One in 5 Athletes Sustain Reinjury Upon Return to High-Risk Sports After ACL Reconstruction: A Systematic Review in 1239 Athletes Younger Than 20 Years

Neurocognitive and Neuromuscular Rehabilitation Techniques after ACL Injury, Part 1: Optimizing Recovery in the Acute Post-Operative Phase- A Clinical Commentary

Anterior cruciate ligament (ACL) injury rates are on the rise, despite improved surgical techniques and prevention programs. While traditional rehabilitation emphasizes the restoration of motion, strength, and physical performance, emerging research highlights the importance of addressing neurocognitive deficits that can persist after injury. These deficits, including altered proprioception, impaired motor control and muscle recruitment, as well as heightened reliance on visual feedback, can significantly increase the risk of re-injury and impede return to sport. The purpose of this clinical commentary is to outline a proposed comprehensive approach to rehabilitation that challenges the neurocognitive system to optimize rehabilitation outcomes and reduce reinjury risk. Thus, this clinical commentary discusses the rationale for integrating neurocognitive training into all phases of ACLR rehabilitation, from initial injury to eight weeks post-surgery. It details the neurophysiological changes caused by ACL injury and presents evidence supporting the use of exercises that challenge visual attention, decision-making, and motor planning. A comprehensive rehabilitation framework incorporating both physical and neurocognitive components is proposed, aiming to improve long-term outcomes and reduce re-injury risk. Level of Evidence: 5.

How Athletic Swiss Patients Experience Their Return to Sports After Anterior Cruciate Ligament Reconstruction: Results from a Retrospective Self-Assessment

Introduction

Anterior cruciate ligament (ACL) ruptures are frequent injuries, especially in athletes. Return to sports after reconstruction of the ligament is a frequently debated topic and of high relevance for these patients. It is mostly achieved at 9-12 months post-surgery. However, the risk of subsequent knee injuries is high and psychological factors play an important role in the process and success of returning to sports. Little is known about patients' perception of their journey returning to sports. This study aims to fill the gap.

Material and Methods

The study aimed to include patients treated surgically for an ACL injury over 5 years at a specialized sports-medicine clinic. Patients were surveyed on the impact of the injury on their lives, their return to sports experience, and medical history.

Results

In total, 100 (of 474) patients aged 35.9 years responded. Within 5 years, 19% experienced a reoperation and 23% a new knee injury. Overall, 83% of patients returned to their main sport, 72% reached their pre-injury level. However, 45% reported at least one distinct or severe consequence of their ACL injury. The ability to return to sports had more impact on the perception of the course of treatment than the experience of new injuries or surgery.

Conclusion

The rate of successful return to sports was comparable to previous reports despite a higher average age in this cohort. A successful return to sports seems to be a major determinant for the perception of impact from the injury and may be more important than the avoidance of repeat trauma.

Graft Failure and Contralateral ACL Injuries After Primary ACL Reconstruction: An Analysis of Risk Factors Using Interpretable Machine Learning

Background

Anterior cruciate ligament (ACL) reconstruction (ACLR) can be successful in restoring knee stability. However, secondary ACL injury, either through graft failure or contralateral injury, is a known complication and can significantly impact the ability of a patient to return successfully to previous activities.

Purpose

To develop and internally validate an interpretable machine learning model to quantify the risk of graft failure and contralateral ACL injury in a longitudinal cohort treated with ACLR.

Study Design

Case-control study; Level of evidence, 3.

Methods

An established geographic database of >600,000 patients was used to identify patients with a diagnosis of ACL rupture between 1990 and 2016 with a minimum 2-year follow-up. Medical records were reviewed for relevant patient information and 4 candidate machine learning algorithms were evaluated for prediction of graft failure and contralateral ACL injury in patients after ACLR as identified either on magnetic resonance imaging or via arthroscopy. Performance of the algorithms was assessed through discrimination, calibration, and decision curve analysis. Model interpretability was enhanced utilizing global variable importance plots and partial dependence curves.

Results

A total of 1497 patients met inclusion criteria. Among them, 140 (9.4%) had graft failure and 128 (8.6%) had a contralateral ACL injury after index surgery at a median follow-up of 140.7 months (interquartile range, 77.2-219.2 months). The best performing models achieved an area under the receiver operating characteristics curve of 0.70 for prediction of graft failure and 0.67 for prediction of contralateral ACL injury, outperforming a logistic regression fitted on the identical feature set. Notable predictors for increased risk of graft failure included younger age at injury, body mass index (BMI) <30, return to sports <13 months, initial time to surgery >75 days, utilization of allograft, femoral/tibial fixation with suspension/expansion devices, concomitant collateral ligament injury, and active or former smoking history. Predictors of contralateral ACL injury included greater preoperative pain, younger age at initial injury, BMI <30, active smoking history, initial time to surgery >75 days, history of contralateral knee arthroscopies, and involvement in contact sports.

Conclusion

Less than 18% of all patients who undergo ACLR should be expected to sustain either a graft failure or contralateral ACL injury. Machine learning models outperformed logistic regression and identified greater preoperative pain, younger age, BMI <30, earlier return to higher activity, and time to surgical intervention >75 days as common risk factors for both graft failure as well as contralateral ACL injury after ACLR. Surgeon-modifiable risk factors for graft failure included allograft and femoral/tibial fixation with a suspension/expansion combination.

An 8-week physiotherapist-led return to sport group program after anterior cruciate ligament reconstruction improves measures of physical and psychological function: A case series

BACKGROUND

Low return to competitive sport, high reinjury rates and long-term functional impairment of anterior cruciate ligament reconstruction (ACLR) present significant challenges for patients. A program that facilitates a safe return to sport (RTS) following ACLR could potentially improve outcomes.

STUDY DESIGN

Case Series.

METHODS

Sixty participants (median 20-years-old (13-36), 43 males, 18 females, median 7.5 months (4-25) post-ACLR) completed an eight-week exercise program. A battery of physical tests and patient-reported outcome measures were assessed pre and post-program. The number of participants passing RTS criteria was evaluated, and RTS rates were determined. The correlation between the ACL-RSI and measures of physical function was explored.

RESULTS

Improvements in all isometric strength, hop tests, running T-test, and patient reported outcome measures were seen post-program. Five (8%) participants successfully passed all RTS criteria and eighty-five percent of participants returned to their previous level of sport. The ACL-RSI and the IKDC showed correlation across all time points (pre rs = 0.49; post rs = 0.40; change r = 0.40).

CONCLUSIONS

Our study demonstrated improvements in all RTS criteria tests upon completing the 8-week rehabilitation program; however, few participants (8%) passed all RTS criteria. Psychological readiness is more closely related to patient-reported function than functional tests.

Clinical Utility of Qualitative Change of Direction Movement Assessment in ACL Injury Risk Evaluation

Anterior cruciate ligament (ACL) injuries are complex and influenced by numerous internal and external risk factors that should be considered to effectively mitigate injury and facilitate informed return to sport decision-making. Among these risk factors, movement quality exhibited during sport-specific tasks has been identified as a significant predictor of injury occurrence. Particularly, change of direction (COD) movements, when performed with sub-optimal movement quality, such as knee valgus and lateral trunk flexion, are prominent mechanisms of ACL injury in multidirectional sports. Unfortunately, the formal and objective assessment of COD movement quality is underutilized in clinical and sports practice, with existing methods often confined to expensive, sophisticated laboratory settings impractical for everyday clinicians. The purpose of this clinical commentary is to demonstrate the necessity of integrating COD movement assessments to screen for potential ACL injury risk, particularly among higher-risk populations. The authors will review cost-effective and clinic-friendly objective tests used to qualitatively screen COD movements, such as the Cutting Movement Assessment Score and The Expanded Cutting Alignment Tool. Additionally, this commentary will discuss key considerations when assessing COD movement.

Level of Evidence

5.

Return to Play at Preinjury Level After Anterior Cruciate Ligament Reconstruction in Divisions II and III National Collegiate Athletic Association Student-Athletes

Background

The rates of return to play (RTP) after anterior cruciate ligament (ACL) reconstruction among professional and National Collegiate Athletic Association (NCAA) Division I athletes are well described in the orthopaedic literature. Less is known about these rates and risk factors for failure to RTP in Division II and III collegiate athletes.

Purpose

To determine the RTP rate after ACL reconstruction among Division II and III collegiate athletes and to explore the factors associated with RTP.

Study Design

Case series; Level of evidence, 4.

Methods

Demographic and RTP data were retrospectively reviewed for collegiate athletes who underwent ACL reconstructions across high-risk sports over 6 years (2015/16 to 2021/22 seasons) at 5 northeastern NCAA Division II and III institutions. Clinical data collected included Patient Acceptable Symptom State (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation questionnaire, graft type, concomitant reparative surgery, reinjury, need for reoperation, and time to RTP and return to preinjury level. Participants completed the survey using a secure web-based questionnaire sent via email or over the telephone at a minimum 6-month follow-up. Descriptive frequencies were calculated for all documented variables, with chi-square and analysis of variance statistics used to assess for associations and significant differences between variables.

Results

A total of 61 eligible student-athletes with primary ACL reconstructions were identified in this study period, and 40 knees were enrolled for analysis with a mean time from surgery to survey completion of 45.0 months. The overall RTP rate was 77.5% (31/40) at a mean of 10.1 months. However, only 50.0% (20/40) returned to their preinjury level of competitive play. There was a graft failure rate of 20% (8/40). Of the 32 athletes who did not reinjure their ACL, 81.25% (26/32) demonstrated a PASS on KOOS Sports and Recreation. Graft rerupture (P < .001) and reoperation (P = .007) had significant effects on rates of RTP. Concomitant procedures (P = .010) influenced return to preinjury level of sports. Injury during the active season versus the off-season significantly influenced KOOS PASS status (P = .038).

Conclusion

This study demonstrated that the rate of RTP after ACL reconstruction in this patient population of Division II and III collegiate athletes was 77.5%, with only 50% returning to their preinjury level of competitive play. The graft failure rate in this population was 20%. Surgical factors, such as concomitant surgeries and reinjury of ACL graft, as well as athlete-specific data, such as injury in the off-season, were statistically significant negative influences on patient outcomes. Further research is needed to evaluate other potential factors that may play a role in RTP after ACL reconstruction.

Less Subsequent Revision Anterior Cruciate Ligament Reconstruction Following Primary Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction with Suture Tape Augmentation-A Retrospective Comparative Therapeutic Trial With 5-Year Follow-Up

PURPOSE

To investigate patient outcomes, including revision rate, following primary bone patellar-tendon bone autograft (BPTB) anterior cruciate ligament reconstruction (ACLR) with and without suture tape augmentation (STA) in a young and active cohort.

