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Proximal Oblique Sliding Closing Wedge Osteotomy for Hallux Valgus
(2013)
WAGNER HITSCHFFELD, EMILIO
;
Cristián Ortiz
;
John S. Gould
;
Sameer Naranje
;
Pablo Wagner
<jats:sec><jats:title>Background:</jats:title><jats:p> The proximal oblique sliding closing wedge osteotomy (POSCOW) technique was developed to address moderate to severe hallux valgus deformity. We present a retrospective multicenter study to analyze the midterm radiological and clinical outcomes of patients treated with this type of proximal osteotomy fixed with plates. </jats:p></jats:sec><jats:sec><jats:title>Materials and Methods:</jats:title><jats:p> One hundred and forty-four patients (187 feet) were operated on between May 2005 and June 2010 in 2 separate centers. Inclusion criteria were symptomatic moderate to severe incongruent hallux valgus deformity, no significant restriction in the first metatarsophalangeal joint movement, none to minimal degenerative changes in the first metatarsophalangeal or the tarsometatarsal joints, and no hypermobility. The median age was 60 years. The preoperative hallux valgus angle (HV) was 35.6 degrees, intermetatarsal angle (IM) was 15.3 degrees, AOFAS score was 53 points. The median follow-up was 35 months (range, 12-73). A POSCOW osteotomy was performed in all patients and fixed with plates. We recorded the satisfaction rate, postoperative clinical and radiological results, and complications. </jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p> The patient satisfaction rate was 87%. The mean postoperative HV angle was 12.3 degrees, IM angle 4.8 degrees, AOFAS score 89 points. The mean decrease in the first metatarsal length was 2.2 mm (range, 0-8). Twelve feet (6.4%) with recurrence of the deformity required revision surgeries. Removal of complete or partial hardware was needed in 23 feet (12.3%) for symptomatic hardware. Five feet (2.6%) developed hallux varus but only 2 required surgery. Transfer metatarsalgia was noted in 9 feet (4.8%). </jats:p></jats:sec><jats:sec><jats:title>Conclusions:</jats:title><jats:p> The POSCOW osteotomy was an effective and reliable method for relieving pain and improving function. A learning curve was present, as most of the complications happened in the initial cases. To our knowledge, this is the largest reported series of proximal closing wedge osteotomy for hallux valgus deformities. </jats:p></jats:sec><jats:sec><jats:title>Level of Evidence:</jats:title><jats:p> Level IV, case series. </jats:p></jats:sec>
36Scopus© Citations 24
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Intraarticular Administration of Dexamethasone after Mesenchymal Stem Cells Implantation Does Not Improve Significantly the Treatment of Preestablished Full-Thickness Chondral Defect in a Rabbit Model
(2013)
Maximiliano Espinosa
;
Alex Vaisman
;
Nicolas Nazal
;
FIGUEROA POBLETE, DAVID HUMBERTO
;
Marcela Gallegos
<jats:sec><jats:title>Objective:</jats:title><jats:p> The aim of this study was to evaluate the contribution to hyaline cartilage regeneration of dexamethasone intraarticular administration after autologous mesenchymal stem cells (MSCs) implantation into a preestablished knee full-thickness chondral defect. </jats:p></jats:sec><jats:sec><jats:title>Design:</jats:title><jats:p> Full-thickness chondral defects of 4.5 × 4.5 mm<jats:sup>2</jats:sup> were surgically made in both medial femoral condyles of adult male New Zealand rabbits. Two weeks later, autologous ex vivo expanded bone marrow–derived MSCs were embedded in hyaluronic acid and implanted into the chondral defects. Immediately and every week after the intervention, dexamethasone 0.25 mg/kg was intraarticularly administered (MSC/dexa-treated group). Six weeks after MSC transplantation, the animals were euthanized and condyles were characterized molecularly according to aggrecan, collagen type II, and collagen type I gene expression (quantitative reverse transcriptase-polymerase chain reaction) and histologically (hematoxylin–eosin staining). Data of MSC/dexa-treated condyles were compared with untreated, dexa-treated, MSC-treated, or normal unlesioned condyles. </jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p> The ratio between collagen type II expression versus collagen type I expression in MSC/dexa-treated condyles was higher than one, even though the group mean value was not statistically different from that of untreated defects. Histological changes were observed between MSC/dexa-treated and untreated defects mainly in surface regularity and in hyaline matrix abundance. However, International Cartilage Repair Society score analysis did not support robust differences between those groups. </jats:p></jats:sec><jats:sec><jats:title>Conclusion:</jats:title><jats:p> Intraarticular administration of dexamethasone after autologous MSC implantation into a preestablished full-thickness chondral defect does not contribute significantly to the regeneration of a tissue with molecular and histological characteristics identical to hyaline cartilage. </jats:p></jats:sec>
1Scopus© Citations 5
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Simultaneous medial unicompartmental knee replacement and anterior cruciate ligament reconstruction: a narrative review and technical note
(2023)
Luca Macchiarola
;
