Secondary Anterior Cruciate Ligament Research Articles

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

ACL Research Retreat IX Summary Statement: The Pediatric Athlete, March 17-19, 2022; High Point, North Carolina.

ACL Research Retreat IX March 17–19, 2022 High Point, NC

ACL Research Retreat IX March 17–19, 2022 High Point, NC

Epidemiology of recurrent anterior cruciate ligament injuries according to sport type

The anterior cruciate ligament (ACL) is one of the two cruciate ligaments that helps to strengthen the knee joint. It is a common knee injury, which often occurs in sports players. There is no bias against age or gender; however, it has been suggested in literature that women are at increased risk of secondary ACL injury. These injuries can have serious consequences for an injured athlete, including high medical costs, long off playing time, and an elevated chance of developing early osteoarthritis. Recurrent ACL injuries are described as injuries that occur in the same knee which has been previously treated. A recurrent ACL may be the result of a severe injury to the same position, graft failure, or an improper surgical procedure. Studies have reported significant prevalence of recurrent ACL. The purpose of this research is to review the available information about the epidemiology of recurrent ACL injuries. Athletes returning to sports field within two years of injury have higher chance of recurrent ACL injury. Variable prevalence of recurrent ACL injuries is reported in literature and limited studies are available. The young age, high level of exposure to physical activity, and the use of allograft all increase the chances of further ACL injury. Future population-based epidemiological studies can be beneficial and are need of time.

Pre-operative knee extensor and flexor torque after secondary ACL rupture: a comparative retrospective analysis

BackgroundSecondary anterior cruciate ligament (ACL) ruptures are a relevant clinical concern after surgical treatment of a primary ACL rupture. However, there is a lack of scientific evidence related to the role of muscle strength prior to revision surgery in a second ACL rupture. The aim of this study was to assess differences in knee extensor and flexor strength in patients before primary and secondary ACL reconstruction compared to healthy controls.MethodsIn total, n = 69 age, weight and sex matched individuals were included in the study: n = 23 patients with isolated primary ACL rupture, n = 23 with secondary ACL rupture, and n = 23 matched healthy controls. Maximal isokinetic knee extension and flexion torque normalized to body mass was assessed for both legs.ResultsFor patients with secondary ACL ruptures, torques were reduced in the non-injured (extension: 1.94 Nm/kg vs. 2.46 Nm/kg, p < 0.05, flexion: 1.25 Nm/kg vs. 1.59 Nm/kg, p < 0.05) and the injured leg (extension: 1.70 Nm/kg vs. 2.46 Nm/kg, p < 0.05, flexion: 1.14 Nm/kg vs. 1.59 Nm/kg, p < 0.05) compared to healthy controls. For patients with a primary ACL rupture torques were reduced in the non-injured (extension: 1.92 Nm/kg vs. 2.46 Nm/kg, p < 0.05, flexion: 1.24 Nm/kg vs. 1.59 Nm/kg, p < 0.05) and the injured leg (extension: 1.38 Nm/kg vs. 2.46 Nm/kg, p < 0.05, flexion: 1.01 Nm/kg vs. 1.59 Nm/kg, p < 0.05) compared to healthy controls. There were no differences between patients with primary and secondary ruptures, except of the knee extension on the injured leg showing higher values after a secondary ACL rupture (1.38 Nm/kg vs. 1.70 Nm/kg, p < 0.05).ConclusionsThe findings indicate that maximal knee torques were significantly reduced in patients with primary and secondary ACL ruptures before surgical reconstruction for the non-injured and injured leg as compared to healthy controls. Further investigations are needed to assess strength abilities before and after a second revision within a prospective design.

