Anterior Cruciate Research Articles

From Fear to Resilience: A Scoping Review of Psychological Components in Anterior Cruciate Ligament Rehabilitation.

Anterior cruciate ligament (ACL) injuries, prevalent in athletic contexts have profound physical and psychological impacts. Despite extensive research on the physiological aspects of ACL recovery, the psychological dimensions of this process have gained increased attention. This scoping review delves into the intricate landscape of psychological factors influencing ACL rehabilitation. Scoping review. A literature search across multiple databases was conducted to identify relevant published studies that provide insight into the psychological aspects of ACL recovery. This search spanned various study designs, enabling a nuanced understanding of the psychological intricacies surrounding ACL recovery. Overall, a total of 1830 unique articles were screened, of which 66 were included in this review. Our findings are further contextualized through alignment with insights from prior reviews on similar themes. Through a comprehensive analysis of diverse literature, we explore 3 key themes: psychological challenges, current rehabilitation programs, and the integration of psychological support. Psychological challenges emerged as a pervasive aspect of ACL rehabilitation, encompassing fear, anxiety, motivation, and depression. The nuanced emotional responses, particularly the fear of reinjury, impact treatment adherence and overall well-being. Contemporary rehabilitation programs revealed inconsistencies in incorporating psychological support, emphasizing the need for standardized, multidisciplinary approaches. The alignment with prior reviews in the literature reinforced the importance of psychological traits, such as knee self-efficacy, in predicting positive outcomes. This scoping review provides a comprehensive overview of psychological factors within ACL rehabilitation, highlighting the importance of tailored interventions and standardized approaches. The integration of multidisciplinary expertise emerges as crucial for optimizing patient outcomes. Our findings not only contribute to a nuanced understanding of psychological nuances in ACL rehabilitation but also offer valuable implications for clinical practice and policy development.

Epidemiology of paediatric winter sports-related injuries in France: The WINTRAUMA-1 retrospective cohort study.

To describe the epidemiology of injuries related to winter sports in patients younger than 15 years in France. We conducted a retrospective observational multicentre cohort study of patients younger than 15 years who were seen by mountain-community general practitioners for winter-sports injuries in 1999-2022. Of the 108 619 patients (mean age, 11.4 ± 2.8 years), 76 724 (70.6%), 26 186 (24.1%) and 2132 (2.0%) were injured while skiing, snowboarding and sledding, respectively. Helmet use was noted in 50 164 (46.2%) patients and increased over time but remained low among sledders. A collision was the mechanism in 12.3% of patients overall and 32.1% of sledders. The most common injuries overall were wrist fractures (48.5%), head and trunk injuries (42.3%), and anterior cruciate ligament (ACL) tears (23.7%), with wrist fractures being more common in beginners (24.7%) and head/trunk injuries and ACL tears in advanced participants (18.3% and 2.6%, respectively). Only 3699 (3.4%) patients were admitted after the general-practitioner visit, notably for leg or ankle fractures (9.5%). Winter sports-related injuries vary according to age, sex, skill level and sport. Admission rates are low but might be further decreased by better prevention. Protective measures should be tailored to each sport and individual.

Neural functions vary by return-to-sport status in participants with anterior cruciate ligament reconstruction: a retrospective cohort study using sub-bands of resting-state functional magnetic resonance

Neural functions vary by return-to-sport status in participants with anterior cruciate ligament reconstruction: a retrospective cohort study using sub-bands of resting-state functional magnetic resonance

Polydatin protects against articular cartilage degeneration by regulating autophagy mediated by the AMPK/mTOR signaling pathway.