METHODS

All eligible patients who received primary BPTB ACLR with a minimum of 2-year follow-up were included in this retrospective cohort study. All patients receiving STA were augmented with the same device. Patients completed the following patient-reported outcome measures (PROMs): the visual analog scale, the Single Assessment Numeric Evaluation, the Knee Injury and Osteoarthritis Outcome Score subscales, and the Tegner activity scale. Anteroposterior knee laxity was assessed using a KT-1000 arthrometer preoperatively and 1-year postoperatively. Posterior tibial slope, femoral tunnel angle, and tibial tunnel placement were calculated for all patients. Subsequent surgical interventions and return to sport (RTS) were obtained from each patient.

RESULTS

One hundred fourteen patients (52 BPTB ACLR with STA, 62 traditional BPTB ACLR) with a mean patient age <19 years and a mean final follow-up of ≥5 years were included. Compared with the control group, the STA group demonstrated significantly less subsequent revision ACLR (0 vs. 5, P = .036). All PROMs and KT-1000 measurements improved at final follow-up (P < .001) and were comparable between groups. There were no differences seen in either posterior tibial slope or graft tunnel placement between groups. More than 85% of the patients were able to return to the sport that led to their injury at full capacity with no differences seen in RTS rate, time to RTS, or level of competition between groups.

CONCLUSIONS

Compared with traditional BPTB ACLR, additional STA appeared to safely and effectively lead to less subsequent revision ACLR while maintaining acceptable PROMs and objective joint laxity measurements in a young and active patient population.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Assessing the Impact of Psychological Readiness on Performance and Symmetry in Functional Testing After ACL Reconstruction in Pediatric and Adolescent Patients

Background

Readiness for return to sports involves both physical and psychological aspects of recovery; however, the relationship between psychological and physical variables after anterior cruciate ligament (ACL) reconstruction (ACLR) is poorly understood.

Hypothesis

ACLR patients with a higher psychological readiness would demonstrate better functional testing results at 6 months.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Participants were evaluated at 6 months after ACLR with various patient-reported outcome metrics: Hospital for Special Surgery Pediatric Functional Activity Brief Scale, pediatric or adult International Knee Documentation Committee Questionnaire (IKDC), Patient-Reported Outcomes Measurement Information System (PROMIS) - Psychological Stress Experience and ACL - Return to Sport After Injury (ACL-RSI) scale. Functional testing included quadriceps, hamstrings, and gluteal strength testing; Y-balance test; single-leg single hop, crossover hop, and triple hop tests; and timed 6-m hop test. Pearson correlation coefficient and multivariable regression were used to determine associations between the limb symmetry index (LSI) on functional testing and patient-reported outcomes. Those with LSI deficits <20% (better performance) were compared with those with deficits >20% (worse performance).

Results

A total of 229 participants (89 male, 140 female) with a median age of 17 years (range, 10.3-30.6 years) were enrolled. IKDC had a moderate negative correlation with PROMIS - Psychological Stress Experience (r = -0.39; 95% CI = -0.49, -0.27; P < .001) and a moderate positive correlation with ACL-RSI (r = 0.55; 95% CI = 0.46, 0.64; P < .001). A total of 151 patients completed functional testing. ACL-RSI demonstrated a positive correlation with single-hop LSI (r = 0.21; 95% CI = 0.05, 0.35; P = .01) and timed 6-m hop (r = 0.28; 95% CI, 0.42; P = .001). When adjusting for sex, age, and graft type, patients who had <20% deficit on the single-hop test scored 16.6 points higher on ACL-RSI (P = .001), and those with <20% deficit on crossover hop testing scored a mean 13.9 points higher on ACL-RSI (P = .04).

Conclusion

Higher psychological readiness for return to sport was associated with better performance and greater symmetry on hop testing 6 months after ACLR, suggesting a potential link between physical and psychological recovery.

Effectiveness of psychological intervention following anterior cruciate ligament reconstruction: A systematic review and meta-analysis

OBJECTIVE

To determine the effectiveness of psychological interventions in postoperative anterior cruciate ligament reconstruction (ACLR) compared to standard rehabilitation.

METHODS

The databases searched were PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, PEDro, Cumulative Index to Nursing & Allied Health Literature, and EMBASE were searched from each database inception to May 2023 for published studies. The methodological quality was assessed with the Cochrane Risk of Bias Assessment (RoB 2.0) tool. The evidence quality was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

Six papers were included in the meta-analysis. Psychological intervention significantly improved Tampa Scale for Kinesiophobia at 3 months (Standard Mean Difference [SMD], -0.51. 95% Confidence Interval [CI], -0.85 to -0.17) and pain (Knee Injury and Osteoarthritis Outcome Score for Pain, Numeric Rating Scale, Visual Analog Scale) at 3 months (SMD, -0.92. 95%CI, -1.69 to -0.15) and at 6 months following ACLR (MD, -1.25. 95%CI, -1.82 to -0.68) when compared with the standard rehabilitation, according to very low-quality data. Self-efficacy and knee strength did not show significant differences.

CONCLUSION

Very low-quality evidence suggests that psychological intervention following ACLR yields better short-term outcomes compared to standard rehabilitation, with uncertainty about its clinically significant benefits over standard rehabilitation.

Transphyseal arthroscopic anterior cruciate ligament reconstruction in children under 12 years

BACKGROUND

The incidence of anterior cruciate ligament (ACL) injuries in children is on the rise. Despite this trend, the optimal management of these injuries remains a matter of ongoing debate. In this light, our study seeks to assess the clinical, radiological, and functional outcomes of transphyseal ACL reconstruction in preadolescent patients in the medium-term.

METHODS

This prospective study included preadolescent patients aged up to 12 years who underwent ACL transphyseal reconstruction between 2010 and 2020 and had a minimum follow-up of 2 years. Clinical assessments encompassed joint stability and range of motion. Furthermore, leg length discrepancy (LLD) and femorotibial alignment were evaluated both clinically and radiologically using full-length lower limb standing radiographs. Pre- and postoperative functional outcomes were assessed using the International Knee Documentation Committee (IKDC) and Lysholm scales, and the return to normal sports activity was evaluated using the ACL-Return to Sport after Injury (ACL-RSI) scale. Complications and relevant follow-up data were also recorded. Statistical analyses were conducted to evaluate these outcomes.

RESULTS

A total of 35 preadolescent patients, consisting of 24 males and 11 females, with a mean age at surgery of 11.2 ± 0.7 years (8.7-12), were included in the study. The mean follow-up was 52.3 ± 20.7 months (24.1-95.9). No significant growth disturbances or clinically relevant LLD were evidenced. All patients demonstrated clinically stable knees with full range of motion at the 2-year follow-up. There were statistically significant improvements in pre- and postoperative IKDC (39.3 ± 13.5 vs. 99.7 ± 0.8, p < 0.005) and Lysholm scores (48.2 ± 15.1 vs. 99.6 ± 1.4, p < 0.005). All but two patients were able to return to their pre-injury level of sports activity, with a mean ACL-RSI score of 93.5 ± 1.3. The analysis revealed an 8.6% rerupture rate and an 11.4% rate of contralateral ACL injuries, with 5-year survival rates of 92.3% and 88.8%, respectively. Subgroup analyses based on age, gender, surgical delay, or associated meniscal lesions did not reveal any significant differences in functional outcomes. Additionally, there was no discernible relationship between age or timing of ACL reconstruction and the risk of meniscal injuries.

CONCLUSIONS

Our study reinforces the value of ACL reconstruction in skeletally immature preadolescent patients, with transphyseal technique proven to be a safe, effective, and technically simpler option, even for children under the age of 12. The findings indicate excellent functional outcomes, a high rate of successful return to sporting activities, and minimal to no incidence of growth-related complications in the medium-term.

LEVEL OF EVIDENCE

Level II, prospective comparative cohort study, before and after intervention.

Infratubercle Anterior Closing Wedge Osteotomy Corrects Sagittal Alignment without Affecting Coronal Alignment or Patellar Height

Background: Excessive posterior tibial slope (PTS) has been associated with a higher risk of graft failure after anterior cruciate ligament reconstruction (ACLR). Although anterior closing wedge osteotomy (ACWO) can reduce the PTS, it may also change the coronal alignment and patellar height. Purpose: To elucidate the radiological outcomes after infratubercle ACWO, specifically to evaluate its influence on perioperative changes in patellar height. Methods: Patients who underwent infratubercle ACWO with combined ACLR with a minimum follow-up of 3 months were included. Surgery was indicated when the PTS was greater than 12°. Radiological evaluation included measurements of the hip-knee-ankle angle (HKA), PTS, femoral patellar height index (FPHI), and Caton-Deschamps index (CDI) preoperatively and 3 months postoperatively. Patellar height was classified as patella baja, normal, or alta based on CDI values. Knee recurvatum was measured preoperatively and at final follow-up. Results: A total of 21 patients with a mean age of 21.6 ± 3.0 years were included. Although HKA did not significantly change, significant corrections were achieved in the PTS from 14.5° ± 1.6° to 5.7° ± 1.0° (p < 0.001). No significant change in FPHI was found (preoperative: 1.33 ± 0.11 vs postoperative: 1.30 ± 0.09). Patellar height categories showed no significant differences pre- and postoperatively, while three patients (14.3%) changed their patellar height category (all moved up one category). Knee recurvatum increased significantly from 4.9° ± 2.9° preoperatively to 7.8° ± 3.1° at the final follow-up (p < 0.001). Conclusions: Precise sagittal correction was achieved after infratubercle ACWO without altering the coronal alignment and patella height. Level of Evidence: IV, Case series.

