Relationship of Ulnar Collateral Ligament Strain to Amount of Medial Olecranon Osteotomy

2001 ◽  
Vol 29 (6) ◽  
pp. 716-721 ◽  
Author(s):  
James R. Andrews ◽  
Erik J. H. Heggland ◽  
Glenn S. Fleisig ◽  
Nigel Zheng
Keyword(s):  
At Risk ◽  
Repeated Measures ◽  
Small Sample Size ◽  
Tensile Force ◽  
Ulnar Collateral Ligament ◽  
Small Sample ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Ligament Strain

Athletes at risk for valgus extension overload are also at risk for tears of the anterior bundle of the ulnar collateral ligament. Some athletes develop ligament tears after procedures for valgus extension overload such as posteromedial olecranon osteotomy. The amount of posteromedial olecranon that can be resected before ulnar collateral ligament strain, and risk of injury, increases is unknown. We dissected and mounted five fresh-frozen human cadaveric elbows to allow strain gauge monitoring of the ulnar collateral ligament with varying valgus stress, elbow flexion angle, and medial osteotomy. The average strain to failure was 11.96% ± 6.51%, corresponding to a load of 347.71 ± 46.42 N. The maximum tensile force recorded at failure was 416.24 N. Three-way repeated-measures analysis of variance revealed no significant change in strain with change in the amount of osteotomy for a given applied load and angle of flexion. On the basis of these data, we conclude that the effect of medial olecranon osteotomy on ulnar collateral ligament strain may be small. Small sample size, elderly specimens, and the variables inherent in the experimental setup and mathematical modeling make it difficult to extrapolate these results to in vivo behavior of the anterior ulnar collateral ligament. Further work is needed before definitive guidelines for olecranon osteotomy can be formulated.

scholarly journals Changes in Medial Elbow Joint Space When Elbow Valgus Stress Is Applied at Different Limb Positions and Loads In Vivo

2021 ◽  
Vol 9 (11) ◽  
pp. 232596712110459
Author(s):  
Kanta Yoshioka ◽  
Kanta Matsuzawa ◽  
Tomoya Ikuta ◽  
Sae Maruyama ◽  
Mutsuaki Edama
Keyword(s):  
Repeated Measures ◽  
Elbow Joint ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Sports Injury ◽  
Joint Space ◽  
Muscle Contractions ◽  
Collateral Ligament ◽  
Valgus Stress

Background: Ulnar collateral ligament (UCL) injury is a common sports injury among overhead-throwing athletes and causes medial elbow pain and instability. UCL injury is generally diagnosed based on symptoms, physical findings, and image evaluation. To standardize the method for evaluating elbow valgus instability, more information is needed regarding changes in the medial elbow joint space (JS) in healthy elbows. Purpose/Hypothesis: The purpose of this study was to measure the JS during the application of elbow valgus stress at different elbow flexion angles and loads and to clarify the presence of defensive muscle contractions during elbow valgus stress. It was hypothesized that the JS will differ according to different limb positions and loads and that defensive contractions will occur when elbow valgus stress is >90 N. Study Design: Controlled laboratory study. Methods: Elbow joints on the nondominant side were examined in 20 healthy male university students (mean age, 21 ± 0.2 years) at 30°, 60°, and 90° of elbow flexion. To create valgus stress on the elbow, loads of 30, 60, 90, 120, and 150 N were applied with a Telos stress device and with gravity stress on the forearm. The medial JS was measured ultrasonographically during the application of elbow valgus stress. Electrodes were attached to the pronator teres muscle, and defensive muscle contractions were measured using electromyography during the application of elbow valgus stress. Repeated-measures analysis of variance and paired t tests were used to compare the JS at each elbow angle and each valgus stress load, and the Bonferroni method was used as a post hoc test. Results: At 30° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 or 30 N ( P ≤ .018 for all). At 60° of flexion, the JS was significantly higher at 30 N versus 0 N, at 60 N versus 0 and 30 N, and at 90 N versus 0, 30, and 60 N ( P ≤ .024 for all). At 90° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 and 30 N ( P ≤ .028 for all). Defensive muscle contraction did not occur at any elbow flexion angles at elbow valgus stress ≤60 N. Conclusion: The lack of muscular contraction at elbow valgus stress ≤60 N may reflect the function of the medial collateral ligament. Clinical Relevance: Elbow valgus stress ≤60 N allows for the evaluation of the joint opening.

