ACL injuries in men's professional football: a 15-year prospective study on time trends and return-to-play rates reveals only 65% of players still play at the top level 3 years after ACL rupture

Pain Catastrophizing, Beliefs and Perception, and Their Association With Profiling Characteristics in Athletes

CONTEXT

Variables associated with pain catastrophizing and beliefs in athletes presenting with musculoskeletal pain and/or sports-related injuries are largely unexplored.

OBJECTIVE

We aimed to evaluate which anthropometric, sociodemographic, sporting, injury history, and care-seeking characteristics were associated with the Pain Catastrophizing Scale (PCS) and Pain Beliefs and Perceptions Inventory (PBAPI) scores in athletes.

DESIGN

This study followed a cross-sectional design.

METHODS

Three hundred and twelve athletes (40% females) from different sports and levels completed a questionnaire including demographic information, details regarding sports practice, injury history, health care use, PCS, and PBAPI. Univariable associations between PCS and PBAPI scores and each variable were assessed using linear regression. Variables with univariable associations where P < .05 were entered into multivariable regression models.

RESULTS

The final multivariable model including gender, recurrent and persistent pain, a history of a severe atraumatic injury, and a history of more than 5 atraumatic injuries explained 14.9% of the variance in PBAPI scores. Performing a team sport and a history of more than 5 atraumatic injuries explained 5.1% of the variance in PCS scores.

CONCLUSIONS

Gender, sporting, and injury history characteristics explained only a small portion of the variance in PCS and PBAPI scores, whereas having received healthcare support and the number of appointments did not. Most of the variance was left unexplained.

Isolated ACL Reconstruction Versus Combined ACL and Anterolateral Ligament Reconstruction: Functional Outcomes, Return to Sport, and Survivorship: An Updated Meta-analysis of Comparative Studies

BACKGROUND

Failure, persistent knee instability, and reinjury rates after anterior cruciate ligament (ACL) reconstruction are still concerns. Biomechanical investigations have highlighted the role of the anterolateral ligament (ALL) as a crucial knee stabilizer, and clinical outcomes after combined ACL and ALL reconstruction appear to indicate the success of the procedure.

PURPOSE

To compare the functional outcomes, return-to-sport (RTS) rate, and complications between combined ACL and ALL reconstruction and isolated ACL reconstruction.

STUDY DESIGN

Meta-analysis; Level of evidence, 4.

METHODS

The PubMed/MEDLINE, Scopus, and Cochrane Central databases were used to search keywords, and a total of 16 studies were included. The data extracted for quantitative analysis included the Tegner activity scale score, Lysholm knee score, International Knee Documentation Committee (IKDC) score, laxity measured using the KT-1000 knee arthrometer, number and types of complications, RTS rate, and survival rate. Random- and fixed-effects models were used for the meta-analysis of pooled mean differences and odds ratios.

RESULTS

A total of 2329 patients were identified, 1116 of whom underwent combined ACL and ALL reconstruction and 1213 of whom underwent isolated ACL reconstruction. The mean ages were 25.4 ± 7.2 years and 26.5 ± 7.8 years for the combined ACL and ALL reconstruction and isolated ACL reconstruction groups, respectively. The mean follow-ups were 40.3 ± 21.4 months and 42.5 ± 21.6 months, respectively. Comparable Tegner activity scale (P = .16), Lysholm knee (P = .13), and IKDC (P = .83) scores were found between groups. Significantly greater postoperative knee laxity was found in the isolated ACL reconstruction group (mean difference, -0.44; 95% CI, -0.85 to -0.04; P = .03). The combined ACL and ALL reconstruction group showed a significantly lower rate of graft failure (odds ratio [OR], 0.37; 95% CI, 0.18-0.77; P = .008), a higher RTS rate (OR, 1.41; 95% CI, 1.11-1.80; P = .005), and a higher survival rate (OR, 2.94; 95% CI, 1.97-4.37; P < .001).

CONCLUSION

Compared with isolated ACL reconstruction, combined ACL and ALL reconstruction yielded comparable functional outcomes but significantly less residual knee laxity and a lower graft failure rate. Patients who underwent combined ACL and ALL reconstruction also had higher RTS and survival rates.

Anterior Cruciate Ligament Injury Does Not Increase the Risk for a Future Concussion: A Unidirectional Phenomenon

CONTEXT

Epidemiological studies have shown an increased risk of musculoskeletal injury after concussion. The purpose of this study was to determine whether the reverse relationship exists, specifically whether there is an increased risk of concussion after an anterior cruciate ligament (ACL) injury in a population-based cohort.

DESIGN

Retrospective cohort.

METHODS

The Rochester Epidemiology Project was searched between 2000 and 2017 for International Classification of Diseases, 9th and 10th Revision codes relevant to the diagnosis and treatment of concussion and ACL tear. A total of 1294 unique patients with acute, isolated ACL tears and no previous history of concussion were identified. Medical records for cases were reviewed to confirm ACL tear diagnosis and to determine history of concussion after the ACL injury. Cases were matched by age, sex, and Rochester Epidemiology Project availability to patients without an ACL tear (1:3 match), resulting in 3882 controls. Medical records of matched control patients were reviewed to rule out history of ACL injury. The hazard ratio of concussion injury following an ACL injury was determined.

RESULTS

Nine patients with an ACL injury suffered concussion up to 3 years after the ACL injury. The rate of concussion was no different between ACL-injured cases (0.7%) compared with matched controls with no ACL injury (1.2%), which corresponded to a hazard ratio of 0.55 (95% confidence interval, 0.3-1.1; P = .10).

CONCLUSIONS

Based on the current evidence, there does not appear to be a significant association between ACL injury and subsequent concussion, which suggests that a concussion uniquely affects the risk of future subsequent musculoskeletal injury.

High Return to Competition Rate After On-Field Rehabilitation in Competitive Male Soccer Players After ACL Reconstruction: GPS Tracking in 100 Consecutive Cases

Background

Despite published guidelines describing on-field rehabilitation (OFR) frameworks for soccer, available evidence for practitioners who work with players with anterior cruciate ligament reconstruction (ACLR) is limited.

Purpose

To document the activity and workloads completed by a large cohort of amateur and professional soccer players during OFR following ACLR after completing their indoor rehabilitation and to establish their return to competition (RTC) outcomes.

Study Design

Case series; Level of evidence, 4.

Methods

OFR measurements/activities, global positioning system (GPS), and heart rate data were collected from 100 male 11-a-side soccer players with ACLR undergoing a criteria-based rehabilitation process, concluding with a 5-stage OFR program. Consent was obtained directly from the players involved in this study before completing a follow-up questionnaire to document RTC outcomes. Differences between the level of play (professional and amateur) and 5 OFR stages were investigated using separate linear mixed models.

Results

A minimum 9-month follow-up was possible for 97 players (97%), with a median time of 2.3 years after ACLR and 84% RTC, with higher rates in professionals (100%) than amateurs (80%). Ten (10%) players sustained an ACL reinjury. Professionals completed more OFR sessions (20.6 ± 7.7 vs 13.2 ± 7.7; P < .001) over a shorter period (44.7 ± 30.3 vs 59.3 ± 28.5 days; P = .044) and achieved higher workloads mostly in the high-intensity GPS metrics in each OFR stage. Typical external workload outputs in the final OFR stage aligned with team training demands for the total distance (TD) (106%), high-intensity distance (HID) (104%), peak speed (PS) (88%), acceleration distance (ACC) (110%), and deceleration distance (DEC) (48%), but they were lower compared with match play demands (TD: 44%; HID: 51%; PS: 82%; ACC: 63%; and DEC: 26%).

Conclusion

High RTC rates were reported in those players who participated in OFR after indoor rehabilitation. Completion of all five OFR stages almost prepared them for team training demands; however, workloads remain low compared to match play.

3D kinematics of noncontact and indirect contact ACL injuries in elite male football players

PURPOSE

Our primary goal was to deepen the understanding of the mechanisms leading to anterior cruciate ligament (ACL) injuries by reconstructing the three-dimensional (3D) joint kinematics of ACL injuries that occurred in professional male football matches. In particular, we aimed to compare the time courses of trunk and injured limb joint angles between noncontact and indirect contact injury mechanisms.

METHODS

In this cross-sectional observational study, we analysed a total of 27 cases (18 noncontact, 9 indirect contact). Whole-body 3D kinematics preceding and during ACL injuries was reconstructed using the Model-Based Image-Matching technique, implemented in Blender. For each injury, television footage from multiple perspectives (≥2, nine frames per view) were used, and Euler's joint angles across all the anatomical planes were extracted. The joint angle time courses of both the trunk and the injured limb, comprising 12 waveforms in total, were compared between injury mechanisms and Statistical Parametric Mapping was used to detect significant clusters.

RESULTS

Compared to noncontact injuries, indirect contact cases showed a lower hip abduction (-16°, p = 0.003), knee internal rotation (~3°, p < 0.001) at the initial contact with the ground, and ankle dorsiflexion (~7°, p = 0.035) at instants before the initial ground contact. These differences resulted from the player's adaptation to the sudden (yet variable) mechanical perturbation due to the contact with the opponent.

CONCLUSION

Mechanical interactions with other players impact segmental kinematics before and during ACL injuries in professional male football. These findings reinforce the importance of considering the sport-specificity of mechanisms in injury prevention.

