Environmental drivers of the first major animal extinction across the Ediacaran White Sea-Nama transition.

The Ediacara Biota-the oldest communities of complex, macroscopic fossils-consists of three temporally distinct assemblages: the Avalon (ca. 575-560 Ma), White Sea (ca. 560-550 Ma), and Nama (ca. 550-539 Ma). Generic diversity varies among assemblages, with a notable decline at the transition from White Sea to Nama. Preservation and sampling biases, biotic replacement, and environmental perturbation have been proposed as potential mechanisms for this drop in diversity. Here, we compile a global database of the Ediacara Biota, specifically targeting taphonomic and paleoecological characters, to test these hypotheses. Major ecological shifts in feeding mode, life habit, and tiering level accompany an increase in generic richness between the Avalon and White Sea assemblages. We find that ∼80% of White Sea taxa are absent from the Nama interval, comparable to loss during Phanerozoic mass extinctions. The paleolatitudes, depositional environments, and preservational modes that characterize the White Sea assemblage are well represented in the Nama, indicating that this decline is not the result of sampling bias. Counter to expectations of the biotic replacement model, there are minimal ecological differences between these two assemblages. However, taxa that disappear exhibit a variety of morphological and behavioral characters consistent with an environmentally driven extinction event. The preferential survival of taxa with high surface area relative to volume may suggest that this was related to reduced global oceanic oxygen availability. Thus, our data support a link between Ediacaran biotic turnover and environmental change, similar to other major mass extinctions in the geologic record.

Two- and three-body fragmentation of multiply charged tribromomethane by ultrafast laser pulses.

We investigate the two- and three-body fragmentation of tribromomethane (bromoform, CHBr3) resulting from multiple ionization by 28-femtosecond near-infrared laser pulses with a peak intensity of 6 × 1014 W cm-2. The analysis focuses on channels consisting exclusively of ionic fragments, which are measured by coincidence momentum imaging. The dominant two-body fragmentation channel is found to be Br+ + CHBr2+. Weaker HBr+ + CBr2+, CHBr+ + Br2+, CHBr2+ + Br2+, and Br+ + CHBr22+ channels, some of which require bond rearrangement prior to or during the fragmentation, are also observed. The dominant three-body fragmentation channel is found to be Br+ + Br+ + CHBr+. This channel includes both concerted and sequential fragmentation pathways, which we identify using the native frames analysis method. We compare the measured kinetic energy release and momentum correlations with the results of classical Coulomb explosion simulations and discuss the possible isomerization of CHBr3 to BrCHBr-Br (iso-CHBr3) prior to the fragmentation.

Strong-field induced fragmentation and isomerization of toluene probed by ultrafast femtosecond electron diffraction and mass spectrometry.

We investigate the fragmentation and isomerization of toluene molecules induced by strong-field ionization with a femtosecond near-infrared laser pulse. Momentum-resolved coincidence time-of-flight ion mass spectrometry is used to determine the relative yield of different ionic products and fragmentation channels as a function of laser intensity. Ultrafast electron diffraction is used to capture the structure of the ions formed on a picosecond time scale by comparing the diffraction signal with theoretical predictions. Through the combination of the two measurements and theory, we are able to determine the main fragmentation channels and to distinguish between ions with identical mass but different structures. In addition, our diffraction measurements show that the independent atom model, which is widely used to analyze electron diffraction patterns, is not a good approximation for diffraction from ions. We show that the diffraction data is in very good agreement with ab initio scattering calculations.

Cenozoic Rotation History of Borneo and Sundaland, SE Asia Revealed by Paleomagnetism, Seismic Tomography, and Kinematic Reconstruction.