Postoperative complications following ACL reconstruction: Prevention and management

This article aims to conduct a literature analysis on the current care and prevention strategies for postoperative problems following the repair of the anterior cruciate ligament (ACL). A presentation will be given on current trends in rehabilitation procedures, suggestions for interventions, and anticipated milestones in the healing process after ACL surgery. In recent years, protocols for ACL repair have progressed to a criterion-based progression rather than a tissue healing time frame. Because of advancements in ACL surgical reconstruction techniques and rehabilitation protocols, the danger of postoperative complications can manifest itself at any point during the recovery process. This includes both the beginning and the end of the process. In this paper, we will examine the significance of preventative measures for postoperative patient who has undergone ACL repair. Infection and loss of knee motion and strength are short-term complications that can occur after an ACL reconstruction. Long-term complications can include a secondary ACL injury to either the involved knee or the contralateral knee and the inability to return to high-level sports after this procedure. The multifaceted causes of secondary ACL injuries and the limited capacity of patients to return to high-level activities should continue to be the focus of future research.

Paediatric reference anatomy for ACL reconstruction and secondary anterolateral ligament or lateral extra-articular tenodesis procedures

ObjectivesFor iliotibial band (ITB) lateral extra-articular tenodesis or anterolateral ligamentous/capsular reconstruction with anterior cruciate ligament reconstruction, a clear understanding of the referenced anterolateral knee anatomy is critical—especially given the risk of injury to the physis or key anterolateral structures in the paediatric population, which is at high-risk for primary and secondary anterior cruciate ligament injury. The purpose of this study was to quantitatively assess the anatomy of the knee physes, paediatric lateral collateral ligament (LCL) origin, popliteus origin and ITB tibial insertion. MethodsNine paediatric cadaveric knee specimens with average age 4.2 years (range 2 months–10 years) underwent dissection to identify the LCL's and popliteus’ femoral origins and the ITB's tibial insertion. Metallic marking pins demarcated precise anatomic attachment sites, and subsequent computerised tomography scans enabled quantified measurements among them. ResultsLCL & Popliteus: On the femur, the popliteus origin lay consistently deep to the LCL and inserted both distally and anteriorly to the LCL, a mean distance of 4.6 mm (range 1.9–7.6; standard deviation 2.0). From the joint line, the LCL lay a mean distance of 12.5 mm proximally while the popliteus measured a mean of 8.2 mm. Both were consistently distal to the physis. The LCL was a mean distance of 4.4 mm (range 1.0–9.5) and the popliteus was a mean distance of 8.2 (range 1.7–12.5) from the physis. ITB insertion: The ITB insertion at Gerdy's tubercle had an average footprint measuring 28.2 mm2 (range 10.3–58.4) and the ITB centre lay proximal to the physis in 6 specimens (mean age 4.2 years, median 2.5 years) and distal in 3 specimens (mean age 1.5 years, median 4 months). Mean distance from the footprint centre to the physis was 1.6 mm proximal (range 7.1 proximal – 2.2 distal). ConclusionThis study describes relative and quantitative positions of the femoral LCL and popliteus origins and tibial ITB attachment and their respective physeal relationships. Knowledge of paediatric anterolateral knee anatomy will help guide essential future research and procedures providing extra-articular anterolateral rotatory stabilisation and may help reduce iatrogenic physeal injury risk. Level of evidenceN/A (descriptive anatomic study).

Knee Strength Outcomes in Adolescents by Age and Sex During Late-Stage Rehabilitation After Anterior Cruciate Ligament Reconstruction

