The effects of intra-articular methylprednisolone and exercise on the mechanical properties of articular cartilage in the horse

AbstractIntroduction: Intra-articular corticosteroids are widely used as anti-inflammatory agents for symptomatic management of arthritis, but their administration with concurrent exercise remains controversial. Biochemical and morphologic analysis of treated cartilage has revealed conflicting results, but previous biomechanical assessment has not been undertaken.Objective: To compare the biomechanical properties of intra-articular methylprednisolone acetate (MPA) and diluent treated cartilage in treadmill exercised horses.Methods: Eight 2-year-old female horses had MPA or diluent administered into contralateral middle carpal joints at 14 day intervals for a total of four treatments per horse. Horses underwent a standard treadmill exercise protocol until euthanasia (day 70). Standard sites were tested on the third, radial and intermediate carpal bones using an automated indentation apparatus to obtain the creep and recovery behavior of the articular cartilage. Using previously validated biphasic creep indentation methodology, aggregate modulus, Poisson's ratio, permeability, shear modulus, thickness, creep and recovery equilibrium times and percent recovery were obtained at each site. Results were analyzed using ANOVA and multiple comparisons of the means (P<0.05).Results: Cartilage intrinsic material properties and thickness demonstrated significant differences between MPA and diluent treated joints. Diluent treated cartilage had a 97% increase in compressive stiffness modulus (P=0.0001) was 121% more permeable (P=0.0001), had 88% increase in shear modulus (P=0.0001), and was 24% thicker (P=0.0001) than MPA treated articular cartilage.Conclusions: The findings indicate that repetitive intra-articular administration of MPA to exercising horses alters the mechanical integrity of articular cartilage, which could lead to early cartilage degeneration

Fechamento parcial do anel inguinal externo em eqüinos: avaliação pós-operatória e influência na morfologia testicular Partial closure of the equine external inguinal ring: post-operatory evaluation and influence on testicular morphology

Avaliou-se a influência do fechamento parcial do anel inguinal externo (AIE) na morfologia testicular e caracterizaram-se as alterações pós-operatórias decorrentes de sua utilização em seis eqüinos machos. Sob anestesia geral, criou-se um acesso à cavidade vaginal que foi seguido de síntese da túnica vaginal parietal e sutura do AIE ipsilateral em aproximadamente 75% de seu diâmetro (antímero suturado). No antímero contralateral foi realizado procedimento cirúrgico semelhante, mas a sutura do anel inguinal foi removida imediatamente após sua aplicação (antímero controle). No pós-operatório, os animais foram examinados diariamente por quatro semanas. O trauma cirúrgico acarretou degeneração testicular no período pós-operatório e o acesso à cavidade vaginal predispôs à formação de aderências testiculares. O grau de degeneração testicular foi equivalente nos dois antímeros, suturado e controle, e nenhum dos testículos apresentou degeneração. O procedimento mostrou ser uma alternativa viável para o tratamento de hérnias inguinais quando se deseja evitar a orquiectomia.<br>In order to evaluate the influence of parcial closure of the external inguinal ring on testicular morphology and to characterize the local post-operatory changes, six adult horses were submitted to surgery under general anesthesia. The vaginal cavity was opened and approximately 75% of the external inguinal ring was sutured (sutured side). The same procedure was performed on the contralateral side, and the sutures of the external inguinal ring were immediately removed (sham side). The horses were examined daily for four weeks. The surgical procedure induced testicular degeneration and adhesion of the testis to the parietal vaginal tunic. Similar levels of testicular degeneration were detected in both sides (sutured and sham), and none of the testes evaluated had severe degeneration. This procedure can be used for the treatment of inguinal herniation as an alternative to castration and complete closure of the external inguinal ring