306 results on '"B. Schoch"'
Search Results
152. ReactionBe9(γ, π+)Li9(g.s.)atθπ=90°
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P. K. Teng, N. Paras, M. Pauli, P.F. Yergin, E. J. Winhold, A. Chaudhury, Aron M. Bernstein, J. LeRose, D. Rowley, K. Min, P. Stoler, K. I. Blomqvist, B. O. Sapp, G. B. Franklin, and B. Schoch
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Physics ,Nuclear reaction ,Nuclear and High Energy Physics ,Light nucleus ,Angular distribution ,Meson ,Isotopes of lithium ,Hadron ,Pi ,Analytical chemistry ,Atomic physics - Abstract
Differential cross sections at theta/sub ..pi../ = 90/sup 0/ (lab) for /sup 9/Be(..gamma..,..pi../sup +/)/sup 9/Li(g.s.) at T/sub ..pi../ = 17, 29, and 42 MeV were measured. Results are compared to other data and to Helm model calculations.
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- 1982
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153. A method for measuring total cross sections of (γ, π−) reactions at threshold
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Peter Jennewein, Horst Göringer, B. Schoch, Gerold Lührs, Franz Zettl, and Friedrich R. Klein
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Nuclear physics ,Physics ,Time of flight ,Near threshold ,Low energy ,Pion ,Spectrometer ,Nuclear Theory ,Photon beams ,Neutron ,General Medicine ,Atomic physics ,Nuclear Experiment - Abstract
A new method for detecting low energy negative pions has been investigated. The negative pions are identified via monoenergetic neutrons produced in the reaction π − + D → 2 n and detected by means of a time of flight spectrometer. The feasibility for measuring D ( γ , π − ) cross sections near threshold is demonstrated; an extension to heavier nuclei seems to be possible. Futher the method is well suited for applications together with tagged photon beams.
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- 1981
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154. Cross-sections for the (γ, n) reaction in9Be,12C and16O at 60 MeV photon energy
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H. Schier and B. Schoch
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Physics ,Nuclear physics ,Excited state ,Binding energy ,General Physics and Astronomy ,Neutron ,Photon energy ,Atomic physics - Published
- 1975
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155. Cross sections for the reactionO16(γ, p0)N15at forward angles forEγ=80MeV
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F. Klein, P. Jennewein, F. Zettl, G. Lührs, H. Göringer, and B. Schoch
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Physics ,Nuclear and High Energy Physics ,Atomic physics - Published
- 1980
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156. Pion Spectra to Individual Final States in the Reactions 12C(γ,π±)12B, 12N
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D. Rowley, J. Lerose, K. Min, K. I. Blomqvist, G. Franklin, N. Paras, E. J. Winhold, P. F. Yergin, Aron M. Bernstein, B. Schoch, P. Stoler, and M. Pauli
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Physics ,Particle physics ,Operator (physics) ,Nuclear Theory ,Electron ,Spectral line ,Nuclear physics ,Pion ,medicine.anatomical_structure ,Excited state ,medicine ,Photon beam ,Nuclear Experiment ,Nucleus - Abstract
The cross sections for the reactions 12C(γ,π+)12B and 12C(γ,π−)12N to various states of the final nucleus have been measured at a pion energy around 29 MeV for electron energies from 187 to 193 MeV, and at a pion energy around 17 MeV with electron energies from 174 to 181 MeV, and at a pion angle 90° with respect to the incident photon beam. The observed states in 12B and 12N are the analogues of T = 1 states in 12C which are excited by inelastic electron scattering1,2. Furthermore, the (γ,π) one-body operator tends to strongly excite spin-flip components of the transitions to these states.
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- 1979
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157. ChemInform Abstract: PHASE EQUILIBRIA AND ION CONDUCTION OF THE LITHIUM FLUORIDE-LITHIUM HYDRIDE AND LITHIUM FLUORIDE-LITHIUM HYDROXIDE SYSTEMS
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Albrecht Rabenau, H. Hahn, Werner Weppner, and B. Schoch
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chemistry.chemical_compound ,chemistry ,Lithium vanadium phosphate battery ,Lithium hydride ,Phase (matter) ,Inorganic chemistry ,Lithium fluoride ,General Medicine ,Thermal conduction ,Lithium hydroxide ,Nuclear chemistry ,Ion - Published
- 1985
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158. Detection of hard photons with BaF$_2$ scintillators
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U. Kneissl, Gilbert Koch, B. Haas, R. Riess, W. Wilke, R. Hingmann, R. W. Novotny, R. Beck, H. Ströher, R. Mühlhans, V. Metag, R.D. Fischer, Yves Roland Schutz, J.P. Vivien, B. Schoch, W. Kühn, Institut de Recherches Subatomiques (IReS), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS)
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Nuclear physics ,Physics ,Nuclear and High Energy Physics ,Photon ,Monte Carlo method ,Physics::Optics ,Scintillator ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Instrumentation ,Photon detection ,Computational physics ,Line (formation) - Abstract
Large BaF 2 crystals have been used for hard photon detection. The response to γ-rays with energies up to 130 MeV has been measured by means of tagged photons. Experimental line shapes and resolutions are compared to simulations with the Monte Carlo shower code GEANT3.
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- 1987
159. A Method for Measurements of the Total 2H(γ,π−)PP Cross Sections at Threshold
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F. Klein, B. Schoch, and G. Lührs
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Nuclear physics ,Physics ,Cross section (physics) ,Time of flight ,Quality (physics) ,Deuterium ,Neutron detection ,Neutron ,Monochromatic color ,Photon beam - Abstract
In recent years measurements of the total cross section for the reactions 2H(γ,π+ nn) and 2H(γ,π0)2H close to the production threshold were performed1. For the 2H(γ,π−)pp reaction data of similar good quality doesn’t exist. In this paper a method is prescribed and the feasibility for the reaction 2H(γ,π−)pp is demonstrated. Figure 1 shows the principle: The photon beam hits a liquid or high pressured gas target of 2H. π− are created on the deuteron and stopped in the same target cell. The major part of the tt are captured π− are captured by deuterons via the reaction 2H(π−,n)n. The energy is shared equally by the two neutrons (En= 68.2 MeV). One of these monochromatic neutrons is detected by a neutron detector using the time of flight method.
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- 1979
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160. Inclusive Electroproduction of Low Energy Pi Mesons
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E. J. Winhold, G. Franklin, K. Min, N. Paras, J. Lerose, K. I. Blomqvist, A. M. Berstein, P. F. Yergin, D. Rowley, B. Schoch, P. Stoler, and M. Pauli
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Physics ,Particle physics ,Meson ,Nuclear Theory ,Virtual particle ,medicine.anatomical_structure ,Electromagnetic interaction ,Pion ,Low energy ,medicine ,Nuclear Experiment ,Nucleus ,Beam energy ,Computer Science::Databases - Abstract
Because the electromagnetic interaction is well known and because the real or virtual photon can create a pion at any point inside the target nucleus, the study of gamma-pi type experiments can give important information concerning the final state interaction of the pion with the daughter nucleus.
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- 1979
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161. Temporary Neutron Damage in Transistors
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B. Barnett, C. B. Schoch, L. M. Langsam, and D. A. Schow
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Materials science ,Order of reaction ,Annealing (metallurgy) ,First-order reaction ,Neutron ,Activation energy ,Trapping ,Electron ,Radiation ,Atomic physics - Abstract
The amount and duration of temporary neutron damage were measured in a wide variety of types of transistors at the White Sands Pulsed Reactor. They all shoed a decrease in the large-signal common-emitter current gain lasting about one second. Half of the damage recovered in a time of 0.0002 to 0.05 sec, for different types, and the ratio of the peak damage (just after the burst) to the permanent damage varied from 1.5 to 3. The amount and duration of the effect were much smaller in samples operated at relatively high junction temperatures. A model is proposed to explain the effect on the basis of the kinetics of the trapping and recombination processes occuring, in a pnp transistor, for example, lattice + radiation ko ? ? K5 T T + n k1 ? ? K2 T- T- + p k3 ? ?K4 T where T- and T signify loaded and unloaded traps, and n and p electrons and holes, respectively. The recovery of the gain is not first order, so that the k3 reaction alone does not dominate the recovery. The k5 annealing reaction is observed well above room temperature. The main reactions involved in the recovery are the k2, k3 and k4 reactions. On the assumption of a first order reaction, the activation energy was found to be ~ 0.11 ev. Deviations from first order were attributed to a net second order reaction with a very small activation energy. The value ~ 0.
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- 1966
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162. The Effects of High Energy Radiation on Failure Mechanisms in Semiconductors Devices
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C. B. Schoch and V. R. Honnold
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Semiconductor ,Materials science ,business.industry ,Ionization ,Semiconductor materials ,Gamma ray ,Optoelectronics ,Semiconductor device ,business ,Radiofrequency radiation ,Ionizing radiation - Published
- 1962
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163. ROBERT B. J. SCHOCH, M.D
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R B, SCHOCH
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History ,Humans - Published
- 1963
164. Ionic transport phenomena in nanofluidics: Experimental and theoretical study of the exclusion-enrichment effect on a chip
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Adrien Plecis, Philippe Renaud, and Reto B. Schoch
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fixed charges ,Nanostructure ,interconnects ,Ionic bonding ,nanofiltration membranes ,Bioengineering ,Nanofluidics ,Nanotechnology ,channels ,Ion ,Ionic conductivity ,General Materials Science ,microfluidic devices ,glass ,chemistry.chemical_classification ,model ,behavior ,Mechanical Engineering ,selectivity ,General Chemistry ,Condensed Matter Physics ,Electrostatics ,chemistry ,Chemical physics ,electrolyte-solutions ,Counterion ,Transport phenomena - Abstract
In nanometer-sized apertures with charged surfaces, the extension of the electrical double layer results in the electrostatic exclusion of co-ions and enrichment in counterions, which affects the permselectivity of such structures. A modeling of this phenomenon is proposed and is compared with quantitative measurements of the ionic permeability change of a Pyrex nanoslit at low ionic strength. The comparison of experimental results with theoretical predictions justifies that electrostatic forces are the governing forces in nanofluidics.
