1,720,982 research outputs found
Considerations on the animal model and the biomechanical test arrangements for assessing the osseous integration of orthopedic and dental implants
No full textIn implant research, a central objective is to optimize the osseous integration of implants according to their function and scope of application. In the preclinical stage, the animal model is commonly used to study implants for in vivo host tissue response and biomechanical tests are a frequently applied method for characterization of contact phenomena. However, the individual parameters and options for both the animal model and the biomechanical test arrangements vary widely, which can negatively affect the reliability and comparability of the results. In the present method description, we focus on implants for trabecular bone replacement and outline differentiated considerations for optimizing the animal model and the biomechanical test arrangement best suited for the area of application described. In addition, our aim was to present an optimized and strict study protocol for biomechanical push-out tests and step-by-step instructions in order to achieve precise and comparable results.•The rabbit model and the distal femur as an implantation site are ideal for biomechanical assessment of implant osseointegration.•Push-out tests are recommended, in which conformity of the axis is mandatory.•Sequential examination periods are beneficial, e.g. after 4 weeks for osseohealing and after 12 weeks for osseoremodeling.Open-Access-Publikationsfonds 202
Perioperative Injections
No full textAbstract Background The present study used a systematic review to analyse the risk of perioperative injections during arthroscopic reconstruction of the rotator cuff of the shoulder. The questions of interest were whether perioperative local injection increases the infection risk and whether the number of postoperative revisions is increased. Material and Methods A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The keywords used were “shoulder” and “arthroscopy” and “injection” and “risk”. In the course of the study, work that was not also primarily concerned with the reconstruction of the rotator cuff was excluded. English original articles and case series were included that contained at least some arthroscopic reconstructions of the rotator cuff. The risk of bias was determined using the Newcastle-Ottawa Scale. The content of the articles relevant to the research questions was analysed. Results 48 hits were primarily generated. 9 articles corresponded to the inclusion criteria and were analysed. In the 6 studies with details on the injected substances, cortisone was used in 98 – 100% of the cases. The reported infection and revision rates based on insurance data were higher with injection than without. The risk of bias in the studies analysed here was rather low based on the Newcastle-Ottawa Score. The risk of infection after a cortisone injection before, during or after surgery was increased. Injection was associated with infection in up to 8% of cases with injections within two weeks of surgery. The risk of infection was increased by up to 11 times with injections within 4 weeks after the operation. Likewise, the risk of revision surgery after injection was increased, with the time intervals between injection and surgery sometimes differing between studies. Discussion Local infections and to a lesser extent revision surgery are associated with perioperative injections (with cortisone) within 3 months preoperatively and 4 weeks postoperatively. However, there were only database studies of insurance data with several studies from a few centres. Thus, no causal relationships could be proven. Currently, however, the following can be recommended using a cautious approach: The interval between injection with cortisone before surgery should be at least 2 weeks, better 3 months. No cortisone injections should be applied intraoperatively. Postoperatively, cortisone should not be injected for at least 4 weeks. If, in exceptional cases, deviations from these time limits are required, patients should be informed about an increased risk of complications.Zusammenfassung Hintergrund Die vorliegende Arbeit analysierte durch einen systematischen Review das Risiko von perioperativen Injektionen bei arthroskopischer Rekonstruktion der Rotatorenmanschette der Schulter. Von