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

scholarly journals In vivo assessment of a single adenine mutation in 5′UTR of Endothelin-1 gene in paediatric cases with severe pulmonary hypertension: an observational study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Abhishek Kumar ◽  
Minati Choudhury ◽  
Sakshi Dhingra Batra ◽  
Kriti Sikri ◽  
Anushree Gupta
Keyword(s):  
Pulmonary Hypertension ◽  
Congenital Heart ◽  
Small Sample Size ◽  
Small Sample ◽  
Severe Pulmonary Hypertension ◽  
Endothelin 1 ◽  
Circulating Levels ◽  
In Vivo Assessment

Abstract Objective Endothelin-1 plays an important role in the pathogenesis of severe pulmonary hypertension. The + 139 ‘A’, adenine insertion variant in 5′UTR of edn1 gene has been reported to be associated with increased expression of Endothelin-1 in vitro. The aim of present study was to explore the association of this variant with the circulating levels of Endothelin-1 in vivo using archived DNA and plasma samples from 38 paediatric congenital heart disease (cyanotic and acyanotic) patients with severe pulmonary hypertension. Results The plasma Endothelin-1 levels were highly varied ranging from 1.63 to75.16 pg/ml. The + 139 ‘A’ insertion variant in 5′UTR of edn1 was seen in 8 out of 38 cases with only one acyanotic sample demonstrating homozygosity of inserted ‘A’ allele at + 139 site (4A/4A genotype). The plasma Endothelin-1 levels in children with homozygous variant 3A/3A genotype were comparable in cyanotic and acyanotic groups. Lone 4A/4A acyanotic sample had ET-1 levels similar to the median value of ET-1 associated with 3A/3A genotype and was absent in cyanotic group presumably due to deleterious higher ET-1 levels. The discussed observations, limited by the small sample size, are suggestive of homozygous adenine insertion variant posing a risk in cyanotic babies with Severe Pulmonary Hypertension.

scholarly journals Effect of Ulnar Collateral Ligament Reconstruction on Pitch Accuracy, Velocity, and Movement in Major League Baseball Pitchers

2020 ◽  
Vol 8 (12) ◽  
pp. 232596712096853
Author(s):  
Braden McKnight ◽  
Nathanael D. Heckmann ◽  
Xiao T. Chen ◽  
Kevork Hindoyan ◽  
J. Ryan Hill ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Major League Baseball ◽  
Ulnar Collateral Ligament ◽  
Poor Performance ◽  
Return To Play ◽  
Collateral Ligament ◽  
Level Of Evidence ◽  
Major League ◽  
The Mean ◽  
Performance Statistics