Observe, Practice, and Improve? Enhancing Sidestep Cutting Execution in Talented Female Soccer Players: A Four-Week Intervention Program With Video Instruction

ABSTRACT

Nijmeijer, EM, Kempe, M, Elferink-Gemser, MT, and Benjaminse A. Observe, practice and improve? Enhancing sidestep cutting (SSC) execution in talented female soccer players: A four-week intervention program with video instruction. J Strength Cond Res 38(8): e430-e439, 2024-Implicit learning has the potential to improve movement execution and reduce injury risk. Previous research showed beneficial effects of short-term interventions with implicit learning in male athletes. However, research on long-term interventions in female athletes is lacking. The aim of this study was to examine the effects of a 4-week intervention with video instruction on movement execution of SSC, a task that is highly related with anterior cruciate ligament (ACL) injury risk, in female athletes. Twenty talented adolescent female soccer players were part of the control (CTRL, n = 10) or video instruction (VIDEO, n = 10) group. All subjects practiced 4 weeks and received general task instructions. In addition, the VIDEO group received expert video instruction during practice. Lower extremity kinematics and kinetics and vertical ground reaction force of SSC were examined during baseline, immediate post, and 1-week retention tests. After nonlinear registration, differences between each subject and the expert she had seen were determined. These differences were analyzed with SPM1D 2-way ANOVA. No interaction effects between time and group were found ( p > 0.05). Main effects of time were found in the frontal plane. In particular, smaller deviations of subjects compared with the seen expert of the knee adduction ( p = 0.005, 97.9-100% stance phase [SP]) and hip abduction ( p = 0.005, 11.5-13.8% SP) and adduction ( p < 0.001, 33.4-87.7% SP) moments were found in immediate post compared with baseline. These frontal plane short-term improvements, replicating earlier findings in both sexes, may lower ACL injury risk. The large observed interindividual differences over time may have concealed the long-term effects of video instruction at the group level.

Risk Factors of Emergency Department Utilization After Outpatient Surgery for Sports-Related Injuries

INTRODUCTION

The purpose of this study was to identify the most common reasons for and risk factors associated with postoperative emergency department (ED) utilization after orthopaedic procedures for sports-related injuries.

METHODS

Using the 2014 to 2016 New York and Florida State Databases from the Healthcare Cost and Utilization Project, outpatient procedures for sports-related injuries were identified. Patient records were tracked across care settings within each state to determine the rate and reasons of postoperative ED utilization within 90 days after the index surgery. Multiple logistic regression models were used to identify risk factors associated with ED visits at 0 to 7 days, 8 to 30 days, 31 to 90 days postoperatively.

RESULTS

A total of 28,192 surgery visits for sports-related injuries were identified, with knee arthroscopy with partial meniscectomy (18.48%) and arthroscopic anterior cruciate ligament reconstruction (17.04%) as the two most common procedures treating sports injuries. The overall postoperative ED utilization rates were 1.6% (0 to 7 days postoperative), 1.3% (8 to 30 days) and 2.1% (31 to 90 days). The main cause of ED visits was markedly different during each postoperative period: mainly musculoskeletal pain (36.3%) during 0 to 7 days, either musculoskeletal pain (17%) or injury (16.6%) during 8 to 30 days, and injury (24.2%) during 31 to 90 days. Sports with the highest ED utilization in descending order were basketball, football, ice/snow sports, walking/running, cycling, and soccer. Relative to open procedures, arthroscopic procedures were 0.71 times as likely to result in a postoperative ED visit. Independent predictors of ED utilization up to 90 days postoperatively included renal failure, chronic pulmonary disease, psychosis, diabetes, and alcohol abuse.

DISCUSSION

Rate of ED utilization after outpatient surgery for sports-related injuries is low (<2.2%), with postoperative musculoskeletal pain and reinjury as the two most common causes, highlighting the importance of postoperative pain management and injury prevention. Arthroscopic procedures showed markedly lower ED utilization compared with open surgery, although not indicative of overall superiority.

LEVEL OF EVIDENCE

III, Retrospective Cohort Study.

Combined ACLR and lateral extra-articular tenodesis with a continuous iliotibial band autograft is a viable option in a population of athletes who participate in pivoting sports

PURPOSE

The aim of this study was to evaluate the clinical results, return to sport and complications after anterior cruciate ligament reconstruction (ACLR) associated with lateral extra-articular tenodesis using continuous plasty with an iliotibial band.

METHODS

This was a prospective multicentre study involving 186 patients who had surgery for anterior cruciate ligament (ACL) rupture. Patients with multiligament ruptures and revision surgery were excluded from the study. All patients included were involved in pivoting sports and wished to resume their activity after surgery. Patients were assessed at a minimum 2-year follow-up using functional and psychological questionnaires (subjective International Knee Documentation Committee [IKDC], Tegner, Lysholm and ACL-RSI scores), ligament assessment including instrumented laxity measurement (Rolimeter), Lachman test and pivot shift and isokinetic testing. Return to sport was assessed using a questionnaire, and complications and repeat surgeries were recorded.

RESULTS

At a mean follow-up of 43.1 months, the subjective IKDC, Lysholm, ACL-RSI and objective IKDC scores were significantly improved (59.8 vs. 94.5 p < 0.0001, 75 vs. 99 p < 0.0001, 60 vs. 93 p < 0.0001, IKDC A 0% vs. 72%, B 12% vs. 27%, C 60% vs. 1% D 28% vs. 0% p < 0.0001). The Tegner activity level was 9 (3-10) before the accident and 9 (3-10) at the last review. Seventy-six percent of the patients had returned to sports at the same level. The differential laxity was 6.6 mm (±1.7) preoperatively and 1.1 mm (±1.4) postoperatively. Additionally, 97% were equal in pivot shift at the last follow-up. At the 6-month isokinetic assessment, the muscle strength recovery for the quadriceps and hamstring was over 85% compared with the healthy side for 79% and 70% of the patients, respectively. Ten patients had graft rupture (5.6%). Four (2.4%) patients had a contralateral ACL rupture, and seven (4%) underwent a reoperation with meniscectomy.

CONCLUSION

Anterior ligament reconstruction with lateral extra-articular tenodesis using a continuous strip of iliotibial band enables 76% of patients in a population with a high demand for sports to resume their activities at the same level. The clinical results and complication rates, particularly reruptures (5.6%), were similar to those of other techniques involving lateral extra-articular tenodesis.

LEVEL OF EVIDENCE

Level II.

Previous Knee Surgery, Anteromedial Portal Drilling, Quadriceps Tendon Autograft, and Meniscal Involvement Associated With Delayed Return to Sport After Anterior Cruciate Ligament Reconstruction in Amateur Athletes

Purpose

To identify prognostic factors associated with a delayed return-to-sport (RTS) time in amateur athletes who return to full participation after a primary isolated anterior cruciate ligament (ACL) reconstruction.

Methods

A retrospective review was performed among athletes who underwent ACL reconstruction between October 2014 and October 2021. Inclusion criteria were any amateur athletes with an ACL reconstruction who had a documented RTS and greater than 1-year follow-up. Nonathletes, those with multiligamentous knee injury, and those missing documented RTS timelines were excluded. RTS was defined as participation in athletics at a level equivalent to or greater than the preinjury level participation. Demographic and prognostic factors, including previous knee surgery, meniscal involvement, level of participation, surgical approach, and graft type, were recorded along with RTS time and analyzed via Poisson regression.

Results

In total, 91 athletes, average age 18.8 (± 6.7) years, who underwent ACL reconstruction at a single institution from 2014 to 2021 were identified with an average follow-up time of 4.6 (± 2.5) years (range 1.1, 9.0). Meniscal involvement (1.11; 95% confidence interval [CI] 1.08-1.15, P < .001) and previous knee surgery (1.43; 95% CI 1.29-1.58; P < .001) were related to a delayed RTS. Quadriceps tendon and bone-patellar tendon-bone autografts, as well as allograft, showed a significant association with a longer RTS time when compared with hamstring autograft (1.16, 95% CI 1.13-1.20, P < .001; 1.04, 95% CI 1.01-1.07, P = .020; 1.11, 95% CI 1.03-1.19, P = .004, respectively), as did anteromedial portal drilling, when compared with the outside in approach for femoral drilling (1.19, 95% CI 1.16-1.23, P < .001).

Conclusions

Previous knee surgery, anteromedial femoral drilling, quadriceps tendon autograft, and meniscus tear were most associated with a delayed timeline for RTS among young athletes who were able to return.

Level of Evidence

Level IV, prognostic case series.

Independent data collectors decrease bias in the measurement of adherence to anterior cruciate ligament injury prevention programs

OBJECTIVES

Studies on adherence to neuromuscular training (NMT) for anterior cruciate ligament (ACL) injury prevention are frequently biased due to the use of self-reporting by coaches or the athletes themselves. Few NMT studies use data collectors (aside from the athletes or the individuals administering the NMT program) to decrease bias when assessing the adherence of coaches and sports teams. We hypothesized that the use of a data collector who is independent of the team to evaluate adherence to NMT programs would be reliable.

METHODS

In a prior a cluster-randomized controlled trial evaluating adherence to NMT training trial, twelve boys' and nine girls' high school athletic teams in a variety of sports were enrolled. Eight data collectors (unaffiliated with the NMT program) were hired specifically to record adherence of the athletes to the NMT exercises at each team's warm-ups 2-3 times a week, prior to practices and games. In addition to the data collectors, a control group of independent observers made visits throughout the season to also record adherence (solely for the purpose of this study, alongside the data collectors and in the same fashion) in order to evaluate the data collectors' performance and determine inter-observer reliability. The inter-observer reliability between data collectors and independent observers was measured using the Kappa statistic.

RESULTS

A total of 399 warm-ups for practices or games were observed by data collectors to obtain adherence data. Independent observers also measured adherence at 58 practices or games for inter-observer reliability. Exercise instruction and alignment cues for 29 different exercises were analysed. The Kappa values ranged from 0.63 to 1.0, indicating substantial to perfect agreement. The overall Kappa values of 0.89 and 0.90 for exercise instruction and alignment cues, respectively, indicated almost perfect agreement.

CONCLUSION

The use of a data collector who is independent of the team to evaluate adherence to NMT programs (rather than athlete or coach self-reporting), was shown to be a reliable method for measurement of adherence in studies of NMT for injury prevention. Avoiding self-reporting in adherence research to NMT training may decrease bias.

LEVEL OF EVIDENCE

I.

Return to play and athletic performance in division I female volleyball players following anterior cruciate ligament injury

OBJECTIVES

The purpose of this study is to examine NCAA Division I volleyball players' return to play rates and performance statistics compared to pre-injury levels following ACL injury.

METHODS

Female volleyball players that sustained ACL injuries from 2008 to 2020 and competed in one of seven collegiate conferences (n = 99) were identified via an internet search algorithm. Players were categorized by position, academic year, and playing time pre- and post-injury. Post-injury performance statistics were gathered for a subset of outside hitters and middle blockers that played in ≥35 sets in a single season for up to 3 years following injury (mean 1.7 seasons). A control group (n = 512) was generated for demographic and statistical comparison. Mean pre-injury and post-injury statistics were compared for players that did not change positions and played ≥35 sets before and after injury.