Interesse war die Frage, ob perioperative lokale Injektionen das Infektionsrisiko erhöhen und ob die Anzahl postoperativer Revisionen erhöht ist. Material und Methoden Es wurde eine systematische Durchsicht der Datenbank der U. S. National Library of Medicine/National Institutes of Health (PubMed) und der Cochrane Library unter Anwendung der PRISMA-Checkliste durchgeführt. Als Suchwörter dienten „shoulder“ und „arthroscopy“ und „injection“ und „risk“. Im Verlauf wurden Arbeiten ausgeschlossen, die sich nicht auch primär mit der Rekonstruktion der Rotatorenmanschette beschäftigten. Englischsprachige Originalarbeiten und Fallserien, die mindestens anteilig arthroskopische Rekonstruktionen der Rotatorenmanschette enthielten, wurden eingeschlossen. Das Verzerrungsrisiko wurde mithilfe der Newcastle-Ottawa Scale ermittelt. Die für die Forschungsfragen relevanten Artikel wurden inhaltlich analysiert. Ergebnisse Es wurden primär 48 Treffer generiert. Neun Artikel entsprachen den Einschlusskriterien und wurden analysiert. In 6 Arbeiten mit näheren Angaben zur injizierten Substanz war in 98 – 100% der Fälle Kortison verwendet worden. Die berichteten Infektions- und Revisionsraten waren mit Injektion höher als ohne. Das Verzerrungsrisiko der hier analysierten Studien war auf Grundlage der Ermittlung der Newcastle-Ottawa Scale eher gering. Das Risiko einer Infektion nach einer Injektion mit Kortison vor, während oder nach einer Operation war erhöht. Innerhalb von 2 Wochen vor Operation war eine Injektion in bis zu 8% der Fälle mit einer Infektion assoziiert. Innerhalb von 4 Wochen nach Operation war das Infektionsrisiko um bis zu 11-fach erhöht. Ebenso war das Risiko einer Revisionsoperation nach Injektion erhöht, wobei die zeitlichen Abstände zwischen Injektion und Operation zwischen den Studien teilweise differierten. Diskussion Lokale Infektionen und in geringerem Maße Revisionsoperationen sind mit perioperativen Injektionen (mit Kortison) innerhalb von 3 Monaten vor und bis 4 Wochen nach Operation assoziiert. Es lagen aber lediglich Datenbankanalysen von Versichertendaten mit mehreren Arbeiten aus wenigen Zentren vor. Somit konnten keine kausalen Zusammenhänge nachgewiesen werden. Aktuell kann aber bei vorsichtiger Herangehensweise Folgendes empfohlen werden: Der zeitliche Abstand zwischen Injektion mit Kortison vor Operation sollte mindestens 2 Wochen, besser 3 Monate betragen. Intraoperative Injektionen mit Kortison sind nicht empfehlenswert. Postoperativ sollte für mindestens 4 Wochen keine Injektion mit Kortison erfolgen. Wenn im Ausnahmefall von diesen zeitlichen Grenzen abgewichen wird, ist eine Aufklärung der Patienten über ein erhöhtes Risiko angezeigt
Motor Recovery of the Suprascapular Nerve after Arthroscopic Decompression in the Scapular Notch – a Systematic Review
No full textAbstract Background The suprascapular nerve can be compromised as a result of a compression syndrome in different locations. A (proximal) compression within the scapular notch can lead to dorsal shoulder pain and simultaneous weakness of the infraspinatus and supraspinatus muscles. By transection of the lig. transversum this compression syndrome can be treated. By means of a systematic review, the present work analyzes the motor recovery potential after arthroscopic decompression. Material and Methods A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The search words used were “suprascapular” and “arthroscopic”; “suprascapular” and “arthroscopy”. Based on the evaluated literature, articles in English with at least a partial arthroscopic case series from 4 cases on and a compression syndrome of the suprascapular nerve treated with arthroscopic decompression in the scapular notch were identified. Motor recovery was described by means of EMG, clinical strength and MRI. Results Primarily 408 hits were generated. Six articles met the inclusion criteria and were further analyzed. The number of arthroscopic cases was between 4 and a maximum of 27. The level of evidence was between III and IV. The majority of the reported clinical results were good. Motor recovery as measured by EMG was observed, recovery of full strength was not achieved in the majority of reported cases (60%), neither was regression of structural (fatty) degeneration of the muscle bellies. Conclusion Arthroscopic decompression of the suprascapular nerve in the scapular notch