LEVEL OF EVIDENCE

Level IV.

The Impact of a Concomitant Meniscus Surgery on Hop Performance Symmetry in Patients Rehabilitating After Anterior Cruciate Ligament Reconstruction

Background

Meniscus injuries often accompany anterior cruciate ligament (ACL) tears. However, little is known about how different surgical approaches to treat concomitant meniscus injuries impact hop performance after ACL reconstruction. Purpose: The purpose of this study was to compare hop test inter-limb symmetry for patients who had undergone ACL reconstruction without an associated meniscal surgery, patients who had undergone ACL reconstruction with a meniscus repair, and patients who had undergone ACL reconstruction with a partial meniscectomy.

Study Design

Cross-sectional study.

Methods

Hop test data collected at the time of return-to-sport testing (average of 6.4 ± 1.4 months after surgery) was extracted from electronic medical records for 192 patients who had undergone ACL reconstruction. Of these patients, 102 had undergone an isolated ACL reconstruction, 60 had undergone an ACL reconstruction along with a meniscus repair, and 30 had undergone an ACL reconstruction along with a partial meniscectomy. Analysis of variance was used to compare limb symmetry indices for the single- and triple-hop tests. These limb symmetry indices reflected the ratio of the hop distance for the involved limb relative to the uninvolved limb, expressed as a percentage.

Results

The sample was comprised of 100 males and 92 females. Their average age was 20.6 ± 8.2 years. There were significant differences among the groups for the single-hop test (p = 0.031) and triple-hop test (p = 0.024) limb symmetry indices. For both tests, the patients who had undergone ACL reconstruction with a partial meniscectomy tended to exhibit greater deficits in hop performance for their involved limb (relative to their uninvolved limb), compared to those without a meniscal injury and those who had undergone meniscus repair.

Conclusions

The results of this study suggest that patients who undergo ACL reconstruction along with a partial meniscectomy tend to experience less complete and/or delayed recovery of involved-limb hop performance, which could reflect more persistent deficits in lower body power.

Level of Evidence

3.

Systematic Video Analysis of ACL Injuries in Male Professional English Soccer Players: A Study of 124 Cases

Background

Improving our understanding of the situations and biomechanics that result in anterior cruciate ligament (ACL) injury will support the design of effective injury risk mitigation programs. A few video analyses have been published in recent years, but not specifically involving English soccer.

Purpose

To describe the mechanisms, situational patterns, and biomechanics (kinematics) of ACL injuries of players involved in matches involving teams in the top 2 tiers of professional English soccer (the Premier League and the Championship).

Study Design

Case series; Level of evidence, 4.

Methods

We identified 148 consecutive ACL injuries across 11 seasons of professional English soccer. Overall, 124 (84%) injury videos were analyzed for mechanism and situational patterns, while biomechanical analysis was possible in 91 injuries. Three independent reviewers evaluated each video. ACL injury epidemiology (month, timing within the match, and location on the playing field at the time of injury) was also reported.

Results

More injuries occurred in defensive (n = 79; 64%) than offensive (n = 45; 36%) playing situations; 24 (19%) injuries were direct contact, 52 (42%) indirect contact, and 47 (38%) noncontact. Of the indirect and non-contact ACL injuries (n = 100), most (91%) occurred during 4 main situational patterns: (1) pressing/tackling (n = 50; 50%); (2) being tackled (n = 18; 18%), (3) landing from a jump (n = 13; 13%), and (4) regaining balance after kicking (n = 10; 10%). These injuries generally involved a knee flexion strategy (with minimal hip/trunk flexion and reduced plantarflexion) in the sagittal plane and appearance of knee valgus in most cases (70%; 96% of identifiable cases). More (n = 71; 57%) injuries occurred in the first half of matches than in the second half (P < .01).

Conclusion

Indirect contact rather than noncontact was the main ACL injury mechanism in male elite English soccer players. Four main situational patterns were described, with pressing/tackling and being tackled accounting for two-thirds of all indirect and noncontact injuries. Biomechanical analysis confirmed a multiplanar mechanism, with knee loading patterning in the sagittal plane accompanied with dynamic valgus. More injuries occurred in the first half of matches.

Knee pain and function in retired male intercounty GAA players: an exploratory study

BACKGROUND

Knee injuries are common among elite intercounty Gaelic games players (collectively GAA players).

AIMS

The primary aim was to examine knee pain, function, and quality of life in retired elite male GAA players. Secondary objectives were to (i) report the incidence of previous knee surgery and total knee replacement, (ii) assess medication usage, and (iii) investigate any associations between a history of knee injury and/or knee surgery and knee pain, function, and quality of life among retired elite male GAA players.

METHODS

One hundred retired male senior intercounty GAA players were surveyed on their history of severe knee injury and previous knee surgery (68 completed survey; 47 Gaelic football, 20 hurling, 1 dual player). The Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS) and the Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) were used to assess level of function and pain.

RESULTS

Forty-seven (69%) of the retired players described experiencing at least one severe knee injury during their intercounty career. Fourteen (21%) participants retired due to a significant knee injury. Mean KOOS-SP score was 75.5 (SD 17). The Global Physical Health and Global Mental Health mean scores were 44 and 51. There was a low negative correlation between KOOS-SP scores and a history of severe knee injury (r = -0.35, p = 0.001). Moderate negative correlation between Global Mental Health scores and a history of severe knee injuries (r = -0.36, p = 0.386) and a very weak negative correlation between the number of surgeries during a participant's intercounty career and Global Mental Health score (r = -0.089, p = 0.234).

DISCUSSION

Severe knee injuries and knee surgery are common among male intercounty GAA players. These injuries lead to self-reported reduced performance and retirement and are potentially associated with worse health-related outcomes post-intercounty career. Further well-designed studies, including among retired women GAA players, are required to assess the relationship between knee injuries and long-term athlete outcomes. Improved injury prevention efforts, enhanced rehabilitation of knee injuries, and post-retirement care may mitigate the adverse effects associated with severe knee injuries among male GAA players.

Return to competition after ACL reconstruction: Factors influencing rates and timing in Swedish football players

PURPOSE

To investigate the rate and timing for return to football league games after anterior cruciate ligament reconstruction (ACLR) in Swedish players, examining associations with sex, age, level, graft and additional ACL surgery.

METHOD

Data from the Swedish National Knee Registry (SNKLR) and the Swedish Football Association's IT System (FOGIS) were used. The study cohort comprised 971 football players, 64% males, who underwent primary ACLR. Demographics, graft type and surgical information were extracted from the SNKLR and game participation from FOGIS. Follow-up for return to competition (RTC) was conducted for 36 months, while additional ACLR follow-up was 3-7 years. Statistical analyses, including Kaplan-Meier survival curves and relative risk calculations, were employed to assess factors influencing RTC rates and timing.

RESULTS

Out of 971 players analyzed, 53% RTC within 3 years with no difference between males and females, at a mean of 15 months (median 14 months) from surgery to the first game. Eleven (2%) players RTC < 6 months from ACLR, 62 (12%) 6-9 months, 125 (24%) 9-12 months and 331 (63%) >12 months. Patellar tendon (PT) grafts demonstrated superior performance, showing quicker returns and higher RTC rates (p = 0.005) compared to hamstring (hazard ratio [HR]: 0.63 [0.48-0.84]) and quadriceps tendon grafts (HR: 0.53 [0.30-0.93]). Players competing in higher divisions pre-injury experienced significantly swifter and higher RTC rates (p < 0.001). Ninety-five (10%) had a registered additional ACLR. Players who RTC did not exhibit a significantly higher rate of revision (35 [7%] vs. 25 [5%]). However, those who returned faced a heightened risk of contralateral ACLRs compared to those who did not RTC (32 [6%] vs. 4 [1%] RR 1.72 [1.59-1.96], p < 0.001).

CONCLUSION

The study reveals that 53% of football players RTC after ACLR, predominantly after more than 12 months. The RTC was higher and faster in high-level players and those receiving a PT graft. The slow RTC may contribute to the relatively low rate of additional ACLRs.

LEVEL OF EVIDENCE

Level III.

Cortical changes associated with an anterior cruciate ligament injury may retrograde skilled kicking in football: preliminary EEG findings

Anterior cruciate ligament injuries (ACLi) impact football players substantially leading to performance declines and premature career endings. Emerging evidence suggests that ACLi should be viewed not merely as peripheral injuries but as complex conditions with neurophysiological aspects. The objective of the present study was to compare kicking performance and associated cortical activity between injured and healthy players. Ten reconstructed and 15 healthy players performed a kicking task. Kicking biomechanics were recorded using wearable inertial measurement unit sensors. Cortical activity was captured with a 64-electrode mobile electroencephalography. Multiscale entropy (MSE) analysis of biomechanics revealed increased variability in foot external rotation among injured players. Source-derived event-related spectral perturbations indicated significant differences in posterior alpha and frontal theta oscillations between the two groups. Furthermore, kick-related complexity of these regions as indexed by MSE was reduced in injured players at medium and coarse scales. Our findings suggest sensorimotor changes during kicking in injured players, which may necessitate compensatory strategies involving augmented attention at the cost of processing visuospatial information. This conflict may hinder the integration of task-relevant information across distributed networks. Our study provides preliminary insights into the neurophysiological implications of ACLi within football context and underscores the potential for prospective research.

