Advertisement for orthosearch.org.uk
Results 1 - 10 of 10
Results per page:
Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 9 - 9
1 Apr 2018
Garcia-Rey E Carbonell R Cordero J Gomez-Barrena E
Full Access

Introduction

Durable bone fixation of uncemented porous-coated acetabular cups can be observed at a long-term, however, polyethylene (PE) wear and osteolysis may affect survivorship. Accurate wear measurements correlated with clinical data may offer unique research information of clinical interest about this highly debated issue.

Objetive

We assessed the clinical and radiological outcome of a single uncemented total hip replacement (THR) system after twenty years analysing polyethylene wear and the appearance of osteolysis.


Bone & Joint Research
Vol. 6, Issue 5 | Pages 315 - 322
1 May 2017
Martinez-Perez M Perez-Jorge C Lozano D Portal-Nuñez S Perez-Tanoira R Conde A Arenas MA Hernandez-Lopez JM de Damborenea JJ Gomez-Barrena E Esbrit P Esteban J

Objectives

Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the ‘race for the surface’ theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied.

Methods

We describe a method for the study of bacterial adherence in the presence of preosteoblastic cells. For this purpose we mixed different concentrations of bacterial cells from collection and clinical strains of staphylococci isolated from implant-related infections with preosteoblastic cells, and analysed the minimal concentration of bacteria able to colonise the surface of the material with image analysis.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_8 | Pages 39 - 39
1 Apr 2017
Gomez-Barrena E Rosset P Hernigou P Gebhard F Ehrnthaller C Baldini N Layrolle P
Full Access

Background

Definitive proof is lacking on mesenchymal stem cell (MSCs) cellular therapy to regenerate bone if biological potential is insufficient. High number of MSCs after GMP expansion may solve the progenitor insufficiency at the injury but clinical trials are pending.

Methods

A prospective, multicenter, multinational Phase I/IIa interventional clinical trial was designed under the EU-FP7 REBORNE Project to evaluate safety and early efficacy of autologous expanded MSCs loaded on biomaterial at the fracture site in diaphyseal and/or metaphysodiaphyseal fractures (femur, tibia, humerus) nonunions. The trial included 30 recruited patients among 5 European centres in France, Spain, Germany, and Italy. Safety endpoints (local and general complication rate) and secondary endpoints for early efficacy (number of patients with clinically and radiologically proven bone healing at 12 and 24 weeks) were established. Cultured MSCs from autologous bone marrow, expanded under GMP protocol was the Investigational Medicinal Product, standardised in the participating countries confirming equivalent cell production in all the contributing GMP facilities. Cells were mixed with CE-marked biphasic calcium phosphate biomaterial in the surgical setting, at an implanted dose of 20−106 cells per cc of biomaterial (total 10cc per case) in a single administration, after debridement of the nonunion.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 130 - 130
1 Feb 2017
Garcia-Rey E Cimbrelo EG Gomez-Barrena E
Full Access

Background and aim

Despite good survivorship analysis for most uncemented tapered straight stems, new proposals modifying stem design in total hip replacement (THR) are being introduced in order to facilitate femoral revision surgery.

We have evaluated the clinical and radiological results of four different designs of uncemented tapered straight stems implanted in our institution in order to assess: operative complications, clinical results, survivorship analysis for aseptic loosening and radiographic findings

Methods

1008 hips implanted from 1998 to 2006 were prospectively followed for a mean of 12 years (range, 10 to 17). Four uncemented femoral designs employing a tapered straight stem were included: 209 Alloclassic stems, 420 Cerafit, 220 SL-Plus and 159 Summit. All hips had a 28 or 32 mm femoral head, and polyethylene (PE)-on metal or ceramic-on-ceramic bearing surface. Radiological femoral type, stem position, femoral canal filling at three levels and the possible appearance of loosening and other bone remodelling changes were recorded in all hips.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 33 - 33
1 Jul 2014
Perez-Jorge C Perez-Tanoira R Lozano D Conde A Arenas M Hernandez-Lopez J De-Damborenea J Gomez-Barrena E Esbrit P Esteban J
Full Access

Summary Statement

Description of an original in vitro protocol for assessing combined bacteria and cell competitive adherence on the surface of biomaterials of medical interest

Objectives

Biomaterial-related infections are a major clinical problem. The pathogenesis of this syndrome has been described as a competitive adherence between bacteria and human cells in the so-called “race for the surface” theory. The aim of this study is to develop an in vitro protocol method that can be used to investigate this competence and its implications in the development of materials aimed to be used in orthopedic surgery.