provides good clinical results and considerable pain relief. However, in the majority of cases it does not lead to a complete recovery of the strength of the supra- and infraspinatus muscles. Patients should be informed about this. An early decompression after diagnosis in the event of proximal compression within the suprascapular notch combined with beginning EMG or MRI changes appears reasonable. These beginning changes should be further defined. Future studies should develop prognostic criteria for motor recovery. Awareness regarding the diagnosis needs to be improved due to the probably time-dependent irreversibility of resulting muscular weakness.Zusammenfassung Hintergrund Der N. suprascapularis kann in seinem Verlauf an verschiedenen Stellen komprimiert werden. Ein (proximales) Kompressionssyndrom spezifisch in der Incisura scapulae führt häufig zu dorsalen Schulterschmerzen und zu einer simultanen Kraftabschwächung des Infraspinatus- und Supraspinatusmuskels. Durch Durchtrennung des Lig. transversum kann dieses Kompressionssyndrom behandelt werden. Die vorliegende Arbeit analysiert durch einen systematischen Review das motorische Erholungspotenzial nach arthroskopischer Dekompression. Material und Methoden Es wurde eine systematische Durchsicht der Datenbank der U. S. National Library of Medicine/National Institutes of Health (PubMed) und der Cochrane Library unter Anwendung der PRISMA-Checkliste durchgeführt. Als Suchwörter dienten „suprascapular“ und „arthroscopic“; „suprascapular“ und „arthroscopy“. Anhand der evaluierten Literatur wurden Artikel mit zumindest anteiligen arthroskopischen Fallserien ab 4 Fällen bei Kompressionssyndrom mit einer arthroskopischen Dekompression des N. suprascapularis in der Incisura scapulae in englischer Sprache identifiziert. Eine motorische Erholung des Nervs wurde beschrieben anhand von EMG, klinischem Kraftgrad und MRT. Ergebnisse Es wurden primär 408 Treffer generiert. Sechs Artikel entsprachen den Einschlusskriterien und wurden weitergehend inhaltlich analysiert. Die arthroskopische Fallzahl lag zwischen 4 und maximal 27. Der Evidenzlevel lag zwischen III und IV. Die berichteten klinischen Ergebnisse waren mehrheitlich gut. Eine motorische Erholung, gemessen mittels EMG, wurde beobachtet, eine Wiedererlangung des vollständigen Kraftgrades in der Mehrzahl der berichteten Fälle nicht (60%), eine Rückbildung von strukturellen (fettigen) Degenerationen der Muskelbäuche ebenso wenig. Diskussion Die arthroskopische Dekompression des N. suprascapularis in der Incisura scapulae sorgt für klinisch gute Ergebnisse und erhebliche Schmerzerleichterung. Sie führt in der Mehrzahl der Fälle aber nicht zu einer kompletten Erholung des Kraftgrades der Supra- und Infraspinatusmuskulatur. Hierüber sollten Patienten aufgeklärt werden. Eine frühe Dekompression bei klinischer Diagnose bei proximaler Kompression in der Incisura scapulae und leichten Veränderungen im EMG oder MRT erscheint sinnvoll. Diese beginnenden Veränderungen sollten weiter definiert werden. Zukünftige Studien sollten zudem prognostische Kriterien für das Erholungspotenzial des N. suprascapularis entwickeln. Die Awareness hinsichtlich der Diagnose muss wegen der wahrscheinlich zeitabhängigen Irreversibilität der Muskelschwäche erhöht werden.Abstract Background The suprascapular nerve can be compromised as a result of a compression syndrome in different locations. A (proximal) compression within the scapular notch can lead to dorsal shoulder pain and simultaneous weakness of the infraspinatus and supraspinatus muscles. By transection of the lig. transversum this compression syndrome can be treated. By means of a systematic review, the present work analyzes the motor recovery potential after arthroscopic decompression. Material and Methods A systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) database and the Cochrane Library was performed using the PRISMA checklist. The search words used were “suprascapular” and “arthroscopic”; “suprascapular” and “arthroscopy”. Based on the evaluated literature, articles in English with at least a partial arthroscopic case series from 4 cases on and a compression syndrome of the suprascapular nerve treated with arthroscopic decompression in the scapular notch were identified. Motor recovery was described by means of EMG, clinical strength and MRI. Results Primarily 408 hits were generated. Six