ACL Reconstruction Research Articles

Magnetic Resonance Imaging Can Predict Hamstring or Quadriceps Tendon Autograft Diameter in Pediatric or Adolescent Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Insufficient graft diameter is an important factor that contributes to failure rates after anterior cruciate ligament reconstruction (ACLR). Although modalities, such as magnetic resonance imaging (MRI), have been well investigated in the adult population to predict graft diameter preoperatively, it is unclear whether similar strategies can be used in the pediatric population. This review aims to evaluate the utility of MRI in the preoperative estimation of autograft parameters in pediatric or adolescent patients undergoing ACLR. Three databases were searched on January 31, 2024. The authors adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Revised Assessment of Multiple Systematic Reviews guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, graft characteristics, MRI imaging techniques, and statistical analyses correlating MRI parameters with graft length or diameter were recorded. Five studies consisting of 450 patients were included in this review (48.4% females). The mean (SD) age at ACLR was 14.7 (6.8) years. Three studies using hamstring tendon (HT) autografts found that combined semitendinosus and gracilis tendon cross-sectional area (ST+GT CSA) were able to predict graft diameter. One study reported an ST+GT CSA cutoff of 31.2mm2 to have an 80% and 74% sensitivity and specificity, respectively, in predicting HT autograft diameter above 8mm. Two studies using quadriceps tendon (QT) autografts found that tendon thickness on sagittal MRI view was able to predict graft diameter. One study reported a QT cutoff of 6.7mm to have 97.5% and 46.6% sensitivity and specificity, respectively, in predicting the diameter of the QT graft to be above 8mm. Associations between MRI parameters and graft length were not reported. Although there is limited evidence, ST+GT CSA and QT thickness on sagittal view on MRI can be used to predict intraoperative HT and QT autograft diameter, respectively, in pediatric or adolescent ACLR. Future investigations should investigate correlations between imaging parameters and graft length, especially when using QT autografts in the pediatric population. Level III.

Limb dominance influences landing mechanics and neuromuscular control during drop vertical jump in patients with ACL reconstruction.

The purpose of this study was to compare the interlimb biomechanical differences in patients who had undergone anterior cruciate ligament reconstruction (ACLR) in either dominant (ACLR-D) or nondominant (ACLR-ND) limbs and healthy controls (CON) during drop vertical jump (DVJ) task. To investigate whether the dominant or nondominant limb influences the risk of re-injury in ACLR patients. Thirty-three ACLR patients were divided into ACLR-D and ACLR-ND groups according to whether the surgical limb was dominant or nondominant. Seventeen healthy individuals were selected as the CON group. Three-dimensional kinematic data, ground reaction force (GRF) data, and surface electromyographic (EMG) data from the bilateral lower limbs of all participants were collected during the DVJ task. Two-way repeated-measures ANOVAs (limb × group) were performed on the variables of interest to examine the main effects of limb (dominant vs. nondominant) and group (ACLR-D, ACLR-ND, and CON), as well as the interaction between limb and group. The nonsurgical limbs of ACLR group had significantly greater knee valgus angles, knee extension and valgus moments, peak posterior GRF (PPGRF), and peak vertical GRF (PVGRF) compared to the surgical limbs. The nonsurgical limbs of ACLR-ND patients demonstrated significantly greater knee extension and valgus moments, greater PPGRF and PVGRF, and reduced muscle activity in the vastus medialis and vastus lateralis compared to the CON group. The ACLR patients had reduced muscle activity in the quadriceps of the surgical limb and the hamstrings of the bilateral limbs compared to controls. The nonsurgical limbs of ACLR patients may suffer an increased risk of ACL injury due to altered landing mechanics and neuromuscular control strategies compared to the surgical limbs. Additionally, limb dominance influences movement patterns and neuromuscular control during DVJ task, the nonsurgical limbs of the ACLR-ND might be at higher risk of ACL injury compared to the ACLR-D group.

The Relationship Between Active Coping Skills and Self-Reported Knee Function in Individuals with Anterior Cruciate Ligament Reconstruction.

