Previous studies have indicated an increased risk of periprosthetic joint infection (PJI) in patients treated with reverse shoulder arthroplasty (RSA) compared with patients treated with anatomic ...total shoulder arthroplasty. The reason for this is unclear but may be related to a high prevalence of previous rotator cuff repair in patients who are treated with RSA. The purpose of this study was to determine previous non-arthroplasty surgery as a risk factor for revision owing to PJI after RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis.
Data were retrieved from the Danish Shoulder Arthroplasty Registry and medical records. We included 2217 patients who underwent RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis between 2006 and 2019. PJI was defined as ≥3 of 5 tissue samples positive for the same bacteria or as definite or probable PJI evaluated based on criteria from the International Consensus Meeting. The Kaplan-Meier method was used to illustrate the unadjusted 14-year cumulative rates of revision. A Cox regression model was used to report hazard for revision owing to PJI. Results were adjusted for previous non-arthroplasty surgery, sex, diagnosis, and age.
Revision was performed in 88 shoulders (4.0%), of which 40 (1.8%) underwent revision owing to PJI. There were 272 patients (12.3%) who underwent previous rotator cuff repair, of whom 11 (4.0%) underwent revision owing to PJI. The 14-year cumulative rate of revision owing to PJI was 14.1% for patients with previous rotator cuff repair and 2.7% for patients without previous surgery. The adjusted hazard ratio for revision owing to PJI for patients with previous rotator cuff repair was 2.2 (95% confidence interval, 1.04-4.60) compared with patients without previous surgery.
There is an increased risk of revision owing to PJI after RSA for patients with previous rotator cuff repair. We recommend that patients with previous rotator cuff repair be regarded as high-risk patients when considering RSA.
Background and purpose - Osteoarthritis has become the most common indication for shoulder arthroplasty in Denmark, and the treatment strategies have changed towards the use of anatomical total ...shoulder arthroplasty and reverse shoulder arthroplasty. We investigated whether changes in the use of arthroplasty types have changed the overall patient-reported outcome from 2006 to 2015.
Patients and methods - We included 2,867 shoulder arthroplasties performed for osteoarthritis between 2006 and 2015 and reported to the Danish Shoulder Arthroplasty Registry. The Western Ontario Osteoarthritis of the Shoulder (WOOS) index at 1 year was used as patient-reported outcome. The raw score was converted to a percentage of a maximum score. General linear models were used to analyze differences in WOOS.
Results - The proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty increased from 3% and 7% in 2006 to 53% and 27% in 2015. The mean WOOS score was 70 (SD 26) after resurfacing hemiarthroplasties (n = 1,258), 68 (SD 26) after stemmed hemiarthroplasty (n = 500), 82 (SD 23) after anatomical total shoulder arthroplasties (n = 815), and 74 (SD 23) after reverse shoulder arthroplasties (n = 213). During the study period, the overall WOOS score increased with 18 (95% CI 12-22) in the univariate model and 10 (CI 5-15) in the multivariable model, and the WOOS scores for anatomical total shoulder arthroplasty increased by 14 (CI 5-23).
Interpretation - We found an increased WOOS score from 2006 to 2015, which was primarily related to a higher proportion of anatomical total shoulder arthroplasty and reverse shoulder arthroplasty towards the end of the study period, and to improved outcome of anatomical total shoulder arthroplasty.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Abstract
Background
Inferior scapular notching is a complication unique to reverse shoulder arthroplasty. The most efficient technique to avoid inferior scapular notching has been reported to be ...lateralization of the glenoid offset. This study aims to compare radiological and functional outcomes of the DELTA Xtend® Reverse Shoulder System Lateralized Glenosphere Line Extension (intervention group) with the Standard DELTA Xtend® Reverse Shoulder System (control group). We hypothesize that the lateralization improves the patient outcome by decreasing the risk of inferior scapular notching without increasing the risk of migration and loosening of glenoid component.