165. Microelectrical impedance tomography for biophysical characterization of thin film biomaterials
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P. Linderholm, Ph. Renaud, and Reto B. Schoch
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Microelectrode ,Materials science ,business.industry ,Electrical resistivity and conductivity ,Self-healing hydrogels ,Electrode ,Analytical chemistry ,Optoelectronics ,Thin film ,Methacrylate ,business ,Layer (electronics) ,Electrical impedance - Abstract
We present a new method for measuring the electrical resistivities of a stratified sample of thin biomaterials or tissue layers. The presented technique makes use of impedance measurements between 11 pairs of electrodes separated by varying distances. The electrodes are made of gold stripes, 20-500 /spl mu/m wide and 8 mm long. We used hydrogels of poly-hydroxyethyl methacrylate (pHEMA) as a model material for our measurements. By changing the concentration of cross-linker we were able to tune the resistivity of the hydrogel between 1,000 /spl Omega/m and 17,000 /spl Omega/m. Using these hydrogels we were able to detect a change in resistivity of a 120 /spl mu/m layer lying 250 /spl mu/m into the sample.
166. Transport phenomena in nanofluidics
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Jongyoon Han, Philippe Renaud, and Reto B. Schoch
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Physics ,Isoelectric point ,Chemical physics ,Ionic strength ,General Physics and Astronomy ,Ionic bonding ,Nanotechnology ,Fluorescence correlation spectroscopy ,Nanofluidics ,Electrolyte ,Ion ,Concentration polarization - Abstract
This thesis explores transport phenomena in nanochannels on a chip. Fundamental nanofluidic ionic studies form the basis for novel separation and preconcentration applications for proteomic purposes. The measurements were performed with 50-nm-high 1D nanochannels, which are easily accessible from both sides by two microchannels. Nanometer characteristic apertures were manufactured in the bonded structure of Pyrex-amorphous silicon – Pyrex, in which the thickness of the amorphous silicon layer serves as a spacer to define the height of the nanochannels. The geometry of the nanometer-sized apertures is well defined, which simplifies the modeling of the transport across them. Compared to biological pores, the present nanochannels in Pyrex offer increased stability. Fundamental characteristics of nanometer-sized apertures were obtained by impedance spectroscopy measurements of the nanochannel at different ionic strengths and pH values. A conductance plateau (on a log-log scale) was modeled and measured, establishing due to the dominance of the surface charge density in the nanochannels, which induces an excess of mobile counterions to maintain electroneutrality. The nanochannel conductance can be regulated at low ionic strengths by pH adjustment, and by an external voltage applied on the chip to change the zeta potential. This field-effect allows the regulation of ionic flow which can be exploited for the fabrication of nanofluidic devices. Fluorescence measurements confirm that 50-nm-high nanochannels show an exclusion of co-ions and an enrichment of counterions at low ionic strengths. This permselectivity is related to the increasing thickness of the electrical double layer (EDL) with decreasing salt concentrations, which results in an EDL overlap in an aperture if the height of the nanochannel and the thickness of the EDL are comparable in size. The diffusive transport of charged species and therefore the exclusion-enrichment effect was described with a simple model based on the Poisson-Boltzmann equation. The negatively charged Pyrex surface of the nanometer characteristic apertures can be inversed with chemical surface pretreatments, resulting in an exclusion of cations and an enrichment of anions. When a pressure gradient is applied across the nanochannels, charged molecules are electrostatically rejected at the entrance of the nanometer-sized apertures, which can be used for separation processes. Proteomic applications are presented such as the separation and preconcentration of proteins. The diffusion of Lectin proteins with different isoelectric points and very similar compositions were controlled by regulating the pH value of the buffer. When the proteins are neutral at their pI value, the diffusion coefficient is maximal because the biomolecules does not interact electrostatically with the charged surfaces of the nanochannel. This led to a fast separation of three Lectin proteins across the nanochannel. The pI values measured in this experiment are slightly shifted compared to the values obtained with isoelectric focusing because of reversible adsorption of proteins on the walls which affects the pH value in the nanochannel. An important application in the proteomic field is the preconcentration of biomolecules. By applying an electric field across the nanochannel, anionic and cationic analytes were preconcentrated on the cathodic side of the nanometer-sized aperture whereas on the anodic side depletion of ions was observed. This is due to concentration polarization, a complex of effects related to the formation of ionic concentration gradients in the electrolyte solution adjacent to an ion-selective interface. It was measured that the preconcentration factor increased with the net charge of the molecule, leading to a preconcentration factor of > 600 for rGFP proteins in 9 minutes. Such preconcentrations are important in micro total analysis systems to achieve increased detection signals of analytes contained in dilute solutions. Compared to cylindrical pores, our fabrication process allows the realization of nanochannels on a chip in which the exclusion-enrichment effect and a big flux across the nanometer-sized aperture can be achieved, showing the interest for possible micro total analysis system applications. The described exclusion-enrichment effect as well as concentration polarization play an important role in transport phenomena in nanofluidics. The appendix includes preliminary investigations in DNA molecule separation and fluorescence correlation spectroscopy measurements, which allows investigating the behavior of molecules in the nanochannel itself.
167. The influence of focal cerebellar lesions on the control and adaptation of gait.
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W. Ilg, M. A. Giese, E. R. Gizewski, B. Schoch, and D. Timmann
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CEREBELLAR ataxia ,CEREBELLAR nuclei ,GAIT disorders ,BRAIN tumors ,THREE-dimensional imaging ,CEREBELLUM - Abstract
Cerebellar ataxic gait is influenced greatly by balance disorders, most likely caused by lesions of the medial zone of the cerebellum. The contributions of the intermediate and lateral zone to the control of limb dynamics for gait and the adaptation of locomotor patterns are less well understood. In this study, we analysed locomotion and goal-directed leg movements in 12 patients with chronic focal lesions after resection of benign cerebellar tumours. The extent of the cortical lesion and possible involvement of the cerebellar nuclei was determined by 3D-MR imaging. The subjects (age range 13–39 years, mean 20.3; seven female; ICARS score: mean 5.7, SD 6.3) performed three tasks: goal-directed leg placement, walking and walking with additional weights on the shanks. Based on the performance on the first two tasks, patients were categorized as impaired or unimpaired for leg placement and for dynamic balance control in gait. The subgroup with impaired leg placement but not the subgroup with impaired balance showed abnormalities in the adaptation of locomotion to additional loads. A detailed analysis revealed specific abnormalities in the temporal aspects of intra-limb coordination for leg placement and adaptive locomotion. These findings indicate that common neural substrates could be responsible for intra-limb coordination in both tasks. Lesion-based MRI subtraction analysis revealed that the interposed and the adjacent dentate nuclei were more frequently affected in patients with impaired compared to unimpaired leg placement, whereas the fastigial nuclei (and to a lesser degree the interposed nuclei) were more frequently affected in patients with impaired compared with unimpaired dynamic balance control. The intermediate zone appears thus to be of particular importance for multi-joint limb control in both goal-directed leg movements and in locomotion. For locomotion, our results indicate an influence of the intermediate zone on dynamic balance control as well as on the adaptation to changes in limb dynamics. [ABSTRACT FROM AUTHOR]
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- 2008
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168. Initial clinical experience with a predictive clinical decision support tool for anatomic and reverse total shoulder arthroplasty.
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Simmons C, DeGrasse J, Polakovic S, Aibinder W, Throckmorton T, Noerdlinger M, Papandrea R, Trenhaile S, Schoch B, Gobbato B, Routman H, Parsons M, and Roche CP
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- Humans, Treatment Outcome, Patient Satisfaction, Range of Motion, Articular, Retrospective Studies, Arthroplasty, Replacement, Shoulder methods, Shoulder Joint surgery, Decision Support Systems, Clinical
- Abstract
Purpose: Clinical decision support tools (CDSTs) are software that generate patient-specific assessments that can be used to better inform healthcare provider decision making. Machine learning (ML)-based CDSTs have recently been developed for anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty to facilitate more data-driven, evidence-based decision making. Using this shoulder CDST as an example, this external validation study provides an overview of how ML-based algorithms are developed and discusses the limitations of these tools., Methods: An external validation for a novel CDST was conducted on 243 patients (120F/123M) who received a personalized prediction prior to surgery and had short-term clinical follow-up from 3 months to 2 years after primary aTSA (n = 43) or rTSA (n = 200). The outcome score and active range of motion predictions were compared to each patient's actual result at each timepoint, with the accuracy quantified by the mean absolute error (MAE)., Results: The results of this external validation demonstrate the CDST accuracy to be similar (within 10%) or better than the MAEs from the published internal validation. A few predictive models were observed to have substantially lower MAEs than the internal validation, specifically, Constant (31.6% better), active abduction (22.5% better), global shoulder function (20.0% better), active external rotation (19.0% better), and active forward elevation (16.2% better), which is encouraging; however, the sample size was small., Conclusion: A greater understanding of the limitations of ML-based CDSTs will facilitate more responsible use and build trust and confidence, potentially leading to greater adoption. As CDSTs evolve, we anticipate greater shared decision making between the patient and surgeon with the aim of achieving even better outcomes and greater levels of patient satisfaction., (© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)
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- 2024
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169. Scapulothoracic Fusion Using Multiple Suture Tape Cerclage.
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Ba PA, Schoch B, and Werthel JD
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- Humans, Range of Motion, Articular, Retrospective Studies, Scapula surgery, Sutures, Shoulder Joint surgery, Muscular Dystrophy, Facioscapulohumeral surgery
- Abstract
Abstract: Scapulothoracic arthrodesis has been proposed for the treatment of painful scapular winging in patients with facioscapulohumeral muscular dystrophy. It was introduced to improve shoulder function. Several methods of fixation have been proposed to obtain the union of the scapula to the ribs. These include plates, screws, cables, or wires with or without bone grafting. The purpose of this manuscript is to describe the surgical technique of scapulothoracic arthrodesis using plate and cerclage suture tapes., Level of Evidence: Level IV, treatment study (case series)., Competing Interests: Conflicts of Interest and Source of Funding: The authors report no conflicts of interest and no source of funding., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)
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- 2023
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170. Impact of age on shoulder range of motion and strength.