Individuals with anterior cruciate ligament (ACL) injury commonly experience injury related stressors which can adversely impact subjective knee function after ACL reconstruction (ACLR). Due to the positive effect of active coping skills on perceived stressors, use of such strategies may influence clinical outcomes in individuals with ACLR, such as self-reported knee function. However, it is unknown whether active coping skills are associated with self-reported knee function in this population. Examine the relationship between active coping skills and self-reported knee function in individuals with ACLR. Cross-Sectional Study. Laboratory. Forty-five participants (34 females; age=20.0[3.3] years) 4-months to 5-years post-unilateral ACLR (time since ACLR=12.0[16.0] months). The Athlete Coping Skills Inventory (ACSI) Confidence and Achievement Motivation (ACSI Confid), Goal Setting/Mental Preparation (ACSI Goal/Prep), and Coping with Adversity (ACSI Coping) subscales were used to measure active coping skill facets. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to measure self reported knee function across 5 subscales: pain (KOOS-Pain), symptoms (KOOS-Symptoms), activities of daily living (KOOS-ADL), quality of life (KOOS-QOL), and sports/recreation (KOOS-Sport). Partial Spearman's correlations were used to examine relationships between active coping skills and self-reported knee function after controlling for time since ACLR and age. Moderate positive correlations were observed between the ACSI Confid and KOOS Pain (r=0.493, P=0.001), ACSI Confid and KOOS-QOL (r=0.505, P<0.001), ACSI Confid and KOOS-Sport (r=0.422, P=0.007), and ACSI Goal/Prep and KOOS-Pain (r=0.441, P=0.004). Weak positive correlations were observed between the ACSI Goal/Prep and KOOS-ADL (r=0.373, P=0.018) and ACSI Goal/Prep and KOOS-QOL (r=0.374, P=0.017). Individuals with ACLR who exhibited greater active coping skill facets reported better knee-related function. Assessing active coping skills among individuals with ACLR and poor self-reported knee function may provide clinicians with insight into the role of coping in perceived function and potential treatment approaches.

Quadriceps Strength Testing Practices & Barriers During Return to Sport from ACL Reconstruction: A Survey of Collegiate Athletic Trainers.

Quadriceps strength is a key outcome for guiding rehabilitation and return to sport-specific activities after ACL reconstruction (ACLR) surgery. 1) Describe the quadriceps strength testing practices and barriers college athletic trainers (ATs) are using and experiencing when returning patients to sport-specific activities after ACLR. 2)Compare testing methods between college ATs working in the National Collegiate Athletic Association (NCAA) Division I setting and other college settings. Cross-sectional. Online survey. 243 full-time collegiate ATs who had primarily overseen/directed an ACLR rehabilitation in the past five years (age: 34.8±10.7, years of AT practice: 11.7±9.3, NCAA division I setting: 56%). Our survey included four sections: Demographics, General ACLR rehabilitation practices, Quadriceps strength testing methods & criteria, and Quadriceps strength testing barriers. Knee muscle strength was the most common (98%) outcome collegiate ATs use when determining whether an ACLR patient is ready to progress to sport-specific activities. Manual muscle testing (MMT) was the most used testing method (57%), followed by isokinetic dynamometry (IKD) (48%), repetition max (RM) testing (35%) and handheld dynamometry (HHD) (22%). Most ATs (63-64%) used >90% side-to-side symmetry as their return to sport-specific activities criteria. Lack of equipment needed (83%), lack of financial means (28%), and lack of training/education (20%) were the barriers that most limited ATs use of IKD testing, the gold-standard testing method. Compared to ATs in other settings, a greater proportion of ATs working in the NCAA Division I setting used IKD testing (65% vs 28%) and a smaller proportion used MMT (47% vs 70%). While almost all college ATs considered knee muscle strength an important outcome to assess when returning patients to sport-specific activities after ACLR, quadriceps strength testing practices were highly variable among ATs and may be impacted by access to necessary resources.

Hop to It! A Systematic Review and Longitudinal Meta-analysis of Hop Performance After ACL Reconstruction.