SE Asia comprises a heterogeneous assemblage of fragments derived from Cathaysia (Eurasia) in the north and Gondwana in the south, separated by suture zones representing closed former ocean basins. The western part of the region comprises Sundaland, which was formed by Late Permian-Triassic amalgamation of continental and arc fragments now found in Indochina, the Thai Penisula, Peninsular Malaysia, and Sumatra. On Borneo, the Kuching Zone formed the eastern margin of Sundaland since the Triassic. To the SE of the Kuching Zone, the Gondwana-derived continental fragments of SW Borneo and East Kalimantan accreted in the Cretaceous. South China-derived fragments accreted to north of the Kuching Zone in the Miocene. Deciphering this complex geodynamic history of SE Asia requires restoration of its deformation history, but quantitative constraints are often sparse. Paleomagnetism may provide such constraints. Previous paleomagnetic studies demonstrated that Sundaland and fragments in Borneo underwent vertical axis rotations since the Cretaceous. We provide new paleomagnetic data from Eocene-Miocene sedimentary rocks in the Kutai Basin, east Borneo, and critically reevaluate the published database, omitting sites that do not pass widely used, up-to-date reliability criteria. We use the resulting database to develop an updated kinematic restoration. We test the regional or local nature of paleomagnetic rotations against fits between the restored orientation of the Sunda Trench and seismic tomography images of the associated slabs. Paleomagnetic data and mantle tomography of the Sunda slab indicate that Sundaland did not experience significant vertical axis rotations since the Late Jurassic. Paleomagnetic data show that Borneo underwent a ~35° counterclockwise rotation constrained to the Late Eocene and an additional ~10° counterclockwise rotation since the Early Miocene. How this rotation was accommodated relative to Sundaland is enigmatic but likely involved distributed extension in the West Java Sea between Borneo and Sumatra. This Late Eocene-Early Oligocene rotation is contemporaneous with and may have been driven by a marked change in motion of Australia relative to Eurasia, from eastward to northward, which also has led to the initiation of subduction along the eastern Sunda trench and the proto-South China Sea to the south and north of Borneo, respectively.

Implications of Core and Hip Injuries on Major League Baseball Pitchers on the Disabled List.

PURPOSE: To investigate the frequency of core and hip injuries in Major League Baseball (MLB) pitchers and their impact on performance, workload, and pitch type. METHODS: Demographic, performance data, and injury data were acquired for 330 MLB pitchers with 454 injuries placed on the disabled list (DL) from 2014 to 2015 seasons. Core and hip/groin injuries were analyzed in which injury year data were compared with career data and against other injury groups. RESULTS: Core injuries represented 14% of all injuries and hip/groin injuries represented 7%. Average days on the DL for core injuries were 47.0 (standard deviation 5.6) days and 37.7 (standard deviation 8.1) days for hip/groin injuries. Return from the DL the same season for core injuries was 78% and 73% for hip/groin injuries. Core injuries returned to the DL 46% of the time (73% for noncore injuries) and hip/groin returned 56% of the time (60% for nonhip/groin injuries). No changes in workload were noted except starters with core injuries pitched less innings/game (5.3 vs 4.9 innings/game, P = .031) and more pitches/game (85.5 vs 78.4 pitches, P = .026). Fastball velocity decreased in the core injury group the year of injury (91.6 vs 92.2 mph, P = .001). Core injuries had slightly fewer home runs/9 innings and fewer strikeouts/9 innings; hip/groin injuries had slightly more strikeouts/9 innings, with all other performance statistics no different between the groups including earned run average and wins above replacement. CONCLUSIONS: Core and hip injuries in MLB pitchers result in similar time on the DL compared with other injuries. Pitching workload during the year of injury does not seem to have a significant impact on sustaining a core or hip injury. Although there is a high rate of return to play from the DL, there is a high rate of reinjury in these pitchers more often for other injuries. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Single-Shot Femoral Nerve Block Does Not Cause Long-Term Strength and Functional Deficits Following Anterior Cruciate Ligament Reconstruction.

PURPOSE: To determine if patients treated with a single-shot femoral nerve block have strength and functional deficits at 9-month follow-up. METHODS: Forty-three patients who underwent primary anterior cruciate ligament reconstructions were randomized to receive either a preoperative single-shot femoral nerve block or local infiltration anesthesia for primary pain control. All patients underwent a standardized comprehensive rehabilitation program postoperatively. Isokinetic strength and function was tested using a Biodex machine at 9 months or more postoperatively comparing the operative and nonoperative extremity. RESULTS: No significant difference in strength was found at an average of 10.6 months postoperatively (range, 9-15 months) between the femoral nerve block and control groups. In comparing strength deficits, we found no difference in slow isokinetic extension strength (22.4% vs 27.8%, P = .51), fast isokinetic extension strength (18.5% vs 12.5%, P = .41), slow isokinetic flexion strength (11.0% vs 15.1%, P = .55), and fast isokinetic flexion strength (8.2% vs 4.9%, P = .56) in the femoral nerve block versus control groups, respectively. In terms of functional outcomes, there also was no difference in deficits for single-leg hop distance (P = .12), timed single-leg hop (P = .74), and single-leg triple hop distance (P = .94). Maximal strength noted to be within 15% of the contralateral limb was achieved in 40% of patients and maximal function in 63% of patients at an average of 10.6 months postoperatively. A 13% complication rate was found in patients who received a femoral nerve block (1 with prolonged quadriceps inhibition and 2 with prolonged sensory disturbances). CONCLUSIONS: Our study found a 13% motor/sensory complication rate in patients who underwent femoral nerve block for pain control after anterior cruciate ligament reconstruction. Although these deficits may persist, they are not permanent and are not different when compared with controls at 9-month follow-up. However, maximal strength and function are not fully restored at normal return to play time and rehabilitation should continue long term to maximize recovery. LEVEL OF EVIDENCE: Level I, prospective randomized trial.

