Anterior Cruciate Ligament Injury Rates Research Articles

INCORPORATING WORKLOAD MEASURES INTO REHABILITATION AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A CASE REPORT.

and purpose: Second anterior cruciate ligament (ACL) injury rates continue to be high, with a majority of injuries occurring soon after return-to-play, potentially because athletes may not be ready for the external load demands of the sport. Load metrics, tracked through wearable technology, may provide complementary information to standard limb symmetry indices in the return-to-play decision making process. The purpose of this case report was to quantify and monitor load using innovative technology during physical therapy rehabilitation after ACL reconstruction (ACLr) and compare to normative sport participation data.Case Description: The subject was a 12-year-old female soccer player that suffered an ACL injury followed by surgical reconstruction with a hamstring autograft and standard rehabilitation. Single-leg hop performance, isokinetic strength, and external loads (using wearable technology) were measured longitudinally during rehabilitation and analyzed at the time of return-to-play.Outcomes: The subject successfully achieved >90% LSI for isometric quadriceps strength (week 14), single leg hop battery (week 23), and isokinetic hamstrings (week 26) and quadriceps (week 31) strength by the time of return-to-play (week 39). At the time of return to play, external load metrics indicated that the subject's most intense rehabilitation session consisted of 36% less frequent movements, 38% lower total distances, and activity durations that were 29% lower than the expected demands of a match. Standard rehabilitation may underload patients relative to required sport demands. Measuring external load during the rehabilitation period may help clinicians adequately progress workload to the necessary demands of the patient's sport. With the current emphasis on restoring limb symmetry, clinicians may need to shift focus towards load preparation when returning a patient to their sport.Level of Evidence: 4Keywords: anterior cruciate ligament, load, rehabilitation, return to play, step count, movement system.

Do Pediatric Patients With Anterior Cruciate Ligament Tears Have a Higher Rate of Familial Anterior Cruciate Ligament Injury?

Background:Several studies have examined the anterior cruciate ligament (ACL) injury history among relatives of patients undergoing ACL reconstruction (ACLR), but they have primarily analyzed adults with variable results.Hypothesis:We hypothesized that he rate of familial ACL injuries among pediatric patients with ACL tears would be greater than that among pediatric patients with uninjured knees.Study Design:Cohort study; Level of evidence, 3.Methods:Pediatric patients (≤18 years of age) who underwent ACLR between January 2009 and May 2016 were contacted to complete a questionnaire on subsequent complications and family history of ACL tears. A control cohort was recruited from children with uninjured knees seen in the concussion clinic of our institution. Binary logistic regression was used to determine the factors predictive of having a familial ACL tear history or complications.Results:Overall, 450 pediatric patients with primary ACL tears were included. Age at the time of surgery was 14.9 ± 2.2 years with a follow-up of 4.3 ± 2.1 years. When compared with 267 control patients, those with an ACL tear reported a higher rate of first-degree relatives with an ACL injury history (25.1% vs 12.0%; P < .001). In multivariate analysis, children with ACL injury had nearly 3 times (odds ratio [OR], 2.7) higher odds of having a first-degree relative with an ACL tear (95% CI, 1.7-4.2; P < .001). Patients were stratified by the number of first-degree relatives with ACL tears: no relatives, 1 relative, or ≥2 relatives. Children with ≥2 first-degree relatives were more likely to sustain a postoperative graft failure (OR, 5.1; 95% CI 1.7-15.2; P = .003) or a complication requiring surgical intervention (OR, 7.5; 95% CI, 2.6-22.0; P < .001).Conclusion:A family history of ACL injury is more likely in pediatric patients with ACL tears than in uninjured children. Further, patients undergoing primary ACLR as well as a strong family history of ACL tears are more likely to sustain a postoperative graft rupture or complication requiring surgery.