Hop testing is widely used by clinicians to monitor rehabilitation and decide when to return to sport following anterior cruciate ligament reconstruction (ACLR); however, the trajectory of long-term hop performance has not been summarised. To investigate hop performance change over time after ACLR. Systematic review with longitudinal meta-analysis. MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SPORTDiscus to 28 February 2023. Studies with ≥ 50 participants following primary ACLR, with mean participant age of 18-40years, reporting a quantitative measure of hop performance (e.g. single forward hop distance). Results had to be reported for the ACLR limb and compared with (1) the contralateral limb (within person) and/or (2) an uninjured control limb (between person). We included 136 studies of 23,360 participants. Performance was similar across different hop tests, with steep initial improvements in within-person symmetry, tailing off after 18-24months. ACLR limb hop performance was 5-10% lower compared with the contralateral limb at 1year post-surgery, with largest deficits observed for vertical hop [87.0% contralateral limb (95% CI 85.3-88.8) compared with single forward hop 93.8% (95% CI 92.8-94.9)]. By 3-5years, results were similar between ACLR and contralateral limbs. There were limited data for between-person comparisons (n = 17 studies). Exploratory analyses showed deficits in all forward hopping tests to be very strongly correlated with each other [e.g. single forward and triple hop rho = 0.96 (95% CI 0.90-0.99)], though there was discordance in the relationship between single forward hop and vertical hop performance [rho = 0.27 (95% CI - 0.53 to 0.79)]. Hop performance is comparable to the uninjured limb by 3-5years post-ACLR, with the greatest deficits in within-person symmetry present in vertical and side hop tests. Assessment of hopping in multiple planes and comparison with uninjured controls, may provide the most complete evaluation of functional performance.

C-reactive Protein Levels After Anterior Cruciate Ligament Reconstruction.

Introduction Understanding standard changes in C-reactive protein (CRP) after Anterior cruciate ligament reconstruction (ACLR) is important for early detection of septic arthritis. Methods We conducted a prospective two-center comparative study to clarify changes in postoperative CRP levels after ACLR, as well as factors that influence the changes, in a large sample of Asian patients. A total of 439 ACLR cases were included in this study. CRP tests were performed before and one, seven, and 14 days after ACLR. Results The mean CRP level was 0.06 ± 0.19 mg/dl (range: 0-2.69) preoperatively, increased to 0.54 ± 0.58 (range: 0-4.38) mg/dl at one day postoperatively and 0.92 ± 1.22 (range: 0-11.48) mg/dl at seven days postoperatively, and decreased to 0.23 ± 0.35 (range: 0-3.11) mg/dl at 14 days postoperatively. Multivariate multiple regression analysis revealed that sex, BMI, and which facility the surgery was performed significantly affect CRP levels after one day postoperatively, and sex, BMI, and age significantly affect CRP levels after seven days postoperatively. Only sex was found to significantly affect CRP levels at 14 days postoperatively. Conclusion The present study provides a standard change in CRP after ACLR in a sufficient number of patients without postoperative complications, which would be helpful to rule out the complications. Moreover, the multivariate analysis revealed that sex, age, BMI, and facility are factors that significantly affect CRP levels after ACLR.

Analysis of Limb Loading and Lower Extremity Strength Recovery Across Time After Anterior Cruciate Ligament Reconstruction.

Evidence as to how patient thigh muscle strength and limb loading (LL) during a squatting task recovers throughout rehabilitation after anterior cruciate ligament reconstruction (ACLR) is lacking. Patients will improve LL and strength throughout rehabilitation. Changes in LL and strength over time will be positively correlated. Prospective cohort study. Level 3. A total of 60 participants (28 male/32 female; age, 22.5 ± 9.35 years) participated in 2 visits post-ACLR, assessing LL and strength. Using an instrumented pressure mat, patients completed 3 sets of 3 repetitions of bodyweight squats. Peak force (N), unilateral cumulative load (%), and quadriceps and hamstring isokinetic peak torque (N·m) were calculated and recorded bilaterally. LL and peak torque were compared over time and between limbs. A significant limb-by-time interaction was observed for LL peak force (N), where patients underloaded the ACLR limb at visit 1 compared with the contralateral limb (P < 0.01). Patients increased their ACLR LL across visits (P = 0.04). A limb-by-time interaction for quadriceps peak torque (N·m) was observed where the ACLR limb increased peak torque across visits (P < 0.01); however, strength deficits persisted at visit 2 (P < 0.01) when compared with the nonoperative limb. Weak correlations were observed between all change scores metrics (r, 0.20-0.25). Patients recovering from ACLR exhibited more symmetric loading during a squatting task and improved their lower extremity strength over time. Changes in strength were not related to changes in LL during a squatting task over time. Squatting tasks are safe and easily implemented throughout ACLR recovery. As changes in functional LL and strength recovery are not related, both should be considered in serial postoperative testing for more comprehensive function and strength assessments.

