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Parameters such as the leaf area index (LAI), canopy chlorophyll content (CCH), and canopy carotenoid content (CCA) are important indicators for evaluating the ecological functions of forests. Currently, rapidly developing unmanned aerial vehicles (UAV) equipped with hyperspectral technology provide advanced technical means for the real-time dynamic acquisition of regional vegetation canopy parameters. In this study, a hyperspectral sensor mounted on a UAV was used to acquire the data in the study area, and the canopy parameter estimation model of moso bamboo forests (MBF) was developed by combining the PROSAIL radiative transfer model and the machine learning regression algorithm (MLRA), inverted the canopy parameters such as LAI, CCH, and CCA. The method first utilized the extended Fourier amplitude sensitivity test (EFAST) method to optimize the global sensitivity analysis and parameters of the PROSAIL model, and the successive projections algorithm (SPA) was used to screen the characteristic wavebands for the inversion of MBF canopy parameter inversion. Then, the optimized PROSAIL model was used to construct the 'LAI-CCH-CCA-canopy reflectance' simulation dataset for the MBF; multilayer perceptron regressor (MLPR), extra tree regressor (ETR), and extreme gradient boosting regressor (XGBR) employed used to construct PROSAIL_MLPR, PROSAIL_ETR, and PROSAIL_XGBR, respectively, as the three hybrid models. Finally, the best hybrid model was selected and used to invert the spatial distribution of the MBF canopy parameters. The following results were obtained: Waveband sensitivity analysis reveals 400–490 and 710–1000 nm as critical for LAI, 540–650 nm for chlorophyll, and 490–540 nm for carotenoids. SPA narrows down the feature bands to 43 for LAI, 19 for CCH, and 9 for CCA. The three constructed hybrid models were able to achieve high-precision inversion of the three parameters of the MBF, the model fitting accuracy of PROSAIL_MLRA reached more than 95%, with lower RMSE values, and the PROSAIL_XGBR model yielded the best fitting results. Our study provides a novel method for the inversion of forest canopy parameters based on UAV hyperspectral data. [ABSTRACT FROM AUTHOR]

Soil heat flux (G) not only affects the Earth's surface energy balance but also models of calculating soil evaporation. A better understanding on the effect of timing, soil and vegetation on riparian G helps to improve energy balance closure and G simulation in riparian areas with various woodlands. This paper examined diurnal and seasonal variation patterns of soil heat flux in urban riparian areas, together with its relationship with net radiation (Rn) including midday G/Rn and the hysteresis phenomenon under the mutual influence of the timing, soil wetness and vegetation conditions. Study sites lie in the riparian areas of Shanghai with seven vegetation-covered conditions—grassland (CH), broadleaf evergreen woodlands with shrubs (CCO), broadleaf evergreen woodlands (CCH), broadleaf deciduous woodlands with shrubs (CUO), broadleaf deciduous woodlands (CUH), conifer with shrubs (CMO) and conifer (CMH). Hourly data of Rn and G on typical days in four seasons starting from 11/2020 to 10/2021 were obtained with automated data-logging sensors. Diurnal variations in soil heat flux were characterized as two patterns depending on leaf area index (LAI)—unimodal curves followed cycles of Rn in woodlands with low LAI (CCH, CCO, CH and CUO) and sinusoidal ones in woodlands with high LAI (CMO, CMH and CUH). Midday G/Rn was generally no more than 10% with slight variations in most woodlands across the four seasons, but upward trends in the grass and CUO were observed in the afternoon. They were found significantly correlated with SWC. For sparse-canopied riparian sites, hourly G was found to be significantly correlated with Rn and SWC in summer, whereas, for dense sites, the role of canopy characteristics overwhelmed soil properties. Equations were derived to estimate diurnal G from Rn, SWC and LAI. The G of all riparian sites was subject to hysteresis problems to Rn. Phase shifts ranged from one to eight hours in riparian sites and were positively related with LAI and SWC, mainly accounting for the second diurnal pattern of G. [ABSTRACT FROM AUTHOR]

Background: Achieving preinjury levels of athletic performance has been challenging for elite athletes after anterior cruciate ligament (ACL) reconstruction. Although a recent study found that 77% of Australian Football League (AFL) players who underwent ACL reconstruction from 1999 to 2013 returned to play at the highest level, the study did not indicate how consistently or well they were able to play., Purpose: To identify the number of AFL players who returned to play consistently over 2 seasons after ACL reconstruction, compare their playing performance in these seasons with preinjury performance, and evaluate factors associated with returning to preinjury levels of performance., Study Design: Case series; Level of evidence, 4., Methods: Analysis included 104 AFL players who underwent ACL reconstruction between 1999 and 2013. All had played at least 10 AFL matches in 1 season before ACL injury. Ranking points, as devised by AFL statisticians, were used to measure individual playing performance., Results: Of the 104 players who played at least 10 matches in 1 season before ACL injury, 53 (51%) returned to play at least 10 matches in 2 seasons after surgery. Of these 53 players, 36 (68%) returned to their preinjury levels of performance. The 17 remaining players who did not return to their preinjury performance still performed comparably to the AFL average level after surgery. Players <25 years old (odds ratio = 2.9, P = .01) or <90 kg (odds ratio = 2.7, P = .03) had greater odds of returning to their preinjury levels of performance., Conclusion: Returning to play on a consistent basis was a substantial challenge for AFL players after ACL reconstruction. However, among players who did return to play consistently over 2 seasons, their postsurgery average performance was comparable with the AFL average level of performance, and two-thirds returned to their preinjury levels of performance. Younger and lighter players were more likely to return to their preinjury levels of performance, possibly given the nature of AFL club playing list management decisions.

Background: Anterior cruciate ligament (ACL) injury has been a major cause of missed game time among Australian Football League (AFL) players. Return to play after ACL reconstruction is not always achieved, even among elite athletes. The rate of subsequent ACL injury in the AFL from 1990 to 2000 was high as compared with that of other elite sports., Purpose: To determine the rates of return to play and subsequent ACL injury after ACL reconstruction among AFL players from 1999 to 2013 and to explore factors associated with differing rates of return to play and subsequent ACL injury., Study Design: Case series; Level of evidence, 4., Methods: A total of 158 AFL players who underwent ACL reconstruction were identified from a prospectively maintained registry of AFL player injuries. Further data were gathered from official playing statistics, surgical records, and structured phone interviews., Results: The rate of return to play after an initial ACL injury was 77% (121 of 158 players). Greater preinjury playing experience and earlier selection in the AFL draft were associated with higher rates of return to play. The rate of subsequent ACL injury to either knee was 30% (48 of 158 players) and was especially high among players aged <21 years (23 of 46 players, 50%). After subsequent ACL injury, 34 of 48 players (71%) returned to play. In primary ACL reconstruction, the use of Ligament Augmentation and Reconstruction System grafts resulted in a faster return to play ( P = .001) but had a higher risk of subsequent revision reconstruction (risk ratio = 2.8, P = .048). Family history of ACL injury was associated with an increased risk of subsequent contralateral ACL injury (risk ratio = 3.8, P = .002)., Conclusion: Most AFL players who underwent ACL reconstruction returned to play at least 1 AFL match. The high rate of subsequent ACL injury among AFL players demonstrates the highly demanding nature of Australian football, particularly at the elite level. The risk factors for subsequent ACL injury should be considered carefully when treatment and rehabilitation decisions are made for these high-demand athletes.

