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Background: Non-contact anterior cruciate ligament (ACL) injuries are a major concern in sport-related activities due to dynamic knee movements. There is a paucity of finite element (FE) studies that have accurately replicated the knee geometry, kinematics, and muscle forces during dynamic activities. The objective of this study was to develop and validate a knee FE model and use it to quantify the relationships between sagittal plane knee kinematics, kinetics and the resulting ACL strain., Methods: 3D images of a cadaver knee specimen were segmented (bones, cartilage, and meniscus) and meshed to develop the FE model. Knee ligament insertion sites were defined in the FE model via experimental digitization of the specimen's ligaments. The response of the model was validated against multiple physiological knee movements using published experimental data. Single-leg jump landing motions were then simulated on the validated model with muscle forces and kinematic inputs derived from motion capture and rigid body modelling of ten participants., Results: The maximum ACL strain measured with the model during jump landing was 3.5 ± 2.2%, comparable to published experimental results. Bivariate analysis showed no significant correlation between body weight, ground reaction force and sagittal plane parameters (such as joint flexion angles, joint moments, muscle forces, and joint velocity) and ACL strain. Multivariate regression analysis showed increasing trunk, hip and ankle flexion angles decreases ACL strain (R 2  = 90.04%, p < 0.05)., Conclusions: Soft landing decreases ACL strain and the relationship could be presented through an empirical equation. The model and the empirical relation developed in this study could be used to better predict ACL injury risk and prevention strategies during dynamic activities., (© 2024. The Author(s).)

Purpose: To identify MRI-detected anatomical risk factors for non-contact anterior cruciate ligament (ACL) injuries across genders., Methods: A retrospective analysis was performed on 141 ACL-reconstructed patients (35 females, 106 males) and 142 controls (37 females, 105 males) from January 2020 to April 2022. Inclusion criteria were primary non-contact ACL injuries. The tibial plateau slope, lateral femoral condyle index, Insall-Salvati index, and patellar tendon angle were measured, using binary logistic regression for gender-specific risk evaluation., Results: Increased lateral tibial plateau slope, reduced intercondylar notch width index, lateral femoral condyle index, and patellar tendon angle correlated with ACL injuries in both genders. The Insall-Salvati index was a significant risk factor in females but not in males., Conclusion: This study identifies the lateral tibial plateau slope, notch width index, lateral femoral condyle index, and patellar tendon angle at near-extension as risk factors for ACL injuries in both genders, with the Insall-Salvati index also implicated in females., (© 2024. The Author(s).)

