[Show abstract][Hide abstract] ABSTRACT: The discovery of regenerative and immunosuppressive capacities of mesenchymal stromal cells (MSCs) raises hope for patients with tissue-damaging or severe, treatment-refractory autoimmune disorders. We previously presented a method to expand human MSCs in a bioreactor under standardized Good Manufacturing Practice conditions. Now we characterized the impact of critical treatment conditions on MSCs with respect to immunosuppressive capabilities and proliferation.MethodsMSC proliferation and survival after γ irradiation were determined by 5-carboxyfluorescein diacetate N-succinimidyl ester and annexinV/4′,6-diamidino-2-phenylindole (DAPI) staining, respectively. T-cell proliferation assays were used to assess the effect of γ irradiation, passaging, cryopreservation, post-thaw equilibration time and hypoxia on T-cell suppressive capacities of MSCs. Quantitative polymerase chain reaction and β-galactosidase staining served as tools to investigate differences between immunosuppressive and non-immunosuppressive MSCs.Resultsγ irradiation of MSCs abrogated their proliferation while vitality and T-cell inhibitory capacity were preserved. Passaging and long cryopreservation time decreased the T-cell suppressive function of MSCs, and postthaw equilibration time of 5 days restored this capability. Hypoxic culture markedly increased MSC proliferation without affecting their T-cell-suppressive capacity and phenotype. Furthermore, T-cell suppressive MSCs showed higher CXCL12 expression and less β-galactosidase staining than non-suppressive MSCs.DiscussionWe demonstrate that γ irradiation is an effective strategy to abrogate MSC proliferation without impairing the cells' immunosuppressive function. Hypoxia significantly enhanced MSC expansion, allowing for transplantation of MSCs with low passage number. In summary, our optimized MSC expansion protocol successfully addressed the issues of safety and preservation of immunosuppressive MSC function after ex vivo expansion for therapeutic purposes.
[Show abstract][Hide abstract] ABSTRACT: Implant-associated osteomyelitis still represents a demanding challenge due to unfavourable biological conditions, bacterial properties and incremental resistance to antibiotic treatment. Therefore different bactericide or bacteriostatic implant coatings have been developed recently to control local intramedullary infections. Controlled local release of gentamicin base from a highly lipophilic gentamicin palmitate compound achieves extended intramedullary retention times and thus may improve its bactericide effect.
International Orthopaedics 11/2014; · 2.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Modular bicompartmental knee arthroplasty (BKA) for treatment of medio-patellofemoral osteoarthritis (OA) should allow for close to normal kinematics in comparison with unicondylar knee arthroplasty (UKA) and the native knee. There is so far no data to support this.
The Knee 09/2014; 21 Suppl 1:S3-9. · 2.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report on three children with bilateral, congenital clubfoot. Four of the six clubfeet were associated with preaxial polydactyly. Five of the six clubfeet were treated without extensive surgery. A plantigrade foot was achieved, even in the three clubfeet with polydactyly, using serial casting and percutaneous Achilles tenotomy. Casting was adapted according to the existing polydactyly. One case with tibial hemimelia and a complex clubfoot deformity with preaxial tarsal polydactyly required more comprehensive surgery. A foot with good weight-bearing function was also achieved in this case following resection of the accessory medial ray, including resection of the accessory tarsal bones and posterior release. Remaining limitations in mobility were ascribed to hindfoot pathologies.
Journal of Pediatric Orthopaedics B 07/2014; · 0.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chondrosarcoma is one of the most common malignant bone tumours in adults. However, it rarely occurs during pregnancy. Therefore, reports on surgical and medical management of this entity are hard to find. Different studies suggest a possible growth-enhancing effect of altered hormone levels on various bone tumours. The effect of pregnancy on growth characteristics of chondrosarcomas however remains unclear. We report a case of a 32-year-old pregnant woman with a newly occurred chondrosarcoma of the tibial head. Intense clinical monitoring and repeated MRI scans showed a tumour progression during pregnancy followed by the need of above-knee amputation after 30 weeks gestation. Spontaneous vaginal delivery after 38 weeks gestation was complicated by an amniotic infection syndrome and finally stopped, necessitating a caesarean section. Despite this there were no further complications to be mentioned. No local tumour recurrence or metastases could be detected in the staging CT scans following pregnancy.
