scholarly journals Is the magnesium screw as stable as the titanium screw in the fixation of first metatarsal distal chevron osteotomy? A comparative biomechanical study on sawbones models

2021 ◽  
Vol 29 (3) ◽  
pp. 230949902110564
Author(s):  
Adem Sahin ◽  
Deniz Gulabi ◽  
Halil Buyukdogan ◽  
Anil Agar ◽  
Bulent Kilic ◽  
...  
Keyword(s):  
Biomechanical Testing ◽  
Biomechanical Study ◽  
Test Machine ◽  
Maximum Displacement ◽  
Titanium Screw ◽  
Chevron Osteotomy ◽  
Titanium Screws ◽  
Significant Difference ◽  
Group 2 ◽  
Student’S T

Background: Distal chevron osteotomy (DCO) is commonly performed in hallux valgus surgery. The fixation of the osteotomy is provided by various implants. The usage of biodegradable implants such as magnesium is gradually increasing due to the advantages they provide. In this study, we aimed to compare the fixation of DCO with magnesium or titanium screw biomechanically. Methods: Twenty sawbones were used. The samples were divided into two equal groups, including ten sawbones for fixation with single headless titanium (group-1) or magnesium screw (group-2). DCO and screw fixations were performed on all samples using the same technique. Biomechanical testing was applied to five samples in each group in cantilever and the other five in a physiological configuration using a computer connected to the electromechanical test machine. The obtained data were evaluated using the Shapiro–Wilk test, Student’s t-test and Mann–Whitney U test on the IBM® SPSS (Statistical Package for the Social Sciences) V22.0 software. Significance was accepted at the p < 0.05 level. Results: There was no statistically significant difference between the magnesium screw and the titanium screw in terms of maximum force, maximum displacement and stiffness measurements in cantilever and physiological loadings ( p > 0.05 for all). Conclusion: This study found no significant difference in biomechanical stability between the magnesium and titanium screws in DCO fixation on sawbones. Further studies with real bones are needed.

scholarly journals Comparison of Bioabsorbable Magnesium versus Titanium Screw Fixation for Modified Distal Chevron Osteotomy in Hallux Valgus

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Baver Acar ◽  
Ozkan Kose ◽  
Adil Turan ◽  
Melih Unal ◽  
Yusuf Alper Kati ◽  
...  
Keyword(s):  
Hallux Valgus ◽  
Screw Fixation ◽  
Clinical Results ◽  
Significant Loss ◽  
Compression Screw ◽  
Titanium Screw ◽  
Chevron Osteotomy ◽  
Valgus Angle ◽  
Significant Difference ◽  
Screw Group

Objective. The purpose of this retrospective study was to compare the clinical and radiological results of magnesium versus titanium screw fixation for modified distal chevron osteotomy in hallux valgus (HV). Materials and Methods. A total of 31 patients who underwent modified distal chevron osteotomy for HV deformity between 2014 and 2017 were reviewed retrospectively. Headless magnesium (Mg) compression screw fixation was applied in 16 patients (17 feet) and headless titanium (Ti) compression screw in 15 patients (17 feet). Patients were followed up for at least 12 months with a mean of 19.0 ± 6.8 months in the Mg screw group and 16.2 ± 6.19 in the Ti screw group, respectively (p: 0.234). Clinical results were evaluated using the American Orthopedic Foot and Ankle Society Hallux metatarsophalangeal-interphalangeal (AOFAS-MTP-IP) scale and a visual analogue scale (VAS). The hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured before and after surgery. Time to osteotomy union and any complications were recorded and compared between the groups. Results. An improvement in the AOFAS-MTP-IP scale and VAS points were recorded in both groups with no statistically significant difference between the groups (p: 0.764 and 0.535, resp.). At the final follow-up examination, HVA and IMA were similar (p: 0.226 and 0.712, resp.). There was no significant loss of correction between the early and final radiographs in respect of HVA and IMA in both groups (p: 0.321 and p: 0.067). Full union of the osteotomy was obtained in all patients. Prolonged (1.5 months) swelling and mild hyperemia around the surgical incision were observed in 1 patient in the Mg group but there was a good response to physical and medical therapy, and the complaints were completely resolved. There were no other significant complications in either group. Conclusion. The results of this study showed that bioabsorbable Mg compression screw fixation has similar therapeutic efficacy to Ti screw fixation in respect of functional and radiological outcomes. Bioabsorbable Mg screw is an alternative fixation material that can be safely used for modified distal chevron osteotomy in HV surgery.

scholarly journals How Does the Presence of Diabetes Affect the Course of Acute Coronary Syndrome in Elderly Patients in Actual Clinical Practice?