RESULTS

Volleyball attackers were 54.7% of the control population but sustained 78.8% of identified injuries. Following ACL injury, 6.1% of players registered no in-game statistics, 16.2% played in <35 sets, 65.7% played in ≥35 sets, and 12.1% graduated. Mean performance statistics increased linearly the more years players were from ACL injury.

CONCLUSIONS

Female collegiate volleyball players return to play following ACL injury at high rates (93.1%) and maintain pre-injury performance levels. Volleyball attackers sustain ACL injuries more commonly than setters and libero/defensive specialists.

Predictive Refined Computational Modeling of ACL Tear Injury Patterns

Anterior cruciate ligament (ACL) ruptures are prevalent knee injuries, with approximately 200,000 ruptures annually, and treatment costs exceed USD two billion in the United States alone. Typically, the initial detection of ACL tears and anterior tibial laxity (ATL) involves manual assessments like the Lachman test, which examines anterior knee laxity. Partial ACL tears can go unnoticed if they minimally affect knee laxity; however, they will progress to a complete ACL tear requiring surgical treatment. In this study, a computational finite element model (FEM) of the knee joint was generated to investigate the effect of partial ACL tears under the Lachman test (GNRB® testing system) boundary conditions. The ACL was modeled as a hyperelastic composite structure with a refined representation of collagen bundles. Five different tear types (I-V), classified by location and size, were modeled to predict the relationship between tear size, location, and anterior tibial translation (ATT). The results demonstrated different levels of ATT that could not be manually detected. Type I tears demonstrated an almost linear increase in ATT, with the growth in tear size ranging from 3.7 mm to 4.2 mm, from 25% to 85%, respectively. Type II partial tears showed a less linear incline in ATT (3.85, 4.1, and 4.75 mm for 25%, 55%, and 85% partial tears, respectively). Types III, IV, and V maintained a nonlinear trend, with ATTs of 3.85 mm, 4.2 mm, and 4.95 mm for Type III, 3.85 mm, 4.25 mm, and 5.1 mm for Type IV, and 3.6 mm, 4.25 mm, and 5.3 mm for Type V, for 25%, 55%, and 85% partial tears, respectively. Therefore, for small tears (25%), knee stability was most affected when the tears were located around the center of the ligament. For moderate tears (55%), the effect on knee stability was the greatest for tears at the proximal half of the ACL. However, severe tears (85%) demonstrated considerable growth in knee instability from the distal to the proximal ends of the tissue, with a substantial increase in knee instability around the insertion sites. The proposed model can enhance the characterization of partial ACL tears, leading to more accurate preliminary diagnoses. It can aid in developing new techniques for repairing partially torn ACLs, potentially preventing more severe injuries.

Team Approach: Neuromuscular Training for Primary and Secondary Prevention of Anterior Cruciate Ligament Injury

Neuromuscular training is a method of performance optimization-typically combining plyometrics, balancing training, agility, and dynamic stabilization-predicated on improving the efficiency of fundamental movement patterns. Neuromuscular training has consistently been shown to reduce the risk of anterior cruciate ligament injury, particularly for athletes engaged in activities associated with noncontact knee injuries (i.e., women's soccer). Successful implementation of neuromuscular training programs requires input from coaches, physical therapists, athletic trainers, and physicians to generate efficacious programs with high rates of adherence.

Establishing Normal Variances and Expectations for Quadriceps Limb Symmetry Index Benchmarks Based on Time from Surgery After Anterior Cruciate Ligament Reconstruction

The anticipated timeline for muscle strength as well as return to running and sports are some of the most common inquiries by patients undergoing anterior cruciate ligament reconstruction. Despite the popularity of this procedure, the answers to these inquiries are not well described in the literature. The purpose of this study was to evaluate the range of quadriceps strength percentage and function benchmarks at various points after anterior cruciate ligament reconstruction surgery based on sex, age, and graft.

Design

Observational Cohort Study.

Methods

Patients who underwent anterior cruciate ligament reconstruction (ACLR) were evaluated at various points after their surgery with handheld dynamometer assessments. Additional hop and balance testing was performed and patients were evaluated for clearance for running and sport via a physical therapist directed functional movement assessment (FMA). The progression of quadriceps symmetry throughout the postoperative period was examined with multi-level models, estimates of time to reach 70%, 80%, and 90% quadriceps symmetry were obtained from the fitted model.

Results

A total of 164 patients were evaluated. Patients either received bone-tendon-bone (BTB) autograft (n=118) or BTB allograft (n=46) for their ACL graft. Average age was 31.1 years-of-age (SD: 13.6). Males undergoing ACLR using BTB autograft (n=53) were able to achieve 80% quadriceps symmetry earlier than females (n=65) (5.7 months vs 7.1 months), were cleared to return to run sooner (5.6 months vs 6.8 months) and passed an FMA exam earlier (8.5 months vs 10 months). Males undergoing ACLR with allograft (n=13) were able to achieve 80% quadriceps symmetry earlier than females (n=33) (3.9 months vs 5.4 months) and were cleared to run sooner (4.5 months vs 5.8 months).

Conclusion

Patients undergoing BTB autograft obtain 80% quadriceps symmetry at an average of 5.7 months for males and 7.1 months for females. Individuals under the age of 25 obtain their quadriceps symmetry faster and are cleared to return to running faster than individuals over 25. Male sex is associated with decreased amount of time to obtain clearance for running and for full activity. Male sex is associated with decreased amount of time to regain quadriceps symmetry however this was not significant.

Level of Evidence

4 (Case series).

Quadriceps and Hamstrings Activation Peaks Earlier as Athletes Repeatedly Hop, but There are Differences Depending on ACL Reconstruction Technique

Background

After Anterior Cruciate Ligament Reconstruction (ACLR) athletes face the challenge of regaining their previous competitive level while avoiding re-injury and early knee joint cartilage degeneration. Quadriceps and hamstrings strength reductions and neuromuscular alterations potentially related to risk of re-injury are present after ACLR and relate to deficits in muscle activation.

Design

Cross-sectional laboratory study.

Purpose

To examine quadriceps and hamstrings muscle activation during repeated hops in healthy pivoting-sport athletes and those who had undergone ACLR (bone-tendon-bone and semitendinosus graft) who had met functional criteria allowing return to training.

Methods

Surface electromyography (SEMG) was recorded from vastus medialis and lateralis and medial and lateral hamstrings bilaterally during 30 seconds' repeated hopping in male athletes on average eight months after ACLR surgery (5-12 months). All patients underwent hamstring (HS) (n=24) or bone-tendon-bone (BTB) reconstruction (n=20) and were compared to healthy controls (n=31). The SEMG signals were normalized to those obtained during maximal voluntary isometric contraction.

Results

A significant time shift in peak muscle activation (earlier) was seen for: vastus medialis and vastus lateralis activation in the control group, in the BTB group's healthy (but not injured) leg and both legs of the HS group. A significant time shift in peak muscle activation was seen for lateral hamstrings (earlier) in all but the BTB group's injured leg and the medial hamstrings in the control group only. Lower peak activation levels of the vastus lateralis (p\<0.001) and vastus medialis (p\<0.001) were observed in the injured compared to healthy legs and lower peak lateral hamstrings activity (p\<0.009) in the injured leg compared to control leg. Decline in medial hamstring peak activation (p\<0.022) was observed between 1st and 3rd phase of the hop cycle in all groups.

Conclusion

Repeated hop testing revealed quadriceps and hamstring activation differences within ACLR athletes, and compared to healthy controls, that would be missed with single hop tests.

Level of evidence

3.

Effects of Kinesio taping on lower limb biomechanical characteristics during the cutting maneuver in athletes after anterior cruciate ligament reconstruction

PURPOSE

To determine the effects of Kinesio taping (KT) on the biomechanical characteristics of the lower limbs during the 90° cutting maneuver in anterior cruciate ligament (ACL) reconstruction (ACLR) athletes.

METHOD

Eighteen ACLR athletes were recruited and subjected randomly to three taping conditions, KT, placebo taping (PT), and no taping (NT), followed by a 90° cutting test. A nine-camera infrared high-speed motion capture system (Vicon, T40, 200 Hz) was used to record the kinematic parameters of the lower limbs during the cutting maneuver, and a three-dimensional dynamometer (Kistler, 1000 Hz) was used to record the kinetic parameters of the lower limbs. A one-way repeated measures analysis of variance was conducted to compare the differences in the lower limb kinematic and kinetic characteristics of ACLR athletes subjected to these interventions.

RESULTS

During the landing phase, the knee valgus angle reduced significantly with KT than with NT (95% confidence interval = -1.399 to -0.154; P = 0.025), whereas no significant difference was observed between PT and NT (95% confidence interval = -1.251 to 0.217; P = 0.236). No significant differences were observed in the other kinematic variables among the three taping conditions (P > 0.05). During the landing phase, no significant differences in the kinetic variables were observed among the three taping conditions (P > 0.05).

CONCLUSIONS

Although KT does not improve the kinetic variables of athletes after ACLR during the 90° cutting maneuver, it reduces the knee valgus angle, which could reduce the risk of secondary ACL injury.

Evaluation of hop test movement quality to enhance return to sport testing. A cross-sectional study

Introduction

Return to Sport tests with functional hop tests are often used to decide when a person is ready to return to sport after an anterior cruciate ligament (ACL) injury. Poor movement quality, such as knee valgus, hip adduction and hip internal rotation is considered a risk factor for ACL injury. However, it is unclear whether existing tests adequately cover the aspect of movement quality. This study aims to investigate whether there is a relationship between the calculated limb symmetry index (LSI) of hop tests as an indication of performance and the total score of the "Quality First" assessment (movement quality). The second aim is to examine the reliability of the newly developed "Quality First" assessment for evaluating movement quality in hop tests.

Methods

The cross-sectional study recruited 34 patients with an ACL reconstruction. The vertical hop, single-leg hop for distance, and side hop tests were performed and recorded. The video recordings were assessed using the "Quality First" assessment. The Spearman correlation coefficient was calculated using the LSI and the "Quality First" total score. Intraclass correlation coefficients (ICC) and standard error of measurements (SEM) were used to calculate intra- and interrater reliability. In addition, the minimal detectable change (MDC) was determined.

Results

The correlation test between the LSI and the "Quality First" total score showed no correlation for all three jumps (r = -0.1-0.02/p-value = 0.65-0.93). The interrater reliability of the "Quality First" assessment showed fair to good reliability (ICC2: 0.45-0.60), with SEM ranging from 1.46 to 1.73 and the MDC from 4.06 to 4.8. Intrarater reliability was good to excellent (ICC3: 0.73-0.85), with SEM values ranging from 0.89 to 1.09 and the MDC from 2.47 to 3.01.

