Cartogenina associada à microperfuração do osso subcondral na reparação da cartilagem articular em equinos / Kartogenin associated to micro of the subchondral bone in the joint cartilage repair in horses

A reconstituição da cartilagem articular danificada por doenças de desenvolvimento, trauma e osteoartrite tem sido um grande desafio na veterinária. O objetivo do presente estudo foi avaliar o uso da cartogenina, uma molécula capaz de induzir diferenciação de células mesenquimais em condrócitos, associado ou não à técnica de microfratura na reparação de defeitos condrais induzidos na tróclea femoral de equinos. Foram utilizados seis equinos pesando em média (±DP) 342±1,58kg, com idade de 7,2±1,30 anos e escore corporal de 7,1±0,75, os quais foram submetidos à videoartroscopia para indução da lesão condral de 1cm2 na tróclea lateral do fêmur e à realização da técnica de microperfuração do osso subcondral de ambos os joelhos. Foram realizadas quatro aplicações semanais com 20µM de cartogenina intra-articular em um dos joelhos (grupo tratado) e solução de ringer com lactato na articulação contralateral (grupo controle). Os animais foram submetidos a avaliações física, radiográfica, ultrassonográfica, por um período de 60 dias. Não houve qualquer diferença estatística entre as articulações tratadas e as controle. A terapia com cartogenina, segundo protocolo utilizado, não produziu melhora clínica em lesões osteocondrais induzidas e tratadas com microperfurações na tróclea lateral do fêmur em equinos.(AU)

Articular cartilage reconstruction is still a challenge in Veterinary Medicine. The aim was to evaluate the therapeutic effects of kartogenin, a small molecule that promotes chondrocyte differentiation, in the repair of induced chondral defects pretreated with subchondral drilling. Six horses with a mean (± SD) weight of 342 ± 1.58Kg, aging 7.2 ± 1.30 years, and with a mean 7.1 ± 0.75 body score condition were used. In both stifles, a 1cm2 chondral defect was induced in the lateral femoral trochlea followed by treatment with subchondral drilling. Four intra-articular injections with kartogenin (20mM) were performed weekly in one stifle (treated group). The same procedure using saline solution was performed in the contralateral joint (control group). Clinical, radiographic, ultrasound evaluations were performed for a period of 60 days. No statistical differences were detected between groups in any of the studied variables. Although kartogenin has shown to improve articular cartilage repair in laboratory animal models, the same was not observed in this equine model. In conclusion, the kartogenin therapy, according to the used protocol, did not promote any clinical benefit in equine femoral trochlear defects pretreated with subcondral drilling.(AU)

Treatment of subchondral lucencies in the medial proximal radius with a bone screw in 8 horses.

OBJECTIVE: To describe the results of screw placement through subchondral lucencies (SCL) of the proximal radius in 8 horses. STUDY DESIGN: Retrospective clinical study. ANIMALS: Horses with cubital SCL causing lameness (n=8). METHODS: Medical record review and clinical follow-up. RESULTS: Eight horses with SCL in the proximal radius causing lameness were treated with a screw placed across the lucency. The horses range in age from 1 to 20 years. In 4 of 8 horses, the lameness had been intermittently severe (apparent at the walk). Lameness was isolated to the cubital joint by intra-articular anesthesia in 5 horses and diagnosed radiographically in all 8. All horses had a 4.5 mm cortical bone screw placed from medial to lateral (6 lag, 2 neutral) across the SCL using fluoroscopic or radiographic control. Postoperative care included stall confinement with hand walking for 30-60 days, followed by an additional 30-60 days of pasture turnout. Radiographic SCL healing (reduction in SCL size) was demonstrated at 3-4 months after surgery in all horses, and 7/8 horses (87.5%) were used as intended (4 performance, 3 pasture turn-out) within 6 months. Lameness in the remaining horse improved initially (dressage) but returned. CONCLUSIONS: A screw placed through the SCL of the proximal-medial radius was effective in reducing or resolving lameness associated with the elbow joint in 7/8 horses (88%). Screw placement in the proximal radius should be considered for horses with lameness caused by an SCL when a quick return to exercise is desired or conservative therapy is ineffective.

Chondroitin sulfate and glucosamine in the cartilage and subchondral bone repair of dogs - Histological findings / Sulfato de condroitina e glucosamina na reparação da cartilagem e do osso subcondral de cães - Achados histológicos

Chondroitin and glucosamine sulfate nutraceuticals are commonly used in the management of degenerative articular disease in veterinary routine. However, there are controversies on the contribution of these substances to articular cartilage. The purpose of this study was to evaluate the efficiency of a chondroitin and glucosamine sulfate-based veterinary nutraceutical on the repair of an induced osteochondral defect in a dog femoral condyle, by macroscopic, histological and histomorphometric analyses. The nutraceutical was orally administered the day following injury induction, every 24 hours (treated group, TG, n=24), compared with animals that did not receive the product (control group, CG, n=24). Six animals per group were anaesthetized for sample collection at 15, 30, 60 and 90 days after surgery. At 15 days, defects were macroscopically filled with red-pinkish tissue. After 30 days, whitish color tissue was observed, both in TG and CG animals, with firmer consistency to touch at 60 and 90 postoperative days. Histological analysis demonstrated that, in both groups, there was initial blood clot formation, which was subsequently substituted by a fibrin net, with capillary proliferation from the adjacent bone marrow and infiltration of mesenchymal cells in clot periphery. As cellular differentiation developed, repair tissue presented a fibrocartilage aspect most of the time, and new subchondral bone formation occurred in the deepest area corresponding to the defect. Histomorphometry suggested that the nutraceutical did not favor the articular cartilage repair process. It was concluded that nutraceutical did not significantly influence chondrocytes proliferation or hyaline architecture restoration.(AU)