Knee osteoarthritis (KOA) is one of the leading causes of disability. Polydatin has a potential effect on KOA treatment but the therapeutic mechanism is not clear. This study aims to investigate the therapeutic action of polydatin in KOA and its mechanism in activating autophagy via the AMP-activated protein kinase (AMPK)/mTOR signaling pathway. After a KOA rat model was established by anterior cruciate ligament transection surgery, model rats were treated with polydatin 40 mg/kg for 30 days. Subsequently, cartilage tissues were collected, and hematoxylin-eosin (HE), Safranin-O, and TUNEL staining, and western blotting were performed to evaluate the pathological damage and autophagy-related protein expression. Then, human chondrocyte C28/I2 cells were stimulated with lipopolysaccharide (LPS), and the effects of polydatin on C28/I2 cell viability, apoptosis, and autophagy-related protein expression were detected by MTT, Flow Cytometry, and western blot. In addition, an AMPK inhibitor (Dorsomorphin 2HCl) was used to probe the cell proliferation and apoptosis of polydatin-administered C28/I2 cells. Polydatin ameliorated the pathological damage in rat cartilage tissues and inhibited cell apoptosis in KOA rats. Meanwhile, in C28/I2 cells, polydatin promoted viability and reduced apoptosis. In addition, the protein expression of collagen II, LC3II/LC3I, Beclin-1, and p-AMPK/AMPK were upregulated, and p62 and p-mTOR/mTOR were downregulated by polydatin treatment. Interestingly, relative results showed that the protective effect of polydatin in LPS-stimulated-C28/I2 cells was blocked by the AMPK/mTOR inhibitor, dorsomorphin 2HCl. Our research showed that polydatin reduced apoptosis and activated autophagy both in vivo and in vitro by the AMPK/mTOR signaling pathway to protect against KOA, which provided the basis for further investigation into the potential therapeutic impact of polydatin on KOA.

A Bibliometric Analysis of the Top Cited Articles on Anterior Cruciate Ligament Reconstruction with Anterolateral Ligament Reconstruction

A Bibliometric Analysis of the Top Cited Articles on Anterior Cruciate Ligament Reconstruction with Anterolateral Ligament Reconstruction

Is an excessively high posterior tibial slope a predisposition to knee injuries in children? Systematic review of the literature.

The literature agrees that an increased posterior tibial slope (PTS) increases the risk of anterior cruciate ligament (ACL) rupture in adults. However, there is no consensus on the average normal value and it varies with growth. We carried out a systematic review of the literature to answer 4 questions faced with an increase in PTS in children: METHOD: We conducted a systematic review of the literature in accordance with PRISMA criteria. The inclusion criteria were all studies analyzing the association between increased PTS and the occurrence of knee disease in patients, the majority of whom were under 18 years of age or had immature skeletons. For each study, we recorded the demographic characteristics of the patients, the type of measurements performed, the PTS values and the association between the PTS value and the occurrence of pathology. A total of 294 studies were identified. After analysis, 11 studies were included (n = 1173 patients). Six studies examined the association between PTS and anterior cruciate ligament (ACL) rupture (n = 5) or recurrence of rupture (n = 1). Two studies investigated the association between tibial slope and proximal tibial fracture and 3 studies investigated the association between tibial slope and growth disease (Osgood Schlatter (OSD) or osteochondritis dissecans of the knee). Of the 5 ACL studies, all studies found a significant increase in PTS in patients with ACL rupture (range min 2.1 ° max 4.3 °) compared with healthy subjects. Concerning growth lesions, 3 studies found an increased PTS in patients with OSD or osteochondritis. The studies concerning fractures of the proximal end of the tibia also found an increase in PTS. This review highlighted the potential link between an abnormally high PTS value and the occurrence of knee pathologies in children, in particular ACL rupture. Children with a high PTS and an ACL rupture will require longer-term follow-up and should be warned of the greater risk of re-rupture. IV; systematic review.

Ononin delays the development of osteoarthritis by down-regulating MAPK and NF-κB pathways in rat models.

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. 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. 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. 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.

