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Abstracts / Foot and Ankle Surgery 23(S1) (2017) 1–28
collagenase with the most commonly used high-dose single injection and to controls. Methods: Forty-five (N = 45) rabbits were randomly divided into three groups (A, B and Control). Animals in Group A (n = 18) underwent three serial low-dose (0.1 mg) injections of bacterial type I collagenase in both Achilles tendons, separated by a two-week interval. Animals in Group B (n = 18) underwent bilateral single high dose injections (0.3 mg). Rabbits in Control Group (n = 9) were injected with three consecutive doses of saline solution. Animals were euthanized after 10, 12 and 16 weeks. Histological findings, using the Bonar tendinopathy score, and biomechanical properties were compared between the groups and inside each the group, in the different time-points of euthanasia. P-values <0.05 were considered significant. Results: After 16 weeks, the Bonar score was significantly increased for both Groups A (11.8 ± 2.28) and B (5.6 ± 2.51), when compared to controls (2 ± 0.76). Group A has also differed from Group B (p < 0.001). Regarding biomechanical findings, groups differed in cross-sectional area of the Achilles tendon (p = 0.003), Young’s modulus (p = 0.024), Yield stress (p = 0.020) and ultimate tensile strength (p = 0.022), with the worst results in animals from Group A. Conclusions: The animal model of Achilles tendinopathy induced by three consecutive injections of 0.1 mg collagenase demonstrated worse histological and biomechanical properties after 16 weeks, demonstrating a more progressive and long lasting tendinopathic findings, reproducing better the disease in humans. http://dx.doi.org/10.1016/j.fas.2017.07.1093 50 IFFAS S10 05 Therapeutic potential of mesenchymal stem cells to treat Achilles tendon injuries M.H. Costa Vieira ∗ , A.C.M.B.A. Silva, R.J. Oliveira, W.S. Fernandes, R. Antoniolli Silva Federal University of Mato Grosso do Sul, Brazil Rupture of the Achilles tendon diminishes quality of life. The gold-standard therapy is a surgical suture, but this presents complications, including wound formation and inflammation. These complications spurred evaluation of the therapeutic potential of mesenchymal stem cells (MSCs) from adipose tissue. New Zealand rabbits were divided into 6 groups (three treatments with two time points each) evaluated at either 14 or 28 days after surgery: cross section of the Achilles tendon (CSAT); CSAT + Suture; and CSAT + MSC. A comparison between all groups at both time points showed a statistically significant increase in capillaries and in the structural organization of collagen in the healed tendon in the CSAT + Suture and CSAT + MSC groups at the 14-day assessment. Comparison between the two time points within the same group showed a statistically significant decrease in the inflammatory process and an increase in the structural organization of collagen in the CSAT and CSAT + MSC groups. A study of the genomic integrity of the cells suggested a linear correlation between an increase of injuries and culture time. Thus, MSC transplantation is a good alternative for treatment of Achilles tendon ruptures because it may be conducted without surgery and tendon suture and, therefore, has no risk of adverse effects resulting from the surgical wound or inflammation caused by non absorbable sutures. Furthermore, this alternative treatment exhibits a better capacity for wound healing and maintaining the original tendon architecture, depending on the
arrangement of the collagen fibers, and has important therapeutic potential. http://dx.doi.org/10.1016/j.fas.2017.07.1094 51 IFFAS S11 01 Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome T. Nakasa ∗ , M. Sawa, Y. Ikuta, M. Yoshikawa, Y. Tsuyuguchi, N. Adachi Department of Orthopaedic Surgery, Hiroshima University, Japan Introduction: Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a medial OLT, the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial OLT and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT. Methods: Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. MRI images provided measurements for the attachment of the deep deltoid ligaments to the coronal sections. Also, the continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings in medial OLT. Results: Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet. Conclusions: The location of the deep deltoid ligament attachment to the medial OLT was more proximal and its fibers continued to the osteochondral fragment more than in non-medial OLT. http://dx.doi.org/10.1016/j.fas.2017.07.1095 52 IFFAS S11 02 Matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle is safe and effective M. Richter ∗ , S. Zech, S.A. Meissner Department for Foot and Ankle Surgery Nuremberg and Rummelsberg, Germany Background: The aim of the study was to assess the 5-yearfollow-up of matrix-associated stem cell transplantation (MAST) in chondral defects of the ankle. Methods: In a prospective consecutive non-controlled clinical follow-up study, all patients with chondral defect that were treated with MAST from April1 2009 to September 30, 2011 were analyzed. Size and location of the chondral defects and the Visual-AnalogueScale Foot and Ankle (VAS FA) before treatment and at follow-up were analysed. Stem cell-rich blood was harvested from the