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Dive into the research topics where Efstathios Chronopoulos is active.

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Featured researches published by Efstathios Chronopoulos.


Orthopaedics & Traumatology-surgery & Research | 2013

Subchondral cyst development and MMP-1 expression during progression of osteoarthritis: An immunohistochemical study

A. Kaspiris; Lubna Khaldi; T.B. Grivas; E. Vasiliadis; I. Kouvaras; S. Dagkas; Efstathios Chronopoulos; Evangelia Papadimitriou

BACKGROUND Subchondral bone cyst (SBC) formation is often identified in patients with osteoarthritis. Furthermore, several studies have shown that expression of matrix metalloproteinases (MMPs) is elevated in patients with OA. OBJECTIVES The aim of our study is to correlate the presence of SBCs and MMP-1 expression with the osteochondral alterations during OA progression. METHODS We studied the cartilage and subchondral bone of 15 patients who had undergone total knee or hip replacement due to primary OA. As controls, we used the femoral heads of three patients without macroscopic OA changes. We evaluated three specimens per patient. RESULTS Specimens were divided in four groups based on the Mankin histological severity score. Using immunohistochemistry, we noted SBCs at the site of greatest disease severity. Specifically, these were present more frequently in group III (Mankin score: 6-7) and IV (Mankin: ≥ 8), compared with group I (Mankin: 1-3) and II (Mankin: 4-5). Mild OA stages (Mankin: 1-6) were characterized by degeneration and thinning of the cartilage, followed by increased osteoblast and osteoclast activity of the subjacent bone and the subsequent appearance of SBCs. Simultaneously, we observed expression of MMP-1 in groups I and II in the cartilage and III and IV in both the cartilage and the subchondral bone. Moreover, osteoblast-like cells in the lining of the SBCs showed an increased expression of MMP-1 in stages III and IV. CONCLUSION Our study provides immunohistological evidence that SBCs accumulate in advanced OA and contain activated cells, which express MMP-1, suggesting that they may thus participate in the osteochondral changes of OA. LEVEL OF EVIDENCE Level III; prospective comparative study.


Gait & Posture | 2013

EMG activation of trunk and upper limb muscles following experimentally-induced overpronation and oversupination of the feet in quiet standing

Theodoros Ntousis; Dimitris Mandalidis; Efstathios Chronopoulos; Spyros Athanasopoulos

Kinematic studies have shown that experimentally-induced overpronation or oversupination of the subtalar joint may alter the position of the legs, hips and pelvis and consequently the trunk and upper limb. The purpose of the present study was to examine whether such foot deformity affects the activity of muscles that act on the trunk and upper limb. Twenty-eight healthy individuals (11 males and 17 females) 21.4±1.9 years of age without skeletal deformity, leg length discrepancy (LLD), overpronated or oversupinated feet or excessive lateral pelvic inclination volunteered for the study. Bilateral EMG recordings of the latissimus dorsi, pectoralis major and rectus abdominis were undertaken for 30-s with each subject in the relaxed standing position and at 5° and 10° bilateral or unilateral overpronation or oversupination of the foot on the dominant side using wooden wedge-shape blocks. The recorded EMG activity was normalised based on the EMG activity produced by the muscles under investigation during maximum isometric voluntary contraction. The findings of the present study revealed that neither bilateral nor unilateral overpronation/oversupination of the feet induced a significant alteration of the EMG activity of the latissimus dorsi, pectoralis major and rectus abdominis on either the dominant or non-dominant side. These findings suggest that in the absence of other major structural deformity bilateral or unilateral foot overpronation or oversupination does not affect the EMG activity of muscles that act on the trunk and upper limb in quiet standing.