Application of blood flow restriction training in lower limb rehabilitation

With the popularity of national fitness campaigns, sports injuries, especially lower limb injuries such as anterior cruciate ligament tears and ankle sprains, are increasing year by year. There are limitations in traditional treatment such as muscle atrophy. In recent years, the blood flow restriction training method (BFRT) which simulates high-intensity exercise with low intensity and limits arterial and venous blood flow to promote muscle growth and strength enhancement, has drawn attention as a novel approach to rehabilitation. This article reviews the application of BFRT in the rehabilitation of lower limb injuries, discusses its effects on muscle function, pain management and quality of life, and evaluates its safety and prospects for clinical application. BFRT reduces mechanical stress, relieves pain, improves endurance and aerobic capacity, and improves cardiovascular function. However, there are discomfort and potential risks, such as muscle injury and thrombosis, which require individualised adjustments and standardised training. BFRT has shown positive result(reducing pain &amp;oedema and improving function)s in rehabilitation of ACL reconstruction (ACLR) and chronic ankle instability (CAI). In addition, BFRT has been shown to aid in the functional recovery of the lower extremity in patients with Achilles tendon injuries and strokes. Despite the positive effects of BFRT, relevant studies have problems such as small sample sizes and non-uniform parameters. BFRT is considered a safe training modality, but contraindications should be examined before clinical application. Future research endeavours should investigate the impact of BFRT in many rehabilitation contexts and enhance tailored rehabilitation strategies. In order to maximize the therapeutic benefit, a rehabilitation training program should be developed and refined with a minimum effective dose based on the quantification of the in vivo physiological response to BFRT. The identification of the optimal prognostic approach will help to advance the standardisation of BFR treatment methods.

ANTERIOR CRUCIATE LIGAMENT RUPTURE DISGUISED AS PATELLAR INSTABILITY: A COMMON MISS

Patellar dislocation is a common presentation with a clear management pathway. Sometimes, however, what a patient experiences as the patella dislocating may, in fact, be ACL insufficiency.We reviewed case notes and imaging of 315 consecutive ACL reconstructions, collecting data on the date and mechanism of injury, time to MRI, and reconstruction. We noted cases initially diagnosed as patellar dislocation.25 of 315 (7.9%) patients were initially diagnosed with a patellar dislocation. Subsequently, however, MRI scans revealed no evidence of patellar dislocation and instead showed ACL rupture with pathognomonic pivot-shift bony oedema. The false patella dislocation group were 32% female and had an average age of 25; the rest of the group average age was 27.1 and there were a lower proportion of females; 21%. The false patella instability patients had a median waiting time of 412 days from injury to operation (range: 70-2445 days), compared to 392 days (range: 9 – 4212 days) for rest of the patients. 5 of the remaining 290 had MRIs showing patella oedema with medial patello-femoral ligament injury in addition to their ACL rupture.From our literature search this is a new finding which shows that ACL rupture can present with symptoms suggestive of patellar dislocation. These findings raise the risk that there are a group of people who have been diagnosed with patellar instability who instead have ACL insufficiency and so are at risk of meniscal and chondral damage. Further research should analyse those diagnosed with patellar instability to quantify missed ACL injuries.

Tale of quadriceps and hamstring muscle strength after ACL reconstruction: a systematic review with longitudinal and multivariate meta-analysis

ObjectiveThis study aimed to investigate how knee extensor and flexor strength change over time after anterior cruciate ligament reconstruction (ACLR).DesignSystematic review with longitudinal meta-analysis.Data sourcesMedline, Embase, CINAHL, Scopus, Cochrane CENTRAL...

Right knee ACL, PCL and MCL reconstruction with sports-related anxiety

Introduction: JM, a 20-year-old male professional ice hockey player, presented with a 2-week history of lack of range of motion, weakness, and pain in his right knee, after a 2-year post-medical collateral ligament repair of the right knee and 3 year-post anterior cruciate ligament, posterior cruciate ligament and medial collateral ligament reconstruction of the right knee. Case Description: In the course of history taken, it was revealed that 5 months prior to admission the patient had been informed by a psychiatrist that he had sport-related anxiety. With an unremarkable psychiatric history prior to age 18, the competitive nature of his sports career in addition to financial pressure may have contributed to his sports-related anxiety. His examination findings were consistent with a diagnosis of complete tears of the right anterior cruciate ligament and posterior cruciate ligament along with grade III medial collateral ligament injury. Discussion: The biopsychosocial model was used to explicate JM's case. JM's current injuries prompted reconstruction of the anterior cruciate, posterior cruciate, and medial collateral ligaments. Psychologically, JM's sports-related anxiety is not a rare phenomenon as recent studies have discovered an increased risk of sports-related anxiety amongst young professional athletes. Sports-related anxiety, along with competitive trait anxiety, may be factors that contribute to sports injury occurrence. Other psychological stressors can add to sports-related or competitive trait anxiety, further increasing the risk of sports injury reoccurrence. Summary: JM was admitted for a right knee open medial collateral ligament repair with internal bracing, anterior cruciate ligament reconstruction, posterior cruciate ligament reconstruction, and platelet rich plasma injection. As part of a holistic patient-centered treatment plan, a referral to psychiatry was made to address JM's sports-related anxiety with the goal of decreasing future risk of sports injury. Patient's Consent Obtained: Yes

