PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-9 (9)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  A CT scan protocol for the detection of radiographic loosening of the glenoid component after total shoulder arthroplasty 
Acta Orthopaedica  2014;85(1):91-96.
Background and purpose
It is difficult to evaluate glenoid component periprosthetic radiolucencies in total shoulder arthroplasties (TSAs) using plain radiographs. This study was performed to evaluate whether computed tomography (CT) using a specific patient position in the CT scanner provides a better method for assessing radiolucencies in TSA.
Methods
Following TSA, 11 patients were CT scanned in a lateral decubitus position with maximum forward flexion, which aligns the glenoid orientation with the axis of the CT scanner. Follow-up CT scanning is part of our routine patient care. Glenoid component periprosthetic lucency was assessed according to the Molé score and it was compared to routine plain radiographs by 5 observers.
Results
The protocol almost completely eliminated metal artifacts in the CT images and allowed accurate assessment of periprosthetic lucency of the glenoid fixation. Positioning of the patient within the CT scanner as described was possible for all 11 patients. A radiolucent line was identified in 54 of the 55 observed CT scans and osteolysis was identified in 25 observations. The average radiolucent line Molé score was 3.4 (SD 2.7) points with plain radiographs and 9.5 (SD 0.8) points with CT scans
(p = 0.001). The mean intra-observer variance was lower in the CT scan group than in the plain radiograph group (p = 0.001).
Interpretation
The CT scan protocol we used is of clinical value in routine assessment of glenoid periprosthetic lucency after TSA. The technique improves the ability to detect and monitor radiolucent lines and, therefore, possibly implant loosening also.
doi:10.3109/17453674.2013.869653
PMCID: PMC3940998  PMID: 24286563
2.  Accuracy of Glenoid Component Placement in Total Shoulder Arthroplasty and Its Effect on Clinical and Radiological Outcome in a Retrospective, Longitudinal, Monocentric Open Study 
PLoS ONE  2013;8(10):e75791.
Background
The success of Total Shoulder Arthroplasty (TSA) is believed to depend on the restoration of the natural anatomy of the joint and a key development has been the introduction of modular humeral components to more accurately restore the patient’s anatomy. However, there are no peer-reviewed studies that have reported the degree of glenoid component mal-position achieved in clinical practice and the clinical outcome of such mal-position. The main purpose of this study was to assess the accuracy of glenoid implant positioning during TSA and to relate it to the radiological (occurrence of radiolucent lines and osteolysis on CT) and clinical outcomes.
Methods
68 TSAs were assessed with a mean follow-up of 38+/−27 months. The clinical evaluation consisted of measuring the mobility as well as of the Constant Score. The radiological evaluation was performed on CT-scans in which metal artefacts had been eliminated. From the CT-scans radiolucent lines and osteolysis were assessed. The positions of the glenoid and humeral components were also measured from the CT scans.
Results
Four position glenoid component parameters were calculated The posterior version (6°±12°; mean ± SD), the superior tilt (12°±17°), the rotation of the implant relative to the scapular plane (3°±14°) and the off-set distance of the centre of the glenoid implant from the scapular plane (6±4 mm). An inferiorly inclined implant was found to be associated with higher levels of radiolucent lines while retroversion and non-neutral rotation were associated with a reduced range of motion.
Conclusion
this study demonstrates that glenoid implants of anatomic TSA are poorly positioned and that this malposition has a direct effect on the clinical and radiological outcome. Thus, further developments in glenoid implantation techniques are required to enable the surgeon to achieve a desired implant position and outcome.
doi:10.1371/journal.pone.0075791
PMCID: PMC3793002  PMID: 24116075
3.  Total shoulder arthroplasty does not correct the orientation of the eroded glenoid 
Acta Orthopaedica  2012;83(5):529-535.
Background and purpose
Alignment of the glenoid component with the scapula during total shoulder arthroplasty (TSA) is challenging due to glenoid erosion and lack of both bone stock and guiding landmarks. We determined the extent to which the implant position is governed by the preoperative erosion of the glenoid. Also, we investigated whether excessive erosion of the glenoid is associated with perforation of the glenoid vault.
Methods
We used preoperative and postoperative CT scans of 29 TSAs to assess version, inclination, rotation, and offset of the glenoid relative to the scapula plane. The position of the implant keel within the glenoid vault was classified into three types: centrally positioned, component touching vault cortex, and perforation of the cortex.