Objectives: The primary objective was to calculate the rate of return to sport (RTS) following anterior cruciate ligament (ACL) reconstruction in elite athletes. Secondary objectives were to estimate the time taken to RTS, calculate rates of ACL graft rupture, evaluate postsurgical athletic performance and identify determinants of RTS., Design: Pooled RTS and graft rupture rates were calculated using random effects proportion meta-analysis. Time to RTS, performance data and determinants of RTS were synthesised descriptively., Data Sources: MEDLINE, EMBASE, AMED, CINAHL, AMI, PEDro, SPORTDiscus and The Cochrane Library were searched from inception to 19 January 2016. Hand searching of 10 sports medicine journals and reference checking were also performed., Eligibility Criteria for Selecting Studies: Studies were included if they reported the ratio of elite athletes who returned to their preinjury level of sport following ACL reconstruction. Twenty-four studies were included., Results: The pooled RTS rate was 83% (95% CI 77% to 88%). The mean time to RTS ranged from 6 to 13 months. The pooled graft rupture rate was 5.2% (95% CI 2.8% to 8.3%). Six out of nine studies that included a noninjured control group found no significant deterioration in athletic performance following ACL reconstruction. Indicators of greater athletic skill or value to the team were associated with RTS., Summary and Conclusions: Eighty-three per cent of elite athletes returned to sport following ACL reconstruction, while 5.2% sustained a graft rupture. Most athletes who returned to sport performed comparably with matched, uninjured controls. This information may assist in guiding expectations of athletes and clinicians following ACL reconstruction., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Parameters such as the leaf area index (LAI), canopy chlorophyll content (CCH), and canopy carotenoid content (CCA) are important indicators for evaluating the ecological functions of forests. Currently, rapidly developing unmanned aerial vehicles (UAV) equipped with hyperspectral technology provide advanced technical means for the real-time dynamic acquisition of regional vegetation canopy parameters. In this study, a hyperspectral sensor mounted on a UAV was used to acquire the data in the study area, and the canopy parameter estimation model of moso bamboo forests (MBF) was developed by combining the PROSAIL radiative transfer model and the machine learning regression algorithm (MLRA), inverted the canopy parameters such as LAI, CCH, and CCA. The method first utilized the extended Fourier amplitude sensitivity test (EFAST) method to optimize the global sensitivity analysis and parameters of the PROSAIL model, and the successive projections algorithm (SPA) was used to screen the characteristic wavebands for the inversion of MBF canopy parameter inversion. Then, the optimized PROSAIL model was used to construct the ‘LAI-CCH-CCA-canopy reflectance’ simulation dataset for the MBF; multilayer perceptron regressor (MLPR), extra tree regressor (ETR), and extreme gradient boosting regressor (XGBR) employed used to construct PROSAIL_MLPR, PROSAIL_ETR, and PROSAIL_XGBR, respectively, as the three hybrid models. Finally, the best hybrid model was selected and used to invert the spatial distribution of the MBF canopy parameters. The following results were obtained: Waveband sensitivity analysis reveals 400–490 and 710–1000 nm as critical for LAI, 540–650 nm for chlorophyll, and 490–540 nm for carotenoids. SPA narrows down the feature bands to 43 for LAI, 19 for CCH, and 9 for CCA. The three constructed hybrid models were able to achieve high-precision inversion of the three parameters of the MBF, the model fitting accuracy of PROSAIL_MLRA reached more than 95%, with lower RMSE values, and the PROSAIL_XGBR model yielded the best fitting results. Our study provides a novel method for the inversion of forest canopy parameters based on UAV hyperspectral data.

Purpose: To demonstrate return to play (RTP) rates, the level of RTP and time taken to RTP in different sports after anterior cruciate ligament reconstruction (ACL-R) and compare the differences between football and rugby. The secondary aims were to compare the differences in intra articular injuries and their treatments and reoperation rates between these sports., Methods: A retrospective review of a consecutive series of all primary ACL-R undertaken by the senior author between 2005 and 2019 was undertaken. Patients were included if they were elite athletes and were a minimum of 2 year post-primary autograft ACL-R. The outcomes measured were RTP (defined as participation in a professional match or in national/international-level competition in amateur sports), time to RTP after surgery and RTP level (Tegner score)., Results: Three hundred and ninety-four elite athletes, with 420 ACL-Rs were included. 235 (55.9%) were in footballers and 125 (29.8%) were in rugby players. 399 (95.0%) of all elite athletes returned to competition at an average of 10.3 months after ACL-R. 386 (90.2% played at the same or higher level post-surgery. Although there was no difference in RTP rates between different sports, rugby players RTP significantly faster than footballers (9.6 vs 10.6 months, (p = 0.027). Footballers were more likely to rupture their ACL during jumping/landing manoeuvres and to receive a PT graft than rugby players. There were no other significant differences between football and rugby players regarding patient characteristics, intraoperative findings, re-rupture and re-operation rates., Conclusions: Over 95% of all elite athletes RTP after primary ACL-R with 90% able to play at the same level. Rugby players RTP significantly faster than footballers., Level of Evience: Level IV., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: After anterior cruciate ligament reconstruction (ACL-R), knee muscle strength symmetry is used as part of the return-to-sport criteria. However, little is known about the changes in the force–velocity (F–V) relationship, which could affect athletic performance. This study investigated the F–V relationship of knee muscles at 4 and 8 months after ACL-R, using the 2-point method tested by isokinetic dynamometry. Methods: A total of 103 physically trained individuals (24.6 [9.3] y, 59.2% male) who underwent primary ACL-R were included. Demographic information and surgery characteristics were collected at 6 weeks postoperatively. Isokinetic knee flexors' and extensors' peak torques were measured at 60° and 240° per second in the concentric mode at 4 and 8 months postoperative. Peak torques and angular velocities were converted to force and linear velocity for calculating maximum isometric force (F0) and the slope of the regression line (F–V slope). Results: At 4 and 8 months postoperative, F0 was significantly lower and F–V slope was significantly less steep (less negative) on the operated leg compared with the nonoperated leg for knee extensors (P <.001) and flexors (P <.001–.002). The limb symmetry index calculated using F0 was lower than the limb symmetry indexes assessed at 60° and 240° per second, especially for knee flexors (P <.001). The use of patellar tendon grafts was associated with lower F0 and a less steep F–V slope compared with hamstring tendon grafts (P <.010). Conclusion: The isokinetic 2-point model assessing the F–V relationship provides additional and relevant insight for evaluating knee muscle strength after ACL-R. [ABSTRACT FROM AUTHOR]

Background: Structured rehabilitation optimizes outcomes and reduces reinjury risk after anterior cruciate ligament reconstruction (ACLR). The coronavirus 2019 (COVID-19) pandemic interrupted standard rehabilitation, possibly affecting ACLR outcomes. Purpose: To characterize changes to ACLR functional outcomes related to the COVID-19 pandemic. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent ACLR between June 11, 2019, and March 11, 2020, (postpandemic group) were compared retrospectively with those who underwent ACLR the year before (June 11, 2018, to March 11, 2019). A mixed-effects linear regression model was used to estimate group differences in isokinetic quadriceps testing. A Kaplan-Meier analysis assessed the probability of achieving >90% limb symmetry index (LSI) for isokinetic quadriceps strength at 60 deg/s and passing all return-to-sport functional outcomes at 1 year postoperatively. Results: A total of 176 patients (80 in the control group and 96 in the postpandemic group) were included. The rate of achieving >90% LSI in isokinetic strength at 60 deg/s at 1 year postoperatively was 39% (95% CI, 27%-49%) for the control group versus 22% (95% CI, 13%-30%) for the postpandemic group (P =.01). Similarly, the rate of achieving >90% LSI in all functional tests at 1 year postoperatively was 15% (95% CI, 7%-22%) for the control group versus 7% (95% CI, 2%-12%) for the postpandemic group (P =.04). The number of in-person physical therapy visits per patient was 25.8 ± 6.8 in the control group versus 24.4 ± 7.5 in the postpandemic group (P =.23). Only the postpandemic group accessed physical therapy using remote telemedicine. Each additional telehealth rehabilitation visit was associated with a 1-week delay in achieving >90% LSI in isokinetic quadriceps strength for the postpandemic group. Conclusion: The COVID-19 pandemic was associated with a decrease in lower extremity strength and a lower probability of achieving limb symmetry and passing the criteria for return to sport at 1 year postoperatively. These results were not due to lack of access to physical therapy. [ABSTRACT FROM AUTHOR]

Background: The extensor apparatus of the knee is of paramount importance in generating the torque needed for a countermovement jump (CMJ), especially in jumping athletes. In anterior cruciate ligament reconstruction (ACLR) procedures, graft harvesting from the extensor apparatus may dramatically affect extensor strength and jumping performance. Hypothesis: The focused jump training of professional jumping athletes would increase the likelihood of restoring jumping performance after ACLR, despite the graft choice (autologous bone-patellar tendon-bone [BPTB] or hamstring [HS] tendon). Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective evaluation of prospectively collected data was carried out. Only professional athletes were included, and all surgical procedures were performed by a single experienced surgeon. Data collection considered the type of surgery, sports activity, and functional evaluation at 3 months after surgery. From the functional evaluation, data on single-leg hop (SLH) test, triple hop (TH) test, and CMJ were extracted. Limb symmetry index (LSI) for maximal voluntary isometric contraction of the quadriceps and for each of the jumping tests was calculated. Multiple analysis of covariance (ANCOVA) models were used to assess mean differences among groups for the LSI in CMJ, SLH, and TH and estimate the effect of confounders. Results: From a subsequent series of 208 athletes, 44 professional athletes were included for data collection. Of these, 26 were male and 18 were female. A jumping sport (basketball, volleyball) was played by 17 athletes, while a running sport (soccer, judo, rugby, tennis, ski) was performed by 27 athletes. The mean time from injury to surgery was 17.8 ± 14.5 days. At 90 days from surgery, the overall mean LSI for CMJ was 85.3% ± 8.9%, for SLH was 92.2% ± 6.4%, and for TH was 90.8% ± 6.1%. When ANCOVA was fitted using the interaction term with BPTB autograft and jumping sport, a nonsignificant effect on LSI for CMJ (P =.56), SLH (P =.72), and TH (P =.98) was observed. Conclusion: The results of the present investigation on professional athletes showed that no difference occurred within the study cohort in overall jumping performance between jumping and running athletes undergoing ACLR either with BPTB or with HS tendon grafts. Although some evidence suggests that quadriceps strength may be dramatically affected by the harvesting of BPTB, the overall performance of the jump was not compromised. [ABSTRACT FROM AUTHOR]