Perceived barriers to implementation of injury prevention programs among collegiate women’s soccer coaches

ObjectivesKnee injury prevention programs (IPPs) reduce knee and anterior cruciate ligament (ACL) injury rates in female athletes, however, implementation of IPPs is low. The purpose of this study was to identify barriers to implementation of IPPs among collegiate women’s soccer coaches. DesignCross-sectional survey. MethodsA custom survey based on the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework and existing literature was sent to 151 out of 153 women’s National Collegiate Athletic Association (NCAA) soccer coaches in the NCAA’s Eastern Region. ResultsTen respondents reported that they did not use an IPP (Non-users), and nineteen respondents reported that they did use an IPP (Users). “Cost” was the most highly ranked barrier (median rank: 2) to implementing an IPP among Non-users. For the statement, “Who should be responsible for completing an IPP,” Users said “Coaches” (47%) and “Other” (21%), while Non-users said “Strength and conditioning” (50%) and “Athletic trainers” (30%). Respondents who marked “Other”, elaborated that it was the responsibility of coaches, athletes, and additional staff members. ConclusionsCost was the primary barrier to implementation of an IPP. Since the majority of Non-users indicated that implementation of an IPP was the responsibility of a non-coaching staff member, cost may be a surrogate for the expense of hiring an additional staff member rather than the cost of performing the IPP itself. Additionally, using a team-based approach that encompasses athletes, coaches, and non-coaching staff members may support long-term implementation of IPPs.

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.

Hamstring autograft versus patellar tendon autograft for anterior cruciate ligament reconstruction, which graft has a higher contralateral anterior cruciate ligament injury rate?: A meta-analysis of 5561 patients following the PRISMA guidelines.

Background:Contralateral anterior cruciate ligament (CACL) injury is one of the devastating complications after anterior cruciate ligament (ACL) reconstruction. Whether the risk of CACL tear is related to graft selection remains controversial due to contradictory results in studies. There are no meta-analyses to compare which graft has a higher CACL injury rate. Hence, this meta-analysis was conducted to compare the incidence of the CACL injury after ACL reconstruction with bone-patellar tendon-bone (BPTB) autografts compared with hamstring (HT) autografts.Methods:A comprehensive search of literature published between 1980 and January 2020 was performed using MEDLINE, EMBASE, Web of Science, and the Cochrane Library databases. RevMan 5.3 software was used for meta-analysis. The overall risk ratio (RR) was calculated using a fixed- or random-effects. The heterogeneity among the included results was analyzed by chi-square test with significance set at P < .10, and the heterogeneity was quantitatively detected by I-square tests.Results:Fifteen prospective comparative studies met inclusion criteria. In the BPTB group, the CACL rupture rate ranged from 1.8% to 30%, with a pooled percentage of 8.5%. In the HT group, the CACL rupture rate ranged from 0% to 14.4%, with a pooled percentage of 3.3%. The overall CACL rupture rate was 3.1% and ranged from 1.1% to 27.1%, with a pooled percentage of 4.9%. The pooled results indicate that there was a statistical significant difference in CACL rupture risk rate between BPTB and HT autograft. (RR, 1.53; 95% CL, 1.21–1.91; P = .0004).Conclusion:This review showed that patients undergoing primary ACL reconstruction with BPTB autograft were more likely to have CACL rupture than patients treated with HT autograft.

Higher risk of contralateral anterior cruciate ligament (ACL) injury within 2years after ACL reconstruction in under-18-year-old patients with steep tibial plateau slope.

To assess the role of Tibial Plateau Slope (TPS) as risk factor for early Anterior Cruciate Ligament (ACL) reconstruction failure and contralateral ACL injury in a population of patients with less than 18years of age and operated on with the same surgical technique. Ninety-four consecutive patients (mean age 15.7 ± 1.5years) with at least 2years of follow-up, who underwent ACL reconstruction with a single-bundle plus lateral-plasty hamstring technique in the same centre were included. Subsequent ACL injuries (ipsilateral ACL revision or contralateral ACL reconstruction) were assessed within the first 2years after surgery. Anterior, central, posterior TPS of medial compartment were measured on lateral radiographs and compared between patients with intact graft and those with a second injury. Cut-off values with sensitivity and specificity were calculated with receiver operating characteristic (ROC) analysis. Survival analysis for second ACL injuries and multivariate analysis were performed. Eight patients (9%) had ipsilateral ACL Revision and eight patients (9%) had contralateral ACL reconstruction. Patients with contralateral injury had a higher Central TPS with respect to those without second injury (12.6° ± 2.8° vs 9.3° ± 3.7°, p = 0.042). No differences were present in patients with ipsilateral ACL revision. Sensitivity and specificity for central TPS slope ≥ 12° to detect a contralateral rupture were 63% and 75% (p = 0.0092), for Anterior TPS were 100% and 52% (p = 0.0009). Patients with TPS values exceeding these cut-offs had higher rate of contralateral ACL injuries (19%vs4%, p = 0.0420) and lower 2-year survival (p = 0.0049). Multivariate analysis identified pre-operative sport level and TPS (either anterior or central) as risk factors for contralateral injuries. Steep tibial plateau slope ≥ 12° is associated with a higher risk of contralateral ACL injury within 2years after ACL reconstruction in patients less than 18years of age. However, TPS has no role in early ipsilateral re-injury after combined ACL reconstruction and lateral plasty. The clinical relevance is that both the surgeon and the patient should be aware of this higher risk and consider it in the rehabilitation phase to reduce the incidence of such injuries. III.

