Manuel Gutierres

Behaviour of human osteoblastic cells cultured on plasma-sprayed titanium implants in the presence of nicotine.

OBJECTIVES The aim of this work was to analyse the behaviour of human bone marrow osteoblastic cells cultured on the surface of routinely used plasma-sprayed titanium implants in the presence of plasmatic and salivary nicotine levels reported in smokers. MATERIAL AND METHODS Human bone marrow cells (first subculture) were seeded on titanium implants and cultured for 35 days in alpha-minimal essential medium supplemented with 10% foetal bovine serum, 50 microg/ml ascorbic acid, 10 mM beta-glycerophosphate and 10 nM dexamethasone. Seeded implants were exposed to nicotine, 10-1 mg/ml, from days 1 to 35, and characterized for cell morphology, viability/proliferation, alkaline phosphatase (ALP) activity and matrix mineralization. RESULTS Low levels of nicotine, 10 and 50 ng/ml, representative of the plasma concentrations reported in smokers, did not cause significant effects in the cell behaviour, although a small induction in cell growth and functional activity appeared to occur. Higher nicotine levels, 0.01-1 mg/ml, within those attained in saliva through tobacco use, caused evident dose-dependent effects in osteoblastic cell behaviour, i.e., a stimulatory effect in cell growth, ALP activity and matrix mineralization, at concentrations up to 0.2 mg/ml, and a deleterious effect at higher levels. CONCLUSIONS Considering the high tissue diffusion potential of nicotine, the results suggest the possibility of a direct modulation of the osteoblast activity as a contributing factor to the overall effect of nicotine in the bone microenvironment around dental implants.

Biological Behaviour of Bonelike® Graft Implanted in the Tibia of Humans

This paper reports the ability of Bonelike® to regenerate bone defected areas when implanted in the tibia of 3 patients (average age of 59 years) during a high tibial osteotomy (HTO) to treat medial compartment osteoarthritis of the knee. Bonelike® is a synthetic bone graft designed to mimic the inorganic composition of bone using a patent process that consists of liquid sintering hydroxyapatite in the presence of CaO-P2O5 based glass. The preliminary clinical evaluation performed showed that an intimate contact between new formed bone and Bonelike® was established (67±10 %), with no fibrous interface. Therefore, Bonelike® is a single-handedly viable osteoconductive synthetic grafting material as it has been demonstrated from the profiles of radiological, histological and scanning electron microscopy analyses for the six months implantation period.

In Vitro Mineralisation of Human Bone Marrow Cells Cultured on Bonelike

Bonelike is a CaO-P2O5 based glass-reinforced hydroxyapatite (HA) designed to mimic the inorganic composition of the bone tissue. This work evaluates the response of human bone marrow cells to Bonelike  concerning cell proliferation and osteoblast differentiation. HA was used as control material. Results showed that Bonelike  allowed the proliferation of bone marrow cells and their complete differentiation, as evidenced by t he formation of cell-mediated mineralisation. In comparison with HA, Bonelike  had a positive effect on the expression of alkaline phosphatase and also on the formation of a mineralised matrix, two osteobla st markers. Introduction Bonelike is a synthetic hydroxyapatite (HA) that is sintered in the pr esence of CaO-P 2O5-based glasses using a patented process [1]. This synthetic bone graft w as designed to improve the mechanical properties of calcium phosphate ceramics and mimic the inorganic composition of bone tissue. The physicochemical and mechanical behaviour of Bonelike  hav been extensively reported in literature [1-3]. Previous in vitro biological studies showed that glass-reinforced HA composites al low the proliferation of MG63 osteoblast-like cells and human bone marrow ce lls and the expression of osteoblast markers [4-6]. Also, in vivo studies performed in a rabbit model demonstrated that Bonelike composites induced earlier new bone formation around implants than HA [7]. Recently, a composite prepared by the addition (4 wt %) of a glass with the composition of 65P2O5-15CaO-10CaF 2-10Na2O (in % mol) to HA was subject of clinical trials in implantol ogy and maxillofacial surgery [8]. This study demonstrated extensive new bone formation around implanted granules and continuous replacement by new bone. Osteoblasts a re the cells responsible for the formation of the bone tissue at the bone/material interface and the present work evaluates the response of human bone marrow cells to Bonelike  composite, with the same chemical composition, concerning cell proliferation and osteoblast differentiation. HA was used as control material. Key Engineering Materials Online: 2003-12-15 ISSN: 1662-9795, Vols. 254-256, pp 821-824 doi:10.4028/www.scientific.net/KEM.254-256.821

Bone Marrow Stem Cells Added to a Hydroxyapatite Scaffold Result in Better Outcomes after Surgical Treatment of Intertrochanteric Hip Fractures

Introduction. Intertrochanteric hip fractures occur in the proximal femur. They are very common in the elderly and are responsible for high rates of morbidity and mortality. The authors hypothesized that adding an autologous bone marrow stem cells concentrate (ABMC) to a hydroxyapatite scaffold and placing it in the fracture site would improve the outcome after surgical fixation of intertrochanteric hip fractures. Material and Methods. 30 patients were randomly selected and divided into 2 groups of 15 patients, to receive either the scaffold enriched with the ABMC (Group A) during the surgical procedure, or fracture fixation alone (Group B). Results. There was a statistically significant difference in favor of group A at days 30, 60, and 90 for Harris Hip Scores (HHS), at days 30 and 60 for VAS pain scales, for bedridden period and time taken to start partial and total weight bearing (P < 0.05). Discussion. These results show a significant benefit of adding a bone marrow enriched scaffold to surgical fixation in intertrochanteric hip fractures, which can significantly reduce the associated morbidity and mortality rates. Conclusion. Bone marrow stem cells added to a hydroxyapatite scaffold result in better outcomes after surgical treatment of intertrochanteric hip fractures.