* OBJECTIVE: To estimate anterior cruciate ligament reconstruction (ACLR) return-to-play (RTP) factors and proportions across all National Collegiate Athletics Association (NCAA) sports. * DESIGN: Systematic review with prognosis and etiology components. * LITERATURE SEARCH: Two independent reviewers searched PubMed, Cochrane Library, and Embase databases using terms related to RTP, ACLR, and NCAA for articles published up to June 30, 2023. * STUDY SELECTION CRITERIA: Articles were included if RTP proportions or factors affecting RTP were reported and if the study population included NCAA collegiate athletes recovering from an ACLR. * DATA SYNTHESIS: The proportion represents the total number of athletes who returned to play after ACLR over the total number of ACLR athletes from each cohort. The cumulative proportion represents the aggregated total from each included study. When eligibility information was available (ie, athletes in their final year of eligibility), RTP proportions were ad- justed. The Newcastle-Ottawa Scale (NOS) was used to assess the study quality and scored by 2 raters. * RESULTS: Nine studies were included. RTP criteria varied across the studies. Proportions of RTP ranged from 69% to 92%, with a cumulative RTP proportion after ACLR of 84% (628/745). The primary factors associated with the proportion of RTP were scholarship status, competitive eligibility remaining, depth chart position, and surgical graft type. * CONCLUSIONS: The cumulative proportion of RTP was 84% and was associated with patient-specific and operative factors. Psychological and functional factors were not routinely reported, and rehabilitation protocols were unknown. Data were not explicitly available for any athletes outside of Division I. The criteria for RTP after ACLR varied. [ABSTRACT FROM AUTHOR]

Background: The desire to return to sports (RTS) and return to performance at preinjury level (RTSP) is a common motivator for athletes undergoing anterior cruciate ligament (ACL) reconstructive surgery. However, for non-elite athletes little is known about the patient and surgical variables influencing RTS/RTSP. Purpose was to determine which patient or surgical variables had an effect on RTS/RTSP in non-elite athletes. We also analyzed whether patients that RTS and RTSP have more confidence in the knee and less difficulty pivoting. Methods: A single-centre retrospective cohort study. All patients who had undergone primary hamstring ACL reconstruction within a 5-year period were included. Patients were asked about their pre- and postoperative sports participation using the Tegner Activity Score (TAS) as well as about their RTS/RTSP. Confidence in the knee and difficulty with pivoting were asked about. To determine the potential adverse effect of patient variables at the time of surgery (sex, age, height, weight, TAS preop) and surgical variables (graft diameter, surgical technique, concomitant injury) influencing RTS/RTSP, univariate and multivariate logistic regression analysis were used. Results: 370 ACL reconstructions were included. Average follow-up was 4.6 years (SD 1.4). RTS rate was 65% and RTSP 43%. Median preinjury TAS was 7 (Q1:6, Q3:8)), postoperative 6 (Q1:4, Q3:7). Multivariate analysis showed that women were more likely to RTS (OR 2.40, 1.16–4.97). A lower preinjury TAS (OR 0.80, 0.67–0.95) resulted in higher RTSP levels. None of the surgical variables had a significant influence on RTS or RTSP. Patients who returned to sports or to preinjury-level performance displayed significantly more confidence in the operated knee and less difficulty pivoting than non-returning patients. Conclusion: Our study shows that 65% of non-elite athletes with an ACL reconstruction returned to sports, 43% at preinjury level. Women were over twice more likely to RTS than men. Preinjury TAS significantly influences RTSP, with a lower preinjury TAS leading to a higher percentage of RTSP. Patients returning to both scored better in their self-reported confidence in the knee and difficulty pivoting than non-returning patients. Level of evidence: Retrospective cohort III. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to identify the type of veterinary care sought by handlers of injured agility dogs, the types of treatments the dogs received, and the timeframe for return to training and competition. Procedures: Owners of agility dogs completed an internet-based survey. They were instructed to report injuries that had kept the dog from training or competing for over a week, identify which area(s) of the body had been injured and answer questions about the most severe injury to each body part. Additional questions included if handlers had sought veterinary care, who primarily determined treatment, type of treatment(s), and length of time before the dog could return to full training and competition. Results: This sample included data on 1,714 total injuries from 1,256 unique dogs. Handlers sought veterinary care for over 80% of injuries across all anatomical locations. Handlers were most likely to seek specialty veterinary care for reported injuries to the stifle (71%), iliopsoas (63%) and tibia (61%), and least likely for reported injuries to the carpus (34%), metatarsus (33%) and metacarpus (22%). Treatment of reported injuries to the antebrachium and stifle were most likely to be directed by a veterinarian (>70%), while reported injuries of the thigh (51%) and hip (53%) were least likely. Rest was the most common treatment for all injuries. Return to sport within 3 months was common (>67%) for most perceived injury locations, though dogs with reported stifle injuries took longer to return to competition and had a higher rate of retirement. Conclusion and clinical relevance: Owners of agility dogs have a high rate of seeking veterinary care for injuries. Overall return to sport rates were high, with the stifle being the notable exception. Future studies regarding specific treatment of injuries in agility dogs, and how injuries and their treatment affect return to agility after injury are required to provide optimal care protocols for these canine athletes. [ABSTRACT FROM AUTHOR]

Background: The limb symmetry index (LSI) is a metric of strength restoration. It is key to successfully return to sports after anterior cruciate ligament (ACL) reconstruction. The threshold for return to sports is generally considered an LSI of ≥85%. Purpose: To develop a statistical model for predicting the recovery of knee extension and flexion strength (with LSI ≥85%) at 6 months after ACL reconstruction. Study Design: Case-control study; Level of evidence: 3. Methods: Patients who underwent arthroscopic ACL reconstruction between November 2015 and December 2020 were included. The patients were classified into 2 groups: "pass" if the LSI at 6 months postoperatively was ≥85% and "fail" if the LSI was <85%. Factors in 25 categories with 74 levels, including patient characteristics, periarticular procedures, intra-articular lesions and treatment, and perioperative management, were collected. A multivariable logistic regression combined with backward variable elimination was used to determine the predictive parameters for recovery of knee extension and flexion strength. Results: A total of 948 patients were included. Graft site, preoperative isokinetic strength, treatment of meniscal injury, and injured side (left vs right) were identified as general predictors for both knee extension and flexion strength. For knee extension strength, age at injury and partial weightbearing duration were identified as additional predictors. For knee flexion strength, type of meniscal injury, surgeon volume, cartilage procedures, and periarticular procedures were identified as additional predictors. The Nagelkerke R 2 of the final model was 0.178, and the c -statistic was 0.716 (95% CI, 0.676-0.754). The Hosmer-Lemeshow test indicated good calibration (P =.879). Conclusion: Several factors including preoperative isokinetic strength, treatment of meniscal injuries, left vs. right side and graft site were found to predict recovery of ≥85% LSI in knee extension and flexion strength. Despite the numerous factors that were analyzed, the predictive power was moderate (c-statistic = 0.716), indicating there were other nonincluded factors that significantly influence strength performance at 6 months postoperatively. [ABSTRACT FROM AUTHOR]

Background: The rates of return to play (RTP) after anterior cruciate ligament (ACL) reconstruction among professional and National Collegiate Athletic Association (NCAA) Division I athletes are well described in the orthopaedic literature. Less is known about these rates and risk factors for failure to RTP in Division II and III collegiate athletes. Purpose: To determine the RTP rate after ACL reconstruction among Division II and III collegiate athletes and to explore the factors associated with RTP. Study Design: Case series; Level of evidence, 4. Methods: Demographic and RTP data were retrospectively reviewed for collegiate athletes who underwent ACL reconstructions across high-risk sports over 6 years (2015/16 to 2021/22 seasons) at 5 northeastern NCAA Division II and III institutions. Clinical data collected included Patient Acceptable Symptom State (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation questionnaire, graft type, concomitant reparative surgery, reinjury, need for reoperation, and time to RTP and return to preinjury level. Participants completed the survey using a secure web-based questionnaire sent via email or over the telephone at a minimum 6-month follow-up. Descriptive frequencies were calculated for all documented variables, with chi-square and analysis of variance statistics used to assess for associations and significant differences between variables. Results: A total of 61 eligible student-athletes with primary ACL reconstructions were identified in this study period, and 40 knees were enrolled for analysis with a mean time from surgery to survey completion of 45.0 months. The overall RTP rate was 77.5% (31/40) at a mean of 10.1 months. However, only 50.0% (20/40) returned to their preinjury level of competitive play. There was a graft failure rate of 20% (8/40). Of the 32 athletes who did not reinjure their ACL, 81.25% (26/32) demonstrated a PASS on KOOS Sports and Recreation. Graft rerupture (P <.001) and reoperation (P =.007) had significant effects on rates of RTP. Concomitant procedures (P =.010) influenced return to preinjury level of sports. Injury during the active season versus the off-season significantly influenced KOOS PASS status (P =.038). Conclusion: This study demonstrated that the rate of RTP after ACL reconstruction in this patient population of Division II and III collegiate athletes was 77.5%, with only 50% returning to their preinjury level of competitive play. The graft failure rate in this population was 20%. Surgical factors, such as concomitant surgeries and reinjury of ACL graft, as well as athlete-specific data, such as injury in the off-season, were statistically significant negative influences on patient outcomes. Further research is needed to evaluate other potential factors that may play a role in RTP after ACL reconstruction. [ABSTRACT FROM AUTHOR]