2019 ◽  
Vol 15 (1) ◽  
pp. 29-35
Author(s):  
M. R. Atabegashvili ◽  
E. V. Konstantinova ◽  
M. D. Muksinova ◽  
A. E. Udovichenko ◽  
A. P. Nesterov ◽  
...  
Keyword(s):  
Acute Coronary Syndrome ◽  
Elderly Patients ◽  
The Elderly ◽  
St Segment Elevation ◽  
Coronary Syndrome ◽  
Vessel Disease ◽  
Previous Stroke ◽  
Significant Difference ◽  
Group 2 ◽  
Student’S T

The number of elderly patients with diabetes mellitus (DM) is constantly growing in general population. Accordantly, we have the growth of such patients in the group of acute coronary syndrome (ACS).Aim.To compare clinical characteristics of the elderly patient (>75 years old) with and without DM.Material and methods. This retrospective study included 1133 ACS patients who were aged ≥75 years and admitted to the City Clinical Hospital №1 from 01.01.2015 to 31.12.2016. Median age was 80 years, 66% were women. We analyzed 4 patient subgroups: Group 1 – 105 patients with ST-segment elevation myocardial infarction (STEMI) and DM, Group 2 – 254 STEMI patients without DM, Group 3 – 222 non-STEMI patients with DM and Group 4 – 552 non-STEMI patients without DM. We used Student’s t-test and c2 tests to find significant difference between pairs of groups.Results. Median age of patients in 4 groups was 80, 81, 81 and 80 years (p>0.05), age variance was 75-100 years. DM was found in 29% of all elderly patients with no difference between STEMI and non-STEMI groups. STEMI and non-STEMI patients with DM were more likely women. NonSTEMI patients with DM more often had hypertension, previous stroke, lower median Hb (121 vs 127 g/l; p<0.001). Angiography data demonstrated more often three-vessel disease (43% vs 29.7%) and less one-vessel disease (15% vs 25.6%; p<0.05) between groups 3 and 4. Glomerular filtration rate (GFR) <60 ml/min/1.73 m2 occurred in 74%, 73%, 77% and 74% in patients of 4 groups (p>0,05), but GFR<45 ml/min/1.73 m2 was more prevalent in patients with DM than without DM: 45%, 39%, 45%, 36% in 4 groups. Finally, mortality rates didn’t demonstrate significant difference between DM and non-DM patients with STEMI (10% vs 13%; p>0.05) and non-STEMI (7% vs 7%) groups.Conclusion. DM is associated with ACS approximately in one third of the elderly patients and is not associated with its type (STEMI or non-STEMI). In STEMI and non-STEMI patients the female sex and GFR level <45 ml/min/1.73 m2 were associated with DM. In non-STEMI group multi-vessel disease and presence of hypertension and previous stroke were associated with DM. We didn’t find any difference between mortality in elderly patients with and without DM. 

Biomechanical properties of expander compared with conventional screws

2002 ◽  
Vol 97 (3) ◽  
pp. 346-349 ◽  
Author(s):  
Aziz Rassi-Neto ◽  
Antonio Shimano
Keyword(s):  
Maximum Load ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Intergroup Difference ◽  
Content Type ◽  
Significant Difference ◽  
Group 2 ◽  
The Comparative Study ◽  
Screw Group ◽  
Fine Print

Object. A pullout strength biomechanical study was performed in 20 fresh swine vertebral bodies in which titanium expander (Group 1) and conventional screws (Group 2) were placed. Methods. The screws were inserted into the anterosuperior portion of the anterior spine, and assessment was performed after application of loads. The expander screw is composed of two parts: 1) a cover with an external portion comprising tight thin threads; and 2) a compact internal screw inserted through the cover that allows expansion. In the comparative study between the screws in Groups 1 and 2 maximum load was assessed, and the intergroup difference was significant (p = 0.00001 [t-test]); regarding load at the elasticity threshold, a significant difference was also observed (p = 0.0063). With regard to rigidity (stiffness), there was a tendency in both groups toward significance (p = 0.069). With regard to absorbed energy in the elastic phase, statistical analysis showed a significant intergroup difference (p = 0.00439). The expander screw showed a greater load-bearing capacity than the conventional screw. Adhesion to bone in relation to the applied load and displacement was greater (significant tendency) in the expander screw group than in the conventional screw group. Conclusions. The expander screws exhibited a greater capacity to absorb energy in the elastic phase. They adhered better to bone, were easy to insert, and, if necessary, were simple to remove.