Background:The incidence of anterior cruciate ligament (ACL) injuries have been consistently increasing in adolescents, with those who return to competitive sport having up to a 32% risk of a secondary ACL injury. There is limited evidence regarding knee strength outcomes in young adolescents following ACL reconstruction during late-stage rehabilitation when compared to older patient groups.Purpose:The purpose of this study was to 1) establish normative knee strength values according to age group in adolescent female and male patients during late-stage rehabilitation following ACLR and 2) determine whether strength differences exist between age groups.Methods:A retrospective review of adolescent patients who underwent primary ACL reconstruction was performed. Patients completed a standardized isokinetic (60°/sec) knee extension and flexion strength assessment during late-stage rehabilitation. Peak torque was normalized to the patient’s body mass (Nm/kg) and used to calculate Limb Symmetry Index (LSI). Analyses were conducted separately for female and male cohorts and grouped by early (11-14 years) and middle (15-17 years) adolescence. An independent samples t-test examined strength differences between age groups.Results:130 females (age=15.4 ± 1.4 years; days since surgery=239.0 ± 84.4) and 112 males (age=15.4 ± 1.5 years; days since surgery= 232.6 ± 91.2) were included. Normalized knee extension peak torque on the involved limb was reported for female (1.5 Nm/kg) and male (1.8 Nm/kg) cohorts. Differences between age groups in knee extension peak torque were found on the surgical and nonsurgical limbs in female (p = 0.02 – 0.05) and male (p<0.001 – 0.002) cohorts. No differences were found between age groups for either cohort when normalized to body mass (p = 0.30 – 0.89). Post hoc power analyses revealed 67% statistical power in the female cohort and 97% in the male cohort with an alpha level set to 0.05 based on the observed effect size for the differences in isokinetic knee extension/flexion peak torque between age groups.Conclusion:Early adolescents produced less knee extension and flexion peak torque compared to middle adolescents after ACLR, but no differences were found between age groups when normalized to body mass for female or male cohorts. Normalized knee extension strength in young adolescents may differ from older patients and should be considered in the rehabilitation process.TABLE 1:Patient Demographics - FemalesTABLE 2:Patient Demographics - MalesTABLE 3:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Females)TABLE 4:Strength Outcomes by Age Group during Late-Stage Rehabilitation (Males)

Risk of Graft Rupture After Adding a Lateral Extra-articular Procedure at the Time of ACL Reconstruction: A Retrospective Comparative Study of Elite Alpine Skiers From the French National Team

Background: Elite alpine skiing is associated with a particularly high risk of anterior cruciate ligament (ACL) injuries, including graft ruptures. Despite a considerable focus on prevention, a reduction in injury rates has not been observed since the 1980s. Purpose: To determine whether elite alpine skiers undergoing ACL reconstruction (ACLR) with a lateral extra–articular procedure (LEAP) had a lower rate of ACL graft rupture when compared with those who underwent isolated ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: Elite skiers from the French ski team who had undergone ACLR, with or without a LEAP, and had a minimum follow–up of 2 years were identified from the national ski team database. Rates of secondary ACL injury were determined via interrogation of the database, review of medical notes, and a final telemedicine interview. A multivariable analysis using the penalized Cox model was performed to explore the relationship among graft rupture, surgical procedure type, and any potential explanatory variables. Results: Among 81 ACLR procedures analyzed, 50 were isolated and 31 were combined with a LEAP, which was performed using modified Lemaire or anterolateral ligament reconstruction. Graft rupture rates were 34.0% in the isolated ACLR group and 6.5% in the ACLR + LEAP group. Multivariable analysis demonstrated that adding a LEAP was associated with a significant reduction in risk of ACL graft rupture when compared with isolated ACLR (hazard ratio [HR], 5.286 [95% CI, 1.068-26.149]; P = .0412). Age (HR, 1.114; P = .1157), sex (HR, 1.573; P = .3743), and ACL graft type (HR, 1.417; P = .5394) were not significant risk factors. Conclusion: Combined ACLR and LEAP were associated with a significant reduction in the rate of ACL graft rupture in elite alpine ski athletes. Those treated with isolated ACLR remain at extremely high risk of a second ACL injury.

Beyond Distance: A Simple Qualitative Assessment of the Single-Leg Hop Test in Return-to-Play Testing.