The influence of menstrual cycle phase on isokinetic knee flexor and extensor strength in female soccer players: a pilot study

ABSTRACT The prevalence of anterior cruciate ligament injury in female soccer players has been attributed to hormonal fluctuations during the menstrual cycle (MC), with injury incidence greatest during the follicular phase. Eight, eumenorrheic, collegiate soccer players (19.5 ± 0.75 years, 1.62 ± 4.90 cm, 61.12 ± 7.6 kg mean ± SD) completed eccentric knee flexor and concentric knee extensor trials at 60 and 240°·s−1 during the follicular, ovulation and luteal phases of their MC. Peak torque and corresponding angle of peak torque were maintained across all phases of the MC, irrespective of testing modality and speed (p ≥ 0.149). Strength ratios defined using peak torque were also not sensitive to MC phase (p ≥ 0.933). However, Functional Range in eccentric knee flexion was significantly lower during the follicular phase (p = 0.017), at both testing speeds. This supports epidemiological observations but highlights the importance of analysing isokinetic data beyond the peak of the strength curve. Interpretation of isokinetic data should therefore focus on points of “weakness” as opposed to maximum strength, whilst (p)rehabilitative strategies should consider strength through range of motion, and at different speeds. Eccentric hamstring strength was observed to decrease significantly at the higher speed, contrary to observations in elite male players, and potentially reflecting a differential training adaptation.

Variation In Response to Limb Loading Instruction on Knee Mechanics During Squatting in Early Recovery Following Anterior Cruciate Ligament Reconstruction.

On average, individuals in early recovery following anterior cruciate ligament reconstruction (ACLr) improve limb loading symmetry (LLS) with instruction to equalize weight distribution between limbs during squats. However, the extent to which these instructions improve knee extensor loading symmetry (KLS) or reduce intra-limb compensations is not known. Determine how limb loading instructions influence knee and intra-limb loading in individuals 3-4 months post-ACLr and to explore variations in responses across individuals. Controlled Laboratory study. Research Laboratory. Individuals 109.4 days (18.2 days) post-ACLr (n=20) and healthy matched controls (CTRL; n=19). Participants performed double limb squats in natural (N; no instruction) and instructed (IN; instruction to evenly distribute weight between limbs) conditions. Between limb and knee loading symmetry were calculated as the ratio of vertical ground reaction force and knee extensor moment impulse, between surgical(Sx):matched and non-surgical(NSx):matched limbs (ACLr:control), respectively. Intra- limb hip/knee (H/K) extensor loading distribution was calculated in Sx:matched limbs. LLS (N: 0.86; IN: 0.93, P < 0.001; ES:0.83) and KLS (N: 0.54; IN: 0.62, P=0.007; ES:0.67) improved with instruction in the ACLr group with no change in CTRL. H/K ratio did not change for either group. K-means clustering, considering natural and change (natural- instructed) in LLS, KLS, and H/K ratio, described response to instruction across three clusters: 1) ACLr: n=3; CTRL: n=9, were symmetrical in both conditions, 2) ACLr: n=14, showed some improvement in symmetry, 3) ACLr: n=3, only improved LLS. Average data suggests that weightbearing instruction improved LLS to within 7%, but a 38% knee loading deficit remained, and intra-limb compensation did not improve. Data- driven clusters indicate that three ACLr subjects were similar to controls, fourteen improved LLS, KLS and H/K distribution, and three only improved LLS with worsening KLS and H/K.

Evaluation of the relationship between non-contact anterior cruciate ligament rupture and eminential morphometry: a cross-sectional and MRI based study

BackgroundThe 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.MethodsKnee 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.ResultsIn 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.ConclusionsA 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 registrationNot applicable.