Conclusion

The quality of movement, measured with the "Quality First" assessment, indicated no correlation with the calculated LSI from jump performance, therefore movement quality should also be examined in Return to Sport tests. The "Quality First" assessment shows fair to good reliability when used by different raters. When used multiple times by the same rater, the assessment has good to excellent reliability.

Psychological Readiness to Return to Sport (RTS) and RTS Rates Are Similar in Patients After Either Bilateral or Unilateral Anterior Cruciate Ligament Reconstruction

Purpose

To compare psychological readiness to return to sport (RTS), RTS rate, level of return, and time to return between patients who underwent bilateral anterior cruciate ligament reconstruction (ACLR) and those who underwent unilateral ACLR.

Methods

The electronic medical record at a single academic medical center was queried for patients who underwent ACLR from January 2012 to May 2020. The inclusion criteria were skeletally mature patients who underwent either single or sequential bilateral ACLR and who had undergone either the primary ACLR or second contralateral ACLR at least 2 years earlier. Bilateral ACLRs were matched 1:3 to unilateral reconstructions based on age, sex, and body mass index. Psychological readiness to RTS was assessed using the validated ACL Return to Sport After Injury (ACL-RSI) scale. This, along with time to return and level of RTS, was compared between the 2 cohorts.

Results

In total, 170 patients were included, of whom 44 underwent bilateral ACLR and 132 underwent unilateral ACLR. At the time of the first surgical procedure, patients in the unilateral cohort were aged 28.8 ± 9.4 years and those in the bilateral cohort were aged 25.7 ± 9.8 years (P = .06). The average time difference between the first and second surgical procedures was 28.4 ± 22.3 months. There was no difference in psychological readiness to RTS (50.5 in bilateral cohort vs 48.1 in unilateral cohort, P = .66), RTS rate (78.0% in unilateral cohort vs 65.9% in bilateral cohort, P = .16), percentage of return to preinjury sport level (61.2% in unilateral cohort vs 69.0% in bilateral cohort, P = .21), or time to return (41.2 ± 29.3 weeks in unilateral cohort vs 35.2 ± 23.7 weeks in bilateral cohort, P = .31) between the 2 cohorts.

Conclusions

Compared with patients who undergo unilateral ACLR, patients who undergo bilateral ACLR are equally as psychologically ready to RTS, showing equal rates of RTS, time to return, and level of return.

Level of Evidence

Level III, retrospective cohort study.

The Iliotibial Band is the Main Secondary Stabilizer for Anterolateral Rotatory Instability and both a Lemaire Tenodesis and Anterolateral Ligament Reconstruction Can Restore Native Knee Kinematics in the Anterior Cruciate Ligament Reconstructed Knee: A Systematic Review of Biomechanical Cadaveric Studies

PURPOSE

To obtain a comprehensive overview of comparative biomechanical cadaveric studies investigating the effect of both the iliotibial band (ITB) and anterolateral ligament (ALL) on anterolateral rotatory instability (ALRI) in anterior cruciate ligament (ACL)-injured knees, and the effect of lateral extra-articular tenodesis (LET) versus ALL reconstruction (ALLR) in ACL-reconstructed knees.

METHODS

An electronic search was performed in the Embase and MEDLINE databases for the period between January 1, 2010, and October 1, 2022. All sectioning studies comparing the role of both the ITB and ALL on ALRI and all studies comparing the effect of both LET and ALLR were included. Articles were assessed for methodological quality according to the Quality Appraisal for Cadaveric Studies scale.

RESULTS

Data of 15 studies were included, representing the mean values of biomechanical data collected from 203 cadaveric specimens, with sample sizes ranging from 10 to 20 specimens. All 6 sectioning studies reported that the ITB acts as a secondary stabilizer to the ACL and helps resist internal knee rotation, whereas in only 2 of 6 sectioning studies the ALL contributed significantly to tibial internal rotation (IR). Most reconstruction studies reported that both a modified Lemaire tenodesis and an ALLR could significantly reduce the residual ALRI in isolated ACL-reconstructed knees and were able to restore IR stability/IR stability during the pivot shift.

CONCLUSIONS

The ITB acts as the main secondary stabilizer to the ACL in resisting IR/IR during pivot shift and an anterolateral corner (ALC) reconstruction with either a modified Lemaire tenodesis and ALLR can improve residual knee rotatory laxity in ACL reconstructed knees.

CLINICAL RELEVANCE

This systematic review provides insight in the biomechanical function of the ITB and ALL and emphasizes the importance of adding an ALC reconstruction to ACL reconstruction.

Female Athletes With Better Psychological Readiness Are at Higher Risk for Second ACL Injury After Primary ACL Reconstruction

BACKGROUND

Approximately 1 in 4 athletes returning to sports will sustain a second anterior cruciate ligament (ACL) injury. Psychological factors related to kinesiophobia, confidence, and psychological readiness are associated with second ACL injury; however, the evidence is conflicting.

HYPOTHESIS

Athletes who sustain a second ACL injury (ie, graft rupture or contralateral ACL rupture) within 2 years of ACL reconstruction (ACLR) would have greater kinesiophobia, less confidence, and lower psychological readiness prior to return to sport (RTS) compared with athletes who do not sustain a second ACL injury.

STUDY DESIGN

Secondary analysis of a prospective randomized trial.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 39 female Level I/II athletes completed the following measures after postoperative rehabilitation and a 10-session RTS and second ACL injury prevention program: ACL Return to Sport after Injury (ACL-RSI) scale, the 11-item Tampa Scale of Kinesiophobia (TSK-11), and question 3 on the Knee injury and Osteoarthritis Outcome Score (KOOS) quality of life (QoL) subscale. Athletes were dichotomized based on whether they sustained a second ACL injury within 2 years of ACLR or not. Independent t tests determined group differences in TSK-11, KOOS-QoL, ACL-RSI, and the 3 individual components of the ACL-RSI (ie, emotions, confidence, risk appraisal).

RESULTS

Nine athletes sustained a second ACL injury (4 graft ruptures and 5 contralateral ACL ruptures). The group that sustained a second ACL injury had higher scores on the ACL-RSI (P = 0.03), higher on the risk appraisal questions of the ACL-RSI (P < 0.01), and met RTS criteria sooner than athletes who did not (P = 0.04). All second ACL injuries occurred in athletes who underwent primary ACLR with hamstring tendon autografts.

CONCLUSION

Athletes who sustained a second ACL within 2 years of ACLR had a more positive psychological outlook, higher scores on the specific questions related to the risk appraisal construct of the ACL-RSI, and met RTS criteria sooner than athletes who did not sustain a second ACL injury.

CLINICAL RELEVANCE

Counseling athletes about delaying RTS to reduce the risk of second ACL injury may be especially important in athletes who display high psychological readiness and meet RTS criteria sooner.

Healing of acute anterior cruciate ligament rupture on MRI and outcomes following non-surgical management with the Cross Bracing Protocol

OBJECTIVE

Investigate MRI evidence of anterior cruciate ligament (ACL) healing, patient-reported outcomes and knee laxity in patients with acute ACL rupture managed non-surgically with the Cross Bracing Protocol (CBP).

METHODS

Eighty consecutive patients within 4 weeks of ACL rupture were managed with CBP (knee immobilisation at 90° flexion in brace for 4 weeks, followed by progressive increases in range-of-motion until brace removal at 12 weeks, and physiotherapist-supervised goal-oriented rehabilitation). MRIs (3 months and 6 months) were graded using the ACL OsteoArthritis Score (ACLOAS) by three radiologists. Mann-Whitney U tests compared Lysholm Scale and ACL quality of life (ACLQOL) scores evaluated at median (IQR) of 12 months (7-16 months) post-injury, and χ2 tests compared knee laxity (3-month Lachman's test and 6-month Pivot-shift test), and return-to-sport at 12 months between groups (ACLOAS grades 0-1 (continuous±thickened ligament and/or high intraligamentous signal) versus ACLOAS grades 2-3 (continuous but thinned/elongated or complete discontinuity)).

RESULTS

Participants were aged 26±10 years at injury, 39% were female, 49% had concomitant meniscal injury. At 3 months, 90% (n=72) had evidence of ACL healing (ACLOAS grade 1: 50%; grade 2: 40%; grade 3: 10%). Participants with ACLOAS grade 1 reported better Lysholm Scale (median (IQR): 98 (94-100) vs 94 (85-100)) and ACLQOL (89 (76-96) vs 70 (64-82)) scores, compared with ACLOAS grades 2-3. More participants with ACLOAS grade 1 had normal 3-month knee laxity (100% vs 40%) and returned to pre-injury sport (92% vs 64%), compared with participants with an ACLOAS grades 2-3. Eleven patients (14%) re-injured their ACL.

CONCLUSION

After management of acute ACL rupture with the CBP, 90% of patients had evidence of healing on 3-month MRI (continuity of the ACL). More ACL healing on 3-month MRI was associated with better outcomes. Longer-term follow-up and clinical trials are needed to inform clinical practice.

Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury.

Purpose

To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis.

Results

Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P < .0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P = .0005), but different results were found in male athletes. (RR, 0.81; P = .21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P = .28).

Conclusion

The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes.

Clinical Outcomes After ACL Reconstruction in Soccer (Football, Futbol) Players: A Systematic Review and Meta-Analysis

CONTEXT

The risk factors for anterior cruciate ligament (ACL) tear for athletes participating in pivoting sports includes young age and female sex. A previous meta-analysis has reported a reinjury rate of 15% after ACL reconstruction (ACLR) for athletes across all sports. To the best of the authors' knowledge, this is the first systematic review and meta-analysis of available literature reporting outcomes after ACLR in soccer players.

OBJECTIVE

To review and aggregate soccer-specific outcomes data after ACLR found in current literature to help guide a more tailored discussion regarding expectations and prognosis for soccer players seeking operative management of ACL injuries.

DATA SOURCES

A comprehensive search of publications was performed using PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SPORTDiscus databases.

STUDY SELECTION

Inclusion criteria consisted of original studies, level of evidence 1 to 4, studies reporting clinical and patient-reported outcomes (PROs) after primary ACLR in soccer players at all follow-up length.

STUDY DESIGN

The primary outcomes of interest were graft failure/reoperation rates, ACL injury in contralateral knee, return to soccer time, and PROs.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Search of literature yielded 32 studies for inclusion that involved 3112 soccer players after ACLR.