Limb symmetry index in the single-leg hop (SLH) test has been questioned for its low predictive value in identifying secondary anterior cruciate ligament (ACL) injury. The purpose of this study was to describe a qualitative 2-dimensional (2D) scoring system for the assessment of the SLH test and associate it with the vertical ground-reaction forces (vGRF) and sagittal plane biomechanics evaluated through gold standard 3D motion analysis. Stiff landings would be associated with low 2D scores. Descriptive laboratory study. Level 4. Thirty-four competitive football (soccer) players (age 22.8 ± 4.1 years, 16 women) were enrolled. Each athlete performed a series of SLH tests. Three-dimensional motion analysis was recorded using 10 stereophotogrammetric cameras, a force platform, and 3 high-speed cameras. The 2D qualitative assessment was performed through a scoring system based on the video-analysis of sagittal plane joint kinematics. A score of 0/2 (inadequate), 1/2 (partially adequate), or 2/2 (adequate) was attributed to the movement, based on objective measurements. The vGRF was extracted from the force platform and grouped according to the results of the 2D evaluation. Significantly higher vGRF (stiffer landing) was found for athletes obtaining a 0/2 score compared with those obtaining a 2/2 score (up to 0.8 body weight higher, P < 0.01). A significant negative rank correlation was found between the vGRF and the total score (ρ = -0.17, P = 0.03). The qualitative scoring system effectively identified stiff landings in the SLH for distance test. The qualitative scoring system could be a user-friendly standardized method to assess athletes' movement quality in return to sport clearance decision after ACL injury.

Tibiofemoral Relationship 3 Weeks After Anatomic Triple-Bundle Anterior Cruciate Ligament Reconstruction With 10 N of Initial Tension Is Closer to Normal Knee Versus That With 20 N of Initial Tension

PurposeThis study aimed to clarify the effect of initial graft tension on the ensuing tibiofemoral relationship and on 2-year clinical outcomes after anatomic triple-bundle anterior cruciate ligament (ACL) reconstruction. MethodsA total of 31 patients with primary unilateral ACL rupture (mean age, 25.1 years) were enrolled. Anatomic triple-bundle ACL reconstruction was performed using semitendinosus tendon autografts, and patients were grouped according to the total initial tension at graft fixation: 20 N for 16 patients between January 2012 and December 2012 and 10 N for 15 patients between January 2013 and December 2013. Three-dimensional computed tomography scans were performed preoperatively and at 3 weeks and 6 months postoperatively. The side-to-side difference of the 3-dimensional tibial position relative to the femur was compared at each time point. The side-to-side difference in anterior laxity was sequentially compared preoperatively, immediately after surgery, and at 6 months and 2 years postoperatively. Clinical outcomes at 2 years were likewise compared. ResultsOne patient in each group was excluded because of secondary ACL injury. At 3 weeks postoperatively, 2.5 ± 1.3 and 1.0 ± 1.3 mm of posterior tibial displacement and 3.8° ± 2.4° and 2.0° ± 1.7° of external rotation were observed in the 20- and 10-N initial tension groups, respectively, with significant differences (P = .006 and .033). At 6 months postoperatively, anterior displacement was 0.1/0.1 mm and external rotation was 0.8°/0.4° in both groups, without any significant differences. The 2-year clinical outcomes were satisfactory, including mean side-to-side difference in anterior knee laxity of 0.5 mm in both groups. ConclusionThe tibiofemoral relationship 3 weeks after anatomic triple-bundle ACL reconstruction with 10 N of initial tension is less constrained than that with 20 N. Six-month tibiofemoral relationship and 2-year clinical outcomes are satisfactory in both groups. Level of EvidenceIII, retrospective comparative trial