Evaluation of Lateral and Medial Parts of the Hamstring Muscle Fatigue Symmetry in Professional Footballers Cleared to Play After ACL Reconstruction

Objectives: Rupture of the anterior cruciate ligament (ACL) is a severe injury common in sports. It also has a high rate of re-injury. The aim of this work was to assess hamstring muscle fatigue in active football players after ACL reconstruction who were cleared to play and to determine symmetry between the lateral and medial hamstring muscles. Methods: In professional football players post ACL reconstruction (n = 25) and non-injured players (n = 26), the bioelectrical activity of the medial (biceps femoris—BF) and lateral (semimembranosus and semitendinosus—SEM) hamstring muscles was measured during 60 s of isometric contraction. The fatigue variables were calculated using the Continuous Wavelet Transform (CWT) tool. Results: The football players following ACL reconstruction demonstrated significant asymmetry in fatigue of the lateral and medial hamstring muscles, with greater fatigue in the SEM compared to the BF muscle. Moreover, in those after reconstruction, the changes are more pronounced, with higher muscle fatigue in both limbs (they have lower MDF than non-injured players) and more severe SEM muscle insufficiency (noted in both limbs but with greater intensity in the non-operated one). Conclusions: The higher SEM muscle fatigue observed in this study influenced the lateral-to-medial activation ratio within the hamstring muscle, which may be a probable cause of this muscle’s insufficiency in laterally stabilizing the knee in the frontal and transverse plane. Furthermore, the hamstring muscles after reconstruction were more fatigued in both limbs, which may be another risk factor for ACL graft rupture. Therefore, increased fatigue in specific hamstring muscles may indicate the direction in which knee stabilization is compromised due to ACL overload. A muscle that becomes fatigued and inefficient more quickly also becomes ineffective in performing its function sooner, which can lead to increased overloading forces acting on the ACL graft.

MCL augmentation using a peroneus longus split tendon autograft satisfactorily restores knee stability with no impairment in foot function and with a low failure rate for concurrent ACL reconstruction.

Addressing grade 2 and 3 medial-sided instabilities during anterior cruciate ligament (ACL) reconstruction is crucial to reduce the risk of ACL graft failure. This study introduced a minimally invasive, medial collateral ligament (MCL) augmentation technique using a peroneus longus split tendon autograft, which was fixed to the femoral deep MCL insertion and tibial superficial MCL insertion. This prospective, longitudinal, single-centre case series included patients who underwent MCL augmentation concurrent with primary or revision ACL reconstruction due to anteromedial instability. Preoperatively and at 1-year follow-up, clinical examinations, such as rolimeter test of anterior tibial translation and medial instability, knee (International Knee Documentation Committee subjective knee form [IKDC], Lsyholm, Knee Injury and Osteoarthritis Outcome Score [KOOS]) and foot function scores (American Orthopaedic Foot and Ankle Society score [AOFAS]) and complications, were analyzed. Thirty-one patients with a mean follow-up of 13.5 ± 2.6 months and a mean age of 27.8 ± 9.6 years were included. The side-to-side difference for anterior tibial translation significantly improved from preoperative to 1-year follow-up with an ACL reconstruction failure rate of 6.5%. No patient retained a grade 2 or 3 medial instability on valgus stress testing with 30° flexion. Significant improvements from preoperative to 1-year postoperative follow-up were observed in knee function scores: IKDC (48.9 ± 26.9- 71.3 ± 11.5, p < 0.001) and Lysholm (59.9 ± 28.5-80.5 ± 11.2, p = 0.002) as well as KOOS pain, ADL, sport and QoL, each reaching the respective minimal clinically important difference values. The foot function score AOFAS showed no significant impairment (100 ± 0-99.3 ± 2.5, p = 0.250). Complications included cyclops lesions of ACL reconstruction in three patients. At 1-year follow-up, MCL augmentation using a peroneus longus split tendon autograft for patients simultaneously undergoing ACL reconstruction satisfactorily restores knee stability, has a low ACL reconstruction failure rate and does not significantly impair foot function. Level IV therapeutic study; case series.

