torsion parameters
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INTRODUCTION: Deep brain stimulation (DBS) of the internal globus pallidus (GPi) is a well-established, effective treatment for dystonia. Substantial variability of therapeutic success has been the one of the drivers of an ongoing debate about proper stimulation site and settings, with several indications of the notional sweet spot pointing to the lower GPi or even subpallidal area. METHODS: The presented patient-blinded, random-order study with cross-sectional verification against healthy controls enrolled 17 GPi DBS idiopathic, cervical or generalised dystonia patients to compare the effect of the stimulation in the upper and lower GPi area, with the focus on sensorimotor network connectivity and local activity measured using functional magnetic resonance. RESULTS: Stimulation brought both these parameters to levels closer to the state detected in healthy controls. This effect was much more pronounced during the stimulation in the lower GPi area or beneath it than in slightly higher positions, with stimulation-related changes detected by both metrics of interest in the sensorimotor cortex, striatum, thalamus and cerebellum. CONCLUSIONS: All in all, this study not only replicated the results of previous studies on GPi DBS as a modality restoring sensorimotor network connectivity and local activity in dystonia towards the levels in healthy population, but also showed that lower GPi area or even subpallidal structures, be it white matter or even small, but essential nodes in the zona incerta as nucleus basalis of Meynert, are important regions to consider when programming DBS in dystonia patients.
- MeSH
- dospělí MeSH
- dystonické poruchy terapie patofyziologie diagnostické zobrazování MeSH
- dystonie terapie patofyziologie diagnostické zobrazování MeSH
- globus pallidus * diagnostické zobrazování patofyziologie MeSH
- hluboká mozková stimulace * metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * metody MeSH
- průřezové studie MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
PURPOSE OF THE STUDY: To investigate the effects of anatomical variations on the mechanism of scaphoid fracture by comparing the radiologic parameters of the wrist of patients with and without scaphoid fracture after a fall on an outstretched hand. MATERIAL AND METHODS: Cross-sectional comparative retrospective analysis of radiographs of patients with (Group 1, n=169) and without scaphoid fracture (Group 2, n=188). Morphometric data were measured including radial inclination (RI), radial height (RH), ulnar variance (UV), carpal height (CH) ratio, revised carpal height (RCH) ratio and palmar tilt of the distal radius (PT). Receiver operating characteristics (ROC) curve analysis was used to assess the diagnostic performance for each variable with statistically significant difference. RESULTS: The mean RI and PT degrees and RH length were statistically significantly higher, and the mean UV was lower in Group 1 compared to Group 2. No difference was determined between the groups with respect to the CH ratio and RCH ratio. With ROC curve analysis, the cut-off value with the highest odds ratio was determined as RH (Cut-off value=10.77 mm, OR=21.886). CONCLUSIONS: Although higher RI, RH, PT values and more negative ulnar variance were observed in the scaphoid fracture group compared to the non-fracture group, ROC curve analysis showed that only increased RH can be considered as a possible risk factor for scaphoid fractures after fall on an outstretched hand. KEY WORDS: radiographs, risk factor, scaphoid fracture, wrist morphology.