Reinjury Rates in Adolescent Patients 2 Years Following ACL Reconstruction

Background: Sports injuries have increased dramatically in the pediatric and adolescent population. Return-to-sport testing and criteria are increasingly utilized, however, the guidelines for return to play in adolescents are unclear. The purpose of this study was to compare strength and function at the time of the return-to-sport progression to those with and without a failed anterior cruciate ligament reconstruction (ACLR). Methods: A total of 105 adolescent patients with primary ACLR were assessed at the time of return to sport. We identified graft failures/contralateral injury through medical records, clinic visits, or phone interviews at minimum 2 years of postsurgical follow-up. All patients completed bilateral isokinetic strength tests of the knee extensor/flexor groups and hop tests. Strength was expressed as torque-normalized-to-mass (Nm/kg), and limb-symmetry-index was expressed as a percentage of the uninvolved limb’s strength. All patients completed outcome surveys. The χ2 analysis was used to compare failures between sexes and graft types. Independent sample t tests were used to compare knee extensor/flexor strength, symmetry, and hop test results between patients with and without secondary anterior cruciate ligament (ACL) injury. One-way analysis of variance was used to compare knee extensor/flexor strength and symmetry, hop test, and survey results between those (1) without secondary injury, (2) ACLR graft failure, and (3) contralateral ACL injury. Results: A total of 100 of 105 patients (95.2%) were included with 4±1.2 years of follow-up, with 28 (28%) sustaining subsequent injury (12% graft, 16% contralateral). Patients with graft failure demonstrated (1) stronger quadriceps strength (2.00±0.46 Nm/kg) compared with those with contralateral ACL injury (1.58±0.35 Nm/kg, P=0.039) and patients that did not have a secondary injury (1.58±0.44 Nm/kg, P=0.007), (2) greater quadriceps strength symmetry (85.7±0.11.2%) compared with patients without secondary injury ACL (72.9±17.9%, P=0.046), (3) a greater proportion of hamstring grafts compared with those without reinjury (P=0.028). Conclusions: Adolescent patients who sustained ACLR graft failure had greater and more symmetric quadriceps strength at the time of return to sport compared with patients with no secondary injury. Objective measures of quadriceps strength at the time of the return-to-sport progression may not solely identify individuals that have a secondary ACL injury. Study Design: Level IV—retrospective cohort study.

A 2D qualitative movement assessment of a deceleration task detects football players with high knee joint loading

PurposeThe deceleration (pressing) is a common situational pattern leading to anterior cruciate ligament (ACL) injury in football. Although mainly assessed for performance purposes, a stronger focus on movement quality might support the screening of at-risk athletes. The aim of the present study was to describe a 2D scoring system for the assessment of the deceleration task and to associate it with the knee joint loading (knee abduction moment) evaluated through the gold standard 3D motion capture. The hypothesis was that lower 2D scores would be associated with higher knee joint loading.MethodsThirty-four competitive football (soccer) players (age 22.8 ± 4.1, 16 females) performed a series of deceleration tasks. 3D motion analysis was recorded using ten stereophotogrammetric cameras, a force platform, and three high-speed cameras. The 2D qualitative assessment was performed via a scoring system based on the video analysis of frontal and lateral planes joint kinematics for five scoring criteria. The intra- and inter-rater reliabilities were calculated for each 2D scoring criteria. The peak knee abduction moment was extracted and grouped according to the results of the 2D evaluation.ResultsAn ICC > 0.94 was found for all the 2D scoring criteria, both for intra-rater and inter-rater reliability. The players with low 2D frontal plane scores and low total scores (0–4) showed significantly higher peak knee abduction moment values (p < 0.001). A significant negative rank correlation was found between the total score and the peak knee abduction moment (ρ = − 0.25, p < 0.001).ConclusionsThe qualitative 2D scoring system described successfully discerned between athletes with high and low knee joint loading during a deceleration task. The application of this qualitative movement assessment based on a detailed and accurate scoring system is suitable to identify players and patients with high knee joint loading (high knee abduction moments) and target additional training in the scenario of the primary and secondary ACL injury risk reduction.Level of evidenceLevel IV.

Predicting Anterior Cruciate Ligament Reinjury From Return-to-Activity Assessments at 6 Months Postsurgery: A Prospective Cohort Study.

