely accomplished with a distolateral instrument portal when access to the distal aspect of the carpal sheath is needed. CLINICAL RELEVANCE: The distolateral instrument portal described may be a useful alternative to a proximolateral portal when distal carpal sheath instrument access is necessary or advantageous.

Comparison of equine tendon-, muscle-, and bone marrow-derived cells cultured on tendon matrix.

OBJECTIVE: To compare viability and biosynthetic capacities of cells isolated from equine tendon, muscle, and bone marrow grown on autogenous tendon matrix. SAMPLE POPULATION: Cells from 4 young adult horses. PROCEDURES: Cells were isolated, expanded, and cultured on autogenous cell-free tendon matrix for 7 days. Samples were analyzed for cell viability, proteoglycan synthesis, collagen synthesis, and mRNA expression of collagen type I, collagen type III, and cartilage oligomeric matrix protein (COMP). RESULTS: Tendon- and muscle-derived cells required less time to reach confluence (approx 2 weeks) than did bone marrow-derived cells (approx 3 to 4 weeks); there were fewer bone marrow-derived cells at confluence than the other 2 cell types. More tendon- and muscle-derived cells were attached to matrices after 7 days than were bone marrow-derived cells. Collagen and proteoglycan synthesis by tendon- and muscle-derived cells was significantly greater than synthesis by bone marrow-derived cells. On a per-cell basis, tendon-derived cells had more collagen synthesis, although this was not significant. Collagen type I mRNA expression was similar among groups. Tendon-derived cells expressed the highest amounts of collagen type III and COMP mRNAs, although the difference for COMP was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Tendon- and muscle-derived cells yielded greater cell culture numbers in shorter time and, on a per-cell basis, had comparable biosynthetic assays to bone marrow-derived cells. More in vitro experiments with higher numbers may determine whether tendon-derived cells are a useful resource for tendon healing.

Effect of dexamethasone supplementation on chondrogenesis of equine mesenchymal stem cells.

OBJECTIVE: To determine whether expansion of equine mesenchymal stem cells (MSCs) by use of fibroblast growth factor-2 (FGF-2) prior to supplementation with dexamethasone during the chondrogenic pellet culture phase would increase chondrocytic matrix markers without stimulating a hypertrophic chondrocytic phenotype. SAMPLE POPULATION: MSCs obtained from 5 young horses. PROCEDURES: First-passage equine monolayer MSCs were supplemented with medium containing FGF-2 (0 or 100 ng/mL). Confluent MSCs were transferred to pellet cultures and maintained in chondrogenic medium containing 0 or 10(7)M dexamethasone. Pellets were collected after 1, 7, and 14 days and analyzed for collagen type II protein content; total glycosaminoglycan content; total DNA content; alkaline phosphatase (ALP) activity; and mRNA of aggrecan, collagen type II, ALP, and elongation factor-1alpha. RESULTS: Treatment with FGF-2, dexamethasone, or both increased pellet collagen type II content, total glycosaminoglycan content, and mRNA expression of aggrecan. The DNA content of the MSC control pellets decreased over time. Treatment with FGF-2, dexamethasone, or both prevented the loss in pellet DNA content over time. Pellet ALP activity and mRNA were increased in MSCs treated with dexamethasone and FGF-2-dexamethasone. After pellet protein data were standardized on the basis of DNA content, only ALP activity of MSCs treated with FGF-2-dexamethasone remained significantly increased. CONCLUSIONS AND CLINICAL RELEVANCE: Dexamethasone and FGF-2 enhanced chondrogenic differentiation of MSCs, primarily through an increase in MSC numbers. Treatment with dexamethasone stimulated ALP activity and ALP mRNA, consistent with the progression of cartilage toward bone. This may be important for MSC-based repair of articular cartilage.

Effect of fibroblast growth factor-2 on equine mesenchymal stem cell monolayer expansion and chondrogenesis.

OBJECTIVE: To determine whether fibroblast growth factor-2 (FGF-2) treatment of equine mesenchymal stem cells (MSCs) during monolayer expansion enhances subsequent chondrogenesis in a 3-dimensional culture system. ANIMALS: 6 healthy horses, 6 months to 5 years of age. PROCEDURES: Bone marrow-derived MSCs were obtained from 6 horses. First-passage MSCs were seeded as monolayers at 10,000 cells/cm(2) and in medium containing 0, 1, 10, or 100 ng of FGF-2/mL. After 6 days, MSCs were transferred to pellet cultures (200,000 cells/pellet) and maintained in chondrogenic medium. Pellets were collected after 15 days. Pellets were analyzed for collagen type II content by use of an ELISA, total glycosaminoglycan content by use of the dimethylmethylene blue dye-binding assay, and DNA content by use of fluorometric quantification. Semiquantitative PCR assay was performed to assess relative concentrations of collagen type II and aggrecan mRNAs. RESULTS: Use of 100 ng of FGF-2/mL significantly increased pellet DNA and glycosaminoglycan content. Collagen type II content of the pellet was also increased by use of 10 and 100 ng of FGF-2/mL. Collagen type II and aggrecan mRNA transcripts were increased by treatment with FGF-2. Some control samples had minimal evidence of collagen type II and aggrecan transcripts after 35 cycles of amplification. CONCLUSIONS AND CLINICAL RELEVANCE: FGF-2 treatment of bone marrow-derived MSC monolayers enhanced subsequent chondrogenic differentiation in a 3-dimensional culture. This result is important for tissue engineering strategies dependent on MSC expansion for cartilage repair.

Use of a condylar screw plate for repair of a Salter-Harris type-III fracture of the femur in a 2-year-old horse.

A 2-year-old sexually intact male Paint horse weighing 427 kg (940 lb) was admitted for examination and treatment of intermittent non-weight-bearing lameness of the right hind limb of 1 week's duration. Radiography revealed a displaced Salter-Harris type-III fracture of the right femoral condyle with the sagittal component of the fracture line located in the intercondylar space and the transverse component exiting on the medial aspect of the femur. The fracture was repaired with a condylar screw plate designed for repair of femoral condylar fractures in humans. The owner reported by telephone 9 months after surgery that the horse was sound. To our knowledge, use of this particular implant system for fixation of a Salter-Harris type-III fracture on the medial side of the femur in a horse has not been described. Results in this horse suggest that this implant can be successfully used for repair of femoral condylar fractures in selected adult horses.