[Show abstract][Hide abstract] ABSTRACT: Background: Since 1985 the hips of the newborns have been sonographically screened at the University Hospital Marburg by staff of the Orthopaedic Department. This study was conducted to collect data on the local incidence of DDH (developmental dysplasia of the hip). Moreover, the diagnostic findings were checked critically to detect weak points. Another aim was to analyse the influence of investigators' experience on the treatment recommendation. Material and Methods: In a retrospective study, 18 247 hip sonograms in a treatment period from 1985 to 2009 were analysed. The following parameters were evaluated: perinatal incidents (e.g., breech presentation, Caesarean section, premature delivery), orthopaedic findings (e.g., club foot, limitation of hip abduction). Bony roof, superior bony rim and cartilaginous roof were analysed; α- and β-angles and hip type according to Graf were documented. Comparisons between variables were calculated by means of adequate statistic tests. χ(2)-values and coefficients of correlation were used to detect significance. Results: All in all 55 physicians of our Orthopaedic Department conducted 350 measurements on average (min. 1; max. 1993). Accuracy of documentation improved over time. In particular in the beginning of the screening, the hip angles according to Graf were not completely determined and sonograms were classified by "visual diagnosis". The β-angle was not measured at the outset. In the course of time we measured a decrease of the diagnosis hip type II a according to Graf. In the years 1985-1989 more than 40 % of the hips were described as physiologically immature. We evaluated a numerical regression of hip type II a to 16 % in time period 1990-1994 and 9 % in time period 2005-2009. There was a significant correlation between breech presentation and decentering and eccentric hips. Inexperienced physicians recommend more often therapeutic interventions (p ≤ 0.01). Treatment of hip type II a according to Graf was inconsistent over time. Conclusion: This study demonstrates the necessity of standardised hip sonography. Treatment according to measured hip type should be concise. Training programmes both for instructors and medical assistant staff is mandatory. "Bedside teaching" is not constructive.
[Show abstract][Hide abstract] ABSTRACT: Meniscal injury resulting in segmental loss of meniscal tissue is a major risk factor for the development of osteoarthritis. Tissue engineering strategies have provided scaffolds for meniscal regeneration in order to establish a treatment option for patients with limited opportunities for meniscal reconstruction. The purpose of this study was to assess the clinical and magnetic resonance imaging (MRI) results 2 years after implantation of a polyurethane scaffold for chronic segmental medial meniscus deficiency following partial medial meniscectomy.
Eighteen patients were treated with arthroscopic implantation of an ActiFit(®) (Orteq Sports Medicine) polyurethane meniscal scaffold for meniscus deficiency of the medial meniscus. Patients were followed up at 6, 12, and 24 months. Clinical outcome was assessed using patient-reported outcome scores (KOOS, KSS, UCLA activity scale, VAS for pain). Radiological outcome was assessed using MRI at 6, 12, and 24 months by evaluating scaffold morphology, scaffold integration, and additional joint injury, as well as joint inflammation.
Eighteen patients with a median age of 32.5 years (range 17-49) were enrolled. Statistically significant improvements were present in all patients, but one at 2 years compared to baseline in all categories. Complete resorption of the scaffold occurred in one patient representing a failure to treatment. MRI showed abnormal signal intensity of the scaffold when compared to residual meniscal tissue but without synovitis or joint inflammation. Extrusion of the scaffold was present in four patients. No correlation between scaffold extrusion and clinical outcome was observed.
Arthroscopic implantation of a polyurethane meniscal scaffold in patients with chronic segmental medial meniscus deficiency is not only a safe procedure but leads to good clinical results at a 2-year follow-up. Scaffold extrusion did not appear to affect clinical outcome. LEVEL OF EVIDENCE: IV.
Knee Surgery Sports Traumatology Arthroscopy 04/2014; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study was conducted to evaluate the current status of pediatric hip sonography at German university hospitals.
A questionnaire was sent to all heads of orthopedic departments in Germany. They were asked to give details of the technique and instrumentation used for hip ultrasound examination, local organization of consultation and options for advanced training of students and staff.