- MeSH
- člunkovitá kost * zranění diagnostické zobrazování MeSH
- dospělí MeSH
- fraktury kostí * diagnostické zobrazování etiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- poranění zápěstí diagnostické zobrazování etiologie MeSH
- průřezové studie MeSH
- radiografie * metody MeSH
- retrospektivní studie MeSH
- úrazy pádem * MeSH
- zápěstní kloub diagnostické zobrazování MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Background: Degenerative cervical spinal cord compression is becoming increasingly prevalent, yet the MRI criteria that define compression are vague, and vary between studies. This contribution addresses the detection of compression by means of the Spinal Cord Toolbox (SCT) and assesses the variability of the morphometric parameters extracted with it. Methods: Prospective cross-sectional study. Two types of MRI examination, 3 and 1.5 T, were performed on 66 healthy controls and 118 participants with cervical spinal cord compression. Morphometric parameters from 3T MRI obtained by Spinal Cord Toolbox (cross-sectional area, solidity, compressive ratio, torsion) were combined in multivariate logistic regression models with the outcome (binary dependent variable) being the presence of compression determined by two radiologists. Inter-trial (between 3 and 1.5 T) and inter-rater (three expert raters and SCT) variability of morphometric parameters were assessed in a subset of 35 controls and 30 participants with compression. Results: The logistic model combining compressive ratio, cross-sectional area, solidity, torsion and one binary indicator, whether or not the compression was set at level C6/7, demonstrated outstanding compression detection (area under curve =0.947). The single best cut-off for predicted probability calculated using a multiple regression equation was 0.451, with a sensitivity of 87.3% and a specificity of 90.2%. The inter-trial variability was better in Spinal Cord Toolbox (intraclass correlation coefficient was 0.858 for compressive ratio and 0.735 for cross-sectional area) compared to expert raters (mean coefficient for three expert raters was 0.722 for compressive ratio and 0.486 for cross-sectional area). The analysis of inter-rater variability demonstrated general agreement between SCT and three expert raters, as the correlations between SCT and raters were generally similar to those of the raters between one another. Conclusions: This study demonstrates successful semi-automated compression detection based on four parameters. The inter-trial variability of parameters established through two MRI examinations was conclusively better for Spinal Cord Toolbox compared with that of three experts' manual ratings.
- Publikační typ
- časopisecké články MeSH
Úvod a cíl: Fraktura nikl-titanových nástrojů v endodoncii je komplikace, se kterou se dříve nebo později v ordinaci setká většina stomatologů. Stojí za ní zejména dva základní mechanismy a těmi jsou překročení limitu cyklické únavy, překročení limitu torzní únavy a jejich vzájemná kombinace. Účelem tohoto článku je osvětlit mechanismus fraktury nikl-titanového endodontického nástroje na podkladě cyklické únavy, faktory ji ovlivňující a s tím spojenou problematiku laboratorního testování. Metodika: Vyhledávání literatury bylo provedeno pomocí PubMed (MEDLINE), ScienceDirect a databáze Wiley Online Library. K vyhledání literatury byla použita klíčová slova týkající se dané tematiky. Poté byla provedena selekce vhodných zdrojů. Mechanismus fraktury nástroje: Fraktura na podkladě cyklické únavy má tři základní fáze. Iniciace, což je časový úsek, kdy dochází k morfologickým změnám zejména na povrchu a těsně pod povrchem nástroje do vzniku primární praskliny. Poté dochází k jejímu postupnému růstu za vzniku charakteristických pruhů. Jakmile dojde k překročení limitu lomové houževnatosti, přichází na řadu definitivní selhání a separace části nástroje. Faktory ovlivňující frakturu: Jeden z nejpodstatnějších vlivů na vznik fraktury má kvalita slitiny. Rotační endodontické nástroje v dnešní době můžeme rozdělit podle struktury na nástroje s převahou martenzitu nebo austenitu. Z pohledu cyklické únavy jsou martenzitické nástroje výrazně odolnější než nástroje austenitické. Drsnost povrchu má z fyzikálního hlediska přímý vliv na vznik fraktury, jelikož nerovnosti slouží jako predispoziční místa pro koncentraci napětí. Důležitý vliv má i tvar nástroje, který pozitivně ovlivňuje rezistenci vůči cyklické únavě, pokud má nástroj menší průměr. S rostoucím obsahem průřezu nástroje se zvyšuje tahové napětí na jeho povrchu, a proto dochází k rychlejšímu selhání. Okolní teplota signifikantně ovlivňuje vlastnosti nástrojů. Vyšší teplota snižuje odolnost vůči cyklické únavě. Je třeba brát v úvahu, že se nástroj může v teplotě místnosti chovat diametrálně odlišně v porovnání s teplotou v kořenovém kanálku. Nesmíme zapomínat ani na parametry kořenového kanálku, které zásadním způsobem ovlivňují selhání nástroje. Velmi důležitý je také typ rotace nástroje v kořenovém kanálku. Z tohoto pohledu jednoznačně můžeme říct, že rotační mód zkracuje dobu rezistence nástroje v porovnání s těmi recipročními. Pro testování cyklické únavy dosud nebyl určen vhodný výplachový roztok. Závěr: Tematika selhání endodontických nástrojů na bázi cyklické únavy je velmi obsáhlá. Její vývoj a pochopení může pomoci výrobě odolnějších nástrojů, a tím minimalizovat přítomnost této komplikace v ordinaci praktického zubního lékaře.
