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 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.

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.

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.

Medial Elbow Pain During the Return-to-Throwing Period After Ulnar Collateral Ligament Reconstruction in Pitchers.

BACKGROUND: Ulnar collateral ligament reconstruction (UCLR) is common in the sport of baseball, particularly among pitchers. Postoperative return-to-sport protocols have many players beginning to throw at 4 to 5 months and returning to full competition between 12 and 16 months after surgery. Medial elbow pain during the return-to-throwing period often occurs and can be difficult to manage. PURPOSE: To evaluate the incidence of medial elbow pain and associations with outcomes and revision surgery during the return-to-throwing period after UCLR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Between the years of 2002 and 2014, all pitchers who underwent UCLR at a single institution were identified. Charts were reviewed for incidence of medial elbow pain during return to throwing, return to sport, and subsequent operative interventions, including revision ulnar collateral ligament surgery. RESULTS: Of a total of 616 pitchers who underwent UCLR during the study period, 317 were included in this study. Medial elbow pain was experienced by 45.1% (143 of 317), with a mean time of complaint of 9.75 months after surgery. The groups with and without pain did not differ statistically with regard to age (pain, 20.6 years; no pain, 20.9 years) or level of competition. Of those who experienced medial elbow pain, 10.5% did not return to sport; 5.6% underwent revision UCLR; and 19.6% underwent other operative procedures at the elbow. Among those who did not experience medial elbow pain when returning to throw, 8.7% did not return to sport, with only 1.7% undergoing revision UCLR and 6.9% undergoing other operative elbow procedures. CONCLUSION: Of the pitchers evaluated in the study, approximately half reported pain during the return-to-throwing phase after UCLR. Those who experienced medial elbow pain had a higher rate of subsequent surgical intervention.

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.

Pitching Performance After Ulnar Collateral Ligament Reconstruction at a Single Institution in Major League Baseball Pitchers.

BACKGROUND: Ulnar collateral ligament (UCL) reconstruction (UCLR) has shown reliable rates of return to play, with conflicting results on pitching performance after players' return. PURPOSE: To evaluate Major League Baseball (MLB) pitching performance before and after UCLR performed at a single institution. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: MLB pitchers (minor league players were excluded) who underwent UCLR at our institution between 2002 and 2016 were identified. Player information and return to play were determined including pitching level (MLB vs minor league) and total number of years played after surgery. Pitching performance statistics were evaluated for 3 years before surgery and for 3 years after returning to play including earned run average (ERA), walks plus hits per inning pitched (WHIP), innings pitched, wins above replacement, runs above replacement, and pitch velocity. RESULTS: A total of 54 MLB pitchers were identified, with 46 primary and 8 revision reconstructions. The mean time to return to play was 13.8 months (primary reconstruction: 13.7 months). The majority returned to play with a 94% return rate (primary reconstruction: 96%), and 80% returned to MLB play (primary reconstruction: 82%). Three primary reconstructions required revision surgery. Pitchers played a mean of 3.2 years in MLB and 4.6 years total after surgery (39% still playing). Pitching workload and performance were maintained or improved after surgery. The preoperative ERA was 4.63 versus 4.13 after returning to play ( P = .268). Fastball velocity ( P = .032), ERA ( P = .003), and WHIP ( P = .001) worsened the first year after surgery and then improved the second year (ERA: 4.63 to 4.06 [ P = .380]; WHIP: 1.35 to 1.32 [ P = .221]; fastball velocity: 91.3 to 91.9 mph [ P = .097]). Compared with a matched control group, pitchers who had UCLR showed improvements or maintained performance after reconstruction including improved ERA ( P = .007), WHIP ( P = .025), and fastball velocity ( P = .006). CONCLUSION: MLB players experienced a high rate of return to play and previous level of play after UCLR. Pitching workload was maintained after returning to play. Pitching performance initially decreased the first year after returning and then improved or reverted to previous levels after the first year from UCLR.

Infection and Rerupture After Surgical Repair of Achilles Tendons.

BACKGROUND: Surgical repair of an Achilles tendon rupture has been shown to decrease rerupture rates. However, surgery also increases the risk of complications, including infection. PURPOSE: To determine the risk factors for infection and rerupture after primary repair of Achilles tendon ruptures. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective review was performed on 423 patients who underwent operative treatment of Achilles tendon ruptures between the years 2008 and 2014. The primary outcome of interest was the total rate of infection, and the secondary outcome of interest was the incidence of rerupture within 2 years of operation. RESULTS: A total of 423 patients were analyzed, with a mean age of 46 years (range, 16-83 years) and a mean body mass index of 31.4 kg/m2 (range, 17-55 kg/m2). The overall infection rate was 2.8%, and the rerupture rate was 1%. The median time between surgery and superficial surgical site infection was 30 days, and the median time between surgery and rerupture was 38 days. Longer tourniquet times (100.3 ± 34.7 minutes vs 69.9 ± 21.4 minutes; P = .04) and greater estimated blood loss (15.0 ± 9.1 mL vs 5.1 ± 12.0 mL; P = .01) were associated with an increased rate of deep surgical site infections. Patients who had longer operation and tourniquet times trended toward higher rerupture rates (P = .06 and .08, respectively). When compared with nonsmokers, current and previous smokers had an increased incidence of superficial or deep surgical site infections (6.25% vs 1.42%; P = .02). Age, sex, race, body mass index, alcohol use, diabetes, past steroid injections, and mechanism of injury did not contribute to complication rates. CONCLUSION: Achilles tendon repairs were associated with a low risk of infection and rerupture. Patients with longer tourniquet times, higher estimated blood loss, and a history of smoking were at increased risk for surgical site infections. Patients with longer operative times had increased rates of rerupture.