The return rate of the questionnaires was 93.9 %. Pediatric hip ultrasonography was performed at every university hospital by staff of the orthopedic and trauma departments (n = 31, 100 %). A well-established tradition of teaching both medical students and physicians on this topic was reported by many departments. Courses with a focus on pediatric hip sonography were organized in 25.8 % of the German university hospitals. In the majority of the responding orthopedic and trauma departments a 7.5 MHz linear transducer for ultrasound examination (93.5 %), a foot switch for rapid freezing of the ultrasound image (93.5 %) and a cradle for positioning the infant (100 %) were used. A guided probe device recommended by Graf was only used in 35.5 % of the departments. Evaluation of the sonograms was performed in 19 of the clinics (61.3 %) in the classical way on printed paper strips.
This survey documented the high importance of pediatric hip sonography in German university hospitals. Quality controls in the orthopedic departments are carried out internally. For this reason both the implementation of standardized training courses and the schooling of well-trained instructors are mandatory.
[Show abstract][Hide abstract] ABSTRACT: Diese Erhebung soll den aktuellen Stand und den Stellenwert der Sonographie der Säuglingshüfte an den deutschen Universitätskliniken aufzeigen.Anhand eines an die orthopädischen Lehrstuhlinhaber adressierten Fragebogens wurden die Art der apparativ-technischen Durchführung der Untersuchung, der Organisierungsgrad der Klinik und die Organisation der Sprechstunde eruiert. Erfragt wurde auch die Möglichkeit der Fort- und Weiterbildung für Ärzte und Medizinstudenten.Bei 33 angeschriebenen Kliniken betrug die Rücklaufquote der Fragebögen 93,9 %. Die Durchführung der sonographischen Untersuchung der Säuglingshüfte erfolgt an allen Universitätsklinken durch die Fachabteilung Orthopädie bzw. Orthopädie/Unfallchirurgie (n = 31; 100 %). Fort- und Weiterbildung der ärztlichen Mitarbeiter und Lehre der Medizinstudenten bzgl. dieses Themengebiets sind an vielen Standorten fest verankert. Sonographiekurse zur Säuglingshüfte werden an 25,8 % der orthopädischen Universitätskliniken organisiert. Standardmäßig verwendet werden ein 7,5-MHz-Linearschallkopf (93,5 %), ein Fußschalter zum schnellen Fixieren des Ultraschallbilds (93,5 %), eine Lagerungsschiene zur Positionierung des Säuglings (100 %). Die von Graf empfohlene Schallkopfführungsapparatur findet lediglich an 35,5 % der Kliniken Verwendung. Die Auswertung des erstellten Ultraschallbilds erfolgt an 19 der befragten Kliniken (61,3 %) klassisch auf ausgedruckten Papierstreifen.Die Sonographie der Säuglingshüfte besitzt einen hohen Stellenwert an den deutschen orthopädischen Universitätskliniken. Die Qualitätskontrolle an den Kliniken erfolgt intern. Hiefür sind strukturierte Ausbildungskurse und auch qualitativ gut ausgebildete Ausbilder an den einzelnen Kliniken erforderlich.
Der Orthopäde 02/2014; 43(2). · 0.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is assumed that unicondylar knee arthroplasty (UKA) features kinematics close to the natural knee. Clinical studies have also shown functional benefits for UKA. There is to date only little biomechanical data to support or explain these findings. The purpose of this study was to investigate whether UKA is able to preserve natural knee kinematics or not.
Six fresh frozen full leg cadaver specimens were prepared to be mounted in a kinematic rig with six degrees of freedom for the knee joint. Three motion patterns were applied before and after medial UKA: passive flexion-extension, open chain extension, and squatting. During the loaded motions, quadriceps and hamstrings muscle forces were applied. Infrared cameras continuously recorded the trajectories of marker frames rigidly attached to femur, tibia, and patella. Prior computer tomography allowed identification of coordinate frames of the bones and calculations of anatomical rotations and translations.
Native kinematics was reproduced after UKA in all the specimens. In the unloaded knee and during open chain extension, femoral rollback patterns after UKA were very close to those in the native knee. During squatting, the medial femoral condyle after UKA tended to be more posterior and superior with flexion and there was less tibial internal rotation. The tibia was found to be more in valgus after UKA during all motion patterns.
As ligaments, lateral compartment and patellofemoral anatomy are preserved with UKA; the unloaded knee closely resembles native kinematics. The slight kinematic changes that were found under load are probably due to loss of the conforming medial meniscus and to the mismatch in geometry and stiffness introduced by UKA. These patterns resemble those found in knees with significant loss of function of the medial meniscus.