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

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

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

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

The Time Course of Injury Risk After Return-to-Play in Professional Football (Soccer)

BACKGROUND

Injury risk in professional football (soccer) is increased in the weeks following return-to-play (RTP). However, the time course of injury risk after RTP (the hazard curve) as well as its influencing factors are largely unknown. This knowledge gap, which is arguably due to the volatility of instantaneous risk when calculated for short time intervals, impedes on informed RTP decision making and post-RTP player management.

OBJECTIVES

This study aimed to characterize the hazard curve for non-contact time-loss injuries after RTP in male professional football and to investigate the influence of the severity of the index injury and playing position.

METHODS

Media-based injury records from the first German football league were collected over four seasons as previously published. Time-to-event analysis was employed for non-contact time-loss injury after RTP. The Kaplan-Meier survival function was used to calculate the cumulative hazard function, from which the continuous hazard function was retrieved by derivation.

RESULTS

There were 1623 observed and 1520 censored events from 646 players analyzed. The overall shape of the hazard curve was compatible with an exponential decline of injury risk, from an approximately two-fold level shortly after RTP towards baseline, with a half-time of about 4 weeks. Interestingly, the peak of the hazard curve was slightly delayed for moderate and more clearly for severe index injuries.

CONCLUSIONS

The time course of injury risk after RTP (the hazard curve) can be characterized based on the Kaplan-Meier model. The shape of the hazard curve and its influencing factors are of practical as well as methodological relevance and warrant further investigation.

High incidence of anterior cruciate ligament injuries in professional men's handball: Analysis of the 'ACL registry in German Sports' over seven consecutive seasons

PURPOSE

The purpose of this study was to generate knowledge about the epidemiology and risk factors for anterior cruciate ligament (ACL) injuries in handball. It was hypothesised that the incidence of ACL injuries is high and comparable to other pivoting sports like football.

METHODS

This study is based on the prospective 'ACL registry in German Sports' implemented in the 2016-2017 season. Professional (first and second leagues) male handball players were analysed regarding the incidence and risk factors for ACL injuries. Injuries were registered according to the direct reports of the injured players to the study office and double-checked via media analysis. After injury registration, the players received a standardised questionnaire. Data were analysed from the 2016-2017 to the 2022-2023 season.

RESULTS

A total of 84 ACL injuries were registered. 46.3% of ACL injuries were re-ruptures. This represents a total incidence of 0.044 ACL injuries per 1000 h of exposure in training and matches per player over the study period. An increased incidence rate of 0.064/1000 h in the first league compared to 0.031/1000 h in the second league was reported (p ˂ 0.001). The mean number of injuries in the first division was 8.3, and in the second division, 6.6 ACL ruptures per season. Risk factors for ACL injury include previous knee injury and increased match exposure.

CONCLUSION

The incidence of ACL injuries in professional handball is high and comparable to football with an increased risk in the first league compared to the second league in Germany. There was a high incidence of re-injury. Other risk factors for ACL injuries include previous injuries to the affected knee in general as well as increased match exposure.

LEVEL OF EVIDENCE

Level II prospective cohort study.

The "11 to Perf Score", a Test for Professional Players Returning to Soccer After Anterior Cruciate Ligament Reconstruction

Rupture of the anterior cruciate ligament (ACL) is common among soccer players. Although there are no strict recommendations for the return to sport, more and more practitioners are having their patients perform isokinetic and even composite tests. However, these tests have not yet been shown to be predictive of re-injury, and are not specific to professional footballers. Objectives: The "11 to Perf" is a test designed to help professional footballers return to sport after ACL reconstruction. Its originality lies in its integration of soccer practice with specific tests. The aim of this article is to present the "11 to Perf" evaluation method. Methods: A prospective cohort study was conducted at the Centre National du Football (FIFA center) in Clairefontaine, including professional footballers who have undergone anterior cruciate ligament surgery and rehabilitation. Tests include clinical assessments, jumping, agility, psychological and isokinetic tests and match simulation. Conclusions: The "11 to Perf" is a composite test designed to assess the return to sport of professional footballers after ACL reconstruction. Its predictive capacity for recurrence should be assessed in the future.

Verbal instructions for attentional focus influence the results of tests for return to sport after anterior cruciate ligament reconstruction

This cross-sectional study investigated the influence of attentional focus verbal instructions on test results for return to sport (RTS) after ACL-R. Sixty subjects (53 male and 7 female, age 27.52 ± 7.63 years, body mass 77.56 ± 12.41 kg, height 162.04 ± 43.90 cm, and surgery time 11.15 ± 4.55 months) were evaluated in the single hop test (SHT), 6 m timed hop test (6mTHT), and "T" agility test. Participants performed the tests following randomly determined verbal instructions that induced neutral focus (NF), internal focus (IF), and external focus (EF). EF increased hop distance in SHT compared to NF (p = 0.001, effect size = 0.57) and IF (p = 0.037, effect size = 0.57) and there was no difference between IF and NF (p = 0.418). In 6mTHT, NF and EF increase velocity compared to IF (p = 0.001, effect size = 0.49, p = 0.001, effect size = 0.49, respectively). In the "T" agility test, the NF increased velocity when compared to the EF (p = 0.001, effect size = 0.62) and the IF (p = 0.001, effect size = 0.62), without difference between IF and EF (p = 0.071). In summary, attentional focus in patients under ACL-R can influence hops and agility.

Functional Deficits in Non-elite Soccer (Football) Players: A Strength, Balance, and Movement Quality Assessment After Anterior Cruciate Ligament Reconstruction

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction (ACLR) is the gold standard for treating ACL injuries, particularly in soccer players who are at a high risk of knee injury. While professional athletes often return to sport (RTS) within 7-10 months after ACLR, non-elite players experience significant delays. There is a need to investigate neuromuscular deficits and functional asymmetries in the non-elite group, which may persist even after clearance for RTS. This study aims to evaluate the functional movement patterns, single-leg balance, and isokinetic knee strength in non-elite soccer players preparing to RTS. Additionally, correlations between the aforementioned parameters were explored.

METHODS

A cohort of 69 male, non-elite soccer players (mean age: 24.32±8.56 years) who underwent ACLR with a hamstring graft was recruited. Functional assessments were conducted at the mean time of nine months post-surgery, and all participants were clinically cleared by the surgeon. The evaluation included the Functional Movement Screen™ (FMS), single-leg balance tests (SLBT) on stable and unstable platforms, and isokinetic strength tests (IST) for knee flexion and extension at 60 deg·s-1 and 180 deg·s-1. Limb symmetry indices (LSIs) were calculated. Statistical analyses included t-tests, Mann-Whitney U tests, and Spearman correlations.

RESULTS

The mean FMS score was 15.45±2.23, indicating moderate functional movement quality. SLBT results revealed no significant (P>0.05) inter-extremity differences in stability indices, regardless of platform setting (stable or unstable). However, significant deficits in quadriceps and hamstring strength were observed in the ACLR extremity. At 60 deg·s-1, the mean peak torque/body weight (PT/BW) ratio for knee extension was 2.01±0.65 Nm.kg-1 for the ACLR side versus 2.60±0.57 Nm.kg-1 for the contralateral side (P<0.0001). Similar asymmetries were observed at 180 deg·s-1 (1.51±0.44 vs. 1.88±0.35 Nm.kg-1; P<0.0001). LSIs for quadriceps were markedly reduced, averaging 76.97±17.72% at 60 deg·s-1 and 79.89±17.11% at 180 deg·s-1. At 60 deg·s-1, the mean PT/BW ratio for knee flexion was 1.24±0.34 Nm.kg-1 for the ACLR side versus 1.39±0.32 Nm.kg-1 for the contralateral side (P=0.009) at 180 deg·s-1 (1.03±0.27 vs. 1.16±0.25 Nm.kg-1; P=0.003). LSIs for the hamstring were averaging 89.34±13.91% at 60 deg·s-1 and 88.44±14.58% at 180 deg·s-1. Weak negative correlations were found between FMS scores and stability indices (e.g., r=-0.26 for overall stability index on unstable platform; P=0.031), while moderate positive correlations were observed between PT/BW ratios and FMS scores (r=0.36-0.60; P<0.001).

CONCLUSIONS

Significant strength asymmetries in quadriceps and hamstring muscles persist in non-elite soccer players after ACLR. While balance deficits were minimal, weak correlations between FMS scores and stability indices suggest a link between functional movement quality and dynamic control. These findings highlight the need for targeted strength training in rehabilitation and the importance of comprehensive assessments, including functional performance tests, strength evaluations, and balance analysis, to ensure safe RTS. Achieving clinical clearance does not equate to full recovery, emphasizing the necessity for a multidimensional approach to RTS decisions.

Effect of foot strike patterns and angles on the biomechanics of side-step cutting

Objectives

The study aimed to determine how foot strike patterns and cutting angles affect lower extremity (LE) kinematics, kinetics, and muscle activity during side-step cutting.

