Preservation of both anterior and posterior cruciate ligaments in total knee arthroplasty (TKA) can lead to near-normal post-operative joint mechanics and improved knee function. We hypothesised that ...a patient-specific bicruciate-retaining prosthesis preserves near-normal kinematics better than standard off-the-shelf posterior cruciate-retaining and bicruciate-retaining prostheses in TKA.
We developed the validated models to evaluate the post-operative kinematics in patient-specific bicruciate-retaining, standard off-the-shelf bicruciate-retaining and posterior cruciate-retaining TKA under gait and deep knee bend loading conditions using numerical simulation.
Tibial posterior translation and internal rotation in patient-specific bicruciate-retaining prostheses preserved near-normal kinematics better than other standard off-the-shelf prostheses under gait loading conditions. Differences from normal kinematics were minimised for femoral rollback and internal-external rotation in patient-specific bicruciate-retaining, followed by standard off-the-shelf bicruciate-retaining and posterior cruciate-retaining TKA under deep knee bend loading conditions. Moreover, the standard off-the-shelf posterior cruciate-retaining TKA in this study showed the most abnormal performance in kinematics under gait and deep knee bend loading conditions, whereas patient-specific bicruciate-retaining TKA led to near-normal kinematics.
This study showed that restoration of the normal geometry of the knee joint in patient-specific bicruciate-retaining TKA and preservation of the anterior cruciate ligament can lead to improvement in kinematics compared with the standard off-the-shelf posterior cruciate-retaining and bicruciate-retaining TKA.
: Y-G. Koh, J. Son, S-K. Kwon, H-J. Kim, O-R. Kwon, K-T. Kang. Preservation of kinematics with posterior cruciate-, bicruciate- and patient-specific bicruciate-retaining prostheses in total knee arthroplasty by using computational simulation with normal knee model.
2017;6:557-565. DOI: 10.1302/2046-3758.69.BJR-2016-0250.R1.
We present a measurement of R_{K^{*}}, the branching fraction ratio B(B→K^{*}μ^{+}μ^{-})/B(B→K^{*}e^{+}e^{-}), for both charged and neutral B mesons. The ratio for the charged case R_{K^{*+}} is the ...first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q^{2}. The analysis is based on a data sample of 711 fb^{-1}, containing 772×10^{6} BBover ¯ events, recorded at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The obtained results are consistent with standard model expectations.
Using the entire Belle data sample of 980 fb−1 of e+e− collisions, we present the results of a study of excited Ωc charmed baryons in the decay mode Ξc+K−. We show confirmation of four of the five ...narrow states reported by the LHCb Collaboration: the Ωc(3000), Ωc(3050), Ωc(3066), and Ωc(3090).
Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect ...of PCO and PTS on cruciate retaining TKA.
We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.
Contact stress on the patellar button increased and decreased as PCO translated to the anterior and posterior directions, respectively. In addition, contact stress on the patellar button decreased as PTS increased. These trends were consistent in the FE models with altered PCO. Higher quadriceps muscle and patellar tendon force are required as PCO translated in the anterior direction with an equivalent flexion angle. However, as PTS increased, quadriceps muscle and patellar tendon force reduced in each PCO condition. The forces exerted on the PCL increased as PCO translated to the posterior direction and decreased as PTS increased.
The change in PCO alternatively provided positive and negative biomechanical effects, but it led to a reduction in a negative biomechanical effect as PTS increased.
: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, J-S. Lee, S. K. Kwon. A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty.
2018;7:69-78. DOI: 10.1302/2046-3758.71.BJR-2017-0143.R1.
Objectives To investigate antimicrobial resistance in clinical isolates of Acinetobacter spp. from two Korean hospitals. Methods Two hundred and sixty-five isolates of Acinetobacter spp. from two ...Korean hospitals were collected and were identified to species level using partial rpoB gene sequences. Antimicrobial susceptibility testing was performed using a broth microdilution method. Results rpoB gene sequences indicated that 214 isolates (80.8%) were Acinetobacter baumannii, and allowed these to be classified into three subgroups (I, II and III); 142 isolates (53.6%) belonged to subgroup I, 54 (20.4%) to subgroup II and 18 (6.8%) to subgroup III. Forty-eight isolates (18.1%) and 74 isolates (27.9%) were resistant to polymyxin B and colistin, respectively. However, antimicrobial resistance rates varied markedly between subgroups. While A. baumannii subgroup I showed low resistance rates to polymyxin B and colistin (2.1% and 7.0%, respectively), subgroups II and III showed high resistance rates to these antibiotics (38.9% and 64.8% in subgroup II and 72.2% and 88.9%, in subgroup III, respectively). Multidrug resistance was also significantly more frequent in subgroup I (45.1%) than in subgroups II and III (13.0% and 16.7%, respectively). Conclusions Our data indicate that subgroup identification of A. baumannii may aid selection of appropriate antimicrobial agents for the treatment of Acinetobacter infections.
