Incidence, Common Pathogens, and Risk Factors for Infection after Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review

We sought to assess the current literature to present a comprehensive summary of the incidence, common pathogens, and risk factors for infection after anterior cruciate ligament (ACL) reconstruction. PubMed, CINAHL, EMBASE, and Scopus databases were searched for relevant studies reporting on infection after ACL reconstruction. Two reviewers independently screened the extracted studies for adherence to inclusion and exclusion criteria. Studies were selected if they reported on the incidence of infection, pathogens cultured from infected knees, or risk factors for infection after primary ACL reconstruction. Exclusion criteria consisted of studies with fewer than 100 patients or studies that included revision ACL reconstruction. Fifty studies met the inclusion and exclusion criteria, reporting on a total of 316,214 ACL reconstructions. Included studies evaluated between 123 and 104,255 patients. The overall incidence of infection was 0.60% (0.15-2.44%). The most common pathogens were Staphylococcus aureus, S. epidermidis, and coagulase-negative Staphylococci. Five studies reported that the use of hamstring autograft was a statistically significant risk factor for infection after ACL reconstruction, thus making hamstring autograft the most commonly reported risk factor. Other reported risk factors included male sex, use of immuno-suppressive medications or intraarticular steroid injections, prior knee surgery, and diabetes. Systematic review of the literature revealed that infection after ACL reconstruction remains an infrequent event with an incidence of 0.60% (0.15-2.44%). Furthermore, the most common pathogens are from the Staphylococcus genus of bacteria, comprising 84% of all culture-positive infections. Multiple risk factors have been reported for ACL reconstruction; however, statistical significance varied across studies. Together, these findings may help guide physicians in the prevention and treatment of infection after ACL reconstruction.

Trends in Pediatric Anterior Cruciate Ligament Reconstruction in Australia: An Analysis of Australian Medicare Benefits Schedule Database From 2001 to 2020

BACKGROUND

Anterior cruciate ligament (ACL) injuries are common and increasingly prevalent in the pediatric population. However, there remain sparse epidemiological data on the surgical treatment of these injuries. The objective of this study is to assess the trends in the rate of pediatric ACL reconstruction in Australia over the past 2 decades.

METHODS

The incidence of ACL reconstruction from 2001 to 2020 in patients 5 to 14 years of age was analyzed using the Australian Medicare Benefits Schedule (MBS) database. Data were stratified by sex and year. An offset term was introduced using population data from the Australian Bureau of Statistics to account for population changes over the study period.

RESULTS

A total of 3719 reconstructions for the management of pediatric ACL injuries were performed in Australia under the MBS in the 20-year period from 2001 to 2020. There was a statistically significant annual increase in the total volume and per capita volume of pediatric ACL reconstructions performed across the study period ( P <0.0001). There was a significant increase in the rate of both male and female reconstructions ( P <0.0001), with a greater proportion of reconstructions performed on males (n=2073, 56%) than females (n=1646, 44%). In 2020, the rate of pediatric ACL reconstructions decreased to a level last seen in 2015, likely due to the effects of COVID-19.

CONCLUSIONS

The incidence of ACL reconstruction in skeletally immature patients has increased in Australia over the 20-year study period. This increase is in keeping with evidence suggesting poor outcomes with nonoperative or delayed operative management.

Risk factors of knee reinjury after anterior cruciate ligament reconstruction

PURPOSE

This study aimed to investigate whether the return to level I sports, concomitant injuries, foot-related problems, and other factors would increase the risk of knee reinjury after anterior cruciate ligament reconstruction (ACLR).

METHODS

This study used a prospective cohort study design. Online enrolment from August 2018 to January 2019 in ACL Community Indonesia recruited 148 patients who had undergone ACLR less than one month prior to injury. Knee injury occurrence after ACLR was diagnosed through a physical examination and positive MRI or arthroscopic findings.

RESULTS

During the study, 55 knee reinjuries occurred. The proportional hazards model analysis revealed that the risk of knee reinjury at 12 and 24 months for patients who returned to level I sports (hazards ratio (HR)=3.17 and HR=3.90, respectively) was significantly higher than that of the patients who did not return to sports and that the risk for those who returned to level II/III sports did not significantly increase at 12 or 24 months. Patients with concomitant meniscus injury had a significantly higher risk of knee reinjury at 12 and 24 months (HR=3.33 and HR=2.25, respectively) than those without, and the risk of knee reinjury for patients with concomitant posterior cruciate ligament injury was significantly higher at 12 months (HR=3.05) but not at 24 months. Fewer knee symptoms after ACLR were significantly associated with a lower risk of knee reinjury (HR=0.98) at 12 and 24 months.