Methods

Twenty male college sport athletes participated in this research. Three-dimensional motion analysis featuring ground reaction force (GRF) and electromyography (EMG) of the dominant leg was used. LE kinematics, kinetics, and EMG data parameters were obtained during a 45° and 90° side-step cutting involving rearfoot strikes (RFS) and forefoot strikes (FFS).

Results

The significant foot strike pattern × angle interactions were observed for the ankle eversion range of motion (ROM) at the loading phase. Cutting of 90° had greater knee flexion ROM, knee valgus ROM, and knee varus moment compared to that of 45°. RFS cutting had greater knee flexion, hip flexion, knee valgus, knee varus moment, knee varus moment, and ankle eversion ROM. FFS cutting produced a lower vertical GRF, lateral GRF, and a loading rate. Both vastus medialis and vastus lateralis muscle activities were remarkably greater during cutting of 90° than 45°. At the loading phase, semitendinosus, biceps femoris, and the lateral head of gastrocnemius muscle activities during FFS cutting were considerably greater than those during RFS cutting.

Conclusion

The FFS pattern can better protect the anterior cruciate ligament (ACL) and improve the flexibility of athletes by increasing the plantarflexion torque of the ankle. The injury risk also increases with the larger cutting angle. The EMG activities of semitendinosus and biceps femoris are vital for the stability of knee joint during side-step cutting, which helps reduce ACL stress during buffering.

A mechanical comparison of the translational traction of female-specific and male soccer boots

The studded outsole of a soccer boot provides additional traction to players to minimise the risk of slipping while performing high-speed manoeuvres. As excessive traction can lead to foot fixation and injury risk, there has been significant research surrounding the influence of stud configuration on the level of traction generated. This previous research, however, has predominately focused on the stud patterns, foot morphology and lower limb loading patterns of male players. As the popularity of women's soccer increases, the aim of this investigation was to examine the differences in translational traction of female-specific soccer boots and male soccer boots currently available. A custom-built apparatus was used to determine the translational traction on both natural and artificial grass for four different movement directions. It was hypothesised that the female-specific boot in each pair would produce lower levels of translational traction as they are designed to be safer for female players who are more at risk of lower limb fixation injuries compared to males. An independent samples T-test showed that while there were some loading conditions where female boots produced lower translational traction compared to male boots, across all loading scenarios there was no significant difference between male and female boots (p = 0.818), thus the null hypothesis was rejected.

Effects of stiffness-altered sport compression garments on lower-limb biomechanics in cutting maneuvers

Athletes commonly use compression garments (CGs) for perceived effectiveness in preventing injury occurrence. However, limited evidence is available on whether lower-limb CGs reduce the risk of injury. This study aimed at (1) evaluating the effects of CGs on mitigating the risk factors of cutting-related knee injuries; (2) identifying undesirable side-effects of CGs on other joints and cutting performance; and (3) identifying possible interactions between sex and condition. 62 healthy adults performed pre-planned 90˚ cutting tasks under four conditions: control, knee sleeves, placebo leggings and stiffness-altered leggings. Joint angle at initial contact, range of motion, moments, and ground reaction force were measured. A mixed two-way (sex*condition) ANOVA was performed, followed by post-hoc comparisons and subset analyses for sexes. Results showed that the leggings restricted hip sagittal (45.4 ± 1.3 vs. control 50.0 ± 1.3˚, p = 0.001) and rotational (16.8 ± 0.8 vs. control 22.5 ± 1.1˚, p < 0.001) motion. At initial contact, the stiffness-altered leggings reduced knee valgus (0.4 ± 0.8 vs. control -2.1 ± 0.8˚, p = 0.031). However, the altered alignment of lower-limb joints did not reduce multiplanar knee joint moments (p > 0.05). CGs were not effective protective equipment yet. There was no significant difference between knee sleeves and control, nor between leggings conditions (p > 0.05). Force plate measurements, such as increased rate of force development (stiffness-altered 42.6 ± 1.1 & placebo 42.9 ± 1.1 vs. control 39.9 ± 1.0 BW/s, p < 0.028), implied the possibility of performance enhancement through CGs. While further investigations on the optimal compression and stiffness alterations are warranted, athletes are recommended to be aware of the discrepancies between the claimed and actual biomechanical effects of CGs.

Factors Associated With a Successful Return to Performance After Anterior Cruciate Ligament Reconstruction: A Multiparametric Evaluation in Soccer Players

Background

Anterior cruciate ligament reconstruction (ACLR) is highly recommended in patients with ACL deficiency who must perform at a high physical level. A combination of functional and psychological outcome measures is necessary to provide a comprehensive evaluation of functional status after successful return to sport after ACLR.

Purpose

To identify factors associated with higher functional outcomes among soccer players who had returned to full sports participation after ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 168 out of 231 patients who underwent primary unilateral arthroscopic anatomic single-bundle ACLR were available at follow-up. Postoperatively, knee function, generic health outcomes, and psychological impact were assessed using the International Knee Documentation Committee (IKDC), the Knee injury and Osteoarthritis Outcome Score (KOOS), the Lysholm Knee Scoring Scale, the 12-item Short Form Health Survey (SF-12), and the ACL-Return to Sport after Injury scale.

Results

After a mean follow-up of 35.5 ± 22.6 months, 85% of soccer players returned to performance. Midfielder position was associated with a better SF-12 Physical Component Summary (PCS) score (P = .013), IKDC (P = .003), total KOOS (P < .001), KOOS Symptoms (P = .004), KOOS Pain (P = .029), KOOS Activities of Daily Living (ADL) (P = .044), KOOS Sport and Recreation (Sport/Rec) (P = .001), KOOS Quality of Life (QoL) (P < .001), and Lysholm score (P = .008). Playing only on natural grass was associated with lower SF-12 PCS scores (P = .003), total KOOS (P = .001), and KOOS Sport/Rec (P = .011). Playing only on artificial turf was associated with lower Lysholm score (P = .018) and total KOOS (P = .014). The contact mechanism was associated with higher IKDC (P = .044) and KOOS QoL (P = .048), and injury affecting the dominant limb was associated with lower SF-12 Mental Component Summary scores (P = .012). Playing at a nonprofessional level was associated with lower total KOOS (P = .028), KOOS Symptoms (P = .002), KOOS ADL (P = .033), and KOOS Sport/Rec (P = .016).

Conclusion

Professional soccer players and the midfielder position are associated with better functional scores upon returning to the sport. A history of noncontact ACL injury and playing on a single type of surface are associated with lower functional outcomes upon returning to the sport. Lower mental health scores can be expected after injury of the dominant limb.

Machine learning in knee injury sequelae detection: Unravelling the role of psychological factors and preventing long-term sequelae

Purpose

This study evaluated the performance of three machine learning (ML) algorithms-decision tree (DT), multilayer perceptron (MLP) and extreme gradient boosting (XGB)-in identifying regular athletes who suffered a knee injury several months to years prior. In addition, the contribution of psychological variables in addition to biomechanical ones in the classification performance of the ML algorithms was assessed, to better identify factors to get back to competitive sport with the lowest possible risk of new knee injury.

Methods

A cohort of 96 athletes, 36 with prior knee injuries, practicing an average of 5.7 ± 2.4 h per week, participated in a horizontal force-velocity test on a ballistic ergometer providing data of force, velocity and power from each lower limb. They also completed a psychological questionnaire, which included components from the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Sport Anxiety Scale (SAS). The three ML algorithms were trained on a thousand different train-test sets. Also, Shapley values were calculated for each input variable of a data set to highlight its contribution to the prediction from an ML model.

Results

Over a thousand cross-validations, higher area under the curve (AUC) values were obtained when accounted for the psychological attributes (p < 0.001). Also, higher AUC values were obtained from MLP compared to XGB or DT (p < 0.001). XGB exhibited higher AUC values than DT (p < 0.001).

Conclusions

Our results suggested that psychological factors play a more important role in recognition than biomechanical factors, with KOOS and SAS scores ranking high in the list of influential factors. Additionally, the computing stability of MLP could be recommended for classification tasks in the context of knee injuries.

Level of Evidence

Level III.

Systematic video analysis of ACL injuries in professional Spanish male football (soccer): injury mechanisms, situational patterns, biomechanics and neurocognitive errors - a study on 115 consecutive cases

Objective

A few video analysis studies have been published in recent years, but none specifically on Spanish football. We aimed to describe the mechanisms, situational patterns, biomechanics and neurocognitive errors related to anterior cruciate ligament (ACL) injuries in professional Spanish football matches.

Methods

We identified 167 consecutive ACL injuries across 12 seasons of the top two leagues in Spanish football. 115 (69%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 81 cases. Neurocognitive errors were investigated for all non-contact injuries. Three independent reviewers evaluated each video. ACL injury epidemiology-month, timing within the match and pitch location at the time of injury was also documented.

Results

More injuries occurred in defensive (n=68, 59%) than offensive (n=48, 41%) (p<0.01) playing situations. 16 (14%) injuries were direct contact, 49 (43%) indirect contact and 50 (43%) non-contact. Most injuries (89%) occurred during four main situational patterns: (1) pressing/tackling (n=47, 47%); (2) tackled (n=23, 23%); (3) landing from a jump (n=12, 12%) and regaining balance after kicking (n=6, 6%). Injuries generally involved a knee-dominant loading strategy in the sagittal plane with abducted hip and knee valgus. Of the non-contact injuries, 39 (78%) were deemed to involve a neurocognitive error. More (58%) injuries occurred in the first half of matches (p<0.01).