Background: A P value of <.05 is often used to denote statistical significance; however, in many scenarios, this threshold is vulnerable to a small number of outcome reversals. This study joins a body of studies within the orthopaedic literature that evaluate the statistical fragility of existing research via metrics such as fragility index (FI) and fragility quotient (FQ). Purpose/Hypothesis: The purpose of this study was to investigate the statistical fragility of randomized controlled trials (RCTs) and comparative studies on the topic, given the resurgent interest in lateral extra-articular tenodesis (LET) to augment primary or revision anterior cruciate ligament reconstruction (ACLR). It was hypothesized that the outcomes reported in these studies would be statistically fragile. Study Design: Systematic review; Level of evidence, 4. Methods: Comparative studies and RCTs regarding LET as an adjunct procedure to ACLR published between 2000 and 2022 were analyzed. Descriptive characteristics, dichotomous outcomes, and continuous outcomes were extracted. The FI and continuous FI (CFI) were calculated by the number of event reversals to change significance; the FQ and continuous FQ (CFQ) were calculated to normalize the fragility metrics per sample size. Results: Of 455 studies screened, 29 studies were included (9 RCTs, 20 comparative); 79.3% of included studies were published after 2020. A total of 48 dichotomous and 265 continuous outcomes were analyzed. The median FI was 9.0 (IQR, 7.0-13.3), with FQ of 0.1 (IQR, 0.04-0.17); the median CFI was 7.8 (IQR, 4.2-19.6), with CFQ of 0.12 (IQR, 0.08-0.19). The FQ and CFQ for studies on LET with revision ACLR were larger (0.117 and 0.113, respectively) than those focused on primary ACLR (0.042 and 0.095, respectively). Conclusion: Studies focused on LET with primary ACLR were more fragile than those on LET with revision, which suggests that further research on the indications for LET with primary ACLR is necessary. Future orthopaedic comparative research should include fragility metrics alongside traditional P values. [ABSTRACT FROM AUTHOR]

Expansion-type anchors have been developed as an alternative to conventional fixation devices, such as screw-type and button-type anchors, for anterior cruciate ligament (ACL) reconstruction. Here, we present novel expansion-type anchors that minimize damage to both bone tissue and the transplanted ligament during surgery, potentially leading to improved postoperative outcomes for patients. The biomechanical performance of two different expansion-type ACL anchors, the 2 expansion directions type anchor (2EDA) and the 4 expansion directions type anchor (4EDA), was evaluated through finite element analysis. The required force for complete retraction, as well as the stress distribution of the device during the retraction and expansion procedures, was precisely evaluated. Subsequently, we assessed displacement distance and the applied maximum force on bone models under conditions of vertical and oblique force application. The results revealed that both 2EDA and 4EDA for ACL reconstruction have clinical potential, providing sufficient fixation ability under a maximum loading force of 500 N. In this study, we confirmed that ACL reconstruction using the modified expansion-type anchors is a promising approach to enhancing artificial ligament fixation and reducing the risk of postoperative complications. Notably, both 2EDA and 4EDA anchors demonstrated clinical potential, while the 2EDA exhibited improved performance in terms of displacement distance, applied stress, and stress distribution within the bone tunnel. [ABSTRACT FROM AUTHOR]

Background: Because of the increased prevalence of revision anterior cruciate ligament (ACL) reconstruction, there has been a desire to understand the role of posterior tibial slope on increased anterior tibial translation and increased ACL graft forces. One potential concern in supratubercle anterior closing wedge proximal tibial osteotomy (ACW-PTO) for decreasing the posterior tibial slope is the risk of altering the patellar height. Purpose: To radiographically assess changes in (1) patellar height, (2) anterior tibial translation, and (3) posterior tibial slope after supratubercle ACW-PTO. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent supratubercle ACW-PTO by a single surgeon between July 2019 and June 2023 were included. Standardized lateral knee weightbearing radiographs to assess patellar height (via the Caton-Deschamps index), anterior tibial translation of the lateral tibial plateau relative to the lateral femoral condyle, and posterior tibial slope were obtained at 4 time points (preoperatively and 1 day, 3 months, and 6 months postoperatively). Paired t test was used to compare differences between preoperative, 1-day, and 3- and 6-month values for patellar height as measured using the Caton-Deschamps index and for posterior tibial slope. Paired t test was also used to compare differences in the preoperative and 6-month postoperative values for anterior tibial translation. Results: In 20 patients after ACW-PTO, the Caton-Deschamps index demonstrated a significant increase in patellar height on postoperative day 1 (P <.001) but no significant differences at 3 (P =.057) and 6 (P =.176) months postoperatively. Anterior tibial translation on standing lateral knee radiographs was significantly decreased by a mean of 8.9 mm from preoperatively to 6 months postoperatively (P <.001). Posterior tibial slope was significantly decreased by a mean of 11.2° from preoperatively to 6 months postoperatively (P <.001). Conclusion: Supratubercle ACW-PTO performed for ACL reconstruction failure in the setting of an increased posterior tibial slope did not induce significant changes in patellar height postoperatively. Furthermore, after ACW-PTO, there was a significant decrease in anterior tibial translation and posterior tibial slope. [ABSTRACT FROM AUTHOR]

* BACKGROUND: Anterior cruciate ligament tear is a serious knee injury with implications for central nervous system (CNS) plasticity. To perform simple knee movements, people with a history of anterior cruciate ligament reconstruction (ACL-R) engage cross-modal brain regions, and when challenged with cognitive-motor dual tasks, physical performance deteriorates. Therefore, people with ACL-R may increase visual-cognitive neural processes for motor control. * CLINICAL QUESTION: What components of CNS plasticity should the rehabilitation practitioner target with interventions, and how can practitioners augment rehabilitation exercises to target injury associated plasticity? * KEY RESULTS: This clinical commentary (1) describes the neurophysiological foundation for visual-cognitive compensation after ACL-R, (2) provides a theoretical rationale for implementing visual-cognitive challenges throughout the return-tosport continuum, and (3) presents a framework for implementing visual-cognitive challenges from the acute phases of rehabilitation. The Visual-Cognitive Control Chaos Continuum (VC-CCC) framework consists of five training difficulties that progress visual-cognitive challenges from high control to high chaos to better represent the demands of sport. * CLINICAL APPLICATION: The VC-CCC framework augments traditional rehabilitation so that each exercise can progress to increase difficulty and promote sensorimotor and visual-cognitive adaptation after ACL-R. [ABSTRACT FROM AUTHOR]

Background: The impact of anatomical factors, such as the lateral tibial slope (LTS), on outcomes following anterior cruciate ligament (ACL) reconstruction is an area of growing interest. This study was led by the observation that patients with a higher LTS may have different recovery trajectories. Hypothesis/Purpose: The purpose of this study was to investigate the correlation between a higher LTS and long term subjective outcomes following single-bundle ACL reconstruction. Study Design: This study was designed as a retrospective cohort study. Methods: The study comprised 138 patients who underwent single-bundle ACL reconstruction. The LTS was measured on preoperative radiographs. Patient-reported outcome measures (PROMs) were collected, which included the Lysholm Knee Score, UCLA Activity Score, IKDC Score, and Tegner Activity Score, over a mean follow-up duration of 137 months. Results: A significant negative correlation was found between LTS and all measured PROMs (p < 0.001). The established cut-off value of LTS distinguishing between "Good" and "Fair" Lysholm scores was 8.35 degrees. Female patients have statistically significant higher LTS and lower PROMs scores than male. Patients with LTS greater than or equal to 8.35 had significantly lower PROMs, indicative of poorer functional and subjective outcomes. Conclusion: Our findings suggest that a higher LTS is associated with inferior subjective outcomes following single-bundle ACL reconstruction in long term. The LTS cut-off value of 8.35 degrees could potentially be used as a reference in preoperative planning and patient counseling. Clinical relevance: Understanding the relationship between LTS and ACL reconstruction outcomes could inform surgical planning and postoperative management. These findings highlight the need to consider anatomical variances, such as LTS, when assessing patient-specific risks and recovery expectations, contributing to the advancement of personalized care in sports medicine. [ABSTRACT FROM AUTHOR]