articles met the inclusion criteria and were further analyzed. The number of arthroscopic cases was between 4 and a maximum of 27. The level of evidence was between III and IV. The majority of the reported clinical results were good. Motor recovery as measured by EMG was observed, recovery of full strength was not achieved in the majority of reported cases (60%), neither was regression of structural (fatty) degeneration of the muscle bellies. Conclusion Arthroscopic decompression of the suprascapular nerve in the scapular notch provides good clinical results and considerable pain relief. However, in the majority of cases it does not lead to a complete recovery of the strength of the supra- and infraspinatus muscles. Patients should be informed about this. An early decompression after diagnosis in the event of proximal compression within the suprascapular notch combined with beginning EMG or MRI changes appears reasonable. These beginning changes should be further defined. Future studies should develop prognostic criteria for motor recovery. Awareness regarding the diagnosis needs to be improved due to the probably time-dependent irreversibility of resulting muscular weakness.Zusammenfassung Hintergrund Der N. suprascapularis kann in seinem Verlauf an verschiedenen Stellen komprimiert werden. Ein (proximales) Kompressionssyndrom spezifisch in der Incisura scapulae führt häufig zu dorsalen Schulterschmerzen und zu einer simultanen Kraftabschwächung des Infraspinatus- und Supraspinatusmuskels. Durch Durchtrennung des Lig. transversum kann dieses Kompressionssyndrom behandelt werden. Die vorliegende Arbeit analysiert durch einen systematischen Review das motorische Erholungspotenzial nach arthroskopischer Dekompression. Material und Methoden Es wurde eine systematische Durchsicht der Datenbank der U. S. National Library of Medicine/National Institutes of Health (PubMed) und der Cochrane Library unter Anwendung der PRISMA-Checkliste durchgeführt. Als Suchwörter dienten „suprascapular“ und „arthroscopic“; „suprascapular“ und „arthroscopy“. Anhand der evaluierten Literatur wurden Artikel mit zumindest anteiligen arthroskopischen Fallserien ab 4 Fällen bei Kompressionssyndrom mit einer arthroskopischen Dekompression des N. suprascapularis in der Incisura scapulae in englischer Sprache identifiziert. Eine motorische Erholung des Nervs wurde beschrieben anhand von EMG, klinischem Kraftgrad und MRT. Ergebnisse Es wurden primär 408 Treffer generiert. Sechs Artikel entsprachen den Einschlusskriterien und wurden weitergehend inhaltlich analysiert. Die arthroskopische Fallzahl lag zwischen 4 und maximal 27. Der Evidenzlevel lag zwischen III und IV. Die berichteten klinischen Ergebnisse waren mehrheitlich gut. Eine motorische Erholung, gemessen mittels EMG, wurde beobachtet, eine Wiedererlangung des vollständigen Kraftgrades in der Mehrzahl der berichteten Fälle nicht (60%), eine Rückbildung von strukturellen (fettigen) Degenerationen der Muskelbäuche ebenso wenig. Diskussion Die arthroskopische Dekompression des N. suprascapularis in der Incisura scapulae sorgt für klinisch gute Ergebnisse und erhebliche Schmerzerleichterung. Sie führt in der Mehrzahl der Fälle aber nicht zu einer kompletten Erholung des Kraftgrades der Supra- und Infraspinatusmuskulatur. Hierüber sollten Patienten aufgeklärt werden. Eine frühe Dekompression bei klinischer Diagnose bei proximaler Kompression in der Incisura scapulae und leichten Veränderungen im EMG oder MRT erscheint sinnvoll. Diese beginnenden Veränderungen sollten weiter definiert werden. Zukünftige Studien sollten zudem prognostische Kriterien für das Erholungspotenzial des N. suprascapularis entwickeln. Die Awareness hinsichtlich der Diagnose muss wegen der wahrscheinlich zeitabhängigen Irreversibilität der Muskelschwäche erhöht werden
Arthroscopic Reconstruction of Intratendinous Lesions of the Supraspinatus Tendon – a Systematic Review
No full textAbstract
Background Intratendinous lesions of the rotator cuff of the shoulder are frequent and may be a distinct clinical entity. Nevertheless, there are only a few publications which deal specifically with this subject. This study analyses the existing literature for the arthroscopic reconstruction of the intratendinous lesion of the supraspinatus tendon, by means of a systematic review, and identifies relevant research questions for future studies.