Return-to-activity (RTA) assessments are commonly administered after anterior cruciate ligament reconstruction (ACLR) to manage the patient's postoperative progressions back to activity. To date, few data are available on the clinical utility of these assessments to predict patient outcomes such as secondary anterior cruciate ligament (ACL) injury once the athlete has returned to activity. To identify the measures of patient function at 6 months post-ACLR that best predict RTA and second ACL injury at a minimum of 2 years after ACLR. Prospective cohort study. Laboratory. A total of 234 patients with primary, unilateral ACLR completed functional assessments at approximately 6 months post-ACLR. Of these, 192 (82.1%) completed follow-up at ≥2 years post-ACLR. The 6-month functional assessments consisted of patient-reported outcomes, isokinetic knee-flexor and -extensor strength, and single-legged hopping. We collected RTA and secondary ACL injury data at ≥2 years after ACLR. Of the patients who were able to RTA (n = 155), 44 (28.4%) had a subsequent ACL injury, 24 (15.5%) to the ipsilateral graft ACL and 20 (12.9%) to the contralateral ACL. A greater proportion of females had a secondary injury to the contralateral ACL (15/24, 62.5%), whereas a greater proportion of males reinjured the ipsilateral ACL graft (15/20, 75.0%; P = .017). Greater knee-extension symmetry at 6 months increased the probability of reinjury (B = 0.016, P = .048). Among patients with RTA at <8 months, every 1% increase in quadriceps strength symmetry at 6 months increased the risk of reinjury by 2.1% (B = 0.021, P = .05). Among patients with RTA at >8 months, every month that RTA was delayed reduced the risk of reinjury by 28.4% (B = -0.284, P = .042). Descriptive statistics of patient function stratified between the early and delayed RTA groups can be found in the Supplemental Table (available online at http://dx.doi.org/10.4085/1062-6050-0407.20.S1). Patients with more symmetric quadriceps strength at 6 months post-ACLR were more likely to experience another ACL rupture, especially those who returned to sport at <8 months after the index surgery. Clinicians should be cognizant that returning high-functioning patients to activity at <8 months post-ACLR may place them at an increased risk for reinjury.

Anterior Cruciate Ligament Injuries in Australian Rules Football: Incidence, Prevention and Return to Play Outcomes.

Australian Rules football is the most popular of the various codes of football played in Australia. During the game players perform frequent landing, cutting and pivoting manoeuvres that expose them to substantial risk for anterior cruciate ligament (ACL) injury. Recent years have seen the introduction of a professional women’s league that has resulted in an exponential growth in the participation of women and girls in this sport. Unfortunately, there is a corresponding growth in ACL injury rates in female players. This review summarizes the incidence of ACL injury in both men’s and women’s Australian Rules football and reviews potential causative factors and risk reduction strategies. The final section takes an in depth look at return to sport outcomes after ACL reconstruction surgery in these populations. Whilst an ACL injury does not mean the end of a player’s career in Australian football, it certainly presents a significant challenge in terms of return to preinjury levels of form and high rates of secondary and tertiary ACL injury are also a significant concern.

A Secondary Injury Prevention Program May Decrease Contralateral Anterior Cruciate Ligament Injuries in Female Athletes: 2-Year Injury Rates in the ACL-SPORTS Randomized Controlled Trial.

To determine whether the addition of perturbation training to a secondary injury prevention program reduces the rate of second anterior cruciate ligament (ACL) injury compared to the prevention program alone. Single-blinded randomized controlled trial. Thirty-nine female athletes who intended to return to cutting/pivoting sports were enrolled 3 to 9 months after primary anterior cruciate ligament reconstruction (ACLR). Athletes were randomized to receive a training program of either progressive strengthening, agility, plyometrics, and prevention (SAPP) (n = 20) or SAPP plus perturbation training (n = 19); each had 10 sessions over 5 weeks. Occurrence and side of second ACL injury were recorded for 2 years after primary ACLR. There were 9 second ACL injuries in the 2 years after ACLR. There was no statistically significant difference in rate or side of second ACL injury between the SAPP-plus-perturbation training and SAPP groups. Adding perturbation training to a secondary ACL injury prevention program did not affect the rate of second ACL injury in female athletes. J Orthop Sports Phys Ther 2020;50(9):523-530. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9407.

Decision Tree Learning Algorithm for Classifying Knee Injury Status Using Return-to-Activity Criteria.