Introduction and aim: The fracture of Ni-Ti instruments is a complication that most dentists will sooner or later encounter in the dental office. There are mainly two basic mechanisms behind it and these are exceeding the cyclic fatigue limit, exceeding the torsional fatigue limit and their mutual combination. The purpose of this article is to describe the fracture mechanism of a nickel-titanium endodontic instrument based on cyclic fatigue, the influencing factors and related issues of laboratory testing. Methods: Literature searches were performed using PubMed (MEDLINE), ScienceDirect and the Wiley Online Library database. Keywords related to the topic were used to search the literature. Then suitable sources were selected. Instrument fracture mechanism: A cyclic fatigue fracture consists of three basic phases. Initiation, which is the period of time when morphological changes occur, especially on the surface and subsurface of the instrument, until the formation of the primary crack. After that the crack gradually grows with the formation of characteristic striations. As soon as the fracture toughness limit is exceeded, it is time for final failure and separation of part of the instrument. Factors affecting fracture: One of the most significant effects on fracture formation has the quality of the alloy. Today, rotary endodontic instruments can be divided according to their structure into the instruments with a predominance of martensite or austenite. From the point of view of cyclic fatigue, martensitic instruments are significantly more durable than austenitic. From a physical point of view, surface roughness has a direct effect on fracture formation as surface irregularities serve as predisposing points for stress concentration. The shape of the instrument also has an important effect, as the smaller diameter of the instrument and its core has a positive effect on the resistance to cyclic fatigue. As the cross-section area of the instrument increases, the tensile strain on its surface increases, thus, a faster failure occurs. The ambient temperature significantly affects the properties of the instruments. Higher temperature reduces resistance to cyclic fatigue. It should be kept in mind that the instrument may behave diametrically differently at room temperature compared to the root canal temperature. We must also not forget the parameters of the root canal, which fundamentally affect the failure of the instrument. The type of instrument movement kinematics in the root canal is also very important. From this point of view, we can clearly say that the rotational mode reduces the instruments's resistence to cyclic fatigue compared to reciprocal ones. An ideal irrigant has not yet been identified for cyclic fatigue testing. Conclusion: The topic of failure of endodontic instruments based on cyclic fatigue is very extensive. Its development and understanding can help the production of more durable instruments and thus minimize the presence of this complication in a general dental office.