European Journal of Orthopaedic Surgery and Traumatology | 2014

Currents of plate osteosynthesis in osteoporotic bone

Kalliopi Lampropoulou-Adamidou; Panagiotis K. Karampinas; Efstathios Chronopoulos; John Vlamis; Demetrios S. Korres

Osteoporotic fractures are becoming more prevalent with ageing of populations worldwide. Inadequate fixation or prolonged immobilization after non-surgical care leads to serious life-threatening events, poor functional results and lifelong disability. Thus, a stable internal fixation and rapid initiation of rehabilitation are required for faster return of function. Conventional internal fixation attempts to achieve the exact anatomy, often with extended soft-tissue stripping and compression of the periosteum, causing disturbance of the metaphyseal and comminuted fracture’s bone blood supply. This technique relies on frictional forces between bone and plate. Osteoporotic bone might not be able to generate enough torque with the screw to securely fix the plate to bone. Thus, this surgical management have resulted in increased incidence of poor results in elderly, osteoporotic patients. The newly developed locked internal fixators, locking compression plates and less invasive stabilization system, consist of plate and screw systems where the screws are locked in the plate, minimizing the compressive forces exerted between plate and bone. Thus, the plate does not need to compress the bone nor requires precise anatomical contouring of a plate disturbing the periosteal blood supply. These fixators allowed the development of the minimal invasive percutaneous osteosynthesis. Nowadays, locking plates are the fixation method of choice for osteoporotic, diaphyseal or metaphyseal, severely comminuted fractures.


Pathophysiology | 2015

Macrophage-specific metalloelastase (MMP-12) immunoexpression in the osteochondral unit in osteoarthritis correlates with BMI and disease severity

Angelos Kaspiris; Lubna Khaldi; Efstathios Chronopoulos; Elias Vasiliadis; Theodoros B Grivas; Ioannis Kouvaras; Spyridon Dagkas; Evangelia Papadimitriou

BACKGROUND Metalloproteinase 12 (MMP-12) is induced in chondrocytes during fetal development and malignant transformation. OBJECTIVES The aim of our study is to examine the expression of MMP-12 in the cartilage and the subchondral bone of patients with osteoarthritis (OA) and to correlate its expression with disease severity and anthropometric characteristics. METHODS Overall, 60 sections from 20 patients with idiopathic OA, were examined for the immunolocalization of MMP-12. As controls, we used the femoral heads of 4 patients treated with seniarthroplasty after fracture. Demographic characteristics and Body Mass Index (BMI) were calculated for all subjects. RESULTS Specimens were divided into four groups based on the Mankin histological severity score. The immunohistochemical study showed MMP-12 expression in the cartilage and subchonral bone of OA patients, while there was no expression in normal controls. At the moderate OA changes (Mankin score: 6-7), MMP-12 was detected mainly at the matrix of fibrocartilage tissue. During disease progression, MMP-12 was expressed at the sides of the cartilage and bone erosion and in the bone cysts. Furthermore, it was traced in the osteocytes of the subchondral bone. Osteoblast-like cells and bone lining cells express MMP-12 during the stage of severe OA (Mankin: ≥8). Osteoclasts expressing MMP-12 were also detected in the group of severe OA. Interestingly, MMP-12 expression was positively correlated with the age and the BMI of OA patients. CONCLUSION The increased expression of MMP-12 in the bone-cartilage unit of OA patients suggests a possible role in OA pathogenesis and progression. LEVEL OF EVIDENCE III, prospective comparative study.


World Neurosurgery | 2017

Charles Estienne (1504–1564): His Life, Work, and Contribution to Anatomy and the First Description of the Canal in the Spinal Cord

Konstantinos Markatos; Demetrios Chytas; Demetrios S. Korres; Konstantinos Laios; Georgios Androutsos; Efstathios Chronopoulos

The purpose of this historic review is to summarize the life, work, and contribution to anatomy of Charles Estienne (also known by the Latin name Carolus Stephanus). Charles Estienne was an early exponent of the science of anatomy in France. Although he remained under the influence of the Galenic tradition of medicine, anatomy, and surgery throughout his distinguished career, he had a significant influence on the scientific revolution and anatomy reformation of the 16th century. Nevertheless, he cannot be placed at the same level of contribution as Vesalius, because of his lack of discipline in his work, hesitation to diverge totally from traditional beliefs, and his hesitation for a total criticism of the Galenic tradition.


Cytokine | 2016

Effects of mechanical loading on the expression of pleiotrophin and its receptor protein tyrosine phosphatase beta/zeta in a rat spinal deformity model.