Maximiliano Espinosa
;
Massimo Pirone
;
Gian Andrea Lucidi
;
Ilaria Cucurnia
Scopus© Citations 1 9
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Treatment of Meniscal Deficiency with Meniscal Allograft Transplantation and Femoral Osteotomy in a Patient with History of Lateral Discoid Meniscus
(2020)
Stefano Zaffagnini
;
Maximiliano Espinosa
;
Maria Pia Neri
;
Maurilio Marcacci
;
Alberto Grassi
20Scopus© Citations 7
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Anterior cruciate ligament regeneration using mesenchymal stem cells and collagen type I scaffold in a rabbit model
(2014)
David Figueroa
;
Maximiliano Espinosa
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CALVO RODRIGUEZ, RAFAEL
;
Maximiliano Scheu
;
Alex Vaisman
26Scopus© Citations 30
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Dexamethasone and rosiglitazone are sufficient and necessary for producing functional adipocytes from mesenchymal stem cells
(2015)
CONTADOR MARTINEZ, DAVID ERNESTO
;
EZQUER, EDUARDO FERNANDO
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Maximiliano Espinosa
;
Martha Arango-Rodriguez
;
Carlos Puebla
<jats:p> The final product of adipogenesis is a functional adipocyte. This mature cell acquires the necessary machinery for lipid metabolism, loses its proliferation potential, increases its insulin sensitivity, and secretes adipokines. Multipotent mesechymal stromal cells have been recognized as a source of adipocytes both in vivo and in vitro. The in vitro adipogenic differentiation of human MSC (hMSC) has been induced up to now by using a complex stimulus which includes dexamethasone, 3-isobutyl-1-methylxanthine, indomethacin, and insulin (a classical cocktail) and evaluated according to morphological changes. The present work was aimed at demonstrating that the simultaneous activation of dexamethasone’s canonical signaling pathways, through the glucocorticoid receptor and CCAAT-enhancer-binding proteins ( C/EBPs) and rosiglitazone through peroxisome proliferator-activated receptor gamma ( PPAR-gamma) is sufficient yet necessary for inducing hMSC adipogenic differentiation. It was also ascertained that hMSC exposed just to dexamethasone and rosiglitazone (D&R) differentiated into cells which accumulated neutral lipid droplets, expressed C/EBP-alpha, PPAR-gamma, aP2, lipoprotein lipase, acyl-CoA synthetase, phosphoenolpyruvate carboxykinase, adiponectin, and leptin genes but did not proliferate. Glucose uptake was dose dependent on insulin stimulus and high levels of adipokines were secreted (i.e. displaying not only the morphology but also expressing mature adipocytes’ specific genes and functional characteristics). This work has demonstrated that (i) the activating C/EBPs and PPAR-gamma signaling pathways were sufficient to induce adipogenic differentiation from hMSC, (ii) D&R producing functional adipocytes from hMSC, (iii) D&R induce adipogenic differentiation from mammalian MSC (including those which are refractory to classical adipogenic differentiation stimuli). D&R would thus seem to be a useful tool for MSC characterization, studying adipogenesis pathways and producing functional adipocytes. </jats:p>
1 1Scopus© Citations 57
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Assessment of Cell Viability of Fresh Osteochondral Allografts in N-Acetylcysteine-Enriched Medium
(2020)
CALVO RODRIGUEZ, RAFAEL
;
Maximiliano Espinosa
;
David Figueroa
;
Luz María Pozo
;
CONGET MOLINA, PAULETTE ANDREA
<jats:sec><jats:title>Objective</jats:title><jats:p> The purpose of this study was to evaluate the effect of N-acetylcysteine (NAC)-enriched storage medium on fresh osteochondral viability at 4°C. Our hypothesis was that the cell viability of chondrocytes obtained from human osteochondral tissue and stored at 4°C significantly improves in the presence of NAC. </jats:p></jats:sec><jats:sec><jats:title>Design</jats:title><jats:p> Controlled laboratory study. For this study, 8 samples of femoral condyle osteochondral tissue were obtained from patients undergoing total knee replacement. The samples were stored at either 4°C in phosphate-buffered saline (PBS) or at 3 different concentrations of NAC (NAC 1, 2, and 5 mM). Cell viability was analyzed at time 0 and 4 weeks by flow cytometry. The results of cell viability (median) were analyzed statistically using analysis of variance and Tukey’s post hoc test. P values <0.05 were considered statistically significant. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> The viability at time 0 was 95.5% ± 3.7%. At 4 weeks, the cell viability was 56.8% ± 20.1% in the control group (PBS), 83.8% ± 11.9% in the group stored with NAC 1 mM, 73.4% ± 13.6% in the group stored with NAC 2 mM, and 66.4% ± 27.7% in the group stored with NAC 5 mM. A statistically significant difference from the baseline viability (time 0) was observed in the PBS control group ( P = 0.0018) but not in the other groups. A statistically significant difference was observed in the NAC 1 mM group compared with the PBS group ( P = 0.0255). </jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p> The use of NAC at 1 mM concentration improves cell viability after 4 weeks of storage in chondrocytes obtained from human osteochondral tissue. </jats:p></jats:sec>
1 1Scopus© Citations 11

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