CONCLUSIONS

The return to level I sports, concomitant meniscus and posterior cruciate ligament injury, and knee symptoms after ACLR may increase the risk of knee reinjury for post-ACLR patients.

What exercise programme is the most appropriate to mitigate anterior cruciate ligament injury risk in football (soccer) players? A systematic review and network meta-analysis

OBJECTIVES

To examine the effectiveness of different exercise-based interventions to mitigate the risk of anterior cruciate ligament injury in football players, and to determine which is the most appropriate for them, specifically for female football players.

DESIGN

Four databases were accessed in July 2023 using the keywords football, soccer, athletic injuries, anterior cruciate ligament, knee injuries, injury prevention, exercise-based programme, and risk factor.

METHODS

Randomised controlled trials that evaluated any exercise-based injury prevention intervention compared with a control group on the prevention of anterior cruciate ligament injury in football players were included.

RESULTS

Eleven studies were included. Data were presented as logarithm hazard ratio, credible intervals and standard deviation. FIFA 11+ was the most effective in reducing anterior cruciate ligament injury risk in football players (logarithm hazard ratio = -1.23 [95% credible intervals: -2.20, -0.35]; SD = 0.47), followed by the Knäkontroll programme (logarithm hazard ratio = -0.76 [95% credible intervals: -1.60, -0.03]; standard deviation = 0.42). For females, only Knäkontroll had a significant impact on reducing the risk of anterior cruciate ligament injury (logarithm hazard ratio = -0.62 [95% credible intervals: -1.71, 0.62]; standard deviation = 0.58).

CONCLUSIONS

Our results support the use of FIFA 11+ and Knäkontroll to mitigate injury incidence at overall level. However, the effectiveness of these interventions changed when adjusting for females. Knäkontroll is postulated as the programme with the greatest preventive nature, although these results should be interpreted with caution due to the lack of the sample.

The anteromedial retinaculum in ACL-injured knees: An overlooked injury?

PURPOSE

The purpose of this study was to retrospectively analyse the pattern of injury to the medial knee structures in anterior cruciate ligament (ACL) injured patients. It was hypothesised that anteromedial injuries would be more common than posteromedial lesions.

METHODS

One hundred and twenty subjects aged 18-25 years with a primary ACL injury were included. Patients were excluded if the time between injury and magnetic resonance imaging (MRI) was more than 28 days or if a knee dislocation or fracture was present. The MRIs were analysed with particular emphasis on injuries to the medial knee structures, menisci and bone bruise patterns. Injuries to the ligaments and anteromedial retinaculum (AMR) were graded according to severity, ranging from periligamentous oedema (grade I), partial fibre disruption of less or more than 50% (grade IIa or IIb) to complete tears (grade III).

RESULTS

AMR injury was seen in 87 subjects (72.5%) on the coronal plane and in 88 (73.3%) on the axial plane, with grade III lesions observed in 27 (22.5%) and 29 knees (24.2%). Injuries to the superficial medial collateral ligament (sMCL), deep MCL (dMCL) and posterior oblique ligament (POL) were detected in 60 patients (50%), 93 patients (77.5%) and 38 patients (31.6%). However, grade III injuries to the POL were observed in only seven knees (5.8%). Medial meniscus injuries were associated with lesions of the sMCL and AMR (p < 0.05), while lateral meniscus injuries were significantly more common in patients with dMCL rupture (p < 0.05).

CONCLUSION

Data from this study suggest that injuries to the AMR are much more common than posteromedial lesions in subjects with ACL injuries.

LEVEL OF EVIDENCE

Level IV.

Lost in transition: Exploring injury risk in academy footballers shifting between the second and first teams

OBJECTIVES

To compare the injury profiles of football players shifting between second and first teams with those of second- and first-team players, and to examine the opinions of shifting players.

DESIGN

Prospective cohort study.

METHODS

170 male players from Athletic Club (second team = 90, shifting = 20, first team = 60) were followed over eight seasons. Injuries and exposure time were recorded following the FIFA consensus, and 18 shifting players answered a seven-item questionnaire on their experience.