Arthroscopic meniscus transplant using autologous semitendinosus with bone marrow aspirate-derived fibrin clot along with anterior cruciate ligament reconstruction – A case report

Subtotal and total meniscectomy is known to advance osteoarthritis in patients. Meniscus transplant using semitendinosus autograft is a viable option in young patients. We have presented the early follow-up, along with technical video, for arthroscopic meniscus transplant with autologous semitendinosus graft with bone marrow aspirate-derived fibrin clot along with anterior cruciate ligament (ACL) reconstruction, in the primary surgery, in a patient of ACL tear along with near-complete loss of medial meniscus due to auto-meniscectomy. The patient showed good functional and radiological outcome at 9 months.

Comparison of blood flow restriction training rehabilitation and general rehabilitation exercise after anterior cruciate ligament reconstruction: A meta-analysis of randomized controlled trials.

Blood flow restriction training (BFRT) has been found to reduce quadriceps atrophy and weakness after anterior cruciate ligament (ACL) surgery. However, the clinical benefit of BFRT as compared to general rehabilitation exercise (GRE) alone remains uncertain. This study aimed to compare the effects of BFRT and GRE on ACL reconstruction rehabilitation through a meta-analysis of randomized controlled trials. PubMed, Web of Science, EMBASE, Elsevier and Biosis were searched for randomized controlled trials comparing BFRT and GRE following ACL reconstruction. Primary outcomes included muscle strength (extensor and flexor muscle general strength), Lysholm score, the International Knee Documentation Committee (IKDC) score, extensor muscle torque (peak torque and average torque) and muscle cross-sectional area (CSA). The secondary outcomes included a range of motion (ROM), pain, Y-balance and the Patient-Reported Outcomes Measurement Information System (PROMIS). Thirteen randomized controlled trials involving 376 participants were included. The change in muscle strength (Mean difference, MD: 12.96, 95% confidence interval, [95% CI]: 7.02-18.91, heterogeneity, I2 = 39%), Lysholm score (MD: 9.41, 95% CI: 8.93-9.88, I2 = 40%) and IKDC score (MD: 9.88, 95% CI: 0.57-19.19, I2 = 87%) of the BFRT group were superior to that of the GRE group at the time of last follow-up. However, no significant difference was found between the BFRT and the GRE groups regarding the change in muscle CSA, ROM, extensor muscle torque, pain score, Y-balance and PROMIS. BFRT seems to perform better than GRE in terms of functional improvement and muscle strength following ACL reconstruction, but there seems to be no significant difference between them in terms of joint mobility, pain relief, stability improvement and patient's perception of their disease and treatment. Level II.

Tensile Strength of the Achilles Tendon Allograft: A Comparative Study of Graft Preparation Technique

Background/Objectives: The Achilles tendon is a popular allograft option for anterior cruciate ligament (ACL) reconstruction. Structurally, the tendon is known to have a 90-degree rotational fiber track. Preparation techniques, with this consideration, may influence the strength of the graft. This study aims to assess the tensile strength of a novel Achilles tendon allograft harvest procedure following the rotational fiber track. Methods: Both Achilles tendons were harvested from formalin-embalmed cadavers [(n = 20), male n = 13, female n = 7, average age = 70]. Ten cadavers had the right Achilles as the control and the left Achilles as the fiber track sample; 10 cadavers had the opposing designation. Tensile strength was tested utilizing a Bose machine. An unpaired t-test was used to compare data across groups. Results: The average ultimate load for the control group was 874.17 N, with an average elastic stiffness of 76.01 N/mm. The ultimate load for the fiber track group was 807.84 N, with an average elastic stiffness of 64.75 N/mm. No statistically significant difference (p = 0.21) was determined between the average ultimate loads or elastic loads (p = 0.18) across groups. Conclusions: These data suggest that the rotational fiber track method of Achilles allograft has consistent tensile strength and elastic stiffness as compared to the common harvest procedure. The rotational fiber track method for ACL harvesting is a viable alternative option to the common harvest procedure for usage in an ACL reconstruction.

Relationship between Cognitive Demands and Biomechanical Indicators Associated with Anterior Cruciate Ligament Injury: A Systematic Review.