RESULTS

The overall graft failure/reoperation rate ranged between 3.0% and 24.8% (mean follow-up range, 2.3-10 years) and the combined ACL graft failure and contralateral ACL injury rate after initial ACLR was 1.0% to 16.7% (mean follow-up range, 3-10 years); a subgroup analysis for female and male players revealed a secondary ACL injury incidence rate of 27%, 95% CI (22%, 32%) and 10%, 95% CI (6%, 15%), respectively. Soccer players were able to return to play between 6.1 and 11.1 months and the majority of PROs showed favorable scores at medium-term follow-up.

CONCLUSION

Soccer players experience high ACL injury rates after primary ACLR and demonstrated similar reinjury rates as found in previous literature of athletes who participate in high-demand pivoting sports.

Anterior cruciate ligament injury occurrence, return to sport and subsequent injury in the Australian High Performance Sports System: A 5-year retrospective analysis

OBJECTIVES

To report anterior cruciate ligament (ACL) injury occurrence, return to sport (RTS) timeframes and ACL subsequent injuries recorded in the Australian High Performance Sports System according to athlete sex.

METHODS

ACL injury data of injured athletes were prospectively collected by the treating sports and exercise physicians and physiotherapists within the Australian High Performance Sports System between January 1, 2015 and May 31, 2020. RTS time frames for ACL injuries and the proportion of subsequent ACL injuries were calculated. The RTS time was compared between sexes, age groups and ACL injury categories using the Mann-Whitney U test and the Kruskal-Wallis test.

RESULTS

A total of 132 ACL injuries were reported in 108 athletes (77 female, 31 male). ACL injuries accounted for 6.4% of all reported knee injuries, with almost half (48.5%) of the ACL injuries reported to occur during training. Median RTS time was 369 days (IQR = 273-487), with RTS times reducing with increasing age (X2 (Zbrojkiewicz et al., 2018) = 11.781, p = 0.008). The presence of concurrent knee pathology did not significantly affect the RTS timeframes. ACL injuries were most frequently reported in netball, winter sports, basketball, field hockey and gymnastics. One quarter of the ACL reported (n = 34, 25.8%) were subsequent to a prior ACL injury, with the majority of these injuries occurring to the ipsilateral knee (n = 26) as opposed to contralateral knee (n = 6).

CONCLUSIONS

Despite ACL injuries accounting for a small proportion of all knee injuries reported in the Australian High Performance Sports System, more than a quarter are subsequent to a previous ACL injury. Shorter RTS times were observed in older athletes; however, considerable periods of time-loss occur as a consequence of ACL injuries. Effective primary prevention, rehabilitation processes, and ongoing tertiary prevention strategies are warranted in this population.

Clinical outcomes of different autografts used for all-epiphyseal, partial epiphyseal or transphyseal anterior cruciate ligament reconstruction in skeletally immature patients - a systematic review

BACKGROUND

Different types of grafts can be used for anterior cruciate ligament reconstruction (ACLR). There is little published data regarding skeletally immature patients. The purpose of this systematic review was to assess the clinical outcomes and complications for different autograft types used in all-epiphyseal, transphyseal and partial epiphyseal/hybrid ACLR in skeletally immature children and adolescents.

METHODS

PubMed, Embase and Cochrane databases were systematically searched for literature regarding ACLR using hamstrings, quadriceps or bone-patellar-tendon-bone (BPTB) autografts in skeletally immature patients. Studies were included if they examined at least one of the following outcomes: graft failure, return to sport(s), growth disturbance, arthrofibrosis or patient reported outcomes and had a minimum follow-up of 1 year. Case reports, conference abstracts and studies examining allografts and extra-articular or over-the-top ACL reconstruction techniques were excluded. Graft failure rates were pooled for each graft type using the quality effects model of MetaXL. A qualitative synthesis of secondary outcomes was performed.

RESULTS

The database search identified 242 studies. In total 31 studies were included in this review, comprising of 1358 patients. Most patients (81%) were treated using hamstring autograft. The most common used surgical technique was transphyseal. The weighted, pooled failure rate for each graft type was 12% for hamstring tendon autografts, 8% for quadriceps tendon autografts and 6% for BPTB autografts. Confidence intervals were overlapping. The variability in time to graft failure was high. The qualitative analysis of the secondary outcomes showed similar results with good clinical outcomes and low complication rates across all graft types.

CONCLUSIONS

Based on this review it is not possible to determine a superior graft type for ACLR in skeletally immature. Of the included studies, the most common graft type used was the hamstring tendon. Overall, graft failure rates are low, and most studies show good clinical outcomes with high return to sports rates.

Generalised joint hypermobility leads to increased odds of sustaining a second ACL injury within 12 months of return to sport after ACL reconstruction

OBJECTIVES

To determine the 12-month risk of a second anterior cruciate ligament (ACL) injury in a population of patients with and without generalised joint hypermobility (GJH) who return to sports (RTS) at competition level after ACL reconstruction (ACL-R).

METHODS

Data were extracted from a rehabilitation-specific registry for 16-50-year-old patients treated with ACL-R between 2014 and 2019. Demographics, outcome data and the incidence of a second ACL injury within 12 months of RTS, defined as a new ipsilateral or contralateral ACL, were compared between patients with and without GJH. Univariable logistic regression and Cox proportional hazards regression were performed to determine the influence of GJH and time of RTS on the odds of a second ACL injury, and ACL-R survival without a second ACL injury after RTS.

RESULTS

A total of 153 patients, 50 (22.2%) with GJH and 175 (77.8%) without GJH, were included. Within 12 months of RTS, 7 (14.0%) patients with GJH and 5 (2.9%) without GJH had a second ACL injury (p=0.012). The odds of sustaining a second ipsilateral or contralateral ACL injury were 5.53 (95% CI 1.67 to 18.29) higher in patients with GJH compared with patients without GJH (p=0.014). The lifetime HR of a second ACL injury after RTS was 4.24 (95% CI 2.05 to 8.80; p=0.0001) in patients with GJH. No between-group differences were observed in patient-reported outcome measures.

CONCLUSION

Patients with GJH undergoing ACL-R have over five times greater odds of sustaining a second ACL injury after RTS. The importance of joint laxity assessment should be emphasised in patients who aim to return to high-intensity sports following ACL-R.

Knee extensor torque-velocity relationships following anterior cruciate ligament reconstruction

BACKGROUND

The inherent nature of the torque-velocity relationship is the inverse nature between the velocity of muscle contraction and torque production and is an indication of muscle function. The purpose of this study was to characterize the torque-velocity relationship in the quadriceps following anterior cruciate ligament reconstruction compared to healthy limbs.

METHODS

681 participants were included, 493 of which were patients at least four months following anterior cruciate ligament reconstruction (23.2 ± 10.08 yr, 6.6 ± 5.37 months post-surgery) and 188 were healthy participants (21.6 ± 3.77 yr). A subset of 175 post-surgical participants completed a repeated visit (8.1 ± 1.71 months post-surgery). Participants completed isokinetic knee extension at 90°/s and 180°/s. A one-way ANOVA was used to compare torque velocity relationships by limb type (surgical, contralateral, healthy). Paired samples t-tests were conducted to analyze the torque-velocity relationship across limbs and across time.

FINDINGS

There was a large effect for limb type on torque-velocity (F(2, 1173) = 146.08, p < 0.001, η2 = 0.20). Surgical limbs demonstrated significantly lower torque-velocity relationships compared to the contralateral limbs (ACLR: 0.26 Nm/kg, contralateral:0.55 Nm/kg, p < 0.001, d = 1.18). Healthy limbs had similar torque-velocity relationships bilaterally (dominant limb: 0.48 Nm/kg, non-dominant limb: 0.49 Nm/kg, p = 0.45). The torque velocity relationship for the involved limb significantly increased in magnitude over time (+0.11 Nm/kg, p < 0.001, d = -0.61) while the contralateral limb torque-velocity relationship remained stable over time (0.0 Nm/kg difference, p = 0.60).

INTERPRETATION

Following surgery, the knee extensors appear to have altered torque-velocity relationships compared to contralateral and healthy limbs. This may indicate a specific target for assessment and rehabilitation following surgery.

Allograft Anterior Cruciate Ligament Reconstruction Fails at a Greater Rate in Patients Younger Than 34 Years

Purpose

To characterize the secondary anterior cruciate ligament (ACL) injury rates after primary allograft anterior cruciate ligament reconstruction (ACLR) and to identify the age cut-score at which the risk of allograft failure decreases.

Methods

All patients who underwent primary ACLR within a single orthopaedic department between January 2005 and April 2020 were contacted at a minimum of 2 years post-ACLR to complete a survey regarding complications experienced post-surgery, activity level, and perceptions of knee health. Patients were excluded for incidence of previous ACLR (ipsilateral or contralateral) and/or age younger than 14 years. Relative proportions were calculated, binary regression analysis was performed, and receiver operating characteristic analysis was used to identify the threshold age for maximal sensitivity and specificity to predict high risk of allograft failure, defined as undergoing revision ACLR.

Results

Of the 939 surveys completed, 398 patients underwent primary allograft ACLR (mean age 39.5 years; range 16.0-66.1 years; 54.3% female). The secondary ACL injury rate was 11.6% (5.8% ipsilateral revision ACLR, 5.8% contralateral ACL injury). Male and female patients had similar revision (5.5% male, 6.0% female, P = .82) and contralateral ACL injury rates (6.6% male, 5.1% female, P = .52). Receiver operating characteristic analysis indicated that age ≤34 years was threshold for differentiating high risk of allograft failure (area under the curve 0.65, 95% confidence interval 0.55-0.76; P = .014). Patients aged ≤34 years had a greater secondary injury rate than patients >34 years (20.4% (10.2% revision ACLR, 10.2% contralateral ACL injury) versus 6.9% (3.5% revision ACLR, 3.5% contralateral ACL injury; P < .001). Binary regression analysis demonstrated that decreasing age was associated with increased risk of graft failure (χ2 = 7.9, P = .02.).

Conclusions

Allograft ACLR showed similar failure rates between sexes but displayed suboptimal graft failure outcomes in younger and active patients. By age 34 years, the increased revision risk for younger patients diminished.

Level of Evidence

Level IV, therapeutic case series.

Concomitant Injuries Associated With ACL Rupture in Elite Professional Alpine Ski Racers and Soccer Players: A Comparative Study With Propensity Score Matching Analysis

Background

For elite professional soccer players and alpine skiers, injuries associated with anterior cruciate ligament (ACL) rupture, such as meniscal, cartilage, or collateral ligament lesions, could result in a delayed return to sport compared with isolated ACL injury.

