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Objective: To culturally adapt and validate the Italian version of the Shoulder Instability—Return to Sport after Injury (SI-RSI-I) scale. Methods: The SI-RSI-I was developed by adapting the Anterior Cruciate Ligament—Return to Sport Index—Italian version and replacing the term "knee" with "shoulder." Subsequently, it underwent validation following COSMIN recommendations. The study involved athletic participants who experienced SI. They completed the SI-RSI-I together with other measurement instruments: Western Ontario Shoulder Instability Index, Kerlan-Jobe Orthopedic Clinic Score, EuroQol-5D-5L, and Numeric Pain Rating Scale. The following psychometric properties were investigated: structural validity, internal consistency, test–retest reliability, measurement error, and construct validity. Results: The study included 101 participants (age mean [SD] 28.5 [7.4] y; 83 males, 18 females). The SI-RSI-I showed a single-factor structure, excellent internal consistency (α =.935), and excellent test–retest reliability (ICC =.926; 95% CI,.853–.964). The standard error of measurement was 6.1 points, and the minimal detectable change was 17.0 points. Furthermore, SI-RSI-I demonstrated moderate to strong correlations with all reference scales, confirming 8 out of 9 (88.0%) hypotheses, thus establishing satisfactory construct validity. Conclusion: The SI-RSI-I has demonstrated robust internal consistency, reliability, validity, and feasibility as a valuable scale for assessing psychological readiness to return to sport in Italian athletes with SI. [ABSTRACT FROM AUTHOR]

Context : In March 2020, public health concerns resulted in school closure throughout the United States . The prolonged sport cessation may affect knee injury risk in high school athletes. The purpose of this study was to describe and compare risk of knee injuries in high school athletes during 2019-2020 and 2020-2021 academic years, and stratify by gender, severity, mechanism of injury, injury type, and knee anatomic region . Design : Historical-prospective cohort study . Methods : This historical- prospective cohort study included 176 schools in 6 states matched by sport participation in control and COVID years from July 1, 2019 to June 30,2021. Injury rates per 1000 athletes per year were calculated with 95% confidence intervals. A negative binomial regression was performed to assess potential differences in knee injuries between academic years . Results: 94, 847 and 72,521 high school athletes participated in the 2019-2020(19-20) and 2020-2021 (20-21) seasons. Knee injury risk was higher in the 20-21 season (19-20: 28.89% [27.82-29.96-]; 20-21: 33.82% [32.50-35.14]). Risk increased for male athletes from 2019- 2020 to 2020-2021 (19-20: 29.42% [28.01-30.83]; 20-21 : 40.32% [38.89-41.75]). Female knee injury risk was similar between years (19-20: 25.78% [24.29-27.27]; 20-21: 26.03% [24.31-27.75]). Knee injuries increased by a ratio of 1.2 ([95% CI, 1.1- 1.3], P <.001) during 2020-2021. Conclusions,· Knee injury risk and relative risk increased among males in 2020-2021. Results indicate changes in knee injury risk following return from COVID shelter in place among high school athletes and implicate potential negative downstream effects of interrupted sports training and participation on high school injury risk. [ABSTRACT FROM AUTHOR]

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was.43 during the landing phase (P =.04) and with peak hip internal rotation was −.68 (P <.001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r =.40, P =.05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test. [ABSTRACT FROM AUTHOR]

The hamstring plays an important role in reducing loads born by the anterior cruciate ligament. As anterior cruciate ligament injuries occur rapidly after ground contact, how the hamstring is activated prior to landing can influence injury risk. The purpose was to determine sex-related differences in hamstring activation immediately before landing and the effect of fatigue on "preactivation." Twenty-four participants (13 males and 11 females, age = 24.3 [6.5] y, mass = 72.2 [19.3] kg, height = 169 [9.7] cm) participated in this study. Participants completed a drop-vertical jump protocol before and after a lower body fatigue protocol. Hamstring electromyography (EMG) amplitude at 5 periods prior to landing, peak vertical ground reactions forces (in newtons/body weight), rate of loading (in body weight/second), and landing error scoring system were measured. Females had higher EMG amplitude before and after fatigue (P <.024), with decreased EMG amplitude for both sexes after fatigue (P =.025). There was no change on vertical ground reaction force, rate of loading, or landing error scoring system. Males and females demonstrated similar landing performance before and after fatigue but have different hamstring neuromuscular coordination strategies. The acute reduction in hamstring EMG amplitude following fatigue may increase loading on the anterior cruciate ligament. [ABSTRACT FROM AUTHOR]

PurposeTo develop a 3D phase modulated UTE adiabatic T1ρ (PM-UTE-AdiabT1ρ ) sequence for whole knee joint mapping on a clinical 3 T scanner.MethodsThis new sequence includes six major features: (1) a magnetization reset module, (2) a train of adiabatic full passage pulses for spin locking, (3) a phase modulation scheme (i.e., RF cycling pair), (4) a fat saturation module, (5) a variable flip angle scheme, and (6) a 3D UTE Cones sequence for data acquisition. A simple exponential fitting was used for T1ρ quantification. Phantom studies were performed to investigate PM-UTE-AdiabT1ρ 's sensitivity to compositional changes and reproducibility as well as its correlation with continuous wave-T1ρ measurement. The PM-UTE-AdiabT1ρ technique was then applied to five ex vivo and five in vivo normal knees to measure T1ρ values of femoral cartilage, meniscus, posterior cruciate ligament, anterior cruciate ligament, patellar tendon, and muscle.ResultsThe phantom study demonstrated PM-UTE-AdiabT1ρ 's high sensitivity to compositional changes, its high reproducibility, and its strong linear correlation with continuous wave-T1ρ measurement. The ex vivo and in vivo knee studies demonstrated average T1ρ values of 105.6 ± 8.4 and 77.9 ± 3.9 ms for the femoral cartilage, 39.2 ± 5.1 and 30.1 ± 2.2 ms for the meniscus, 51.6 ± 5.3 and 29.2 ± 2.4 ms for the posterior cruciate ligament, 79.0 ± 9.3 and 52.0 ± 3.1 ms for the anterior cruciate ligament, 19.8 ± 4.5 and 17.0 ± 1.8 ms for the patellar tendon, and 91.1 ± 8.8 and 57.6 ± 2.8 ms for the muscle, respectively.ConclusionThe 3D PM-UTE-AdiabT1ρ sequence allows volumetric T1ρ assessment for both short and long T2 tissues in the knee joint on a clinical 3 T scanner.

Background: In basketball, changing direction is one of the primary mechanisms of anterior cruciate ligament (ACL) injury, often occurring within complex game situations with high cognitive demands. It is unknown how visual attention affects sidestep cutting kinematics during the entire energy absorption phase of the cut in an ecologically valid environment. Purpose: The purpose of this research was to study the effect of added cognitive load, in the form of increased visual attentional demands, on sidestep cutting kinematics during the energy absorption phase of the cut in an ecologically valid environment. Study Design: Crossover Study Methods: Fifteen male basketball players (aged 22.1 ± 2.3) performed ten sidestep cutting movements without (BASE) and with (VIS) a visual attention dual task. 3D kinematics of the hip, knee and ankle were recorded utilizing Xsens IMU motion capture. Temporal kinematics were analyzed using Statistical Parametric Mapping. Discrete time point kinematics were additionally analyzed at initial contact (IC) and at peak knee flexion utilizing paired t-tests. Effect sizes were calculated. Results: Hip flexion was significantly reduced in the VIS condition compared to the BASE condition (p<0.01), including at IC (VIS 35.0° ± 7.2°, BASE 40.7° ± 4.9°, p=0.02, d=0.92) and peak (VIS 37.8° ± 9.7°, BASE 45.5° ± 6.9°, p=0.001, d=0.90). Knee flexion was significantly reduced in the VIS condition, in comparison to the BASE condition (p<0.01), at peak (VIS 59.9° ± 7.5°, BASE 64.1° ± 7.4°, p=0.001, d=0.55). Conclusion: The addition of visual attention during sidestep cutting altered lower limb kinematics, which may increase ACL injury risk. It is suggested that ACL injury risk screening and prevention should include sidestep cutting with visual attentional demands, in order to mimic the cognitive demands of the sports environment. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Background: Changes in cortical activation patterns after rupture of the anterior cruciate ligament (ACL) have been described. However, evidence of these consequences in the early stages following the incident and through longitudinal monitoring is scarce. Further insights could prove valuable in informing evidence-based rehabilitation practices. Purpose: To analyze the angular accuracy, neuromuscular, and cortical activity during a knee joint position sense (JPS) test over the initial six months following ACL reconstruction. Study design: Cohort Study Methods: Twenty participants with ACL reconstruction performed a JPS test with both limbs. The measurement time points were approximately 1.5, 3-4 and 6 months after surgery, while 20 healthy controls were examined on a single occasion. The active JPS test was performed seated with a target angle of 50° for two blocks of continuous angular reproduction (three minutes per block). The reproduced angles were recorded simultaneously by an electrogoniometer. Neuromuscular activity of the quadriceps muscles during extension to the target angle was measured with surface electromyography. Spectral power for theta, alpha-2, beta-1 and beta-2 frequency bands were determined from electroencephalographic recordings. Linear mixed models were performed with group (ACL or controls), the measurement time point, and respective limb as fixed effect and each grouping per subject combination as random effect with random intercept. Results: Significantly higher beta-2 power over the frontal region of interest was observed at the first measurement time point in the non-involved limb of the ACL group in comparison to the control group (p = 0.03). Despite individual variation, no other statistically significant differences were identified for JPS error, neuromuscular, or other cortical activity. Conclusion: Variation in cortical activity between the ACL and control group were present, which is consistent with published results in later stages of rehabilitation. Both indicate the importance of a neuromuscular and neurocognitive focus in the rehabilitation. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Background: Athletes at risk for anterior cruciate ligament (ACL) injury have concurrent deficits in visuocognitive function and sensorimotor brain functional connectivity. Purpose: This study aimed to determine whether visual perturbation neuromuscular training (VPNT, using stroboscopic glasses and external visual focus feedback) increases physical and cognitive training demand, improves landing mechanics, and reduces neural activity for knee motor control. Design: Controlled laboratory study. Methods: Eight right leg dominant healthy female athletes (20.4±1.1yrs; 1.6±0.1m; 64.4±7.0kg) participated in four VPNT sessions. Before and after VPNT, real-time landing mechanics were assessed with the Landing Error Scoring System (LESS) and neural activity was assessed with functional magnetic resonance imaging during a unilateral right knee flexion/extension task. Physical and cognitive demand after each VPNT session was assessed with Borg's Rating of Perceived Exertion (RPE) for both physical and cognitive perceived exertion and the NASA Task Load Index. Descriptives and effect sizes were calculated. Results: Following VPNT, LESS scores decreased by 1.5 ± 1.69 errors with a large effect size (0.78), indicating improved mechanics, and reductions in BOLD signal were observed in two clusters: 1) left supramarginal gyrus, inferior parietal lobule, secondary somatosensory cortex (p=.012, z=4.5); 2) right superior frontal gyrus, supplementary motor cortex (p<.01, z=5.3). There was a moderate magnitude increase of cognitive RPE between the first and last VPNT sessions. Conclusion: VPNT provides a clinically feasible means to perturbate visual processing during training that improves athletes' real-time landing mechanics and promotes neural efficiency for lower extremity movement, providing the exploratory groundwork for future randomized controlled trials. Level of evidence: Level 3 [ABSTRACT FROM AUTHOR]