Angelos Kaspiris; Efstathios Chronopoulos; Theodoros B Grivas; Elias Vasiliadis; Lubna Khaldi; Margarita Lamprou; Pavlos Lelovas; Nikolaos Papaioannou; Ismene Dontas; Evangelia Papadimitriou

Mechanical loading of the spine is a major causative factor of degenerative changes and causes molecular and structural changes in the intervertebral disc (IVD) and the vertebrae end plate (EP). Pleiotrophin (PTN) is a growth factor with a putative role in bone remodeling through its receptor protein tyrosine phosphatase beta/zeta (RPTPβ/ζ). The present study investigates the effects of strain on PTN and RPTPβ/ζ protein expression in vivo. Tails of eight weeks old Sprague-Dawley rats were subjected to mechanical loading using a mini Ilizarov external apparatus. Rat tails untreated (control) or after 0 degrees of compression and 10°, 30° and 50° of angulation (groups 0, I, II and III respectively) were studied. PTN and RPTPβ/ζ expression were evaluated using immunohistochemistry and Western blot analysis. In the control group, PTN was mostly expressed by the EP hypertrophic chondrocytes. In groups 0 to II, PTN expression was increased in the chondrocytes of hypertrophic and proliferating zones, as well as in osteocytes and osteoblast-like cells of the ossification zone. In group III, only limited PTN expression was observed in osteocytes. RPTPβ/ζ expression was increased mainly in group 0, but also in group I, in all types of cells. Low intensity RPTPβ/ζ immunostaining was observed in groups II and III. Collectively, PTN and RPTPβ/ζ are expressed in spinal deformities caused by mechanical loading, and their expression depends on the type and severity of the applied strain.


Cartilage | 2018

Platelet-Rich Plasma versus Corticosteroid Intra-Articular Injections for the Treatment of Trapeziometacarpal Arthritis: A Prospective Randomized Controlled Clinical Trial

Michael-Alexander Malahias; Leonidas Roumeliotis; Vasileios S. Nikolaou; Efstathios Chronopoulos; Ioannis Sourlas; Georgios C. Babis

Various systematic reviews have recently shown that intra-articular platelet-rich plasma (IA-PRP) can lead to symptomatic relief of knee osteoarthritis for up to 12 months. There exist limited data on its use in small joints, such as the trapeziometacarpal joint (TMJ) or carpometacarpal joint (CMCJ) of the thumb. A prospective, randomized, blind, controlled, clinical trial of 33 patients with clinical and radiographic osteoarthritis of the TMJ (grades: I-III according to the Eaton and Littler classification) was conducted. Group A patients (16 patients) received 2 ultrasound-guided IA-PRP injections, while group B patients (17 patients) received 2 ultrasound-guided intra-articular methylprednisolone and lidocaine injections at a 2-week interval. Patients were evaluated prior to and at 3 and 12 months after the second injection using the visual analogue scale (VAS) 100/100, shortened Disabilities of the Arm, Shoulder, and Hand Questionnaire (Q-DASH), and patient’s subjective satisfaction. No significant differences between the baseline clinical and demographic characteristics of the 2 groups were identified. After 12 months’ follow-up, the IA-PRP treatment has yielded significantly better results in comparison with the corticosteroids, in terms of VAS score (P = 0.015), Q-DASH score (P = 0.025), and patients’ satisfaction (P = 0.002). Corticosteroids offer short-term relief of symptoms, but IA-PRP might achieve a lasting effect of up to 12 months in the treatment of early to moderate symptomatic TMJ arthritis.


Osteoporosis International | 2017

Response to: A role for thiazide diuretic therapy in preventing bone loss, fracture and nephrolithiasis in individuals with thalassemia and hypercalciuria?