Purpose/Hypothesis

The purpose of the study was to provide a detailed description of associated injuries at the time of primary ACL reconstruction in elite soccer players and alpine skiers. It was hypothesized that soccer players and skiers would present different typical injury patterns due to different injury mechanisms.

Study Design

Cohort study; Level of evidence, 3.

Methods

Surgical reports and arthroscopic images of elite professional soccer players and alpine skiers who underwent primary ACL reconstruction at a single institution between January 2010 and June 2022 were analyzed retrospectively. The presence and location of multiligamentous injury, meniscal tears, and chondral lesions were compared between the athlete groups. A propensity score matching analysis with 1:1 ratio was performed between skiers and soccer players to limit the effect of selection bias.

Results

Included were ACL reconstruction data representative of 37 soccer players and 44 alpine skiers. Meniscal pathology was found in 32 (86%) soccer players and 30 (68%) skiers. Chondral injuries were reported in 11 (30%) soccer players and 15 (34%) skiers. Results of the propensity score matching analysis in 15 pairs of soccer players and skiers indicated that soccer players had a significantly higher rate of medial meniscal injuries (73% vs 27%; P = .03) and lateral posterior root tears (33% vs 0%; P = .04) compared with skiers.

Conclusion

A higher prevalence of combined chondral and meniscal injuries versus isolated ACL injuries was observed in both groups of athletes. Professional soccer players were characterized by higher prevalence of medial meniscal tears and lateral posterior root lesions compared with professional alpine skiers.

Influence of Graft Type on Lower Extremity Functional Test Performance and Failure Rate After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population.

OBJECTIVE

To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)].

STUDY DESIGN

Cross-sectional.

LEVEL OF EVIDENCE

Level 2.

METHODS

Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures.

RESULTS

Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB (P = 0.045).

CONCLUSION

After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure.

CLINICAL RELEVANCE

Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure.

Postoperative considerations based on graft type after anterior cruciate ligament reconstruction a narrative review

Background and Objective

Graft selection for anterior cruciate ligament reconstruction (ACLR) affects rehabilitation throughout the course of postoperative care.

Methods

A search of PubMed and EBSCO was performed and abstracts independently reviewed by two authors. This search was also supplemented with additional evidence relevant to each phase of ACLR rehabilitation.

Key Content and Findings

Direct implications of graft type on clinical decisions vary throughout treatment phases, transitioning from potential differences in acute postoperative pain management immediately after surgery to facilitating sufficient and appropriate lower extremity loading in subsequent weeks. Regardless of graft type, surgical limb weakness persists throughout the course of rehabilitation; however, harvest site selection for autografts contributes to disproportionate weakness of the harvested muscle group and the potential for surgical-induced tendinopathy. In later phases of rehabilitation, as athletes are transitioning into return to sport (RTS), treatment decisions and protocols are less affected by graft type but expectations for meeting clinical milestones and the time required to do so does differ between graft types.

Conclusions

Targeted strengthening interventions to address muscle weakness following graft harvest in autografts should be continued throughout the rehabilitation process. Lingering deficits in quadriceps strength symmetry may also influence time to meet progression and RTS criteria following graft harvest from the extensor mechanism.

Training interventions to reduce the risk of injury to the lower extremity joints during landing movements in adult athletes: a systematic review and meta-analysis

Objective

Aim of this systematic review was to summarise training interventions designed to reduce biomechanical risk factors associated with increased risk of lower extremity landing injuries and to evaluate their practical implications in amateur sports.

Design

Systematic review and meta-analysis.

Data sources

MEDLINE, Scopus and SPORTDiscus.

Eligibility criteria

Training intervention(s) aimed at reducing biomechanical risk factors and/or injury rates included the following: (1) prospective or (non-)randomised controlled study design; (2) risk factors that were measured with valid two-dimensional or three-dimensional motion analysis systems or Landing Error Scoring System during jump landings. In addition, meta-analyses were performed, and the risk of bias was assessed.

Results

Thirty-one studies met all inclusion criteria, capturing 11 different training interventions (eg, feedback and plyometrics) and 974 participants. A significantly medium effect of technique training (both instruction and feedback) and dynamic strengthening (ie, plyometrics with/without strengthening) on knee flexion angle (g=0.77; 95% CI 0.33 to 1.21) was shown. Only one-third of the studies had training interventions that required minimal training setup and additional coaching educations.

Conclusion

This systematic review highlights that amateur coaches can decrease relevant biomechanical risk factors by means of minimal training setup, for example, instructing to focus on a soft landing, even within only one training session of simple technique training. The meta-analysis emphasises implementing technique training as stand-alone or combined with dynamic strengthening into amateur sport training routine.

Effect of Age and Sex on Psychological Readiness and Patient-Reported Outcomes 6 Months After Primary ACL Reconstruction

Background

Successful return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR) can be affected by a patient's physical and psychological state throughout the rehabilitation process.

Purpose

To prospectively compare differences in patients at 6 months after primary ACLR with the ACL-Return to Sport after Injury (ACL-RSI), International Knee Documentation Committee (IKDC) or pediatric (Pedi)-IKDC, Hospital for Special Surgery Pediatric Functional Activity Brief Scale (Pedi-FABS), and Patient-Reported Outcomes Measurement Information System-Psychological Stress Experiences (PROMIS-PSE) scores.

Study Design

Prospective cohort study; Level of evidence, 2.

Methods

Patients enrolled were 8 to 35 years old who underwent primary ACLR and had their 6-month follow-up appointments between December 2018 and March 2020. Patients were divided into 3 age groups as follows: (1) preadolescents (10-14 years); (2) adolescents (15-18 years); and (3) adults (>18 years). Outcomes on the ACL-RSI, IKDC/Pedi-IKDC, Pedi-FABS, and PROMIS-PSE were compared according to age group, graft type (hamstring, patellar tendon, quadriceps, or iliotibial band autograft), and sex.

Results

A total of 176 patients (69 male, 107 female), with a mean age of 17.1 ± 3.1 years were included in the study. The mean ACL-RSI scores were significantly different among age groups (preadolescents, 75 ± 18.9; adolescents, 61.5 ± 20.4; and adults, 52.5 ± 19.8 [P < .001]) and graft types (P = .024). The IKDC and PROMIS-PSE scores were also significantly different among age groups (P < .001 and P = .044, respectively) and graft types (P = .034 and P < .001, respectively), with the iliotibial graft and the younger age group performing the best. There was no significant difference in the Pedi-FABS either by age group (P = .127) or graft type (P = .198). Female patients had lower ACL-RSI scores and higher (worse) scores on PROMIS-PSE than their male counterparts (P = .019 and P < .001, respectively), with no sex-based differences on IKDC or Pedi-FABS scores. The ACL-RSI and IKDC were positively correlated (Spearman r = 0.57; P < .001), while the ACL-RSI and PROMIS-PSE were negatively correlated (Pearson r = -0.34; P < .001).

Conclusion

This study suggests that psychological profiles and subjective perceptions of knee function 6 months after ACLR may vary in patients of different ages and between the sexes. Preadolescent patients had better scores on a majority of patient-reported outcomes compared with adolescent and adult patients.

Lower Patellofemoral Joint Contact Force During Side-Step Cutting After Return-to-Sports Clearance Anterior Cruciate Ligament Reconstruction

BACKGROUND

Low patellofemoral joint (PFJ) contact force has been associated with PFJ osteoarthritis. Quadriceps force and knee flexion angles, which are typically altered after an anterior cruciate ligament reconstruction (ACLR), primarily influence PFJ contact forces. It is still inconclusive whether differences in PFJ contact forces are present during high knee flexion tasks such as side-step cutting after clearance to return to sports (RTS) after ACLR.

PURPOSE

To explore PFJ contact forces in the ACLR limb and compare them with those of the contralateral and control limbs during side-step cutting tasks after clearance to RTS.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 26 male athletes with ACLR who were previously cleared to RTS were matched with 23 healthy men serving as the control group. Three-dimensional motion capture and force plate data were collected while both groups performed anticipated side-step cutting tasks. Joint kinematics, kinetics, muscle forces, and PFJ contact forces were calculated using musculoskeletal modeling.

RESULTS

Peak PFJ force was lower in the ACLR limbs compared with the contralateral limbs (mean difference [MD], 5.89 body weight [BW]; 95% CI, 4.7-7.1 BW; P < .001) and the control limbs (MD, 4.44 BW; 95% CI, 2.1-6.8 BW; P < .001). During peak PFJ force, knee flexion angle was lower in ACLR limbs compared with the contralateral (MD, 4.88°; 95% CI, 3.0°-6.7°; P < .001) and control (MD, 6.01°; 95% CI, 2.0°-10.0°; P < .002) limbs. A lower quadriceps force compared with the contralateral (MD, 4.14 BW; 95% CI, 3.4-4.9 BW; P < .001) and control (MD, 2.83 BW; 95% CI, 1.4-4.3 BW; P < .001) limbs was also found.

CONCLUSION

Lower PFJ contact forces and a combination of quadriceps force deficits and smaller knee flexion angle were found in the ACLR compared with the contralateral and control limbs even after clearance to RTS.

CLINICAL RELEVANCE

Despite rehabilitation and subsequent clearance to RTS, differences in PFJ contact forces are present after ACLR. Current rehabilitation and RTS battery may not be effective and sensitive enough to identify and address these differences.

A scoping review of portable sensing for out-of-lab anterior cruciate ligament injury prevention and rehabilitation

Anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) surgery are common. Laboratory-based biomechanical assessment can evaluate ACL injury risk and rehabilitation progress after ACLR; however, lab-based measurements are expensive and inaccessible to most people. Portable sensors such as wearables and cameras can be deployed during sporting activities, in clinics, and in patient homes. Although many portable sensing approaches have demonstrated promising results during various assessments related to ACL injury, they have not yet been widely adopted as tools for out-of-lab assessment. The purpose of this review is to summarize research on out-of-lab portable sensing applied to ACL and ACLR and offer our perspectives on new opportunities for future research and development. We identified 49 original research articles on out-of-lab ACL-related assessment; the most common sensing modalities were inertial measurement units, depth cameras, and RGB cameras. The studies combined portable sensors with direct feature extraction, physics-based modeling, or machine learning to estimate a range of biomechanical parameters (e.g., knee kinematics and kinetics) during jump-landing tasks, cutting, squats, and gait. Many of the reviewed studies depict proof-of-concept methods for potential future clinical applications including ACL injury risk screening, injury prevention training, and rehabilitation assessment. By synthesizing these results, we describe important opportunities that exist for clinical validation of existing approaches, using sophisticated modeling techniques, standardization of data collection, and creation of large benchmark datasets. If successful, these advances will enable widespread use of portable-sensing approaches to identify ACL injury risk factors, mitigate high-risk movements prior to injury, and optimize rehabilitation paradigms.