We report the first observation of the double strange baryon Ξ(1620)0 in its decay to Ξ−π+ via Ξ+c → Ξ−π+π+ decays based on a 980 fb−1 data sample collected with the Belle detector at the KEKB ...asymmetric-energy e+e− collider. The mass and width are measured to be 1610.4 ± 6.0(stat)+6.1−4.2(syst) MeV /c2 and 59.9 ± 4.8(stat)+2.8−7.1(syst) MeV, respectively. We obtain 4.0σ evidence of the Ξ(1690)0 with the same data sample. These results shed light on the structure of hyperon resonances with strangeness S = −2
We report here measurement of the cross section of e+e- → π+π-ψ ( 2S ) between 4.0 and 5.5 GeV, based on an analysis of initial state radiation events in a 980fb-1 data sample recorded with the Belle ...detector. The properties of the Y ( 4360 ) and Y ( 4660 ) states are determined. Fitting the mass spectrum of π+π-ψ ( 2S ) with two coherent Breit-Wigner functions, we discover two solutions with identical mass and width but different couplings to electron-positron pairs: MY ( 4360 ) = ( 4347±6±3 ) MeV / c2 , Γ Y ( 4360 ) = ( 103±9±5 ) MeV , MY ( 4660 ) = ( 4652±10±8 ) MeV / c2 , Γ Y ( 4660 ) = ( 68±11±1 ) MeV ; and B Y ( 4360 ) → π+π-ψ ( 2S ) · Γ Y ( 4360 ) e+e-= ( 10.9±0.6±0.7 ) eV and B Y ( 4660 ) → π+π-ψ ( 2S ) · Γ Y ( 4660 ) e+e-= ( 8.1±1.1±0.5 ) eV for one solution; or B Y ( 4360 ) → π+π-ψ ( 2S ) · Γ Y ( 4360 ) e+e-= ( 9.2±0.6±0.6 ) eV and B Y ( 4660 ) → π+π=ψ ( 2S ) · Γ Y ( 4660 ) e+e-= ( 2.0±0.3±0.2 ) eV for the other. Here, the first errors are statistical and the second systematic. Evidence for a charged charmoniumlike structure at 4.05GeV / c2 is observed in the π±ψ ( 2S ) intermediate state in the Y ( 4360 ) decays. decays.
We measure the inclusive production cross sections of hyperons and charmed baryons from e+e− annihilation using a 800 fb−1 data sample taken near the ϒ(4S) resonance with the Belle detector at the ...KEKB asymmetric-energy e+e− collider. The feed-down contributions from heavy particles are subtracted using our data, and the direct production cross sections are presented for the first time. The production cross sections divided by the number of spin states for S=−1 hyperons follow an exponential function with a single slope parameter except for the Σ(1385)+ resonance. Suppression for Σ(1385)+ and Ξ(1530)0 hyperons is observed. Among the production cross sections of charmed baryons, a factor of 3 difference for Λc+ states over Σc states is observed. This observation suggests a diquark structure for these baryons.
We determined the fecal carriage rate of serotype K1
Klebsiella pneumoniae
in healthy Koreans and studied their genetic relationship with liver abscess isolates. We compared the carriage according to ...the country of residence. The stool specimens were collected through health promotion programs in Korea.
K. pneumoniae
strains were selected and tested for K1 by PCR. Serotype K1 isolates were characterized by multilocus sequence typing and pulsed field gel electrophoresis. A total of 248
K. pneumoniae
isolates were obtained from 1,174 Koreans. Serotype K1 was identified in 57 (4.9%), of which 54 (94.7%) were ST 23 and were closely related to the liver abscess isolates. Participants aged >25 years showed a higher fecal carriage rate than those ≤ 25 (
P
= 0.007). The proportion of serotype K1 out of
K. pneumoniae
isolates in foreigners of Korean ethnicity who had lived in other countries was lower compared with those who had lived in Korea (5.6% vs 24.1%,
P
= 0.024). A substantial proportion of Koreans >25 years carries serotype K1
K. pneumoniae
ST23 strains, which are closely related to liver abscess isolates. Differences in carriage rates by country of residence suggests that environmental factors might play an important role in the carriage of this strain.
Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, ...and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009–2013). One hundred and twenty‐six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kUA/l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.
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