Anterior cruciate ligament (ACL) injury rates in female adolescents are increasing. Irrespective of treatment options, approximately 1/3 will suffer secondary ACL injuries following their return to activity (RTA). Despite this, there are no evidence-informed RTA guidelines to aid clinicians in deciding when this should occur. The first step towards these guidelines is to identify relevant and feasible measures to assess the functional status of these patients. The purpose of this study was therefore to evaluate tests frequently used to assess functional capacity following surgery using a Reduced Error Pruning Tree (REPT). Thirty-six healthy and forty-two ACLinjured adolescent females performed a series of functional tasks. Motion analysis along with spatiotemporal measures were used to extract thirty clinically relevant variables. The REPT reduced these variables down to two limb symmetry measures (maximum anterior hop and maximum lateral hop), capable of classifying injury status between the healthy and ACL injured participants with a 69% sensitivity, 78% specificity and kappa statistic of 0.464. We, therefore, conclude that the REPT model was able to evaluate functional capacity as it relates to injury status in adolescent females. We also recommend considering these variables when developing RTA assessments and guidelines.Clinical Relevance- Our results indicate that spatiotemporal measures may differentiate ACL-injured and healthy female adolescents with moderate confidence using a REPT. The identified tests may reasonably be added to the clinical evaluation process when evaluating functional capacity and readiness to return to activity.

ANALYSIS OF TIMING OF SECONDARY ACL INJURY IN PROFESSIONAL ATHLETES DOES NOT SUPPORT GAME TIMING OR SEASON TIMING AS A CONTRIBUTOR TO INJURY RISK

Anterior cruciate ligament (ACL) injuries are a common cause of time loss in sports. Approximately one-third of ACL reconstructed athletes who return to sport suffer secondary injury. The presence of fatigue during athletic performance has been hypothesized to increase susceptibility to ACL injury. However, the relative role of fatigue in secondary ACL failures remains unexplored. To assess how time elapsed within a game and within a season associate with secondary ACL injury occurrence in international professional athletes and American collegiate athletes. Retrospective cohort analysis. The public domain was searched for secondary ACL injuries that occurred during competitive matches between 2000-2018. Demographics (age, height, weight), side of injury, type of injury (contact, noncontact), and timing of injury within competition and within season were determined for each case. Sixty-seven secondary ACL injuries were identified. Within-game, there were no differences in the distribution of ACL injures across each quarter of game time (p = 0.284). This was consistent between sport (p = 0.120-0.448). Within-season, there were no differences in the distribution of secondary ACL injures across each quarter of the season (p = 0.491). This was again consistent between sport (p = 0.151-0.872). Relative risk was not found to be significantly greater for any combination of season and game. The results of the current study indicate that the occurrences of secondary ACL injuries were equally distributed with respect to in-game and in-season timing. Both in-game and in-season timing were not significantly different across each individual sport examined. These results implicate that overall there is not an association between fatigue and secondary ACL injury occurrence in professional athletes. 3.

Recent Advances in Prevention of Primary and Secondary Anterior Cruciate Ligament Injury: What Does the Future Hold for Optimizing Knee-Joint Function?

Despite considerable advances in anterior cruciate ligament (ACL) injury-risk identification and prevention over the past 20 years, the annual incidence of ACL injury has continued to rise, and females remain at greater risk of both primary and secondary ACL injury. Important questions remain regarding ancillary risk factors we should target, the most effective training and rehabilitation approaches to ensure retention and transfer of learned skills from the rehabilitation setting to real-world sporting environment, and the development of more evidence-based criteria for return to sport that consider the whole athlete. As we look to the future, the optimization of primary and secondary ACL-injury prevention represents a complex, multidisciplinary problem with many unique and exciting opportunities to engage the various subdisciplines of kinesiology to address these emerging questions.

Combined Transphyseal and Lateral Extra-articular Pediatric Anterior Cruciate Ligament Reconstruction: A Novel Technique to Reduce ACL Reinjury While Allowing for Growth