RESULTS

35 % shifting players became full-time first-team players, in contrast to only 8 % of second-team players (odds ratio = 6.4, p < 0.01). There were no differences in the overall injury incidence, but the overall burden of injuries was higher in second-team (172 days lost/1000 h) and shifting players (194 days lost/1000 h) compared with first-team players (114 days lost/1000 h, p < 0.01). Shifting players had a higher burden of knee joint/ligament injuries compared with first-team players (137 vs. 18 days lost/1000 h, p < 0.01) and anterior cruciate ligament (ACL) ruptures (122 vs. 10 days lost/1000 h, p < 0.01). There was a trend towards a higher burden of ACL ruptures in shifting players than in second-team players (122 vs. 41 days lost/1000 h, p = 0.07). Shifting players reported constant pressure and better communication with the second-team coaching staff than with the first-team staff.

CONCLUSIONS

The high burden of injuries in shifting players, particularly from ACL ruptures, highlights the need for action. Ensuring high-quality communication between second- and first-team staff remains a key challenge.

Incidence of Convergence Between Distally and Anteriorly Oriented ALL Femoral Tunnels and ACL Femoral Tunnels in Combined ACL and ALL Reconstruction: 3-Dimensional Computed Tomography Analysis of 227 Patients

BACKGROUND

Adjusting the direction of the anterolateral ligament (ALL) femoral tunnel is suggested to avoid tunnel convergence during anterior cruciate ligament (ACL) reconstruction. Yet, there has been no in vivo clinical study reporting the effect of changing the direction of the ALL tunnel on the incidence of convergence with the ACL tunnel.

PURPOSE

To report the incidence of convergence between the ACL femoral tunnel and a distally and anteriorly directed ALL femoral tunnel and to determine a safe distal angle and anterior angle.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 227 patients undergoing concomitant ALL and anatomic single-bundle ACL reconstruction between January 2020 and December 2022 were retrospectively reviewed. The tunnel convergence rate, angular orientation of the tunnels, and distance between tunnels were obtained using postoperative computed tomography. The patients were grouped based on the direction of the ALL tunnel (transverse vs distal anterior) and the presence of tunnel convergence (convergence vs no convergence).

RESULTS

The overall tunnel convergence rate was 53.3% (121/227 patients). Tunnel convergence was observed less frequently in the distal anterior group (33.7%) than in the transverse group (65.2%) (P < .001). The no convergence group showed an ALL tunnel oriented more distally (20.2°± 11.1°) and anteriorly (19.5°± 10.2°) compared with the convergence group (8.7°± 6.5° and 6.9°± 5.3°, respectively) (P = .005 and P = .008, respectively). There were no cases of tunnel convergence for ALL tunnels >24.3° distally and >25.5° anteriorly. There was no difference in the angle of the ACL femoral tunnel between all groups.

CONCLUSION

A distally and anteriorly directed ALL femoral tunnel reduced the incidence of convergence with the ACL femoral tunnel. A distal angle >24.3° and an anterior angle >25.5° of an ALL tunnel are suggested to safely avoid convergence with the ACL tunnel.

UEFA Women's Elite Club Injury Study: a prospective study on 1527 injuries over four consecutive seasons 2018/2019 to 2021/2022 reveals thigh muscle injuries to be most common and ACL injuries most burdensome

OBJECTIVE

Injuries in women's football (soccer) have scarcely been investigated, and no study has been conducted in the highest competitive level involving club teams from different countries. Our aim was to investigate the time-loss injury epidemiology and characteristics among women's elite football players over four seasons.

METHODS

596 players from 15 elite women's teams in Europe were studied prospectively during the 2018/2019 to 2021/2022 seasons (44 team seasons). Medical staff recorded individual player exposure and time-loss injuries. Injury incidence was calculated as the number of injuries per 1000 playing hours and injury burden as the number of days lost per 1000 hours.

RESULTS

1527 injuries were recorded in 463 players with an injury incidence of 6.7 (95% CI 6.4 to 7.0) injuries per 1000 hours and a nearly fourfold higher incidence during match play compared with training (18.4, 95% CI 16.9 to 19.9 vs 4.8, 95% CI 4.5 to 5.1; rate ratio 3.8, 95% CI 3.5 to 4.2). Thigh muscle injuries (hamstrings 12%, 188/1527, and quadriceps 11%, 171/1527) were the most frequent injury, while anterior cruciate ligament (ACL) injury had the highest burden (38.0 days lost per 1000 hours, IQR 29.2-52.1) with median days lost of 292 (IQR 246-334) days. Concussions constituted 3% (47/1527) of all injuries, with more than half of them (55%, 26/47) due to ball-related impact.

CONCLUSION

An elite women's football team can expect approximately 35 time-loss injuries per season. Thigh muscle injury was the most common injury and ACL injury had the highest injury burden.