Conclusions

ACL injuries in Spanish football occurred similarly with non-contact and indirect contact mechanisms (44%). Four in five non-contact injuries involved a neurocognitive error. Most injuries occurred during four previously identified situational patterns, with more injuries earlier in the match.

An injury burden heat map of all men's and women's teams of a professional football club over a decade

The aim was to present a descriptive 10-season summary of injury data from all teams of a professional football club using a heat map approach. Injuries and exposure time were registered according to the FIFA consensus in all men's and women's teams from Athletic Club over 10 seasons. A team-by-injury table was created, showing the incidence, median severity, and burden in each cell. Cells were coloured based on the injury burden value using a green - yellow-red gradient (lowest to highest). The highest overall injury burden was found in the women's 2nd and 1st teams and the men's U(under)17 team (>200 days lost/1000 h). Muscle injury burden demonstrated an increasing pattern with age. Knee joint/ligament injuries, particularly anterior cruciate ligament ruptures, had the highest impact on women's teams, followed by the men's 2nd team. In comparison, ankle joint/ligament injuries had a relatively low injury burden in most teams. Growth-related injuries were the most impactful injuries in the men's U15 and younger teams, and the women's U14 team. In conclusion, epidemiological data on injuries can inform and guide injury management processes. New and improved visualization methods might be important assets when presenting injury data to key decision-makers.

ACL Injury Etiology in Its Context: A Systems Thinking, Group Model Building Approach

Background/Objectives: Given the complex nature of Anterior Cruciate Ligament (ACL) injury, it is important to analyze its etiology with suitable approaches in order to formulate intervention strategies for effective prevention. The present study employs system thinking techniques to develop a Causal Loop Diagram (CLD) Model for investigating the risk factors for ACL Injury (CLD-ACLI), through a Group Model Building approach. Methods: A two-stage procedure was applied involving a comprehensive literature review followed by several systems thinking group-modeling co-creation workshops with stakeholders. Results: Based on input from experts and stakeholders, combined with the latest scientific findings, the derived CLD-ACLI model revealed a series of interesting complex nonlinear interrelationships causal loops between the likelihood of ACL injury and the number of risk factors. Particularly, the interaction among institutional, psychological, neurocognitive, neuromuscular, malalignment factors, and trauma history seem to affect neuromuscular control, which subsequently may alter the biomechanics of landing, predisposing the ACL to injury. Further, according to the proposed CLD-ACLI model, the risk for injury may increase further if specific environmental and anatomical factors affect the shear forces imposed on the ACL. Conclusions: The proposed CLD-ACLI model constitutes a rigorous useful conceptual presentation agreed upon among experts on the dynamic interactions among potential intrinsic and extrinsic risk factors for ACL injury. The presented causal loop model constitutes a vital step for developing a validated quantitative system dynamics simulation model for evaluating ACL injury-prevention strategies prior to implementation.

Return to Play and Performance After Anterior Cruciate Ligament Reconstruction in Soccer Players: A Systematic Review of Recent Evidence

BACKGROUND

The available literature referring to the return to play (RTP) and performance after anterior cruciate ligament reconstruction (ACLR) has already been comprehensively summarized in team sports such as basketball or American Football. Therefore, in this sense, it is necessary to synthesize evidence relating to the mentioned parameters in soccer players who underwent ACLR.

OBJECTIVE

The aim of this systematic review was to examine RTP and the performance of soccer players after ACLR.

METHODS

Three electronic databases, Web of Science, Scopus, and PubMed, have been comprehensively searched to identify relevant articles. The following inclusion criteria were applied: (1) the sample of respondents consisted of soccer players irrespective of their age, sex, or level of competition; (2) athletes experienced anterior cruciate ligament injury and underwent ACLR; (3) outcomes estimated referred to the RTP, RTP at the preinjury level of competition, RTP time, performance, and career duration of soccer players; (4) studies were written in the English language. The methodological quality of the research was evaluated using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

Databases searched yielded a total of 694 studies, of which 17 fulfilled the eligibility criteria and were included in the final analysis. These included 3657 soccer players, 2845 males and 812 females, who underwent ACLR and most commonly competed at the elite, national, amateur, and recreational levels. The results obtained indicated that 72% of soccer players successfully RTP and 53% RTP at the preinjury level of participation after ACLR. In addition, recent evidence provided in this literature review demonstrated that mean RTP time was 264 days or 8.7 months. Moreover, the majority of the studies unambiguously suggested that performance related to statistical aspects noticeably deteriorated compared with both the preinjury period and noninjured athletes. The mean career length of soccer players following ACL surgery was approximately between 4 and 5 years.

CONCLUSION

Although a high percentage of athletes RTP after a relatively short period of absence from the sports field compared with other sports closely related to soccer, ACLR negatively impacts soccer players' performance and career duration.

Career Length After Surgically Treated ACL Plus Collateral Ligament Injury in Elite Athletes

BACKGROUND

Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes.

PURPOSE

To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level.

RESULTS

A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups.

CONCLUSION

Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Anterior Cruciate Ligament Ruptures in Russian Premier League Soccer Players During the 2010 to 2021/2022 Competitive Seasons: The Epidemiology and Details of Return to Sports

Background

There are limited data on the epidemiology of anterior cruciate ligament (ACL) ruptures in elite adult soccer players, especially in the Russian Premier League (RPL). There is an increased risk of injury due to a combination of additional risk factors such as playing in extremely high and low temperatures, frequent long flights, and regular play on natural and artificial surfaces.

Purpose

To study the epidemiology of ACL ruptures and determine the patterns associated with their occurrence in RPL soccer players.

Study Design

Descriptive epidemiology study.

Methods

All ACL ruptures requiring surgery sustained by players competing in the RPL across 12 competitive seasons between 2010 and 2022 were analyzed. All required data were collected from media analysis and confirmed by club doctors.

Results

A total of 85 players sustained 100 injuries during 12 competitive seasons. A total of 96.5% of players returned to competitive play. The injury incidence in RPL and during participation of RPL teams in European Cups were 0.4760 and 0.5622 per 1000 playing hours, respectively. When analyzing the outcomes of the primary ACL surgery (a total of 76 operations), the following data were obtained: in 11 cases (14.5%), there was a reinjury on the ipsilateral knee joint and in 4 cases (5.3%) on the contralateral knee joint. The mean return-to-play time after all operations was 284 ± 116 days. The time of return to play after primary reconstruction was 289 ± 136 days, 278 ± 91 days after reconstruction on the contralateral knee and 271 ± 51.5 days after the first ACL revision reconstruction on the ipsilateral knee joints.

Conclusion

RPL ACL injury epidemiology is similar to that in the other leagues from around the world, although there are factors that can potentially influence the number of these injuries.

The Role of Virtual Reality in the Management of Football Injuries

Injuries represent a serious concern for football players, with a significant loss in terms of sport participation and long periods of rehabilitation. According to the 2019/20 UEFA Élite Club Injury Report, the average incidence of injuries during training is 2.8 per 1000 h of training, with an average absence from training of 20 days. In addition, injured athletes are 4 to 7 times more likely to relapse than uninjured athletes. High workloads and reduced recovery periods represent two of the most important modifiable risk factors. In this context, prevention and an adequate rehabilitation protocol are vital in managing injuries, reducing their incidence, and improving the return to competition. In recent years, technological development has provided new tools in rehabilitation, and Virtual reality (VR) has shown interesting results in treating neurologic and orthopedic pathologies. Virtual Reality (VR) technology finds application in the sports industry as a tool to examine athletes' technical movements. The primary objective is to detect the biomechanical risk factors associated with anterior cruciate ligament injury. Additionally, VR can be used to train athletes in field-specific techniques and create safe and controlled therapeutic environments for post-injury recovery. Moreover, VR offers a customizable approach to treatment based on individual player data. It can be employed for both prevention and rehabilitation, tailoring the rehabilitation and training protocols according to the athletes' specific needs.

Effects of transcranial direct current stimulation and sensorimotor training in anterior cruciate ligament patients: a sham-controlled pilot study

BACKGROUND

Studies showed changes in the central nervous system in patients who sustained an anterior cruciate ligament tear. There is a lack of evidence regarding the effectiveness of transcranial direct-current stimulation in such patients.

METHODS

A sham-controlled randomised study. One group of patients (n = 6) underwent 6 weeks of sensorimotor training after an anterior cruciate ligament tear during transcranial direct-current stimulation. The stimulation consisted of 20 minutes (3 sessions/week; 2 weeks) of 2 mA anodal transcranial direct-current stimulation over the primary motor and premotor cortex. The second group (n = 6) received sham stimulation with 6 weeks of sensorimotor training. Centre of pressure deviations in the medio-lateral and anterior-posterior direction and centre of pressure velocity were measured.

RESULTS

The results demonstrated a significant effect of sensorimotor training on the centre of pressure in medio-lateral and anterior-posterior direction (p=0.025) (p=0.03) in the leg in which an anterior cruciate ligament tear occurred. The type of training did not affect the results. Post-hoc tests showed no significant effect of training in the subgroups (p≥0.115).