Quadriceps strength is an early indicator of return to competitive sports 1 year after anterior cruciate ligament reconstruction in adult amateur athletes

BACKGROUND

Return to sports is one of the important reasons why athletes with an anterior cruciate ligament (ACL) injury undergo surgery. There are few reports on return to sports among adult amateur athletes (individuals older than the college age who participate in competitive sports). This study aimed to investigate the return of adult amateur athletes to competitive sports 1 year after ACL reconstruction and to identify the indicators for return to competitive sports.

METHODS

Between January 2015 and December 2017, adult amateur athletes who underwent primary ACL reconstruction were retrospectively investigated. The rate of return to competitive sports 1 year after surgery was evaluated. The patients were categorized into two groups: return to sports group (R group) and non-return to sports group (N group). Pre- and postoperative range of motion, pivot-shift test, anteroposterior laxity, quadriceps strength, Lysholm score, and the International Knee Documentation Committee score were compared between the groups.

RESULTS

This study included 78 patients (48 men, 30 women; age range, 22-53 years). Five months after ACL reconstruction, quadriceps strength was significantly lower in the N group than in the R group, denoting muscle weakness in the N group at that time. No significant differences were found in the other items between the groups preoperatively and 1 year after surgery.

CONCLUSION

In this study, the rate of return to competitive sports of adult amateur athletes 1 year after ACL reconstruction was 76.9%. Quadriceps strength may be an early indicator of return to competitive sports 1 year after reconstruction.

Clinical Outcomes of Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-articular Tenodesis Procedures in Skeletally Immature Patients: A Systematic Review From the SANTI Study Group

BACKGROUND

The treatment of anterior cruciate ligament (ACL) tears in the pediatric population has changed significantly in the past few decades. Pediatric patients who underwent ACL reconstruction (ACLR) have a high risk of rerupture of up to 32%. The addition of lateral extra-articular procedures [lateral extra-articular tenodesis (LET)], already shown to be effective in reducing the risk of rerupture in adults, may also be effective in pediatric patients. The purpose of this study was to systematically review the clinical outcomes of ACLR+LET tenodesis in pediatric patients.

METHODS

Data were collected from Pubmed, MEDLINE, Cochrane, and Scopus Databases according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Studies reporting the clinical outcomes of ACLR+LET in the pediatric population using autograft, return to play, growth disturbances, failure rate, and surgical complications were included.

RESULTS

A total of 5 studies comprising 381 pediatric patients were included. Three main surgical techniques with common features were used. The mean age of all pediatric patients in the included studies was 11.73 years (range, 5.6 to 16) with a mean follow-up of 50.1 months. The overall graft failure rate of the included studies was 4.65%. The return to play was 95.11%. The mean Lysholm score was 94.51 and the mean Pediatric International Knee Documentation Committee (Pedi-IKDC) was 93.39. In all, 1.9% of the patients had a coronal plane deformity and 0.8% had a limb length discrepancy. 4.6% of the patients had a contralateral ACL tear.

CONCLUSIONS

A combined ACLR+LET in pediatric patients showed a graft failure ranging from 0% to 13.6% at a mean follow-up of 50.1 months. This low graft failure rate is consistent with ACLR+LET in adults. Further investigations are needed to validate these findings and the potential role of LET in reducing graft rupture rates in this population.

LEVEL OF EVIDENCE

Level IV-systematic review of level IV studies.

Clinical and arthroscopic outcomes of single-bundle anterior cruciate ligament reconstruction using autologous hamstrings augmented with ligament augmentation and reconstruction systems compared with four-strand hamstring tendon grafts alone

PURPOSE

To compare the clinical, radiological, and second-look arthroscopic outcomes in patients who underwent anterior cruciate ligament (ACL) reconstruction using a four-strand hamstring tendon graft (hamstring group) either without augmentation or with ligament augmentation and reconstruction system (LARS) augmentation (LARS augmentation group).

METHODS

From January 2018 to December 2019, patients who underwent ACL reconstruction were included. Patient-reported outcome measures (PROMs) were undertaken pre-operatively and at three, six, 12, and 24 months post-operatively. Arthroscopic evaluation was performed focusing on the morphology of the graft based on graft tension, graft tear, and synovial coverage.

RESULTS

A total of 178 consecutive patients received single-bundle ACL reconstruction, 89 patients in each group, and 20 patients were lost to follow-up in the first two years. At the three month follow-up, the LARS augmentation group had significantly higher Lysholm scores, IKDC scores, and KOS-ADLS scores than the hamstring group (P < 0.001). At the three, six and 12-month follow-ups, there were significantly higher Tegner scores and ACL-RSI scores in the LARS augmentation group than in the hamstring group (P < 0.05). At the three and six month follow-ups, the LARS augmentation group had significantly higher rates of return to sports and return to sports at their preinjury level (P < 0.05). There were no between-group differences in other outcomes, including arthroscopic outcomes, graft signal intensity, post-operative complications or rerupture rates.

CONCLUSIONS

Autologous hamstring augmented with the LARS augmentation technique provides good and realistic clinical and functional results during the early post-operative period with high levels of satisfaction of patients, including participation in sports and physical activity, and high rates of return to sports at the preinjury level, without any apparent complications compared with hamstring ACL reconstruction alone. No increases in complication, reinjury rates, or increased lateral laxity were observed at the 12-month or 24-month follow-up.

Return to Sports: A Risky Business? A Systematic Review with Meta-Analysis of Risk Factors for Graft Rupture Following ACL Reconstruction

BACKGROUND

The risk of sustaining a graft rupture after anterior cruciate ligament reconstruction (ACLR) is high. Contributing risk factors are, however, still not clearly identified.

OBJECTIVE

The aim of this systematic review was to identify and quantify risk factors for graft rupture after ACLR.

METHODS

A systematic review with meta-analysis (PROSPERO CRD42020140129) based on PRISMA guidelines was performed. MEDLINE, CINAHL and EMBASE were searched from inception to September 2021. Prospective and retrospective studies addressing risk factors for graft rupture after ACLR in males/females of all ages were considered. Meta-analyses using a random effect model (effect measure: odds ratio [OR] with 95% confidence interval [CI]) were performed. The GRADE tool was used to assess evidence quality.

RESULTS

Following full-text screening of 310 relevant papers, 117 were eventually included, incorporating up to 133,000 individuals in each meta-analysis. Higher Tegner activity level (≥ 7 vs < 7) at primary injury (OR 3.91, 95% CI 1.69-9.04), increased tibial slope (degrees) (OR 2.21, 95% CI 1.26-3.86), lower psychological readiness to return to sport (RTS) (OR 2.18, 95% CI 1.32-3.61), early surgery (< 12 vs ≥ 12 months) (OR 1.87, 95% CI 1.58-2.22), RTS (pre-injury level) (OR 1.87, 95% CI 1.21-2.91) and family history of ACL injury (OR 1.76, 95% CI 1.34-2.31) were all associated with increased odds of graft rupture. Higher age (OR 0.47, 95% CI 0.39-0.59), female sex (OR 0.88, 95% CI 0.79-0.98), fewer self-reported knee symptoms pre-reconstruction (OR 0.81, 95% CI 0.69-0.95) and concomitant cartilage injuries (OR 0.70, 95% CI 0.62-0.79) instead decreased the odds. Meta-analysis revealed no association between body mass index, smoking, joint laxity, RTS time, knee kinematics, muscle strength or hop performance and graft rupture.

CONCLUSION

Conspicuous risk factors for graft rupture were mainly sports and hereditary related. Few studies investigated function-related modifiable factors or included sports exposure data.

Deficits in Dynamic Balance and Hop Performance Following ACL Reconstruction Are Not Dependent on Meniscal Injury History

Background

Athletes often exhibit persistent deficits in dynamic balance and hop performance in their involved limb following ACL reconstruction. However, it is unclear how meniscal injury history affects inter-limb asymmetry.

Purpose

The purpose of this study was to compare inter-limb asymmetry in dynamic balance and hop performance in athletes with and without a history of concomitant meniscal injury.

Study Design

Cross-sectional study.

Methods

Dynamic balance and hop test data were analyzed for 34 adolescent athletes who had undergone ACL reconstruction; 19 athletes had sustained an isolated ACL tear, while 15 had sustained an ACL tear along with a meniscus injury. Athletes who had sustained a meniscus injury were sub-divided into those who underwent a meniscal repair (n = 9) versus a partial meniscectomy (n = 6). Dynamic balance was assessed using the Y-Balance Test, while hop performance was assessed using the single and triple hop tests. Data were recorded at the time of return-to-sport testing (5-11 months post-surgery). For each variable, mixed-model analysis of variance, with a between-subjects factor of group (isolated ACL tear, meniscal repair, partial meniscectomy) and a within-subjects factor of limb (involved, uninvolved), was conducted.

Results

The groups exhibited similar degrees of inter-limb asymmetry in dynamic balance and hop test performance, as there was not a group-by-limb interaction effect for the Y-Balance Test distances (p ≥ 0.43) or hop test distances (p ≥ 0.96). However, there was a main effect of limb for the anterior and posteromedial Y-Balance Test distances and the single and triple hop test distances (p ≤ 0.004). For each variable, performance was worse for the involved limb, compared to the uninvolved limb.

Conclusion

It appears that deficits in dynamic balance and hop performance among adolescent athletes who have undergone ACL reconstruction are not dependent on meniscal injury/surgery history.

Level of Evidence

3.

ACL Reconstruction and Modified Lemaire Tenodesis Utilizing Common Suspensory Femoral Fixation

Persistent rotatory instability after anterior cruciate ligament (ACL) reconstruction has been well studied and recognized as the cause of unsatisfactory clinical results. Various anterolateral techniques have been described as an adjunct to the ACL reconstruction to improve clinical outcomes. Modified deep Lemaire lateral extra-articular tenodesis has been tested both biomechanically and clinically and proved an efficient solution in controlling tibia internal rotation, when performed in conjunction with ACL reconstruction. We describe a simple, versatile, effective, and reproducible technique of lateral extra-articular tenodesis, using common suspensory femoral fixation, with no additional cost and surgical risk.