Background: Blood flow restriction training (BFRT) is a safe and potentially effective adjunctive therapeutic modality for postoperative rehabilitation related to various knee pathologies. However, there is a paucity of literature surrounding BFRT in high-performance athletes after anterior cruciate ligament reconstruction (ACLR). Purpose: To (1) compare the overall time to return to sports (RTS) in a cohort of National Collegiate Athletic Association (NCAA) Division I athletes who underwent a standardized rehabilitation program either with or without BFRT after ACLR and (2) identify a postoperative time interval for which BFRT has the maximum therapeutic benefit. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 55 student-athletes who underwent ACLR between 2000 and 2023 while participating in NCAA Division I sports at a single institution were included in this study. Athletes were allocated to 1 of 2 groups based on whether they participated in a standardized postoperative rehabilitation program augmented with BFRT (BFRT group; n = 22) or completed the standardized protocol alone (non-BFRT group [control]; n = 33). Our primary outcome measure was time to RTS. The secondary outcome measure was handheld dynamometry quadriceps strength testing at various postoperative time points, converted to a limb symmetry index (LSI). Quadriceps strength was not tested between the BFRT and non-BFRT groups because of the limited amount of data on the control group. Results: The mean age at the date of surgery was 18.59 ± 1.10 years for the BFRT group and 19.45 ± 1.30 years for the non-BFRT group (P =.011), and the mean RTS time was 409 ± 134 days from surgery for the BFRT group and 332 ± 100 days for the non-BFRT cohort (P =.047). For the BFRT group, the mean quadriceps strength LSI increased by 0.67% (95% CI, 0.53%-0.81%) for every week of rehabilitation, and there was a significantly positive rate of change in quadriceps strength in weeks 13-16 compared with weeks 9-12 (ΔLSI, 8.22%; P <.001). Conclusion: In elite NCAA Division I athletes, a statistically significant delay was observed in RTS with BFRT compared with standardized physical therapy alone after undergoing ACLR. There also appeared to be an early window during the rehabilitation period where BFRT had a beneficial impact on quadriceps strength. [ABSTRACT FROM AUTHOR]

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Background: Because of the multitude of variables that affect the retirement decisions of professional soccer players, it has proven difficult to isolate the effect of undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) on career longevity. Purpose: To compare the career longevity of professional soccer players after a primary ACLR with that of an uninjured matched control cohort. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review of a consecutive series of primary ACLR was performed between 2008 and 2018 in professional male soccer players from the senior author's practice. Each athlete with ACLR was matched to 3 control athletes who had not undergone ACLR according to age, league, playing position, and preinjury game appearances/minutes played. Player career statistics—including league, game appearances, and game minutes—were compiled for each year until retirement or July 1, 2022. Results: A total of 82 soccer players in the English Premier League or Championship at the time of their primary ACLR were matched to 246 control athletes. The mean career length after ACLR was 6 ± 2.6 years, while that of the matched control athletes was 7.6 ± 2.8 years (P <.001). After primary ACLR, an athlete had a 2 times greater chance of retirement compared with the matched control athlete (hazard ratio, 2.19; P <.001). At 5 years after ACLR, 16% of athletes had retired from professional soccer, while 8.5% of the matched cohort were retired (P =.060). By 10 years, 72% of the ACLR cohort had retired compared with 43% of the matched cohort (P <.001). Forwards were more likely to have shortened careers compared with goalkeepers (P =.021); however, no significant differences were observed between midfielders, defenders, and forwards. Within the ACLR cohort, a contralateral ACL tear during the athlete's career caused a 2.30 times (P =.022) increased chance of retirement compared with athletes with only 1 ACL tear during their career. Mechanism of injury, meniscal pathology, graft rerupture, and chondral lesions did not affect career length. Conclusion: Professional male soccer players who underwent ACLR had decreased career length by approximately 1.6 years compared with a matched player cohort. [ABSTRACT FROM AUTHOR]

Purpose: To determine the rate and time of return to duty following anterior cruciate ligament reconstruction (ACLR) in military members, and to determine whether their outcomes are influenced by patient characteristics or surgical parameters. Methods: We prospectively assessed 280 military members that underwent ACLR. 27 were excluded due to multi-ligamentous injuries or revision surgery, two did not provide informed consent and 62 were lost to follow-up. Patient demographics, pre-injury physical workload, complications and whether/when patients resumed duty and sports were noted, as well as clinical outcomes at a minimum follow-up of one year, including Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee score (IKDC), Lysholm, and Tegner scale. Results: The final cohort of 189 military members (82% men) had mean age of 25.5 ± 3.4 (range,19–38) at ACLR. At 3.3 ± 1.6 years (range, 1.0–6.3), the Tegner score was 6.1 ± 2.0, Lysholm was 87.0 ± 13.7, IKDC was 80.1 ± 15.7, and KOOS was 81.1 ± 14.8. Only 144 patients (76%) resumed duty, at 9.5 ± 5.3 months (range,1–28), and 141 patients (75%) resumed sport, at 10.2 ± 6.2 months (range,1–35). Multivariable analysis revealed that return to duty was less likely in patients with higher BMI (OR,0.89;p = 0.025), but more likely in patients that followed military physiotherapy (OR,2.76;p = 0.017) and with higher pre-injury physical workload (OR,3.93;p = 0.010). Conclusion: At a follow-up of 3.3 ± 1.6 years, 76% returned to duty at 9.5 ± 5.3 months, and 75% returned to their main sport at 10.2 ± 6.2 months. Patients with higher BMI are significantly less likely to resume military duty and sports; those that followed military physiotherapy were most likely to resume duty, while those that had greater pre-injury physical workload were more likely to both resume duty and sport. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To compare the time to return to sport (RTS) between patients who did and did not suffer a second anterior cruciate ligament (ACL) injury after ACL reconstruction. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: Cochrane Library, Embase, Medline, AMED, and PEDro databases were searched in August 2021 and again in November 2022. STUDY SELECTION CRITERIA: Clinical studies reporting time to RTS after ACL reconstruction and second ACL injury were eligible. DATA SYNTHESIS: We pooled continuous data (time [months] and proportions [%]), with random-effects meta-analyses. Pooled estimates were summarized in forest plots. A qualitative data synthesis was also performed. RESULTS: Twenty-one studies were included in the meta-analysis and 33 in the qualitative synthesis. Pooled incidence of second ACL injury was 16.9% (95% confidence interval [CI]: 12.8, 21.6). Patients who suffered a second ACL injury returned to sport significantly earlier (25 days; 95% CI: 9.5, 40.4) than those who did not suffer another injury. There was no difference in time to RTS for professional athletes who suffered a second ACL injury and those who did not. The certainty of evidence was very low. CONCLUSION: There was very low-certainty evidence that patients who suffered a second ACL injury had returned to sport 25 days earlier than patients who did not have another injury. For professional athletes, there was no difference in time to RTS between athletes who suffered a second ACL injury and athletes who did not. [ABSTRACT FROM AUTHOR]

Purpose: Modern ACL reconstruction (ACL-R) techniques have led to improved outcomes in professional footballers. The aim of this study was to identify and assess patient, surgical and post-operative factors that affected rates and time to return to play (RTP) as well as ACL re-rupture rates., Methods: A retrospective review of consecutive ACL-R undertaken in professional footballers between 2005 and 2018., Results: Two-hundred and thirty-two knees in 215 professional footballers (17 bilateral) were included. 205 (88.9%) were male and average age at surgery was 23.3 ± 4.4 years. Two-hundred and twenty-two (96.1%) returned to professional football, with 209 (90.1%) returning to the same or higher Tegner level. Subgroup analysis revealed three factors that independently affected RTP rate: (1) Players under 25 years had a higher rate of RTP (99.3% vs 90.2%. p = 0.001); (2) a subsequent operation prior to RTP decreased RTP rate from 98.2 to 89.7% (p = 0.009).; (3) undergoing meniscal surgery at ACL-R decreased RTP rate (p = 0.002). The mean time to RTP from surgery was 10.5 ± 3.6 months. Factors found to increase RTP time included age under 25 (11.0 vs 9.7 months, p = 0.005), recurrent effusions (11.4 vs 10.2 months, p = 0.035), and medial meniscal repair at ACL-R compared to meniscectomy (12.5 vs 9.6 months, p = 0.022). The surgical technique varied over the study period in relation to graft type, femoral tunnel position and addition of lateral extra-articular tenodesis (LET). Overall, the re-rupture rate was 8.2% at 2 years. Patella tendon autograft in an anteromedial bundle femoral tunnel position with addition of LET has the lowest re-rupture rate (2.0%)., Conclusion: Primary ACL-R in professional footballers yields high rates of RTP (96.1%), with 90.1% at the same level or higher, at a mean 10.5 months. Patients under 25 years not only had a significantly higher RTP rate, but also had a lengthier period of rehabilitation., Level of Evidence: Level IV., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Individuals post-ACL reconstruction (ACLR) are at elevated risk for ACL re-injury. While several studies have examined biomechanical asymmetries post-ACLR during landing, less is known about asymmetries during a sidestep cut. Therefore, the purpose of this study was to compare sagittal and frontal plane biomechanics at the hip and knee during a 45° sidestep cut in post-ACLR participants and healthy controls. Nineteen athletes post-ACLR and nineteen healthy controls performed a bilateral 45° sidestep cut while three-dimensional kinematics and kinetics were measured. Sagittal and frontal plane kinematics and kinetics were examined at the hip and knee during stance phase. A linear mixed model compared biomechanical differences between the limbs of ACLR and healthy control participants (a = 0.05). In the post-ACLR group, peak hip extension, peak knee flexion, sagittal hip and knee excursion, and the peak knee extensor moment were significantly lower in the ACLR surgical limb compared to the non-surgical limb (p < 0.05). The peak knee flexion angle and peak knee extensor moment were also lower in the ACLR surgical limb compared to the matched control limb (p < 0.05). In summary, post-ACLR participants exhibited altered sagittal plane movement in their surgical limb that was not demonstrated in the non-surgical limb or in control participants, which may suggest avoidance, or reduced utilization of the ACLR limb. [ABSTRACT FROM AUTHOR]