CONCLUSION

Sensorimotor training led to a decrease in sway of the centre of pressure in patients who sustained an anterior cruciate ligament tear, but the addition of anodal transcranial direct-current stimulation placed over the primary motor cortex did not potentiate the adaptive responses of the sensorimotor training.

Either Autonomy Support or Enhanced Expectancies Delivered Via Virtual-Reality Benefits Frontal-Plane Single-Leg Squatting Kinematics

Our purpose in this study was to determine the effects of a virtual reality intervention delivering specific motivational motor learning manipulations of either autonomy support (AS) or enhanced expectancies (EE) on frontal plane single-leg squatting kinematics. We allocated 45 participants (21 male, 24 female) demonstrating knee, hip, and trunk frontal plane mechanics associated with elevated anterior cruciate ligament injury risk to one of three groups (control, AS, or EE). Participants mimicked an avatar performing five sets of eight repetitions of exemplary single-leg squats. AS participants were given the added option of choosing the color of their avatar. EE participants received real-time biofeedback in the form of green highlights on the avatar that remained on as long as the participant maintained pre-determined 'safe' frontal plane mechanics. We measured peak frontal plane knee, hip, and trunk angles before (baseline) and immediately following (post) the intervention. The control group demonstrated greater increases in knee abduction angle (Δ = +2.3°) than did the AS (Δ = +0.1°) and EE groups (Δ = -0.4°) (p = .003; η2p = .28). All groups demonstrated increased peak hip adduction (p = .01, ηp2 = .18) (control Δ = +1.5°; AS Δ = +3.2°; EE Δ = +0.7°). Hip adduction worsened in all groups. AS and EE motivation strategies appeared to mitigate maladaptive frontal plane knee mechanics.

[Injury prevention in football : A challenge for team doctors and coaching team]

High injury rates and long injury-related downtimes demonstrate the need for effective and differentiated injury prevention strategies in football. Preventive measures should take place in various fields and should not be reduced to training programmes or medical approaches. The so-called "Big 6 of injury prevention" provide an overview of the key areas that should be addressed. In modern sports medicine, it should be a matter of course that the team doctor already participates in the primary prevention strategies and does not only get involved in the post-traumatic treatment. Similarly, a decision on a player's return to play after an injury should not be based solely on the medical assessment of the team doctor. Good communication and interdisciplinary cooperation, therefore, form the basis for successful prevention.

Anterior Cruciate Ligament Return to Sport after Injury Scale (ACL-RSI) Scores over Time After Anterior Cruciate Ligament Reconstruction: A Systematic Review with Meta-analysis

BACKGROUND

Psychological readiness is an important consideration for athletes and clinicians when making return to sport decisions following anterior cruciate ligament reconstruction (ACLR). To improve our understanding of the extent of deficits in psychological readiness, a systematic review is necessary.

OBJECTIVE

To investigate psychological readiness (measured via the Anterior Cruciate Ligament-Return to Sport after Injury scale (ACL-RSI)) over time after ACL tear and understand if time between injury and surgery, age, and sex are associated with ACL-RSI scores.

METHODS

Seven databases were searched from the earliest date available to March 22, 2022. Articles reporting ACL-RSI scores after ACL tear were included. Risk of bias was assessed using the ROBINS-I, RoB-2, and RoBANS tools based on the study design. Evidence certainty was assessed for each analysis. Random-effects meta-analyses pooled ACL-RSI scores, stratified by time post-injury and based on treatment approach (i.e., early ACLR, delayed ACLR, and unclear approach).

RESULTS

A total of 83 studies were included in this review (78% high risk of bias). Evidence certainty was 'weak' or 'limited' for all analyses. Overall, ACL-RSI scores were higher at 3 to 6 months post-ACLR (mean = 61.5 [95% confidence interval (CI) 58.6, 64.4], I2 = 94%) compared to pre-ACLR (mean = 44.4 [95% CI 38.2, 50.7], I2 = 98%), remained relatively stable, until they reached the highest point 2 to 5 years after ACLR (mean = 70.7 [95% CI 63.0, 78.5], I2 = 98%). Meta-regression suggests shorter time from injury to surgery, male sex, and older age were associated with higher ACL-RSI scores only 3 to 6 months post-ACLR (heterogeneity explained R2 = 47.6%), and this reduced 1-2 years after ACLR (heterogeneity explained R2 = 27.0%).

CONCLUSION

Psychological readiness to return to sport appears to improve early after ACL injury, with little subsequent improvement until ≥ 2-years after ACLR. Longer time from injury to surgery, female sex and older age might be negatively related to ACL-RSI scores 12-24 months after ACLR. Due to the weak evidence quality rating and the considerable importance of psychological readiness for long-term outcomes after ACL injury, there is an urgent need for well-designed studies that maximize internal validity and identify additional prognostic factors for psychological readiness at times critical for return to sport decisions.

REGISTRATION

Open Science Framework (OSF), https://osf.io/2tezs/ .

Patient-Centred Care in ACL Reconstruction and Meniscus Repair and Rehabilitation

There is an inherent risk for anyone who plays competitive sport or engages in strenuous activity that at some juncture they may suffer an injury which will require surgery. This is a situation in which prevention is not always a viable substitute for cure. Beyond the immediate pain and distress that injuries can cause and the difficult decisions that may have to be made with regards to surgery, there is also a wide range of physical and psychological challenges that patients will face and have to overcome during their recovery journeys. This chapter considers the case of an experienced expatriate amateur sports player in China who ruptured his ACL and punctured his meniscus playing football. It explores his experience of the process he then went through as he navigated diagnosis, surgery, and subsequent recovery, considering his rehabilitation motivation and the social identity impact he encountered. It also takes into account patient autonomy, shared decision making, and engagement in medical practice.

Spatiotemporal lower-limb asymmetries during stair descent in athletes following anterior cruciate ligament reconstruction

PURPOSE

This study evaluated motor control recovery at different times following anterior cruciate ligament reconstruction (ACLR) by investigating lower-limb spatiotemporal symmetry during stair descent performances.

METHODS

We used a cross-sectional design to compare asymptomatic athletes (Controls, n = 18) with a group of people with ACLR (n = 49) divided into three time-from-ACLR subgroups (Early: <6 months, n = 17; Mid: 6-18 months, n = 16; Late: ≥18 months, n = 16). We evaluated: "temporal symmetry" during the stance subphases (single-support, first and second double-support) and "spatial symmetry" for hip-knee-ankle intra-joint angular displacements during the stance phase using a dissimilarity index applied on superimposed 3D phase plots.

RESULTS

We found significant between-group differences in temporal variables (p ≤ 0.001). Compared to Controls, both Early and Mid (p ≤ 0.05) showed asymmetry in the first double-support time (longer for their injured vs. non-injured leg), while Early generally also showed longer durations in all other phases, regardless of stepping leg. No statistically significant differences were found for spatial intra-joint symmetry between groups.

CONCLUSION

Temporal but not spatial asymmetry in stair descent is often present early after ACLR; it may remain for up to 18 months and may underlie subtle intra- and inter-joint compensations. Spatial asymmetry may need further exploration.

The Effect of Primary ACL Reconstruction on Career Longevity in English Premier League and Championship Soccer Players Compared With Uninjured Controls: A Matched Cohort Analysis

BACKGROUND

Because of the multitude of variables that affect the retirement decisions of professional soccer players, it has proven difficult to isolate the effect of undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) on career longevity.

PURPOSE

To compare the career longevity of professional soccer players after a primary ACLR with that of an uninjured matched control cohort.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective review of a consecutive series of primary ACLR was performed between 2008 and 2018 in professional male soccer players from the senior author's practice. Each athlete with ACLR was matched to 3 control athletes who had not undergone ACLR according to age, league, playing position, and preinjury game appearances/minutes played. Player career statistics-including league, game appearances, and game minutes-were compiled for each year until retirement or July 1, 2022.

RESULTS

A total of 82 soccer players in the English Premier League or Championship at the time of their primary ACLR were matched to 246 control athletes. The mean career length after ACLR was 6 ± 2.6 years, while that of the matched control athletes was 7.6 ± 2.8 years (P < .001). After primary ACLR, an athlete had a 2 times greater chance of retirement compared with the matched control athlete (hazard ratio, 2.19; P < .001). At 5 years after ACLR, 16% of athletes had retired from professional soccer, while 8.5% of the matched cohort were retired (P = .060). By 10 years, 72% of the ACLR cohort had retired compared with 43% of the matched cohort (P < .001). Forwards were more likely to have shortened careers compared with goalkeepers (P = .021); however, no significant differences were observed between midfielders, defenders, and forwards. Within the ACLR cohort, a contralateral ACL tear during the athlete's career caused a 2.30 times (P = .022) increased chance of retirement compared with athletes with only 1 ACL tear during their career. Mechanism of injury, meniscal pathology, graft rerupture, and chondral lesions did not affect career length.

CONCLUSION

Professional male soccer players who underwent ACLR had decreased career length by approximately 1.6 years compared with a matched player cohort.

Jumping into recovery: A systematic review and meta-analysis of discriminatory and responsive force plate parameters in individuals following anterior cruciate ligament reconstruction during countermovement and drop jumps

Purpose

Comprehensive understanding of force plate parameters distinguishing individuals postprimary anterior cruciate ligament reconstruction (ACLR) from healthy controls during countermovement jumps (CMJ) and/or drop jumps (DJ) is lacking. This review addresses this gap by identifying discriminative force plate parameters and examining changes over time in individuals post-ACLR during CMJ and/or DJ.