- Klíčová slova
- únava materiálu, fraktura NiTi nástroje v endodoncii,
- MeSH
- lidé MeSH
- nikl MeSH
- selhání zařízení * MeSH
- titan MeSH
- zubní nástroje * škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
PURPOSE OF THE STUDY The aim of this retrospective study was to assess the subjective evaluation of treatment by patients with respect to their return to work and recreational sport following the fracture of clavicle diaphysis with posttraumatic shortening of 1.5 cm, or more, treated non-operatively and surgically. MATERIAL AND METHODS Our group of patients consisted of 51 patients (14 females, 37 males) aged between 18 and 89 years (average age 46 years). We concentrated on the parameters of sex, age, side of injury, extent of posttraumatic shortening, method of treatment, return to work or recreational sport, DASH score at one year post non-operative or surgical treatment. Patients who sustained a pathological fracture, fractures of the clavicle combined with an injury of the acromioclavicular joint or simultaneous fracture of the humerus or the ribs were excluded from the study. Patients with open fractures or re-fractures were excluded as well. The indication for treatment selection was based on pre-operative discussion of the doctor with the patient and the Informed Consent was signed. The patient was informed about different treatment options. A shorter period of fixation of the arm and post-operative physiotherapy was mentioned in connection with surgical treatment as well as potential surgical complications. A statistical analysis comparing the data in both groups was conducted using the Fisher exact test. The p-value of 0.05 or less was considered as statistically significant. RESULTS The right side was affected 26 times, the left side 25 times. The shortening ranged from 1.5 to 3.7 cm. 24 patients (8 females, 16 males) aged 21 to 89 years (average 54 years) were treated non-operatively. 27 patients (6 females, 21 males) aged 18 to 74 years (average 38 years) underwent surgery. The difference in sex distribution in both groups was not statistically significant (p = 0.5311). According to the Robinson classification, there were 17 patients with type 2A2 fractures, of whom 8 underwent surgery and 9 were treated non-operatively, 19 patients with type 2B1 fractures, of whom 9 underwent surgery and 10 were treated non-operatively, and 15 patients with type 2B2, of whom 10 underwent surgery and 5 were treated non-operatively. The surgically treated patients prevailed in type 2B2 only, but this difference was not statistically significant (p = 0.2350). In the non-operatively treated group, 23 out of 24 patients returned to pre-injury activities in 3 months on average. Ten patients (48%) reported reaching the same function as on the other side. In the DASH score evaluation, 11 patients reached the value of 0-3.3, five patients 3.4-10, six patients 10.1-30.0 and two reached the score of more than 30. In the evaluation of capacity to work, 15 out of 24 patients were able to work, 11 of them without any restrictions or difficulties. In the evaluation of the sport and playing musical instrument module, 9 out of 24 patients did not engage in sports activities or do not play any musical instruments. In the surgically treated group, 26 out of 27 patients returned to pre-injury activities within 6 weeks. 19 (70%) patients reported reaching the same function as on the other side. In the DASH score evaluation, 19 patients reached the value of 0-3.3, two patients 3.4-10, 5 patients 10.1-30.0 and one patient with nonunion 72.5. Comparison of the average values of the DASH score demonstrated slightly better results achieved by surgical treatment (9.03 vs 6.77). When assessing the work module, 24 out of 27 patients returned to work, 20 of them without any restrictions or difficulties. Out of 27 patients, 4 patients were no longer able to engage in sports activities or to play a musical instrument. Of the 23 remaining patients, 18 did not have any problems, 5 suffered from minimal problems. The group of patients treated non-operatively included one case of non-union and the same applies to the surgically treated group. In 3 patients the removal of hardware was performed, 3 patients underwent revision of the surgical wound because of infection. DISCUSSION The recommendation of the weight-bearing of the upper extremity was similar in both groups, 12 weeks post injury/surgery on average. It is clear that sooner return to work or sports activities in the surgically treated group was preferred by younger patients who expected quicker recovery. Younger patients were less patient and more eager to return to work and sports, while the older patients, on the other hand, were more cautious about possible complications of surgery. CONCLUSIONS The results of our study did not identify any correlation between the clavicle shortening and the indication for surgical treatment. Surgical treatment was preferred by younger patients, more frequently by males. The rationale was supported by the perspective of sooner return to work and favourite sports activities. Their decision was not affected by the known risks of surgical treatment. Evaluation of the DASH score at one year after injury/surgery showed similar results. A higher incidence of complications in the surgically treated group did not lead to negative evaluation of the selected treatment modality by the highly motivated group of patients either. Key words: fractures of the clavicle diaphysis, non-operative treatment, surgical treatment, return to work, return to sports activities, functional results at 1 year.