Background: Although anterior cruciate ligament (ACL) injury rates have been studied extensively, it is unclear whether levels of functional and psychological readiness for return-to-sport after primary ACL reconstruction (ACLR) differ based on an athlete's primary sport. Hypothesis: Youth athletes in different primary sports will demonstrate differences in short-term functional recovery, as well as patient-reported psychological and functional recovery after primary ACLR. Study Design: Retrospective cohort study of consecutive patients treated for ACL injury in pediatric sports medicine clinics. Level of Evidence: Level 3. Methods: Patients included underwent primary ACLR between December 1, 2015 and December 31, 2019 and reported sports participation at the time of injury. Demographic data, sports participation, surgical data, functional testing scores (Y-Balance Test [YBT]), functional and psychological patient-reported outcome measures (PROMs), and timing of return-to-play clearance were reviewed. YBT scores were the primary metric for clearance. Four groups were studied: soccer, football, basketball, and other. Results: A total of 220 male and 223 female athletes were included; 65.28% of soccer players were female and 100% of football players were male (P < 0.01). At initial postoperative YBT testing (6-9 months), soccer players had higher operative (P < 0.01) and nonoperative (P < 0.01) leg composite scores when compared with basketball players. No significant differences were found between sports in functional or psychological PROMs at presurgical baseline or 6 months postoperatively. When compared with football, soccer players completed functional clearance in a shorter time from surgery (P = 0.02). Multivariate analysis showed level of competition as a significant independent variable for clearance in female athletes. Conclusion: After primary ACLR, athletes, especially female athletes, demonstrated short-term sport-specific differences in YBT scores. Soccer players attained clearance sooner than football players. Level of competition influenced YBT composite scores in all athletes and time to clearance in female athletes. Clinical Relevance: Sport-specific differences in reinjury should be investigated to determine whether changes in return-to-play evaluation should be implemented. [ABSTRACT FROM AUTHOR]

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria). [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury. Purpose: To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis. Results: Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P <.0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P =.0005), but different results were found in male athletes. (RR, 0.81; P =.21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P =.28). Conclusion: The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes. [ABSTRACT FROM AUTHOR]

Background: A number of studies have investigated return to play after anterior cruciate ligament reconstruction (ACLR) in professional soccer players, but it is unclear which factors are associated with a return to the preinjury performance and ability to play over time. Purpose: To identify factors that contribute to a professional soccer player's return to preinjury performance after ACLR, as well as to report their playing performance at 2 and 5 years after ACLR compared with their preinjury performance. Study Design: Case-control study; Level of evidence, 3. Methods: A consecutive cohort of professional soccer players undergoing primary ACLR were analyzed between 2005 and 2019. A minimum 2-year follow-up was required. The effect of patient, surgical, and postoperative factors on performance rates, defined as a combination of league level and playing time, was evaluated with univariate and multivariate logistic regression models. Results: A total of 200 male professional soccer players were included. When combining league level and playing time, 30% of athletes returned to their preinjury performance at 2 years and 22% at 5 years. However, 53% of athletes returned to their preinjury performance for at least 1 season by year 5. At 2 years, a chondral lesion of grade 3 or 4 decreased the odds of return to preinjury performance (odds ratio [OR], 0.37; P =.010). Athletes receiving an ACLR with the addition of a lateral extra-articular tenodesis procedure were 2.42 times more likely to return to preinjury performance at 2 years than athletes with ACLR alone (P =.004). By 5 years after ACLR, athletes aged ≥25 years at the time of reconstruction were 3 times less likely to be performing at their preinjury performance (OR, 0.32; P <.001), and those with a grade ≥3 chondral lesion were >2 times less likely to be performing at their preinjury performance (OR, 0.43; P =.033). Conclusion: The presence of >50% thickness chondral pathology, ACLR without lateral extra-articular tenodesis, and age >25 years at the time of surgery were all significant risk factors of worse performance rates after ACLR. Significant decreases in performance rates were noted at 2 and 5 years postoperatively. [ABSTRACT FROM AUTHOR]

Context: The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players. Objective: To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries. Data Sources: A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases. Study Selection: Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length. Study Design: The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs. Level of Evidence: Level 4. Data Extraction: Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR. Results: The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up. Conclusion: Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports. [ABSTRACT FROM AUTHOR]

Background: Strength and power is often reduced on the involved versus contralateral limb and healthy controls after anterior cruciate ligament (ACL) reconstruction, but no study has compared with preinjury values at the time of return to sport (RTS). Hypothesis: Divergent recovery patterns in strength and power characteristics will be present at RTS relative to preinjury baseline data and healthy matched controls. Study Design: Cohort study. Level of Evidence: Level 3. Methods: Isokinetic strength tests, bilateral and single-leg countermovement jumps (CMJ; SLCMJ) were measured before ACL rupture in 20 professional soccer players. These then had surgical reconstruction (ACL group) and completed follow-up testing before RTS. Healthy controls (uninjured group) were tested at the same time as the ACL group preinjury. Values recorded at RTS of the ACL group were compared with preinjury. We also compared the uninjured and ACL groups at baseline and RTS. Results: Compared with preinjury, ACL normalized quadriceps peak torque of the involved limb (difference = -7%), SLCMJ height (difference = -12.08%), and Reactive Strength Index modified (RSImod) (difference = -5.04%) were reduced after ACL reconstruction. No significant reductions in CMJ height, RSImod, and relative peak power were indicated at RTS in the ACL group when compared with preinjury values, but deficits were present relative to controls. The uninvolved limb improved quadriceps (difference = 9.34%) and hamstring strength (difference = 7.36%) from preinjury to RTS. No significant differences from baseline were shown in SLCMJ height, power, and reactive strength of the uninvolved limb after ACL reconstruction. Conclusion: Strength and power in professional soccer players at RTS after ACL reconstruction were often reduced compared with preinjury values and matched healthy controls. Clinical Relevance: Deficits were more apparent in the SLCMJ, suggesting that dynamic and multijoint unilateral force production is an important component of rehabilitation. Use of the uninvolved limb and normative data to determine recovery may not always be appropriate. [ABSTRACT FROM AUTHOR]

Background: Patellar femoral chondropathy (FPC) is a common problem in patients undergoing anterior cruciate ligament reconstruction (ACL-R) surgery, which, if left untreated, predisposes to arthrosis. Magnetic resonance imaging (MRI) is the non-invasive gold standard for morphological evaluation of cartilage, while in recent years advanced MRI techniques (such as T2 mapping) have been developed to detect early cartilage biochemical changes. This study evaluates the different onset of early PFC between B-TP-B and HT through T2 mapping. Secondly, it aims to assess the presence of any concordance between self-reported questionnaires and qualitative MRI. Materials and methods: 19 patients enrolled were divided into two groups based on the type of intervention: B-PT-B and HT. After a median time of 54 months from surgery, patients were subjected to conventional MRI, T2 mapping, and clinical-functional evaluation through three self-reported questionnaires: Knee Injury and Osteoarthritis index (KOOS); Tegner Lysholm Knee Scoring Scale; International Knee Documentation Committee (IKDC). Results: There is not statistically significant difference in the comparison between the two MRI techniques and the two reconstructive techniques. KOOS and Tegner Lysholm scales showed significant agreement with MRI results on the grading of chondropathy. Conclusions: There are no differences between B-TP-B and HT techniques in the early development of PFC detectable through non-invasive methods. Due to the large reduction in the frequency of physical activity following ACL-R and the finding of mild PFC (grade I and II) in a substantial proportion of patients, after a relatively short period from ACL-R, all patients should undergo conservative treatment. [ABSTRACT FROM AUTHOR]