Anastasia D. Dede; G. Trovas; Efstathios Chronopoulos; Ioannis K. Triantafyllopoulos; Ismini Dontas; Nikolaos Papaioannou; Symeon Tournis

Dear Editor, We would like to thank AdamMorton for his interesting comments on the possible value of thiazide diuretics in the management of bone loss, fractures, and nephrolithiasis in patients with thalassemia and calciuria [1, 2]. We agree with the comments, however, to our knowledge, there are no studies evaluating the effects of thiazide diuretics on these outcomes in patients with thalassemia. Thiazides have documented protective effect on nephrolithiasis [3] and indeed have been associated with positive effects on bone mineral density [4, 5] even though the effects are small and not invariably demonstrated [6]. Fracture data are based only on observational studies and are inconclusive showing potential beneficial [7] or negative effects [8], possibly depending on age. Recently, a Cochrane review has shown an overall reduction in the risk of hip fractures [9]. Due to the complex pathophysiology of thalassemia, welldesigned studies evaluating the effects of thiazide diuretics on calciuria, nephrolithiasis, and bone mineral density and aiming to identify subsets of patients who might benefit from such an intervention would be valuable.


Medical Science Case Reports | 2017

Volar Trans-Scaphoid Perilunate Dislocation of the Wrist: A Case Report

Andreas Panagopoulos; Dimitrios Bougiouklis; George Prelorentzos; Panagiotis Grigoropoulos; Zinon T. Kokkalis; Efstathios Chronopoulos

Background: Palmar perilunate fracture-dislocations in which the lunate remains in its normal position when the other carpal bones dislocate towards the volar aspect of the wrist accounts for less than 3% of perilunate dislocations. Case Report: A 24-year-old motorcyclist was admitted to our Department after having been involved in a traffic accident in which he had landed with his outstretched right hand on the road surface. X-rays revealed a volar trans-scaphoid perilunate dislocation of the carpus. Because closed reduction initially failed, the patient was transferred immediately to the operating theater for open reduction and fixation. Through a volar approach the median nerve was decompressed, the scaphoid was fixed with a cannulated screw, and the volar capsular-ligamentous complex was repaired with interrupted sutures. The carpus was relocated and stabilized with 2 K-wires through a dorsal approach. At 2-year follow-up, he had good range of motion and grip strength and demonstrated a Mayo wrist score of 86 points. Conclusions: Volar trans-scaphoid perilunate carpal dislocations are rare injuries and can be initially missed if not properly assessed. Early management with anatomical fixation using both volar and dorsal approaches can provide an excellent clinical outcome.


Children today | 2016

Perinatal Risk Factors and Genu Valgum Conducive to the Onset of Growing Pains in Early Childhood

Angelos Kaspiris; Efstathios Chronopoulos; Elias Vasiliadis

The most prevalent musculoskeletal disorder of childhood with unclear aetiology is growing pains (GPs). Anatomic deformities and factors that change bone turnover are implicated in GP pathophysiology. Perinatal risk factors alter the bone metabolism affecting the bone mineral density and content. The aim of our study was to analyze the relationship between GPs, knock knees and perinatal factors. The examined population consisted of 276 children aged 3–7 years. Among them, ten pairs of dizygotic twins were evaluated. The data were collected by using a combination of semi-structured questionnaires, clinical examinations and medical charts of the children and the obstetric history of the mothers. A total of 78 children presenting GPs met Peterson’s criteria. Genu valgum severity was a significant factor for GP manifestation and for their increased frequency and intensity. Subsequently, perinatal factors regarding gestational age, Apgar score, head circumference (lower than 33 cm) and birth length or weight (smaller than 50 cm and 3000 g, respectively) made a remarkable contribution to the development of GPs. Conversely, antenatal corticosteroid treatment, increased maternal age and maternal smoking during pregnancy were not predictive of the disorder. Our data are potentially supportive for the “bone strength” theory and for the contribution of anatomical disturbances in GP appearance.

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Lubna Khaldi

National and Kapodistrian University of Athens

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Nikolaos Papaioannou

National and Kapodistrian University of Athens

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Ioannis K. Triantafyllopoulos

National and Kapodistrian University of Athens

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Ioannis Sourlas

National and Kapodistrian University of Athens

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Anastasia D. Dede

National and Kapodistrian University of Athens

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Demetrios S. Korres

National and Kapodistrian University of Athens

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Dimitris Mandalidis

National and Kapodistrian University of Athens

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Elias Vasiliadis

Boston Children's Hospital

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