Methods

We conducted a systematic review and meta analyses following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Nine databases were searched from inception to March 2022. We included cross-sectional papers comparing post-ACLR with healthy controls or longitudinal studies of individuals at least 6 months postprimary ACLR while performing CMJ and/or DJ on force plates. The methodological quality was appraised using the Modified Downs and Black Checklist.

Results

Thirty-three studies including 1185 (50.38%) participants post-ACLR, and 1167 (49.62%) healthy controls, were included. Data were categorised into single-leg CMJ, double-leg CMJ, single-leg DJ, and double-leg DJ. Jump height was reduced in both single (mean difference [MD] = -3.13; p < 0.01; 95% confidence interval [CI]: [-4.12, -2.15]) and double-leg (MD = -4.24; p < 0.01; 95% CI: [-5.14, -3.34]) CMJs amongst individuals with ACLR. Similarly, concentric impulse and eccentric/concentric impulse asymmetry could distinguish between ACLR (MD = 3.42; p < 0.01; 95% CI: [2.19, 4.64]) and non-ACLR (MD = 5.82; p < 0.01; 95% CI: [4.80, 6.80]) individuals. In double-leg DJs, peak vertical ground reaction forces were lower in the involved side (MD = -0.10; p = 0.03; 95% CI: [-0.18, -0.01]) but higher in the uninvolved side (MD = 0.15; p < 0.01; 95% CI: [0.10, 0.20]) when compared to controls and demonstrated significant changes between 6 months and 3 years post-ACLR.

Conclusion

This study identified discriminative kinetic parameters when comparing individuals with and without ACLR and also monitored neuromuscular function post-ACLR. Due to heterogeneity, a combination of parameters may be required to better identify functional deficits post-ACLR.

Level of Evidence

Level III.

The Impact of Injury on Career Progression in Elite Youth Football-Findings at 10 Years

Background: There is a lack of evidence regarding the impact of time loss, match exposure, and age at injury on career progression in elite football. Therefore, the aim of this study was to identify injury characteristics and their influence on career progression in a German youth academy. Methods: During the 2012/2013 season, a prospective cohort study reported 107 time-loss injuries among 130 young athletes from an elite German soccer academy. Individual career progression was analyzed using 10-year data. Results: Injuries and time loss were not associated with career progression (p > 0.05) in the overall cohort. In the U17 and U19 groups, 24% were able to reach the professional level, with injuries significantly decreasing this probability (p = 0.002). Injuries lasting more than 28 days had a negative impact on career progression compared to minor injuries (30% vs. 10%; p = 0.02). Conclusions: Not only the characteristics of injuries, but also their impact on career development, vary with age. In the U17 and U19 age groups, serious injuries resulting in more than 28 days of absence have a negative impact on career progression. It is important to be aware of these effects in order to focus on the prevention of long-term injuries to ensure the optimal development of young athletes.

Better Safe Than Sorry? A Systematic Review with Meta-analysis on Time to Return to Sport After ACL Reconstruction as a Risk Factor for Second ACL Injury

OBJECTIVE: To compare the time to return to sport (RTS) between patients who did and did not suffer a second anterior cruciate ligament (ACL) injury after ACL reconstruction. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: Cochrane Library, Embase, Medline, AMED, and PEDro databases were searched in August 2021 and again in November 2022. STUDY SELECTION CRITERIA: Clinical studies reporting time to RTS after ACL reconstruction and second ACL injury were eligible. DATA SYNTHESIS: We pooled continuous data (time [months] and proportions [%]), with random-effects meta-analyses. Pooled estimates were summarized in forest plots. A qualitative data synthesis was also performed. RESULTS: Twenty-one studies were included in the meta-analysis and 33 in the qualitative synthesis. Pooled incidence of second ACL injury was 16.9% (95% confidence interval [CI]: 12.8, 21.6). Patients who suffered a second ACL injury returned to sport significantly earlier (25 days; 95% CI: 9.5, 40.4) than those who did not suffer another injury. There was no difference in time to RTS for professional athletes who suffered a second ACL injury and those who did not. The certainty of evidence was very low. CONCLUSION: There was very low-certainty evidence that patients who suffered a second ACL injury had returned to sport 25 days earlier than patients who did not have another injury. For professional athletes, there was no difference in time to RTS between athletes who suffered a second ACL injury and athletes who did not. J Orthop Sports Phys Ther 2024;54(3):1-15. Epub 30 November 2023. doi:10.2519/jospt.2023.11977.

Anterior cruciate ligament injuries in elite ski jumping reliably allow return to competition but severely affect future top performance

PURPOSE

In recent years, anterior cruciate ligament (ACL) injuries have been frequently observed in ski jumping. However, available data in this discipline are very scarce. Therefore, the purpose of this study was to investigate whether an ACL injury in elite-level ski jumping limits the performance level after ACL reconstruction (ACLR).

METHODS

Both male and female elite-level ski jumpers from five national A-teams who suffered an ACL injury were identified retrospectively by searching available media reports and Fédération Internationale de Ski (FIS) database. World Cup (WC) results and time-out-of-competition before ACL injury and after ACLR were compared. Only athletes who suffered the injury during or after the 2009-2010 season and who participated in at least one WC competition before the injury were included in this study. The level of athletes' performance from two full seasons before until three seasons after the injury was compared.

RESULTS

Eighteen elite-level ski jumpers (11 males/seven females) were eligible for the study. All male and four female athletes returned to professional competition after ACLR. One female athlete ended her career due to prolonged recovery and two have not yet recovered due to a recent injury. The mean return-to-competition (RTC) time was 14.6 months in males and 13.5 months in females. The mean WC placement decreased after the ACL injury: two seasons before injury the mean position was 17.9 ± 11.0 (n = 12), one season before it was 22.4 ± 12.8 (n = 15). After recovery, the mean placement in seasons 1-3 was: 26.4 ± 8.9 (n = 7), 25.7 ± 10.3 (n = 13), 33.6 ± 12.2 (n = 10) (p = 0.008). Among the athletes returning to competition, only six males and three females reached their preinjury level and only one male and one female (compared to seven males and three females preinjury) reached an individual top-3 placement after ACLR, accounting for less than 10% of podiums compared to preinjury.

CONCLUSION

Only 60% of the professional ski jumpers reached the preinjury level and less than 15% reached a top-3 placement after the ACL injury. These results support the fact that ACL tear during a ski jumping career may be a significant factor limiting high-level performance. In terms of clinical relevance, the findings implicate the need to analyse the reasons of these very low rates of return to elite-level performance, to analyse ACL injury and RTC rates at lower levels of performance and to develop specific prevention strategies in order to reduce the number of ACL injuries in this sport.

LEVEL OF EVIDENCE

Level IV.

Neurocognitive Errors and Noncontact Anterior Cruciate Ligament Injuries in Professional Male Soccer Players

CONTEXT

Evidence is emerging that core neurocognitive functions such as working memory and inhibitory control (ie, motor-response and attentional inhibition) are linked to the anterior cruciate ligament (ACL) injury risk. Research has been conducted in laboratory settings, but the contribution of neurocognition to actual ACL injuries under real-world conditions is unknown.

OBJECTIVE

To describe the possible neurocognitive errors involved in noncontact ACL injury mechanisms.

DESIGN

Case series.

SETTING

Soccer matches.

PATIENTS OR OTHER PARTICIPANTS

A total of 47 professional male soccer players.

MAIN OUTCOME MEASURE(S)

Three independent reviewers evaluated 47 videos of players sustaining noncontact ACL injuries. Neurocognitive errors in inhibitory control were operationalized as follows: (1) motor-response inhibition was scored when a player demonstrated poor decision-making and approached the opponent with high speed that reduced the ability to stop or change the intended action and (2) an attentional error was scored when a player shifted his selective attention away from the relevant task to irrelevant stimuli.

RESULTS

Of 47 noncontact ACL injuries, 26 (55%) were related to a pressing-type injury, 19 (73%) of which involved a deceiving action made by the opponent, suggesting poor inhibitory control of the defender. Of the remaining 21 noncontact ACL injuries (45%), 16 (76%) could be attributed to attentional errors. Agreement among the 3 raters was very good for all items except poor decision-making, which showed fair to good agreement (Fleiss κ = 0.71). Interrater reliability was excellent (intraclass correlation coefficient = 0.99-1.00).

CONCLUSIONS

Errors in motor-response inhibitory control and attentional inhibition were common during noncontact ACL injury events in professional male soccer players. The interrater agreement in detecting neurocognitive errors in general was very good.

Functional outcomes of accelerated rehabilitation protocol for anterior cruciate ligament reconstruction in amateur athletes: a randomized clinical trial

BACKGROUND

Anterior cruciate ligament (ACL) rupture is the most common knee injury among athletes, and can result in long-term complications and career-ending conditions for sportspeople. There is no consensus in the literature on the effectiveness of rehabilitation after ACL reconstruction, or the best protocol to follow for functional outcome improvement.