Background: Treatment of anterior cruciate ligament (ACL) injuries in the adolescent population continues to be complicated by an unacceptably high rate of secondary ACL injury. Purpose: To describe the failure rate and outcomes after a hybrid pediatric ACL reconstruction (ACLR) employing transphyseal hamstring (TPH) autograft combined with an extra-articular technique using an iliotibial band (ITB) autograft. Study Design: Case series; Level of evidence, 4. Methods: Consecutive patients undergoing combined TPH-ITB ACLR between January 2012 and April 2017 with a minimum 2-year follow-up were reviewed. With the goal of decreasing ACL graft injury in this high-risk group, this technique employed anteromedial portal drilling for TPH with an extraosseous femoral ITB technique and intra-articular TPH-ITB grafts fixed within the tibial bone tunnel. Demographics, bone age, standing alignment radiograph for growth and mechanical axis grade, return to sport, graft failure, and patient-reported outcome measures were analyzed. Results: A total of 61 knees in 60 adolescents underwent the combined TPH-ITB ACLR, with 57 knees (93.4%) meeting inclusion criteria with a mean follow-up of 38.5 months (range, 24-78 months). Only 3 of 57 knees (5.3%) sustained ACL reinjury. The mean age was 13.0 years (range, 11-16 years) with 36 male patients (mean bone age, 14.2 years) and 21 female patients (mean bone age, 13.3 years), and 91% of patients (52 of 57) returned to sport. Participants demonstrated a high functional level at final follow-up, with a mean score of 91.2 (range, 46.7-100) on the Pediatric International Knee Documentation Committee (Pedi-IKDC) Subjective Knee Evaluation Form and mean score of 22.4 (range, 4-30) on the Pediatric Functional Activity Brief Scale (Pedi-FABS). To critically assess growth, a cohort with ≥18 months of growth remaining at surgery was evaluated at maturity. No difference was seen in mean operative and nonoperative leg growth (49.7 mm and 49.8 mm). Although no family reported cosmetic or functional alignment or length concerns, 1 of 18 (5.5%) had a final limb length discrepancy >10 mm (12 mm) and a perioperative alignment difference (0-Grade II valgus). Conclusion: Combined TPH-ITB ACLR in adolescents resulted in high activity levels (Pedi-FABS, 22.4; median, 25) and a low (5.3%) graft failure rate at a mean 38.5 months.

Risk of Secondary ACL Injury in Adolescents Prescribed Functional Bracing After ACL Reconstruction.

Background:There is a high incidence of a secondary anterior cruciate ligament (ACL) injury in unbraced adolescent athletes. Little is known about the effect of functional bracing with regard to the risk of secondary ACL injuries among adolescents.Hypothesis:Our primary hypothesis was that adolescents would have a high rate of secondary ACL injury even with brace use. A secondary hypothesis was that the reinjury rate with brace use would be lower than that of a historical control group of unbraced patients.Study Design:Case series; Level of evidence, 4.Methods:A group of 219 patients (age <20 years at surgery) who underwent ACL reconstruction and were prescribed postoperative functional bracing during cutting and pivoting sports for 2 years after surgery completed a survey regarding reinjury to either knee. Rates of knee injuries following ACL reconstruction were calculated and compared with those reported in a similar unbraced cohort. The effect of demographic and anatomic factors on risk of secondary ACL injuries was also investigated.Results:The overall follow-up rate was 65% (142/219) at a mean 5.6 years after surgery. In the braced cohort, the overall graft retear rate was 10%, with the highest retear rates observed in male patients 17 years of age and younger (18%). The overall contralateral ACL injury and combined (graft or contralateral ACL) secondary injury rates were 13% and 23%, respectively, with female patients younger than 18 years having the highest contralateral and combined injury rates (17% and 26%, respectively). Younger age (odds ratio [OR], 0.70; P = .021), family history of ACL injury (OR, 2.81; P = .015), and higher lateral tibial slope (OR, 1.25; P = .016) were associated with increased risk of secondary knee injury in the braced cohort. Compared with the unbraced cohort, the braced cohort had a lower overall graft retear rate (P = .028), a lower graft retear rate in patients younger than 18 years (P = .012), lower early graft retear rate (within the first year after surgery) (P = .011), and lower early graft retear rate in subjects younger than 18 years (P = .003).Conclusion:Postoperative use of functional bracing can result in reduced risk of graft retear and no change in contralateral injury rates. Clinicians may want to consider the use of postoperative functional bracing in adolescent patients.