Domínguez Pérez, Juan Manuel

To assess the biomechanical effects of intra-tendinous injections of PRGF on the healing Achilles tendon after repair in a sheep model. Thirty sheep were randomly assigned into one of the six groups depending on the type of treatment 10 received (PRGF or placebo) and survival time (2, 4 and 8 weeks). The Achilles tendon injury was repaired by suturing the tendinous edges employing a three-loop pulley pattern. A trans-articular external fixation system was then used for immobilization. The PRGF or placebo was administered on a weekly basis completing a maximum of 3 infiltrations. The force, section and tension values were compared between the operated and healthy Achilles tendons across all groups. The PRGF-treated tendons had higher force at eight weeks compared with the placebo group (p=0.007). Between two and four weeks, a significant increase in force in both the PRGF-treated tendon (p=0.0027) and placebo group (p=0.0095) occurred. No significant differences were found for section ratio between PRGF-treated tendons and the placebo group for any of the time periods evaluated. At 2 weeks PRGF-treated tendons had higher tension ratio compared to placebo group tendons (p=0.0143). Both PRGF and placebo treatments significantly improved the force (p<0.001 and p=0.0095, respectively) and tension (p=0.009 and p=0.0039, respectively) ratios at 8 compared to 2 weeks. The application of PRGF increases Achilles tendon repair strength at 8 weeks compared to the use of placebo. The use of PRGF does not modify section and tension ratios compared to placebo at 8 weeks. The tension ratio progressively increases between two and eight weeks compared with the placebo. PRGF can be used in the clinical setting as a complementary therapy to improve the repair strength of acute Achilles tendon ruptures.

The aim of this study was to evaluate the use of serum type II collagen cleavage epitope and serum hyaluronic acid as biomarkers for treatment monitoring in osteoarthritic dogs. For this purpose, a treatment model based on mesenchymal stem cells derived from adipose tissue combined with plasma rich in growth factors was used. This clinical study included 10 dogs with hip osteoarthritis. Both analytes were measured in serum at baseline, just before applying the treatment, and 1, 3, and 6 months after treatment. These results were compared with those obtained from force plate analysis using the same animals during the same study period. Levels of type II collagen cleavage epitope decreased and those of hyaluronic acid increased with clinical improvement objectively verified via force plate analysis, suggesting these two biomarkers could be effective as indicators of clinical development of joint disease in dogs.

Background: Subjective pain assessment scales have been widely used for assessing lameness in response to pain, but the accuracy of these scales has been questioned. To assess scale accuracy, 10 lame, presa Canario dogs with osteoarthritis (OA) associated with bilateral hip dysplasia were first treated with mesenchymal stem cells. Then, potential lameness improvement was analyzed using two pain scales (Bioarth and visual analog scale). These data were compared with similar data collected using a force platform with the same animals during a period of 6 months after treatment. Results: The F test for intraclass correlation showed that concordance in pain/lameness scores between the 2 measuring methodologies was not significant (P value ≥ 0.9213; 95 % confidence interval, –0.56, 0.11). Although subjective pain assessment showed improvement after 6 months, force platform data demonstrated those same animals had returned to the initial lameness state. Conclusion: Use of pain assessment scales to measure lameness associated with OA did not have great accuracy and concordance when compared with quantitative force platform gait analysis.