Knee Surgery Sports Traumatology Arthroscopy 11/2013; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This pilot study used magnet resonance imaging (MRI) to analyse the rotation of medial unicondylar knee arthroplasty (UKA) components and assessed how accurately the results could be reproduced.
Knee MRI using a special protocol to reduce metal artefact was performed in ten patients who had undergone medial UKA. Two independent investigators measured the rotation angle of femoral (zirconium) and tibial (cemented full-poly or cemented modular metal-backed) components applying different reference lines for the latter. Statistical analysis comprised tests for reliability, variance between measurement techniques, standard deviations and limits of agreement.
For all methods tested, there was sufficient inter- and intra-observer reliability. Lowest variances were, however, found for the femoral epicondyles, for both femoral and tibial components. A tangent to the dorsal epicondyles of the tibia also gave reproducible results with low variances for the tibial component.
Almost all applied measurement techniques were reproducible by statistical definition, although some of them resulted in substantial differences between both, observations and observers. A variance test helps to distinguish better between clinically useful and less accurate references.
MRI allows good reproducible rotation analysis via the femoral epicondyles for both femoral and tibial UKA implants. For the tibia, the tibial tuberosity, the eminentia and the tibial epicondyles in particular were shown to be less reliable. The dorsal epicondyles seem to be most suitable for the tibial component.
Archives of Orthopaedic and Trauma Surgery 08/2013; · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:Lumbar facet joint degeneration is a source of chronic low back pain, with an incidence of 15% to 45% among patients with low back pain. Various therapeutic techniques in the treatment of facet-related pain have been described in the literature, including intraarticular lumbar facet joint steroid injections and radiofrequency denervation. In this study, we compared the effectiveness of intraarticular facet joint steroid injections and radiofrequency denervation.METHODS:Our randomized, double-blind, controlled study included patients who received intraarticular steroid infiltrations in the lumbar facet joints (L3/L4-L5/S1) and patients who underwent radiofrequency denervation of L3/L4-L5/S1 segments. The inclusion criteria were based first on magnetic resonance imaging findings showing hypertrophy of the facet joints L3/L4-L5/S1 and a positive response to an intraarticular test infiltration of the facet joints L3/L4-L5/S1 with local anesthetics. The primary end point was the Roland-Morris Questionnaire. Secondary end points were the visual analog scale and the Oswestry Disability Index. All outcome assessments were performed at baseline and at 6 months.RESULTS:Fifty-six patients were randomized; 24 of 29 patients in the steroid injection group and 26 of 27 patients in the denervation group completed the 6-month follow-up. Pain relief and functional improvement were observed in both groups. There were no significant differences between the 2 groups for the primary end point (95% confidence interval [CI], -3 to 4) and for both secondary end points (95% CI for visual analog scale, -2 to 1; 95% CI for Oswestry Disability Index, -18 to 0).CONCLUSIONS:Intraarticular steroid infiltration or radiofrequency denervation appear to be a managing option for chronic function-limiting low back pain of facet origin with favorable short- and midterm results in terms of pain relief and function improvement, but improvements were similar in both groups.
Anesthesia and analgesia 04/2013; · 3.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Assessment of shoulder mobility is essential for diagnosis and clinical follow-up of shoulder diseases. Only a few highly sophisticated instruments for objective measurements of shoulder mobility are available. The recently introduced DynaPort MiniMod TriGyro ShoulderTest-System (DP) was validated earlier in laboratory trials. We aimed to assess the precision (repeatability) and agreement of this instrument in human subjects, as compared to the conventional goniometer. METHODS: The DP is a small, light-weight, three-dimensional gyroscope that can be fixed on the distal upper arm, recording shoulder abduction, flexion, and rotation. Twenty-one subjects (42 shoulders) were included for analysis. Two subsequent assessments of the same subject with a 30-minute delay in testing of each shoulder were performed with the DP in two directions (flexion and abduction), and simultaneously correlated with the measurements of a conventional goniometer. All assessments were performed by one observer. Repeatability for each method was determined and compared as the statistical variance between two repeated measurements. Agreement was illustrated by Bland-Altman-Plots with 95% limits of agreement. Statistical analysis was performed with a linear mixed regression model. Variance for repeated measurements by the same method was also estimated and compared with the likelihood-ratio test. RESULTS: Evaluation of abduction showed significantly better repeatability for the DP compared to the conventional goniometer (error variance: DP = 0.89, goniometer = 8.58, p = 0.025). No significant differences were found for flexion (DP = 1.52, goniometer = 5.94, p = 0.09). Agreement assessment was performed for flexion for mean differences of 0.27[degree sign] with 95% limit of agreement ranging from -7.97[degree sign] to 8.51[degree sign]. For abduction, the mean differences were 1.19[degree sign] with a 95% limit of agreement ranging from -9.07[degree sign] to 11.46[degree sign]. CONCLUSION: In summary, DP demonstrated a high precision even higher than the conventional goniometer. Agreement between both methods is acceptable, with possible deviations of up to greater than 10[degree sign]. Therefore, static measurements with DP are more precise than conventional goniometer measurements. These results are promising for routine clinical use of the DP.