Material and Methods In January 2017, a systematic review of the U. S. National Library of Medicine/National Institutes of Health (PubMed) Database and the Cochrane Library was conducted using the PRISMA checklist. The search words were “supraspinatus” and “interstitial”; “supraspinatus”, “tear” and “intratendinous”; “supraspinatus” and “concealed”. In the course of the review, articles written in English with at least a partial arthroscopic case series dealing with the reconstruction of the supraspinatus tendon were identified and further analysed.
Results Primarily 70 hits could be generated. Five articles met the inclusion criteria and were analysed in detail. The number of arthroscopic cases ranged between 6 and 33. Level of evidence was IV in all studies. The diagnosis of an intratendinous lesion was made by MR imaging when T2/fat-saturated sequences showed an intratendinous high intensity signal without disruption of the bursal or articular layer. Three different concepts were followed in surgical treatment: opening of the intratendinous lesion from the bursal or articular side or by complete resection of the lesion. The reconstruction was performed with suture anchors in all cases. In the majority of cases, an acromioplasty was also performed. The reported clinical results were mostly good. Healing of the tendon was shown by MR imaging in 81.5 to 100% of cases.
Conclusion After failure of conservative treatment, symptomatic intratendinous lesions of the supraspinatus tendon can be localised intraoperatively and reconstructed after failure of conservative treatment. The expected results are good in the medium term. The evidence level of the studies analysed was low. Future studies should examine the role of alternative conservative and surgical therapies.</jats:p
Restoration of the hip geometry after two-stage exchange with intermediate resection arthroplasty for periprosthetic joint infection
No full textAbstract Two-stage exchange with intermediate resection arthroplasty (RA) is a well-established surgical procedure in the treatment of chronic periprosthetic joint infection (PJI), whereby a higher failure rate of final hip geometry restoration due to tissue contraction is controversially discussed. The aim was to evaluate radiographic changes of hip geometry parameters during PJI treatment and to determine the impact of the intermediate RA on the final joint restoration after reimplantation of a total hip arthroplasty (reTHA). Radiographic parameters (leg length (LL), femoral offset (FO), horizontal/vertical acetabular center of rotation distance (h/vCORD)) of 47 patients (mean age: 64.1 years) were measured on standard radiographs of the pelvis and compared between four different stages during PJI treatment (pre-replacement status (preTHA), primary total hip arthroplasty (pTHA), RA and reTHA). The RA duration (mean: 10.9 months) and the number of reoperations during this period (mean: n = 2.0) as well as their impact on hip geometry restoration were evaluated. Between preTHA and pTHA/reTHA an equivalent restoration was measured regarding the FO ( p < 0.001/ p < 0.001) and hCORD ( p = 0.016/ p < 0.001), but not regarding the LL and vCORD. In contrast, analysis revealed no influence of RA and an equivalent reconstruction of LL ( p = 0.003), FO ( p < 0.001), v/hCORD ( p = 0.039/ p = 0.035) at reTHA compared to pTHA. Furthermore, RA duration ( p = 0.053) and the number of reoperations after RA ( p = 0.134) had no impact on radiographic hip geometry restoration. The two-stage exchange with intermediate RA does not alter the preexisting hip joint parameters, whereby a good restoration of the final hip geometry, independent of the duration or the number of reoperations, can be achieved
Vastus Medialis Obliquus Muscle Morphology in Primary and Recurrent Lateral Patellar Instability
No full textThe morphology of the vastus medialis obliquus (VMO) muscle in the anatomical setting of an unstable patella has not been described. Therefore, the purpose of this study was to investigate the morphological parameters of the VMO muscle that delineate its importance in the maintenance of patellofemoral joint stability. Eighty-two consecutive subjects were prospectively enrolled in this study. The groups were composed of thirty patients with an acute primary patellar dislocation, thirty patients with recurrent patellar dislocation, and twenty-two controls. Groups were adjusted according to sex, age, body mass index, and physical activity. Magnetic resonance imaging was used to measure the VMO cross-sectional area, muscle-fiber angulation, and the craniocaudal extent of the muscle in relation to the patella. No significant difference was found with respect to all measured VMO parameters between primary dislocation, recurrent dislocation, and control subjects with a trend noted for only the VMO cross-sectional area and the VMO muscle-fiber angulation. This finding is notable in that atrophy of the VMO has often been suggested to play an important role in the pathophysiology of an unstable patellofemoral joint