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Pike JM, Singh SK, Barfield WR, Schoch B, Friedman RJ, and Eichinger JK
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Background: Total shoulder arthroplasty (TSA) is a surgical technique commonly used to treat patients with arthritis and rotator cuff deficiency. Its purpose is to reduce pain and improve shoulder function, namely range of motion (ROM) and strength. While shoulder ROM and strength have been studied extensively in patients with various shoulder pathologies, there is a dearth of knowledge with regard to the asymptomatic population., Methods: A cross-sectional study was conducted in the outpatient orthopaedic clinic following institutional review board approval. Patients 18 years of age and older with at least one asymptomatic and healthy shoulder with no prior history of shoulder surgery, injury, or pain were enrolled in the study. Demographic information, ROM, and strength measurements were collected for 256 shoulders, evenly stratified into groups by age and sex. A goniometer was used to measure forward elevation, abduction, and external rotation, and a handheld dynamometer was utilized for measuring strength. Statistical evaluation was conducted using Pearson correlations, analysis of variance, and Bonferroni and Mann-Whitney post hoc tests, with P < .01 indicating a significant difference., Results: Abduction strength ( P < .001), external rotation strength ( P < .001), and internal rotation strength ( P < .001) were negatively correlated with age when viewing the data as a whole and after stratification of males and females. Age and shoulder ROM, namely abduction ( P < .001) and forward elevation ( P < .001), were also significantly negatively correlated, although internal rotation decreased with age as well. When comparing across age groups, abduction ( P = .001) and forward elevation ( P = .001) were significantly higher in group 1 (18-35) when compared to group 4 (66+), but external rotation was not significantly different between these groups. External rotation ( P = .001) was only significantly different between groups 2 (36-50) and 4. Variation in external rotation strength was also found. Group 4 was found to have significantly less strength than all 3 of the other groups., Conclusion: Shoulder strength significantly decreased with age, with abduction strength and external rotation strength displaying the strongest negative correlations. Decreases in strength were most prominent in patients 66 years of age and above. Shoulder ROM was not as tightly correlated with age, although abduction, forward elevation, and internal rotation were found to generally decrease over time. Differences in external rotation were not clinically significant. These correlations provide useful controls for patients of various ages regarding their clinical outcomes when presenting with shoulder pathology. Variations in current literature allow this study to verify the impact of age on shoulder ROM and strength., (© 2022 The Authors.)
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- 2022
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171. Severe acromioclavicular joint osteoarthritis is associated with acromial stress fractures after reverse shoulder arthroplasty.
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Townsend CB, Wright J, Wright TW, Pazik M, Schoch B, Gil J, and King JJ
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Background: Little is known about the role of disorders of the acromioclavicular joint (ACJ) and how they relate to complications after reverse shoulder arthroplasty (RSA). The purpose of this study is to compare the severity of ACJ osteoarthritis in patients undergoing RSA with and without postoperative acromial and scapular spine fractures., Methods: A retrospective review was performed to identify all patients who underwent primary RSA between 1/1/2007 and 10/31/2019 with a postoperative acromial or scapular spine stress fracture from a single institution. Patients who underwent RSA with a fracture were compared with an age-, sex-, and preoperative diagnosis-matched control group (1:4 controls) with a minimum 2-year follow-up. We compared demographics, medical comorbidities, and ACJ osteoarthritis between the 2 groups. Preoperative radiographs and 3-dimensional computed tomography scans were evaluated for ACJ osteoarthritis in all patients. The Petersson classification, a modified Petersson classification, location of the osteophytes, subchondral cysts, ACJ space, and size of the largest osteophyte were recorded and compared between the 2 groups., Results: The study included 11 patients who underwent primary RSA (8 women and 3 men) with acromial (6) and scapular spine (5) fractures confirmed radiographically and 44 matched controls (average follow-up 3.1 vs. 4.3 years, P = .17). Average age at surgery was similar between study and control groups (69.6 vs. 70.0 years, P = .86). ACJ osteoarthritis with osteophytes larger than 2 mm was common and similar between the 2 groups (91% of patients with acromial fracture and 66% of controls, P = .15). There was no significant difference in the size or location of the ACJ osteophytes. The Petersson classification was similar between groups. However, the percentage of patients with subchondral ACJ cysts was higher in the fracture group (91% vs. 50%, P = .02), and the percentage of patients with large spanning or fused osteophytes was significantly higher in the fracture group (55% vs. 14%, P = .008)., Conclusion: Radiographic ACJ osteoarthritis is common in patients undergoing RSA. Severe ACJ osteoarthritis with completely spanning or fused osteophytes may predispose patients to acromial or scapular spine fractures after RSA., (© 2021 The Authors.)
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- 2021
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172. Superior capsular reconstruction - A systematic review and meta-analysis.
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Werthel JD, Vigan M, Schoch B, Lädermann A, Nourissat G, and Conso C
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- Arthroscopy methods, Fascia Lata transplantation, Female, Humans, Male, Range of Motion, Articular, Rotator Cuff surgery, Treatment Outcome, Rotator Cuff Injuries surgery, Shoulder Joint diagnostic imaging, Shoulder Joint surgery
- Abstract
Background: Since Mihata's 2012 proposal to arthroscopically reconstruct the superior capsule of patients with massive irreparable cuff tears, many studies have reported the clinical results of this technique using different types of grafts (fascia lata autograft, dermal allograft, porcine dermal xenograft or long head of biceps autograft)., Purpose: The objective of this meta-analysis was to report the clinical and radiological results of these superior capsule reconstructions., Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) recommendations were used to conduct this systematic review. A bibliographic search was performed of the electronic databases MEDLINE, Scopus, Embase and the Cochrane Library. The quality of the studies was assessed according to the MINORS criterion (Methodological Index for Nonrandomized Studies). The inclusion criteria were studies in English evaluating superior capsular reconstruction., Results: No level I or II studies met the inclusion criteria. Eighteen studies were selected from the 97 identified, including 637 shoulders (64% male) with a mean age of 62 years [95% CI: 60.3-63.5]. At the mean follow-up of 24.3 months (12-60), the range of motion was significantly increased from 82.6° [60.0-105.2] to 141.9° [109.9-173.8] in abduction, from 113.1° [98.3-127.9] to 153.3° [147.4-159.2] in elevation, from 35.5° [30.9-40.2] 43.4° [35.4-51.3] in external rotation and from 7.2 [5.4-9] to 9.9 [8.9-10.9] in internal rotation. Functional scores were significantly improved from 5.4 [4.8-5.9] to 1.3 [0.9-1.7] points for VAS, from 42.5 [15.7-69.3] to 59.3 [30.1-88.6] points for Constant, from 39.0% [38.1-39.8] to 79.8% [76.4-83.3] for the SSV, and from 48.2 [45.2-51.1] to 81.2 [77.2-85.1] points for the ASES. The healing rate was 76.1% [64.4-84.9]. The complication rate was 5.6% [1.8-16.3] and the reverse shoulder arthroplasty revision rate was 7.1% [3.8-12.8]., Conclusion: Superior capsule reconstructions allow satisfactory clinical and radiological results to be obtained at 2 years of follow-up. Due to the small number of high quality comparative studies available, its true place in the therapeutic arsenal cannot be fully confirmed. However, it seems that the best indication for this technique is isolated irreparable rupture of the supraspinatus, in cases of medical treatment failure., Level of Evidence: III; meta-analysis of heterogeneous studies., (Copyright © 2021. Published by Elsevier Masson SAS.)
- Published
- 2021
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173. Risk factors for complications and revision surgery after anatomic and reverse total shoulder arthroplasty.
- Author
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Aibinder W, Schoch B, Parsons M, Watling J, Ko JK, Gobbato B, Throckmorton T, Routman H, Fan W, Simmons C, and Roche C
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- Female, Humans, Male, Range of Motion, Articular, Reoperation, Risk Factors, Treatment Outcome, Arthroplasty, Replacement, Shoulder adverse effects, Shoulder Joint surgery
- Abstract
Background: Complications and revisions following anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty have deleterious effects on patient function and satisfaction. The purpose of this study is to evaluate patient-specific, implant-specific and technique-specific risk factors for intraoperative complications, postoperative complications, and the occurrence of revisions after aTSA and rTSA., Methods: A total of 2964 aTSA and 5616 rTSA patients were enrolled in an international database of primary shoulder arthroplasty. Intra- and postoperative complications, as well as revisions, were reported and evaluated. Multivariate analyses were performed to quantify the risk factors associated with complications and revisions., Results: aTSA patients had a significantly higher complication rate (P = .0026) and a significantly higher revision rate (P < .0001) than rTSA patients, but aTSA patients also had a significantly longer average follow-up (P < .0001) than rTSA patients. No difference (P = .2712) in the intraoperative complication rate was observed between aTSA and rTSA patients. Regarding intraoperative complications, female sex (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.17-3.68) and previous shoulder surgery (OR 2.9, 95% CI 1.73-4.90) were identified as significant risk factors. In regard to postoperative complications, younger age (OR 0.987, 95% CI 0.977-0.996), diagnosis of rheumatoid arthritis (OR 1.76, 95% 1.12-2.65), and previous shoulder surgery (OR 1.42, 95% CI 1.16-1.72) were noted to be risks factors. Finally, in regard to revision surgery, younger age (OR 0.964, 95% CI 0.933-0.998), more glenoid retroversion (OR 1.03, 95% CI 1.001-1.058), larger humeral stem size (OR 1.09, 95% CI 1.01-1.19), larger humeral liner thickness or offset (OR 1.50, 95% CI 1.18-1.96), larger glenosphere diameter (OR 1.16, 95% CI 1.07-1.26), and more intraoperative blood loss (OR 1.002, 95% CI 1.001-1.004) were noted to be risk factors., Conclusions: Studying the impact of numerous patient- and implant-specific risk factors and determining their impact on complications and revision shoulder arthroplasty can assist surgeons in counseling patients and guide patient expectations following aTSA or rTSA. Care should be taken in patients with a history of previous shoulder surgery, who are at increased risk of both intra- and postoperative complications., (Copyright © 2021 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
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- 2021
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174. Influence of Thoracic Kyphosis on Reverse Total Shoulder Arthroplasty Outcomes.