[Show abstract][Hide abstract] ABSTRACT: Purpose
The present study was designed to evaluate the penetration of diclofenac sodium 4 % spray gel in synovial tissue, synovial fluid and blood plasma after topical application in subjects with joint effusions and planned total knee arthroplasty (TKA) due to osteoarthritis.
A total of 39 patients were randomised to two- or three-times daily application of diclofenac sodium 4 % spray gel to knees requiring surgery over a treatment period of 3 days. Within 8 h after the last application, TKA was conducted, and the diclofenac concentrations in synovial tissue, synovial fluid and blood plasma were measured by liquid chromatography.
The median diclofenac concentration was approximately 10–20-fold higher in synovial tissue (36.2 and 42.8 ng/g) than in synovial fluid (2.6 and 2.8 ng/mL) or plasma (3.9 and 4.1 ng/mL) in both treatment groups. Dose proportionality for any compartment or treatment groups could not be detected. Treatment-related adverse events were noted in two cases and limited to skin reactions.
Diclofenac sodium 4 % spray gel was found to penetrate the skin locally in substantial amounts and thus reach the desired target tissue. Concentrations were not dose-dependent, and application was well tolerated by 97.4 % of patients. Topical application of diclofenac should be considered a valuable alternative to systemic NSAID therapy in the initial treatment of osteoarthritis.
Knee Surgery Sports Traumatology Arthroscopy 01/2013; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
The aim of this study is the presentation of the polyaxial locking NCB-plate in the treatment of femoral fractures, especially in elderly patients and in proximity of a prosthetic implant. The reduction and fixation of these fractures is a challenging surgical procedure with high complication rates reported up to 40%.
Patients and methods
A total of 72 patients with femoral fractures had polyaxial locking plate osteosynthesis. Indications included fractures of the shaft and around an implant. Concerning surgical procedures three different standardized techniques were performed: (1) minimally invasive with percutaneous distal insertion using a targeting device; (2) mini-open with additional cerclage wire via the same approach; (3) a conventional open reduction and internal fixation. Data collection included intraoperative data and early complications at 6, 24 and 52 weeks. Fifty-two patients had an implant or prosthesis in situ. Thirty-three patients were treated by technique (1), 32 patients had mini-open surgery and seven patients conventional open surgery.
Thirty-nine patients attended clinical follow-up after 52 weeks. Twenty-two patients were interviewed by telephone, two were untraceable and nine patients had died. Bony consolidation without secondary loss of reduction was confirmed after 52 weeks in all patients but two. Plate breakage occurred in these two at 25 and 31 weeks after surgery due to non-union. Implant related complications (17% in total) lead to surgical revision in five other cases: two deep wound infections as well as three minor revisions. When itemizing complications according to surgical technique used, most major complications occurred following open surgery.
The availability of polyaxial locking implants widened the range of indications for plate fixation in femoral fractures. The advantages of the polyaxial locking implant combined with minimally invasive surgical technique contribute to successful management of this population category. Early revision rate is noticeably lower compared to similar procedures.
Level of evidence
IV retrospective series.