Performance, Return to Play, and Career Longevity After Ulnar Collateral Ligament Reconstruction in Professional Catchers.

PURPOSE: The purpose of our study was to evaluate return to play and postinjury performance of professional catchers who sustained an ulnar collateral ligament (UCL) rupture requiring surgical reconstruction. We looked to evaluate these players to determine the rate of return to play, the level of return to play, and career longevity after surgery as well as how statistical performance is affected by reconstruction. METHODS: Twenty-five professional catchers who underwent UCL reconstruction between 1985 and 2015 were identified and compared with an age-, position-, and competition-matched control group. Priority was placed on level of play, year of injury, age, and years played prior to injury in matching controls. Injury information and demographic data (age at injury, level of play, and career length) were collected from publicly available team websites and press releases. Offensive and defensive performance statistics were collected for 3 years prior to injury and 3 years after return. Return to play, return to level of play, and career after return were also analyzed. RESULTS: The average age at time of UCL injury was 24.4 (standard deviation, 4.5) years old. Return to play for all catchers was 80% (20/25), with only one player not returning to the same previous level of play (95%). Average years in Major League Baseball (MLB) after return was 2.3 years versus 2.6 years in the control group (P = .07), with 4.3 years total (MLB and minors) versus 3.8 years total in the control group (P = .28). There were no changes in offensive or defensive performance before and after injury. CONCLUSIONS: UCL reconstruction in professional catchers can lead to successful outcomes. Catchers can expect a high rate of return to play with high rate of return to previous level of play, similar performance, and no change in career longevity following return from UCL reconstruction. STUDY DESIGN: Level III, case-control series.

Return to play after shoulder instability in National Football League athletes.

HYPOTHESIS: We hypothesized that National Football League (NFL) players sustaining a shoulder destabilizing injury could return to play (RTP) successfully at a high rate regardless of treatment type. METHODS: We identified and evaluated 83 NFL players who sustained an in-season shoulder instability event while playing in the NFL. NFL RTP, incidence of surgery, time to RTP, recurrent instability events, seasons/games played after the injury, and demographic data were collected. Overall RTP was determined, and players who did and did not undergo operative repair were compared. RESULTS: Ninety-two percent of NFL players returned to NFL regular season play at a median of 0.0 weeks in those sustaining a shoulder subluxation and 3.0 weeks in those sustaining a dislocation who did not undergo surgical repair (P = .029). Players who underwent operative repair returned to play at a median of 39.3 weeks. Forty-seven percent of players had a recurrent instability event. For players who were able to RTP, those who underwent surgical repair (31%) had a lower recurrence rate (26% vs. 55%, P = .021) and longer interval between a recurrent instability event after RTP (14.7 vs. 2.5 weeks, P = .050). CONCLUSION: There is a high rate of RTP after shoulder instability events in NFL players. Players who sustain shoulder subluxations RTP faster but are more likely to experience recurrent instability than those with shoulder dislocations. Surgical stabilization of the shoulder after an instability event decreases the chances of a second instability event and affords a player a greater interval between the initial injury and a recurrent event.

Ultrasound evaluation of the ulnar collateral ligament of the elbow: Which method is most reproducible?