Background: There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR)., Purpose/hypothesis: This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population. The authors' hypothesized there would be differences in DVJ biomechanics between athletes depending on the type of autograft used., Study Design: Controlled laboratory study., Methods: Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3-dimensional computerized marker system were assessed at 6 months after ACLR and compared with the uninjured contralateral limb., Results: A total of 155 participants were included. There were no significant differences in terms of age, sex, or affected leg ( P ≥ .1973) between groups. The HT group was significantly associated with a larger knee valgus moment at initial contact compared with the QT group (28 × 10 -2 vs -35 × 10 -2 N·m/kg, respectively; P = .0254) and a significantly larger maximum hip adduction moment compared with the QT with bone block group (30 × 10 -2 vs -4 × 10 -2 N·m/kg, respectively; P = .0426). Both the QT with bone block (-12 × 10 -2 vs -3 × 10 -2 N·m/kg, respectively; P = .0265) and QT (-13 × 10 -2 vs -3 × 10 -2 N·m/kg, respectively; P = .0459) groups demonstrated significantly decreased mean knee extension moments compared with the HT group., Conclusion: The findings of this study suggest that utilizing an HT autograft resulted in a significantly increased knee valgus moment at initial contact compared with a QT autograft without bone block at 6 months after ACLR in adolescent patients performing a DVJ. A QT autograft was found to be associated with significantly decreased extensor mechanism function compared with an HT autograft., Clinical Relevance: This study adds unique kinematic and kinetic information regarding various ACLR autograft options and highlights the biomechanical deficits that should be taken into consideration in rehabilitation., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: S.V.T. has received support for education from ImpactOrtho and hospitality payments from Stryker. J.V. has received support for education from ImpactOrtho and Goode Surgical and hospitality payments from Smith & Nephew. J.C.B. has received support for education from ImpactOrtho and hospitality payments from Stryker. A.C. has received consulting fees from Arthrex and Zimmer Biomet. J.M.T. has received consulting fees from Arthrex, DePuy Synthes, and Medical Device Business Services; royalties from Arthrex; and support for education from ImpactOrtho, Paladin Technology Solutions, Supreme Orthopedic Systems, and Goode Surgical. H.M. has received consulting fees from Medical Device Business Services and support for education from ImpactOrtho and Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Purpose: The outcomes of anterior cruciate ligament reconstruction in the setting of multiligamentous knee injury (M-ACLR) have not been well characterized compared to isolated ACLR (I-ACLR). This study aims to characterize and compare short-term outcomes between I-ACLR and M-ACLR., Methods: This is a retrospective cohort analysis of the American College of Surgeons National Surgical Quality Improvement Program database from 2005 to 2017. Current Procedural Terminology codes were used to identify and compare elective I- and M-ACLR patients, excluding patients undergoing concomitant meniscal or chondral procedures. Patient demographics and outcomes after I- and M-ACLR were compared using bivariate analysis. Multiple logistic regression analyzed if multiligamentous ACLR was an independent risk factor for adverse outcomes., Results: There was a total of 13,131 ACLR cases, of which 341 were multiligamentous cases. The modified fragility index-5 was higher in multiligamentous ACLR (p < 0.001). Multiligamentous ACLR had worse perioperative outcomes, with higher rate of all complications (3.8%, p = 0.013), operative time > 1.5 h (p < 0.001), length of stay (LOS) ≥ 1 day (p < 0.001), wound complication (2.1%, p = 0.001), and intra- or post-op transfusions (p < 0.001). In multiple logistic regression, multiligamentous ACLR was an independent risk factor for LOS ≥ 1 (odds ratio [OR] 5.8), and intra-/post-op transfusion (OR 215.1) and wound complications (OR 2.4). M-ACLR was not an independent risk factor for any complication, reoperation at 30 days, readmission, urinary tract infection (UTI), or venous thromboembolism (VTE)., Conclusion: M-ACLR generally had worse outcomes than I-ACLR, including longer LOS, need for perioperative transfusions, and wound complications., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: An athlete who returns to sport after an anterior cruciate ligament (ACL) injury has a substantially high risk of sustaining a new secondary ACL injury. Because ACL injuries most frequently occur during cutting maneuvers, such movements should be at the center of research attention., Purpose: To investigate whether knee biomechanical parameters during side-step cutting maneuvers differ between female elite athletes with and without a history of ACL injury and to evaluate whether such parameters are associated with future secondary ACL injury., Study Design: Cohort study; Level of evidence, 2., Methods: A total of 756 female elite handball and soccer players, of whom 76 had a history of ACL injury, performed a sport-specific cutting task while 3-dimensional kinematics and kinetics were measured. ACL injuries were registered prospectively over an 8-year follow-up period. Seven knee-specific biomechanical variables were the basis for all analyses. Two-way analyses of variance were applied to assess group differences, whereas logistic regression models served to evaluate associations between the knee-specific variables and future secondary ACL injury., Results: When players with a previous ACL injury performed the cutting maneuver with their ipsilateral leg, they exhibited lower knee abduction angles (mean difference [MD], 1.4°-1.5°; 95% CI, 0.2°-2.9°), lower peak knee flexion moments (MD, 0.33 N·m/kg -1 ; 95% CI, 0.18-0.48 N·m/kg -1 ), lower peak knee abduction moments (MD, 0.27 N·m/kg -1 ; 95% CI, 0.12-0.41 N·m/kg -1 ), and lower peak knee internal rotation moments (MD, 0.06 N·m/kg -1 ; 95% CI, 0.01-0.12 N·m/kg -1 ) compared with injury-free players. When players performed the cut with their contralateral leg, no differences were evident ( P < .05). None of the 7 knee-specific biomechanical variables was associated with future secondary ACL injury in players with an ACL injury history ( P < .05)., Conclusion: Approximately 4 years after ACL injury, female elite team-ball athletes still unloaded their ipsilateral knee during cutting maneuvers, yet contralateral knee loading was similar to that of injury-free players. Knee biomechanical characteristics were not associated with future secondary ACL injury., Competing Interests: The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Objectives: To compare the injury profiles of football players shifting between second and first teams with those of second- and first-team players, and to examine the opinions of shifting players., Design: Prospective cohort study., Methods: 170 male players from Athletic Club (second team = 90, shifting = 20, first team = 60) were followed over eight seasons. Injuries and exposure time were recorded following the FIFA consensus, and 18 shifting players answered a seven-item questionnaire on their experience., Results: 35 % shifting players became full-time first-team players, in contrast to only 8 % of second-team players (odds ratio = 6.4, p < 0.01). There were no differences in the overall injury incidence, but the overall burden of injuries was higher in second-team (172 days lost/1000 h) and shifting players (194 days lost/1000 h) compared with first-team players (114 days lost/1000 h, p < 0.01). Shifting players had a higher burden of knee joint/ligament injuries compared with first-team players (137 vs. 18 days lost/1000 h, p < 0.01) and anterior cruciate ligament (ACL) ruptures (122 vs. 10 days lost/1000 h, p < 0.01). There was a trend towards a higher burden of ACL ruptures in shifting players than in second-team players (122 vs. 41 days lost/1000 h, p = 0.07). Shifting players reported constant pressure and better communication with the second-team coaching staff than with the first-team staff., Conclusions: The high burden of injuries in shifting players, particularly from ACL ruptures, highlights the need for action. Ensuring high-quality communication between second- and first-team staff remains a key challenge., Competing Interests: Declaration of interest statement The authors declare that they have no competing interests., (Copyright © 2023 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Background: Numerous graft options are available when undertaking anterior cruciate ligament (ACL) reconstruction (ACLR), although a lack of high-quality evidence exists comparing quadriceps (QT) and hamstring (HT) autografts., Purpose: To investigate patient outcomes in patients undergoing HT versus QT ACLR., Study Design: Randomized controlled trial; Level of evidence, 1., Methods: After recruitment and randomization, 112 patients (HT = 55; QT = 57) underwent ACLR. Patients were assessed pre- and postoperatively (6 weeks and 3, 6, 12, and 24 months), with a range of patient-reported outcome measures (PROMs), graft laxity (KT-1000 arthrometer; primary outcome variable), active knee flexion and extension range of motion (ROM), peak isokinetic knee extensor and flexor strength, and a 6-hop performance battery. Limb symmetry indices (LSIs) were calculated for strength and hop measures. Secondary procedures, ACL retears, and contralateral ACL tears were reported., Results: All PROMs and knee ROM measures significantly improved ( P < .0001), and no other group differences ( P > .05) were observed-apart from the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) score, which was significantly better in the HT group at 3 ( P = .008), 6 ( P = .010), and 12 ( P = .014) months. No significant changes were observed in side-to-side laxity from 6 to 24 months ( P = .105), and no group differences were observed ( P = .487) at 6 (HT mean, 1.2; QT mean, 1.3), 12 (HT mean, 1.1; QT mean, 1.3), and 24 (HT mean, 1.1; QT mean, 1.2) months. While the HT group demonstrated significantly greater ( P < .05) quadriceps strength LSIs at 6 and 12 months, the QT group showed significantly greater ( P < .05) hamstring strength LSIs at 6, 12, and 24 months. The HT group showed significantly greater ( P < .05) LSIs for the single horizontal (6 months), lateral (6 and 12 months), and medial (6 months) hop tests for distance. Up until 24 months, 1 patient (QT at 22 months) had a retear, with 2 contralateral ACL tears (QT at 19 months; HT at 23 months). Secondary procedures included 5 in the HT group (manipulation under anesthesia, notch debridement, meniscal repair, and knee arthroscopy for scar tissue) and 6 in the QT group (notch debridement, meniscal repair, knee arthroscopy for scar tissue, tibial tubercle transfer, and osteochondral autologous transplantation)., Conclusion: Apart from the ACL-RSI, the 2 autograft groups compared well for PROMs, knee ROM, and laxity. However, greater hamstring strength LSIs were observed for the QT cohort, with greater quadriceps strength (and hop test) LSIs in the HT cohort. The longer-term review will continue to evaluate return to sports and later-stage reinjury between the 2 graft constructs., Registration: ACTRN12618001520224p (Australian New Zealand Clinical Trials Registry)., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A research grant was awarded from the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) to assist this study (grant ID 2019-75). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Purpose: To assess the statistical fragility of recently published randomized controlled trials (RCTs) comparing the use of hamstring tendon autograft with bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction., Methods: The PubMed, Embase, and MEDLINE databases were queried for RCTs published since 2010 comparing autograft type (bone-patellar tendon-bone vs hamstring tendon) in ACL reconstruction surgery. The fragility index (FI) and reverse FI (rFI) were determined for significant and nonsignificant outcomes, respectively, as the number of outcome reversals required to change statistical significance. The fragility quotient (FQ) and reverse FQ, representing fragility as a proportion of the study population, were calculated by dividing the FI and rFI, respectively, by the sample size., Results: We identified 19 RCTs reporting 55 total dichotomous outcomes. The median FI of the 55 total outcomes was 5 (interquartile range [IQR], 4-7), meaning a median of 5 outcome event reversals would alter the outcomes' significance. Five outcomes were reported as statistically significant with a median FI of 4 (IQR, 2-6), meaning a median of 4 outcome event reversals would change outcomes to be nonsignificant. Fifty outcomes were reported as nonsignificant with a median rFI of 5 (IQR, 4-7), meaning a median of 5 outcome event reversals would change outcomes to be significant. The FQ and reverse FQ for significant and nonsignificant outcomes were 0.025 (IQR, 0.018-0.045) and 0.082 (IQR, 0.041-0.106), respectively. For 61.8% of outcomes, patients lost to follow-up exceeded the corresponding FI or rFI., Conclusions: There is substantial statistical fragility in recent RCTs on autograft choice in ACL reconstruction surgery given that altering a few outcome events is sufficient to reverse study findings. For over half of outcomes, maintaining patients lost to follow-up may have been sufficient to reverse study conclusions., Clinical Relevance: We recommend co-reporting FIs and P values to provide a more comprehensive representation of a study's conclusions when conducting an RCT., (Copyright © 2023 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: Analyzing sports injuries is essential to mitigate risk for injury, but inherently challenging using in vivo approaches. Computational modeling is a powerful engineering tool used to access biomechanical information on tissue failure that cannot be obtained otherwise using traditional motion capture techniques., Methods: We extrapolated high-risk kinematics associated with ACL strain and cartilage load and stress from a previous motion analysis of 14 uninjured participants. Computational simulations were used to induce ACL failure strain and cartilage failure load, stress, and contact pressure in two age- and BMI-matched participants, one of each biological sex, during single-leg cross drop and single-leg drop tasks. The high-risk kinematics were exaggerated in 20% intervals, within their physiological range of motion, to determine if injury occurred in the models. Where injury occurred, we reported the kinematic profiles that led to tissue failure., Findings: Our findings revealed ACL strains up to 9.99%, consistent with reported failure values in existing literature. Cartilage failure was observed in all eight analyzed conditions when increasing each high-risk kinematic parameter by 2.61 ± 0.67 times the participants' natural landing values. The kinematics associated with tissue failure included peak hip internal rotation of 22.48 ± 19.04°, peak hip abduction of 22.51 ± 9.09°, and peak lumbar rotation away from the stance limb of 11.56 ± 9.78°., Interpretation: Our results support the ability of previously reported high-risk kinematics in the literature to induce injury and add to the literature by reporting extreme motion limits leading to injurious cases. Therefore, training programs able to modify these motions during single-leg landings may reduce the risk of ACL injury and cartilage trauma., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Secondary injury of the anterior cruciate ligament (ACL) is a common concern after anterior cruciate ligament (ACL) reconstruction, and identification of morphological risk factors is essential to prevent these injuries. We hypothesized that abnormal femoral trochlea morphology is associated with secondary ACL injuries after reconstruction. This study aimed to investigate the relationship between femoral trochlear morphology and secondary ACL injuries after reconstruction. A retrospective analysis was conducted on 20 patients who experienced secondary ACL injuries after reconstruction in our hospital between 2017 and 2022 (experimental group), and 40 patients were included in the control group. The following femoral trochlear characteristics were compared between the 2 groups: medial condylar height (MCH), trochlear sulcus height (TSH), lateral condylar height (LCH), trochlear sulcus depth (TSD), trochlear sulcus angle (TSA), medial trochlear inclination (MTI), and lateral trochlear inclination (LTI). The study found that patients in the secondary ACL injury after reconstruction group exhibited the following differences when compared to the control group: decreased MCH (56.33 ± 3.52 vs 59.93 ± 3.24, P value = .015), decreased TSD (4.89 ± 1.56 vs 6.98 ± 1.23, P value ˂ .001), decreased MTI (12.54 ± 6.57 vs 19.45 ± 6.35, P value ˂ .001), and increased TSA (145.23 ± 9.76 vs 139.25 ± 8.42, P value ˂ .001). This study demonstrated a significant correlation between abnormal femoral trochlear morphological characteristics and secondary ACL injuries after reconstruction. Decreased MCH, TSD, and MTI along with increased TSA are associated with a higher risk of secondary ACL injury. These data could thus help identify individuals susceptible to secondary ACL injuries after reconstruction., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Large data analysis of anterior cruciate ligament reconstruction (ACLR) short-term complications on age will help surgeons stratify and counsel at-risk patients. The purpose of this study is to assess if older patients are at greater risk for short-term complications after ACLR., Methods: This retrospective cohort study included patients who underwent elective ACLR with or without concomitant meniscal procedures in the National Surgical Quality Improvement Program from 2005 to 2017. Patients were divided into age groups 16-30, 31-45, and > 45. Modified fragility index-5 (mFI-5), demographics and short-term outcomes were examined with bivariate and multivariate analysis to determine if age was a risk factor for complications., Results: A total of 23,581 patients (35.4% female) were included in this analysis. Mean age was 32.1 ± 10.8 years. Older patients had higher mFI-5 scores (p < 0.001), shorter operative times (p < 0.001), lower use of only general anesthesia (p < 0.001). The oldest patients had similar rates of complications as the two younger groups. Older age was an independent risk factor for VTE, but decreased risk of prolonged operations. A mFI-5 > 0 increased risk factors for readmission (Odds ratio 2.2, P = 0.006). Infection was the most common cause 30-day readmissions (40/135, 29.6%)., Conclusion: In the early postoperative period, older age is an independent risk factor for VTE and younger age is a significant factor for prolonged surgeries. Having an mFI-5 > 0 increased risk factors for readmission., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [CA receives IP royalties, is a Paid consultant, and conducts Research support from Arthrex, Inc; he owns stock or options for Peak; He receives publishing royalties, financial or material support from Lead Player; he conducts research support for Major League Baseball; he is on the editorial or governing board for Orthopedics Today; he conducts research support for Stryker. TSL is a Board or committee member of American Orthopaedic Society for Sports Medicine; he is a paid consultant for CONMED Linvatec and Smith & Nephew. The remaining authors have no disclosures.], (Copyright © 2023 Elsevier B.V. All rights reserved.)