A biomechanical study of the instrumented and adjacent lumbar levels after In-Space interspinous spacer insertion

2010 ◽  
Vol 12 (5) ◽  
pp. 560-569 ◽  
Author(s):  
Seoung Woo Park ◽  
T. Jesse Lim ◽  
Jon Park
Keyword(s):  
Biomechanical Testing ◽  
Axial Rotation ◽  
Biomechanical Study ◽  
Lumbosacral Spine ◽  
Experimental Conditions ◽  
Interspinous Spacer ◽  
Spine Model ◽  
Cadaver Specimen ◽  
Significant Change ◽  
Group 2

ObjectInterspinous process implants are becoming more common for the treatment of lumber disc degeneration. The authors undertook this study to evaluate the effect of the In-Space interspinous spacer on the biomechanics of the lumbosacral spine.MethodsSeven L2–S1 cadaver spines were physiologically loaded in extension, flexion, lateral bending, and axial rotation modes. The range of motion (ROM) and intervertebral disc pressure (DP) at the level implanted with an In-Space device and at adjacent levels were measured under 4 experimental conditions. Biomechanical testing was carried out on 7 sequentially prepared specimens in the following states: 1) the intact L2–S1 cadaver spine and 2) the L2–S1 cadaver specimen implanted with an In-Space interspinous spacer at L3–4 (Group 1), 3) after an additional L3–4 discectomy (with the In-Space interspinous spacer still in place) (Group 2), and finally, 4) after removal of the In-Space interspinous spacer, leaving only the discectomized (that is, destabilized) spine model (Group 3).ResultsThe extension ROM at the implanted level after experimental conditions 2 and 3 above was statistically significantly reduced. An increase of ROM at the adjacent levels compensated for the reduction at the implanted level. However, there was no statistically significant change in ROM in any of the other modes of motion at any of the levels studied. Likewise, the DP reduction at L3–4 during extension was statistically significant, but in all other modes of motion, there was no statistically significant change in DP at any measured level. The In-Space interspinous spacer statistically significantly reduced the ROM of the L3–4 motion segment in Groups 1 and 2 (extension: 67%, p = 0.018 and 70%, p = 0.018; flexion: 72%, p = 0.028 and 80%, p = 0.027). After placement of the In-Space interspinous spacer, the DP was decreased at L3–4 in extension for Groups 1 and 2 in the posterior anular region (63%, p = 0.028; 59%, p = 0.043), Group 2 in the center region (73%, p = 0.028), and Groups 1 and 2 in the anterior anular region (57%, p = 0.018; 60%, p = 0.018).ConclusionsThe In-Space interspinous spacer both stabilizes the spine and reduces the intervertebral DP at the instrumented level during extension. The biomechanics for other modes of motion and at the adjacent levels are not affected statistically significantly, however. The device thus performed as intended. It significantly stabilized the motion segments at the instrumented level, but not at the segment adjacent to the instrumented level.

scholarly journals Comparison of Transversal Effects of Different Expansion Protocols: Alt-RAMEC versus RME

2021 ◽  
Vol 7 (2) ◽  
pp. 43-48
Author(s):  
Burak Kale ◽  
Muhammed Hilmi Büyükçavuş
Keyword(s):  
Rapid Maxillary Expansion ◽  
Maxillary Expansion ◽  
Treatment Protocols ◽  
Significant Difference ◽  
Expansion Protocol ◽  
Group 2 ◽  
Width Measurements ◽  
Student’S T ◽  
Digital Caliper ◽  
Student’S T Test