Deep learning is a powerful branch of machine learning, which presents a promising new approach for diagnose diseases. However, the deep learning for detecting anterior cruciate ligament still limits to the evaluation of whether there are injuries. The accuracy of the deep learning model is not high, and the parameters are complex. In this study, we have developed a deep learning model based on ResNet-18 to detect ACL conditions. The results suggest that there is no significant difference between our proposed model and two orthopaedic surgeons and radiologists in diagnosing ACL conditions. [ABSTRACT FROM AUTHOR]

Background: The optimal treatment for anterior cruciate ligament (ACL) injuries with early-stage symptomless osteoarthritis (OA) remains unclear. This study aimed to compare the clinical outcomes of ACL reconstruction (ACLR) in patients with ACL injury in the presence and absence of early-stage symptomless OA. Methods: Medical records of patients with early-stage symptomless OA who sustained ACL injury and underwent ACLR from January 2018 to December 2020 at a single institution were retrospectively reviewed. Radiography and magnetic resonance imaging were performed preoperatively to identify ACL injury and OA. Patients with ACL injury and early-stage symptomless OA (combined group, n = 14) were matched at a 1:2 ratio with patients with ACL injury (isolated group, n = 32). Data on demographic characteristics, pain and functional outcomes (visual analogue scale, Tegner, Lysholm, and International Knee Documentation Committee scores and range of motion), and imaging outcomes were collected. Complications were recorded, and outcomes were compared between the groups. Results: Forty-six patients (26 males, 20 females) were included in this study, among whom 14 had ACL injury and early-stage symptomless OA, whereas 32 sustained isolated ACL injury (average follow-up duration: 3.4 ± 1.0 years). At the final follow-up, pain and functional outcomes similar to those in patients with isolated ACL-deficient knees were achieved in the combined group; acute-stage ACLR resulted in significantly better outcomes (p < 0.05). No significant radiographic progression of OA or complications were observed. Conclusions: Knee function in patients with ACL injuries and early-stage symptomless OA who underwent ACLR was the same as that in patients with isolated ACL-deficient knees. Furthermore, ACLR had a beneficial effect on knee outcomes. The subgroup analysis revealed that acute-stage ACLR could lead to better outcomes in patients with ACL injuries and early-stage symptomless OA. [ABSTRACT FROM AUTHOR]

Conventional low-pass filtering of 3D motion capture signals prior to estimating knee joint moments and ACL injury risk has known limitations. This study aimed to evaluate the fractional Fourier filter (FrFF), which employs a time-varying cut-off frequency, for assessing peak knee moments during common ACL injury risk screening tasks. Ground reaction force and motion data were collected from 23 team sport athletes performing 45° unanticipated sidesteps and drop jumps. Peak knee abduction, internal rotation and non-sagittal moments were estimated using inverse dynamics after five different low-pass filter approaches were applied (FrFF vs. four variations of a fourth-order Butterworth filter). The FrFF produced peak knee moments larger than "matched" (i.e. force and motion cut-off frequencies were equivalent) and closer to "unmatched" (i.e. force and motion cut-offs were different) Butterworth filter approaches and removed problems with representing foot-to-ground impact peaks. Participants with larger peak moments were identified as "at risk" of injury irrespective of filter approach, but the FrFF identified "at risk" classifications conventional approaches did not. Preliminary evidence suggests that the FrFF displays enhanced sensitivity to movement strategies that induce high knee loads. This was most evident for sidestepping, with more research warranted to optimise the FrFF for drop jumps. [ABSTRACT FROM AUTHOR]

Purpose: To determine the optimal angles for independent femoral tunnel drillings in single-bundle anterior cruciate ligament reconstruction (ACLR) in different races and genders with the aim of preventing damage to lateral femoral anatomic structures (LFAS), posterior cortex and medial femoral condyle. Methods: This study included 180 volunteers, including 90 Caucasian and 90 matched Chinese. Magnetic resonance imaging (MRI) was used to scan the knees to create three-dimensional bone models, the ACL femoral footprint centre and the LFAS. In each femur model, femoral tunnels were established using a set of 16 distinct angular combinations: 15°, 30°, 45°, and 60° in the axial plane, as well as 15°, 30°, 45°, and 60° in the coronal plane. The minimum distance from the tunnel exit to the LFAS was evaluated, and the tunnel length, posterior cortex damage and medial femoral condyle injury were assessed. Results: Among the 180 patients with simulated ACL femoral tunnels, there was damage to the anatomical structure in parts of the model. According to the Cochran Q test results (P < 0.001), the percentage of safe tunnels varied significantly among the 16 different drilling angle combinations. The overall occurrence of the tunnel exit causing injury to LFAS were 8.3% and 8.1% in Chinese and Caucasian groups (P = 0.786). The means for tunnel length in Caucasians was 40.1 ± 7.9 mm, respectively; for Chinese, the results was 38.8 ± 6.6 mm (P < 0.001). Females had significantly shorter femoral tunnels than males in both Chinese and Caucasian (P < 0.001). The overall invasion rate of the posterior cortex and medial femoral condyle were 32.6% and 7.4% for Chinese; 31.0% and 7.4% for Caucasians, respectively. Conclusion: To reduce risks of injury to anatomical structures, such as the LFAS, posterior cortex and medial femoral condyle, specific angle combinations of 30°/45°, 45°/30°, 45°/45°, 45°/60°, 60°/30°, 60°/45° and 60°/60° should be used when creating the femoral tunnel in single-bundle ACLR. The selected drilling angles are critical for optimizing femoral tunnel placement. [ABSTRACT FROM AUTHOR]