OBJECTIVE

To determine the impact of an accelerated rehabilitation protocol on knee functional outcomes in amateur athletes with anterior cruciate ligament reconstruction (ACLR).

DESIGN

Two-arm, parallel-group randomized comparative design.

PATIENTS

A total of 100 amateur male athletes (mean age 22.01 ± 1.79 years) with ACLR were randomly divided into experimental and control groups (n = 50/group).

METHODS

An accelerated rehabilitation protocol and a conventional rehabilitation protocol were used for the experimental group. In contrast, only the conventional rehabilitation protocol was used for the control group. The rehabilitation was delivered in 5 weekly sessions for 22 weeks. The primary outcome measure, knee pain, was measured using a visual analogue scale (VAS). Extensive test batteries, for hop tests, Knee Injury and Osteoarthritis Outcome Score (KOOS), and knee effusion, were measured, aiming to add more objective criteria to determine functional performance.

RESULTS

Both groups (n = 50/group) were well-matched (p = 0.816), with insignificant differences in their demographic characteristics (p > 0.05). A multivariate analysis of variance (MANOVA) test showed no significant difference between the 2 groups (p = 0.781) at baseline. A 2-way MANOVA (2 × 2 MANOVA) of within- and between-group variations indicated overall significant treatment, time, and treatment × time interaction effects (p < 0.001) in favour of the accelerated rehabilitation group.

CONCLUSION

The accelerated rehabilitation protocol was more effective in improving functional outcomes than a conventional rehabilitation protocol in amateur athletes with ACLR.

Variables Associated With Knee Valgus in Male Professional Soccer Players During a Single-Leg Vertical Landing Task

Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was .43 during the landing phase (P = .04) and with peak hip internal rotation was -.68 (P < .001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r = .40, P = .05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test.

Optimising the Early-Stage Rehabilitation Process Post-ACL Reconstruction

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria).

Determinants of Performance in Professional Soccer Players at 2 and 5 Years After ACL Reconstruction

BACKGROUND

A number of studies have investigated return to play after anterior cruciate ligament reconstruction (ACLR) in professional soccer players, but it is unclear which factors are associated with a return to the preinjury performance and ability to play over time.

PURPOSE

To identify factors that contribute to a professional soccer player's return to preinjury performance after ACLR, as well as to report their playing performance at 2 and 5 years after ACLR compared with their preinjury performance.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

A consecutive cohort of professional soccer players undergoing primary ACLR were analyzed between 2005 and 2019. A minimum 2-year follow-up was required. The effect of patient, surgical, and postoperative factors on performance rates, defined as a combination of league level and playing time, was evaluated with univariate and multivariate logistic regression models.

RESULTS

A total of 200 male professional soccer players were included. When combining league level and playing time, 30% of athletes returned to their preinjury performance at 2 years and 22% at 5 years. However, 53% of athletes returned to their preinjury performance for at least 1 season by year 5. At 2 years, a chondral lesion of grade 3 or 4 decreased the odds of return to preinjury performance (odds ratio [OR], 0.37; P = .010). Athletes receiving an ACLR with the addition of a lateral extra-articular tenodesis procedure were 2.42 times more likely to return to preinjury performance at 2 years than athletes with ACLR alone (P = .004). By 5 years after ACLR, athletes aged ≥25 years at the time of reconstruction were 3 times less likely to be performing at their preinjury performance (OR, 0.32; P < .001), and those with a grade ≥3 chondral lesion were >2 times less likely to be performing at their preinjury performance (OR, 0.43; P = .033).

CONCLUSION

The presence of >50% thickness chondral pathology, ACLR without lateral extra-articular tenodesis, and age >25 years at the time of surgery were all significant risk factors of worse performance rates after ACLR. Significant decreases in performance rates were noted at 2 and 5 years postoperatively.

A comparison between physical therapy clinics with high and low rehabilitation volumes of patients with ACL reconstruction

BACKGROUND

Treatment volume can impact outcomes after surgical procedures of the knee between surgeons with high- and low-patient-volumes. However, the difference between physical therapeutic clinics with high- and low-volumes has not been widely researched. This registry study aims to investigate how patient volume affects knee function outcomes after anterior cruciate ligament (ACL) reconstruction at physical therapy (PT) clinics in terms of odds for a second ACL injury, return to pre-injury level of activity, perceived knee function, and recovery of strength and hop performance.

METHOD

Data were extracted from the Project ACL, a local rehabilitation registry. High- and low-volume clinics were defined based on the number of patients who attended different clinics. High-volume clinics were defined as those with > 100 patient registrations in Project ACL during the study period while low-volume clinics were those with ≤ 100 patient registrations. High- and low-volume clinics were compared, based on muscle function and patient-reported outcomes across 4 follow-ups, 2-, 4-, 8-, and 12 months, during the first year after ACL reconstruction, and odds of second ACL injury up to 2 years after ACL reconstruction.

RESULT

Of the 115 rehabilitation clinics included, 111 were classified as low-volume clinics and included 733 patients, and 4 as high-volume clinics which included 1221 patients. There were 31 (1.6%) second ACL injuries to the ipsilateral or contralateral side within the first 12 months and 68 (4.0%) within 2 years. No difference in the incidence of a second ACL injury, within 12 months follow-up odds ratio (OR) 0.95 [95% CI 0.46-1.97] or within 2 years follow-up OR 1.13 [95% CI 0.68-1.88], was found between high- and low-volume clinics. There were early (2 months) and non-clinically relevant differences in patient-reported outcomes (PROs) and physical activity levels early after ACL reconstruction in favor of high-volume clinics. One year after ACL reconstruction, no differences were observed between high- and low-volume clinics in terms of PROs, muscle function, and return to pre-injury level of activity.

CONCLUSION

No clinically relevant difference in the incidence of secondary ACL injuries in patients who underwent rehabilitation after ACL reconstruction at high- or low-volume physical therapist clinics was found. In addition, no clinically relevant differences in outcomes were found during the first year in terms of patient-reported outcomes, recovery of muscle function, or return to pre-injury level of activity.

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.

The impact of a multicomponent training program on physical fitness and joint injuries in Spanish male professional soccer players

This study aimed to assess the effects of a multicomponent training program (ProSAS) on selected measures of physical fitness and joint injuries in Spanish male professional soccer players. Twenty-six professional soccer players (age: 25.2 ± 3.1 years) were randomly assigned to either the experimental (EG; n = 16) or control group (CG; n = 10). Y-balance test (YBT), Single leg countermovement jump (SLCMJ), Single leg hop for distance test (SLH), Side-hop test (SH), Speedy jump test (SpJ), Agility T-test (TT) and Lower extremity functional test (LEFT) were performed before and after an 8-weeks training period. Additionally, any joint injury occurring during the intervention period were recorded. Significant improvements in the EG in all tests (p = 0.001 to p = 0.014), except for SLCMJ (p = 0.632) with the dominant leg were observed. CG displayed decreases in SLCMJ with the non-dominant leg (p = 0.014), SH for both legs (p = 0.001 to p = 0.050), TT (p = 0.005), and LEFT (p = 0.001). Inter-groups differences revealed better results for the EG in all variables (p = 0.001 to p = 0.008) except from SLCMJd (p = 0.555). Moreover, the EG exhibited lower joint injury incidence and burden compared to the CG (p < 0.05). These findings suggest that the ProSAS is an effective multicomponent program to improve variables related to risk of joint injuries, and consequently, to reduce the incidence and burden of these injuries in professional soccer players.

Self-reported knee function and activity level are reduced after primary or additional anterior cruciate ligament injury in female football players: a five-year follow-up study

BACKGROUND

Playing football involves a high risk of anterior cruciate ligament (ACL) injuries and these may affect knee function and activity level.

OBJECTIVES

To measure changes in self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players with or without an ACL-reconstructed knee.

METHODS

Female football players, age 19.9 (SD 2.6) years, with either a primary ACL-reconstruction 1.6 (SD 0.7) years after ACL-reconstruction (n = 186) or no ACL injury (n = 113) were followed prospectively for five years. Self-reported data collected at baseline and follow-up included knee function (International Knee Documentation Committee Subjective Knee Form [IKDC-SKF]), activity level (Tegner Activity Scale), and satisfaction with knee function (Likert scale 1=happy; 7=unhappy) and activity level (1-10 scale). Information on any new ACL injury during the follow-up period was collected.

RESULTS

Players with ACL-reconstruction at baseline who either did (n = 56) or did not (n = 130) sustain an additional ACL injury, and players with no injury at baseline who remained injury free (n = 101) had a lower Tegner score at follow-up. Players with additional ACL injury had lower IKDC-SKF score (mean difference: -11.4, 95% CI: -16.0, -6.7), and satisfaction with activity level (mean difference: -1.5, 95% CI: -2.3, -0.7) at follow-up. Players with no additional ACL injury had higher satisfaction with knee function (mean difference: 0.6, 95% CI: 0.3, 0.9) at follow-up. Players with no ACL injury had lower satisfaction with activity level (mean difference: -0.7, 95% CI: -1.1, -0.3) at follow-up. Players with additional ACL injury had larger decreases in all variables measured compared to the two other groups.

CONCLUSION

Primary, and even more so additional, ACL injuries decreased self-reported knee function, activity level, and satisfaction with knee function and activity level in female football players.