Abstract Objectives The aim of this study is evaluate the transversal effects of the Alt-RAMEC(Alternate Rapid Maxillary Expansion and Constriction) protocol on both craniofacial and dentoalveolar structures and to compare the transversal effects of the RME(Rapid Maxillary Expansion) protocol. Materials and Methods In our archive, selected patients were divided into two groups. Group 1 included 22 patients(12boys,10girls, mean age 11.61±2.11years) who had been treated with 5 weeks of Alt-RAMEC. Group 2 comprised 21 patients(11boys,10girls, mean age 11.66±1.23years) who had been treated with 1 week of RME. Transversal measurements were also performed on the study models pre-(T0) and post-treatment(T1) with digital caliper. Internasal, interzygomatic, interjugular and intergonial width measurements were made on posteroanterior radiographs. The initial measurements and the mean changes within the groups were analysed using a student’s t test. Results According to the results of the study, there was no statistically significant difference between the groups in terms of chronological age, gender distribution and initial values. The expansion protocols showed a statistically significant increase in the widths of intercanine, interpremolar, intermolar and alveolar base widths in the maxilla(p<0.05). No statistically significant changes were observed in both groups(p>0.05) in mandible. The changes in maxillary intercanine, interpremolar widths between the two groups were statistically significant(p<0.05). In the posteroanterior measurements, only statistically significant difference was found between the groups in internasal width(p<0.05). Conclusions Alt-RAMEC and RME protocols are effective treatment protocols for correction of transverse deficiency in growing patients. 5-weeks Alt-RAMEC protocol significantly increased intercanine and interpremolar widths compared to 1-week RME.  Clinical Relevance Since there are no studies in the literature comparing the effects of two different expansion protocols in the transverse direction, this is both the first. Most importantly, clinicians will see which of these two protocols is more singular in the treatment of transversal problems. Keywords: RME, Alt-RAMEC, tranversal measurements

Tendon Transfer Fixation in the Foot and Ankle: A Biomechanical Study Evaluating Two Sizes of Pilot Holes for Bioabsorbable Screws

2003 ◽  
Vol 24 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Keith W. Louden ◽  
Catherine G. Ambrose ◽  
Stacy G. Beaty ◽  
William C. McGarvey ◽  
Thomas O. Clanton
Keyword(s):  
Tendon Transfer ◽  
Biomechanical Testing ◽  
Biomechanical Study ◽  
Hole Size ◽  
Foot And Ankle ◽  
Pilot Hole ◽  
Initial Fixation ◽  
Significant Difference ◽  
Bioabsorbable Screws ◽  
Drill Holes

The purpose of this study was to compare the initial fixation strengths of bioabsorbable screws for tendon transfers in the foot and ankle when the pilot hole size varied. A 7times20 mm screw was used with 5.5 mm and 6.5 mm drill holes, and a 5times20 mm screw was used with 3.9 mm and 4.5 mm drill holes. Biomechanical testing was performed on each tendon transfer in cadaver specimens. A paired t-test showed no significant difference in pullout strength when pilot hole size varied between 79 to 93% of the screw size for the 7 mm screw and 78 to 90% of the screw size for the 5 mm screw. Previous studies have found a critical value of tendon tension equaling 50 N with passive dorsiflexion of the foot. With an average value of approximately 170 N, the 7 mm screw provided three times the requisite strength. The 5 mm screw provided 1.5 times the requisite strength, but the transfer was technically more difficult.

Biomechanical Comparison of 2 Common Techniques of Minimally Invasive Hallux Valgus Correction

2020 ◽  
pp. 107110072095902
Author(s):  
Amiethab Aiyer ◽  
Dustin H. Massel ◽  
Noman Siddiqui ◽  
Jorge I. Acevedo
Keyword(s):  
Minimally Invasive ◽  
Hallux Valgus ◽  
Ultimate Load ◽  
Biomechanical Testing ◽  
Osteotomy Site ◽  
Yield Load ◽  
Chevron Osteotomy ◽  
Significant Difference ◽  
Load To Failure ◽  
Biomechanical Strength

Background: Hallux valgus is one of the most common surgically corrected forefoot deformities. Compared to open procedures, minimally invasive (MIS) treatment of hallux valgus has resulted in decreased operative time, reduced complication rates, and greater patient satisfaction. Historically, distal chevron osteotomies are the standard for moderate hallux valgus correction. To our knowledge, no studies have evaluated biomechanical strength of transverse and chevron distal first metatarsal osteotomy (DMO) constructs. The purpose of this study was to evaluate the biomechanical strength of these techniques. Methods: Eighteen cadaveric specimens (9 matched pairs) were randomized to transverse or chevron DMO. Each technique was performed by a separate fellowship-trained orthopedic foot and ankle surgeon. Radiographic images were analyzed. Biomechanical testing was performed using Instron Mechanical System. Ultimate load to failure, yield load, and stiffness were assessed. A 10-N preload was applied to the sesamoid bones for stability. A coaxial compression rate (10 mm/min) was applied until failure was observed. Mean and standard deviations were compared. All cadaveric specimens were male. Results: There was no significant difference in percent metadiaphyseal shift between osteotomies ( P = .453). The most common mode of failure was fracture at screw insertion site (55.6%), followed by failure at osteotomy site (44.4%). A trend toward increased ultimate load to failure ( P = .480), yield load ( P = .054), and stiffness ( P = .438) among transverse compared to chevron osteotomy was observed, but this difference was not statistically significant. Conclusion: Biomechanical testing demonstrated no significant difference in ultimate load, yield load, and stiffness between MIS transverse and chevron osteotomy constructs; a trend toward increased strength in the transverse osteotomy cohort was observed. Chevron osteotomies may result in early failure by relative ease of cutout through cancellous bone compared to transverse osteotomies in which failure requires cortical cutout. Clinical Relevance: Use of MIS techniques for hallux valgus correction is gaining clinical traction. Although various clinical studies have evaluated outcomes of these MIS techniques, biomechanical studies have been minimal. Specifically, the potential biomechanical benefits of various MIS hallux valgus osteotomy techniques have not been delineated to date. The content of this manuscript is quite timely, given the rise in use of these MIS techniques.