Anterior cruciate ligament (ACL) injury during contact sports has a high incidence that has not been reduced despite the immense resources devoted to understanding its aetiology. A neurocognitive approach could increase knowledge of the mechanisms contributing to ACL injury enabling practitioners to address and minimise future risk. To systematically review the influence of manipulating cognitive demands during motor tasks (i.e. degree of uncertainty) on biomechanical variables associated with ACL injury risk. A systematic review was performed according to the Cochrane Handbook for Systematic Reviews of Interventions by searching the major sporting electronic databases. The search strategy included four groups of terms and was conducted by two authors independently. All studies were screened using unique inclusion criteria, with the included studies assessed for risk of bias. Twenty-five studies were identified from 2031 records and included into the review process. During the experimental conditions where cognitive demands were higher, most biomechanical indicators associated with a greater risk of ACL injury during landing and cutting tasks were significantly enhanced compared with conditions with low or no cognitive demands. An increase in task complexity through cognitive load significantly leads to changes in mechanisms associated with ACL injury during single-leg landings and cutting movements. Consequently, coaches and exercise professionals should consider inclusion of dual-task paradigms or uncertainty during injury risk assessment scenarios and injury prevention programs to help identify athletes at risk of ACL injury and reduce ACL injury frequency. This protocol was registered in the PROSPERO database ( https://www.crd.york.ac.uk/PROSPERO ) in May 2022, with the registration number CRD42022315795.

The Impact of Anterior Cruciate Ligament Tear on Player Performance and Longevity in La Liga League Soccer Players

AbstractAnterior cruciate ligament (ACL) rupture is among the most studied sports injuries. We investigate the impact of ACL reconstruction (ACLR) on performance and longevity in La Liga to elucidate performance parameters impacted after surgery in professional soccer players and variables impacting return-to-play (RTP).Demographic and performance data for La Liga players with ACLR between 1993 and 2020 were collected three seasons before and after injury and compared with two healthy controls. Analysis was conducted between and within ACLR and control groups. Pearson's correlation coefficients and a multiple linear regression model analyzed relationships between demographic variables and RTP.After exclusion, 23 professional soccer players were identified for the ACLR group. One year after index, ACLR had lower goals, shots on-target, assists, pass percentage, tackles, tackle success percentage, blocks, and clearances compared with control (p &lt; 0.05). Two years after index, ACLR had lower assists, pass percentage, and tackle success percentage than control (p &lt; 0.05). Three years after index, ACLR had fewer matches and blocks versus control (p &lt; 0.05). Pearson's correlation showed a positive correlation between experience and RTP (p = 0.001). Multiple linear regression found RTP to increase 32.66 days for each additional year of experience (p &lt; 0.001).With performance metrics showing significant decreases up to 2 years post-ACLR but largely recovering within 3 years of RTP, results support that soccer players undergoing ACLR eventually recover to preinjury levels of play. Players should be counseled on initial declines in performance metrics the first few years after RTP.

Intralimb Coordination Pattern of the Lower Limbs in Male Athletes With Allograft and Autograft Anterior Cruciate Ligament Reconstruction During Landing

Background and Objectives: Two common choices exist for anterior cruciate ligament (ACL) reconstruction, autograft and allograft. Hamstring tendon autografts and soft-tissue allografts are commonly used for ACL reconstruction. The outcomes between these two grafts are controversial. This research aims to quantify and compare lower limb joint coordination between two ACL reconstruction graft options and healthy individuals. Methods: Sixty-one athletes were enrolled after ACL reconstruction surgery (allograft, n=22; autograft, n=18). Furthermore, twenty-one healthy athletes were considered in the control group. The inclusion criteria included unilateral anterior cruciate ligament reconstruction surgery with allograft and autograft methods, male athletes with a minimum of 9 months and a maximum of two years since their surgery, successfully passing a series of quadriceps and hamstring strength tests and distance jumping before entering sports-specific activities under the supervision of a sports physiotherapist, and returning to pre-injury sports activities. Results: Autograft was not statistically different from matched healthy limbs in terms of joint coordination variability and magnitude (P&gt;0.05). However, the magnitude of joint coordination was superior to the allograft group compared to the autograft reconstructed ACL (P&lt;0.05). Conclusion: Although our result reported no significant difference between groups in joint coordination variability, having an insight into coordinative function after ACL reconstruction will help develop postoperative rehabilitation programs as well as minimize the re-injury risk among patients. We also suggest that scholars should conduct more robust trials with valid research designs to control the results of ACL reconstruction comparison with autograft and allograft.