In recreational alpine skiing, an ACL injury represents the most common injury. Skiing is a complex activity where the skier interacts with the environment, such as weather, snow conditions, temperature, etc. Thus, the aim of this study was to evaluate the potential impact of environmental factors on ACL injury risk in recreational alpine skiers. Among a cohort of 392 ACL-injured skiers and 392 uninjured controls matched for sex and skiing skill, environmental factors were collected by questionnaire. Factors included weather conditions, snow conditions, perceived temperature, and slope difficulty at the time-point of the accident (ACL-injured skiers) or of questioning during the ski day (uninjured controls).Multiple logistic regression revealed that in addition to age, five environmental factors were significantly predictive of an ACL injury: fresh snow (OR 10.5), grippy snow (OR 7.8), icy slope condition (OR 12.4), very cold/cold perceived temperature (OR 1.6), and skiing on easy slopes (OR 6.9). In conclusion, besides age, environmental factors such as fresh and grippy snow, icy slope conditions, low temperatures, and flat slopes are associated with an increased ACL injury risk in recreational alpine skiing. Those factors are at least partly modifiable and should be taken into consideration for preventive strategies., Competing Interests: The authors declare that they have no conflict of interest., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Purpose: The results after anterior cruciate ligament reconstruction (ACLR) are evaluated by laxity measures, functional tests, and patients' perception by patient-reported outcome measures (PROMs). It is not known, if one of these evaluation instruments is representative or if outcome scores from all must be reported to obtain a full evaluation of the condition. The aim was to study the correlations between these three types of outcomes 1 year after primary ACLR., Method: All adult patients (range 18-45 years) who had an ACLR between 1.1.2019 and 31.12.2021 were offered 1-year follow-up by an independent observer. Preoperative information about knee laxity and peroperative information about the condition of menisci and cartilage were registered. At 1-year follow-up clinical and instrumented knee stability and function assessed by four different hop tests were registered. Patients completed four PROMs (the Subjective International Knee Documentation Committee (IKDC) score, the Knee Numeric-Entity Evaluation Score (KNEES-ACL), the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm score) and Tegner activity scale and answered anchor questions regarding satisfaction and willingness to repeat the operation., Results: A total of 190 adults attended the 1-year follow-up and 151 had all assessments. There were only a few positive and weak correlations between performance tests and PROMS and between clinical measurements and PROMS (r = 0.00-0.38), and the majority were of negligible strength. Tegner score had in general the highest correlation (low to moderate). The highest correlation was 0.53 (moderate) between the anchor question about patient satisfaction and Lysholm/IKDC scores. There was no difference in the correlations depending on meniscal condition., Conclusions: In ACLR patients there was no clinically relevant correlation between scores obtained by PROMs, a battery of functional performance tests and instrumented laxity of the knee at 1-year follow-up. Therefore, one type of outcome cannot represent the others. This is an argument for always to include and report all three types of outcomes, and conclusions based on one type of outcome may not be sufficient., Level of Evidence: II., (© 2023. The Author(s).)

Introduction: Anterior cruciate ligament (ACL) injury is common within the US military and represents a significant loss to readiness. Since recent changes to operational tempo, there has not been an analysis of ACL injury risk. The aim of this retrospective cohort study was to evaluate military occupation, sex, rank and branch of service on ACL injury risk in the US military from 2006 to 2018., Methods: The Defense Medical Epidemiology Database was queried for the number of US tactical athletes with International Classification of Diseases diagnosis codes 717.83 (old disruption of ACL), 844.2 (sprain of knee cruciate ligament), M23.61 (other spontaneous disruption of ACL) and S83.51 (sprain of ACL of knee) on their initial encounter. Relative risk and χ 2 statistics were calculated to assess sex and military occupation effects on ACL injury. A multivariable negative binomial regression model evaluated changes in ACL injury incidence with respect to sex, branch of service and rank., Results: The study period displayed a significant decrease in the ACL injury rate at 0.18 cases per 1000 person-years or relative decrease of 4.08% each year (p<0.001) after averaging over the main and interactive effects of sex, rank and branch of service. The interaction effect of time with sex indicated a steeper decline in the incidence in men as compared with women. The risk of ACL injury by sex was modified by rank. The incidence among military personnel varied by occupation., Conclusion: Despite the decline among tactical athletes over time, rates of ACL injury remain much higher than the general US population. Sex, rank, branch of service and military occupation were found to be risk factors for ACL injury. It is critical for policy makers to understand the salient risk factors for ACL injury to guide proactive measures to prevent injury., Competing Interests: Competing interests: ADA, AJM and JJF are military service members or employees of the US Government. This work was prepared as part of their official duties., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Background: Australia has a high rate of sporting participation. Although this has many benefits, knee injuries are common, particularly in pivoting and contact sports., Objective: This article reviews the management of common sport-related knee injuries, including injuries to the collateral and cruciate ligaments, menisci and the extensor mechanism., Discussion: Some sport-related knee injuries can be treated non-operatively with physiotherapy-led rehabilitation. These include the majority of isolated medial collateral ligament, lateral collateral ligament and posterior cruciate ligament injuries. Other knee injuries might require surgical intervention. These include anterior cruciate ligament ruptures in young patients aiming to return to pivoting sports, certain meniscal tears and extensor mechanism disruptions. A multidisciplinary approach to these injuries will facilitate optimal patient care.

The loss of knee range of motion (ROM) is not an uncommon complication after anterior cruciate ligament reconstruction (ACLR). However, the risk factors of loss of knee ROM remain debatable. The purpose of this study was to evaluate the incidence and risk factors of loss of knee ROM at 12 months after primary ACLR performed after regaining full knee ROM preoperatively. Consecutive patients who underwent primary ACLR after regaining full ROM between January 2014 and January 2020 were retrospectively reviewed. Patients who received a surgical arthrolysis within 12 months after ACLR or those who had a loss of knee ROM at 12 months postoperatively were defined as the loss of ROM group. Possible risk factors of loss of knee ROM, including patient demographic, preoperative, surgical, and postoperative factors, were assessed. The notch wide index and radiographic parameters of the tibial spines; medial tibial spine height/tibial length (TL), lateral tibial spine height (LTSH)/TL, and tibial spine width (TSW)/TL, were also assessed. A total of 141 patients (141 knees) were included (mean age, 25.8 ± 11.4 years; male/female, 56/85). Of the 141 patients, three received surgical arthrolysis within 12 months, and 23 had a loss of knee ROM at 12 months after ACLR. On comparing patients with and without loss of knee ROM, significant differences were found in the age ( p  = 0.04), LTSH/TL ( p  = 0.02), and TSW/TL ( p  = 0.02). A multivariate regression analysis showed that the age (odds ratio [OR]; 1.05, 95% confidence interval [CI]: 1.01-1.09, p  = 0.02), LTSH/TL (OR: 1.44, 95% CI: 1.01-2.1, p  = 0.04), and TSW/TL (OR: 0.79, 95% CI: 0.65-0.97, p  = 0.02) were identified as significant independent risk predictors of loss of knee ROM. This study showed that the incidence of loss of knee ROM at 12 months after primary ACLR was 18.4% (26/141). An older age, a higher LTSH/TL, and a smaller TSW/TL may be associated with loss of knee ROM at 12 months after ACLR., Competing Interests: None declared., (Thieme. All rights reserved.)

Purpose: To investigate the effect of technology-assisted Anterior Cruciate Ligament Reconstruction (ACLR) on post-operative clinical outcomes and tunnel placement compared to conventional arthroscopic ACLR., Methods: CENTRAL, MEDLINE, and Embase were searched from January 2000 to November 17, 2022. Articles were included if there was intraoperative use of computer-assisted navigation, robotics, diagnostic imaging, computer simulations, or 3D printing (3DP). Two reviewers searched, screened, and evaluated the included studies for data quality. Data were abstracted using descriptive statistics and pooled using relative risk ratios (RR) or mean differences (MD), both with 95% confidence intervals (CI), where appropriate., Results: Eleven studies were included with total 775 patients and majority male participants (70.7%). Ages ranged from 14 to 54 years (391 patients) and follow-up ranged from 12 to 60 months (775 patients). Subjective International Knee Documentation Committee (IKDC) scores increased in the technology-assisted surgery group (473 patients; P = 0.02; MD 1.97, 95% CI 0.27 to 3.66). There was no difference in objective IKDC scores (447 patients; RR 1.02, 95% CI 0.98 to 1.06), Lysholm scores (199 patients; MD 1.14, 95% CI - 1.03 to 3.30) or negative pivot-shift tests (278 patients; RR 1.07, 95% CI 0.97 to 1.18) between the two groups. When using technology-assisted surgery, 6 (351 patients) of 8 (451 patients) studies reported more accurate femoral tunnel placement and 6 (321 patients) of 10 (561 patients) studies reported more accurate tibial tunnel placement in at least one measure. One study (209 patients) demonstrated a significant increase in cost associated with use of computer-assisted navigation (mean 1158€) versus conventional surgery (mean 704€). Of the two studies using 3DP templates, production costs ranging from $10 to $42 USD were cited. There was no difference in adverse events between the two groups., Conclusion: Clinical outcomes do not differ between technology-assisted surgery and conventional surgery. Computer-assisted navigation is more expensive and time consuming while 3DP is inexpensive and does not lead to greater operating times. ACLR tunnels can be more accurately located in radiologically ideal places by using technology, but anatomic placement is still undetermined because of variability and inaccuracy of the evaluation systems utilized., Level of Evidence: Level III., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

The monitoring of athletes is crucial to preventing injuries, identifying fatigue or supporting return-to-play decisions. The purpose of this study was to explore the ability of Kohonen neural network self-organizing maps (SOM) to objectively characterize movement patterns during sidestepping and their association with injury risk. Further, the network's sensitivity to detect limb dominance was assessed. The data of 67 athletes with a total of 613 trials were included in this study. The 3D trajectories of 28 lower-body passive markers collected during sidestepping were used to train a SOM. The network consisted of 1247 neurons distributed over a 43 × 29 rectangular map with a hexagonal neighbourhood topology. Out of 61,913 input vectors, the SOM identified 1247 unique body postures. Visualizing the movement trajectories and adding several hidden variables allows for the investigation of different movement patterns and their association with joint loading. The used approach identified athletes that show significantly different movement strategies when sidestepping with their dominant or non-dominant leg, where one strategy was clearly associated with ACL-injury-relevant risk factors. The results highlight the ability of unsupervised machine learning to monitor an individual athlete's status without the necessity to reduce the complexity of the data describing the movement.