Methods
In this randomized controlled trial, all Danish citizens with rotator cuff arthropathy or degeneration of the glenohumeral joint with severe posterior wear and allocated for a reverse total shoulder arthroplasty at the department of orthopaedic surgery at Herlev and Gentofte Hospital, Copenhagen University Hospital, will be considered for participation. The exclusion criteria are as follows: below 50 years of age, cognitive or linguistic impairment, insufficient glenoid bone stock, previous fracture in the upper extremity and autoimmune-mediated inflammatory arthritis. There will be included a total of 122 patients of which 56 will participate in the radiostereometric analysis. This number of patients allows 20% to drop out. The co-primary outcomes are the pattern and magnitude of the migration of the glenoid component assessed by radiostereometric analysis and the Western Ontario Osteoarthritis of the Shoulder index. The secondary outcomes are inferior scapular notching, patient-reported and functional outcomes (Oxford shoulder score, Constant-Murley score and pain), side effects and complications, changes in bone mineral density and economy. The included patients will be examined before the surgery, within 1 week and 3, 6, 12 and 24 months after.
Discussion
No previous studies have compared the conventional reverse shoulder arthroplasty with the lateralized reverse shoulder arthroplasty in a randomized controlled trial regarding migration and functional outcome. Furthermore, radiostereometric analysis has not been used to evaluate the migration of reverse shoulder arthroplasty in a randomized controlled trial. This study intends to determine which treatment has the most optimal outcome for the benefit of future patients with an indication for reverse shoulder arthroplasty.
Trial registration
The study has been notified to Pactius and has approval number P-2021-231. Furthermore, the study will be registered on
Clinicaltrials.gov
before starting the inclusion.
Assessment of maximum aerobic scope, as a proxy for scope of activity, in ectotherms can be instrumental in predicting distributional responses to e.g. global warming. The waters of the Arctic ...regions represent one of the most vulnerable ecosystems to climate change. In this study, we determine the optimum temperature (
T
opt
) of nine adult Arctic charr (
Salvelinus alpinus
) from Qeqertarsuaq, Greenland, using maximum heart rate (
f
Hmax
) for investigating the optimal temperatures for activity. The Arrhenius breakpoint of maximum heart rate measurements occurred between 5.9 and 8.3 °C (average = 7.5 °C ± 0.4). The
Q
10
breakpoint occurred at an average of 7.1 °C ± 0.3. There was no significant difference between the breakpoint temperature found using
Q
10
and Arrhenius two-sample
t
test,
df
= 16;
p
> 0.1. The highest
f
Hmax
was found at 12.8 °C ± 1.0 reaching an average of 61.8 BPM ± 3.1. Arrhythmia occurred between 11 and 18 °C (average = 15.2 °C ± 0.9). The results obtained in this study suggest that the studied population of Arctic charr lives at summer temperatures (−0.6 to 9.1 °C) that are optimal for activity, but an increase in temperature expected with climate change, could have an impact on life cycle events and fitness-related tasks for this northern population.
Abstract Background and purpose The purpose of this retrospective study was to examine the association between shortening of the clavicle after a united midshaft fracture and clinical outcome. ...Second, the purpose was to compare the results obtained by conservative treatment with either a figure-of-eight bandage or a simple sling. Materials and methods This study included 136 patients with a united, conservatively treated, midshaft clavicle fracture. Mean age was 35 years (range 15–70 years); mean follow-up time was 55 months (range 24–83 months). The shortening of the clavicle was measured on a radiograph including one antero-posterior view of both clavicles on a single film and defined as the difference between the injured and the contralateral clavicle. The clinical outcome was measured using the Constant–Murley Score. Results The mean difference in the Constant–Murley Score between the injured and the contralateral shoulder was 7.3, P < 0.001 (95% confidence interval (CI) 5.6; 9.1). Mean shortening of the injured shoulder was 11.6 mm, P < 0.001 (95% CI 10.2; 13.0). A shortening of more than 20 mm was not associated with a poorer clinical outcome. The results obtained by conservative treatment with either a figure-of-eight bandage or a simple sling showed no difference in shortening or in the Constant–Murley Score. Conclusions We found that conservative treatment of midshaft clavicle fractures resulted in final shortening and mild reduction of shoulder function. A shortening of 20 mm or more was not associated with a poorer clinical outcome. The figure-of-eight bandage and a simple sling were equal treatments of midshaft clavicle fractures.