Patient-specific instrumentation in total knee arthroplasty. Should we adopt it? ☆

Total knee arthroplasty (TKA) is a surgical procedure of paramount relevance that restores a substantial degree of function in arthritic knees. Increased consideration has been given to the influence of limb alignment on longevity after TKA, as errors in component placement can be associated with inferior function and compromised long-term performance. Consequently, numerous studies comparing patient-specific instrumentation (PSI) to standard instruments (SI) have been published. Patient-specific approaches use preoperative imaging to create specific materials for each patients anatomy and were designed to achieve a higher rate of success in TKA, causing the entire procedure to be more efficient and cost-effective. However, it is not clear to what degree these studies support the potential advantages of PSI. Thus, the present study aimed to review the current evidence comparing PSI to SI, concerning alignment, cost-effectiveness, and postoperative functional evaluation.

Complications of coracoid transfer procedures for the treatment of recurrent shoulder dislocation

HighlightsCoracoid transfer procedures are known to be successful when it comes to prevention of recurrence. However, all of them are invariably associated with high complication rates, especially limited range of motion.Arthroscopic technique was found to have an overall lower rate of complications when compared to the open procedures.Despite being scarce, the CHSJ data roughly overlap the literature. Background Different surgical procedures have been described for the treatment of the recurrent anterior dislocation of the shoulder. Despite the documented success of the open procedures, some studies suggest that the arthroscopic technique leads to more favorable results. However, there still seems to be some disagreement concerning the incidence of complications, when comparing open and arthroscopic techniques. Objective and methods As an attempt to clarify these doubts about the incidence of complications associated with the different techniques, this study contains a free literature review along with a retrospective case series of the patients who underwent these procedures in an University hospital in the past 10 years. Discussion and conclusion There are various techniques for the treatment of the recurrent dislocation of the shoulder, all of them with known success when it comes to prevention of recurrence. However, all of them are invariably associated with high complication rates. Despite being associated with a slightly higher re‐operation rate, in the literature, the arthroscopic technique was found to have an overall lower rate of complications when compared to the open procedures. Centro Hospitalar São João (CHSJ) presented a higher rate of screw related complications and revision surgery than the literature. However, concerning other complications and when assessing the procedures individually, no tendency was verified. One can therefore conclude that, despite being scarce, the Centro Hospitalar São João CHSJ data roughly overlap the literature.

The Benefit Of Bone Marrow Concentrate In Addition To A Glass‐Reinforced Hydroxyapatite For Bone Regeneration: An In Vivo Ovine Study

This study evaluates the ability of a Glass Reinforced Hydroxyapatite Composite (GRHC), in a new microporous pellet formulation with autologous bone marrow concentrate (BMC), to enhance bone regeneration and new bone formation. Ninety non‐critical sized bone defects were created in the femurs of nine Merino breed sheep and randomly left unfilled (group A), filled with GRHC pellets alone (group B) or filled with GRHC pellets combined with BMC (group C). The sheep were sacrificed at 3 weeks (three sheep), 6 weeks (three sheep) and 12 weeks (three sheep) and histological analysis (Light Microscopy‐LM), scanning electron microscopy (SEM) and histomorphometric analysis (HM) were performed. At 3, 6, and 12 weeks, HM revealed an average percentage of new bone of 48, 72, 83%; 25, 73, 80%, and 16, 38, 78% for Groups C, B and A respectively (significantly different only at 3 weeks p < 0.05). LM and SEM evaluation revealed earlier formation of well‐organized mature lamellar bone in Group C. This study demonstrates that the addition of a bone marrow concentrate to a glass reinforced hydroxyapatite composite in a pellet formulation promotes early bone healing.

The Benefit of a Human Bone Marrow Stem Cells Concentrate in addition to an Inorganic Scaffold for Bone Regeneration: An In Vitro Study

Background. This work compares the osteoblastic behaviour of a bone marrow (BM) aspirate and a prepared BM concentrate of nucleated cells associated with a glass reinforced hydroxyapatite composite (GRHC) in a microporous pellet formulation. Methods. BM aspirate (30 mL) was collected during 3 orthopedic surgical procedures, and a concentration system was used to achieve 3 rapid preparations of a concentrate of nucleated cells (3 mL) from the BM aspirates. The BM aspirates (53% cell viability; 2.7 × 106 nucleated cell/mL) and the BM concentrates (76% cell viability; 2 × 107 nucleated cell/mL) were cultured over glass reinforced hydroxyapatite pellets, at the same volume/mass ratio, for 30 days. Cultures performed in standard tissue culture plates were used as control. Results. The colonized BM concentrate/material constructs exhibited a representative osteoblastic proliferation/differentiation pathway, evidenced by a high alkaline phosphatase (ALP) activity, expression of collagen type 1, ALP, BMP-2, M-CSF, RANKL, and OPG, and formation of a calcium phosphate mineralized matrix. A clear improved behaviour was noticed compared to the BM aspirate/material constructs. Conclusions. The results suggest the benefit of using an autologous BM concentrate/material construct in the clinical setting, in bone regeneration applications.