Os nutracêuticos compostos de sulfato de condroitina e glucosamina são comumente utilizados no manejo da doença articular degenerativa na rotina veterinária. Entretanto, existem controvérsias sobre a contribuição dessas substâncias à cartilagem articular. O objetivo deste trabalho foi avaliar a eficácia de um nutracêutico veterinário à base de sulfato de condroitina e glucosamina na reparação de defeitos osteocondrais induzidos no côndilo femoral de cães, através de análises macroscópica, histológica e histomorfométrica. O nutracêutico foi administrado no dia seguinte à indução da lesão, pela via oral, a cada 24 horas (grupo tratado - GT, 24 animais), sendo comparado a animais que não receberam o produto (grupo controle - GC, de igual número de animais). Aos 15, 30, 60 e 90 dias após a cirurgia, seis animais por grupo foram anestesiados para ser realizada a coleta das amostras. Aos 15 dias, os defeitos eram macroscopicamente preenchidos por tecido de coloração rósea a avermelhada. Já a partir dos 30 dias, observou-se preenchimento por tecido de coloração esbranquiçada, tanto nos animais do GT quanto nos do GC, com consistência mais firme ao toque digital aos 60 e 90 dias de pós-operatório. A análise histológica revelou que, em ambos os grupos, houve inicialmente formação de coágulo sanguíneo que, posteriormente, foi substituído por uma rede de fibrina, com proliferação de capilares a partir da medula óssea adjacente e infiltração de células mesenquimais na periferia do coágulo. À medida que se processou a diferenciação celular, o tecido de reparação se apresentou na maioria das vezes com aspecto de fibrocartilagem e, na região mais profunda da área correspondente ao defeito, ocorreu formação de osso novo subcondral. A histomorfometria sugeriu que o nutracêutico não favoreceu o processo de reparação da cartilagem articular. Concluiu-se que o nutracêutico não influenciou consideravelmente na proliferação de condrócitos nem na restauração da arquitetura hialina.(AU)

Comparison of three drilling techniques for carpometacarpal joint arthrodesis in horses.

OBJECTIVE: To evaluate 3 drilling techniques for arthrodesis of the equine carpometacarpal (CMC) joint. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric equine forelimbs (n=15). METHODS: Limbs were divided into 3 groups (5 limbs each) to evaluate 3 drilling techniques: (1) use of a 4.5 mm drill bit inserted into the joint through 4 entry points and moved in a fanning motion; (2) a 5.5 mm drill bit inserted through 2 entry points to create 3 nonfanned drill tracts (3 drill technique); and (3) a 4.5 mm drill bit used in a 3 drill technique. The CMC joint was disarticulated after drilling, and cartilage and subchondral bone damage evaluated visually and by gross and microradiographic examination using planimetry. RESULTS: Technique 1 produced significantly more damage of the proximal surface, but significantly less to the subchondral bone of the distal surface. Technique 1 produced the most damage to both the articular cartilage and subchondral bone of the total CMC joint than either of the 3 drill tract techniques; however, the difference between techniques 1 and 2 was not significant. Damage from technique 3 was significantly less than that with techniques 1 or 2. CONCLUSIONS: Techniques 1 and 2 produced the most cartilage and subchondral bone damage with technique 2 changes more equally distributed between proximal and distal joint surfaces. CLINICAL RELEVANCE: Technique 1 (fanning) and 2 (5.5 mm 3 drill tracts) may be preferable to achieve arthrodesis of the CMC joint. Morbidity and efficacy of these arthrodesis techniques need to be evaluated in vivo.

Long-term outcome in 44 horses with stifle lameness after arthroscopic exploration and debridement.

OBJECTIVE: To (1) examine the outcome in horses with osteoarthritis or intra-articular soft tissue injuries of the stifle after arthroscopic exploration and debridement and (2) to determine any imaging or surgical findings that may influence prognosis. DESIGN: Case series. ANIMALS: Horses (n=44) with lameness referable to the stifle, diagnosed with osteoarthritis, meniscal tears, or other intra-articular soft tissue injuries based on arthroscopic examination. METHODS: Medical records of horses with stifle lameness that had arthroscopic exploration were reviewed. Horses with osteochondrosis lesions, intra-articular fractures, or osseous cyst-like lesions were excluded. Pertinent case information was analyzed and short- and long-term outcome was assessed. RESULTS: There was no association between radiographic score and surgery score. Diagnostic ultrasound had a sensitivity of 79% and a specificity of 56% for identifying meniscal injuries. Follow-up information was available for 35 horses; 23 horses (60%) improved after surgery, 16 (46%) became sound, and 13 (37%) returned to their previous level of function. A negative association was observed between age and degree of preoperative lameness and outcome. More severe changes observed on preoperative radiographs were also negatively associated with prognosis. No horses with grade 3 meniscal tears improved postoperatively and increasing meniscal pathology was negatively associated with return to previous function. A weak association between surgery grade and outcome was also observed. Degree of chondral damage, location of primary pathology, and microfracture techniques had no effect on outcome. CONCLUSIONS: Advanced horse age, severe lameness and preoperative radiographic changes, and presence of large meniscal tears are associated with a negative postoperative outcome for horses with stifle lameness. Appearance of the articular surface at surgery appears to be an inconsistent prognostic indicator. CLINICAL RELEVANCE: Some horses with extensive cartilage damage may return to athletic function after arthroscopic debridement and lavage. A more pessimistic prognosis may be given to older horses, those with more severe preoperative lameness, and those with severe radiographic changes or large meniscal tears.