scholarly journals 145 THE ROLE OF CELL APOPTOSIS ON IN VITRO-PRODUCED BEEF CATTLE EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 181 ◽  
Author(s):  
M. Nkadimeng ◽  
E. van Marle-Koster ◽  
T. R. Netshirovha ◽  
T. L. Nedambale ◽  
K. C. Lehloenya
Keyword(s):  
Dna Fragmentation ◽  
Cell Apoptosis ◽  
Assay Method ◽  
Caspase Activity ◽  
Cleavage Rate ◽  
Significant Difference ◽  
Group 2 ◽  
Cellular Stresses ◽  
Student’S T

Successful in vitro development of embryos is dependent upon maintenance of cellular function in the embryonic microenvironment. Exposure of pre-implantation embryos to a variety of cellular stresses can induce apoptosis in all or a fraction of blastomeres. Among the conditions that can induce apoptosis in cattle embryo production in vitro are heat shock, media composition, oxygen levels, and tumour necrosis factor (TNF)-α. The aim of the study was therefore to evaluate the in vitro culture environment of embryos in terms of cell apoptosis through caspase and DNA fragmentation evaluation. A total of 1200 immature oocytes were collected at slaughter from indigenous South African cow ovaries. The cumulus-oocyte complexes were randomly allocated into 2 maturation temperatures, 39°C and 41°C (200/temperature /replicated 6 times), and cultured in M199 + FSH-LH-oestradiol medium under oil at 100% humidity and 5% CO2 for 24 h. Postmaturation, oocytes were subjected to normal subsequent embryo conditions (Rynkowska et al. 2011 Biotechnol. Comput. Biol. Bionanotechnol. 92, 45–53). All matured oocytes were fertilized for 6 h with frozen-thawed Nguni bull semen from 10 bulls replicated 5 times at a concentration of 265 × 106 sperm cells/mL in Bracket and Oliphant medium under oil. The presumptive zygotes from each treatment were cultured into SOF-BSA medium under oil and incubated at 39°C for assessment of cleavage rate post IVF. Produced embryos were divided into 3 groups: 2–4 cell, ≥8 cell embryos, and blastocyst. Two- to four-cell embryos were removed at Day 2, ≥8 cell at Day 5 (mainly 8-cell, morula, and cavitated blastocyst), and expanded blastocyst at Day 7 of embryo culture to determine caspase activity and DNA fragmentation for evidence of apoptosis. Caspase was performed using colourimetric assay on a 96-well microplate reader and monitored at 450 nm reference filter. The DNA fragmentation was examined using the TUNEL assay method and imaging was done using the Alexa Fluor® 488 emission at 519 nm. Data were analysed using SAS 9.2 software (SAS Institute Inc., Cary, NC, USA), and Shapiro-Wilks test was used on the standardized residuals to test for deviations from normality, means of significant effects were compared using Student’s t-l.s.d. at the 95% confidence interval. There was no significant difference on the cleavage rates [39°C (72.0 ± 22.70) and 41°C (67.2 ± 18.9)] and blastocysts [39°C (11.4 ± 2.6) and 41°C (11.2 ± 6.3)] from both maturation temperatures. Caspase activity showed no significant difference on 2–4 cell [39°C (0.015 ± 0.001) and 41°C (0.016 ± 0.002)] and ≥8 cell embryos at both temperatures [39°C (0.022 ± 0.007a) and 41°C (0.032 ± 0.013)]. However, blastocyst differed significantly at both temperatures [39°C (0.037 ± 0.012) and 41°C (0.053 ± 0.005)]. A higher (P < 0.05) DNA fragmentation was observed at 2–4 cell (6.5 ± 2.9), ≥8 cell (13.3 ± 3.1), and blastocyst (48.0 ± 8.2) for embryos produced from 41°C matured oocytes compared to the 39°C maturation group [2–4 cell (2.2 ± 1.2), ≥8 cell (4.5 ± 1.9), and blastocyst (9.7 ± 6.7)]. It is therefore concluded that embryos produced from 41°C matured oocytes can have the same developmental capacity as the 39°C maturation group. Moreover, both temperatures can show signs of apoptosis, however, with more apoptosis evidence in the 41°C than the 39°C maturation group.