Incidence of and Risk Factors for Medial Meniscal Lesions at the Time of ACL Reconstruction: An Analysis of 4697 Knees From the SANTI Study Group Database

BACKGROUND

Medial meniscal (MM) lesions (MMLs) are a common finding at the time of anterior cruciate ligament reconstruction (ACLR). It is recognized that evaluation of the posteromedial compartment reduces the rate of missed MML diagnoses.

PURPOSE

To determine the incidence of MMLs in patients undergoing ACLR, when using a standardized arthroscopic approach that included posteromedial compartment evaluation, as well as to determine how the incidence of MMLs changed with increasing time intervals between injury and surgery, and to investigate what risk factors were associated with their presence.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective analysis of prospectively collected data was performed. All patients who underwent primary ACLR between January 2013 and March 2023 were considered for study eligibility. The epidemiology was defined by categorizing and reporting the incidence and categorizing the spectrum of MM tear types. Risk factors associated with MMLs were analyzed using a logistic regression model.

RESULTS

MMLs were identified in 1851 (39.4%) of 4697 consecutive patients undergoing ACLR. The overall incidence of MMLs was 33.1% for the period of 0 to 3 months, 38.7% for the period of 3 to 12 months, and 59.6% for the period of >12 months. The overall incidence of MMLs increased with longer durations of time between injury and surgery, along with significant increases in complex, bucket-handle, ramp, and/or flap lesions. The largest increase in incidence of MMLs was observed for complex MM tear patterns. Risk factors associated with MMLs included time between injury and surgery >3 months (odds ratio [OR], 1.320; 95% CI, 1.155-1.509; P < .0001) and >12 months (OR, 3.052; 95% CI, 2.553-3.649; P < .0001), male sex (OR, 1.501; 95% CI, 1.304-1.729; P < .0001), body mass index (BMI) ≥25 (OR, 1.193; 95% CI, 1.046-1.362; P = .0088), and lateral meniscal lesion (OR, 1.737; 95% CI, 1.519-1.986; P < .0001).

CONCLUSION

Overall, MMLs were identified in 39.4% of 4697 patients undergoing ACLR when posteromedial compartment evaluation was performed in addition to standard anterior viewing. The incidence of MMLs and the complexity of tear types increased significantly with increasing time intervals between the index injury and ACLR. Secondary risk factors associated with an increased incidence of medial meniscal tears include male sex, increased BMI, and lateral meniscal lesions.

'Benched' the effect of the COVID-19 lockdown on injury incidence in sub-elite football in Australia: a retrospective population study using injury insurance records

OBJECTIVES

The primary aim of this study was to compare injury rates pre- and post-COVID-19 lockdown in sub-elite football (soccer) players by analysing the full season and the first month of each season between 2018 and 2020. Secondary aims were to describe the incidence, location and type of injuries and to compare injuries by age group and sex.

DESIGN

Descriptive epidemiological study.

METHODS

A de-identified insurance database was retrospectively coded using the Orchard Sports Injury Classification System. Injury incidence per 1000 hours as well as incidence rate ratios (IRR) with confidence intervals were calculated.

RESULTS

No significant difference was found in the overall incidence rate in 2020 compared with the 2018 and 2019 seasons (IRR, 1.04 [95% CI, 0.96-1.13]; p = 0.294). However, overall injuries increased by 26% (IRR: 1.26 [95% CI 1.07-1.47]; p < 0.005) and joint sprains increased by 45% (IRR: 1.45 [95% CI 1.14-1.84]; p < 0.005) in the first month of 2020 compared with 2018-2019. Between 2018 and 2020, there were 4149 injury insurance claims, with anterior cruciate ligament (ACL) ruptures accounting for 19% of all injuries. When comparing sex, female players had significantly more ankle sprains whilst male players suffered more dental injuries.

CONCLUSIONS

This study adds to a growing body of evidence investigating injury rates post-COVID-19 lockdowns in sport. Sub-elite players appear to be at higher risk of joint injuries within the first month of training following a period of lockdown. Overall, stakeholders involved in sub-elite football should prioritise knee and ankle joint injury prevention.

Does playing surface affect the risk of anterior cruciate ligament injuries in the National Football League? A look at the 2017 - 2021 NFL seasons

BACKGROUND

Anterior cruciate ligament (ACL) injuries are devastating injuries for athletes. Prior studies have shown increased ACL injury rates on non-natural surfaces versus natural grass in several sports. The purpose of this study is to calculate the prevalence of ACL injuries in the NFL on natural versus non-natural surfaces to determine if there is a significant increase on non-natural surfaces.