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Reintgen C, Armington S, Vigan M, Werthel JD, Patrick M, King J, Wright T, and Schoch B
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- Female, Humans, Range of Motion, Articular, Retrospective Studies, Treatment Outcome, Arthroplasty, Replacement, Shoulder, Kyphosis diagnostic imaging, Kyphosis etiology, Kyphosis surgery, Shoulder Joint surgery
- Abstract
Introduction: Patient dissatisfaction after primary reverse total shoulder arthroplasty (rTSA) has been reported as high as 9%. In patients with excessive thoracic kyphosis, the scapula protracts and tilts anteriorly, which may lead to early impingement with the acromion and loss of forward elevation. The primary purpose of this study was to evaluate the effect of thoracic kyphosis on overhead ROM after rTSA., Methods: A prospectively collected shoulder registry was retrospectively reviewed for all patients undergoing primary rTSA with a minimum of 2-year follow-up. Preoperative and latest follow-up ROM (forward elevation, abduction, internal rotation, and external rotation), patient-reported outcome measures (SPADI, SST-12, ASES, UCLA, SF-12, and the visual analog scale), and the Constant score were collected. Postoperative radiographs were evaluated for implant loosening and notching. Patients were separated into three groups according to the thoracic kyphosis angle (<25°, 25 to 45°, and >45°) and also analyzed as a continuous variable. The groups were compared using analysis of variance and chi-square tests as indicated., Results: Three hundred five shoulders in 279 patients were reviewed at a mean follow-up of 3.9 years (range 2 to 10 years). Female patients and patients with a history of heart disease were statistically more likely to have increased thoracic kyphosis (P < 0.05). After surgery, forward elevation and abduction were similar among all groups (<25: 133°, 25 to 45: 132°, >45: 127°; P = 0.199 and <25: 123°, 25 to 45: 122°, >45: 117°; P = 0.330). All other postoperative ROM measurements and all patient-reported outcome measures were also similar, regardless of measured kyphosis. In addition, no association was observed between the degree of thoracic kyphosis and scapular notching (P = 0.291)., Discussion: Despite thoracic kyphosis being a known risk factor for loss of overhead motion in the native shoulder, shoulders with excessive thoracic kyphosis demonstrated similar overhead ROM at early follow-up after primary rTSA., Level of Evidence: III., (Copyright © 2021 by the American Academy of Orthopaedic Surgeons.)
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- 2021
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175. Long-term results of arthroscopic Bankart repairs for anterior instability of the shoulder in patients aged thirty years or older.
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Delgrande D, Lonjon G, Hardy P, Schoch B, and Werthel JD
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- Adult, Arthroscopy, Humans, Recurrence, Retrospective Studies, Shoulder, Joint Instability surgery, Shoulder Dislocation surgery, Shoulder Joint surgery
- Abstract
Introduction: Bankart repair is a popular treatment for anterior shoulder instability. However, long-term failure rates of arthroscopic Bankart repair remain higher than Latarjet procedures. The purpose of this study was to report long-term results of arthroscopic Bankart repair in patients greater than 30 years old and analyze risk factors of failure following arthroscopic Bankart repair that are independent of younger age., Materials and Methods: Between January 1999 and December 2003, 41 patients aged 30 years or older treated with arthroscopic Bankart repair for anterior shoulder instability were evaluated. Outcome measures included pain (VAS), range of motion, post-operative Walch-Duplay, WOSII scores, complications, failure rate, and risk factors of failure. Failure was defined as recurrent dislocation or subluxation., Results: At a mean 12-year follow-up (range; 10-15 years), the failure rate of arthroscopic Bankart repair in patients aged 30 years and older was 37%. The mean post-operative Walch-Duplay score was significantly higher in patients who had no recurrence compared to those who had had recurrence of instability (100 versus 90, p=0.02). An ISIS score≥3 (p=0.02), a glenoid bone lesion (p=0.06), and a Hill-Sachs lesion>15% defect (p=0.001) were risk factors for recurrent instability. When considering a modified ISIS score that accounted for bony defects on the glenoid and humeral side, patients with an ISIS score <3 + no glenoid lesion + Hill-Sachs ≤ 15% had a recurrence rate of 0%., Conclusion: The failure rate of arthroscopic Bankart repairs in patients over 30 was higher than previously reported. Specifically, patients with an ISIS >3 and bony glenoid defects and/or Hill-Sachs lesions > 15% may be at higher risk for recurrent instability following an isolated arthroscopic Bankart repair. Alternative stabilization techniques may need to be considered for this subset of patients.
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- 2021
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176. Surgical Treatment of Adhesive Capsulitis: A Retrospective Comparative Study of Manipulation Under Anesthesia and/or Capsular Release.
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Schoch B, Huttman D, Syed UA, Patel MS, Lazarus MD, and Abboud JA
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Background No consensus exists among orthopedic surgeons regarding the optimal intervention for adhesive capsulitis. The purpose of this study was to determine which treatment provides the best objective outcome following manipulation under anesthesia (MUA), MUA + arthroscopic capsular release (CR), or CR alone. Methods Between 2011 and 2015, 97 shoulders were treated for adhesive capsulitis (MUA, MUA+CR, CR) and followed for three months or until achieving full range of motion (ROM). Patients' charts were reviewed for demographic information, diabetes, pre/post-operative ROM, and complications. Results The average age at surgery was 57 years (range: 31-80 years) with a mean follow-up of 6.2 months (range: 2-43 months). ROM improved significantly regardless of treatment modality (p < 0.001). MUA had significantly more external rotation at follow-up than MUA+CR and CR alone (62 vs 49 vs 48, p = 0.02). Groups were similar in regards to post-operative elevation and internal rotation. Loss of external rotation following surgery was significantly more common in the MUA+CR group (p = 0.03). In diabetics, no treatment option was superior to another in regards to final ROM. Conclusion Operative treatment of idiopathic adhesive capsulitis is efficacious and safe for improving shoulder ROM across treatment modalities. Surgeon preference may effectively guide treatment independent of diabetic status., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Schoch et al.)
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- 2020
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177. A retrospective review of revision proximal humeral allograft-prosthetic composite procedures: an analysis of proximal humeral bone stock restoration.
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Reif T, Schoch B, Spiguel A, Elhassan B, Wright T, Sanchez-Sotelo J, and Wilke BK
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- Adolescent, Adult, Aged, Aged, 80 and over, Allografts surgery, Child, Epiphyses surgery, Female, Hemiarthroplasty, Humans, Male, Middle Aged, Reoperation methods, Retrospective Studies, Shoulder Prosthesis, Transplantation, Homologous, Young Adult, Arthroplasty, Replacement, Shoulder methods, Bone Transplantation methods, Humerus surgery, Shoulder Joint surgery
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Background: Allograft-prosthetic composite (APC) reconstruction of the proximal humerus is a technique for reconstruction of large bone deficits, provides improvement in pain and function, and is thought to restore bone if revision surgery is needed. The purpose of this study was to evaluate the ability of proximal humeral APCs to restore usable bone at the time of revision surgery., Methods: Two institutional electronic medical records were reviewed to evaluate proximal humeral APC procedures performed between 1970 and 2018. We identified 115 cases, of which 14 underwent revision for aseptic causes. The indications for revision included nonunion (n = 7), glenohumeral instability (n = 5), and allograft fracture (n = 2). Three categories were used to classify the amount of usable allograft retained at revision surgery: type A, complete allograft retention; type B, partial retention; and type C, no retention., Results: A total of 14 patients (6 male and 8 female patients) underwent revision of the APC reconstruction at a mean of 22.8 months. At revision, allograft retention was classified as type A in 6 shoulders, type B in 3, and type C in 5. Type A cases were associated with nonunion with a well-fixed stem, type B cases were associated with instability and were converted from a hemiarthroplasty to a reverse total shoulder arthroplasty, and type C cases were associated with an allograft fracture or nonunion with a loose humeral component., Conclusion: A substantial number of revisions of proximal humeral APC reconstructions maintain a portion of the allograft bone (64.3%). This study supports the ongoing use of the APC reconstruction technique for large bone deficits., (Copyright © 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
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- 2020
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178. Latarjet with cortical button fixation is associated with an increase of the risk of recurrent dislocation compared to screw fixation.
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Hardy A, Sabatier V, Schoch B, Vigan M, and Werthel JD
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- Adolescent, Adult, Arthroplasty, Female, Humans, Male, Middle Aged, Recurrence, Reoperation, Retrospective Studies, Risk, Tomography, X-Ray Computed, Young Adult, Arthroscopy methods, Bone Screws, Joint Instability surgery, Shoulder Dislocation surgery, Shoulder Joint surgery
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Purpose: The purpose of this study was to compare the clinical results of the Latarjet procedure using two cortical buttons vs two screws. It was hypothesized that cortical button would result in similar rates of recurrent dislocations, but a lower rate of reoperation compared to screw fixation., Methods: A retrospective comparative case-cohort analysis was performed for all patients undergoing a Latarjet procedure for recurrent anterior glenohumeral instability. Patient demographics, number of dislocations prior surgery, arm dominance, shoulder hyperlaxity, level of sport, type of sport and ISIS score were collected. Shoulders were separated into two groups based on surgical fixation (screws vs cortical button). Postoperatively, shoulders were evaluated for recurrent dislocation, revision surgery, post-operative Walch-Duplay score, and the Simple shoulder test (SST). Two hundred and thirty-six patients were included in the screw fixation group (group A) and 72 in button fixation group (group B) and were evaluated at a mean follow-up of 3.4 ± 0.8 years. Demographics of the two groups were similar with the exception of operative side hand dominance, which was more common in group B [50 (69.4%) vs 128 (54.2%), p = 0.02]., Results: Recurrent dislocation was significantly lower in Group A: 6 (2.5%) vs 6(8.3%) (p = 0.02). Reoperation was more common in group A [14 (5.9%) vs 0 (0%)]. At follow-up, Walch-Duplay scores and simple shoulder tests were similar in both groups., Conclusion: Button fixation for Latarjet showed higher rates of recurrent dislocation compared to screw fixation. However, the increased stability afforded by screw fixation needs to be weighed against the increased risk of reoperation for hardware prominence., Level of Evidence: III.