Background: Arthrofibrosis can limit function and return to sport after anterior cruciate ligament (ACL) reconstruction. Previously reported risk factors for developing arthrofibrosis after ACL reconstruction include female sex, age <18 years, time from injury to surgery <28 days, concomitant meniscal repair, prolonged immobilization, and genetic factors. There is a lack of evidence regarding whether race plays a significant role., Hypothesis: The risk of undergoing manipulation under anesthesia (MUA) and/or lysis of adhesions (LOA) after primary ACL reconstruction with bone-patellar tendon-bone (BTB) autograft in female basketball players is higher in African American players than in White players., Study Design: Case-control study; Level of evidence, 3., Methods: Using a computerized relational database, the authors identified competitive female basketball players who underwent primary ACL reconstruction with BTB autograft by the senior author over a 13-year period. Data previously entered from examinations and surgical findings were reviewed retrospectively. Univariate statistics and multivariable logistic regression were used to assess the relationship between undergoing subsequent MUA and/or LOA and study predictors., Results: A total of 186 knees (114 African American knees and 72 White knees) met inclusion criteria. The overall rate of MUA and/or LOA was 8.6%. Thirteen African American knees (11.4%) and 3 White knees (4.2%) underwent MUA and/or LOA for treatment of arthrofibrosis. No study predictor was found to have a statistically significant relationship with the rate of MUA and/or LOA on univariate analysis. However, when controlling for body mass index and previously described risk factors (age <18 years, time from injury to surgery ≤28 days, and concomitant meniscal repair) in the logistic regression model, the authors found that MUA and/or LOA was more likely in African American (odds ratio, 4.01 [95% CI, 1.01-15.92]; P = .049) than in White female players and in patients who underwent ACL reconstruction within 28 days of injury (odds ratio, 4.01 [95% CI, 1.18-13.57]; P = .026) compared with those with surgery delayed beyond 28 days., Conclusion: In female basketball players, the present study found a statistically significantly increased risk for undergoing MUA and/or LOA after primary ACL reconstruction with BTB autograft in African American females compared with White females and in patients who underwent ACL reconstruction within 28 days of injury., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: R.M.C. has received support for education from Alon Medical Technology, Medical Device Business Services, and Stryker. A.M.B. has received support for education from Alon Medical Technology. W.J.F. has received support for education from Alon Medical Technology, Arthrex, and Smith & Nephew and a grant from Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Background: Pediatric transphyseal anterior cruciate ligament reconstruction (ACLR) bears several advantages and is widely used. The main concern is the risk of growth disturbance. Our purpose was to investigate the incidence and risk factors of growth disturbance in skeletally immature patients who underwent transphyseal ACLR. We hypothesized that this procedure would generate neither clinically relevant limb length discrepancy (LLD) nor axis deviation., Methods: This prospective, consecutive, single-center series included skeletally immature patients who underwent primary transphyseal ACLR using semitendinosus tendon autograft, with a 2-year follow-up bone length standing radiograph of both lower limbs from pelvis to ankle in anterior posterior view. Lower limb length, mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) were measured. The definition of postoperative growth disturbance was defined as ≥10 mm for LLD or ≥3 degrees for axis deviation in comparison to the contralateral lower limb. Predictive variables included age at surgery, gender, side, and diameter of bone tunnels. Student or Mann-Whitney test was used for numerical variables, and Chi-square test or Fisher exact test was used for categorical variables. P values <0.05 were considered statistically significant., Results: Fifty consecutively treated patients were included. Forty-seven patients (31 boys, 16 girls) with a mean age of 13.2 years (range, 9 to 16) at the time of surgery were available for analysis. Six patients had an LLD of at least 10 mm. Twenty-five patients had a difference in MPTA of a least 3 degrees (range, 5 to 8). Sixteen patients had a difference in LDFA of a least 3 degrees (range, 4 to 9). No patients presented with a clinical deformity or related symptoms. Regarding coronal alignment, there was no statistical difference in mechanical axis deviation, LDFA, or MPTA. Gender, side, age, and bone tunnel diameter did not influence growth disturbance., Conclusions: Transphyseal pediatric ACLR generated a high rate of growth disturbances (leg length discrepancy and axis deviation) although none clinically relevant. Mild proximal tibial axis deviation in patients operated on near skeletal maturity should be further investigated., Level of Evidence: Level III., Study Design: Case-control study., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To critically evaluate the efficacy and safety of early versus delayed anterior cruciate ligament reconstruction (ACLR) for anterior cruciate ligament (ACL) injuries based on the different cut-off values of the timing of operation., Methods: PubMed, Medline, Embase, Cochrane library, China National Knowledge Infrastructure, Chinese Biomedical Literature, and Wanfang Digital Periodical database were searched from inception to November 2022 without language restrictions. Randomized controlled trials (RCTs) and cohort studies (CSs) comparing early ACLR with delayed ACLR for ACL injuries were included., Results: Twenty-four studies (10 RCTs and 14 CSs) were included. According to the information from included studies, 3 weeks, 4 weeks, 6 weeks, 6 months, and 12 months after ACL injuries were considered as the cut-off values of early and delayed ACLR. When 4 weeks were considered as the cut-off value, early ACLR could significantly improve Lysholm score, IKDC score and VAS score at 6 and 12 months postoperatively and decrease the incidence of adverse events compared with delayed ACLR (P < 0.05). However, no statistically significant difference in positive rate of Lachman test and incidence of meniscus injuries and chondral lesions between the two groups when 3 weeks, 6 weeks, 6 months or 12 months after ACL injuries were considered as the cut-off values of early and delayed ACLR (P > 0.05)., Conclusion: The present study suggests that early ACLR, especially conducted within 3-4 weeks after ACL injuries, may be more effective for improving knee function and relieving pain compared with delayed ACLR. More high-quality RCTs are warranted., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ai-Feng Liu reports financial support was provided by National Natural Science Foundation of China. Ai-Feng Liu reports financial support was provided by Basic Scientific Research Project of Public Welfare on Central Level of Chinese Academy of Medical Sciences. The authors declare that there are no conflicts of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Purpose: This study aimed to identify the risk factors for meniscal repair failure following concurrent primary anterior cruciate ligament (ACL) reconstruction., Methods: Prospective data recorded by the New Zealand ACL Registry and the Accident Compensation Corporation were reviewed. Meniscal repairs performed during concurrent primary ACL reconstruction were included. Repair failure was defined as a subsequent reoperation involving meniscectomy of the repaired meniscus. Multivariate survival analysis was performed to identify the risk factors for failure., Results: A total of 3,024 meniscal repairs were analysed with an overall failure rate of 6.6% (n = 201) at a mean follow-up of 2.9 years (SD 1.5). The risk of medial meniscal repair failure was higher with hamstring tendon autografts (adjusted HR [aHR] = 2.20, 95% CI 1.36-3.56, p = 0.001), patients aged 21-30 years (aHR = 1.60, 95% CI 1.30-2.48, p = 0.037) and in patients with cartilage injury in the medial compartment (aHR = 1.75, 95% CI 1.23-2.48, p = 0.002). The risk of lateral meniscal repair failure was higher in patients aged ≤ 20 years (aHR = 2.79, 95% CI 1.17-6.67, p = 0.021), when the procedure was performed by a low case volume surgeon (aHR = 1.84, 95% CI 1.08-3.13, p = 0.026) and when a transtibial technique was used to drill the femoral graft tunnel (aHR = 2.30, 95% CI 1.03-5.15, p = 0.042)., Conclusion: The use of a hamstring tendon autograft, younger age and the presence of medial compartment cartilage injury are risk factors for medial meniscal repair failure, whereas younger age, low surgeon volume and a transtibial drilling technique are risk factors for lateral meniscal repair failure., Level of Evidence: Level II., (© 2023. The Author(s).)

The objective of this study was to compare rates of anterior cruciate ligament (ACL) failure among adolescent patients to evaluate patella alta as a high-risk variable. Demographic and surgical data were retrospectively queried for patients ≤18 years of age with primary ACL reconstruction performed at a single academic center between 2011 and 2016 and minimum of 2-year clinical surveillance. Patellar height indices, including Caton-Deschamps index (CDI) and Insall-Salvati index (ISI), were retrospectively calculated from preoperative imaging to assess the presence of patella alta. Failure was defined as (1) ACL graft rerupture, (2) Lachman's grade 2 + , (3) presence of pivot shift, and (4) side-to-side difference of 3 mm on KT-1000 arthrometer. A total of 184 patients (84 females and 100 males) and 192 knees were identified, with an average age of 16.2 ± 1.8 years. Of these, 30 (15.63%) experienced ACL failure. Male sex was the only significant risk factor for rerupture ( p  = 0.026). The mean CDI was 1.06 ± 0.17 and mean ISI was 1.04 ± 0.15. Of the 49 knees that met criteria for patella alta on radiographic evaluation, rerupture occurred in seven (14.29%). Patella alta was not a significant risk factor for ACL failure among adolescent patients ( p  = 0.359 and 0.277). Only male sex was associated with increased rates of ACL failure. Age, graft selection technique, fixation construct, and presence of patella alta were not risk factors for reinjury. This study is a therapeutic case series and reflects level of evidence IV., Competing Interests: None declared., (Thieme. All rights reserved.)