Musculoskeletal Tissue Asymmetries Following Anterior Cruciate Ligament Reconstruction

OBJECTIVE: To compare musculoskeletal tissue asymmetries between those who had undergone ACLR and non-surgical controls, and to evaluate the influence of sex on asymmetries and perceptions of knee function in ACLR patients. DESIGN: Cross-sectional cohort analysis. METHODS: Individuals (female n=11, male n=11) with a history of ACLR and matched controls (female n=10, male n=9) completed Dual-energy X-ray Absorptiometry (DXA) scans to measure lower-body bone mineral content (BMC), Fat%, and lean mass (LM). Perceptions of knee function were captured via the International Knee Documentation Committee (IKDC) instrument and inter-limb asymmetry indices (AI%) were calculated for each DXA outcome. Surgical groups and sexes were compared using independent t-tests ( p&lt;0.05) and Cohen’s effect sizes ( d). Additionally, Pearson’s Correlation Coefficients evaluated the association between AI% and IKDC scores. RESULTS: The ACLR group showed greater lower-body asymmetries, specifically less BMC and LM and greater Fat% in the ACLR limb ( p≤0.044; d=0.63–0.87). ACLR group sex comparisons found that females had lower IKDC scores, greater asymmetries for BMC and LM ( p≤0.027, d=0.40–0.74), and these asymmetries were negatively correlated with IKDC scores (all r≥0.755; p≤0.007) while males demonstrated no such correlations. CONCLUSIONS: Individuals with a history of ACLR had persistent musculoskeletal tissue asymmetries that favored the non-surgical leg. The asymmetries were greater in female versus male patients and were associated with lower perceptions of knee function. Thus, musculoskeletal imaging may provide complementary information to the current standard of care during ACLR rehabilitation.

Decoding the mechanical characteristics of the human anterior cruciate ligament entheses through graduated mineralization interfaces

The anterior cruciate ligament is anchored to the femur and tibia via specialized interfaces known as entheses. These play a critical role in ligament homeostasis and joint stability by transferring forces, varying in magnitude and direction between structurally and functionally dissimilar tissues. However, the precise structural and mechanical characteristics underlying the femoral and tibial entheses and their intricate interplay remain elusive. In this study, two thin-graduated mineralization regions in the femoral enthesis (~21 μm) and tibial enthesis (~14 μm) are identified, both exhibiting distinct biomolecular compositions and mineral assembly patterns. Notably, the femoral enthesis interface exhibits progressively maturing hydroxyapatites, whereas the mineral at the tibial enthesis interface region transitions from amorphous calcium phosphate to hydroxyapatites with increasing crystallinity. Proteomics results reveal that Matrix Gla protein uniquely enriched at the tibial enthesis interface, may stabilize amorphous calcium phosphate, while C-type lectin domain containing 11 A, enriched at the femoral enthesis interface, could facilitate the interface mineralization. Moreover, the finite element analysis indicates that the femoral enthesis model exhibited higher resistance to shearing, whereas the tibial enthesis model contributes to tensile resistance, suggesting that the discrepancy in biomolecular expression and the corresponding mineral assembly heterogeneities collectively contribute to the superior mechanical properties of both the femoral enthesis and tibial enthesis models. These findings provide novel perspectives on the structure-function relationships of anterior cruciate ligament entheses, paving the way for improved management of anterior cruciate ligament injury and regeneration.