Results
Preoperative glenoid erosion was statistically significantly linked to the postoperative placement of the implant regarding all position parameters. Retroversion of the eroded glenoid was on average 10° (SD10) and retroversion of the implant after surgery was 7° (SD11). The implant keel was centered within the vault in 7 of 29 patients and the glenoid vault was perforated in 5 patients. Anterior cortex perforation was most frequent and was associated with severe preoperative posterior erosion, causing implant retroversion.
Interpretation
The position of the glenoid component reflected the preoperative erosion and “correction” was not a characteristic of the reconstructive surgery. Severe erosion appears to be linked to vault perforation. If malalignment and perforation are associated with loosening, our results suggest reorientation of the implant relative to the eroded surface.
doi:10.3109/17453674.2012.733916
PMCID: PMC3488182  PMID: 23083436
4.  Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system 
Background
Studies published in the 1970s by Mostafa S. Fahim and colleagues showed that a short treatment with ultrasound caused the depletion of germ cells and infertility. The goal of the current study was to determine if a commercially available therapeutic ultrasound generator and transducer could be used as the basis for a male contraceptive.
Methods
Sprague-Dawley rats were anesthetized and their testes were treated with 1 MHz or 3 MHz ultrasound while varying power, duration and temperature of treatment.
Results
We found that 3 MHz ultrasound delivered with 2.2 Watt per square cm power for fifteen minutes was necessary to deplete spermatocytes and spermatids from the testis and that this treatment significantly reduced epididymal sperm reserves. 3 MHz ultrasound treatment reduced total epididymal sperm count 10-fold lower than the wet-heat control and decreased motile sperm counts 1,000-fold lower than wet-heat alone. The current treatment regimen provided nominally more energy to the treatment chamber than Fahim's originally reported conditions of 1 MHz ultrasound delivered at 1 Watt per square cm for ten minutes. However, the true spatial average intensity, effective radiating area and power output of the transducers used by Fahim were not reported, making a direct comparison impossible. We found that germ cell depletion was most uniform and effective when we rotated the therapeutic transducer to mitigate non-uniformity of the beam field. The lowest sperm count was achieved when the coupling medium (3% saline) was held at 37 degrees C and two consecutive 15-minute treatments of 3 MHz ultrasound at 2.2 Watt per square cm were separated by 2 days.
Conclusions
The non-invasive nature of ultrasound and its efficacy in reducing sperm count make therapeutic ultrasound a promising candidate for a male contraceptive. However, further studies must be conducted to confirm its efficacy in providing a contraceptive effect, to test the result of repeated use, to verify that the contraceptive effect is reversible and to demonstrate that there are no detrimental, long-term effects from using ultrasound as a method of male contraception.
doi:10.1186/1477-7827-10-7
PMCID: PMC3340307  PMID: 22289508
Male contraception; therapeutic ultrasound; testis; epididymis; wet-heat
5.  Screening and surveillance for second malignant neoplasms in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study (CCSS) 
Annals of internal medicine  2010;153(7):442-451.
Background
Childhood cancer survivors may develop a second malignant neoplasm during adulthood and therefore require regular surveillance.
Objective
To examine adherence to population cancer screening guidelines by survivors at average risk of developing a second malignant neoplasm, and to cancer surveillance guidelines by survivors at high risk of developing a second malignant neoplasm.
Design
Retrospective cohort study.
Setting
The Childhood Cancer Survivor Study (CCSS), a 26 center study of long-term survivors of childhood cancer who were diagnosed between 1970 and 1986.
Patients
4,329 male and 4,018 female survivors of childhood cancer who completed a CCSS questionnaire assessing screening and surveillance for new cancers.
Measurements
Patient-reported receipt and timing of mammography, Papanicolaou smear, colonoscopy, or skin examination was categorized as adherent to the United States Preventive Services Task Force guidelines for survivors at average risk for breast or cervical cancer, or the Children’s Oncology Group guidelines for survivors at high risk for developing breast, colorectal or skin cancer as a result of their therapy.
Results
Among average risk female survivors, 2,743/3,392 (80.9%) reported a Papanicolaou smear within the recommended period, and 140/209 (67.0%) reported a mammogram within the recommended period. Among high risk survivors, rates of recommended mammography among females, and colonoscopy and complete skin exams among both genders were only 241/522 (46.2%), 91/794 (11.5%) and 1,290/4,850 (26.6%), respectively.
Limitations
Data were self report. CCSS participants are a select group of survivors and their compliance may not be representative of all childhood cancer survivors.