The Effect of Intraoperative Hypothermia on Shoulder Arthroplasty.

Limited evidence is available regarding the correlation between intraoperative hypothermia and perioperative complications in shoulder arthroplasty. The purpose of this study was to determine the incidence of intraoperative hypothermia in patients treated with shoulder arthroplasty and its effect on perioperative complications. A retrospective chart review was performed on 657 consecutive patients who underwent shoulder arthroplasty at a single institution between August 2013 and June 2016. Demographic data, surgery-specific data, postoperative complications, length of stay, and 30-day read-mission were recorded. Patients were classified as hypothermic if their mean intraoperative temperature was less than 36°C. Statistical analyses with univariate and multivariate logistic regression were performed to evaluate the association of intraoperative hypothermia with perioperative complications. The incidence of intraoperative hypothermia in shoulder arthroplasty was 52.7%. Increasing age (P=.002), lower body mass index (P=.006), interscalene anesthetic (P=.004), and lower white blood cell count (P<.001) demonstrated increased association with hypothermia. Longer operating room times and increased estimated blood loss were not found to be associated with intraoperative hypothermia. Hypothermia demonstrated no significant association with surgical site infections nor any other perioperative complications. Patients undergoing shoulder arthroplasty showed a high incidence of intraoperative hypothermia. Lower body mass index, increasing age, interscalene anesthetic, and lower white blood cell count were associated with an increased incidence of hypothermia. Contrary to previous studies, intraoperative hypothermia was not found to contribute to perioperative complications in shoulder arthroplasty. [Orthopedics. 2018; 41(4):e523-e528.].

Epidemiology, Workload, and Performance of Major League Baseball Pitchers Placed on the Disabled List.

There is limited information on the effect of pitcher workload, pitch type, and performance of Major League Baseball pitchers placed on the disabled list (DL). This study evaluated demographic, performance, workload, and injury data of 330 Major League Baseball pitchers with 454 injuries who were placed on the DL during the 2014 and 2015 seasons. Upper extremity, lower extremity, core, hip/groin, and other injuries were analyzed, and injury year data were compared with career data as well as against other injury groups. Upper extremity injuries represented 60% of injuries and a mean of 61.4 (SE, 2.6) days on the DL, while lower extremity and core injuries each represented 14% of all injuries. Players with upper extremity injuries returned to play the same season at the lowest rate (67.3%). Starters pitched more mean innings per game (5.31 vs 5.14 innings, P=.012) and threw more mean pitches per game (85.9 vs 82.4 pitches, P=.003) the year of injury compared with their career. There was a decrease in mean fastball velocity (92.2 vs 91.6 mph, P<.001) and percentage of fastballs thrown (60.3% vs 58.5%, P<.001) the year of injury for all injuries. The authors found that upper extremity injuries are the most common, require the most time on the DL, and have the lowest same season return to play rate. Starters pitched significantly more innings and threw more pitches during the year of injury. Pitchers were found to have a decrease in fastball velocity and percentage of fastballs thrown during the year of injury. [Orthopedics. 2018; 41(3):178-183.].

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.

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.

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.

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.

Return to Play After Revision Anterior Cruciate Ligament Reconstruction in National Football League Players.

BACKGROUND: National Football League (NFL) players who undergo anterior cruciate ligament (ACL) reconstruction have been shown to have a lower return to play (RTP) than previously expected. However, RTP in the NFL after revision ACL reconstruction (RACLR) is not well defined. PURPOSE/HYPOTHESIS: The purpose of this study is to determine the RTP of NFL players after RACLR and evaluate factors that predict RTP. Our hypothesis was that more experienced and established players would be more likely to RTP after RACLR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 24 NFL players who underwent RACLR between 2007 and 2014 were reviewed and evaluated. Return to NFL play, time to return, seasons and games played prior to and after revision surgery, draft status, and demographic data were collected. Overall RTP was determined, and players who did RTP were compared with those unable to RTP. Data were also compared with control players matched for age, position, size, and experience. RESULTS: After RACLR, 79% (19/24) of NFL players returned to NFL regular-season play at an average of 12.6 months. All players who were drafted in the first 4 rounds, played in at least 55 games, or played 4 seasons of NFL play prior to injury were able to RTP. Players drafted in the first 4 rounds of the NFL draft were more likely to RTP than those who were not (odds ratio, 0.1; 95% CI, 0.01-1.00; P = .05). Those who returned to NFL play played in significantly less games and seasons after their injury than before (P = .01 and P = .01, respectively). However, these values did not differ when compared with matched controls (P = .67 and P = .33). CONCLUSION: NFL players who RTP after RACLR do so at a similar rate but prolonged time period compared with after primary ACL reconstruction. Athletes who were drafted in earlier rounds were more likely to RTP than those who were not. Additionally, player experience prior to injury is an important factor when predicting RTP after RACLR.

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.