Background: Essential amino acid (EAA) and omega-3 fatty acid ingestion independently attenuate leg skeletal muscle disuse atrophy in uninjured persons. However, no data exist regarding the effectiveness of combined EAA and omega-3 fatty acid ingestion to mitigate skeletal muscle disuse atrophy in response to anterior cruciate ligament reconstruction (ACLR) surgery. This pilot trial will explore the feasibility of recruitment and retention of ACLR outpatients from a single center across 18 months to consume either a combination of omega-3 fatty acids and EAAs, or a placebo control, for 4 weeks before and 2 weeks after surgery. Methods: Thirty adult (≥ 18 years old) ACLR outpatients will be recruited for this single center, double-blind, two-arm randomized controlled feasibility pilot trial. Participants will consume either 5 g⋅day−1 of omega-3 fatty acids (fish oil) and 40 g⋅day−1 of EAAs or 5 g⋅day−1 of a control fatty acid mixture (safflower oil) and 40 g⋅day−1 of non-essential amino acids (NEAAs). Fatty acid supplements will be consumed 4 weeks before and for 2 weeks after ACLR surgery, whereas the EAAs and NEAAs will be consumed 1 week before and for 2 weeks after ACLR surgery. The primary outcomes are feasibility of recruitment and retention, with the goal to recruit 30 outpatients across 18 months and retain 22 participants upon completion of the study protocol following 12 weeks of data collection. These results will be reported using descriptive statistics, along with reasons and timepoints for study dropout. Secondary exploratory outcomes will be reported using inferential statistics for purposes of hypothesis generation and elucidation of mechanistic targets for future work; no inferences to clinical efficacy will be made. These outcomes include integrated rates of skeletal muscle protein synthesis, skeletal muscle protein content and expression of translation factors, skeletal muscle and erythrocyte phospholipid composition, and measures of skeletal muscle mass, strength, and power. Impact: This work will set the foundation for a future randomized controlled trial powered to detect an effect of EAA + omega-3 fatty acid intake on skeletal muscle size or function in response to ACLR surgery. Trial registration: ClinicalTrials.gov, NCT06233825. Registered 31 January 2024. https://clinicaltrials.gov/study/NCT06233825?term=NCT06233825&rank=1 [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Level of Evidence Despite the clinical utility of the pivot shift exam, the requisite applied forces and torques to elicit a pivot shift remain unclear. The purposes of this study are (1) to identify the greatest forces and torques applied to the knee during the pivot shift exam and (2) to evaluate if the applied loads differ among experienced surgeons.Three cadaveric hemipelvis‐to‐toe specimens (ages 53, 36 and 31 years; two males and one female) with no history of knee or hip injury were utilized. The experimental setup consisted of securing the hemipelvis to a mounting frame via an external fixator to simulate patient positioning during the clinical exam. The hemipelvis, femur, and tibia were spatially tracked by motion capture and the applied loads were measured using a 6‐axis force‐torque sensor. After sectioning the anterior cruciate ligament (ACL), three board‐certified sports medicine surgeons then performed the pivot shift exam on each specimen utilizing their preferred technique. Forces (compression‐distraction, anterior‐posterior, and medial‐lateral) and torques (varus‐valgus, internal‐external rotation, and flexion‐extension) applied to the knee joint immediately preceding the reduction of the proximal lateral tibia during each pivot shift exam were calculated.Compression was the largest applied force averaging 95 N ± 15 N for all surgeons and knees, which was at least 4.5 times greater, on average, than the applied anterior and applied medial tibial forces (p < 0.0001). Valgus was the largest of the three applied torques, averaging 8.5 ± 2.1 Nm. Internal rotation torque was 3.7 times less, on average, than the applied valgus torque (p < 0.0001). Each surgeon applied compressive force. However, anterior force was more variable among surgeons, with one of the three surgeons applying minimal anterior force (p ≤ 0.024). The magnitude of applied torques was similar among examiners (n.s).Compressive force and valgus torque were the predominant applied loads during the pivot shift exam. A lower magnitude of internal rotation torque was also applied. The anterior force was not consistently applied among examiners. These data can better inform clinical, cadaveric, and computational studies utilizing the pivot shift exam to assess knee biomechanics and can be used to educate trainees in conducting this complex manoeuvre.An in vitro biomechanic study. [ABSTRACT FROM AUTHOR]

The procedure of anterior cruciate ligament (ACL) allograft preparation can be divided into fresh-frozen method (FF-allograft) or freeze-dried method (FD-allograft). This study aims to biomechanically and histologically compare the graft to bone tunnel integration between the two allografts. In-vitro results indicated that FF-allograft and FD-allograft showed excellent biocompatibility and biomechanics, while FD-allograft showed a denser collagen fiber arrangement than FF-allograft and autograft. Then, in-vivo preformation of the FF-allograft, FD-allograft, and autograft on bone tunnel integration was evaluated via a canine ACL reconstruction model. In-vivo results indicated that no signs of infection or osteoarthritis were shown in the femur-graft-tibia complexes, but more vascularity and synovitis formed around the implanted FF-allograft. Micro-computed tomography showed that peri-graft bone in the FF-allograft group was significantly increased and remodeled compared with the FD-allograft group; Histologically, the FF-allograft group exhibited similar graft-bone tunnel healing to the FD-allograft group. Tartrate-resistant acid phosphatase (TRAP) staining showed significantly more osteoclasts presented in the FD-allograft group compared to the FF-allograft group. Meanwhile, a significantly higher failure load was shown in the FF-allograft group when compared with the FD-allograft group (P < 0.05). In conclusion, the FF-allograft integrated more firmly into the bone tunnel than the FD-allograft when used in ACL reconstruction. [ABSTRACT FROM AUTHOR]

Background: Considering the low rate of qualitative studies on athletes with anterior cruciate ligament reconstruction (ACLR), aiming to access in-depth data, we thought that the utilization of the qualitative method would allow us to collect the appropriate and sufficient data to yield novel findings and achieve sound conclusions. The study's aim was to investigate anterior cruciate ligament (ACL) injury experience processes in athletes who had undergone isolated ACLR, reveal the clinically related milestones, and highlight the necessary gaps. Methods: Semi-structured interview techniques, in-depth follow-up questions, and thematic analysis were used to explore the experiences of participants with isolated ACL injuries 1–3 years after surgical treatment. The study was conducted in the Orthopaedics and Traumatology outpatient clinic of the Adana City Training and Research Hospital and included 14 male athletes who had undergone isolated primary ACLR. The study group's demographic and qualitative data were collected in the first week of September 2023. The member checking process was completed in the third following week. A thematic analysis checklist was used to ensure the reliability of the thematic analysis. The Consolidated Criteria for Reporting of Qualitative Research (COREQ) guidelines were followed. Results: The experiences of 14 patients (22.78 ± 3.76 years, all males) were summarized into four themes that emerged from the data analysis process: 'The Distinctions in the Participants' Experiences Regarding the Moment of Injury,' 'Gathering Information about the ACL Injury,' 'Factors That Facilitate The Treatment Process and Reinforce Positive Experiences,' and 'Desperate Plight: Main Points of Patients' Negative Experiences.' Based on the main themes, there were 14 subthemes. Conclusions: Our study revealed that varying perceptions of ACL injury presented by the participants, which were caused by all stakeholders, including themselves, the professional environment, family members, social network, and the healthcare staff, showed that the physical and psychological impacts of the injury were observed in different severity levels at each stage of the process. We believe that an extensive guide for athletes with ACL injuries that includes all components of well-being and displays the required details for the sports club/coach, family/companion, and physician. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to identify the differences in anatomical factors between the patients who underwent revision and primary anterior cruciate ligament reconstructions (ACLR) and compare the outcomes between the 2 surgeries. Design: Retrospective cohort study. Setting: Single institution tertiary academic center between 2014 and 2020. Patients: A total of 84 matched patients who underwent revision (group I) or primary ACLR (group II). Interventions: Radiological evaluations were performed using side-to-side differences (SS-D), femorotibial angle, and posterior tibial slope. The medial meniscus posterior horn status as width (MMPHW), medial tibial plateau width (MTPW), notch configurations, tunnel positions, and sagittal graft angle were measured using 3D-CT and magnetic resonance imaging (MRI). MainOutcomeMeasures: Graft signals were assessed using MRI. The clinical outcomes were assessed. Results: Group I showed larger SS-D and higher mean Howell grade of anterior cruciate ligament (ACL) graft than group II (P50.002 and P50.004, respectively). Multivariate regression analyses showed that the decreased MMPHW/MTPW ratio (P 5 0.010) and notch width index (P, 0.007) were significantly independent factors associated with the higher Howell grade of ACL grafts. The decreased MMPHW/MTPW ratio (P<0.001) was a significantly independent factor associated with larger SS-D. In the subgroup analysis, all patients in the notchplasty group showed wider notches postoperatively (P, 0.001). Conclusions: Revision ACLRs resulted in worse ACL signal intensity and stability outcome. The results of this study suggest that it may be important to preserve the MMPHW as much as possible and check notch configurations, especially during a revision ACLR. [ABSTRACT FROM AUTHOR]

Introduction: Osteoarthritis (OA) is a prevalent clinical chronic degenerative condition characterized by the degeneration of articular cartilage. Currently, drug treatments for OA come with varying degrees of side effects, making the development of new therapeutic approaches for OA imperative. Mesenchymal stem cells (MSCs) are known to mitigate the progression of OA primarily through paracrine effects. The conditioned medium (CM) derived from MSCs encapsulates a variety of paracrine factors secreted by these cells. Methods: In this study, we investigated the effect of the CM of infrapatellar fat pad-derived MSCs (IPFSCs) on OA in vitro and in vivo, as well as and the potential underlying mechanisms. We established three experimental groups: the normal group, the OA group, and the CM intervention group. In vitro experiments, we used methods such as qPCR, Western blot, immunofluorescence, and flow cytometry to detect the impact of CM on OA chondrocytes. In vivo experiments, we evaluated the changes in the knee joints of OA rats after intra-articular injection of CM treatment. Results: The results showed that injection of CM into the knee joint inhibited OA development in a rat model induced by destabilization of the medial meniscus and anterior cruciate ligament transection. The CM increased the deposition of extracellular matrix-related components (type II collagen and Proteoglycan). The activation of PI3K/AKT/NF-κB signaling pathway was induced by IL-1β in chondrocytes, which was finally inhibited by CM-IPFSCs treatment. Conclusion: In summary, IPFSCs-CM may have therapeutic potential for OA. [ABSTRACT FROM AUTHOR]

