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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.  Poly-S-Nitrosated Albumin as a Safe and Effective Multifunctional Antitumor Agent: Characterization, Biochemistry and Possible Future Therapeutic Applications 
BioMed Research International  2013;2013:353892.
Nitric oxide (NO) is a ubiquitous molecule involved in multiple cellular functions. Inappropriate production of NO may lead to disease states. To date, pharmacologically active compounds that release NO within the body, such as organic nitrates, have been used as therapeutic agents, but their efficacy is significantly limited by unwanted side effects. Therefore, novel NO donors with better pharmacological and pharmacokinetic properties are highly desirable. The S-nitrosothiol fraction in plasma is largely composed of endogenous S-nitrosated human serum albumin (Mono-SNO-HSA), and that is why we are testing whether this albumin form can be therapeutically useful. Recently, we developed SNO-HSA analogs such as SNO-HSA with many conjugated SNO groups (Poly-SNO-HSA) which were prepared using chemical modification. Unexpectedly, we found striking inverse effects between Poly-SNO-HSA and Mono-SNO-HSA. Despite the fact that Mono-SNO-HSA inhibits apoptosis, Poly-SNO-HSA possesses very strong proapoptotic effects against tumor cells. Furthermore, Poly-SNO-HSA can reduce or perhaps completely eliminate the multidrug resistance often developed by cancer cells. In this review, we forward the possibility that Poly-SNO-HSA can be used as a safe and effective multifunctional antitumor agent.
doi:10.1155/2013/353892
PMCID: PMC3893780  PMID: 24490156
3.  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
4.  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
5.  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
6.  S-Nitrosylated Human Serum Albumin-mediated Cytoprotective Activity Is Enhanced by Fatty Acid Binding* 
The Journal of Biological Chemistry  2008;283(50):34966-34975.
Binding of oleate to S-nitrosylated human serum albumin (SNO-HSA) enhances its cytoprotective effect on liver cells in a rat ischemia/reperfusion model. It enhances the antiapoptotic effect of SNO-HSA on HepG2 cells exposed to anti-Fas antibody. To identify some of the reasons for the increased cytoprotective effects, additional experiments were performed with glutathione and HepG2 cells. As indicated by 5,5′-dithiobis-2-nitrobenzoic acid binding, the addition of oleate increased the accessibility of the single thiol group of albumin. Binding of increasing amounts of oleate resulted in increasing and more rapid S-transnitrosation of glutathione. Likewise, binding of oleate, or of a mixture of endogenous fatty acids, improved S-denitrosation of SNO-HSA by HepG2 cells. Oleate also enhanced S-transnitrosation by HepG2 cells, as detected by intracellular fluorescence of diaminofluorescein-FM. All of the S-transnitrosation caused by oleate binding was blocked by filipin III. Oleate also increased, in a dose-dependent manner, the binding of SNO-HSA labeled with fluorescein isothiocyanate to the surface of the hepatocytes. A model in two parts was worked out for S-transnitrosation, which does not involve low molecular weight thiols. Fatty acid binding facilitates S-denitrosation of SNO-HSA, increases its binding to HepG2 cells and greatly increases S-transnitrosation by hepatocytes in a way that is sensitive to filipin III. A small nitric oxide transfer takes place in a slow system, which is unaffected by fatty acid binding to SNO-HSA and not influenced by filipin III. Thus, fatty acids could be a novel type of mediator for S-transnitrosation.
doi:10.1074/jbc.M807009200
PMCID: PMC2596408  PMID: 18940810
7.  An optimised method for quantifying glenoid orientation 
A robust quantification method is essential for inter-subject glenoid comparison and planning of total shoulder arthroplasty. This study compared various scapular and glenoid axes with each other in order to optimally define the most appropriate method of quantifying glenoid version and inclination.
Six glenoid and eight scapular axes were defined and quantified from identifiable landmarks of twenty-one scapular image scans. Pathology independency and insensitivity of each axis to inter-subject morphological variation within its region was tested. Glenoid version and inclination were calculated using the best axes from the two regions.
The best glenoid axis was the normal to a least-square plane fit on the glenoid rim, directed approximately medio-laterally. The best scapular axis was the normal to a plane formed by the spine root and lateral border ridge. Glenoid inclination was 15.7° ± 5.1° superiorly and version was 4.9° ± 6.1°, retroversion.
The choice of axes in the present technique makes it insensitive to pathology and scapular morphological variabilities. Its application would effectively improve inter-subject glenoid version comparison, surgical planning and design of prostheses for shoulder arthroplasty.
doi:10.4103/0973-6042.41407
PMCID: PMC2840818  PMID: 20300307
Version; inclination; morphology

Results 1-7 (7)