Purpose: To systematically review the current literature regarding the indications, techniques, and outcomes after 2-stage revision anterior cruciate ligament reconstruction (ACLR)., Methods: A literature search was performed using SCOPUS, PubMed, Medline, and the Cochrane Central Register for Controlled Trials according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. Inclusion criteria was limited to Level I-IV human studies reporting on indications, surgical techniques, imaging, and/or clinical outcomes of 2-stage revision ACLR., Results: Thirteen studies with 355 patients treated with 2-stage revision ACLR were identified. The most commonly reported indications were tunnel malposition and tunnel widening, with knee instability being the most common symptomatic indication. Tunnel diameter threshold for 2-stage reconstruction ranged from 10 to 14 mm. The most common grafts used for primary ACLR were bone-patellar tendon-bone (BPTB) autograft, hamstring graft, and LARS (polyethylene terephthalate) synthetic graft. The time elapsed from primary ACLR to the first stage surgery ranged from 1.7 years to 9.7 years, whereas the time elapsed between the first and second stage ranged from 21 weeks to 13.6 months. Six different bone grafting options were reported, with the most common being iliac crest autograft, allograft bone dowels, and allograft bone chips. During definitive reconstruction, hamstring autograft and BPTB autograft were the most commonly used grafts. Studies reporting patient-reported outcome measures showed improvement from preoperative to postoperative levels in Lysholm, Tegner, and objective International Knee and Documentation Committee scores., Conclusions: Tunnel malpositioning and widening remain the most common indications for 2-stage revision ACLR. Bone grafting is commonly reported using iliac crest autograft and allograft bone chips and dowels, whereas hamstring autograft and BPTB autograft were the most used grafts during the second-stage definitive reconstruction. Studies showed improvements from preoperative to postoperative levels in commonly used patient reported outcomes measures., Level of Evidence: Level IV, systematic review of Level I, III, and IV studies., (Copyright © 2023. Published by Elsevier Inc.)

This study compared the clinical outcomes of patients treated with described "modified all-inside" anterior cruciate ligament reconstruction (ACLR) technique with those of patients treated with suspensory femoral fixation and a bioabsorbable tibial interference screw with the ACLR technique. From 2017 to 2019, 98 patients who underwent ACLR surgery by two surgeons using either of the techniques were included in this study. Patients in group 1 were treated with the "modified all-inside" ACLR technique. In this technique, only the semitendinosus tendon was harvested as a four-strand graft and fixed to the tibia and femur with suspensory buttons. Patients in group 2 were treated with suspensory femoral fixation and a bioabsorbable tibial interference screw ACL reconstruction technique. Patients' functional outcomes were evaluated by the Lysholm score, Tegner activity scale, and International Knee Documentation Committee (IKDC) subjective score. Postoperative knee stability of the patients was evaluated using the Lachman test and the pivot-shift test. The mean ages of the patients were 31.1 (16-55) and 28.7 (18-48) years in groups 1 and 2, respectively. The average follow-up durations were 26 (20-30) and 25.9 (22-30) months for both groups. There was no significant difference between the preoperative and postoperative Lysholm's score, Tegner's activity score, and IKDC subjective score in groups 1 and 2. There were no major complications or reruptures in either group. ACLR incorporating the "modified all-inside" ACLR technique obtained significant clinical outcomes compared to ACLR with a suspensory femoral fixation and a bioabsorbable tibial interference screw., Competing Interests: None declared., (Thieme. All rights reserved.)

Purpose: To determine what knee morphological factors are associated with the development of mucoid degeneration of the anterior cruciate ligament (ACL)., Methods: Three databases MEDLINE, PubMed and EMBASE were searched from inception to January 29th, 2023 for literature outlining knee morphological factors that potentially lead to the development of mucoid degeneration of the ACL. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on receiver operating characteristic (ROC) curve parameters such as area under the curve (AUC), sensitivity and specificity, odds ratios, as well as p values for comparisons of values between mucoid degeneration of the ACL and control patients were recorded. The Methodological Index for Non-Randomized Studies (MINORS) score was used for all studies to perform a quality assessment of included studies., Results: A total of 7 studies comprising 1326 patients (1330 knees) were included in this review. Four studies reported a significant association between increasing posterior tibial slope angles and mucoid degeneration of the ACL presence, with one study specifying that posterolateral tibial slope had a greater association than posteromedial tibial slope. Two studies reported a significant association between lower notch width index values and mucoid degeneration of the ACL presence. One study found that the presence of trochlear dysplasia was correlated with mucoid degeneration of the ACL and two studies found that increased tibial tuberosity-trochlear groove distance (TT-TG) was associated with mucoid degeneration of the ACL., Conclusion: Increased posterior tibial slope, decreased notch width index, and elevated TT-TG and trochlear dysplasia were associated with the presence of mucoid degeneration of the ACL. Information from this review can aid surgeons in understanding what morphological features predispose their patients to the development of mucoid degeneration of the ACL. Identifying what features predispose patients to mucoid degeneration of the ACL can help determine if regular screening or preventative strategies are necessary., Level of Evidence: Level III., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: Anterior cruciate ligament tears and anterior cruciate ligament reconstruction (ACLR) are common in young athletes. The modifiable and non-modifiable factors contributing to ACLR failure and reoperation are incompletely understood. The purpose of this study was to determine ACLR failure rates in a physically high-demand population and identify the patient-specific risk factors, including prolonged time between diagnosis and surgical correction, that portend failure., Methods: A consecutive series of military service members with ACLR with and without concomitant procedures (meniscus [M] and/or cartilage [C]) done at military facilities between 2008 and 2011 was completed via the Military Health System Data Repository. This was a consecutive series of patients without a history of knee surgery for two years prior to the primary ACLR. Kaplan-Meier survival curves were estimated and evaluated with Wilcoxon test. Cox proportional hazard models calculated hazard ratios (HR) with 95% confidence intervals (95% CI) to identify demographic and surgical factors that influenced ACLR failure., Results: Of the 2735 primary ACLRs included in the study, 484/2,735 (18%) experienced ACLR failure within four years, including (261/2,735) (10%) undergoing revision ACLR and (224/2,735) (8%) due to medical separation. The factors that increased failure include Army Service (HR 2.19, 95% CI 1.67, 2.87), > 180 days from injury to ACLR (HR 1.550, 95% CI 1.157, 2.076), tobacco use (HR 1.429 95% CI 1.174, 1.738), and younger patient age (HR 1.024, 95% CI 1.004, 1.044)., Conclusion: The overall clinical failure rate of service members with ACLR is 17.7% with minimum four-year follow-up, where more patients are likely to fail due to revision surgery than medical separation. The cumulative probability of survival at 4 years was 78.5%. Smoking cessation and treating ACLR patients promptly are modifiable risk factors impacting either graft failure or medical separation., Level of Evidence: Level III., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Purpose: The purpose of this study was to evaluate whether harvesting a second graft from the ipsilateral extensor mechanism adversely affects clinical outcomes in revision anterior cruciate ligament (ACL) reconstruction., Methods: A retrospective review of 34 patients undergoing revision anterior cruciate ligament (ACL) reconstruction with either quadriceps tendon (QT) autograft or bone-tendon-bone (BTB) autograft was conducted. Patients with two grafts (BTB+QT) from the extensor mechanism were matched based on age, laterality, and sex to patients who had primary reconstruction with hamstring (HS) autograft followed by revision with either BTB or QT autograft (HS+QT/BTB). Return of quadriceps function was assessed with time to return to jogging in a standardized rehab protocol or time to regain 80% quadriceps strength. Secondary outcomes included International Knee Documentation Committee (IKDC) and Marx scores at 12-month follow-up and return to sport., Results: There were no significant differences in return to jogging or 80% quadriceps strength (HS 149.5 ± 38.2 days, BTB+QT 131.7 ± 40.1 days, n.s.), number able to return to sport (HS 62%, BTB+QT 93%, n.s.), months to return to sport (HS 10.6 ± 1.4, BTB+QT 10.5 ± 2.3, n.s.), return to pre-injury level of competition (HS 62%, BTB+QT 73%, n.s.), or IKDC (HS 77.2 ± 16.4, BTB+QT 74.8 ± 23.9, n.s.) and Marx scores (HS 9.2 ± 5.3, BTB+QT 8.0 ± 3.7, n.s.) at one-year follow-up., Conclusion: The main finding of the present study was that outcomes for patients who underwent revision ACL reconstruction with a second extensor mechanism autograft were comparable to those seen for patients who underwent revision ACL reconstruction with extensor mechanism autograft after primary ACL reconstruction with hamstring autograft. By better understanding the consequences of harvesting a second graft from the extensor mechanism, surgeons can better decide what graft to use in revision ACL reconstruction., Level of Evidence: Level III., (© 2022. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Background: Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population., Objective: To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)]., Study Design: Cross-sectional., Level of Evidence: Level 2., Methods: Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures., Results: Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB ( P = 0.045)., Conclusion: After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure., Clinical Relevance: Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure.

Purpose: To gain a deeper understanding of patients' experiences over 5 years after anterior cruciate ligament (ACL) reconstruction., Methods: Seventeen semi-structured interviews were performed with patients treated with ACL reconstruction at least 5 years earlier without a second knee injury. Interviews were transcribed and analyzed using qualitative content analysis according to methods described by Graneheim and Lundman., Results: Patients' long-term experiences after an ACL reconstruction were summarized as: "to cope or not to cope, that is the question", and five main categories: (1) Adapting life after knee symptom: the past will not come back; (2) An arduous and demanding rehabilitation: sailing against the wind; (3) Accepting what cannot be changed: biting the bullet; (4) Being satisfied with results: end of a chapter; (5) Apprehensively peregrinating on an unknown road., Conclusions: More than 5 years after ACL reconstruction, patients can experience full symptom resolution and the ACL injury process as positive, or experience persistent symptoms and are forced to accept negative life-changing choices due to the injury., Level of Evidence: IV., (© 2022. The Author(s).)