Sequential osseointegration from osseohealing to osseoremodeling - Histomorphological comparison of novel 3D porous and solid Ti-6Al-4V titanium implants
Full text linkIn the present study, we analyzed the
histological characteristics of osseointegration of an
open-porous Ti-6Al-4V material that was produced in a
space holder method creating a 3-D through-pores
trabecular design that mimics the inhomogeneity and
size relationships of trabecular bone in macro- as well as
microstructure. Pairs of cylindrical implants with a
porosity of 49% and an average pore diameter of 400
µm (PI) or equal sized solid, corundum blasted devices
(SI) as reference were bilaterally implanted press fit in
the lateral condyles of 16 rabbits. Histological
examination was performed after 4 weeks of short-term
osseohealing and 12 weeks of mid-term osseoremodeling and we summarized the criteria for
sequential osseointegration. After 4 weeks, osteoid had
already been largely replaced by mineralized woven
bone in both types of implants but was only represented
to a greater extent in the deeper pores of PI. The cortical
as well as trabecular region showed regular osseohealing
with excessive and spatially undirected formation of
immature woven bone. A dense bone mass was found in
the cortical area, while in the trabecular region the bone
mass was reduced distinctly, presenting large lacuna-like
recesses and a demarcating trabecular structure. The
pores near the implant surface contained more
mineralized woven bone than the deeper pores. After 12
weeks, the osseoremodeling was largely completed with
a physiological maturation to lamellar bone. The newly
formed bone mass increased for PI and SI compared to
the 4-week group and osteoid was only detectable in the
deeper pores. The inhomogeneous trabecular design of
the pores enables an excellent ingrowth of mineralized
lamellar bone after remodeling to a pore depth of 1800
µm, which proves a functional load transfer from the
surrounding bone into the implant. According to the
concept of osseointegration by Branemark and
Albrektsson, the histological evaluation confirms a
successful, superior osseointegration of the presented
porous properties improving long-term implant stability.
The presented study protocol allows an excellent
evaluation and comparison of the sequential
osseointegration from short-term osseohealing to midterm osseoremodeling
Osseointegration of a novel 3D porous Ti-6Al-4V implant material – Histomorphometric analysis in rabbits
Full text linkPorous structure properties are known to
conduct initial and long-term stability of titanium alloy
implants. This study aims to assess the
histomorphometric effect of a 3-D porosity in Ti-6Al-4V
implants (PI) on osseointegration in comparison to solid
Ti-6Al-4V implants (SI). The PI was produced in a
spaceholder method and sintering and has a pore size of
mean 400 µm (50 µm to 500 µm) and mimics human
trabecular bone. Pairs of PI and equal sized SI as
reference were bilaterally implanted at random in the
lateral femoral condyle of 16 Chinchilla-Bastard rabbits.
The animals were sacrificed after 4 and 12 weeks for
histomorphometric analysis. The histomorphometric
evaluation confirmed a successful short-term
osseohealing (4 weeks) and mid-term osseoremodeling
(12 weeks) for both types of implants. The total newly
formed bone area was larger for PI than for SI after 4
and 12 weeks, with the intraporous bone area being
accountable for the significant difference (p<0.05). A
more detailed observation of bone area distribution
revealed a bony accumulation in a radius of ±500 µm
around the implant surface after remodeling. The boneto-implant contact (BIC) increased significantly (p<0.05)
from 4 to 12 weeks (PI 26.23% to 42.68%; SI 28.44% to
47.47%) for both types of implants. Due to different
surface properties, however, PI had a significant
(p<0.05) larger absolute osseous contact (mm) to the
implant circumference compared to the SI (4 weeks:
7.46 mm vs 5.72 mm; 12 weeks: 11.57 mm vs 9.52 mm
[PI vs. SI]). The regional influences (trabecular vs.
cortical) on bone formation and the intraporous
distribution were also presented. Conclusively, the
porous structure and surface properties of PI enable a
successful and regular osseointegration and enhance the
bony fixation compared to solid implants under
experimental conditions
Biomechanical evaluation of self-cinching stitch techniques in rotator cuff repair: The single-loop and double-loop knot stitches
No full textOpen-Access-Publikationsfonds 202
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