INTRODUCTION: The ulnar collateral ligament (UCL) is an important medial stabilizer of the elbow, particularly in overhead-throwing athletes. However, there is no universally accepted method for evaluating UCL thickness with ultrasound (US). OBJECTIVE: To assess reproducibility of previously published methods, as well as a modified technique, for evaluating the UCL via US. We hypothesize that a modified technique would show greater reproducibility. MATERIAL AND METHODS: Using US, the thickness of the UCL in 50 volunteers was measured by two musculoskeletal trained radiologists using two different measurement techniques. The techniques utilized were as described by Nazarian and Jacobson/Ward (JW). Technique measurements were evaluated using interclass correlation coefficients (ICC) to determine the reproducibility of each method. Twenty-eight of the subjects also underwent measurement via a modified JW technique, measured perpendicular to the ligament rather than the frame of imaging. This technique was also evaluated with ICC values. RESULTS: The ICC value for the Nazarian technique was 0.82 (very good) and 0.51 (moderate) for the JW technique. When using the modified JW technique, we found an ICC value of 0.84 (very good). Mean ligament thickness was greatest with the Nazarian technique, 6.41 mm, with the JW technique measuring 1.86 mm and the modified technique measuring 1.38 mm. CONCLUSION: US assessment of UCL thickness by all three measurement techniques are reproducible. The JW technique had less interobserver agreement when compared to the Nazarian method, whereas the modified JW technique had greater reproducibility compared to the JW technique and similar to the Nazarian technique.

Major League pitching workload after primary ulnar collateral ligament reconstruction and risk for revision surgery.

BACKGROUND: Literature has attempted to correlate pitching workload with risk of ulnar collateral ligament (UCL) injury; however, limited data are available in evaluating workload and its relationship with the need for revision reconstruction in Major League Baseball (MLB) pitchers. METHODS: We identified 29 MLB pitchers who underwent primary UCL reconstruction surgery and subsequently required revision reconstruction and compared them with 121 MLB pitchers who underwent primary reconstruction but did not later require revision surgery. Games pitched, pitch counts, and innings pitched were evaluated and compared for the seasons after returning from primary reconstruction and for the last season pitched before undergoing revision surgery. RESULTS: The difference in workload between pitchers who did and did not require revision reconstruction was not statistically significant in games pitched, innings pitched, and MLB-only pitch counts. The one significant difference in workload was in total pitch counts (combined MLB and minor league), with the pitchers who required revision surgery pitching less than those who did not (primary: 1413.6 pitches vs. revision: 959.0 pitches, P = .04). In addition, pitchers who required revision surgery underwent primary reconstruction at an early age (22.9 years vs. 27.3 years, P < .001) and had less MLB experience (1.5 years vs. 5.0 years, P < .001). CONCLUSIONS: There is no specific number of pitches, innings, or games that place a pitcher at an increase risk for injury after primary UCL reconstruction. However, correlations of risk may be younger age and less MLB experience at the time of the primary reconstruction.

Liposomal Bupivacaine Versus Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Trial.

PURPOSE: To compare femoral nerve block (FNB) versus local liposomal bupivacaine (LB) for pain control in patients undergoing anterior cruciate ligament (ACL) reconstruction. METHODS: Eighty-five patients undergoing primary ACL reconstruction were assessed for participation. We performed a prospective randomized trial in accordance with the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The study arms included either intraoperative local infiltration of LB (20 mL of bupivacaine/10 mL of saline solution) or preoperative FNB with a primary outcome of postoperative pain levels (visual analog scale) for 4 days. Secondary outcomes assessed included opioid consumption (intravenous morphine equivalents), hours slept, patient satisfaction, and calls to the physician. Randomization was by a computerized algorithm. The observer was blinded and the patient was not blinded to the intervention. RESULTS: One patient declined participation; 2 patients were excluded after randomization. A total of 82 patients were analyzed. Outcomes showed a significant increase in pain in the LB group between 5 and 8 hours postoperatively (mean ± standard deviation, 6.3 ± 2.0 versus 4.8 ± 2.6; P = .01). There were no significant differences between the groups in mean daily pain levels, morphine equivalents, or patient satisfaction when we controlled for graft type, age, body mass index, and sex. Patients receiving an FNB had a nonsignificant increase in number of sleep disturbances on the day of surgery (mean ± standard deviation, 4.4 ± 3.7 v 3.1 ± 2.1; P = .09) and were more likely to call their doctor the following day because of pain (29% v 8%, P = .04). Six patients in the FNB group had either prolonged quadriceps inhibition or sensory disturbance. One patient in the LB group required reoperation for a flexion contracture. CONCLUSIONS: An increase in acute postoperative pain was found with LB compared with FNB for post-ACL reconstruction pain control. After the acute postoperative period, there were no significant differences in opioid consumption or pain control. The occurrence of nerve irritation postoperatively was found to be higher in the FNB group. LEVEL OF EVIDENCE: Level I, prospective randomized trial.