In a clinical setting, a visual evaluation of post-implant radiographs is often used to assess the restoration of glenohumeral joint anatomy after resurfacing hemiarthroplasty and is a part of the ...decision-making process, in combination with other parameters, when evaluating patients with inferior clinical results. However, the reliability of this method of visual evaluation has not been reported. The aim of this study was to investigate the inter- and intra-observer agreement among experienced shoulder surgeons assessing overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs.
Six experienced shoulder surgeons independently classified implant inclination, size of the implant and if the joint seemed overstuffed, in 219 cases of post-implant radiographs. All cases were classified twice 3 weeks apart. Only radiographs with an anterior-posterior projection with a freely visible joint space were used. Non-weighted Cohen's kappa values were calculated for each coder pair and the mean used as an estimate of the overall inter-observer agreement.
The overall inter-observer agreement for implant size (kappa, 0.48 and 0.41) and inclination angle was moderate in both rounds (kappa, 0.46 and 0.44), but only a fair agreement was found concerning the evaluation for stuffing of the joint (kappa, 0.24 and 0.28). Intra-observer agreement for implant size and stuffing ranged from fair to substantial while the agreement for inclination was moderate to substantial.
Our results indicate that a visual evaluation of plain radiographs may be inadequate to evaluate overstuffing, implant positioning, and size following resurfacing hemiarthroplasty using plain standardized radiographs. Future studies may contribute to elucidate whether reliability increases if consensus on clear definitions and standardized methods of evaluation is made.
The indications for surgical intervention in complex fractures of the proximal humerus are disputed. In elderly patients with poor bone stock it may be impossible to obtain satisfactory fixation of ...the tuberosities to a hemiarthroplasty (HA). In such cases primary insertion of a reverse shoulder arthroplasty (RSA) has been suggested. We aimed to review clinical studies reporting benefits and harms of RSA in acute fractures. A systematic review. We included 18 studies containing 430 RSA in acute fractures. We found no randomized clinical trials. Four studies compared outcome after RSA with a historical control group of HA. The median constant score was 58 (range 44-68) which is comparable to previous reviews of HA in 4-part fractures. Complications included dislocation, infection, hematoma, instability, neurological injury, reflex sympathetic dystrophy, intraoperative fractures, periprosthetic fractures, and baseplate failure. Scapular notching was reported in 11 studies with a median value of 25% (range 0-94). Heterogeneity of study designs and lack of primary data precluded statistical pooling of data. No high quality evidence was identified. Based on the available evidence the use of RSA in acute fractures is questionable. The complication rate was high and the clinical implications of long term scapular notching are worrying. Randomized studies with long term follow up using the latest techniques of tubercular reinsertion in RSA toward HA should be encouraged.
The novel anti-ischemic compound, BMS-204352 ((3
S)-(+)-(5-chloro-2-methoxyphenyl)-1,3-dihydro-3-fluoro-6-(trifluoromethyl)-2
H-indol-2-one)), strongly activates the voltage-gated K
+ channel KCNQ5 ...in a concentration-dependent manner with an EC
50 of 2.4 μM. At 10 μM, BMS-204352 increased the steady state current at −30 mV by 12-fold, in contrast to the 2-fold increase observed for the other KCNQ channels Schrøder et al., 2001. Retigabine ((
d-23129;
N-(2-amino-4-(4-fluorobenzylamino)-phenyl) carbamic acid ethyl ester) induced a smaller, yet qualitatively similar effect on KCNQ5. Furthermore, BMS-204352 (10 μM) did not significantly shift the KCNQ5 activation curves (threshold and potential for half-activation,
V
1/2), as observed for the other KCNQ channels. In the presence of BMS-204352, the activation and deactivation kinetics of the KCNQ5 currents were slowed as the slow activation time constant increased up to 10-fold. The M-current blockers, linopirdine (DuP 996; 3,3-bis(4-pyridinylmethyl)-1-phenylindolin-2-one) and XE991 (10,10-bis(4-pyridinylmethyl)-9(10
H)-anthracenone), inhibited the activation of the KCNQ5 channel induced by the BMS-204352. Thus, BMS-204352 appears to be an efficacious KCNQ channels activator, and the pharmacological properties of the compound on the KCNQ5 channel seems to be different from what has been obtained on the other KCNQ channels.