Introduction: therapeutic equivalence has been established in the effectiveness of peripheral nerve blocks in the management of pain in the postoperative period of anterior cruciate ligament reconstruction. However, it is unknown whether this effect is modulated by the anesthesiologist’s experience. The objective was to describe the effectiveness of peripheral nerve blocks during the first 24 hours of the postoperative period, considering patient characteristics and the anesthesiologist’s experience. Material and methods: a retrospective cohort study was conducted from 2015 to 2017. Patients who received a femoral canal block, femoral nerve block, or spinal anesthesia were included. All data were obtained from the patient’s medical records, with pain assessed using a visual analog scale recorded in the medical records. A robust, non-parametric kernel regression model was generated to estimate the effect of the variables. Results: out of 480 clinical records, 168 were included in the analysis. The period of greatest pain was between eight and 12 hours, with a non-success rate of up to 22.9%. No differences were found between peripheral nerve blocks. The anesthesiologist’s experience did not influence the analgesic effect, while the use of a bone-tendon-bone graft determined greater postoperative pain. Conclusion: in minimally invasive procedures, good pain management outcomes could be observed independently of the anesthesiologist’s experience. [ABSTRACT FROM AUTHOR]

Introduction: ACL tears are the most common injuries in kabaddi, an inherently violent high pivoting and high-velocity direct contact sport. Combined ACL and MCL injuries and combined ACL and ALL injuries have been better understood but there is a lacuna of literature on these combined injuries in kabaddi players and no literature on combined AMRI and ALRI injuries. The present prospective cohort study aims to assess knee outcomes and return to sport for these injuries in elite kabaddi players. Methods: A prospective cohort of 26 elite kabaddi players with clinical and MRI findings of ACL and MCL high-grade partial or complete tears were recruited. After ACL reconstruction and MCL repair, the resultant pivot shift was assessed against the now intact medial pillar and those with high-grade or explosive pivot were addressed using a modified deep Lemaire lateral extra-articular tenodesis. Pain scores (VAS) and knee outcomes (IKDC and Lysholm scores) were assessed pre-operatively and at regular intervals until 1-year follow-up. Return to sport and complications were also assessed. Results: There was significant improvement in pain and knee scores throughout the study period, with most patients achieving full scores by six months duration. Return to sport was 96% and return to sport at pre-injury level was 77%. Complication rate of the combined triple procedure was low (< 5%), with most complications being minor. Conclusion: The triple procedure of ACL reconstruction, MCL repair and Lateral extraarticular tenodesis successfully addressed the combined AMRI and ALRI in elite kabaddi players with a high rate of return to sport, excellent knee outcomes and low complication rate. [ABSTRACT FROM AUTHOR]

Background: The quadrant method is widely used to determine the femoral footprint center (FFC) on radiographs or computed tomography (CT) and can also describe the tibial footprint center (TFC). However, its application on three-dimensional (3D) magnetic resonance imaging (MRI) has been limited. This study aims to describe the ACL footprint center position on 3D MRI of healthy knees using the quadrant method. Methods: Proton density (PD) sequence 3D MRI was conducted on 45 intact knees, aged 18 to 45 years. The centers of the ACL footprints were determined, and 2D simulated radiographic images were generated from the 3D MRI data. The quadrant method was then applied to calculate the positions of the footprint centers. Results: The FFC was located at 31.6% in the deep–shallow (DS) direction and 31.3% in the high–low (HL) direction. The TFC was positioned at 45.1% in the mediolateral (ML) direction and 39.9% in the anteroposterior (AP) direction. Conclusions: The ACL footprint centers identified in this study were positioned similarly to previous studies, with the exception of the TFC in the ML direction, which was found to be more medial. This approach has the potential to enhance preoperative planning and intra-operative navigation in ACL reconstruction surgeries. [ABSTRACT FROM AUTHOR]

Background/Objectives: The optimal graft, particularly in combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries, remains controversial. We evaluated the influence of graft choice between bone-patellar tendon-bone (BPTB) and hamstring autografts on clinical outcomes in combined ACL and MCL injuries. Methods: This retrospective analysis included patients with concurrent ACL and MCL injuries who underwent single-bundle ACL reconstruction with BPTB (group B) or hamstring (group H) grafts, between 2010 and 2019, with a ≥2-year follow-up. Patients were classified based on the MCL injury grade (I, II, or III). Clinical outcomes were assessed through knee stability evaluations using valgus stress radiographs and the KT-2000 arthrometer, patient-reported outcomes using the International Knee Documentation Committee (IKDC) subjective score and Lysholm score, and radiologic outcomes using the IKDC radiographic grade. Results: The study included 169 patients (group B, 92; group H, 77). No significant between-group differences in knee stability or functional outcomes were found after follow-up. Within the same MCL injury grade, particularly in high-grade MCL injuries, BPTB grafts resulted in significantly better medial stability (side-to-side difference in medial joint opening on valgus stress radiographs: grade II, p = 0.006; grade III, p = 0.039) and functional outcomes (IKDC subjective score: grade II, p = 0.045; grade III, p = 0.038) than hamstring grafts. In the hamstring group, higher-grade MCL injuries were associated with worse outcomes (Lysholm knee score, p = 0.009; IKDC subjective score, p = 0.015). Conclusions: Graft choice in ACL reconstruction with concomitant MCL injuries may affect clinical outcomes, particularly in high-grade MCL injuries. Although both graft types performed similarly overall, BPTB grafts provided superior medial stability and functional results in higher-grade MCL injuries. However, caution is needed when interpreting these results due to limitations such as the small sample size and the lack of randomization in graft selection. [ABSTRACT FROM AUTHOR]

Purpose: To compare the difference of angle of the lower portion of the posterior cruciate ligament (PCL) measured via magnetic resonance imaging (MRI) in patients with and without partial anterior cruciate ligament (ACL) tears and to investigate the effectiveness of the angle of the lower portion of the PCL in diagnosing partial ACL tears. Methods: From January 2022 to December 2022, a cohort of consecutive patients presenting with ACL tears who underwent ACL reconstruction and patients with isolated meniscus tears undergoing arthroscopic surgery were enroled for this study. The angle of the inferior portion of the PCL comprises α and β angles, and the posterior offset of the lateral condyle were measured on the MRI and compared between the partial ACL tear and control groups. Receiver operating characteristic curves, the areas under the curve (AUCs) and the 95% confidence intervals (CIs) were calculated to identify cutoff values for diagnosing partial ACL injuries. Results: Following an assessment of cohort eligibility and matching for age and sex, 100 patients were included in this study. The mean age of the cohort was 46.1 ± 10.3 years. The AUC for the α angle was 0.88 (95% CI, 0.82–0.94), with a sensitivity of 0.74 and specificity of 0.84 for predicting partial ACL ruptures; the α angle cutoff value was 73.6° (diagnostic odds ratio (OR), 14.10; 95% CI, 5.33–37.28). The AUC for the β angle was 0.86 (95% CI, 0.79–0.93), with a sensitivity of 0.64 and a specificity of 0.92 for predicting partial ACL ruptures; the β angle cutoff value was 73.3° (diagnostic OR, 14.54; 95% CI, 5.76–36.68). Conclusions: A small α angle and a large β angle were associated with partial ACL tears. The angle of the distal portion of the PCL was simple to measure and reproducible, enhancing the diagnosis of partial ACL tears. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: Badminton requires fast and pivoting movements, putting athletes at risk of sustaining an anterior cruciate ligament (ACL) injury. The primary purpose is to investigate the return to sport (RTS) and the return to performance (RTP) after an ACL injury in elite badminton athletes. The secondary purpose is to describe ACL injury mechanisms in elite badminton players. Methods: Athletes within the top 200 of the Badminton World Federation World Ranking who sustained an ACL injury between January 2001 and December 2021 were retrospectively included. An anonymous online survey was created in eight languages. RTS, RTP and contributing factors were analysed among athletes aiming to RTP. The injury mechanism was analysed in all participants. Results: Sixty‐six athletes from 32 countries were included. Fifty‐seven athletes (86.4%) aimed to RTP. Forty‐eight out of 57 (84.2%) did RTS. Twenty‐nine (50.9%) managed to successfully RTP. Forty‐nine (74.2%) of ACL injuries occurred during a competition, 14 (21.2%) occured during training. Thirty‐one (49.2%) occurred in the rear court backhand side and 47 (74.6%) occurred during landing after a jump. Conclusion: Forty‐eight out of 57 (84.2%) athletes managed to RTS. Half of the athletes managed to successfully RTP. Most of the ACL injuries occurred during competition, in the rear court backhand side and during landing after a jump. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to compare 45° and 60° of sagittal femoral tunnel angles in terms of anterior tibial translation (ATT), valgus angle and graft in situ force following anterior cruciate ligament reconstruction (ACLR). Methods: Ten porcine knees were subjected to the following loading conditions: (1) 89 N anterior tibial load at 35° (full extension), 60° and 90° of knee flexion and (2) 5 N m valgus tibial moment at 35° and 45° of knee flexion. ATT and graft in situ force of the intact anterior cruciate ligament (ACL) and ACLR were collected using a robotic universal force/moment sensor (UFS) testing system for (1) ACL intact, (2) ACL‐deficient (ACLD) and (3) two different ACLR using different sagittal femoral tunnel angles (coronal 45°/sagittal 45° and coronal 45°/sagittal 60°). Results: During the anterior tibial load, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly higher ATT than that of the ACL‐intact knees at 60° of knee flexion (p < 0.05). The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 60° had significantly lower graft in situ force than that of the ACL‐intact knees at 60° and 90° of knee flexion (p < 0.05). During the valgus tibial moment, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly lower graft in situ force than that of the ACL‐intact knees at all knee flexions (p < 0.05). Conclusions: The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° provided similar ATT, valgus angle and graft in situ force to that of ACLR knees at coronal 45°/sagittal 60°. Therefore, both femoral tunnel angles could be used in ACLR, as the sagittal femoral tunnel angle does not appear to be relevant in post‐operative knee stability. Level of Evidence: Not applicable. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study was to determine whether the grade of osteoarthritis (OA) is higher with single‐bundle (SB) or double‐bundle (DB) anterior cruciate ligament (ACL) reconstruction. The hypothesis was that there will be no difference in the grade of OA between the techniques. Methods: This study was a randomised controlled trial (RCT) with a follow‐up period of 15 years. Patients were randomly assigned to either the SB group (n = 78) or the DB group (n = 75). Surgical techniques were anatomic, and the rehabilitation protocol was standardised. Evaluation included Kellgren–Lawrence (KL) difference and absolute OA results. OA was defined as a KL grade of at least 2. Results: At 15‐year follow‐up, information was available on 101 patients (66%), of whom 56 (37%) were accepted in the final statistical analysis. No difference was found between the SB and DB techniques in terms of KL difference or absolute OA results. Significantly less OA was found in the contralateral knee (21%) than in the reconstructed knee (59%) (p < 0.001). Patients with meniscal tears who underwent partial meniscal resection during ACL reconstruction had a significantly higher rate of OA changes (82%) compared with patients with isolated ACL tears (33%) (p < 0.001). A longer delay between initial injury and surgery did not appear to affect the severity of the KL classification. Conclusion: At 15‐year follow‐up, no difference was found between the DB and SB techniques in terms of OA. Level of Evidence: Level I. [ABSTRACT FROM AUTHOR]