Background: An increased posterior tibial slope (PTS) is a proven risk factor for both native anterior cruciate ligament (ACL) and ACL graft insufficiency. Anterior closing wedge high tibial osteotomy (ACW-HTO) for PTS correction is a validated procedure in revision ACL reconstruction (ACLR). Purpose/Hypothesis: The aim of this study was to evaluate the effect of combined ACW-HTO and at least a second revision ACLR procedure on knee stability, function, and sports performance in a large series of patients. The hypothesis was that patients would return to impact sports after ACW-HTO combined with a second or third revision ACLR procedure. Study Design: Case series; Level of evidence, 4. Methods: A total of 64 patients who underwent a second (or more) revision ACLR procedure and ACW-HTO between June 1, 2015, and June 1, 2019, and had a PTS >12° were included. The mean age was 29.60 ± 6.31 years, and the mean preoperative PTS was 13.79°± 1.50°. The cases were analyzed at a mean follow-up of 2.96 ± 0.83 years (range, 2-5 years). At the last follow-up, the rate of patients returning to impact sports (based on the University of California, Los Angeles [UCLA], activity scale), ACL graft status (per magnetic resonance imaging), International Knee Documentation Committee (IKDC) scores, Lysholm scores, and laxity measurements using a knee arthrometer were recorded. Results: The total number of patients participating in impact sports and high-impact sports was as follows: 43 and 30, respectively, before the injury; 0 and 0, respectively, preoperatively; and 31 and 12, respectively, postoperatively. At the last follow-up, the UCLA score was ≥8 in 48.44% of the patients, and only 16 patients returned to their preinjury level of activity. At a minimum of 2 years of follow-up, there was clinical improvement in the IKDC score from 37.98 ± 12.48 preoperatively to 69.06 ± 12.30 postoperatively (P <.0001), in the Lysholm score from 51.94 ± 14.03 preoperatively to 74.45 ± 11.44 postoperatively (P <.001), and in the UCLA score. However, this clinical improvement did not equate to preinjury values for all outcome scores (P <.001). The preinjury IKDC and Lysholm scores were 76.98 ± 11.71 and 89.26 ± 8.91, respectively. The mean change in anterior knee laxity using a knee arthrometer at 134 and 250 N was −4.03 ± 0.18 mm and −3.63 ± 0.16, respectively. There were 3 cases of a rerupture with a severe pivot shift on the clinical examination. None of these patients underwent revision per the patient's preference. Increased knee recurvatum was observed in one-third of the patients, but all were asymptomatic. Conclusion: In the setting of chronic ACL-deficient knees, PTS reduction (ACW-HTO) with revision ACLR restored knee stability and improved function with an acceptable rate of specific complications. Increased knee recurvatum was observed in one-third of the patients, but all were asymptomatic. Also, approximately half of the patients were able to return to impact sports. [ABSTRACT FROM AUTHOR]

Background: After anterior cruciate ligament reconstruction (ACLR), altered surgical knee biomechanics during running is common. Although greater quadriceps strength is associated with more symmetrical running knee kinetics after ACLR, abnormal running mechanics persist even after resolution of quadriceps strength deficits. As running is a submaximal effort task characterized by limited time to develop knee extensor torque, quadriceps rate of torque development (RTD) may be more closely associated with recovery of running knee mechanics than peak torque (PT). Purpose: To assess the influence of recovery in quadriceps PT and RTD symmetry on knee kinematic and kinetic symmetry during running over the initial 2 years after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 39 Division I collegiate athletes (106 testing sessions; 19 female) completed serial isometric performance testing and running analyses between 3 and 24 months after ACLR. Athletes performed maximal and rapid isometric knee extension efforts with each limb to assess PT and RTD between-limb symmetry indices (PTLSI and RTDLSI), respectively. Peak knee flexion difference (PKFDIFF) and peak knee extensor moment limb symmetry index (PKEMLSI) during running were computed. Multivariable linear mixed-effects models assessed the influence of PTLSI and RTDLSI on PKFDIFF and PKEMLSI over the initial 2 years after ACLR. Results: Significant main effects of RTDLSI (P <.001) and time (P ≤.02) but not PTLSI (P ≥.24) were observed for both PKFDIFF and PKEMLSI models. For a 10% increase in RTDLSI, while controlling for PTLSI and time, a 0.9° (95% CI, 0.5°-1.3°) reduction in PKFDIFF and a 3.5% (95% CI, 1.9%-5.1%) increase in PKEMLSI are expected. For every month after ACLR, a 0.2° (95% CI, 0.1°-0.4°) reduction in PKFDIFF and a 1.3% (95% CI, 0.6%-2.0%) increase in PKEMLSI are expected, controlling for PTLSI and RTDLSI. Conclusion: Quadriceps RTDLSI was more strongly associated with symmetrical knee biomechanics during running compared with PTLSI or time throughout the first 2 years after ACLR. [ABSTRACT FROM AUTHOR]

Background: Following anterior cruciate ligament reconstruction (ACLR), many athletes do not return to their sport, often driven by concerns about re-injury. Psychological support strategies might help, but are not routinely included in rehabilitation after ACLR. The BAck iN the Game (BANG) intervention is a 24-week eHealth program delivered via smartphone application (app), beginning directly after ACLR, with a self-directed approach that aims to target the specific challenges athletes encounter in rehabilitation. Aim: To describe athletes' experiences of using the BANG app during rehabilitation, to support returning to sport following ACLR. Method: Participants were athletes, in contact and/or non-contact pivoting sports, who had ACLR with the goal to return to sports. Semi-structured, individual interviews were conducted 6–10 months after their ACLR; all had access to the BANG intervention. Verbatim transcripts were analysed with a qualitative content analysis. Results: The 19 participants were 17–30 years, mean 21.6 years (SD 3.5); 7 men and 12 women. The analysis generated three main categories. (A) Interacting with the app illustrated how, when, or why the participants engaged with the app. The app was helpful because of its varying content, the notifications served as reminders and participants stopped using the app when no longer needing it. (B) Challenging experiences with the app illustrated that the app itself came with some difficulties e.g., content not appearing with the right timing and material not tailored to their sport. (C) Supportive experiences with the app reflected how the app facilitated the participants' rehabilitation progress; it included positive aspects of the app content and navigation, boosting their confidence to return to sport, and motivated them to continue with rehabilitation. Conclusion: The analysis of the interviews illustrates athletes' awareness in interacting with, and the challenging and supportive experiences of using the app. The BANG app might provide support for returning to sport, primarily psychological support, as an adjunct to regular physiotherapy-guided rehabilitation. Athletes' experiences of the BANG app could be improved by healthcare professionals providing additional advice about when to use which content and why. Trial registration: ClinicalTrials.gov, NCT03959215. Registered 22 May 2019. [ABSTRACT FROM AUTHOR]

Purpose: Return to preinjury levels of performance (RTP) is the main goal after anterior cruciate ligament reconstruction (ACL-R) for athletes when ACL graft rupture is a career-threatening event. The purpose of this study was to elucidate the associated factors for RTP and subsequent ACL injury after ACL-R using bone-patellar tendon-bone (BPTB) or hamstring (HT) autograft in high-level athletes with a minimum postoperative follow-up of 24 months., Methods: This retrospective study included 157 patients who had preinjury Tegner activity level of 9 and underwent primary ACL-R using BPTB (average age, 16.9 years; 35 males and 36 females) or HT (average age, 17.2 years; 49 males and 37 females). The mean follow-ups were 33.6 months in BPTB and 44.5 months in HT, respectively. The data were obtained based on routine clinical follow-ups and telephone interviews performed by the surgeon. Multivariate logistic regression analysis was conducted to determine the association of patient variables with RTP and subsequent ACL injury., Results: Ninety-nine patients (63.1%) were able to RTP. The rate of RTP in BPTB (74.6%) was significantly higher than that of HT (53.5%) (p < 0.05). The overall average timing of RTP after ACL-R was 10.0 months while that was significantly earlier in BPTB (9.7 months) than in HT (10.5 months) (p < 0.05). Twenty-three (14.6%) and 21 patients (13.4%) had ACL graft ruptures and ACL injuries in the contralateral knees, respectively. Multivariate analyses showed that BPTB (odds ratio [OR], 2.590; 95% confidence interval [CI], 1.300-5.160; p = 0.007) was associated with a higher potential for RTP after ACL-R. The incidence of ACL graft rupture after ACL-R decreased with BPTB (OR, 0.861; 95% CI, 0.770-0.962; p = 0.009)., Conclusions: The use of BPTB autograft was associated with a higher rate of RTP and a lower incidence of ACL graft rupture compared to ACL-R using HT autograft., Level of Evidence: Level IV, retrospective case series., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

While there has been significant interest in the documentation of return to sport outcomes following anterior cruciate ligament (ACL) injury, the elite level female athlete has not been a focus of this research. This is despite women being at increased risk for ACL injury and considerable global growth in women participating in sport. Therefore, the focus of this review was to examine the available literature regarding return to sport outcomes in elite level women with an ACL injury. The topics of discussion focus on return to sport rates, timing and determinants of return to sport, longevity of play, return to sport performance, and further ACL injury. Knee health in the longer term is also briefly discussed along with the limitations of the existent literature.