scholarly journals NEW GENERATION NAIL VS. PLATE IN THE TREATMENT OF UNSTABLE INTERTROCHANTERIC FEMORAL FRACTURE

2020 ◽  
Vol 28 (6) ◽  
pp. 311-315
Author(s):  
BURAK OZTURAN ◽  
SAMET ERINC ◽  
TAYYAR TAYLAN OZ ◽  
KORHAN OZKAN
Keyword(s):  
Axial Load ◽  
Treated Group ◽  
Fracture Load ◽  
Biomechanical Study ◽  
Level Of Evidence ◽  
Intertrochanteric Femoral Fracture ◽  
Significant Difference ◽  
Group 2 ◽  
Locking Screw ◽  
New Generation

ABSTRACT Objective: To compare antirotator proximal femoral nail (A-PFN) with antirotator dynamic hip screw (A-DHS). Methods: Fourteen proximal femur models with type 31/A2 fracture, according to the AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification, were separated into two groups. Group 1 bones (n = 7) were fixed with A-PFN and Group 2 (n = 7) with A-DHS. A 5 mm/min axial load was applied to femur heads using a testing device. Results: Two of the seven models in the A-PFN group fractured at the proximal, and the other five at distal locking screw level. All models in the A-DHS group fractured at the tightened distal screw region. The median fracture load for the A-PFN group was 132.1 N (97.1-173.69 N range), and for the A-DHS group it was 81.7 N (75.15-89.12 N range). Conclusion: A-PFN-treated unstable intertrochanteric fractured models resisted to higher levels of axial load than the A-DHS-treated group, with statistically significant difference. However, clinical studies are required to support these results. Level of Evidence V, Biomechanical study.

scholarly journals Improved Bone Formation in Osteoporotic Rabbits with the Bone Morphogenetic Protein-2 (rhBMP-2) Coated Titanium Screws Which Were Coated By Using Plasma Polymerization Technique

2014 ◽  
Vol 2 (2) ◽  
pp. 198-208
Author(s):  
Salih Gulsen ◽  
Dilek Cokeliler ◽  
Hilal Goktas ◽  
Aysu Kucukturhan ◽  
Bilgehan Ozcil ◽  
...  
Keyword(s):  
Bone Formation ◽  
Plasma Polymerization ◽  
Bone Morphogenetic Protein 2 ◽  
Titanium Screw ◽  
Morphogenetic Protein ◽  
Titanium Screws ◽  
Group 3 ◽  
Group 2 ◽  
Uncoated Titanium ◽  
Group 1

Delaying of bone fusion in osteoporotic patients underwent spinal stabilization surgery leads to screw loosening, and this causes pseudoarticulation, mobility and fibrosis at vertebral segments. To prevent these complications, the screws coated with recombinant bone morphogenetic protein-2 (rhBMP-2) could be used. To verify this hypothesis, we coated 5 Titanium screws with rhBMP-2 using plasma polymerization method, and also used 10 uncoated screws for making comparison between coated and uncoated screws in different groups. And 15 skeletally mature white New Zealand female rabbits were assigned into three different groups: Group 1(N = 5): No osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 1; group 2 (N = 5): Osteoporosis induction and insertion of uncoated Titanium screw into right sacrum of each rabbit in group 2; group 3 (N = 5) rhBMP-2 coated Titanium screw inserted into right sacrum of each rabbit in group 3. In summary, using of these coated screws provides new bone formation, but causes less fibrosis and less inflammation than uncoated screws at the interface between the coated screw and bone. Then the plasma polymerization technique provides controlled releasing of rhBMP-2 from the screw to the bone tissue in osteoporotic rabbits.

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