Purpose: To validate the New Zealand Anterior Cruciate Ligament (ACL) Registry's capture rate of revisions by cross‐referencing Registry data with reoperations data recorded by the Accident Compensation Corporation (ACC) and identify risk factors for all‐cause reoperation. Methods: Primary ACL reconstructions performed between April 2014 and September 2019 were individually matched on a record‐by‐record basis between the two databases. The ACC database was used to identify patients who underwent a reoperation with manual review of operation notes to identify whether a revision or other procedure was performed. This was combined with the number of revisions separately recorded in the New Zealand ACL Registry, which was used as the denominator value to calculate the Registry's capture rate of revisions. Patient and surgical data recorded in the Registry were analysed to identify independent predictors for all‐cause reoperation. Results: A total of 8046 primary ACL reconstructions were matched between the New Zealand ACL Registry and the ACC databases. The reoperation rate was 8.9% (n = 715) at a mean follow‐up of 2.5 years. Meniscal‐related procedures were the most common reoperation (n = 299, 3.7%), followed by revision ACL reconstruction (n = 219, 2.7%), arthrofibrosis (n = 185, 2.3%), cartilage (n = 56, 0.7%) and implants (n = 32, 0.4%). The New Zealand ACL Registry captured 96% of revisions. Younger age (hazard ratio [HR] > 1.4, p < 0.001), earlier surgery (HR > 1.3, p = 0.05), concurrent meniscal repair (medial meniscus HR = 1.9, p < 0.001 and lateral meniscus HR = 1.3, p = 0.022) and hamstring tendon autografts (HR = 1.4, p = 0.001) were associated with a higher risk of reoperation. Conclusion: The New Zealand ACL Registry captured 96% of revisions. Risk factors for all‐cause reoperation included younger age, earlier surgery, meniscal repair and hamstring tendon autografts. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine how preoperative health‐related quality of life (HRQoL) is affected by the duration of the wait time (WT) for anterior cruciate ligament reconstruction (ACLR) once a decision is made to proceed with surgery. Methods: This was a multi‐centre prospective cohort study. One hundred and twenty‐two patients 14 years of age and above waiting for ACLR completed the International Knee Documentation Committee (IKDC) demographic, current health assessment and subjective knee evaluation (SKF) forms on the day of decision to operate and the day of surgery. Changes in scores were analyzed for the entire cohort, adjusted for WTs and a subset was compared for patients with isolated anterior cruciate ligament (ACL) tears and ACL tears with concurrent meniscal involvement. Changes in HRQoL scores from the day of the decision to operate to the 9‐month postoperative appointments were also assessed. Results: Energy/Fatigue (p < 0.05), Pain (p < 0.05), General Health (p < 0.05) and the IKDC‐SKF Score (p < 0.05) significantly increased between the day of the decision to operate and the day of surgery. Only the change in IKDC‐SKF score remained significantly higher after adjusting for WT. Baseline HRQoL scores significantly improved by the 9‐month postoperative appointment. Conclusion: The length of time waiting for ACLR did not adversely influence HRQoL in this study. However, low preoperative HRQoL and the significant improvement in HRQoL of patients followed postoperatively suggest that timely surgery is beneficial for this patient population. Level of Evidence: Level II. [ABSTRACT FROM AUTHOR]

This document discusses a case of a painless knee mass in a young adult. The MRI showed a soft tissue lesion in the posterior recess of the knee, closely related to the anterior cruciate ligament. A provisional diagnosis of a complex ACL ganglion was made based on the MRI findings. However, an aspiration biopsy revealed a synovial sarcoma, a rare and aggressive soft tissue sarcoma. The document emphasizes the importance of histopathological analysis in cases of ganglion aspiration to avoid misdiagnosis. The management of synovial sarcoma involves surgical resection and, in some cases, radiotherapy or neoadjuvant chemoradiotherapy. [Extracted from the article]

Objectives: To evaluate the type and prevalence of associated injuries by using magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears. Methods: Data from the Natural Corollaries and Recovery after ACL injury multicenter longitudinal cohort study were analyzed. Between May 2016 and October 2018, patients aged between 15 and 40 years, who had experienced an ACL tear within the last 6 weeks and sought medical attention at one of seven healthcare clinics in Sweden, were invited to participate. The mean time from injury to MRI was 19.6 ± 15.2 days. An orthopedic knee surgeon and a musculoskeletal radiologist reviewed all the MRI scans. The following structures were assessed: posterior cruciate ligament (PCL), medial collateral ligament (MCL) complex, lateral collateral ligament (LCL), popliteus tendon, medial meniscus (MM), lateral meniscus (LM), and cartilage. In addition, the presence of bone bruising, impaction fractures in the lateral femoral condyle (LFC) or posterolateral tibia (PLT), and Segond fractures were also assessed. Results: A total of 254 patients (48.4% males) with a mean age of 25.4 ± 7.1 years were included. The prevalence of associated injuries was as follows: PCL (0.4%), MCL {41.3% [superficial MCL and deep MCL (dMCL) 16.5%; isolated dMCL 24.8%]}, LCL (2.4%), MM (57.4%), LM (25.2%), cartilage (15.0%), bone bruising (92.9%), impaction fracture in the LFC (45.7%) and PLT (4.7%), and Segond fracture (7.5%). Conclusions: The prevalence of associated injuries in patients with ACL tears was high. The findings reported in this study may serve as a reference tool for orthopedic surgeons and radiologists in the diagnosis of associated injuries using MRI in patients with ACL tears. [ABSTRACT FROM AUTHOR]

Introduction Anterior Cruciate Ligament (ACL) injuries continue to be a major source of morbidity in gymnastics. The gold standard is to perform an ACL Reconstruction (ACLR). However, injuries to the proximal femoral attachment of the ACL have demonstrated an ability to regenerate. An alternative surgical intervention to the ACLR in this ACL tear subgroup is an ACL repair. The purpose of this case report is to provide a rehabilitation progression for a female gymnast after an ACL repair with Internal Brace Ligament Augmentation (IBLA). Case Description The subject was a 16-year-old female who presented with a Sherman Type 1 proximal avulsion of her ACL. She underwent an ACL repair with IBLA. Physical therapy interventions followed a sequential and multi-phased approach based on time for tissue physiologic healing and individual progression. Patient reported outcomes including the International Knee Documentation Committee (IKDC), the Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) and the Optimal Screening for Prediction of Referral and Outcome Yellow Flag (OSPRO-YF) were assessed in conjunction with isokinetic strength and hop performance testing to determine return to sport readiness. Outcomes The subject completed 42 sessions over the course of 26 weeks in addition to a home exercise program. At return to sport, clinically meaningful improvement was observed in patient reported outcomes including the IKDC, ACL-RSI, and OSPRO-YF. Additionally, strength and hop performance surpassed established thresholds of clinical significance. The subject returned to sport at six months post-operatively. Conclusion The subject in this case report returned to full participation in gymnastics six months after an ACL repair with internal bracing following a sequential and multi-phased rehabilitation. The primary ACL repair with IBLA appeared beneficial to this patient and could benefit from additional study in other athletes and athletic populations. Level of Evidence Level 5 [ABSTRACT FROM AUTHOR]