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- 2020
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179. Batter's Shoulder: Clinical Outcomes and Return to Sport.
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OKeefe KJ, Haupt E, Thomas WC, King J 3rd, Moser M, Farmer KW, and Schoch B
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Background Batter's shoulder has been defined as an acute posterior subluxation of the lead shoulder during a baseball swing causing a traumatic tear of the posterior labrum. There are limited data correlating repair techniques with return-to-play information but none utilizing standardized outcome measures. The purpose of this study is to examine a case series of patients for postoperative return-to-play and obtain follow-up using standardized outcome measures. Methods We retrospectively identified 10 patients with a batter's shoulder injury. Patients were included if they met the criteria for batter's shoulder injury. We attempted contact via telephone to complete Western Ontario Shoulder Instability (WOSI) and Disability of Arm Shoulder and Hand (QuickDASH) evaluations. We successfully reached five of the patients. The minimum follow-up was one year and the maximum was 11 years. Results All five patients in our cohort were able to return to play at the previous level without limitation. Patients reported a very low percentage limitation on the WOSI and QuickDASH questionnaires and results are detailed further on. Range of motion (ROM) and strength were not affected. Conclusion Batter's shoulder is an infrequent cause of posterior labral tearing, leading to a painful swing that can limit sports activity. In our limited series, all patients treated with arthroscopic repair were able to return to play at the previous level, confirming a significantly improved prognosis for a batter's shoulder injury in contrast to return to play after other causes of posterior labral tears., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2020, OKeefe et al.)
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- 2020
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180. Outcomes After Latarjet Procedure: Patients With First-Time Versus Recurrent Dislocations.
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Hardy A, Sabatier V, Laboudie P, Schoch B, Nourissat G, Valenti P, Kany J, Deranlot J, Solignac N, Hardy P, Vigan M, and Werthel JD
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- Adult, Arthroscopy, Cohort Studies, Female, Humans, Male, Paris, Recurrence, Retrospective Studies, Young Adult, Arthroplasty, Pain, Postoperative etiology, Reoperation statistics & numerical data, Shoulder Dislocation surgery
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Background: The preoperative number of dislocations has been previously proved to be a major factor influencing the results after Bankart repair with more preoperative dislocations correlated with higher recurrence rates and more reoperations. This could possibly be because of the lower quality of the tissue repaired during the procedure after multiple dislocations. On the other hand, the Latarjet procedure does not "repair" but rather reconstructs and augments the anterior glenoid., Purpose/hypothesis: The main objective was to report the clinical outcomes of patients undergoing a Latarjet procedure after 1 dislocation versus multiple (≥2) dislocations. The hypothesis was that the preoperative number of dislocations would not influence clinical results., Study Design: Cohort study; Level of evidence, 3., Methods: Patients older than 18 years who had undergone a primary Latarjet procedure for shoulder instability with at least 2 years of follow-up were included. Three different techniques were used: a mini-open technique using 2 screws, an arthroscopic technique using 2 screws, and an arthroscopic technique using 2 cortical buttons. Patients were evaluated and answered a questionnaire to assess the number of episodes of dislocation before surgery, the time between the first dislocation and surgery, recurrence of the dislocation, revision surgery, the Walch-Duplay score, the Simple Shoulder Test score, and the visual analog scale (VAS) score for pain., Results: A total of 308 patients were included for analysis with a mean follow-up of 3.4 ± 0.8 years. Of that, 83 patients were included in the first-time dislocation group and 225 in the recurrent dislocation group. At last follow-up, the rates of recurrence and reoperation were not significantly different between groups: 4.8% in the first-time dislocation group versus 3.65% in the recurrent dislocation group and 6.1% versus 4.0%, respectively. The overall Walch-Duplay scores at last follow-up were also comparable between the 2 groups, 67.3 ± 24.85 and 71.8 ± 25.1, even though the first-time dislocation group showed a lower pain subscore (15.0 ± 8.6 vs 18.0 ± 7.5; P = .003). The VAS for pain was also significantly higher in the first-time dislocation group compared with the recurrent dislocation group (1.8 ± 2.3 vs 1.2 ± 1.7; P = .03)., Conclusion: The number of episodes of dislocation before surgery does not affect postoperative instability rates and reoperation rates after the Latarjet procedure. However, patients with first-time dislocations had more postoperative pain compared with patients with recurrent dislocations before surgery.
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- 2020
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181. Outcomes of the Latarjet Procedure for the Treatment of Chronic Anterior Shoulder Instability: Patients With Prior Arthroscopic Bankart Repair Versus Primary Cases.
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Werthel JD, Sabatier V, Schoch B, Amsallem L, Nourissat G, Valenti P, Kany J, Deranlot J, Solignac N, Hardy P, Vigan M, and Hardy A
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- Adult, Cohort Studies, Female, Humans, Male, Paris, Recurrence, Retrospective Studies, Young Adult, Arthroplasty, Arthroscopy, Reoperation statistics & numerical data, Shoulder Dislocation surgery
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Background: It remains unclear whether results differ between a Latarjet procedure performed after a failed arthroscopic Bankart repair and one performed as the primary operation., Purpose: To compare the postoperative outcomes of the Latarjet procedure when performed as primary surgery and as revision for a failed arthroscopic Bankart repair., Study Design: Cohort study; Level of evidence, 3., Methods: A multicenter retrospective comparative case-cohort analysis was performed for all patients undergoing a Latarjet procedure for recurrent anterior shoulder instability. Patients were separated into 2 groups depending on if the Latarjet procedure was performed after a failed arthroscopic Bankart repair (group 1) or as the first operation (group 2). Outcome measures included recurrent instability, reoperation rates, complications, pain, Walch-Duplay scores, and Simple Shoulder Test., Results: A total of 308 patients were eligible for participation in the study; 72 (23.4%) did not answer and were considered lost to follow-up, leaving 236 patients available for analysis. Mean follow-up was 3.4 ± 0.8 years. There were 20 patients in group 1 and 216 in group 2. Despite similar rates of recurrent instability (5.0% in group 1 vs 2.3% in group 2; P = .5) and revision surgery (0% in group 1 vs 6.5% in group 2; P = .3), group 1 demonstrated significantly worse pain scores (2.56 ± 2.7 vs 1.2 ± 1.7; P = .01) and patient-reported outcomes (Walch-Duplay: 52 ± 25.1 vs 72.2 ± 25.0; P = .0007; Simple Shoulder Test: 9.3 ± 2.4 vs 10.7 ± 1.9; P = .001) when compared with those patients undergoing primary Latarjet procedures., Conclusion: Functional outcome scores and postoperative pain are significantly worse in patients undergoing a Latarjet procedure after a failed arthroscopic Bankart repair when compared with patients undergoing primary Latarjet. The assumption that a failed a Bankart repair can be revised by a Latarjet with a similar result to a primary Latarjet appears to be incorrect. Surgeons should consider these findings when deciding on the optimal surgical procedure for recurrent shoulder instability.
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- 2020
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182. The V-Sign: A Simple Radiographic Sign of Shoulder Subluxation.
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Schoch B, Smitherman A, Horodyski MB, Struk A, King JJ 3rd, Farmer KW, and Wright T
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Introduction Shoulder subluxation is a common finding associated with orthopedic pathology. This study assesses the inter- and intra-observer reliability of a new radiographic sign used to identify glenohumeral subluxation. Methods Shoulders of 55 consecutive patients presenting with shoulder pain were reviewed for the presence of a "V-sign". Three shoulder surgeons reviewed all radiographs at three separate time periods in a randomized fashion. Inter- and intra-observer reliabilities were calculated. Results The V-sign was identified in 26 (47%) shoulders. Intra-rater reliability was satisfactory for all the three surgeons, with kappa values of 0.85, 0.78, and 0.77, respectively. Inter-rater reliability was similarly satisfactory, with a value of 0.71. The surgeons demonstrated 100% agreement on the direction of subluxation when a V-sign was documented. Discussion The V-sign is a reproducible radiographic sign that can be used to detect glenohumeral subluxation in patients presenting with shoulder pain., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2019, Schoch et al.)
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- 2019
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183. Preoperative parameters that predict postoperative patient-reported outcome measures and range of motion with anatomic and reverse total shoulder arthroplasty.
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Friedman RJ, Eichinger J, Schoch B, Wright T, Zuckerman J, Flurin PH, Bolch C, and Roche C
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Background: Preoperative factors that most influence postoperative outcomes of both anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA) are unknown. The purpose of this study was to identify the preoperative parameters that significantly influence postoperative outcomes of aTSA and rTSA., Methods: The outcomes of 1089 aTSA patients and 1332 rTSA patients (mean follow-up period, 49 months) from an international registry with a single platform system were analyzed. A multiple linear regression model with backward stepwise selection identified the preoperative parameters that were significant predictors of postoperative clinical outcome metric scores and motion measures for both rTSA and aTSA., Results: For both aTSA and rTSA patients, numerous preoperative parameters that influence postoperative outcomes were identified. Greater postoperative range of motion (ROM) was significantly influenced by greater preoperative ROM. For aTSA, greater postoperative American Shoulder and Elbow Surgeons (ASES) scores were significantly influenced by greater preoperative ASES scores, no history of shoulder surgery, and the presence of greater preoperative active external rotation. For rTSA, greater postoperative ASES scores were significantly influenced by greater preoperative ASES scores, no history of shoulder surgery, no history of tobacco use, less preoperative passive external rotation, and greater preoperative active external rotation., Conclusions: This study quantified the preoperative predictors of postoperative clinical outcome metric scores and ROM for both aTSA and rTSA. Numerous significant associations were identified, including demographic and comorbidity risk factors. These associations may be helpful for surgeons to consider when counseling patients regarding aTSA versus rTSA and to establish more accurate expectations prior to surgery., (© 2019 The Authors.)