Epidemiology of Anterior Cruciate Ligament Injury on Natural Grass Versus Artificial Turf in Soccer: 10-Year Data From the National Collegiate Athletic Association Injury Surveillance System.

Background:Anterior cruciate ligament (ACL) injury is prevalent among National Collegiate Athletic Association (NCAA) soccer players. Controversy remains regarding the effect of the surface type on the rate of ACL injury in soccer players, considering differences in sex, type of athletic exposure, and level of competition.Hypothesis:Natural grass surfaces would be associated with decreased ACL injury rate in NCAA soccer players. Sex, type of athletic exposure (match vs practice), and level of competition (Division I-III) would affect the relationship between playing surface and ACL injury rates.Study Design:Cohort study; Level of evidence, 3.Methods:Using the NCAA Injury Surveillance System (ISS) database, we calculated the incidence rate of ACL injury in men and women from 2004-2005 through 2013-2014 seasons. The incidence was normalized against athletic exposure (AE). Additional data collected were sex, athletic activity at time of injury (match vs practice), and level of competition (NCAA division) to stratify the analysis. Statistical comparisons were made by calculating incidence rate ratios (IRR). Statistical significance was set at an alpha of .05.Results:There were 30,831,779 weighted AEs during the study period. The overall injury rate was 1.12 ACL injuries per 10,000 AEs (95% CI, 1.08-1.16). Women comprised 57% of the match data (10,261 games) and 55% of practice data (26,664 practices). The overall injury rate was significantly higher on natural grass (1.16/10,000 AEs; 95% CI, 1.12-1.20) compared with artificial turf (0.92/10,000 AEs [95% CI, 0.84-1.01]; IRR, 1.26 [95% CI, 1.14-1.38]) (P < .0001). This relationship was demonstrated consistently across all subanalyses, including stratification by NCAA division and sex. The injury rate on natural grass (0.52/10,000 AEs; 95% CI, 1.11-1.26) was significantly greater than the injury incidence during practice on artificial turf (0.06/10,000 AEs; 95% CI, 0.043-0.096). Players were 8.67 times more likely to sustain an ACL injury during practice on natural grass compared with practice on artificial turf (95% CI, 5.43-12.13; P < .0001). No significant difference was found in injury rates between matches played on grass versus turf (IRR, 0.93; 95% CI, 0.84-1.03; P = .15).Conclusion:NCAA soccer players who practice on natural grass have increased risk of ACL injury compared with the risk of those practicing on an artificial surface, regardless of sex or NCAA division of play. No difference in risk of ACL injury between playing surfaces was detected during matches. Further research is necessary to examine the effect of multiple factors when evaluating the effect of the surface type on the risk of ACL injury in soccer players.

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.

Sex-Based Differences in Anterior Cruciate Ligament Injuries Among United States High School Soccer Players: An Epidemiological Study.