Prospective comparative study between peroneus longus tendon autograft and hamstring tendons autograft in single bundle ACL reconstruction

ABSTRACT Background ACL reconstruction is often regarded as the most effective approach of restoring knee stability. Several graft possibilities are available, including (BPTB), four-strand hamstring autografts, quadriceps tendon, and peroneus longus tendon. Each has both advantages and cons. This study compares the effectiveness of peroneus longus and hamstring tendon autografts for single bundle ACL restoration. Patients and Methods The study involved 60 patients. Thirty of them had their torn anterior cruciate ligaments reconstructed arthroscopically using hamstring tendons, while the other 30 had their ACLs managed arthroscopically with peroneus longus tendon. The follow-up period lasted at least 12 months. Patients were assessed using IKDC score and Lysholm score. Ankle function was assessed using AOFAS score. Results There was a statistically significant difference in preoperative and postoperative range of motion improvement in each group as an IKDC score item. However, no statistically significant difference existed between both groups. A statistically significant change in Lysholm scores preoperatively and postoperatively in each group was detected, but there was no statistical difference between groups 1 and 2, either in terms of improvement or percentage improvement. The AOFAS score was used also to assess for any donor site morbidity. No significant difference was detected between both ankles range of motion and no ankle joint dysfunction or problems with sports activities. Conclusion The current study found that the PL tendon autograft might be considered a safe, effective and a technically easy graft option for ACLR. The research shows no substantial difference in postoperative knee stability or graft failure rate between hamstring and peroneus tendons.

Superior Biological Healing of Hamstring Autografts Compared with Tibialis Allografts after Anterior Cruciate Ligament Reconstruction: A Propensity Score Matching Analysis Based on Second-Look Arthroscopy.

Background and Objectives: Remodeling and healing of the graft are crucial processes for long-term graft survival after anterior cruciate ligament reconstruction (ACLR). However, few studies have objectively evaluated the differences in graft healing between autografts and allografts. This study aimed to compare the status of the anterior cruciate ligament (ACL) grafts between hamstring tendon (HT) autografts and tibialis anterior tendon (TAT) allografts using second-look arthroscopy. Materials and Methods: The outcomes of 193 consecutive patients (153 males and 40 females, with an average age of 30.38 and BMI of 25.43 kg/m2) who underwent second-look arthroscopy following primary ACLR were retrospectively reviewed. Prior to participating in this study, all patients provided written informed consent. The patients were divided into two groups: those with HT autografts and those with TAT allografts. Confounding factors were matched between the two groups using propensity score matching (PSM). ACL graft status was assessed during second-look arthroscopy using a numeric scale system based on the degree of four parameters: graft tension, continuity, synovium coverage, and vascular marking. Clinical outcomes were assessed using the Lysholm and International Knee Documentation Committee (IKDC) scores. Graft status and clinical outcomes were compared between the two groups. Additionally, a subgroup analysis based on the timing of the second-look arthroscopy (12-24 months vs. >24 months after the initial ACLR) was conducted. Results: After PSM, 62 patients were included in each group. The second-look arthroscopy was conducted at 23.6 ± 6.6 months for the HT group and at 24.0 ± 7.9 months for the TAT group (p = 0.749). The continuity and tension of the ACL graft were not significantly different between the two groups (p = 0.146 and 0.075, respectively). However, the TAT group exhibited significantly inferior synovial coverage and vascular marking of the ACL graft compared with the HT group (p = 0.021 and 0.007, respectively). These findings were consistent regardless of the timing of the second-look arthroscopy. Clinical outcomes, according to the Lysholm and IKDC scores, significantly improved in both groups with no significant differences (p = 0.386 and 0.733, respectively). Conclusions: Although there were no differences in graft tension and continuity between HT autografts and TAT allografts, the biological healing of ACL grafts, in terms of synovialization and vascularization, was superior in HT autografts compared to TAT allografts.