Major League Baseball pitch velocity and pitch type associated with risk of ulnar collateral ligament injury.

BACKGROUND: The number of Major League Baseball (MLB) pitchers requiring ulnar collateral ligament (UCL) reconstructions is increasing. Recent literature has attempted to correlate specific stresses placed on the throwing arm to risk for UCL injury, with limited results. METHODS: Eighty-three MLB pitchers who underwent primary UCL reconstruction were evaluated. Pitching velocity and percent of pitch type thrown (fastball, curve ball, slider, and change-up) were evaluated 2 years before and after surgery. Data were compared with control pitchers matched for age, position, size, innings pitched, and experience. RESULTS: The evaluation of pitch velocity compared with matched controls found no differences in pre-UCL reconstruction pitch velocities for fastballs (91.5 vs. 91.2 miles per hour [mph], P = .69), curveballs (78.2 vs. 77.9 mph, P = .92), sliders (83.3 vs. 83.5 mph, P = .88), or change-ups (83.9 vs. 83.8 mph, P = .96). When the percentage of pitches thrown was evaluated, UCL reconstructed pitchers pitch significantly more fastballs than controls (46.7% vs. 39.4%, P = .035). This correlated to a 2% increase in risk for UCL injury for every 1% increase in fastballs thrown. Pitching more than 48% fastballs was a significant predictor of UCL injury, because pitchers over this threshold required reconstruction (P = .006). CONCLUSION: MLB pitchers requiring UCL reconstruction do not pitch at higher velocities than matched controls, and pitch velocity does not appear to be a risk factor for UCL reconstruction. However, MLB pitchers who pitch a high percentage of fastballs may be at increased risk for UCL injury because pitching a higher percent of fastballs appears to be a risk factor for UCL reconstruction.

Coronary Vasospasm and Bowel Ischemia in a Patient with Metastatic Gastrointestinal Carcinoid.

We describe a case of a 60-year-old female with a history of metastatic carcinoid disease with liver involvement who developed coronary vasospasm and mesenteric ischemia. The carcinoid syndrome is known for its cardiac involvement most well characterized by fibrous tissue deposits on the endocardium.(1,2) Case reports of coronary artery vasospasm have been previously described and hypothesized to be mediated by vasoactive amines and polypeptides synthesized by the tumor.(3-9) Intestinal ischemia is another reported complication of the carcinoid syndrome and is hypothesized to have a similar mechanism to that of the coronary vasospasm.(10-17) We have reviewed the literature and describe a case of coronary vasospasm and mesenteric ischemia in a patient on octreotide therapy. This is the first case in which we have identified concurrent coronary vasospasm and mesenteric ischemia in a patient with carcinoid disease.

Pre- and Postseason Dynamic Ultrasound Evaluation of the Pitching Elbow.

PURPOSE: To use ultrasound imaging to document changes over time (i.e., preseason v postseason) in the pitching elbow of high school baseball pitchers. METHODS: Twenty-two high school pitchers were prospectively followed. Pitchers were evaluated after a 2-month period of relative arm rest via preseason physical exams, dynamic ultrasound imaging of their throwing elbow, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) assessment. Players were reevaluated within 1 week of their last game. Dynamic ultrasound images were then randomized, blinded to testing time point, and evaluated by 2 fellowship-trained musculoskeletal radiologists. RESULTS: Average pitcher age was 16.9 years. Average pitches thrown was 456.5, maximum velocity 77.7 mph, games pitched 7.3, and days off between starts 6.6. From preseason to postseason, there were significant increases in ulnar collateral ligament (UCL) thickness (P = .02), ulnar nerve cross-sectional area (P = .001), UCL substance heterogeneity (P = .001), and QuickDASH scores (P = .03). In addition, there was a nonsignificant increase in loaded ulnohumeral joint space (P = .10). No pitchers had loose bodies on preseason exam, while 3 demonstrated loose bodies postseason. The increase in UCL thickness was significantly associated with the number of bullpen sessions per week (P = .01). The increase in ulnar nerve cross-sectional area was significantly associated with the number of pitches (P = .04), innings pitched (P = .01), and games pitched (P = .04). CONCLUSIONS: The stresses placed on the elbow during only one season of pitching create adaptive changes to multiple structures about the elbow including UCL heterogeneity and thickening, increased ulnohumeral joint space laxity, and enlarged ulnar nerve cross-sectional area. LEVEL OF EVIDENCE: Level II prospective observational study.