Background:Anterior cruciate ligament (ACL) tears are common among high school athletes, with sex-based differences accounting for higher injury rates in girls. Previous epidemiological studies on ACL injuries focusing on adolescent athletes have looked at injuries across multiple sports, but few have analyzed ACL tears in solely high school soccer athletes.Purpose:To examine sex-based differences in the epidemiology of ACL injuries among high school soccer players in the United States (US).Study Design:Descriptive epidemiological study.Methods:ACL injury data for US high school soccer players were obtained from the internet-based National High School Sports-Related Injury Surveillance Study’s High School RIO (Reporting Information Online) system. Athletic trainers from a random sample of 100 high schools from 8 strata based on US Census geographic region reported data for athlete-exposures (AEs) (practice or competition) and ACL injuries from 2007 through 2017. Injury rates were calculated as the number of ACL injuries per 100,000 AEs. Subgroup differences were evaluated with rate ratios (RRs) or injury proportion ratios (IPRs) and 95% CIs. Statistical differences in demographics between groups were examined using independent t tests. Comparisons of categorical data (ie, level of play) were performed using the Wald chi-square test.Results:The reported number of ACL injuries corresponded to weighted national estimates of 41,025 (95% CI, 33,321-48,730) ACL injuries in boys’ soccer and 110,028 (95% CI, 95,349-124,709) in girls’ soccer during the study period. The rate of injuries was higher in girls’ soccer (13.23/100,000 AEs) than boys’ soccer (4.35/100,000 AEs) (RR, 3.04 [95% CI, 2.35-3.98]). The rate of ACL injuries was higher in competition compared with practice for girls (RR, 14.77 [95% CI, 9.85-22.15]) and boys (RR, 8.69 [95% CI, 5.01-15.08]). Overall, a smaller proportion of ACL injuries were caused by player-player contact for girls (30.1%) compared with boys (48.6%) (IPR, 0.62 [95% CI, 0.41-0.93]).Conclusion:ACL injury rates and patterns in high school soccer players differed between sex, type of exposure (practice vs competition), and mechanism of injury.

Do Looks or Measurements Really Matter When It Comes to ACL Tears?: Commentary on an article by Steve Bayer, BA, et al.: "Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury. A Systematic Review".

Do Looks or Measurements Really Matter When It Comes to ACL Tears?: Commentary on an article by Steve Bayer, BA, et al.: "Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury. A Systematic Review".

PROSPECTIVE MEASURES OF INTRA-REGION BRAIN REGULARITY DIFFERENTIATES ACL INJURED AND UNINJURED ATHLETES

Background:Anterior cruciate ligament (ACL) injuries are debilitating for athletes. While numerous motor and biomechanical deficits contribute to the inciting ACL injury mechanism, the limited knowledge about the underlying neural drivers of these deficits has impeded intervention development to reduce ACL injury rates. A prospective investigation using functional magnetic resonance imaging (fMRI) in female soccer players revealed decreased connectivity between the primary somatosensory cortex and cerebellum for athletes that went on to ACL injury athletes compared to their healthy teammates. Although information about inter-region connectivity patterns is informative, this finding does elucidate the individual, intra-region brain activity that may be further underlie ACL injury mechanisms.Hypothesis/Purpose:The purpose of this study was to prospectively investigate the intra-region regularity of the blood oxygen-level dependent (BOLD) signal activity in 25 knee-related regions of interests (ROI) between athletes who sustained an ACL injury and matched controls.Methods:Adolescent female soccer athletes were evaluated using fMRI to capture resting-state brain connectivity prior to their competitive season. Two of these athletes (16.0±0yrs, 169.0±2.8cm, 60.1±8.3kg) later experienced an ACL injury and were matched to eight uninjured teammates (15.9±0.8yrs, 164.0±4.9cm, 58.3±7.6kg). Standard fMRI data processing was used to determine resting-state BOLD signal activity in 25 knee-related ROIs. Sample entropy (SampEn) was then used to quantify the regularity of each individual ROI. A lower SampEn value indicates a ROI’s BOLD signal activity was more regular (predictable) and a higher value indicates a signal’s activity was more irregular (unpredictable). T-tests—with a Bonferroni correction for the familywise error rate (p < .002)—were used to compare SampEn values between both groups for all 25 ROIs.Results:ACL injured athletes (M = 0.35±0.01) exhibited higher SampEn values in the left primary motor cortex than matched, uninjured athletes (M = 0.29±0.02; t(8)=4.62, p=.0017, d=3.65).Conclusion:Athletes who sustained an ACL injury exhibited less regularity in BOLD signal activity of the left primary motor cortex. As the primary motor cortex serves as the final destination in the brain before efferent information is sent to the spinal cord to initiate movement, decreased BOLD signal regularity in this region may alter such cortical-spinal transmission. Considering ACL injuries often occur during unpredictable environments, irregular activity of motor cortex activity may dampen an athlete’s ability to sustain a safe knee position. These findings may help to guide development of brain-driven biofeedback training to promote adaptive neuroplasticity that ‘pushes’ the motor cortex towards more regular activity.Figure 1.Shown above is the location of the left primary motor cortex (indicated by the black circle to the left). In Panel A, a BOLD signal from an athlete who went on to injure her ACL is presented. In Panel B, a BOLD signal from an athlete who did not injure her ACL is shown.