More knee reinjuries after ACL reconstruction compared to nonsurgical treatment of the ACL. A 2-year follow-up of the NACOX prospective cohort study.

To describe knee reinjuries and surgeries within 2 years after an acute anterior cruciate ligament (ACL) injury, in patients treated with or without ACL reconstruction (ACLR). Two years follow-up of 275 patients (52% females, mean age 25.2 [SD 7.0] years) about knee reinjuries and surgeries were analysed from the prospective NACOX cohort study, aiming to describe recovery after an acute ACL injury treated according to clinical routine. Knee reinjury was defined as increase or new symptoms due to new trauma. At 2 years after injury, 169 (61%) had undergone an ACLR. Results are presented with descriptive statistics and risk ratios (RR). Thirty-two patients sustained reinjuries within 2 years; 6 in the non-ACLR group, and 26 in the ACLR group (7 before and 19 after ACLR). Twelve patients in the ACLR group sustained a graft rupture and three did an ACL revision. Patients with non-ACLR, aged 21-25 years, had a 5.9-fold higher risk for reinjury than those aged 15-20 years (RR 5.9 [1.3-26.9]; p = 0.012). Twenty-four patients had surgery in the non-ACLR group and 36 patients in the ACLR group (excluding primary ACLR), where six were before ACLR and 30 were after ACLR. Twelve percent sustained a knee reinjury and 21% underwent knee surgery within 2 years after the index ACL injury. There was a higher reinjury incidence in the ACLR group, but no difference in incidence of surgeries. Thus, ACLR did not reduce the risk of traumatic reinjuries or surgeries, which is important for treatment decision considerations. Level I.

Primary ACL repair in a selected patient cohort: A prospective single cohort study

BackgroundAnterior cruciate ligament (ACL) tears are common knee injuries, particularly in physically active individuals. While ACL reconstruction (ACL-R) is the standard treatment, it has notable limitations. Recent interest in primary ACL repair offers a potential alternative, especially for specific tear types and patient demographics. PurposeTo evaluate the outcomes of primary ACL repair in a selected patient cohort with strict inclusion and exclusion criteria, focusing on the survival of the procedure, functional outcomes, and factors influencing success rates. MethodsThis prospective single cohort study included 61 patients who underwent primary ACL repair between June 2016 and June 2022. Patients were 50 years or younger, with recent ACL injuries and no previous knee surgeries or multiligament injuries. The primary outcomes were the survival of the repair beyond two years, measured by revision rates, and functional outcomes assessed using the Lysholm knee score, Tegner activity scale, and Lachmeter stability measurements. ResultsFifty-four patients completed a minimum follow-up of three years (average 49.6 months). The overall success rate was 82.2 %, with Sherman type 1 tears showing significantly fewer failures compared to type 2 (4.3 % vs. 31.8 %). The mean Lysholm score for successful repairs was 96, and the Tegner score dropped from a pre-injury average of 6 to 5. Adolescents had the highest failure rate (50 %), while other age groups showed better outcomes. The mean side-to-side difference in stability was 1.4 mm, favoring the control side. ConclusionPrimary ACL repair is a viable option for selected patients, particularly those with Sherman type 1 tears. While age and tear type significantly affect outcomes, the procedure shows promising results with high functional scores in successful repairs. Further research with larger cohorts and extended follow-ups is necessary to validate these findings and refine patient selection criteria. Primary ACL repair offers a less invasive alternative to ACL reconstruction, with potential for comparable outcome.

Rate and Timing of Revision and Contralateral Anterior Cruciate Ligament Reconstruction Relative to Index Surgery.