Background: Generalised joint hypermobility (GJH) has been associated with an increased risk of suffering an anterior cruciate ligament (ACL) injury. Patients with GJH exhibit lower muscle strength and poorer scores for patient-reported outcomes after ACL reconstruction, compared with patients without GJH. The aim of this study was to examine differences in the percentages of patients who return to sport (RTS) or pre-injury level of activity (RTP), muscle function and patient-reported outcomes at the time of RTS or RTP, as well as the time of RTS or RTP in patients with GJH compared with patients without GJH in the first two years after ACL reconstruction. Methods: This prospective study used data from an ACL- and rehabilitation-specific register located in Gothenburg, Sweden. Patients aged between 16 and 50, who had a primary ACL injury treated with reconstruction, were included. Data up to two years after ACL reconstruction were used and consisted of achieving RTS and RTP, results from isokinetic muscle function tests for knee extension and flexion and patient-reported outcomes (Knee Self-Efficacy Scale, Knee injury and Osteoarthritis Outcome Score and ACL-Return to Sport after Injury scale) at the time of RTS, as well as the time of RTP. A Beighton Score of ≥ 5/9 was used to define GJH. A Tegner Activity Scale of ≥ 6 was used to define RTS, while a Tegner equal to or above pre-injury level was used to define RTP. Results: A total of 1,198 patients (54.7% women) with a mean age of 28.5 ± 8.6 years were included. A smaller proportion of patients with GJH achieved RTS compared with patients without GJH (49.2% vs. 57.3%, Odds ratio: 0.720, p = 0.041). Furthermore, patients with GJH were marginally less symmetrical on the knee extension strength test, expressed as a Limb Symmetry Index, at the time of RTP compared with patients without GJH (87.3 ± 13.5 vs. 91.7 ± 14.3, Cohen's d = 0.142, p = 0.022). No further differences were found between groups regarding any muscle function tests or patient-reported outcomes. Conclusion: A smaller proportion of patients with GJH achieved RTS compared with patients without GJH. Patients with GJH displayed less symmetrical knee extension strength at the time of RTP compared with patients without GJH. [ABSTRACT FROM AUTHOR]

Background: Although objective outcomes assessing knee function are essential measurements for return to sport, psychological factors have become increasingly recognized as equally important parameters for determining an athlete's ability to return to sport after surgery. Purpose: To systematically review the literature to determine whether patients who returned to sport after anterior cruciate ligament (ACL) reconstruction had improved psychological scores (as measured with validated questionnaires) compared with patients who did not return to sport. Study Design: Systematic review and meta-analysis; Level of evidence, 3. Methods: A systematic review was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and was preregistered on PROSPERO. Four databases were searched for level 1 to 3 studies that compared at least 1 psychological outcome measured by a validated questionnaire for patients who did and did not return to sport after primary ACL reconstruction. The following data were recorded: study and patient characteristics; psychological metrics (ACL–Return to Sport Injury [ACL-RSI] scale, Knee Self-Efficacy Scale [K-SES], and Tampa Scale of Kinesiophobia [TSK/TSK-11]); International Knee Documentation Committee (IKDC) score; and clinical metrics. Study methodological quality was analyzed using the methodological index for non-randomized studies (MINORS), and the mean difference (MD) and 95% CI were calculated for each psychological outcome score using the inverse variance method. Results: We included and analyzed 16 articles (3744 patients; 38.9% female; mean age range, 17-28.7 years; mean MINORS score, 19.9 ± 1.4). Overall, 61.8% of athletes returned to sport (66.8% of male patients; 55.4% of female patients). Patients who returned scored significantly higher on the ACL-RSI scale (MD, 20.8; 95% CI, 15.9 to 25.7; P <.001), significantly higher on the K-SES (MD, 1.3; 95% CI, 0.2 to 2.3; P =.036), and significantly lower on the TSK/TSK-11 (MD, 10.1%; 95% CI, −12.1% to −8.2%; P =.004). Those returning to sport did not exceed the minimal clinically important difference for IKDC score versus those not returning to sport. Conclusion: Patients who returned to sport after primary ACL reconstruction had significantly higher psychological readiness, higher self-efficacy, and lower kinesiophobia compared with those who did not return to sport, despite having clinically similar knee function scores. Evaluation of psychological readiness, in combination with other objective measurements, is a critical component of return-to-sport evaluation in athletes after primary ACL reconstruction. Registration: CRD42021284735 (PROSPERO). [ABSTRACT FROM AUTHOR]

Patellofemoral joint (PFJ) osteoarthritis is common following anterior cruciate ligament reconstruction (ACLR) and may be linked with altered joint loading. However, little is known about the cross‐sectional and longitudinal relationship between PFJ loading and osteoarthritis post‐ACLR. This study tested if altered PFJ loading is associated with prevalent and worsening early PFJ osteoarthritis post‐ACLR. Forty‐six participants (mean ± 1 SD age 26 ± 5 years) approximately 1‐year post‐ACLR underwent magnetic resonance imaging (MRI) and biomechanical assessment of their reconstructed knee. Trunk and lower‐limb kinematics plus ground reaction forces were recorded during the landing phase of a standardized forward hop. These data were input into a musculoskeletal model to calculate the PFJ contact force. Follow‐up MRI was completed on 32 participants at 5‐years post‐ACLR. Generalized linear models (Poisson regression) assessed the relationship between PFJ loading and prevalent early PFJ osteoarthritis (i.e., presence of a PFJ cartilage lesion at 1‐year post‐ACLR) and worsening PFJ osteoarthritis (i.e., incident/progressive PFJ cartilage lesion between 1‐ and 5‐years post‐ACLR). A lower peak PFJ contact force was associated with prevalent early PFJ osteoarthritis at 1‐year post‐ACLR (n = 14 [30.4%]; prevalence ratio: 1.37; 95% confidence interval [CI]: 1.02–1.85) and a higher risk of worsening PFJ osteoarthritis between 1‐ and 5‐years post‐ACLR (n = 9 [28.1%]; risk ratio: 1.55, 95% CI: 1.13–2.11). Young adults post‐ACLR who exhibited lower PFJ loading during hopping were more likely to have early PFJ osteoarthritis at 1‐year and worsening PFJ osteoarthritis between 1‐ and 5‐years. Clinical interventions aimed at mitigating osteoarthritis progression may be beneficial for those with signs of lower PFJ loading post‐ACLR. [ABSTRACT FROM AUTHOR]

Background: Even elite athletes, who usually show stable postural control, sometimes cannot control their posture after high-load training. This instability may contribute to anterior cruciate ligament injury. Purpose/Hypothesis: The purpose of this study was to evaluate the landing posture of elite female soccer players before and after a novel high-intensity fatigue-inducing exercise protocol. We hypothesized that the landing posture will change before versus after the fatigue protocol. Study Design: Descriptive laboratory study. Method: The study participants were 20 female elite soccer players. All athletes performed 3 drop vertical jumps (DVJs), pedaled an ergometer 8 times with full force for 10 seconds each (fatigue protocol), and then repeated the 3 DVJs. We measured and compared the athletes' blood lactate levels before and after the fatigue protocol, as well as the hip flexion, knee flexion, and ankle dorsiflexion angles and final landing posture during the DJVs. Results: Blood lactate levels increased significantly pre- to postprotocol (from 2.7 ± 1.9 to 15.0 ± 3.6 mmol/L; P <.001), while there were decreases in hip flexion angle (from 35.0° ± 11.2° to 22.4° ± 8.8°; P <.001) and ankle dorsiflexion angle (from 26.4° ± 3.9° to 20.0° ± 3.7°; P <.001). The number of athletes who could not maintain a stable DVJ final landing posture increased from 10% before the fatigue protocol to 70% after. Conclusion: The elite female athletes in our study showed significant decreases in hip flexion and ankle dorsiflexion angles in the DVJ landing after a fatigue-inducing protocol. Most elite athletes were unable to maintain a stable posture on the DVJ landing after the fatigue protocol. Clinical Relevance: This study advances our understanding of how elite athletes land in a fatigued state. [ABSTRACT FROM AUTHOR]

This study aims to determine if baseline T1ρ and T2 will predict cartilage morphological lesion progression in the patellofemoral joint (PFJ) and patient‐reported outcomes at 2‐year after anterior cruciate ligament (ACL) reconstruction (ACLR). Thirty‐nine ACL‐injured patients were studied at baseline and two‐year after ACLR. 3 T MR T1ρ and T2 images and Knee Injury and Osteoarthritis Outcome Score (KOOS) were acquired at both time points. Voxel‐based relaxometry (VBR) technique was used to detect local cartilage abnormalities. Patients were divided into progression and non‐progression groups based on changes of the whole‐organ magnetic resonance imaging scoring (WORMS) grading of cartilage in PFJ from baseline to 2‐year, and into lower (more pain) and higher (less pain) KOOS pain groups based on 2‐year KOOS pain scores, separately. Voxel‐based analyses of covariance were used to compare T1ρ and T2 values at baseline between the defined groups. Using VBR analysis, the progression group at 2‐year showed higher T1ρ and T2 compared with the non‐progression group at baseline, with the medial femoral condyle showing the largest areas with significant differences. At two‐year, 56% of patients were able to recover with respect to KOOS pain. The lower KOOS pain group at 2‐year showed significantly elevated T1ρ and T2 in the patella at baseline compared with the higher KOOS pain group. In conclusion, baseline T1ρ and T2 mapping, combined with VBR analysis, may help identify ACLR patients at high risk of developing progressive PFJ cartilage lesions and worse clinical symptoms 2‐year after surgery. [ABSTRACT FROM AUTHOR]

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