Background: Ulnar collateral ligament (UCL) reconstruction is frequently performed on Major League Baseball (MLB) pitchers. Previous studies have investigated the effects of UCL reconstruction on fastball and curveball velocity, but no study to date has evaluated its effect on fastball accuracy or curveball movement among MLB pitchers. Purpose/Hypothesis: The primary purpose of this study was to determine the effects of UCL reconstruction on fastball accuracy, fastball velocity, and curveball movement in MLB pitchers. Our hypothesis was that MLB pitchers who underwent UCL reconstruction would return to their presurgery fastball velocity, fastball accuracy, and curveball movement. The secondary purpose of this study was to determine which factors, if any, were predictive of poor performance after UCL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: MLB pitchers who underwent UCL reconstruction surgery between 2011 and 2012 were identified. Performance data including fastball velocity, fastball accuracy, and curveball movement were evaluated 1 year preoperatively and up to 3 years of play postoperatively. A repeated-measures analysis of variance with a Tukey-Kramer post hoc test was used to determine statistically significant changes in performance over time. Characteristic factors and presurgery performance statistics were compared between poor performers (>20% decrease in fastball accuracy) and non—poor performers. Results: We identified 56 pitchers with a total of 230,995 individual pitches for this study. After exclusion for lack of return to play (n = 14) and revision surgery (n = 3), 39 pitchers were included in the final analysis. The mean presurgery fastball pitch-to-target distance was 32.9 cm. There was a statistically significant decrease in fastball accuracy after reconstruction, which was present up to 3 years postoperatively ( P = .007). The mean presurgery fastball velocity of 91.82 mph did not significantly change after surgery ( P = .194). The mean presurgery curveball movement of 34.49 cm vertically and 5.89 cm horizontally also did not change significantly ( P = .937 and .161, respectively). Conclusion: Fastball accuracy among MLB pitchers significantly decreased after UCL reconstruction for up to 3 years postoperatively. There were no statistically significant differences in characteristic factors or presurgery performance statistics between poor and non--poor performers.

scholarly journals Adolescent Pitcher Fatigue: Ulnar Collateral Ligament Stress, Flexor-Pronator Mass Energy Depletion, and Correlation to Pitch Count

2021 ◽  
Vol 9 (7_suppl4) ◽  
pp. 2325967121S0024
Author(s):  
Manuel Schubert ◽  
Tariq Awan ◽  
Aaron Sciascia ◽  
Emily Pacheco ◽  
Jennifer DeMink ◽  
...  
Keyword(s):  
Grip Strength ◽  
Muscle Glycogen ◽  
Repeated Measures ◽  
Statistical Significance ◽  
Ulnar Collateral Ligament ◽  
Glycogen Storage ◽  
Collateral Ligament ◽  
Time Points ◽  
Subjective Fatigue ◽  
Forearm Flexor

Objectives: There has been a rise in elbow ulnar collateral ligament (UCL) injuries in youth pitchers over recent years. With forearm flexor-pronator mass fatigue, the dynamic stability provided could be diminished placing greater stress on the UCL. Pitch count limits have been instituted in an attempt to help curtail this rise in throwing injuries, especially in youth athletes. In order to provide more objective data regarding current pitch count limits for youth pitchers, the purpose of this pilot study was to evaluate for potential fatigue of the flexor-pronator mass by assessing changes in medial elbow laxity, noninvasively characterizing changes in muscle glycogen storage within the forearm flexor-pronator mass, and evaluating changes in subjective fatigue, strength, range of motion (ROM), pitching velocity, and accuracy with increasing number of pitches thrown by 10-year-old pitchers up to their recommended 75 pitch count limit. Methods: After appropriate power analysis, male pitchers 10 years of age were recruited for the study (n=22). Pitchers threw a total of 75 pitches divided into sets of 25 pitches, with standardized periods of rest in between throws and sets to best simulate a game. Bilateral medial elbow laxity was measured by applying 10 decanewtons of valgus force with a standardized stress device and utilizing ultrasound imaging (Figures 1A-B) prior to pitching and after each pitching set. The change in medial ulnohumeral joint distance (Figure 1C) after stress was applied was calculated from baseline without stress. Relative changes in muscle glycogen storage, detected as changes in echogenicity, within the flexor carpi radialis (FCR) and the flexor digitorum superficialis (FDS)/flexor carpi ulnaris (FCU) muscles were measured non-invasively with ultrasound-based software (Figures 1D-E) and recorded as fuel percentile. Repeated measures analysis of variance and post-hoc testing were used to determine statistical significance (alpha=0.05). Results: There were no significant differences in medial elbow laxity between arms or time points. There was a trend for similar decline in FCR fuel percentile values between each arm, indicating relative decreases in glycogen storage bilaterally. However, only the throwing arm demonstrated a statistically significant decline in fuel percentile from baseline to after 75 pitches (p=0.05). There were no statistically significant differences across time points for FDS/FCU fuel percentile values. Fatigue measurements for both arms were significantly higher at all time points compared to baseline (p≤0.03). Grip strength of the dominant arm after 75 pitches was significantly decreased compared to after 25 pitches (p=0.02). There were no statistically significant changes in other strength measurements, ROM, velocity, or accuracy between all time points. Conclusions: By the recommended 75 pitch count limit in 10-year-olds, subjective fatigue and a decrease in grip strength had occurred. Furthermore, relative glycogen storage of the flexor-pronator mass of the throwing arm decreased between pitching 50 to 75 pitches, but without an increase in medial elbow gapping. This study provides a foundation and raises questions for further objective testing of physiologic changes that occur throughout increasing pitching to better guide pitch count limits and ensure the safety of young athletes