Background Muscular strength deficits are common after ACL injury. While the Limb Symmetry Index (LSI), using the uninvolved limb as a reference, is widely used, negative strength adaptations may affect both limbs post-injury. It is uncertain how the strength of the uninvolved limb in those with an ACL injury compares to uninjured individuals, making it unclear whether it is appropriate as a benchmark for determining sufficient strength. Purpose To compare the strength of key lower extremity muscles of the uninvolved limb in those with history of ACL injury (ACL-I) to the dominant limb in individuals with no history of ACL injury (control). Study Design Cross-sectional study. Methods: A total of 5,727 military cadets were examined, with 82 females and 126 males in the ACL-I group and 2,146 females and 3,373 males in the control group. Maximum isometric strength was assessed for six muscle groups measured with a hand-held dynamometer. Separate two-way ANOVAs with limb and sex were performed for each muscle group. Results Significant main effects for limb were observed with the uninvolved limb in the ACL-I group displaying greater strength compared to the dominant limb in the control group for the quadriceps, hamstrings, and gluteus medius, but effect sizes were small (Cohen's d <0.25). Significant main effects for sex were observed with greater male muscular strength in all six muscle groups with small to large effect sizes (Cohen's d 0.49-1.46). No limb-by-sex interactions were observed. Conclusions There was no evidence of reduced strength in the uninvolved limb in those with a history of ACL injury compared to the dominant limb in those with no prior ACL injury. This finding suggests that, after clearance to return to activities, the uninvolved limb can be used as a standard for comparison of sufficient strength, including when using the LSI. Level of Evidence: Level 3 [ABSTRACT FROM AUTHOR]

This study aimed to develop and evaluate the reliability of a surface electromyography-based (sEMG) index to quantify knee muscle coactivation in healthy recreational athletes during the Lower Quarter Y-Balance Test (YBT-LQ). A prospective observational repeated measures design was used to assess both intra- and inter-rater reliability. Forty males completed three trials, with two raters independently conducting assessments. sEMG signals from the vastus medialis, vastus lateralis, biceps femoris, and semitendinosus muscles were collected to calculate four coactivation indices (CoAIs) for different muscle pairs. The reliability evaluation of these CoAIs was based on intraclass correlation coefficients. The results revealed that the reliability of the CoAIs varied depending on the muscle pair, direction, and limb examined. The highest intra- and inter-rater reliability was noted for the left lower limb in the posterolateral direction. The lowest reliability was found for the right lower limb in the anterior direction. Statistical analyses indicated significant differences in specific CoAIs across different YBT-LQ directions. These findings highlight the potential of sEMG-based CoAIs for assessing knee muscle activity during the YBT-LQ in healthy male recreational athletes. However, choosing CoAIs is critical for reliable clinical and research assessments of knee stability and neuromuscular control. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a degenerative joint disease primarily affecting the elderly. It is characterized by the progressive decline of joint cartilage and alterations in the underlying bone. Several probiotic strains have exhibited immunomodulatory and anti‐inflammatory properties. Here, we examined the functions of live and dead Clostridium butyricum GKB7 (GKB7‐L and GKB7‐D) in a preclinical anterior cruciate ligament transection (ACLT)‐enhanced OA procedure. Oral administration of GKB7‐L and GKB7‐D ameliorated ACLT‐induced bone pain as assessed by weight‐bearing behavioral testing but did not affect body weight. Micro‐computed tomography (CT) results showed that GKB7‐L and GKB7‐D diminished ACLT‐induced bone destruction and loss. GKB7‐L and GKB7‐D‐enriched therapies also reduced ACLT‐induced production of the pro‐inflammatory cytokines interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α, as well as the chondrolytic factor matrix metalloproteinase (MMP)‐3, leading to inhibition of aggrecan and collagen type II degradation and thereby blocking cartilage breakdown. We therefore suggest that oral supplementation with GKB7‐L or GKB7‐D can be beneficial in the prevention and treatment of OA. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis (OA) is featured as cartilage loss, joint pain and loss of labor, which the inflammatory reaction may play critical roles. Ononin is an isoflavone isolating from medicinal plants and has anti-inflammatory effects. Our study investigated the anti-inflammation response of ononin on OA. Methods: Anterior cruciate ligament transection (ACLT)–induced OA operation was used to establish research model, then treated with ononin for 8 weeks. The condition of joint injury was assessed using pathological staining. The concentration of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in serum were measured by Elisa kit. The expression of collagen II and matrix metalloproteinase 13 (MMP-13) proteins to assess cartilage metabolism level by immunohistochemistry and Western blot. We detected the expression of proteins involved in the MAPK and NF-κB signaling pathways. Finally, we used molecular docking to assess the affinity of ononin for the target proteins ERK1/2, JNK1/2, p38 and p65. Results: Our results confirmed that ononin ameliorated cartilage impairment through histopathological analysis by improving the morphological structures and cartilage tidal lines and decreasing Osteoarthritis Research Society International (OARSI) scores in OA rats. Moreover, ononin inhibited the secretion of above factors in OA rats. Furthermore, ononin has been shown to improve cartilage content levels in OA rats. In addition, ononin inhibited the reactivity of MAPK and NF-κB pathways in OA rats. And molecular docking indicated the ligand molecules could stably bind to the proteins of above receptors. Conclusion: Our results demonstrated that ononin may ameliorate cartilage damage and inflammatory response in OA rats by downgrading MAPK and NF-κB pathways, thus identifying ononin as a potential novel drug to treat OA. [ABSTRACT FROM AUTHOR]

Introduction: Osteoarthritis (OA) is a prevalent chronic degenerative disease, marked by a complex interplay of mechanical stress, inflammation, and metabolic imbalances. Recent studies have highlighted the potential of spermidine (SPD), a naturally occurring polyamine known for its anti-inflammatory and antioxidant properties, as a promising therapeutic agent for OA. This study delves into the therapeutic efficacy and mechanistic pathways of SPD in mitigating OA symptoms. Methods: Forty Sprague-Dawley rats were randomly assigned to four groups, including the CG (sham operation), model (anterior cruciate ligament transection [ACLT], and treatment (ACLT + two different doses of SPD) groups. In vivo, correlations between OA severity and different interventions were assessed by ELISA, X-rays, CT imaging, histological staining, and immunohistochemistry. In vitro, IL-1b was used to trigger chondrocyte inflammation, and SPD’s cytotoxicity was assessed in primary rat chondrocytes. Next, inflammatory markers, extracellular matrix (ECM) proteins, and pathway marker proteins were detected in chondrocytes administered IL-1b alone, SPD, or aryl hydrocarbon receptor (AhR) silencing, by qRT-PCR, Griess reaction, ELISA, Western blot, and immunofluorescence. Morphological alterations and pyroptosis in chondrocytes were examined by transmission electron microscopy (TEM) and flow cytometry. Results: Our research reveals that SPD exerts significant anti-inflammatory and antipyroptotic effects on IL-1b-treated chondrocytes and in anterior cruciate ligament transection (ACLT) rat models of OA, primarily through interaction with the Aryl hydrocarbon receptor (AhR). Specifically, SPD’s binding to AhR plays a crucial role in modulating the inflammatory response and cellular pyroptosis by inhibiting both the AhR/NF-kB and NLRP3/caspase-1/GSDMD signaling pathways. Furthermore, the knockdown of AhR was found to negate the beneficial effects of SPD, underscoring the centrality of the AhR pathway in SPD’s action mechanism. Additionally, SPD was observed to promote the preservation of cartilage integrity and suppress ECM degradation, further supporting its potential as an effective intervention for OA. Discussion: Collectively, our findings propose SPD as a novel therapeutic approach for OA treatment, targeting the AhR pathway to counteract the disease’s progression and highlighting the need for further clinical evaluation to fully establish its therapeutic utility. [ABSTRACT FROM AUTHOR]

Background: The literature does not clearly convey the relationship between eminential morphometry and non-contact anterior cruciate ligament (ACL) ruptures. This study attempts to reveal whether there is a relationship between non-contact ACL ruptures and eminential morphometry. Methods: Knee magnetic resonance images (MRIs) taken for the various indications between January 2022 and June 2023 were retrospectively scanned. The patients were categorized into 2 groups: those with an ACL rupture and those with an intact ACL. For each patient, eminential angle 1, eminential angle 2, medial eminential height, lateral eminential height, total eminential height, eminential width, and the ratio of tibial plateau width and eminential width to the tibial plateau width were measured by 2 different orthopedists. Patients whose MRIs were used for measurement were evaluated and grouped according to their age, sex, and injury side. Results: In total, 400 MRIs of 400 patients were included in the study. While 200 patients had an ACL rupture, 200 had an intact ACL. The total eminential height in the ACL rupture group was measured at 16.1 ± 2.6 mm and 15.5 ± 2.7 mm (p = 0.035) in the ACL intact group. Eminental width in the ACL rupture group was measured at 12.1 ± 1.9 mm and 13.0 ± 2.0 mm in the ACL intact group (p = 0.0001). The tibial plateau width was 75.4 ± 15.7 mm in the ACL rupture group and 73.6 ± 5.8 mm in the ACL intact group (p = 0.002). According to the logistic regression analysis, the p-value for males was 0.0001, and for eminential width, the p-value was 0.0001. Conclusions: A significant difference was found between the ACL rupture and the ACL intact groups regarding eminential height, eminential width, and tibial plateau width parameters. Being male and having a low eminential width were identified as independent risk factors for non-contact ACL. Trial registration: Not applicable. [ABSTRACT FROM AUTHOR]