We hypothesize that larger prior tunnel size is associated with an increased risk of failure of single-stage revision anterior cruciate ligament reconstruction (ACLR) as defined by the performance of a re-revision (third) ACLR on the index knee. Retrospective review identified 244 patients who underwent single-stage revision ACLR at a single center with available preoperative radiographs. Patient and surgical factors were extracted by chart review. The maximum diameter of the tibial tunnel was measured on lateral radiographs and the maximum diameter of the femoral tunnel was measured on anteroposterior radiographs. Record review and follow-up phone calls were used to identify failure of the revision surgery as defined by re-revision ACLR on the index knee. One hundred and seventy-one patients (70%) were reviewed with a mean of 3.9 years follow-up. Overall, 23 patients (13.4%) underwent re-revision surgery. Mean tibial tunnel size was 12.6 ± 2.8 mm (range: 5.7-26.9 mm) and mean femoral tunnel size was 11.7 ± 2.8 mm (range: 6.0-23.0 mm). Re-revision risk increased with tibial tunnel size. Tibial tunnels 11 mm and under had a re-revision risk of 4.2%, while tunnels > 11 mm had a risk of 17.1% (relative risk: 4.1, p  = 0.025). No significant association between femoral tunnel size and re-revision risk was noted. Patients with prior tibial tunnels > 11mm in diameter at revision surgery had significantly increased risk of re-revision ACLR. Further studies are needed to explore the relationship between prior tunnel size and outcomes of revision ACLR., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Several tibiofemoral anatomic features have been repeatedly associated with increased anterior cruciate ligament (ACL) injury risk. Previous studies have highlighted age and sex differences among these anatomic risk factors, but little is known about the normal and pathologic development of these differences during skeletal maturation., Purpose: To investigate differences in anatomic risk factors at various stages of skeletal maturation between ACL-injured knees and matched controls., Study Design: Cross-sectional study; Level of evidence, 3., Methods: After institutional review board approval, magnetic resonance imaging scans from 213 unique ACL-injured knees (age, 7-18 years, 48% female) and 239 unique asymptomatic ACL-intact knees (age, 7-18 years, 50% female) were used to measure femoral notch width, posterior slope of the lateral and medial tibial plateau, medial and lateral tibial spinal height (MTSH, LTSH), medial tibial depth, and posterior lateral meniscus-bone angle. Linear regression was performed to assess change in quantified anatomic indices with age for male and female patients in the ACL-injured cohort. Two-way analysis of variance with Holm-Sidak post hoc testing was performed to compare anatomic indices between ACL-injured knees and ACL-intact controls in each age group., Results: In the ACL-injured cohort, notch width, notch width index and medial tibial depth increased with age ( R 2 > 0.1; P < .001) in both sexes. MTSH and LTSH increased with age only in boys ( R 2 ≥ 0.09; P ≤ .001), whereas meniscus-bone angle decreased with age only in girls ( R 2 = 0.13; P < .001). There were no other age differences in quantified anatomic indices. Patients with ACL injury consistently had a significantly higher lateral tibial slope ( P < .01) and smaller LTSH ( P < .001) as compared with ACL-intact controls across all age groups and sexes. When compared with age- and sex-matched ACL-intact controls, ACL-injured knees had a smaller notch width (boys, 7-18 years; girls, 7-14 years; P < .05), larger medial tibial slope (boys and girls, 15-18 years; P < .01), smaller MTSH (boys, 7-14 years; girls, 11-14 years; P < .05), and larger meniscus-bone angle (girls, 7-10 years; P = .050)., Conclusion: The consistent morphologic differences throughout skeletal growth and maturation suggest a developmental role in high-risk knee morphology. The observed high-risk knee morphology at an earlier age preliminarily suggests the potential of knee anatomy measurements in identifying those with a predisposition toward ACL injury.

Background: An increased posterior tibial slope (PTS) is a risk factor for primary anterior cruciate ligament (ACL) tears and graft failure, but the PTS has not been well-defined in those who have experienced bilateral ACL injuries., Purpose: The primary aim was to compare the PTS, as well as the rate of an elevated PTS (>12° on lateral radiography; >7° on magnetic resonance imaging [MRI]), between patients who have undergone bilateral ACL reconstruction (ACLR) versus unilateral ACLR. A secondary purpose was to examine whether these associations remained consistent on both plain radiography and MRI., Study Design: Cross-sectional study; Level of evidence, 3., Methods: We retrospectively identified patients who underwent primary ACLR at our institution from the years 2012 to 2020. Patients who underwent nonsimultaneous bilateral ACLR (n = 53) were matched to those who underwent unilateral ACLR (n = 53) by age, sex, and body mass index. Exclusion criteria were rotated lateral radiographs, MRI scans of inadequate quality, and concomitant ligament injuries or fractures. Those who had undergone unilateral ACLR with <5-year follow-up were further excluded. There were 3 blinded readers who measured the PTS on lateral radiographs, while the medial PTS (MPTS) and lateral PTS (LPTS) were measured on MRI scans. Bivariate regression was performed to determine the correlation between radiographic and MRI measurements., Results: The PTS on radiography (11.26° vs 10.13°, respectively; P = .044) and the LPTS on MRI (7.32° vs 6.08°, respectively; P = .012) in the bilateral ACLR group were significantly greater than those in the unilateral ACLR group but not the MPTS on MRI (4.55° vs 4.17°, respectively; P = .590). The percentage of patients in the bilateral group with a radiographic PTS >12° was 41.0% compared with 13.2% in the unilateral group ( P = .012). The bilateral group had a significantly higher rate of an LPTS >7° compared with the unilateral group (53.8% vs 32.1%, respectively; P = .016) but not for an MPTS >7° ( P = .190). On MRI, the LPTS (6.90°± 2.73°) was significantly greater than the MPTS (4.41°± 2.92°) ( P < .001). There was a weak correlation between MPTS and radiographic PTS measurements ( R = 0.24; P = .021), but LPTS and radiographic PTS measurements were not significantly correlated ( R = 0.03; P = .810)., Conclusion: Patients who underwent bilateral ACLR had a significantly greater PTS on radiography and a significantly greater LPTS on MRI compared with those who underwent unilateral ACLR. The rate of a radiographic PTS >12° was 2.4 times greater among patients undergoing bilateral ACLR compared with those undergoing unilateral ACLR. PTS measurements on radiography demonstrated a weak to negligible correlation with PTS measurements on MRI, suggesting that future normative PTS values should be reported specific to the imaging modality., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: M.J.A. has received publishing royalties from Springer; research support from Orcosa; and consulting fees from Arthrex, JRF Ortho, and Mitek. E.J.S. has received publishing royalties from Jaypee Brothers Medical Publishers and Springer; has received research support from CartiHeal and Fidia Pharma; has received consulting fees from Arthrex, JRF Ortho, Smith & Nephew, Organogenesis, Subchondral Solutions, Vericel, and Flexion Therapeutics; and holds stock options in BetterPT. L.M.J. has received publishing royalties from Wolters Kluwer Health–Lippincott Williams & Wilkins and research support from Mitek, Smith & Nephew, and Arthrex. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Purpose: To evaluate the clinical outcomes of anterior cruciate ligament reconstruction (ACLR) with meniscal allograft transplantation (MAT) through a systematic review of current available evidence., Methods: A systematic database search of PubMed, Embase, Web of Science, and CINAHL was performed from inception up to December 7, 2021, in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses. Follow-up studies (inception cohort studies/nonrandomized controlled trials/retrospective cohort studies) and case series that had more than 10 people published in English and involved patients who underwent a combination of ACLR and MAT were included. The quality of these studies was appraised using the Cochrane Risk Of Bias In Non-randomized Studies of Interventions tool. Systematic review of International Knee Documentation Committee (IKDC), Lysholm, and Tegner activity scores were conducted., Results: Seven studies involving 363 patients were included. The average mean follow-up time was 4.08 years, ranging from 1.75 to 14 years. All studies used the Lysholm Knee Scoring system to report clinical outcomes, whereas 2 studies and 4 studies used the IKDC Questionnaire and Tegner activity scale respectively to measure clinical outcomes postoperatively. Comparing postoperative with preoperative scores, we found an improvement above the minimal clinically important difference for the Lysholm (mean difference [MD] range 16.00-26.10) and Tegner activity scores (MD range 1.50-1.90). All but one study reported an increase above the minimal clinically important difference for IKDC scores postoperatively (MD range 5.60-23.00)., Conclusions: Combined MAT and ACLR have good 2- to 14-year clinical outcomes postoperatively and is an optimal procedure for patients with concurrent ACL injuries with irreparable meniscus injuries., Level of Evidence: IV, systematic review and/or meta-analysis of studies with Levels I to IV., (Copyright © 2022 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: Anterior cruciate ligament (ACL) injuries in adults are frequently accompanied by meniscal and articular cartilage damage. However, little is known regarding the association, if any, between physical maturity, hypermobility, or bone bruising and these associated injuries in skeletally immature patients with ACL tears., Purpose: To determine if physical maturity, hypermobility, and/or bone bruising is associated with concomitant meniscal and articular cartilage injury in skeletally immature patients with ACL tears., Study Design: Cohort study; Level of evidence, 2., Methods: At 10 institutions in the United States, consecutive skeletally immature patients with complete ACL tears were enrolled between January 2016 and June 2020. Univariable and multivariable logistic regression analysis was used to assess the effect of variables on the likelihood of articular cartilage and meniscal injury., Results: A total of 748 patients were analyzed. Of these, 85 patients (11.4%) had articular cartilage injuries. These patients had a higher bone age (13.9 vs 13.1 years; P = .001), a higher Tanner stage ( P = .009), and increased height (162.9 vs 159.9 cm; P = .03) and were heavier (57.8 vs 54.0 kg; P = .02). For each additional Tanner stage, the odds of articular cartilage injury increased approximately 1.6 times ( P < .001). Of the total patients, 423 (56.6%) had meniscal tears. Those with meniscal tears were older (12.6 vs 12.0 years; P < .001), had a higher bone age (13.5 vs 12.8 years; P < .001), had a higher Tanner stage ( P = .002), had increased height (162.2 vs 157.6 cm; P < .001), and were heavier (56.6 vs 51.6 kg; P < .001). For each additional Tanner stage, the odds of a meniscal tear increased approximately 1.3 times ( P < .001). No association was detected between hypermobility or bone bruising and the likelihood of articular cartilage or meniscal injury. Multivariable regression revealed that increasing Tanner stage was associated with an increasing risk of articular cartilage injury, while weight was associated with an increasing risk of meniscal injury., Conclusion: Increasing physical maturity is associated with increased risks of concomitant articular cartilage and meniscal injury in skeletally immature patients with ACL tears. Hypermobility and bone bruising are not associated with articular cartilage or meniscal injury, suggesting that physical maturity, rather than ligamentous laxity, is the primary risk factor for associated injuries in skeletally immature patients with an ACL tear.