- MeSH
- diafýzy MeSH
- dospělí MeSH
- fraktury kostí * komplikace chirurgie MeSH
- klíční kost zranění MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- sporty * MeSH
- vnitřní fixace fraktury metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY Pelvic trauma causes severe threats especially to polytraumatized patients. Not only it is in itself a possible cause for significant bleeding, but it also indicates a high risk for intra-abdominal injuries. The initial treatment of patients with pelvic trauma follows the ATLS principles of priority-oriented treatment. To examine the value of this highly standardized concept and to evaluate the effect of different patient collectives on early outcome parameters, two large collectives from Germany and Qatar were analyzed regarding injury parameters and early outcomes. MATERIAL AND METHODS Patients were recruited in Hamad General Hospital, Doha, Qatar (HGH) and BG Trauma Center Ludwigshafen, Germany (BG). All patients that were treated with a pelvic fracture between 2013 and 2016 were included in this retrospective analysis. Demographic parameters were collected as well as type of injury and the frequency of complication parameters as pneumonia, acute kidney failure, ARDS, sepsis and amount of blood transfusion. 1436 patients with pelvic fracture (645 from BG and 791 from HGH) were recruited. The mean age was 57.4 years in the BG and 33.6 years in the HGH group (p<0.000). The mean ISS was 17.81 in the BG and 15.88 in the HGH group (p=0.009). The mean pelvic AIS was 2.65 in the BG and 2.25 in the HGH group (p<0.000). RESULTS The mean frequency of complications was 9.3% in the BG and 9.9% in the HGH group (p=0.128). The mean frequency of ARDS was significantly higher in the BG group than in the HGH group (5.6% vs. 1.8%, p<0.000). The mean frequency of blood transfusion was significantly lower in the BG group than in the HGH group (28.8% vs. 39.2%, p<0.000). CONCLUSIONS Despite significant differences in the two collectives, this analysis shows comparable results regarding early outcome parameters in patients with pelvic injuries. In total, pelvic injuries are accompanied by a relatively high complication risk and need to be evaluated and treated according to priority-based algorithms. Key words: ATLS®, pelvic injury, complications, polytrauma.
- MeSH
- fraktury kostí * epidemiologie terapie MeSH
- jednotky intenzivní péče MeSH
- lidé středního věku MeSH
- lidé MeSH
- pánevní kosti * zranění MeSH
- polytrauma * terapie MeSH
- retrospektivní studie MeSH
- skóre závažnosti úrazu MeSH
- traumatologická centra MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Katar MeSH
- Německo MeSH
Although current AMBER force fields are relatively accurate for canonical B-DNA, many noncanonical structures are still described incorrectly. As noncanonical motifs are attracting increasing attention due to the role they play in living organisms, further improvement is desirable. Here, we have chosen the Z-DNA molecule, which can be considered a touchstone of the universality of empirical force fields, since the noncanonical α and γ backbone conformations native to Z-DNA are also found in protein-DNA complexes, i-motif DNA, and other noncanonical DNAs. We show that spurious α/γ conformations occurring in simulations with current AMBER force fields, OL15 and bsc1, are largely due to inaccurate α/γ parametrization. Moreover, stabilization of native Z-DNA substates involving γ = trans conformations appears to be in conflict with the correct description of the canonical B-DNA structure. Because the balance of the native and spurious conformations is influenced by nonadditive effects, this is a difficult case for an additive dihedral energy scheme such as AMBER. We propose new α/γ parameters, denoted OL21, and show that they improve the stability of native α/γ Z-DNA substates while keeping the canonical DNA description virtually unchanged, thus representing a reasonable compromise within the additive force field framework. Although further extensive testing is needed, the new modification appears to be a promising step toward a more reliable description of noncanonical DNA motifs and provides the best performance for Z-DNA molecules among current AMBER force fields.