Activity and functional readiness, not age, are the critical factors for second anterior cruciate ligament injury — the Delaware-Oslo ACL cohort study

ObjectiveTo elucidate the relationships between age, return to level I sport (RTS) within the first postoperative year, passing RTS criteria and second anterior cruciate ligament (ACL) injury.MethodsIn a prospective cohort...

Factors Influencing Return to Play and Second Anterior Cruciate Ligament Injury Rates in Level 1 Athletes After Primary Anterior Cruciate Ligament Reconstruction: 2-Year Follow-up on 1432 Reconstructions at a Single Center

Background: Despite the importance of return-to-play (RTP) rates, second anterior cruciate ligament (ACL) injury rates, and patient-reported outcomes of athletes returning to sports after ACL reconstruction (ACLR), these outcomes have not been evaluated together across a single cohort nor the pre- and intraoperative factors influencing outcomes explored. Purpose: To prospectively report outcomes after ACLR relating to RTP, second ACL injury, and International Knee Document Committee (IKDC) scores in a large cohort of athletes at a single center to examine the influence of pre- and intraoperative variables on these outcomes. Design: Cohort study; Level of evidence, 3. Methods: A consecutive cohort of 1432 athletes undergoing primary ACLR by 2 orthopaedic surgeons was followed up prospectively more than 2 years after surgery. Pre- and intraoperative findings were reported with outcomes at follow-up relating to RTP, second ACL injury, and IKDC. Between-group differences for each outcome were reported and the predictive ability of pre- and intraoperative variables relating to each outcome assessed with logistic regression. Results: There was >95% follow-up 2 years after surgery. The RTP rate was 81%, and of those who returned, 1.3% of those with patellar tendon grafts and 8.3% of those with hamstring grafts experienced ipsilateral rerupture (hazard ratio, 0.17). The contralateral ACL injury rate was 6.6%, and the IKDC score at follow-up was 86.8, with a greater proportion of patients with patellar tendon grafts scoring <80 on the IKDC (odds ratio, 1.56; 95% CI, 1.15-3.12). There was no relationship between time to RTP and second ACL injury, and there was a moderate correlation between ACL–Return to Sport After Injury score and RTP at follow-up (P < .001, rho = 0.46). There were a number of differences in pre- and intraoperative variables between groups for each outcome, but they demonstrated a poor ability to predict outcomes in level 1 athletes at 2-year follow-up. Conclusion: Findings demonstrated high overall RTP rates, lower reinjury rates with patellar tendon graft after 2-year follow-up in level 1 athletes, and no influence of time to RTP on second ACL injury. Despite differences between groups, there was poor predictive ability of pre- and intraoperative variables. Results suggest pre- and intraoperative variables for consideration to optimize outcomes in level 1 athletes after ACLR, but future research exploring other factors, such as physical and psychological recovery, may be needed to improve outcome prediction after ACLR. Registration: NCT02771548 (ClinicalTrials.gov identifier).

Young Athletes Who Return to Sport Before 9 Months After Anterior Cruciate Ligament Reconstruction Have a Rate of New Injury 7 Times That of Those Who Delay Return

To investigate the association between sustaining a second anterior cruciate ligament (ACL) injury and (1) time to return to sport, (2) symmetrical muscle function, and (3) symmetrical quadriceps strength at the time of return to sport in young athletes after primary ACL reconstruction. Prospective cohort study. Patient demographics and results from 5 tests of muscle function (2 strength tests and 3 hop tests) were extracted from a rehabilitation registry. A questionnaire was sent to athletes (15-30 years old) who were involved in knee-strenuous sport before the injury and had undergone primary ACL reconstruction to determine time of return to knee-strenuous sport (preinjury Tegner Activity Scale score of 6 or greater). We used the Cox proportional hazard regression model to analyze time to event. One hundred fifty-nine (32% of the initial sample) athletes (mean ± SD age, 21.5 ± 4.4 years; 64% female) were included. Athletes with a higher preinjury Tegner Activity Scale score had a higher rate of second ACL injury (hazard ratio = 2.1; 95% confidence interval: 1.2, 3.6; P<.01). Athletes who returned to knee-strenuous sport before 9 months after reconstruction had a higher rate of second ACL injury (hazard ratio = 6.7; 95% confidence interval: 2.6, 16.7; P<.001). There was no association between symmetrical muscle function or quadriceps strength and second ACL injury. Returning to knee-strenuous sport before 9 months after ACL reconstruction was associated with an approximately 7-fold increased rate of sustaining a second ACL injury. Achieving symmetrical muscle function or quadriceps strength was not associated with new ACL injury in young athletes. J Orthop Sports Phys Ther 2020;50(2):83-90. doi:10.2519/jospt.2020.9071.