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- 2019
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184. Does Prolonged Use of Walkers in Shoulder Arthroplasty Patients Lead to Accelerated Failure Rates?
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McLendon P, Schoch B, Cofield R, Sanchez-Sotelo J, and Sperling J
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Introduction: The effect of weight-bearing on a shoulder arthroplasty (SA) remains unclear, and recommendations regarding the use of a walker in SA patients have not been established. The purpose of this study was to determine outcomes and survivorship of SA in patients who routinely use a walker., Methods: Fifty-three primary SA (10 hemiarthroplasties (HAs), 33 anatomic total shoulder arthroplasties (TSAs), 10 reverse shoulder arthroplasties (RSAs)) in 41 walker-dependent patients were followed for a minimum of three years (mean 64 months, range, 36-156). The average age at SA was 76 years. Shoulders were assessed for pain, range of motion (ROM), satisfaction, Neer ratings, American Shoulder and Elbow Surgeons (ASES) score, complications, survivorship, and radiographic outcomes., Results: At most recent follow-up, 40 shoulders (75%) were pain free, elevation and external rotation improved significantly (P < .0001), and 87% of the patients were satisfied. Postoperative ASES scores averaged 74 (range, 38-92) points. There were 25 excellent, 16 satisfactory, and 12 unsatisfactory results based on modified Neer ratings. Four shoulders (7.5%) required reoperation at a mean of 40 months after the index arthroplasty. Radiographically, there were six cases of glenoid loosening in the anatomic SA group (25%), and two cases of severe glenoid erosion in the HA group (25%)., Conclusion: Routine use of a walker does not appear to lead to a markedly increased rate of SA failure at mid-term follow-up. Concerning radiographic findings were more common after HA and anatomic TSA than after RSA. Longer follow-up is required to determine the long-term impact of walker use on SA., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2019, McLendon et al.)
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- 2019
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185. Outcomes After Hemiarthroplasty of the Elbow for the Management of Posttraumatic Arthritis: Minimum 2-Year Follow-up.
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Werthel JD, Schoch B, Adams J, and Steinmann S
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- Adolescent, Adult, Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Male, Middle Aged, Osteoarthritis etiology, Reoperation, Retrospective Studies, Young Adult, Elbow Injuries, Arthroplasty, Replacement, Elbow methods, Elbow Joint surgery, Hemiarthroplasty methods, Osteoarthritis surgery
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Background: Hemiarthroplasty (HA) of the elbow represents an alternative to total elbow arthroplasty (TEA) without the associated activity restrictions. This study reviews our experience with distal humerus HA with minimum 2-year follow-up., Methods: Between 2002 and 2012, 16 elbows underwent HA for posttraumatic arthritis of the elbow. Patients were followed for a minimum of 2 years or until revision surgery. Outcome measures included pre- and postoperative Mayo Elbow Performance Scores (MEPSs), complications, and revisions., Results: Mean age at arthroplasty was 45 years, and follow-up averaged 51 months. All patients had previously undergone one or more surgical procedures at the elbow (average of 1.5 procedures). At follow-up, five had undergone additional surgery; two were revised to TEA. In surviving implants, the range of motion at follow-up was markedly improved from preoperative motion. The MEPS for the remaining HA included five excellent results, three good results, five fair results, and one poor result., Discussion: Elbow HA is an option for young or active patients with end-stage elbow posttraumatic arthritis who are unwilling to accept activity limitations. However, high rates of revision surgery and revision to TEA occur after HA for posttraumatic osteoarthritis of the elbow. Only 57% of patients with surviving implants had a good to excellent MEPS, although improvement in the range of motion was predictable.
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- 2019
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186. Outcomes of Uncemented Versus Cemented Reverse Shoulder Arthroplasty for Proximal Humerus Fractures.
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Schoch B, Aibinder W, Walters J, Sperling J, Throckmorton T, Sanchez-Sotelo J, and Duquin T
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- Aged, Aged, 80 and over, Bone Cements therapeutic use, Female, Humans, Male, Middle Aged, Patient Reported Outcome Measures, Postoperative Complications physiopathology, Postoperative Complications surgery, Range of Motion, Articular physiology, Retrospective Studies, Shoulder Fractures physiopathology, Treatment Outcome, Arthroplasty, Replacement, Shoulder methods, Shoulder Fractures surgery
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Reverse shoulder arthroplasty (RSA) for proximal humerus fractures (PHFs) is traditionally performed with cemented humeral fixation. The purpose of this study was to compare the clinical and radiographic outcomes of cemented and cementless RSA for PHF. Between 2010 and 2014, 38 acute PHFs were treated with RSA and followed for a minimum of 2 years (mean, 37 months; range, 24-66 months). The mean time from fracture to RSA was 7 days (range, 1-30 days). Humeral stems were cemented in 19 shoulders and uncemented in 19 shoulders. Outcome measures included visual analog scale pain scores, range of motion, postoperative Quick Disabilities of the Arm, Shoulder and Hand scores, American Shoulder and Elbow Surgeons scores, and radiographic parameters. The 2 groups had similar visual analog scale pain scores, postoperative range of motion, and Quick Disabilities of the Arm, Shoulder and Hand scores (P>.05). American Shoulder and Elbow Surgeons scores and satisfaction scores were significantly higher with cemented humeral fixation (76.3 vs 48.0, P=.005; 1.2 vs 1.8, P=.04). Radiographically, there was no difference in terms of tuberosity healing, component loosening, or notching (P>.05). Reverse shoulder arthroplasty provides pain relief for PHF, regardless of humeral fixation. In this cohort, cementless fixation was associated with worse patient-reported outcomes, although no correlation could be established with pain, motion, or tuberosity healing. Further studies are required before cementless fixation can be recommended for RSA for fracture. [Orthopedics. 2019; 42(2):e236-e241.]., (Copyright 2019, SLACK Incorporated.)
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- 2019
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187. Arthroscopic Trillat Coracoid Transfer Procedure Using a Cortical Button for Chronic Anterior Shoulder Instability.
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Valenti P, Maroun C, Schoch B, Arango SO, and Werthel JD
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The Trillat procedure has been proposed to treat chronic anterior shoulder instability by performing a closing wedge osteotomy of the coracoid process fixed with a coracoscapular screw above the subscapularis. The goal of this osteotomy is to distalize and medialize the coracoid tip to place the conjoint tendon in front of the glenohumeral joint. This in turn distalizes and reinforces the subscapularis in abduction and allows the conjoint tendon to act as a sling and push the humeral head posteriorly. It is commonly accepted to perform this surgery for patients with chronic shoulder anterior instability associated with massive irreparable rotator cuff tear (to preserve and retension the residual subscapularis muscle) or in patients with anterior instability and hyperlaxity. We present a less invasive arthroscopic technique for this procedure. This arthroscopic technique allows assessment and treatment of associated lesions and allows for intraoperative assessment of the subscapularis after the coracoid process is moved to prevent subcoracoid impingement and loss of external rotation.
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- 2019
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188. Validation of Neck-Shaft Angle Correction After Cephalomedullary Nail Fixation.
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Parry JA, Barrett I, Schoch B, Cross W, and Yuan B
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- Arthrometry, Articular methods, Bone Nails, Humans, Models, Educational, Rotation, Sensitivity and Specificity, Femur Neck injuries, Fracture Fixation, Intramedullary methods, Hip Fractures diagnostic imaging, Hip Fractures surgery, Range of Motion, Articular physiology
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Objectives: To validate a neck-shaft angle (NSA) correction formula using the known angle between the medullary nail and lag screw of an indwelling cephalomedullary nail (CMN)., Methods: Pertrochanteric femur fractures were created in 7 synthetic femurs and reconstructed with a CMN. Anteroposterior x-rays were taken with the proximal femur in 0, 15, 30, and 45 degrees of internal/external rotation and 10 and 20 degrees of flexion with neutral rotation. The femoral NSA and the nail angle were measured on anteroposterior x-rays. The corrected NSA was obtained by multiplying the known nail angle by the quotient of the measured NSA over the measured nail angle., Results: With increasing degrees of internal or external rotation, the difference between the actual and the measured NSA increased. After correction using the known angle of the nail, the measured NSA was reduced to within 3 degrees of the actual NSA over all degrees of rotation. At neutral rotation, 15 degrees of external rotation, and 10 and 20 degrees of hip flexion, there was minimal difference between the actual NSA and the measured NSA, negating the effect of the correction formula., Conclusions: The measured NSA after CMN of intertrochanteric fractures is altered by hip rotation. This study validates the correction formula, which determines this difference by using the known angle between the lag screw and the nail.
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- 2018
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189. Shoulder Arthroplasty for Sequelae of Obstetrical Brachial Plexus Injury.
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Werthel JD, Schoch B, Frankle M, Cofield R, and Elhassan BT
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- Aged, Arthritis etiology, Birth Injuries complications, Brachial Plexus Neuropathies surgery, Female, Follow-Up Studies, Humans, Male, Middle Aged, Range of Motion, Articular, Registries, Rotation, Shoulder Pain surgery, Visual Analog Scale, Arthritis surgery, Arthroplasty, Replacement, Shoulder, Brachial Plexus injuries, Brachial Plexus Neuropathies complications, Hemiarthroplasty, Shoulder Joint surgery
- Abstract
Purpose: Shoulder arthroplasty following obstetrical brachial plexus injury (OBPI) is technically challenging because glenoid morphology, muscle balance, and humeral version are substantially altered compared with the neurologically intact shoulder. The purpose of this study is to report the outcome of shoulder arthroplasty in a group of patients with end-stage arthritis secondary to OBPI., Materials and Methods: Seven patients with OBPI and secondary glenohumeral arthritis were treated with shoulder arthroplasty between 1976 and 2014. Two underwent hemiarthroplasty (HA), 2 underwent total shoulder arthroplasty (TSA), and 3 underwent reverse shoulder arthroplasty (RSA). One HA was lost to follow-up and was excluded. The remaining 6 patients (mean age, 62.5 years old at the time of surgery) were followed for a minimum of 2 years (mean, 7.5 years; range, 2-13 years) Outcome measures included pain, range of motion, and postoperative modified Neer ratings., Results: Pain improved in all shoulders. Mean forward flexion was unchanged. No shoulders treated with HA/TSA regained forward elevation above 90°, compared with 1 out of the 3 RSAs. External rotation improved from a mean of -10° to 20°. Active internal rotation decreased from L1 to L5. Immediate postoperative radiographs showed either severe posterior or posterosuperior subluxation in all 3 patients treated with nonconstrained implants., Conclusions: Shoulder arthroplasty is an acceptable option to relieve pain in patients with symptomatic shoulder arthritis as a sequel of OBPI. However, range of motion improvements are not expected., Type of Study /level of Evidence: Therapeutic V., (Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)
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- 2018
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190. Hemiarthroplasty Is an Option for Patients Older Than 70 Years With Glenohumeral Osteoarthritis.