Background: The development of less invasive all‐inside techniques regarding anterior cruciate ligament (ACL) reconstruction surgery has been associated with various advantages, including fewer complications and reduced postoperative pain. Silva et al. described a quadruple semitendinosus graft construct and suspensory button fixation for ACL reconstruction as an alternative technique. At the end of this technique, the tibial tunnel is filled with a bone autograft plug. This paper aims to examine the incorporation of the autograft and thus evaluate whether the "Silva technique" provides the same benefits as all‐inside techniques. Methods: A prospective study assessed 31 patients undergoing ACL reconstruction surgery using the "Silva technique." The cases involved in the study were skeletally mature patients with no previous history of ACL surgery or multiligamentous instability. All patients followed the same rehabilitation program and were examined at three standardized follow‐up visits: 4 months, 8 months, and 1 year postoperatively. Tegner–Lysholm knee score (TLKS), visual analog score (VAS) for pain, and the IKDC subjective knee score were completed at every visit. A knee MRI scan was performed at every scheduled visit to assess bone graft incorporation and remodeling. Results: TLKS scores revealed a considerable improvement compared to preoperative figures, from 57.2 points preoperatively to an average of 99.4 at the 12‐month follow‐up (p < 0.0001). VAS scores were substantially ameliorated after the operation and until the second follow‐up visit, from 5 before surgery to zero 8 months after the operation, with no noteworthy alterations afterward (p < 0.0001). IKDC subjective knee score outcomes were found to have increased at the last follow‐up, from 59.3 prior to surgery to 99.8 12 months postoperatively (p < 0.0001). Regarding the MRI features of the bone autograft, the tibial tunnel was entirely filled by bone formation at the last MRI scan, suggesting complete integration of the autograft in all patients. Conclusions: Bone autograft employed to seal the tibial tunnel was completely incorporated in all cases 1 year postoperatively. The "Silva technique" appears to feature all the avails of all‐inside techniques, whilst it seems to be simpler and easier than them after the surgeon is familiarized with its particular aspects. It is a robust option in orthopedic surgeons' arsenal. However, further large‐scale pertinent research is requisite to confirm the findings of this study. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the ultrastructural anatomy of the developing ACL tibial enthesis. We hypothesized that enthesis architecture would progressively mature and remodel, eventually resembling that of the adult by the early postnatal stage. Five fresh‐frozen human pediatric cadaveric knees aged 1–36 months underwent anatomical dissection to harvest the ACL insertion and underlying tibial chondroepiphysis. The samples were prepared for scanning electron microscopy (SEM) to examine the ultrastructural anatomy of the enthesis and underwent histological staining for circular polarized light (CPL) and light microscopy imaging. SEM analysis of the 1‐ and 8‐month‐old samples revealed a shallow interdigitation between the dense fibrous (ligamentous) tissue and unmineralized chondrogenic tissues, with a minimal transition zone. By 11‐month, a more complex transition zone was present. By age 19‐ and 36‐month‐old, a progressively more complex and defined fibrocartilage zone was observed. CPL analysis revealed distinct collagen fiber continuity, alignment, and organization changes over time. By 19 and 36 months, the samples exhibited complex fiber arrangements and a progression toward uniform fiber orientation. Similarly, histological analysis demonstrated progressive remodeling of the enthesis with increasing age. Our results suggest that the ACL enthesis of the developing knee begins to mimic that of an adult as early as 19 months of age, as a more complex transition between ligamentous and chondro‐epiphyseal tissue can be appreciated. We hypothesize that the observed changes are likely due to mechanical loading of the enthesis with the onset of weightbearing. Future investigations of ACL reconstruction and repair will benefit from improved understanding of the chondro‐epiphyseal/ACL regions. [ABSTRACT FROM AUTHOR]

Purpose Methods Results Conclusion Level of Evidence Posterior elongation of the physiological terminal sulcus (TS) due to lateral femoral condyle impaction fracture (LFC‐IF) after an anterior cruciate ligament (ACL) tear could potentially decrease the weight‐bearing area of the tibiofemoral joint, decrease the tension on lateral meniscus and cause flattening of the LFC which would influence rotational knee motion and cause anisometry of the lateral and anterolateral stabilizers. Therefore, the purpose of the study was to assess if the LFC‐IF elongates the physiological TS posteriorly.One hundred patients magnetic resonance images (MRIs) (75 males, 25 females, mean age 32.2 years, SD = 8.2) were included with a 1:1 ratio between the full‐thickness ACL tear group and the control group (patients with knee MRI performed due to other reasons, with no tear of ACL on MRI and negative clinical tests). Two independent raters evaluated the sagittal T1‐weighted preselected MRI scans. The principal measurement of interest was the distance from the intersection of the Blumensaat line with subchondral bone to the posterior border of the TS/LFC‐IF.The median distance from the Blumensaat line to the posterior border of the TS/LFC‐IF was significantly higher in the ACL tear group: 14.3 mm, interquartile range (IQR) = 11.6–16.4 mm versus control group: 12.8 mm, IQR = 9.0–15.0 mm, p = 0.038. Intrarater and inter‐rater reliabilities were >0.90.LFC‐IF after full‐thickness ACL tear significantly elongates the physiological TS in the posterior direction.Level III. [ABSTRACT FROM AUTHOR]

Chronic inflammation significantly contributes to the progression of osteoarthritis (OA), and an anti‐inflammatory small molecule derived from medicinal herbs could be a potential drug candidate for OA. Herein, we investigated the function and mechanism of Evodiamine (EAE), the active ingredient from Evodia rutaecarpa, in chondrocytes and macrophages in vitro and in vivo. The cytotoxicity of EAE was determined using an MTT assay. And the anti‐inflammatory and anti‐extracellular matrix (ECM) degradation effects of EAE were investigated using qRT‐PCR, western blot (WB), immunofluorescence (IF). Inductively Coupled Plasma Atomic Emission Spectrometry (ICP‐AES), Fluo‐4 AM, IF and AutoDock were used to elucidate the molecular mechanisms and signalling pathways of the reducing‐inflammatory properties of EAE on chondrocytes in vitro. Moreover, the effect of EAE on macrophage polarization was detected by IF and flow cytometry (FC). Ultimately, we explored the in vivo therapeutic efficacy of EAE in an anterior cruciate ligament transection (ACLT)‐induced OA model. The finding demonstrated that EAE blocked the phosphorylation of IKBα and Ca2+ influx, thereby curbing inflammation and ECM degradation. Additionally, EAE can prevent the polarization towards the M1 phenotype. Thus, our findings suggest that EAE has great potential as a therapeutic drug for the treatment of OA. [ABSTRACT FROM AUTHOR]

Background/Objectives: Anterior cruciate ligament (ACL) reconstruction (ACLR) is often followed by significant muscle atrophy and subsequent loss of strength. Blood flow restriction training (BFRT) has recently emerged as a potential mode of rehabilitation to mitigate these effects. The goal of this systematic review was to evaluate the efficacy of BFRT in functional recovery when compared to traditional rehabilitation methods. Methods: A literature review was conducted across July and August 2024 using multiple databases that reported randomised controlled trials comparing BFRT to traditional rehabilitation methods. Primary outcomes were changes to thigh muscle mass and knee extensor/flexor strength with secondary outcomes consisting of patient-reported functional measures (IKDC and Lysholm scores). The RoB-2 tool was used to assess the risk of bias. Results: Eight studies met the inclusion criteria; however, substantial heterogeneity prevented a meta-analysis being conducted for the primary outcomes. Three out of the five studies measuring muscle mass reported significant (p < 0.05) findings favouring BFRT. There was variation amongst the strength improvements, but BFRT was generally favoured over the control. Meta analysis of the secondary outcomes showed significant improvements (p < 0.05) favouring BFRT despite moderate heterogeneity. Conclusions: BFRT shows promise for maintaining muscle mass and improving patient reported outcomes following ACL reconstruction. However, the high risk of bias limits the strength of these conclusions. Further high-quality research needs to be conducted to establish optimal BFRT protocols for this cohort and to determine if BFRT has a place in ACL rehabilitation. [ABSTRACT FROM AUTHOR]