More Than a 2-Fold Risk of Contralateral Anterior Cruciate Ligament Injuries Compared With Ipsilateral Graft Failure 10 Years After Primary Reconstruction

Background: Failure of anterior cruciate ligament (ACL) reconstruction or an injury to the ACL in the contralateral knee represents a devastating event for patients, especially those young and physically active. However, controversies are still present regarding long-term failure rates and risk factors. Purpose: To assess the long-term rate of ipsilateral graft failure and contralateral ACL injuries after ACL reconstruction performed at a single center using the same surgical technique with a hamstring autograft and to investigate the effect of sex, age, and preinjury activity level as predictors of second ACL injuries. Study Design: Case series; Level of evidence, 4. Methods: The study cohort consisted of 244 consecutive patients (mean age, 30.7 years) who underwent ACL reconstruction with a single bundle plus lateral plasty technique using the hamstring tendon between November 2007 and May 2009. The number of subsequent ACL injuries (ipsilateral ACL revision or contralateral ACL reconstruction) was determined at a minimum follow-up of 10 years. Survivorship of either knee and subgroup analysis included sex, age, preoperative Tegner activity level, timing of ACL reconstruction, body mass index, and smoking status. Results: Ipsilateral ACL revision was performed in 8 (3.4%) patients and contralateral ACL reconstruction in 19 (7.8%) patients. Only 1 patient had both ipsilateral and contralateral injuries. No predictors were found for ipsilateral ACL revision, while age <18 years and preoperative Tegner level ≥7 had a higher risk of contralateral ACL reconstruction. The highest rate of a second ACL reconstruction procedure was in young (<18 years) and active (Tegner ≥7) patients, in whom the 10-year survival of either knee was 61.1%. Six years after primary ACL reconstruction, the rate of contralateral ACL reconstruction was significantly higher than that of ipsilateral ACL revision (hazard ratio, 2.4-3.6). Conclusion: In the long term, a second injury to either the ipsilateral or the contralateral knee in young and active populations could reach 40%, with a more than double-fold risk of contralateral ACL reconstruction compared with ipsilateral ACL revision.

Posterior Medial Meniscus Root Tears Potentiate the Effect of Increased Tibial Slope on Anterior Cruciate Ligament Graft Forces

Background: Increased posterior tibial slope and posterior medial meniscus root tears increase the force experienced by the anterior cruciate ligament (ACL) and predispose patients to higher rates of primary ACL injury or ACL graft failure after an ACL reconstruction (ACLR). However, the interplay among sagittal plane tibial slope, medial meniscus root tears, and ACLR graft force remains inadequately defined. Purpose/Hypothesis: The purpose was to quantify the effect of sagittal plane tibial slope on ACLR graft force at varying knee flexion angles with an intact medial meniscus, a posterior medial meniscus root tear, and a medial meniscus root repair. Our null hypothesis was that changes in slope and meniscal state would have no effect on the forces experienced by the ACLR graft. Study Design: Controlled laboratory study. Methods: Ten male fresh-frozen cadaveric human knees underwent a posteriorly based high tibial osteotomy. A spanning external fixator and wedges of varying sizes were used to stabilize the osteotomy and allow for accurate slope adjustment. After ACLR, specimens were compressed with a 1000-N axial load at flexion angles of 0° and 30° for each of the 3 meniscal states and at tibial slopes of 0° to 15° at 3° increments. Graft loads were recorded through a force transducer clamped to the graft. Results: Increasing tibial slope led to a linear increase in ACLR graft force at 0° and 30° of knee flexion. Posterior medial meniscus root tear led to significant increases in ACLR graft forces over the intact state, while root repair restored the function of the medial meniscus as a secondary stabilizer. At 30° of knee flexion, the tibial slope effect on ACLR graft force was potentiated in the root tear state as compared with the intact and root repair states—test of interaction effect: t(139) = 2.67 (P = .009). Conclusion: Increases in tibial slope lead to a linear increase in ACLR graft forces, and this effect is magnified in the setting of a posterior medial meniscus root tear. At slopes >12°, a slope-changing osteotomy could be considered in the setting of a revision ACLR with a concomitant medial meniscus root tear. Clinical Relevance: Defining the relationship between tibial slope and varying states of meniscal insufficiency can help determine when it may be necessary to perform a slope-decreasing proximal tibial osteotomy before ACLR and meniscal repair.