- MeSH
- B-DNA chemie MeSH
- konformace nukleové kyseliny MeSH
- simulace molekulární dynamiky MeSH
- Z-DNA * MeSH
- Publikační typ
- časopisecké články MeSH
Úvod: Osteoporóza je čoraz rozšírenejším ochorením, rovnako ako diabetes mellitus (DM). V súčasnosti je už akceptovaný fakt, že osteoporotické zlomeniny sú závažnou komorbiditou a komplikáciou DM. Riziko fraktúr je zvýšené jednak u pacientov s DM 1. typu (DM1T), u ktorých je znížená kostná denzita, avšak aj u pacientov s DM 2. typu (DM2T), a to napriek normálnym hodnotám kostnej denzity. Cieľ: Zistiť zmeny kostnej denzity u pacientok s DM1T a DM2T a porovnať s kontrolnou skupinou bez poruchy metabolizmu sacharidov. Súbor a metodika: Analyzovali sme kohortu postmenopauzálnych žien s DM a matchovanou kontrolnou skupinou. Súbor tvorilo 145 žien, pričom 76 malo DM (25 malo DM1T, 51 malo DM2T) a 69 žien bolo bez poruchy metabolizmu glukózy. U všetkých pacientok bola vyšetrená centrálna kostná denzita (v oblasti chrbtice a bedra) metodikou DXA, boli vyšetrené parametre glykemickej kompenzácie, boli zmerané antropometrické parametre. Následne sme výsledky štatisticky spracovali. Výsledky: Hodnota kostnej denzity bola u DM1T signifikantne (p = 0,01) nižšia oproti kontrolnej skupine v oblasti chrbtice (0,71 ± 0,13 g/cm2 vs 0,98 ± 0,13 g/cm2) aj v oblasti bedra (0,61 ± 0,10 g/cm2 vs 0,81 ± 0,13 g/cm2). Pacientky s DM2T mali vyššiu hodnotu BMD oproti pacientkam s DM1T (LS 0,91 ± 0,16 g/cm2 vs 0,71 ± 0,13 g/cm2; bedro: 0,79 ± 0,17 g/cm2 vs 0,61 ± 0,13 g/cm2). Rozdiel v BMD pacientok s DM2T oproti kontrolnej skupine bol nesignifikantný. Pacientky s DM1T mali oproti pacientkam s DM2T vyšší výskyt osteoporózy (35 % vs 11 %). U diabetičiek s DM2T až 76 % tvorili práve pacientky s osteopéniou. V kontrolnej skupine až 65 % pacientok nemalo ani osteoporózu a ani osteopéniu, 32 % pacientok malo osteopéniu a 3 % osteoporózu. Záver: Postmenopauzálne ženy s DM1T majú výrazne zníženú kostnú denzitu oproti kontrolnej skupine. Pacientky s DM2T majú vyššie hodnoty BMD než u DM1T porovnateľné s nediabetickou populáciou.Tento fakt sťažuje identifikáciu rizikových skupín diabetikov s DM2T. Preto sa v klinickej praxi diskutujú ďalšie modality na zlepšenie hodnotenia rizika osteoporózy u DM2T, jedným z nich je kombinácia denzitometrie a stanovenia trabekulárneho kostného skóre (TBS).
Introduction: Osteoporosis is an increasingly widespread disease, as well as diabetes mellitus. It is now accepted that osteoporotic fractures are a serious co-morbidity and complication of diabetes. The risk of fracture is elevated in patients with Type 1 Diabetes (T1DM), in which bone mineral density is reduced, but also in Type 2 Diabetes (T2DM) patients, in which is the change of bone quality. Objective: To determine changes in bone mineral density (BMD) in patients with T1DM and T2DM, and to compare these changes with the control group without diabetes. Patients and methods: We analyzed a cohort of postmenopausal women with diabetes and a matched control group. The cohort consisted of 145 women, 76 of whom had diabetes mellitus (25 with T1DM, 51 with T2DM), and 69 were without glucose metabolism. For all patients, central bone density (spinal and lumbar spine) was tested by DXA methodology, glycemic control parameters were assessed, and anthropometric parameters were measured. Bone quality was analyzed using TBS software. We then processed the results statistically. Results: In T1DM was the BMD significantly (p = 0.01) lower than in control group (LS: 0.71 ± 0.13 g/cm2 vs. 0.98 ± 0.13 g/cm2; hip: 0.61 ± 0.10 g/cm2 vs. 0.81 ± 0.13 g/cm2). Patients with T2DM had a higher BMD than patients with T1DM (LS: 0.91 ± 0.16 g/cm2 vs. 0.71 ± 0.13 g/cm2; hip: 0.79 ± 0.17 g/cm2 vs. 0.61 ± 0.13 g/cm2). There was no difference between BMD in T2DM versus the control group. Patients with T1DM had a higher incidence of osteoporosis (35 % versus 11 %) compared to patients with T2DM. In diabetes with T2DM up to 76 % had osteopenia. Conclusion: We confirmed that postmenopausal women with T1DM have significantly reduced bone mineral density compared to the control group. Patients with T2DM have higher BMD than T1DM, results of BMD are comparable to non-diabetic population. This fact makes it difficult to identify risk groups (for osteoporotic fractures) in T2DM. Therefore, other modalities, to improve the risk assessment of osteoporosis in T2DM, are discussed. One of them is the combination of densitometry and trabecular bone score.