Mesenchymal Stem Cell Therapy for Acetaminophen-Related Liver Injury: A Systematic Review and Meta-Analysis of Experimental Studies in Vivo

2021 ◽  
Vol 16 ◽  
Author(s):  
Li Wang ◽  
Yiwen Zhang ◽  
Jiajun Zhong ◽  
Yuan Zhang ◽  
Shuisheng Zhou ◽  
...  
Keyword(s):  
Systematic Review ◽  
Stem Cell ◽  
Liver Injury ◽  
Mesenchymal Stem Cell ◽  
Small Sample Size ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Small Sample ◽  
Control Group

Objective: The efficacy of mesenchymal stem cell (MSC) therapy in acetaminophen-induced liver injury has been investigated in animal experiments, but individual studies with a small sample size cannot be used to draw a clear conclusion. Therefore, we conducted a systematic review and meta-analysis of preclinical studies to explore the potential of using MSCs in acetaminophen-induced liver injury. Methods: Eight databases were searched for studies reporting the effects of MSCs on acetaminophen hepatoxicity. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used. SYRCLE’s risk of bias tool for animal studies was applied to assess the methodological quality. A meta-analysis was performed by using RevMan 5.4 and STATA/SE 16.0 software. Results: Eleven studies involving 159 animals were included according to PRISMA statement guidelines. Significant associations were found for MSCs with the levels of alanine transaminase (ALT) (standardized mean difference (SMD) − 2.58, p < 0.0001), aspartate aminotransferase (AST) (SMD − 1.75, p = 0.001), glutathione (GSH) (SMD 3.7, p < 0.0001), superoxide dismutase (SOD) (SMD 1.86, p = 0.022), interleukin 10 (IL-10) (SMD 5.14, p = 0.0002) and tumor necrosis factor-α (TNF-α) (SMD − 4.48, p = 0.011) compared with those in the control group. The subgroup analysis showed that the tissue source of MSCs significantly affected the therapeutic efficacy (p < 0.05). Conclusion: Our meta-analysis results demonstrate that MSCs could be a potential treatment for acetaminophen-related liver injury.

scholarly journals Development of AOSpine BOnE (Bone Osteobiologics and Evidence) Classification

2019 ◽  
Vol 10 (7) ◽  
pp. 871-874 ◽  
Author(s):  
Jeffrey C. Wang ◽  
S. Tim Yoon ◽  
Darrel S. Brodke ◽  
Jong-Beom Park ◽  
Patrick Hsieh ◽  
...  
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
In Vitro Studies ◽  
Level Of Evidence ◽  
Knowledge Forum ◽  
Levels Of Evidence ◽  
Published Evidence ◽  
Patient Reported