Bone & Joint Research
Vol. 3, Issue 3 | Pages 48 - 50
1 Mar 2014
Lidgren L Gomez-Barrena E N. Duda G Puhl W Carr A


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XL | Pages 144 - 144
1 Sep 2012
Perez-Jorge C Perez-Tanoira R Arenas M Matykina E Conde A Gomez-Barrena E
Full Access

INTRODUCTION

Biomaterial-related infections are an important complication in orthopaedic surgery [1], and Staphylococcus sp. accounts for more than half of the prosthetic joint infection cases [2]. Adhesion of bacteria to biomaterial surfaces is a key step in pathogenesis of such infections [3]. Titanium alloys are widely used in orthopaedic implants because their biocompatibility [4]. Surface incorporation of ions with antimicrobial properties, like fluorine, is one strategy previously studied with good results [5].

MATERIAL AND METHODS

A 18mm diameter rod of Ti–6Al–4V alloy ELI grade according to the standard ASTMF136-02 supplied by SURGIVAL was cut into 2 mm thick disk specimens, ground through successive grades of SiC paper to 1200 grade, degreased with a conventional detergent and rinsed in tap water followed by deionised water. The specimens were then chemically polished (CP).

The disks were anodized only on one side by using a two electrode cell in a suitable electrolyte. TiO2 barrier layers, without fluoride (BL), were produced by anodizing in 1 M H2SO4 at 15 mA cm-2 to 90 V, reaching 200 nm of thickness.

Fluoride barrier layers (FBL) were produced in an electrolyte containing 1 M NH4H2PO4 and 0.15 M NH4F, at constant voltage controlled at 20 V for 120 min at 20°C; the thickness of the layer is 140 nm.

Laboratory biofilm-forming strains of Staphylococcus aureus 15981 [6] and Staphylococcus epidermidis ATCC 35984 were used in adherence studies, which were performed using the protocol by Kinnari et al [7]. Photographs obtained were studied by ImageJ software. Statistical analysis was performed by EPI-INFO software. The experiments were performed in triplicates


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 455 - 455
1 Sep 2009
Esteban J Molina-Manso D Martín-de-Hijas N García-Almeida D Fernández-Roblas R Cordero J Gomez-Barrena E
Full Access

Biofilm development is a major factor in the pathogenesis of implant-related infections. However, there are only a low number of studies that analyses the ability of clinical isolates of bacteria to develop biofilm in vitro. Here we study biofilm development in several strains of Staphylococcus aureus and Coagulase-negative Staphylococcus (CNS) consecutively isolated from retrieved orthopaedic implants from patients diagnosed of implant-related infections.

We have evaluated in vitro biofilm development using the crystal violet technique in microtiter plates. Biofilm development was confirmed by visual microscopy and Confocal Laser Scanning Microscopy. Staphylococcal strains were isolated from implant-related infections by sonication of retrieved prosthesis as previously published by our group, and identified using conventional methods.

Twenty-seven strains (15 S. aureus, nine S. epidermidis, and one each of S. hominis, S. lugdunensis and S. warneri) were included in the study. Four strains of S. aureus (26.7 %) and one strain of S. epidermidis (8.3 %) did not develop biofilm in the test, showing OD lectures almost identical to the negative control. No statistical differences were detected between the two groups. The microscopic examination confirms this finding. Among the biofilm-producing strains, an important difference of the amount of biofilm produced was detected. One strain (S. aureus) produced biofilm in greater amount than all other strains, detectable even by visual examination of the plate.