Revue de Chirurgie Orthopédique et Traumatologique 11/2012; 98(7):695–696.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The aim of this study is the presentation of the polyaxial locking NCB-plate in the treatment of femoral fractures, especially in elderly patients and in proximity of a prosthetic implant. The reduction and fixation of these fractures is a challenging surgical procedure with high complication rates reported up to 40%. PATIENTS AND METHODS: A total of 72 patients with femoral fractures had polyaxial locking plate osteosynthesis. Indications included fractures of the shaft and around an implant. Concerning surgical procedures, three different standardized techniques were performed: (1) minimally invasive with percutaneous distal insertion using a targeting device; (2) mini-open with additional cerclage wire via the same approach and (3) a conventional open reduction and internal fixation. Data collection included intraoperative data and early complications at 6, 24 and 52 weeks. Fifty-two patients had an implant or prosthesis in situ. Thirty-three patients were treated by technique (1), 32 patients had mini-open surgery and seven patients conventional open surgery. RESULTS: Thirty-nine patients attended clinical follow-up after 52 weeks. Twenty-two patients were interviewed by telephone, two were untraceable and nine patients had died. Bony consolidation without secondary loss of reduction was confirmed after 52 weeks in all patients but two. Plate breakage occurred in these two at 25 and 31 weeks after surgery due to non-union. Implant related complications (17% in total) lead to surgical revision in five other cases: two deep wound infections as well as three minor revisions. When itemizing complications according to surgical technique used, most major complications occurred following open surgery. CONCLUSION: The availability of polyaxial locking implants widened the range of indications for plate fixation in femoral fractures. The advantages of the polyaxial locking implant combined with minimally invasive surgical technique contribute to successful management of this population category. Early revision rate is noticeably lower compared to similar procedures. LEVEL OF EVIDENCE: IV retrospective series.
Orthopaedics & Traumatology Surgery & Research 10/2012; · 1.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The reconstruction of large bone defects after injury or tumor resection often requires the use of bone substitution. Artificial scaffolds based on synthetic biomaterials can overcome disadvantages of autologous bone grafts, like limited availability and donor side morbidity. Among them, scaffolds based on nanofibers offer great advantages. They mimic the extracellular matrix, can be used as a carrier for growth factors and allow the differentiation of human mesenchymal stem cells. Differentiation is triggered by a series of signaling processes, including integrin and bone morphogenetic protein (BMP), which act in a cooperative manner. The aim of this study was to analyze whether these processes can be remodeled in artificial poly-(l)-lactide acid (PLLA) based nanofiber scaffolds in vivo. Electrospun matrices composed of PLLA-collagen type I or BMP-2 incorporated PLLA-collagen type I were implanted in calvarial critical size defects in rats. Cranial CT-scans were taken 4, 8 and 12 weeks after implantation. Specimens obtained after euthanasia were processed for histology and immunostainings on osteocalcin, BMP-2 and Smad5. After implantation the scaffolds were inhomogeneously colonized and cells were only present in wrinkle- or channel-like structures. Ossification was detected only in focal areas of the scaffold. This was independent of whether BMP-2 was incorporated in the scaffold. However, cells that migrated into the scaffold showed an increased ratio of osteocalcin and Smad5 positive cells compared to empty defects. Furthermore, in case of BMP-2 incorporated PLLA-collagen type I scaffolds, 4 weeks after implantation approximately 40 % of the cells stained positive for BMP-2 indicating an autocrine process of the ingrown cells. These findings indicate that a cooperative effect between BMP-2 and collagen type I can be transferred to PLLA nanofibers and furthermore, that this effect is active in vivo. However, this had no effect on bone formation. The reason for this seems to be an unbalanced colonization of the scaffolds with cells, due to insufficient pore size.
Journal of Materials Science Materials in Medicine 06/2012; 23(9):2227-33. · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ultrasonography of the hip has gained wide acceptance as reliable method for diagnosing developmental hip dysplasia in infants. This blinded study was conducted to investigate the influence of two linear probes with different frequency on diagnostic accuracy and reproducibility. In 206 consecutive newborns, the bony roof angle (α-angle) and cartilage roof angle (β-angle) were assessed by three investigators according to Graf. The hips were measured twice both with a 7.5 MHz and a 12 MHz linear transducer (Sonoline G60S(®) ultrasound system; Siemens, Erlangen, Germany). Each investigator evaluated his sonograms 6 weeks later. Depending on the mean values for α-angle and β-angle, the hips were classified. Reproducibility of the Graf classification was not found to be influenced. In two of three investigators, we observed significant improvement concerning variation of the β-angle with the 12 MHz probe. The use of high-resolution transmitters may improve diagnostic accuracy in ultrasonography of the newborn's hip.
Ultrasound in medicine & biology 05/2012; 38(7):1116-20. · 2.46 Impact Factor