Study Design: Classification development. Objectives: The aim of our study was to develop a 3-tier classification for the levels of evidence for osteobiologics and provide a description of the principles by which osteobiologics can be evaluated. BOnE (Bone Osteobiologics and Evidence) classification evaluates each osteobiologic based on the available evidence, and if the published evidence is based on clinical, in vivo or in vitro studies. Methods: The process of establishing the BOnE classification included 5 face-to-face meetings and 2 web calls among members of the AOSpine Knowledge Forum Degenerative. Results: The 3 levels of evidence were determined based on the type of data on osteobiologics: level A for human studies, level B for animal studies, and level C for in vitro studies, with level A being the highest level of evidence. Each level was organized into 4 subgroups (eg, A1, A2, A3, and A4). Conclusions: The use and the variety of osteobiologics for spine fusion has dramatically increased over the past few decades; however, literature on their effectiveness is inconclusive. Several prior systematic reviews developed by AOSpine Knowledge Forum Degenerative reported low level of evidence primarily due to the high risk of bias, small sample size, lack of control groups, and limited patient-reported outcomes. BOnE classification will provide a universal platform for research studies and journal publications to classify a new or an existing product and will allow for creating decision-making algorithms for surgical planning.

Medial Elbow Instability Resulting From Partial Tears of the Ulnar Collateral Ligament: Stress Ultrasound in a Cadaveric Model

2020 ◽  
Vol 48 (11) ◽  
pp. 2613-2620
Author(s):  
Michael C. Ciccotti ◽  
Sommer Hammoud ◽  
Christopher C. Dodson ◽  
Steven B. Cohen ◽  
Levon N. Nazarian ◽  
...  
Keyword(s):  
Ulnar Collateral Ligament ◽  
Joint Space ◽  
Nonoperative Treatment ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Diagnostic Modality ◽  
Partial Tear ◽  
Partial Tears ◽  
Early Reconstruction ◽  
Anterior Posterior

Background: There is consensus that most complete ulnar collateral ligament (UCL) injuries in throwers would benefit from surgical intervention. Optimal treatment for partial UCL tears remains controversial. Stress ultrasonography has become a well-accepted diagnostic modality for assessing UCL injury. Hypothesis: Partial UCL tears will result in an intermediate increase in ulnohumeral joint space gapping as compared with that of an intact UCL and a complete UCL tear, but the degree of joint space gapping will vary by anatomic location of the partial tear. Study Design: Controlled laboratory study. Methods: Twenty-one cadaveric elbows were divided into 7 groups representing different anatomic locations of UCL partial tears. Partial tears were simulated by cutting 50% of the measured width of the UCL at 6 locations: distal anterior/posterior, midsubstance anterior/posterior, and proximal anterior/posterior. A seventh partial tear was created by partially elevating the undersurface of the distal UCL to simulate the radiographic “T-sign.” Valgus stress (15 daN) was applied to each cadaveric elbow at 30° of flexion using a standardized device. Each specimen was tested intact, partially torn, and completely torn. At each state, joint space was measured using stress ultrasonography, and the difference in joint space from unstressed to stressed (delta) was recorded. Results: There were 10 right and 11 left upper extremity specimens. The mean delta was 0.58 mm for the intact state and <0.75 mm in all groups. Both distal partial tear groups had mean deltas <0.75 mm, similar to intact elbows. Proximal tears and the T-sign demonstrated intermediate deltas (0.99-1.23 mm). Midsubstance partial tears demonstrated the largest deltas (1.57-2.03 mm), similar to those of the complete tears. All complete tear groups had a mean delta >1.5 mm (1.54-3.03 mm). Conclusion: These findings suggest that partial tears introduce a spectrum of instability from functionally intact to completely torn. As a result, some may be biomechanically amenable to nonoperative treatment, while others would be indicated for early reconstruction. Further research into the biological and biomechanical determinants of nonoperative treatment failure will assist with more precise treatment recommendations. Clinical Relevance: Describing the biomechanical consequences of different, clinically significant partial UCL tears potentially allows more precise recommendations for operative and nonoperative treatment.

Posterior olecranon resection and ulnar collateral ligament strain

2004 ◽  
Vol 13 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Jared S Levin ◽  
Nigel Zheng ◽  
Jeffrey Dugas ◽  
E.Lyle Cain ◽  
James R Andrews
Keyword(s):  
Ulnar Collateral Ligament ◽  
Collateral Ligament ◽  
Ligament Strain
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