After anterior cruciate ligament (ACL) reconstruction (ACLR), ipsilateral ACL graft reinjury or contralateral ACL injury has been reported. The rate and predictors of such subsequent ACL injuries have not been reported in recent years and in large patient cohorts. The current study utilized a large, national, multi-insurance, administrative database to assess subsequent ACLR and factors associated with its occurrence. Cross-sectional study; Level of evidence, 3. Using the PearlDiver M151 database, patients who underwent ACLR within the United States between 2015 and 2021 were abstracted. All included patients had ≥3 years of evaluation after initial ACLR. Patients who underwent a subsequent reconstruction (ipsilateral or contralateral) within 3 years were determined and the timing assessed. Using univariable and multivariable logistic regression, the factors associated with having a subsequent ACLR and the factors associated with returning for ipsilateral versus contralateral ACLR were examined. In total, 40,151 patients who underwent initial ACLR during the study period were identified. Of these, subsequent ACLR was performed for 1689 patients (4.2%). These included ipsilateral revision for 1018 (60.3%) and contralateral reconstruction for 671 (39.7%) patients. Patients returning for ipsilateral reconstruction did so sooner than patients needing a contralateral reconstruction. On multivariable analysis, the only factor independently associated with subsequent ACLR was younger age (odds ratio [OR] = 4.17 for 10-14 years relative to 25-29 years; P < .0001). Factors associated with returning for an ipsilateral revision ACLR as opposed to contralateral ACLR were earlier revision (OR = 1.49 within 1.5 years relative to after 1.5 years; P = .0001) and female sex (OR = 0.62 relative to male sex; P < .0001). The overall rate of requiring a subsequent ACLR was found to be 4.2%, with 60.3% of these being to the ipsilateral ACL. This information may be helpful for evolving injury-prevention programs and patient counseling.

Association of Anterior Knee Pain With Extension Deficit After Anterior Cruciate Ligament Reconstruction: A Systematic Review.

Previous systematic reviews have reported the incidence of anterior knee pain (AKP) and extension deficit (ED) after anterior cruciate ligament reconstruction (ACLR); however, both outcomes are estimated separately and thus are assumed to be uncorrelated. To estimate whether there is a clinically relevant association between the population effects of ED and AKP after ACLR. Systematic review; Level of evidence, 2. Under PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review was conducted by searching PubMed, EMBASE, and the Cochrane Library electronic databases for published articles reporting incidence of both AKP and ED after ACLR with either bone-patellar tendon-bone (BPTB) or hamstring (HS) graft that returned 298 studies after the initial search. A Bayesian hierarchical measurement error model estimated the population effect of ED and AKP. Twelve publications involving 976 patients (mean follow-up, 77.9 months; range, 24-180 months) were included in the systematic review. There was a clear, moderate correlation between population ED and population AKP for the BPTB (r = 0.40; 95% CI, 0.39-0.42) and the HS grafts (r = 0.35; 95% CI, 0.33-0.36). Model expected estimates for the population effects of AKP and ED were 24.1% (95% CI, 17.4%-31.9%) and 17.5% (95% CI, 10.6%-25.0%), respectively, for the BPTB graft and 16.1% (95% CI, 9.2%-23.9%) and 13.1% ED (95% CI, 6.0%-20.8%) for the HS graft, respectively. The posterior mean difference in AKP between BPTB and HS grafts was clear and substantial (8.3% [95% CI, 0.3% to 16.1%]); there was no substantial difference in the posterior mean difference of ED between BPTB and HS grafts (4.3% [95% CI, -3.8% to 13.0%). Our systematic review demonstrated a moderate but clear correlation between ED and AKP irrespective of graft type. From a clinical perspective, this association emphasizes the need for intraoperative achievement of full extension and avoidance of situations that may cause ED. The higher incidence of AKP in patients with BPTB graft may also be attributed to factors related to the graft harvest site. Future metaregression analyses could investigate whether additional factors such as follow-up duration or rehabilitation protocols can moderate the association between AKP and ED after ACLR with either BPTB or HS graft.

The Efficacy of Blood Flow Restriction Training to Improve Quadriceps Muscle Function after ACL Reconstruction.

Blood flow restriction training (BFRT) is a popular rehabilitation intervention after anterior cruciate ligament reconstruction (ACLR). However, there are a lack of clinical trials establishing the efficacy of using BFRT during rehabilitation to improve quadriceps muscle function. To evaluate the efficacy of blood flow restriction training to improve quadriceps muscle strength, morphology, and physiology, and knee biomechanics in individuals after ACLR in a double-blind, randomized, placebo-controlled clinical trial (NCT03364647). 48 athletes (20 females/28 males) were randomly assigned to low-load strength training with active BFRT or standard of care strength training with a sham unit. Treatment occurred for 1-month pre-surgery and 4-5 months post-surgery with both groups following the same standard rehabilitation protocol. Outcome variables were measured at baseline and 4-5 months post-surgery. Quadriceps muscle strength (isometric and isokinetic peak torque and rate of torque development) was measured on an isokinetic dynamometer. Quadriceps muscle morphology (physiological cross-sectional area, fibrosis) was determined using magnetic resonance imaging. Quadriceps muscle physiology (fiber type, fiber cross-sectional area, satellite cell abundance, collagen content, fibro-/adipo-genic progenitor cells) was evaluated with muscle biopsies of the vastus lateralis. Knee extensor moment and knee flexion angle were measured via three-dimensional gait analysis. Change scores were calculated as: post-intervention-baseline. Two sample t-tests were then used to assess between-group differences for each outcome variable. No significant between-group differences were found for any outcome variable. The addition of BFRT to a rehabilitation program for athletes pre- and post- ACLR was no more effective than standard rehabilitation for improving quadriceps muscle function. Clinicians should consider the value of BFRT relative to the cost, time, and discomfort for patients in light of these results.