In conclusion, not all staphylococcal strains isolated from implant-related infections are able to develop biofilm in vitro. There must be other pathogenic factors that are important in the pathogenesis of implant-related infections and need to be studied in order to develop a better strategy for treat these infections.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_III | Pages 457 - 457
1 Sep 2009
Bonsfills N Foruria A Martín JG Ballesteros-Masso R Nuñez A Gomez-Barrena E
Full Access

Introduction: Anterior cruciate ligament (ACL) injury is the first cause of knee instability. There is not enough evidence for the best therapeutic option, as operative and non-operative treatments of anterior cruciate ligament (ACL) injuries are often associated with a lack of proprioception and a persistent muscle weakness of unclear origin.

Material and methods: This study in the cat experimentally compares in the long-term both neural and muscular activity in the knee articular nerves (PAN and MAN), quadriceps and hamstrings, in the chronic unstable knee and the reconstructed knee. Experimental section of ACL in twenty four cat’s knees was followed by stable reconstruction in six knees and unstable reconstruction in eight knees, leaving the other ten knees unstable without reconstruction. Electrical activity from muscles and nerves was registered with Ni-Cr electrodes. Mean firing activity and peristimulus time histograms (PSTH) for each structure were obtained. Secondly, it evaluates the neuromuscular response changes due to the graft’s mechanical competence, comparing stable and unstable reconstructed knees. Two different grafts were evaluated in the reconstructed knee, pediculated extensor digitorum longus and free bone-tendon-bone from patellar tendon. Statitiscal analysis consisted in Mann-Whitney’s test with Bonferroni adjustment between groups, and a two-way ANOVA to evaluate the separate effect of graft type and graft competence.

Results: We found an increased periarticular muscle activity during anterior tibial translation in chronically unstable knees. Both reconstructed and non-reconstructed unstable knees lose the fast reactive activity in the articular nerves. When stability was recovered after reconstruction, knees showed a more adjusted, although incomplete, muscular reaction. No differences were observed among grafts, but their mechanic competence was determinant in the neuromuscular firing activity.

Discussion: ACL injured knees in the cat, with or without reconstruction, display confirmed abnormalities in neuromuscular reaction in the long-term, while to regain stability with a competent graft in the reconstructed knee is crucial to lessen this anomalous reaction.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 95 - 95
1 Mar 2006
Bonsfills N Gomez-Barrena E Raygoza J Nuñez A
Full Access

Aims: The purpose of this study is to determine muscle fibre length around the knee before and after anterior cruciate ligament (ACL) transection, and to test its ability to detect instability changes.

Material and methods: Pairs of piezoelectric crystals were inserted in four periarticular muscles (vastus lateralis -VL-, vastus medialis -VM-, lateral hamstrings -LH-, medial hamstrings -MH-) around 11 knees from 8 cats. Distance between pairs was measured while performing 10 passive repetitions of anterior tibial displacement at 90 degrees and 30 degrees flexed knee, flexion and extension, and controlled by sagittal plane video recordings. Ultrasound signal between crystals in each pair was analysed to obtain intensity and time-dependent parameters. Data from control and unstable knees were statistically compared.

Results: Fibre lengthening was observed in the four studied muscles under anterior tibial traction. Significant increases in fibre length at VL, VM (p< 0,05) and LH (P< 0,01) were seen in unstable knees versus normal knees when anterior tibial traction was performed at 90 degrees knee flexion. Flexion and extension produced passive changes in fibre length (quadriceps lengthening and hamstrings shortening for flexion, the opposite for extension), but no significant variations were measured when the ACL was sectioned.

Discussion: Ultrasonomicrometry offers a new approach to comprehend anterior instability of the knee when studying periarticular muscle fibre length. Variations in the response are specific for the anterior tibial displacement in unstable knees. This technique can be used in combination with electromyography for a better understanding of muscle behaviour in ACL deficient knees.