PURPOSE OF THE STUDY To improve the important torsional, bending and compressive stability in femoral neck fixation, locking plates have been the latest contribution. However, increased strength by restricted fracture motion may come at expense of an altered load distribution and failure patterns. Within locking plate technology, the important intermediate fracture compression may principally be achieved by multiple sliding screws passing through a sideplate fixed to the femur or connected to an interlocking plate not fixed to the femur laterally, sliding "en bloc" with the plate. While biomechanical studies may deliver the short-time patient safety requirements in implant development, no adequate failure evaluation has been performed with interlocking devices ex vivo in this setting. In the present biomechanical study, we analysed if a novel femoral neck interlocking plate with pins could improve fixation performance by changing the parameters involved in the failure mechanism in terms of fixation strength, fracture motion, load distribution and failure pattern. MATERIAL AND METHODS Sixteen pairs of human femurs with stable subcapital osteotomies were fixated by 2 pins or 3 pins interlocked in a plate using a paired design. Femurs were loaded non-destructively to 10° torsion around the neck axis, 200 N anteroposterior bending and 500 N vertical compression in 7° adduction with 1 Hz in 20 000 cycles, and were subsequently subjected to destructive compression to evaluate failure patterns. Bending stiffness, compressive stiffness and displacement from compressive testing reflected fracture motion. Torque and compression to failure replicated known failure mechanisms and defined strength. To evaluate load distribution, associations between biomechanical parameters and measured local bone mineral measurements by quantitative CT were analysed. RESULTS Interlocked pins increased mean strength 73% in torsion and 39% in compression (p = 0.038). Strength was related to all 4 regional mineral masses from the femoral head to subtrochanterically with interlocking (r = 0.64-0.83, p = 0.034), while only to mineral masses in the femoral head in compression and to the head, neck and trochanterically in torsion with individual pins (r = 0.67-0.78, p = 0.024). No difference was detected in fracture motion or failure pattern. DISCUSSION Within the last decade, angular stable implants have expanded our therapeutic arsenal of femoral neck fractures. Increased stability at the expense of altered devastating failure patterns was not retrieved in our study. The broadened understanding of the effect of interlocking pins by an isolated plate as in the current study involved the feature to gain fixation strength. By permitting fracture compression, and through a significant change of correlations between mechanical parameters and local bone mineral factors, a lateral redistribution of load with interlocked pins from the fragile bone medially to the more solid lateral bone was demonstrated. Regarding the long-term patient safety of interlocked pins and healing complications of non-union and segmental collapse of the femoral head, a definite conclusion may be premature. However, the improved biomechanics of an interlocking plate must be considered a favourable development of the pin concept. CONCLUSIONS Interlocked pins may improve fixation performance by a better load distribution, not by restricting fracture motion with corresponding altered failure patterns. This is encouraging and a challenge to complete further studies of the interlocking plate technology in the struggle to find the optimal treatment of the femoral neck fracture. Key words: femoral neck fracture, biomechanics, cadaver bone, bone mineral, internal fixation, locking plate, interlocked pins.