Residual Performance and Biomechanical Asymmetries During Jumping Tasks in Female Athletes at 9 Months After Anterior Cruciate Ligament Reconstruction.

Biomechanics and anterior cruciate ligament injury mechanisms differ in males and females. There is a need for more data on between-limb biomechanical differences after anterior cruciate ligament reconstruction (ACLR) in females. To explore biomechanical asymmetries throughout the kinetic chain during the single-legged (SL) and double-legged (DL) countermovement jump (CMJ) and drop jump (DJ) in female athletes after ACLR. Descriptive laboratory study. Kinematic and kinetic between-limb differences were analyzed during the SL and DL CMJ and DJ in 67 female athletes 9 months after ACLR. Biomechanical and performance asymmetries between limbs during the jumps and isokinetic strength testing were analyzed with statistical parametric mapping. The entire stance phase was used for the paired t tests of the biomechanical variables, with Cohen d effect sizes of significant portions of the stance phase (reported as % of stance) calculated in a point-by-point manner. Decreased vertical ground-reaction force, internal knee abduction moment, knee internal rotation angle, hip external rotation angle, internal ankle eversion, and external rotation moments were seen in the ACLR limb during all 4 vertical jump tests. The greatest number and highest value of differences were found during the DLDJ, with asymmetries having medium to large effect sizes. They tended to appear more frequently in the concentric phase (50% to 100% of stance) during the SLCMJ and DLCMJ and in the eccentric (0% to 49% of stance) and concentric (50% to 100% of stance) phase during the SLDJ and DLDJ. For the SLCMJ, SLDJ, and quadriceps strength, performance asymmetries of >15% were detected but not for change of direction. The findings suggest that return-to-play testing in female athletes should examine the entire stance phase and include assessments of kinetic and kinematic variables throughout the kinetic chain. Greater deficits were highlighted in the DJ than in the CMJ, and greater performance asymmetries were evident in the SL tasks, with greater kinetic and kinematic and compensatory strategies evident in the DL tests. Biomechanical analysis focusing on contralateral compensation strategies and sex-specific interventions are necessary before return to play.

Comparing Sagittal-Plane Biomechanics of Drop Jump Landing in Athletes With and Without Knee Osteoarthritis 2-Year Post-Anterior Cruciate Ligament Reconstruction.

The study aimed to determine differences in sagittal-plane joint biomechanics between athletes with and without knee osteoarthritis (OA) during drop vertical jump 2years after anterior cruciate ligament reconstruction (ACLR). Forty-one athletes with ACLR completed motion analysis testing during drop vertical jump from 30cm. Sagittal-plane peak joint angles and moments and joint contributions to total support moment (TSM) were calculated during first landing. Medial compartment knee OA of the reconstructed knee was evaluated using Kellgren-Lawrencescores (ACLR group: Kellgren-Lawrence <2; ACLR-OA group: Kellgren-Lawrence ≥2). The ACLR-OA group (n = 13) had higher hip and lower knee contributions in the surgical limb than the ACLR group and their nonsurgical limb. Further, the ACLR-OA group had higher peak hip extension moment than the ACLR group (P = .024). The ACLR-OA group had significantly lower peak knee extension and ankle plantar flexion moments and TSM (P ≤ .032) than ACLR group. The ACLR-OA group landed with increased hip extension moment, decreased knee extension and ankle plantar flexion moments and TSM, and decreased knee and increased hip contributions to TSM compared with ACLR group. The ACLR-OA group may have adopted movement patterns to decrease knee load and compensated by shifting the load to the hip. Clinicians may incorporate tailored rehabilitation programs that mitigate the decreased knee load to minimize the risk of knee OA after ACLR.