Background: This study aimed to evaluate the predictive value of anthropometric measurements for two-stranded peroneus longus tendon (PLT) graft thickness using ultrasonography Materials and methods: A prospective study was conducted on 204 healthy volunteers (102 males and 102 females) aged 18–40 years. Anthropometric measurements were recorded, including height, weight, body mass index (BMI), fibular length, calf circumference, and ankle circumference. The Tegner Activity Scale (TAS) was used to assess activity levels. PLT cross-sectional area (CSA) was measured using ultrasonography. Two-stranded PLT graft thickness was calculated using the previously reported formula by Luo et al. A thickness of less than 8 mm of PLT graft was accepted as an insufficient autograft for anterior cruciate ligament reconstruction (ACLR). Correlation and regression analyses were performed to identify predictors of two-stranded PLT graft thickness. Receiver operating characteristic (ROC) analysis was performed to establish the best threshold values. Results: Males had a significantly greater PLT CSA (0.17 ± 0.03 cm2) and predicted two-stranded PLT graft thickness (8.1 ± 0.6 mm) compared with females (0.15 ± 0.03 cm2 and 7.5 ± 0.6 mm, respectively; p < 0.001 for both). Correlation analysis revealed that two-stranded PLT graft thickness positively correlated with height, weight, BMI, fibular length, calf circumference, ankle circumference, and Tegner Activity Scale in both genders, with stronger correlations observed in females. The logistic regression model identified height and calf circumference as significant predictors of sufficient two-stranded PLT graft thickness (≥ 8 mm) in males, while calf circumference and the TAS were significant predictors in females. ROC analysis demonstrated that calf circumference and the TAS had acceptable discriminatory abilities in females, with 36.25 cm and ≥ 4 cutoff points, respectively. However, no anthropometric variables in males exhibited strong discriminatory abilities for predicting two-stranded PLT graft thickness Conclusions: Calf circumference and the TAS are significant predictors for two-stranded PLT autograft thickness in females. However, no anthropometric variables in males could be used strongly for prediction. These anthropometric measurements can assist in preoperative planning and decision-making, potentially improving ACLR outcomes by ensuring adequate graft thickness in females. Level of evidence: Level II prospective study [ABSTRACT FROM AUTHOR]

Simple Summary: The patellar tendon is described as an intermediate to soft structure with strain elastography, with an increase in stiffness in cases of cranial cruciate ligament rupture. This work aimed to compare the stiffness of healthy ligaments and ones of dogs who underwent TPLO or TTA and to compare the feasibility of a strain ratio with two different reference tissues (cutis/subcutis and infrapatellar fat pad) to semi-quantitatively assess ligament elasticity. The results show that after TPLO or TTA, the ligaments are characterized by increased stiffness, and the distal portion is significantly softer. The cutis/subcutis experience fewer B-mode abnormalities after TPLO or TTA. These data suggest that after surgery, the tendon may become non-uniformly stiffer. The cutis/subcutis appears to be a more reliable reference tissue than the infrapatellar fat pad. Strain elastography (SE) evaluates tissue stiffness, providing qualitative and semiquantitative evaluation, with a strain ratio (SR) > 1 indicating that the target lesion is stiffer than the reference tissue. The patellar tendon has been described as soft in healthy dogs and hard in dogs with cranial cruciate ligament rupture, but SR usefulness has not been assessed. Dogs were divided into healthy (G1) and at least 1 month after surgery (G2) groups. Thickness was recorded, and a B-mode score of 0–3 was determined based on the abnormality's severity. SE was qualitatively performed with a score of 1–4, and EI was recorded on the whole ligament and in proximal, intermediate and distal areas; SR was collected with the fat pad and cutis/subcutis. G1 was significantly thinner, with a lower score than G2 and a more elastic pattern. EI for G1 was significantly lower than G2 for the whole tendon and the single portions, and EI for the distal portion was significantly lower than the proximal and intermediate one in G2. SR was <1 in G1 and >1 in G2 for both the fat pad and cutis/subcutis. These data suggest that after surgery, the tendon may become non-uniformly stiffer. The cutis/subcutis appears to be a more reliable reference tissue than the infrapatellar fat pad. [ABSTRACT FROM AUTHOR]

Non-contact anterior cruciate ligament injuries (NC-ACLs) represent a significant concern in sports medicine, particularly among athletes and physically active individuals. These injuries not only result in immediate functional impairment but also predispose individuals to long-term issues such as recurrent instability and early-onset osteoarthritis. This narrative review examines the biomechanical, neuromuscular, and environmental factors that contribute to the high incidence of NC-ACLs and evaluates the effectiveness of current prevention and rehabilitation strategies. The review identifies key risk factors, including improper landing mechanics, deficits in neuromuscular control, and muscle imbalances, which are pivotal in the etiology of NC-ACLs. Prevention programs that incorporate plyometric exercises, strength training, and neuromuscular education have shown efficacy in reducing injury rates. Rehabilitation protocols that emphasize a gradual return to sport, focusing on pain management, restoration of range of motion, and progressive strengthening, are critical for successful recovery and prevention of re-injury. The evidence suggests that an integrated approach, combining prevention and rehabilitation strategies tailored to the individual, is essential for minimizing NC-ACL risk and improving outcomes in affected populations. [ABSTRACT FROM AUTHOR]

Introduction: Osteoarthritis (OA) is a prevalent chronic degenerative disease, marked by a complex interplay of mechanical stress, inflammation, and metabolic imbalances. Recent studies have highlighted the potential of spermidine (SPD), a naturally occurring polyamine known for its antiinflammatory and antioxidant properties, as a promising therapeutic agent for OA. This study delves into the therapeutic efficacy and mechanistic pathways of SPD in mitigating OA symptoms. Methods: Forty Sprague-Dawley rats were randomly assigned to four groups, including the CG (sham operation), model (anterior cruciate ligament transection [ACLT], and treatment (ACLT + two different doses of SPD) groups. In vivo, correlations between OA severity and different interventions were assessed by ELISA, X-rays, CT imaging, histological staining, and immunohistochemistry. In vitro, IL-1β was used to trigger chondrocyte inflammation, and SPD's cytotoxicity was assessed in primary rat chondrocytes. Next, inflammatory markers, extracellular matrix (ECM) proteins, and pathway marker proteins were detected in chondrocytes administered IL-1β alone, SPD, or aryl hydrocarbon receptor (AhR) silencing, by qRT-PCR, Griess reaction, ELISA, Western blot, and immunofluorescence. Morphological alterations and pyroptosis in chondrocytes were examined by transmission electron microscopy (TEM) and flow cytometry. Results: Our research reveals that SPD exerts significant anti-inflammatory and antipyroptotic effects on IL-1β-treated chondrocytes and in anterior cruciate ligament transection (ACLT) rat models of OA, primarily through interaction with the Aryl hydrocarbon receptor (AhR). Specifically, SPD's binding to AhR plays a crucial role in modulating the inflammatory response and cellular pyroptosis by inhibiting both the AhR/NF-κB and NLRP3/caspase-1/GSDMD signaling pathways. Furthermore, the knockdown of AhR was found to negate the beneficial effects of SPD, underscoring the centrality of the AhR pathway in SPD's action mechanism. Additionally, SPD was observed to promote the preservation of cartilage integrity and suppress ECM degradation, further supporting its potential as an effective intervention for OA. Discussion: Collectively, our findings propose SPD as a novel therapeutic approach for OA treatment, targeting the AhR pathway to counteract the disease's progression and highlighting the need for further clinical evaluation to fully establish its therapeutic utility. [ABSTRACT FROM AUTHOR]

Background: Our study aims to examine stress–strain data of the four major knee ligaments—the anterior cruciate ligament (ACL), the posterior cruciate ligament (PCL), the medial collateral ligament (MCL), and the lateral collateral ligament (LCL)—under transient impacts in various knee joint regions and directions within the static standing position of the human body. Subsequently, we will analyze the varying biomechanical properties of knee ligaments under distinct loading conditions. Methods: A 3D simulation model of the human knee joint including bone, meniscus, articular cartilage, ligaments, and other tissues, was reconstructed from MRI images. A vertical load of 300 N was applied to the femur model's top surface to mimic the static standing position, and a 134 N load was applied to the impacted area of the knee joint. Nine scenarios were created to examine the effects of anterior, posterior, and lateral external forces on the upper, middle, and lower regions of the knee joint. Results: The PCL exhibited the highest stress levels among the four ligaments when anterior loads were applied to the upper, middle, and lower parts of the knee, with maximum stresses at the PCL-fibula junction measuring 59.895 MPa, 27.481 MPa, and 28.607 MPa, respectively. Highest stresses on the PCL were observed under posterior loads on the upper, middle, and lower knee areas, with peak stresses of 57.421 MPa, 38.147 MPa, and 26.904 MPa, focusing notably on the PCL-tibia junction. When a lateral load was placed on the upper knee joint, the ACL showed the highest stress 32.102 MPa. Likewise, in a lateral impact on the middle knee joint, the ACL also had the highest stress of 29.544 MPa, with peak force at the ACL-tibia junction each time. In a lateral impact on the lower knee area, the LCL had the highest stress of 22.279 MPa, with the highest force at the LCL-fibula junction. Furthermore, the maximum stress data table indicates that stresses in the ligaments are typically higher when the upper portion of the knee is affected compared to when the middle and lower parts are impacted. Conclusions: This study recommends people avoid impacting the upper knee and use the middle and lower parts of the knee effectively against external forces to minimize ligament damage and safeguard the knee. [ABSTRACT FROM AUTHOR]

Case: A 4-year-old girl with no relevant medical history presented with left knee swelling. Knee laxity, magnetic resonance imaging findings of anterior cruciate ligament (ACL) deficiency and discoid meniscus, and the chronicity of symptoms prompted arthroscopic ACL reconstruction and meniscal saucerization. Pain and swelling continued, and repeat arthroscopy revealed regeneration of the discoid meniscus at 18-month follow-up. Conclusion: In this unusual case, a discoid lateral meniscus regenerated after saucerization. Regeneration could be attributed to the robust vascularity of the meniscus in pediatric patients. Surgeons should counsel about the risk of recurrence after treatment of discoid meniscus. [ABSTRACT FROM AUTHOR]