Epidemiology of Anterior Cruciate Ligament Injury in Italian First Division Soccer Players.

The burden of anterior cruciate ligament (ACL) injury in professional soccer players is particularly relevant as it represents a potentially career-threatening injury. Our hypotheses were that (1) injury incidence rate would be similar to that reported in the literature, (2) we would identify a uniform distribution of the injuries along the season, and (3) injury incidence rate would be similar in high-ranked and lower ranked teams, based on final placement in the league. Descriptive epidemiological study. Level 4. Professional male soccer players participating in the Serie A championship league in 7 consecutive seasons (2011-2012 to 2017-2018) were screened to identify ACL injuries through the online football archive transfermarkt.com . Exposure in matches and training were calculated. There were 84 ACL injuries found (mean player age, 25.3 ± 4.2 years). Overall, 25% of ACL injuries were reruptures (15%) or contralateral injuries (10%). ACL incidence rate was 0.4215 per 1000 hours of play during Serie A matches, 0.0305 per 1000 hours of training (rate ratio [RR], 13.8; 95% CI, 8.4-22.7; P < 0.0001), and 0.0618 per 1000 hours of total play. Injury distribution had a bimodal peak, with the highest number of events in October and March. Alternatively, training injuries peaked in June and July. A significantly higher incidence rate was found for the teams ranked from 1st to 4th place compared with those ranked 5th to 20th (0.1256 vs 0.0559 per 1000 hours of play; RR, 2.2; 95% CI, 1.4-3.6; P = 0.0003). A similar finding was found for injury incidence proportion (3.76% vs 1.64%; P = 0.0003). The overall incidence rate of ACL injuries in Italian Serie A was 0.062 per 1000 hours, with a 14-fold risk in matches compared with training. Relevantly, 25% were second injuries. Most injuries occurred in October and March, and an almost 2-fold incidence rate and incidence proportion were noted in those teams ranked in the first 4 positions of the championship league. Knowing the precise epidemiology of ACL injury in one of the most competitive professional football championship leagues could help delineate fields of research aimed to investigate its risk factors.

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.

Anterior Cruciate Ligament Injury Risk by Season Period and Competition Segment: An Analysis of National Collegiate Athletic Association Injury Surveillance Data.

Although fatigue has been implicated in anterior cruciate ligament (ACL) injury, few researchers have examined the timing of injury across a competitive sport season or within a competitive session to gain insight into the potential effects of fatigue on the incidence of ACL injury. To identify the time segments across a competitive season or within an individual competition associated with the greatest ACL injury incidence. Descriptive epidemiology study. Data from the National Collegiate Athletic Association Injury Surveillance Program for 2004-2005 through 2015-2016 for basketball, lacrosse, and soccer were analyzed. Incidence rate ratios (IRRs) compared ACL injury rates by sport, sex, season segment, and competition period. Poisson regression was used to examine the associations between each of these categories and the incidence of ACL injury as well as interaction effects. During the early regular season, the incidence rate was elevated relative to the preseason (IRR = 1.86; 95% confidence interval [CI] = 1.27, 2.74), middle regular season (IRR = 1.48; 95% CI = 1.01, 2.15), late regular season (IRR = 1.56; 95% CI = 1.08, 2.27), and postseason (IRR = 2.20; 95% CI = 1.06, 4.56). A sport-by-season interaction indicated this effect was largely attributable to a higher incidence in the early season among lacrosse athletes. An interaction between season segment and competition period (P = .02) revealed a greater injury incidence before halftime in the early regular season (IRR = 0.38, 95% CI = 0.19, 0.76), but a greater incidence after halftime in the late regular season (IRR = 2.40, 95% CI = 1.15, 5.02). Fewer noncontact injuries occurred in soccer than in basketball or lacrosse. The ACL injury incidence was higher in the early part of the regular season, particularly among lacrosse athletes. Although the injury incidences before and after halftime were similar, further analyses of player time and time of injury within each half are necessary. Coaches and practitioners should be cognizant of the elevated injury incidence during the early season among lacrosse athletes. Future authors should consider more specific analyses to further elucidate the potential role of fatigue development in exacerbating the incidence of ACL injury in collegiate athletes both within games and across the season.