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Werthel JD, Schoch B, Adams JE, Schleck C, Cofield R, and Steinmann SP
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- Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Male, Operative Time, Osteoarthritis complications, Pain, Postoperative etiology, Range of Motion, Articular, Reoperation, Retrospective Studies, Rotation, Shoulder Joint physiopathology, Shoulder Pain etiology, Time Factors, Treatment Outcome, Arthroplasty, Replacement, Shoulder adverse effects, Hemiarthroplasty adverse effects, Osteoarthritis surgery, Shoulder Joint surgery
- Abstract
Hemiarthroplasty (HA) of the shoulder has several potential advantages over total shoulder arthroplasty (TSA), particularly in the elderly population. This study reviewed long-term results of HA and TSA in patients older than 70 years with glenohumeral osteoarthritis. During a 30-year period, 403 shoulders had undergone HA (n=74) or TSA (n=329) for glenohumeral osteoarthritis. Outcome measures included pain, range of motion, and postoperative modified Neer ratings. All patients were included in the mortality and revision analyses. A total of 289 shoulders (44 HAs and 245 TSAs; mean patient age, 75 years) with a minimum of 5 years of follow-up or follow-up until revision were included. Both groups showed significant improvements in pain, abduction, and external rotation. No significant differences were detected between groups in postoperative pain, range of motion, or modified Neer ratings. Operative time was significantly lower in the HA group. There was no statistically significant difference detected in implant revision-free survival between TSA and HA (hazard ratio, 3.09) or in overall survival hazard ratio. At long-term follow-up, both HAs and TSAs provided good function in the elderly population. Patients who underwent TSA and patients who underwent HA had similar results, but the latter had a shorter operative time and lower revision rate. Hemiarthroplasty is a reasonable option for patients older than 70 years with end-stage glenohumeral osteoarthritis. [Orthopedics. 2018; 41(4):222-228.]., (Copyright 2018, SLACK Incorporated.)
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- 2018
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191. Does the Angle of the Nail Matter for Pertrochanteric Fracture Reduction? Matching Nail Angle and Native Neck-Shaft Angle.
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Parry JA, Barrett I, Schoch B, Yuan B, Cass J, and Cross W
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- Aged, Aged, 80 and over, Female, Fracture Fixation, Intramedullary methods, Humans, Middle Aged, Retrospective Studies, Treatment Outcome, Bone Nails, Femoral Fractures surgery, Fracture Fixation, Intramedullary instrumentation
- Abstract
Objectives: To determine whether fixation of pertrochanteric hip fractures with cephalomedullary nails (CMNs) with a neck-shaft angle (NSA) less than the native NSA affects reduction and lag screw cutout., Design: Retrospective comparative study., Setting: Level I trauma center., Patients/participants: Patients treated with a CMN for unstable pertrochanteric femur fractures (OTA/AO 31-A2.2 and 31-A2.3) between 2005 and 2014., Intervention: CMN fixation., Main Outcome Measurement: NSA reduction and lag screw cutout., Results: Patients fixed with a nail angle less than their native NSA were less likely to have good reductions [17% vs. 60%, 95% confidence interval (CI), -63% to -18%; P = 0.0005], secondary to more varus reductions (41% vs. 10%, 95% CI, 9%-46%; P = 0.01) and more fractures with ≥4 mm of displacement (63% vs. 35%, 95% CI, 3%-49%; P = 0.03). The cutout was not associated with the use of a nail angle less than the native NSA (60% vs. 76%, 95% CI, -56% to 18%; P = 0.5), varus reductions (60% vs. 32%, 95% CI, -13% to 62%; P = 0.3), or poor reductions (20% vs. 17%, 95% CI, -24% to 44%; P = 1.0)., Conclusions: The fixation of unstable pertrochanteric hip fractures with a nail angle less than the native NSA was associated with more varus reductions and fracture displacement but did not affect the lag screw cutout., Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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- 2018
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192. Not All Polyaxial Locking Screw Technologies Are Created Equal: A Systematic Review of the Literature.
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Schoch B, Hast MW, Mehta S, and Namdari S
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- Humans, Bone Screws, Fracture Fixation instrumentation
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Background: Locking plate fixation strength relies on axial alignment of the screw axis and plate hole, with small deviations in alignment substantially decreasing the load to failure. In an effort to overcome this technical deficiency, polyaxial locking plates were designed to provide increased flexibility of screw positioning with the intent of not sacrificing fixation strength. The purpose of this article is to review the variety of polyaxial locking mechanisms currently available, to compare the biomechanical performance of these designs, and to highlight their differences, which may have clinical implications., Methods: A systematic review using the search terms "polyaxial locking," "variable angle locking," "polyaxial screws," and "variable angle screws" was conducted to identify all English-language articles assessing variable-angle locking screw technology. All articles directly comparing the biomechanical performance of polyaxial locking technologies were included., Results: Polyaxial locking is achieved by 5 described mechanisms: point-loading thread-in, cut-in, locking cap, expansion bushing, and screw-head expansion. With increasing insertion angulation, point-loading thread-in and cut-in designs demonstrate reduced failure strength. However, locking-cap fixation maintains consistent failure strength with increasing off-axis insertion angles., Conclusions: Reports comparing polyaxial locking technologies are limited. The current biomechanical literature raises concerns that these mechanisms have various strengths and performance characteristics. Based on the results of the few studies that exist, it appears that locking-cap fixation provides superior biomechanical strength when compared with point-loading and cut-in designs. Additional studies are needed to assess variable-angle locking mechanisms more completely.
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- 2018
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193. Surgical Fixation of Periprosthetic Humerus Fractures Using an Extension Plate: Surgical Technique and Report of 5 Cases.
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Schoch B, Mehta S, and Namdari S
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- Aged, Aged, 80 and over, Arthroplasty, Replacement, Shoulder adverse effects, Female, Humans, Humerus diagnostic imaging, Male, Periprosthetic Fractures diagnosis, Radiography, Shoulder Fractures diagnosis, Shoulder Injuries, Treatment Outcome, Bone Plates, Fracture Fixation, Internal methods, Humerus surgery, Periprosthetic Fractures surgery, Shoulder Fractures surgery, Shoulder Joint surgery
- Abstract
Periprosthetic fractures after shoulder arthroplasty occur in up to 2% of patients. In patients with stable components who fail or cannot undergo nonoperative management, stable fixation is required. We present a new technique to obtain proximal fixation around the humeral component using a 4.5-mm large fragment plate and a 3.5-mm attachment plate.
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- 2017
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194. Shoulder arthroplasty in patients with osteo-chondrodysplasias.
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Schoch B, Werthel JD, Sanchez-Sotelo J, Sperling JW, Cofield RH, and Morrey M
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- Adolescent, Adult, Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Male, Middle Aged, Osteochondrodysplasias complications, Range of Motion, Articular, Reoperation statistics & numerical data, Retrospective Studies, Shoulder Joint pathology, Shoulder Pain surgery, Treatment Outcome, Arthroplasty, Replacement, Shoulder methods, Osteochondrodysplasias surgery, Shoulder Joint surgery
- Abstract
Purpose: Osteo-chondrodysplasias are a rare cause of limb malalignment, deformity and degenerative joint disease. Earlier in life, deformities may be managed with bony realignment and soft tissue releases; however, as degenerative changes progress, arthroplasty may be considered. There are limited reports examining shoulder arthroplasty in this population. This study aims to assess pain relief, function, and re-operation rate of shoulder arthroplasty in patients with osteo-chondrodysplasias., Methods: Between January 1984 and December 2012, 13 shoulders with end-stage arthritis secondary to osteo-chondrodysplasia underwent shoulder arthroplasty. Three were treated with hemiarthroplasty (HA), nine with anatomic total shoulder arthroplasty (TSA), and one with a reverse total shoulder arthroplasty (RSA). All shoulders were followed for two years or until reoperation (mean 7.9 years, range 2-25)., Results: Shoulder arthroplasty significantly improved pain, elevation, external rotation, and internal rotation. All but one patient considered their shoulder to be better than pre-operatively; however, only two shoulders received an excellent Neer rating. Seven shoulders had satisfactory Neer ratings and four unsatisfactory. One TSA was converted to a RSA for aseptic glenoid loosening at 9.5 years (re-operation rate 8%)., Discussion: Pain relief and improved function can be expected in patients with osteo-chondrodysplasias despite challenging anatomy. Unlike the only previous case series reporting a 31% revision rate at mean follow-up of seven years, our series shows the incidence of failure to be much lower., Conclusions: With the advent of smaller humeral components, the need for custom implants may not be necessary, and surgeons may intervene earlier and more confidently in this population., Level of Evidence: IV case series.
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- 2017
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195. Results of Total Elbow Arthroplasty in Patients Less Than 50 Years Old.