Background: A comprehensive understanding of the intrinsic risk factors for anterior cruciate ligament (ACL) disruption is important for identifying individuals at increased risk for suffering this trauma and developing interventions to mitigate risk., Hypothesis: A variety of risk factors predispose athletes to first-time, noncontact ACL injury and some of these differ between male and female athletes., Study Design: Prospective cohort study with nested case-control sampling., Level of Evidence: Level 2., Methods: Sport teams at 28 high schools and 8 colleges were monitored prospectively over 4 years, and 109 of 130 athletes who suffered their first noncontact ACL injury participated in the study. At the time of injury, matched control subjects were randomly selected from among the case's teammates and a total of 227 athletes participated. Demographic characteristics, joint laxity, lower extremity alignment, strength, and personality characteristics were measured. The association of each risk factor with injury risk was assessed by conditional logistic regression., Results: The risk factors that were associated with ACL injury in both male and female athletes included having a parent with prior ACL injury and increases of the following variables: body weight, anterior displacement of the tibia relative to the femur, genu recurvatum, and generalized joint laxity. Risk factors that are unique to female athletes included increased body mass index, increased trunk flexion strength, and prior non-ACL knee injury. The risk factors specific to male athletes were decreased standing quadriceps angle, decreased hip adduction strength, and chronic disease., Conclusion: A diverse set of risk factors predispose both male and female athletes to ACL injury, whereas others appear to be sex-specific., Clinical Relevance: Different approaches for assessing risk and preventing ACL injury are needed for male and female athletes. In addition, personalized prevention strategies may be needed to target the specific characteristics that place an individual at increased risk of suffering this trauma.

Purpose: Anterior cruciate ligament (ACL) injury rate is low among children, but increases during adolescence, especially in girls. Increases in the knee valgus moment within 70 ms of contact with the ground (KFM 0-70 ) may explain the sex-specific increase in the risk of ACL injury. The purpose of the study was to investigate sex-dependent changes in the KFM 0-70 from pre-adolescence to adolescence during a cutting maneuver (CM)., Methods: Kinematic and kinetic data during the CM task, performed before and after physical exertion, were recorded using a motion capture system and a force plate. A total of 293 team handball and soccer players, aged 9-12 years, were recruited. A number of those who continued sports participation (n = 103) returned five years later to repeat the test procedure. Three mixed-model analysis of variance (ANOVA) for repeated measures tests were used to determine the effects of sex and age period on the KFM 0-70 (1: with no adjustment, 2: adjusted for repeated measurements, and 3: additionally adjusted with hip and knee joint frontal plane kinematics)., Results: Boys had significantly higher KFM 0-70 than girls at both age periods (p < 0.01 for all models). Girls, not boys, demonstrated significantly increased KFM 0-70 from pre-adolescence to adolescence. Importantly, this was fully explained by kinematic variables., Conclusion: Although the marked increase in KFM 0-70 seen in girls may play a role in their risk of ACL rupture, the higher values demonstrated by boys during CM reflect the complexity of multifactorial biomechanical risk factor analysis. The role of kinematics in mediating the KFM 0-70 provides means for modification of this risk factor, but as boys had higher joint moments, continued investigation into sex-dependent biomechanical risk factors is warranted., Level of Evidence: II., (© 2023. The Author(s).)

Background: Knee kinematic parameters during a drop vertical jump (DVJ) have been demonstrated to be associated with increased risk of noncontact anterior cruciate ligament (ACL) injury. However, standard motion analysis systems are not practical for routine screening. Affordable and practical motion sensor alternatives exist but require further validation in the context of ACL injury risk assessment., Purpose/hypothesis: To prospectively study DVJ parameters as predictors of noncontact ACL injury in collegiate athletes using an affordable motion capture system (Kinect; Microsoft). We hypothesized that athletes who sustained noncontact ACL injury would have larger initial and peak contact coronal abduction angles and smaller peak flexion angles at the knee during a DVJ., Study Design: Case-control study; Level of evidence, 3., Methods: 102 participants were prospectively recruited from a collegiate varsity sports program. A total of 101 of the 102 athletes (99%) were followed for an entire season for noncontact ACL injury. Each athlete performed 3 DVJs, and the data were recorded using the motion capture system. Initial coronal, peak coronal, and peak sagittal angles of the knee were identified by our software., Results: Five of the 101 athletes sustained a noncontact ACL injury. Peak coronal angles were significantly greater and peak sagittal flexion angles were significantly smaller in ACL-injured athletes ( P = .049, P = .049, respectively). Receiver operating characteristic (ROC) analysis demonstrated an area under the curve of 0.88, 0.92, and 0.90 for initial coronal, peak coronal, and peak sagittal angle, respectively. An initial coronal angle cutoff of 2.96° demonstrated 80% sensitivity and 72% specificity, a peak coronal angle cutoff of 6.16° demonstrated 80% sensitivity and 72% specificity, and a peak sagittal flexion cutoff of 93.82° demonstrated 80% sensitivity and 74% specificity on the study cohort., Conclusion: Increased peak coronal angle and decreased peak sagittal angle during a DVJ were significantly associated with increased risk for noncontact ACL injury. Based on ROC analysis, initial coronal angle showed good prognostic ability, whereas peak coronal angle and peak sagittal flexion provided excellent prognostic ability. Affordable motion capture systems show promise as cost-effective and practical options for large-scale ACL injury risk screening.

Background: Surgical reconstruction of ACL injuries is a common strategy but superiority over conservative treatment has not been established. The aim was to perform a systematic review and meta-analysis comparing outcomes between operative and non-operative treatment of ACL injuries., Methods: Systematic review of Medline, Embase, Scopus, and Google Scholar, including all level 1-3 studies from 2000 to 2021. Patient reported outcome scores and objective measures for knee stability were included. Risk of bias was assessed using the Cochrane Collaboration's tools. GRADE was used to assess the quality of the body of evidence. Heterogeneity was assessed using χ2 and I 2 statistics., Results: Twelve studies were included in the analysis. All studies had a high risk of bias and were of low quality. The pooled estimates for IKDC (p = 0.040) favored surgical treatment. There were significant differences for activities of daily living (p = 0.0001) in favor of conservative treatment. There were significant differences for knee stability (p = 0.016) in favor of surgical treatment. The risk of osteoarthritis was not significantly different between the two treatment modalities (p = 0.219). Patients undergoing surgery had a 57% higher risk of osteoarthritis., Conclusion: ACL reconstruction results in a significantly more stable knee with superior clinical and functional outcomes. However, these advantages over conservative treatment were not observed for routine activities of daily living, and subjective patient perceived outcomes favor nonsurgical treatment. Surgical treatment did not reduce the risk of later developing osteoarthritis. Regardless, due to low study quality and high risk of bias, these findings must be interpreted with caution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The usage of electric scooters has been popular because it is a cheap and fast transportation method. Its use has increased in recent years because public transportation is less preferred during the covid-19 pandemic and in parallel, the publications reporting e-scooter accidents are increasing. There is no article examining the relationship between e-scooter and anterior cruciate ligament (ACL) injury in current literature. We aim to examine the relationship between e-scooter accidents and ACL injury incidence. Patients over the age of 18 years who applied to our orthopedics outpatient clinic with the diagnosis of ACL injury between January 2019- June 2021 were evaluated. 80 e-scooter accidents resulting with ACL tears were reviewed. The electronic medical records of the patients were reviewed retrospectively. Information about the age, gender, trauma history of the patients, and type of trauma was obtained. Fifty-eight patients had a history of falling while stopping the scooter, and 22 patients had a history of falling after hitting something. Anterior cruciate ligament reconstruction was performed with hamstring tendon grafts in 62(77,5%) of the patients included in the study. 18 (22,5%) patients were followed up with functional physical therapy exercises because they did not want to be operated on. Various bone or soft tissue injuries while using e-scooters have been reported in the literature until now. ACL injury is also seen quite frequently after these traumas, and necessary information and warnings should be given to the users to prevent ACL injuries.