The isolation of the peptide inhibitor of M-type K+ current, BeKm-1, from the venom of the Central Asian scorpion Buthus eupeus has been described previously (Fillipov A. K., Kozlov, S. A., ...Pluzhnikov, K. A., Grishin, E. V., and Brown, D. A. (1996) FEBS Lett. 384, 277–280). Here we report the cloning, expression, and selectivity of BeKm-1. A full-length cDNA of 365 nucleotides encoding the precursor of BeKm-1 was isolated using the rapid amplification of cDNA ends polymerase chain reaction technique from mRNA obtained from scorpion telsons. Sequence analysis of the cDNA revealed that the precursor contains a signal peptide of 21 amino acid residues. The mature toxin consists of 36 amino acid residues. BeKm-1 belongs to the family of scorpion venom potassium channel blockers and represents a new subgroup of these toxins. The recombinant BeKm-1 was produced as a Protein A fusion product in the periplasm of Escherichia coli. After cleavage and high performance liquid chromatography purification, recombinant BeKm-1 displayed the same properties as the native toxin. Three BeKm-1 mutants (R27K, F32K, and R27K/F32K) were generated, purified, and characterized. Recombinant wild-type BeKm-1 and the three mutants partly inhibited the native M-like current in NG108-15 at 100 nm. The effect of the recombinant BeKm-1 on different K+ channels was also studied. BeKm-1 inhibited hERG1 channels with an IC50 of 3.3 nm, but had no effect at 100 nm on hEAG, hSK1, rSK2, hIK, hBK, KCNQ1/KCNE1, KCNQ2/KCNQ3, KCNQ4 channels, and minimal effect on rELK1. Thus, BeKm-1 was shown to be a novel specific blocker of hERG1 potassium channels.
AF276623
Molecular tools are needed for assessing anti-depressant actions by positron emission tomography (PET) in the living human brain.
This study determined whether (11)Cmirtazapine is an appropriate ...molecular tool for use with PET to estimate the magnitude of neuroreceptor occupancy produced by daily intake of mirtazapine.
This study used a randomised, double-blind, placebo-controlled, parallel-group, within-subject design. Eighteen healthy volunteers were PET-scanned twice with (11)Cmirtazapine; once under baseline condition and again after receiving either placebo or mirtazapine (7.5 or 15 mg) for 5 days. We determined kinetic parameters of (11)Cmirtazapine in brain regions by the simplified reference region method and used binding potential values to calculate receptor occupancy produced by mirtazapine.
Serum concentrations of mirtazapine ranged from 33 to 56 nmol/l after five daily doses of 7.5 mg mirtazapine and were between 41 and 74 nmol/l after 15 mg mirtazapine. Placebo treatment failed to alter the binding potential of (11)Cmirtazapine from baseline values, whereas daily intake of mirtazapine markedly decreased the binding potential in cortex, amygdala and hippocampus. Receptor occupancy ranged from 74 to 96% in high-binding regions of the brain after five daily doses of 7.5 mg or 15 mg mirtazapine, whereas 17-48% occupancy occurred in low-binding regions.
(11)CMirtazapine together with PET can determine the degree of receptor occupancy produced by daily doses of mirtazapine in regions of the living human brain.
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