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Schoch B, Wong J, Abboud J, Lazarus M, Getz C, and Ramsey M
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- Adult, Age Factors, Arthritis diagnostic imaging, Arthritis etiology, Elbow Prosthesis, Female, Humans, Male, Middle Aged, Prosthesis Failure, Retrospective Studies, Treatment Outcome, Young Adult, Arthritis surgery, Arthroplasty, Replacement, Elbow
- Abstract
Purpose: Total elbow arthroplasty (TEA) is a treatment option for end-stage arthritis in low-demand patients willing to accept the limitations of TEA. Concern remains regarding the longevity of TEA implants, especially in younger patients. The purpose of this study was to determine the failure rate and complication profile of TEA performed in patients aged less than 50 years., Methods: Between 2009 and 2013, 11 linked TEAs were performed in patients aged less than 50 years (mean age, 37 years; range, 22-47 years). Outcome measures included pain; range of motion; Disabilities of the Arm, Shoulder, and Hand scores; Mayo Elbow Performance scores; complications; and reoperations. Elbows were observed for a minimum of 2 years or until mechanical failure. Mean follow-up was 3.2 years., Results: At follow-up, 82% of TEAs had experienced a complication. Six elbows sustained mechanical failures (5 had ulnar loosening and one had humeral loosening). Pain improved from 8.0 to 4.9. Extension improved from 34° to 22° and flexion increased from 113° to 128°. Mean Disabilities of the Arm, Shoulder, and Hand score for surviving implants at follow-up was 42.9 (range, 17.5-56.7). Mayo Elbow Performance scores for surviving implants were rated as excellent (2), good (1), and fair (2)., Conclusions: High rates of early mechanical failure, predominately ulnar loosening, were observed in TEA in patients aged less than 50 years. Surgeons should remain cautious in performing TEA in young patients who can be expected to use the TEA in a more demanding fashion, placing them at higher risk for mechanical failure., Type of Study/level of Evidence: Therapeutic V., (Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)
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- 2017
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196. Glenohumeral Mismatch in Anatomic Total Shoulder Arthroplasty.
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Schoch B, Abboud J, Namdari S, and Lazarus M
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- Biomechanical Phenomena, Glenoid Cavity anatomy & histology, Humans, Humeral Head anatomy & histology, Muscle Contraction physiology, Range of Motion, Articular physiology, Arthroplasty, Replacement, Shoulder methods, Glenoid Cavity surgery, Humeral Head surgery, Muscle, Skeletal physiopathology, Prosthesis Fitting adverse effects, Prosthesis Fitting methods, Shoulder Prosthesis adverse effects
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- 2017
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197. Radiographic outcomes of single versus dual plate fixation of acute mid-shaft clavicle fractures.
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Chen X, Shannon SF, Torchia M, and Schoch B
- Subjects
- Adult, Female, Humans, Male, Retrospective Studies, Bone Plates, Clavicle injuries, Fracture Fixation, Internal methods, Fractures, Bone surgery, Open Fracture Reduction methods
- Abstract
Introduction: The clavicle exhibits considerable movement in three planes making rigid fixation challenging. The addition of a second plate may be considered to improve fixation rigidity, but risks compromising the blood supply to the fracture site. The purpose of this study is to assess if extraperiosteal dual plate fixation increases the rate of non-union, reoperation, and complications at 1 year for surgically treated acute mid-shaft clavicle fractures., Methods: Between June 1998 and June 2013, surgically treated mid-shaft clavicle fractures undergoing open reduction internal fixation within 4 weeks of injury were retrospectively reviewed. Patients undergoing single plate fixation were compared to dual plate fixation. Patients were followed for a minimum of 1 year. Charts were reviewed to assess union rates, reoperation, and complications., Results: One hundred and sixty-three clavicles (125 single plates, 34 dual plates) were evaluated. All patients (100%) in dual plating group and one hundred and fourteen (91%) in single plating group obtained bony union by 1 year (p = 0.13). Six patients (4.8%) experienced a non-union in the single plating cohort compared to the dual plating cohort who had a 100% union rate. Seven patients required reoperation in the single plate cohort due to implant failure (N = 4), infection (N = 2), and non-union (N = 1)., Conclusions: This limited series of patients demonstrates dual plate fixation is a reliable option for acute mid-shaft clavicle fractures, with excellent union rates and low complication rates. Compared to single plate fixation, no significant differences in outcomes were identified. In the case of more complex fracture patterns, application of a second extraperiosteal plate may be utilized without compromising healing or increasing complication rates.
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- 2017
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198. Optimizing follow-up after anatomic total shoulder arthroplasty.
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Schoch B, Werthel JD, Schleck CD, Harmsen WS, Sperling J, Sánchez-Sotelo J, and Cofield RH
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- Aged, Female, Follow-Up Studies, Humans, Male, Middle Aged, Reoperation, Retrospective Studies, Treatment Outcome, Arthroplasty, Replacement, Shoulder methods, Forecasting, Osteoarthritis surgery, Postoperative Complications surgery, Shoulder Joint surgery
- Abstract
Background: With increases in both total shoulder arthroplasty (TSA) volumes and patient life expectancies, the number of patients requiring follow-up after shoulder arthroplasty continues to grow exponentially. The purpose of this study is to establish a data-based follow-up schedule minimizing unnecessary patient and health care system costs without sacrificing patient care., Methods: Between January 1975 and January 2013, 2786 consecutive anatomic TSAs were performed at our institution. All shoulders undergoing reoperation/revision were reviewed to identify the common modes of failure and times to failure., Results: A total of 208 shoulders (7.5%) required reoperation. Early failure mechanisms included instability, rotator cuff tears, and infection, with 63% of these reoperations occurring within 2 years. Later failures included mechanical failures (including component loosening) and periprosthetic fractures, with no identifiable peak occurrence. After 2 years, TSA failed at an average rate 1.1% per year., Conclusions: TSA failure after 2 years is uncommon and triggers surgical intervention in approximately 1% of patients per year. Routine in-person surveillance of all patients on a scheduled basis may not be necessary and would increase patient and other health care costs. We recommend in-person visits to assess healing, direct rehabilitation, and manage soft tissue or infectious issues until 2 years, with planned, periodic patient contact by mail and radiographic evaluation of patients with poor or worsening outcomes thereafter, unless patient concerns arise or a newer implant design warrants closer clinical assessment., (Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
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- 2017
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199. Is previous nonarthroplasty surgery a risk factor for periprosthetic infection in primary shoulder arthroplasty?
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Werthel JD, Hatta T, Schoch B, Cofield R, Sperling JW, and Elhassan BT
- Subjects
- Aged, Female, Humans, Incidence, Male, Middle Aged, Reoperation, Retrospective Studies, Risk Factors, Arthroplasty, Replacement, Shoulder, Hemiarthroplasty, Prosthesis-Related Infections epidemiology, Shoulder Joint surgery, Surgical Wound Infection epidemiology
- Abstract
Background: The purpose of this study was to determine the risk of periprosthetic infection after primary shoulder arthroplasty (SA) in patients undergoing previous nonarthroplasty shoulder surgery compared with those without previous surgery., Materials and Methods: All patients undergoing primary SA at our institution between 1970 and 2012 were included in this study. The cohort consisted of 4577 patients treated with 2890 total SAs, 1233 hemiarthroplasties, and 454 reverse SAs; 813 (18%) patients had undergone prior nonarthroplasty shoulder surgery on the operative side. Patients with and without previous surgery were compared for postoperative periprosthetic infection. Univariate and multivariable analyses were used., Results: Deep postoperative infection of the shoulder was diagnosed in 68 patients (1.49%). Of the 813 patients who had undergone previous surgery, 20 (2.46%) developed a deep postoperative infection. However, of the 3764 patients who did not have previous shoulder surgery, 48 patients (1.28%) sustained deep shoulder infection. This difference was significant in both the univariate (P = .0094) and multivariate analyses (P = .0390). In addition, older age and female gender were significantly associated with a lower risk of deep postoperative infection (P = .0150 and P = .0074, respectively). A higher number of previous surgeries was also significantly associated with an increased risk of deep postoperative infection (P = .0272)., Conclusions: The risk of infection after primary SA is significantly higher in patients with a history of prior non-arthroplasty-related surgery. This finding should be discussed with the patients before their surgery, and potential preoperative and intraoperative workup should be undertaken to identify at-risk patients., (Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
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- 2017
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200. Revisions for aseptic glenoid component loosening after anatomic shoulder arthroplasty.
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Aibinder WR, Schoch B, Schleck C, Sperling JW, and Cofield RH
- Subjects
- Adult, Aged, Female, Follow-Up Studies, Humans, Joint Instability complications, Joint Instability surgery, Male, Middle Aged, Retrospective Studies, Shoulder Pain surgery, Shoulder Prosthesis, Arthroplasty, Replacement, Shoulder adverse effects, Prosthesis Failure, Reoperation, Shoulder Joint surgery
- Abstract
Background: Glenoid component loosening is a common indication for revision shoulder arthroplasty. The objective of this study is to assess the longer-term outcomes of patients undergoing revision specifically for aseptic loosening., Materials and Methods: Between 1985 and 2005, 34 revision shoulder arthroplasties were performed for aseptic glenoid loosening. Three patients were lost to follow-up. Treatment included component reimplantation in 20 shoulders (group I) or component removal with bone grafting in 11 shoulders (group II). We identified 9 cases of instability with or without rotator cuff tearing prior to revision. The mean follow-up period was 8.3 years., Results: The rate of survival free of reoperation at 10 years was 78.9% in group I and 83.9% in group II (P = .5). Pain relief occurred in 26 of 31 shoulders, with no difference between groups (P > .99). Active elevation and external rotation improved in both groups (P = .8). Five shoulders in group I had radiographically loose glenoids, with two requiring reoperation. Nine shoulders in group II had medial glenoid erosion, with two requiring reoperation for pain. There was a trend toward reoperation in those with preoperative instability (5 of 8 re-revisions)., Discussion and Conclusion: Glenoid revision surgery in the absence of infection provides satisfactory results, especially when instability is not coexisting. When glenoid bone stock permits, reimplantation of a new glenoid component in an active patient with an intact rotator cuff and no instability is reasonable. When the remaining glenoid bone will not support a new component, conversion to a hemiarthroplasty is also reasonable., (Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
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- 2017
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