Background: Cyclops lesions are a known complication following anterior cruciate ligament reconstruction (ACLR) with a described incidence between 1.9% to 10.9%. The objective of this study was to identify the incidence, timing, and variables that correlated with development of a cyclops lesion, and if objective functional testing differed between patients with and without cyclops lesions., Methods: 313 consecutive patients who underwent ACLR and participated in Lower-Extremity Assessment Protocol (LEAP) testing at a single, academic institution were analyzed. Retrospective chart review was performed to identify patient demographic factors, medical comorbidities, and potential peri-operative risk factors. Postoperative functional outcome metrics and patient reported outcomes were collected per the institution's LEAP testing protocol. Binary logistic regression was utilized to identify risk factors for cyclops lesions. Objective functional outcomes and patient reported outcomes were compared between patients with and without cyclops lesions., Results: 23/313 (7.35%) patients developed a cyclops lesion following ACLR, of which 17 (73.91%) were found to be symptomatic. Concomitant meniscal repair correlated with an increased likelihood of developing a cyclops lesion (p = 0.040); no other risk factors significantly differed between cohorts. There were no clinically relevant extension deficits or differences in objective functional performance measures at six months post-operatively between study cohorts., Conclusions: Concomitant meniscal repair may be associated with the development of cyclops lesions due to restrictive postoperative range of motion protocols; however no other pre- or intra-operative factors demonstrated significant correlation. Presence of a cyclops lesion should be considered with late loss of knee extension after ACLR., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The utility of nonsurgical, mechanical compression-based joint injury models to study osteoarthritis pathogenesis and treatments is increasing. Joint injury may be induced via cyclic compression loading or acute overloading to induce anterior cruciate ligament rupture. Models utilizing mechanical testing systems are highly repeatable, require little expertise, and result in a predictable onset of osteoarthritis-like pathology on a rapidly progressing timeline. In this chapter, we describe the procedures and equipment needed to perform mechanical compression-induced initiation of osteoarthritis in mice and rats., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To analyze the MRI features, in particular bone bruises pattern, of Anterior Cruciate Ligament (ACL) injured footballers, and to correlate them with the characteristics of injury mechanism and situation obtained from direct video footage., Methods: Nineteen professional football (soccer) players that sustained ACL injury while playing during an official match of First League Championship were included in the study. The video of injury was obtained from the Television broadcast. Knee Magnetic Resonance (MRI) was obtained within 7 days from the injury. BB and meniscal lesions were analyzed on MRI, while a video-analysis of mechanisms of ACL injury and injury dynamic were assessed from the videos., Results: The most commonly involved Bone Bruise areas in the knee were the Posterior Lateral Tibial Plateau (LTp) in 16 cases (84%) and the Central Lateral Femoral Condyle (LFc) in 11 cases (58%). Three patients (16%) had bone bruise in the Posterior Medial Tibial Plateau (MTp) while none (0%) had bone bruise in the Medial Femoral Condyle. Based on the bone bruise pattern, 11 (58%) had simultaneous LFc and LTp and were defined "Typical" while 8 (42%) had other locations or no bone bruise and were defined "Atypical". 9 out of 11 injuries (82%) of athletes with "Typical" pattern occurred with a "Pivoting" action", in contrast to only 1 case (12%) in those with "Atypical" bone bruise pattern (p = 0.0055). The most common situational mechanism pattern on video analysis was "pressing" (n = 7) accounting for the 47% of the "indirect" ACL injuries. In terms of movement pattern, ten injuries (52%) occurred during a "Pivoting" movement (7 pressing, 1 dribbling, 1 tackled, 1 goalkeeping), whereas the remaining were classified as "Planting" in four cases, "Direct Blow" in four cases and "Landing"., Conclusion: A well-defined and consistent bone bruise pattern involving the posterior tibial plateau and central femoral condyle of lateral compartment is present in footballers that sustained non-contact and indirect ACL injuries during pivoting with sudden change of direction/deceleration, while heterogeneous patterns were present in those with direct contact or injury mechanisms involving high horizontal velocity., Level of Evidence: Level IV., (© 2022. The Author(s).)

Objective: The SARS-COV2 pandemic led to massive disruptions of care for orthopedic patients. Although many elective procedures were put on hold, a cohort of patients who underwent surgery prior to the outbreak of the pandemic were rendered unable to participate in standard post-operative care. The purpose of this study was to determine the methods of post-operative care in arthroscopic anterior cruciate ligament reconstruction patients who received care during an early height of the pandemic to those who received standard of care in the prior year. We aimed to correlate those results with 1-year clinical outcomes in the form of subjective surveys., Methods: Retrospective chart review was used to identify patients who underwent primary anterior cruciate ligament reconstruction in February and March of 2020 (case) and 2019 (control) at a single institution. Workman's compensation patients were excluded. Identified patients were asked to report post-operative care received, satisfaction with care, and complete the IKDC and Lysholm outcome measures. Surveys were conducted minimum 1-year post-operative., Results: 236 patients were identified, including 103 in 2020 and 133 in 2019. Follow-up data was collected for 73 patients (70.9%) in 2020 and 97 patients (72.9%) in 2019. Fifty-one COVID cohort patients (69.9%) had at least one clinical visit conducted via telehealth, compared to zero in the control. There were no differences in IKDC (82.8 ± 13.2 vs 85.0 ± 12.0, P = 0.29) and Lysholm (89.2 ± 11.3 vs 89.6 ± 10.8, P = 0.82) between groups. There were no differences in patient satisfaction with the care received (82.9 ± 22.4 vs 81.9 ± 21.8, P = 0.79)., Conclusion: Despite disruptions in care, anterior cruciate ligament reconstruction patients have excellent 1-year outcomes during the pandemic. Telehealth follow-up appointments may be appropriate for anterior cruciate ligament reconstruction patients beyond the pandemic and do not seem to adversely affect short-term patient reported outcome measures.

Purpose: To evaluate whether graft-type and tunnel location in ACL reconstruction impact patient-reported outcomes in individuals over the age of 45., Methods: From 2015 to 2018, patients over 45 years old undergoing primary ACL reconstruction without multi-ligamentous injuries were enrolled in an institutional registry. Baseline International Knee Documentation Committee (IKDC) subjective scores, Knee Injury and Osteoarthritis Outcome Scores (KOOS), Marx Activity Scale, and patient characteristics were collected. Follow-up occurred at a minimum of two years to obtain patient-reported outcomes., Results: Of the 51 patients who qualified for the study, 44 (86.3%) patients were available at a minimum of two years after surgery date (range 24-60 months). Average age at time of surgery of the available patients was 51.6 ± 4.87 (range 45-66). Between femoral tunnel drilling methods, there were no differences in the proportion of patients achieving clinically significant improvement or post-operative outcome scores. While patients who received patellar tendon autografts were more likely to achieve clinically significant improvement in the KOOS sports subscale, there were no other differences in outcomes measures between graft types. Two patients had a retear of their graft, and an additional five patients complained of subjective instability., Conclusions: In patients over the age of 45, neither the method used to create the femoral tunnel nor the graft type used in ACL reconstruction caused a significant difference in post-operative PROMs with a minimum of two years of follow-up., Level of Evidence: Therapeutic IV, Case Series., (© 2021. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Despite the restoration of the mechanical stability of the knee joint after ACL reconstruction (ACLR), patients often experience postoperative limitations. To our knowledge, there are no systematic reviews analyzing additional physiotherapy interventions implementing standard rehabilitation programs in the early postoperative phase after ACLR. The objective of this study was to analyze the additional physiotherapy interventions implemented in standard rehabilitation programs that improve early-stage ACLR rehabilitation. For this systematic review, we followed the PRISMA guidelines. In March 2022 we conducted a literature review using electronic databases. Primary outcomes were pain, edema, muscle strength, ROM, and knee function. The risk of bias and scientific quality of included studies were assessed with the RoB 2, ROBINS-I and PEDro scale. For the review, we included 10 studies that met the inclusion criteria (total n = 3271). The included studies evaluated the effectiveness of Kinesio Taping, Whole-body vibration, Local Vibration Training, Trigger Point Dry Needling, High Tone Power Therapy, alternating magnetic field, and App-Based Active Muscle Training Program. Most of the additional physiotherapy interventions improved pain, edema, ROM, knee muscle strength, or knee function in early-stage postoperative ACL rehabilitation. Except for one study, no adverse events occurred in the included studies, which demonstrates the safety of the discussed physiotherapy interventions. Further in-depth research is needed in this area.

Purpose: Contralateral graft harvest in primary ACL reconstruction is relatively uncommon and the long-term comparative of this approach relative to ipsilateral harvest has not been described. The purpose of this study was to evaluate ACL graft and contralateral rupture following ipsilateral or contralateral semitendinosus and gracilis (STG) graft harvest at follow-up of a minimum 10 years post-reconstruction in the treatment of a complete ACL tear., Methods: Patients from a previous randomized trial were evaluated. The primary outcome measures were ipsilateral and contralateral reinjury as well as the International Knee Documentation Committee (IKDC) knee assessment form, the ACL Quality of Life questionnaire (ACL-QoL) and the Tegner activity scale. Participants completed four different single-leg hop tests and concentric knee flexion and extension strength were assessed on an isokinetic dynamometer., Results: Of the original 100 patients, 50 patients (41.3 ± 9.5 years of age, 31 males, 19 females) reported on re-injury at 12.6 ± 1.4 years post-operative. Thirty-eight patients returned for full assessment and 12 responded by mail or phone survey. There were no differences between groups for graft rupture, contralateral injury, ACL-QoL score, IKDC categorization, or anterior tibial translation, though both groups experienced a reduction in the Tegner Activity Scale from their preinjury scores. There was no difference in knee flexor and extensor isokinetic concentric strength, or single leg hop test performance. Knee flexor strength limb symmetry index was reduced when measured in the supine relative to the seated position in both groups, indicating persistent deficits in knee flexor strength when measured in the supine position., Conclusion: Contralateral hamstring harvest does not put patients at an increased risk of a contralateral ACL tear and long-term outcomes of ACL reconstruction do not differ based on the side of graft harvest. Contralateral STG harvest may provide a safe alternative surgical option for select patients., Level of Evidence: Level II., (© 2022. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Introduction: In this review paper, graft failure rates of different graft types (hamstring tendon autografts, bone-patellar tendon-bone autografts, quadriceps tendon autografts and diverse allografts) that are used for surgical reconstruction of the anterior cruciate ligament are compared and statistically analysed., Methods: Literature search was conducted in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria. A total of 194 studies, which reported graft failure rates of at least one of the anterior cruciate ligament reconstruction methods mentioned above, were included in this systematic review. To be able to compare studies with different follow-up periods, a yearly graft failure rate for each reconstruction group was calculated and then investigated for significant differences by using the Kruskal-Wallis test., Results: Overall, a total of 152,548 patients treated with an anterior cruciate ligament reconstruction were included in the calculations. Comparison of graft types showed that hamstring tendon autografts had a yearly graft failure rate of 1.70%, whereas the bone-patellar tendon-bone autograft group had 1.16%, the quadriceps tendon autograft group 0.72%, and the allografts 1.76%., Conclusion: The findings of this meta-data study indicate that reconstructing the anterior cruciate ligament using quadriceps tendon autografts, hamstring tendon autografts, patellar tendon autografts or allografts does not show significant differences in terms of graft failure rates., (© 2021. The Author(s).)