Conclusions
Female survivors at average risk for developing a second malignant neoplasm demonstrate reasonable rates of screening for cervical and breast cancer. However, surveillance for new cancers is very poor amongst survivors at highest risk for colon, breast or skin cancer, suggesting that survivors and their physicians need education about their risks and the recommended surveillance.
doi:10.1059/0003-4819-153-7-201010050-00007
PMCID: PMC3084018  PMID: 20921543
6.  CHANGES IN LIPID-ENCAPSULATED MICROBUBBLE POPULATION DURING CONTINUOUS INFUSION AND METHODS TO MAINTAIN CONSISTENCY 
Ultrasound in medicine & biology  2009;35(10):1748-1755.
Stabilized microbubbles are utilized as ultrasound contrast agents. These micron-sized gas capsules are injected into the bloodstream to provide contrast enhancement during ultrasound imaging. Some contrast imaging strategies, such as destruction-reperfusion, require a continuous injection of microbubbles over several minutes. Most quantitative imaging strategies rely on the ability to administer a consistent dose of contrast agent. Because of the buoyancy of these gas-filled agents, their spatial distribution within a syringe changes over time. The population of microbubbles that is pumped from a horizontal syringe outlet differs from initial population as the microbubbles float to the syringe top. In this manuscript, we study the changes in the population of a contrast agent that is pumped from a syringe due to microbubble floatation. Results are presented in terms of change in concentration and change in mean diameter, as a function of time, suspension medium, and syringe diameter. Data illustrate that the distribution of contrast agents injected from a syringe changes in both concentration and mean diameter over several minutes without mixing. We discuss the application of a mixing system and viscosity agents to keep the contrast solution more evenly distributed in a syringe. These results are significant for researchers utilizing microbubble contrast agents in continuous-infusion applications where it is important to maintain consistent contrast agent delivery rate, or in situations where the injection syringe cannot be mixed immediately prior to administration.
doi:10.1016/j.ultrasmedbio.2009.04.023
PMCID: PMC2752484  PMID: 19632760
Microbubbles; Contrast Agent; Ultrasound; Size Distribution; Concentration; Mixing; Floatation; Rotating Syringe
7.  Measurement of femoral head penetration in polyethylene using a 3-dimensional CT-scan technique 
Acta Orthopaedica  2010;81(5):563-569.
Background
Current techniques for measuring in vivo polyethylene wear suffer from a range of problems, resulting in an unacceptable lack of repeatability and/or insufficient accuracy when they are used to measure the low wear rates associated with new, highly crosslinked polyethylene. We describe an improved CT method for measurement of 3D femoral head penetration in PE acetabular cups that has sufficient accuracy and repeatability to allow assessment of the wear potential of modern implants.
Method
The accuracy and repeatability of the CT-scan method was determined by blindly repeating measurements on a precisely calibrated 28-mm prosthetic head and by comparing them with direct metrological measurements on 10 acetabular specimens with in vitro wear from machining, and on 8 explanted acetabular specimens with in vivo wear.
Results
The intra- and interobserver errors in femoral head diameter were 0.036 mm (SD 0.044) and 0.050 mm (SD 0.022), respectively. CT estimated femoral head penetration in both all-poly and metal-backed acetabular components with accuracy ranging from 0.009 to 0.245 mm (mean 0.080; SD 0.067).
Interpretation
We found that the CT method is rapid, is accurate, and has repeatability and ease of availability. Using a slice thickness of 0.0625 mm, this method can detect wear—and also the threshold for the wear rate that causes osteolysis—much earlier than previous methods.
doi:10.3109/17453674.2010.519163
PMCID: PMC3214744  PMID: 20860445
8.  Case report of an acquired factor XIII inhibitor: diagnosis and management 
A 57-year-old man presented with a spontaneous upper-extremity hematoma and compartment syndrome. The patient experienced excessive bleeding following evacuation of the hematoma, and the results of routine coagulation studies were normal. Factor XIII activity was undetectable using a photometric assay, and the presence of an inhibitor was detected with mixing studies. Bleeding was controlled with infusions of fresh frozen plasma and cryoprecipitate. Cyclophosphamide was started on the 16th hospital day, and four weekly doses of the monoclonal anti-CD20 antibody, rituximab, were begun 3 weeks later. One week after the initial dose of rituximab, the inhibitor was no longer detectable and the factor XIII level increased to 28%. After completion of the rituximab therapy, the factor XIII activity was 58% with no inhibitor present. This case illustrates the need to check for unusual defects such as factor XIII deficiency if a bleeding tendency is evident—even if routine studies are unrevealing.
PMCID: PMC1484527  PMID: 17252037
9.  OUR INDICTMENT OF GERMANY 
PMCID: PMC1593721  PMID: 18737489

Results 1-9 (9)