A single, global patient-centered measure from the SF-36 instrument to assess surgical outcomes and quality of life: a pilot study.

BACKGROUND: Many quality of life (QoL) and patient-reported outcomes (PRO) measures have been developed to assess the effects of disease processes and treatments. Although these instruments are valuable, the process is hampered because of their number and lack of interchangeability. METHODS: We identified a cohort of patients across a variety of operations within 3-12 months postoperatively. Patients completed the SF-36, measuring eight domains of QoL (physical functioning, role-physical, role-emotional, bodily pain, vitality, mental health, social functioning, and general health), plus a health transition item: Compared to one year ago, how would you rate your health in general now?. (1) Much better now than one year ago. (2) Somewhat better now than one year ago. (3) About the same as one year ago. (4) Somewhat worse than one year ago. (5) Much worse than one year ago. Additional data included improvement of preoperative symptoms, the occurrence of any postoperative symptoms, and the occurrence of any postoperative complications. RESULTS: Of 217 patients, 28 % were much better, 28 % somewhat better, 27 % unchanged, 13 % somewhat worse, and 3 % much worse. The health transition results were associated with all SF-36 domains, preoperative symptom change (p = 0.03) and persistent or new postoperative symptoms (p = 0.001), but not postoperative complications. Patients with persistent or new symptoms postoperatively had worse scores in the role-emotional (p = 0.01), bodily pain (p = 0.05), social functioning (p = 0.02), and mental health (p = 0.009) domains of the SF-36. CONCLUSIONS: This single, global assessment of health transition may be a promising practical alternative to assess postoperative patient-centered outcomes. Improved patients had better QoL scores, preoperative symptoms elimination, and no operation-related symptoms, but the occurrence of complications did not affect improvement.

A randomized study comparing corticosteroid injection to corticosteroid iontophoresis for lateral epicondylitis.

PURPOSE: We designed a prospective, randomized study to evaluate the effects of iontophoresis delivery of dexamethasone versus corticosteroid injection therapy on patient outcomes. METHODS: We randomized 82 patients to 10 mg dexamethasone via iontophoresis using a self-contained patch with a 24-hour battery; 10 mg dexamethasone injection; or 10 mg triamcinolone injection. All patients received the same hand therapy protocol. Primary outcomes tracked were change in grip strength (flexion vs extension), pain, and function scores on a validated questionnaire. The secondary outcome was return-to-work status. Patients were evaluated at baseline, completion of physical therapy, and 6-month follow-up. RESULTS: The iontophoresis patients had statistically significant improvement in grip strength at the conclusion of hand therapy compared with baseline. They were also more likely to get back to work without restriction. By 6-month follow-up, all groups had equivalent results for all measured outcomes. CONCLUSIONS: Dexamethasone via iontophoresis produced short-term benefits because for this group grip strength and unrestricted return to work were significantly better. This study suggests that this iontophoresis technique for delivery of corticosteroid may be considered a treatment option for patients with lateral epicondylitis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Strong-Field-Induced Coulomb Explosion Imaging of Tribromomethane.

The Coulomb explosion of tribromomethane (bromoform, CHBr3) induced by 28 fs near-infrared laser pulses is investigated by three-dimensional coincidence ion momentum imaging. We focus on the fragmentation into three, four, and five ionic fragments measured in coincidence and present different ways of visualizing the three-dimensional momentum correlations. We show that the experimentally observed momentum correlations for 4- and 5-fold coincidences are well reproduced by classical Coulomb explosion simulations and contain information about the structure of the parent molecule that could be used to differentiate structural isomers formed, for example, in a pump-probe experiment. Our results thus provide a clear path toward visualizing structural dynamics in polyatomic molecules by strong-field-induced Coulomb explosion imaging.

Predictors of Clinical Outcomes After Proximal Hamstring Repair.