- MeSH
- biomechanika MeSH
- kostní destičky MeSH
- kostní hřeby MeSH
- kostní šrouby * MeSH
- krček femuru * chirurgie MeSH
- lidé MeSH
- mrtvola MeSH
- vnitřní fixace fraktury MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY Comparison of the outcomes of clavicle midshaft fractures using two different surgical techniques, namely intramedullar osteosynthesis using elastic stable intramedullary nailing (ESIN) with medial cap and extramedullar plate osteosynthesis. MATERIAL AND METHODS The prospective randomized trial was conducted at the Department of Trauma Surgery of the Department of Surgery of the University Hospital Hradec Králové in the Czech Republic at the Level I Trauma Center between 2014 and 2018 and compared two types of osteosynthesis of clavicle midshaft fractures. 60 patients were enrolled in the study and were randomly assigned to one of the two groups. In Group 1, the participants were treated by ESIN and in Group 2 by plate osteosynthesis. The operative technique was chosen by the sealed envelope method. According to the randomization list created by a specialised statistical company, every envelope was marked with a unique number and contained the intramedullar "IM", or the extramedullar "EM" sign. RESULTS The observation of statistical parameters by unpaired t test detected significantly different results: a shorter incision using ESIN osteosynthesis (median = 2.9 cm) compared with plate osteosynthesis (median 14 cm, p < 0.001), longer X-ray exposure using ESIN (median = 325 s) compared with plate osteosynthesis (median = 16.5 s, p < 0.001) and radiation dose using ESIN (median = 996 cGy/cm2) compared with plate osteosynthesis (median = 4 cGy/cm2, p < 0.001). The difference in other parameters such as operative time, in-patient length of stay and duration of rehabilitation was not statistically significant. The time to clavicle fracture repair was comparable in both the surgical arms, i.e. approximately 3 months. Also, the duration of incapacity for work was not statistically different. Functional Constant Shoulder Score at a one-year followup is comparable in both the two arms (p = 0.268). The Dunn s method necessitated a longer operative time when treating multifragmental midshaft clavicle fracture by the ESIN compared to simple fractures. No statistically significant difference was detected in the operative time of different procedures and in the number of bone fragments. The functional outcome was excellent in 25 patients (83%) in each method. DISCUSSION Most midshaft clavicle fractures are still treated non-operatively with good outcomes. The indication for surgical treatment is the dislocation of fragments greater than the width of the clavicle bone, the shortening of fragments greater than 2 cm and the angulation of more than 30°. Patient after operative treatment profits from bone healing by absolute or relative stability. In recent years, new intramedullar techniques other than open plate reduction and fixation have emerged. For example, elastic stable intramedullary titan nailing. Both the methods are full-fledged without functional differences in longterm follow-up. CONCLUSIONS We consider the intramedullar osteosynthesis to be the most appropriate surgical approach for simple midshaft spiral, oblique and transverse clavicle fractures and also wedge oblique fractures. Plate osteosynthesis is useful for all types of fractures. No statistically significant difference in the rate of bone healing was observed after intramedullar or extramedullar ostesynthesis, but multifragmentary fractures healed faster when plate osteosynthesis was used. The determining factor for the received radiation dose is solely the surgical method, not the type of fracture. There is a statistically significant difference in shorter X-ray exposure and lower received radiation dose in plate fixation and reduction. The complication rate is comparable in both the methods. Key words: elastic stable intramedullary nailing, midshaft clavicle fracture, ESIN, TEN, titan elastic nail, clavicle plate osteosynthesis, 3.5 LCP clavicular plate, indication for midshaft fracture treatment.
- MeSH
- fraktury kostí chirurgie MeSH
- hojení fraktur MeSH
- klíční kost zranění chirurgie MeSH
- kostní destičky MeSH
- kostní hřeby MeSH
- lidé MeSH
- prospektivní studie MeSH
- vnitřní fixace fraktury přístrojové vybavení metody MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
- srovnávací studie MeSH