BACKGROUND: Proximal hamstring avulsions cause considerable morbidity. Operative repair results in improved pain, function, and patient satisfaction; however, outcomes remain variable. PURPOSE: To evaluate the predictors of clinical outcomes after proximal hamstring repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We retrospectively reviewed proximal hamstring avulsions repaired between January 2014 and June 2017 with at least 1-year follow-up. Independent variables included patient demographics, medical comorbidities, tear characteristics, and repair technique. Primary outcome measures were the Single Assessment Numerical Evaluation (SANE), International Hip Outcome Tool-12 (iHOT-12), and Kerlan-Jobe Orthopaedic Clinic (KJOC) Athletic Hip score. Secondary outcome measures included satisfaction, visual analog scale for pain, Tegner score, and timing of return to sports. RESULTS: Of 102 proximal hamstring repairs, 86 were eligible, 58 were enrolled and analyzed (67%), and patient-reported outcomes were available for 45 (52%), with a mean 29-month follow-up. The mean patient age was 51 years, and 57% were female. Acute tears accounted for 66%; 78% were complete avulsions. Open repair was performed on 90%. Overall satisfaction was 94%, although runners were less satisfied compared with other athletes (P = .029). A majority of patients (88%) returned to sports by 7.6 months, on average, with 72% returning at the same level. Runners returned at 6.3 months, on average, but to the same level 50% of the time and at a decreased number of miles per week compared to nonrunners (15.7 vs 7.8, respectively; P < .001). Postoperatively, 78% had good/excellent SANE Activity scores, but the mean Tegner score decreased (from 5.5 to 5.1). Acute tears had higher SANE Activity scores. The mean iHOT-12 and KJOC scores were 99 and 77, respectively. Endoscopic repairs had equivalent outcome scores to open repairs, although conclusions were limited given the small number of patients in the endoscopic group. Greater satisfaction was noted in patients older than 50 years (P = .024), although they were less likely to return to running (P = .010). CONCLUSION: Overall, patient satisfaction and functionality were high. With the numbers available, we were unable to detect any significant differences in functional outcome scores based on patient age, sex, body mass index, smoking status, medical comorbidities, tear grade, activity level, or open versus endoscopic technique. Acute tears had better SANE Activity scores. Runners should be cautioned that they may be unable to return to the same preinjury activity level after proximal hamstring repair. CLINICAL RELEVANCE: When counseling patients with proximal hamstring tears, runners and those with chronic tears should set appropriate expectations.

Major League Baseball Pitching Performance After Tommy John Surgery and the Effect of Tear Characteristics, Technique, and Graft Type.

BACKGROUND: Return to play and player satisfaction have been quite high after ulnar collateral ligament reconstruction (UCLR); however, there has been little reported on how outcomes are affected by surgical technique, graft type, and tear characteristics. PURPOSE: To evaluate surgical techniques, graft type, and tear characteristics on Major League Baseball (MLB) performance after UCLR. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: MLB pitchers who underwent primary UCLR at a single institution were included. Tear characteristics included tear location, tear grade, and acuity. Surgical technique and graft type were also collected. Pitching performance statistics, including earned run average (ERA), walks and hits per innings pitched (WHIP), innings pitched, and fastball velocity were evaluated 3 years before and after UCLR. RESULTS: Forty-six MLB pitchers were identified as having primary UCLR. Return to play was 96%, with 82% returning to MLB play. Technique performed showed no difference in performance. As compared with pitchers with gracilis grafts, pitchers with palmaris grafts were younger ( P = .043), played longer after surgery ( P = .012), and returned to play at 100% (35 of 35) versus 82% (9 of 11, P = .010). When compared with pitchers with proximal tears, pitchers with distal tears pitched at higher velocity (93.0 vs 90.6 mph, P = .023) and had better performance before surgery (ERA, P = .003; WHIP, P = .021); however, those with proximal tears improved to match this performance and velocity after reconstruction. As compared with those having partial tears, pitchers with complete tears played longer after surgery (5.9 vs 4.0 years, P = .033), had a better ERA before injury ( P = .041), and had better WHIP ( P = .037) and strikeouts per 9 innings ( P = .025) after reconstruction. Pitchers with chronic tears had a significant improvement in postoperative ERA, from 4.49 to 3.80 ( P = .040). CONCLUSION: Technique performed and graft type used did not affect performance; however, pitchers with palmaris grafts returned at a higher rate than those with gracilis grafts. Distal tears occurred in pitchers with greater velocity and better performance before injury, yet pitchers with proximal tears matched this performance after reconstruction. Pitchers with complete tears played longer after reconstruction. Pitchers who had partial tears had worse performance before injury and after reconstruction, and those with chronic tears saw a significant improvement in ERA with reconstruction.