METHODS

Accessing publicly available data for NFL seasons beginning with the 2017-2018 season through 2021-2022 seasons, all ACL injuries with publicly available data concerning timing and playing surface were recorded and categorized according to playing surface. Practice injuries or those without an identifiable playing surface were excluded. Incidence rates, defined as ACL ruptures per game, were calculated. ACL injuries were recorded for each playing surface, as well as the combined category of non-natural grass surface. Odds ratio was calculated to compare the risk of ACL rupture on non-natural surfaces vs natural grass.

RESULTS

During the 2017-2021 NFL seasons, 173 ACL ruptures were identified with known surfaces. Injury rate for non-natural surfaces was 0.134 compared to 0.097 for grass. Injury rate ratio for non-natural vs natural grass surfaces was 1.211, a 21.1% increased risk of ACL injury in the NFL on non-natural surfaces vs natural grass. OR for non-natural surfaces 1.239 (95% CI 0.900-1.704). Based on these findings there is a trend toward increased risk of ACL injury on non natural grass surfaces, however this did not reach statistical significance.

CONCLUSION

Numerous published studies show trends toward increasing rates of ACL injuries on non-natural playing surfaces vs natural grass. Based on our findings the difference is not statistically significant, however it does trend toward increased risk of ACL injury with non-natural surfaces. Further studies should be performed with larger sample sizes in order to further determine the risk of non-natural surfaces.

Epidemiology of Anterior Cruciate Ligament Tears in National Collegiate Athletic Association Athletes: 2014/2015-2018/2019

PURPOSE

This study aimed to describe the epidemiology of ACL tears in NCAA men's and women's sports.

METHODS

Injury and exposure data collected within the NCAA Injury Surveillance Program from 2014/2015 to 2018/2019 were analyzed. ACL tear frequencies, injury rates (IR), and injury proportions were used to describe injury incidence by sport, event type, injury mechanism, and injury history. Injury rate ratios (IRR) were used to examine differential injury rates, and injury proportion ratios (IPR) were used to examine differential distributions.

RESULTS

A total of 729 ACL tears were reported from 8,474,401 recorded athlete exposures (AE) during the study period (IR = 0.86 per 10,000 AE), and the competition-related ACL tear rate was higher than the practice-related rate (IRR = 5.52, 95% confidence interval [CI] = 4.75-6.39). Among men's sports, the highest overall ACL tear rate was observed in men's football (IR = 1.44 per 10,000 AE), whereas among women's sports, the highest overall rate was observed in women's soccer (IR = 2.60 per 10,000 AE). Among sex-comparable sports, ACL tear rates were higher in women's basketball, softball, and soccer, as compared with their men's counterparts. ACL tears were more prevalently attributed to player contact mechanisms in men's sports than women's sports (IPR = 1.73, 95% CI = 1.37-2.19), but more prevalently attributed to noncontact mechanisms in women's sports than men's sports (IPR = 1.17, 95% CI = 1.01-1.35).

CONCLUSIONS

ACL tear risk in women's sports continues to warrant attention and prevention efforts. Given the differential rates by event type, future research efforts may also evaluate initiatives to reduce competition-related injury burden in NCAA sports.

High Prevalence of Superficial and Deep Medial Collateral Ligament Injuries on Magnetic Resonance Imaging in Patients With Anterior Cruciate Ligament Tears

PURPOSE

To assess the prevalence of and factors associated with medial collateral ligament (MCL) complex injuries on magnetic resonance imaging (MRI) in patients with anterior cruciate ligament (ACL) tears.

METHODS

Data were extracted from the Natural Corollaries and Recovery After ACL Injury (NACOX) multicenter longitudinal cohort study. Between May 2016 and October 2018, patients who presented to 1 of 7 health care clinics across Sweden with an ACL tear sustained no more than 6 weeks earlier and who were aged between 15 and 40 years at the time of injury were invited to participate. All the patients included in this study underwent MRI. The mean time from injury to MRI was 19.6 ± 15.2 days. An orthopaedic surgeon specializing in knee surgery and a musculoskeletal radiologist reviewed all MRI scans. Injuries to the superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament were identified. Stepwise forward multiple binary logistic regression analyses were used to evaluate patient characteristics (age, sex, body mass index, preinjury Tegner activity level, and activity at injury) and injuries on MRI (lateral meniscus [LM] injury, medial meniscus [MM] injury, pivot shift-type bone bruising, medial femoral condyle [MFC] bone bruising, and lateral femoral condyle [LFC] impaction) associated with the presence of MCL complex tears.

RESULTS

In total, 254 patients (48.4% male patients) with a mean age of 25.4 ± 7.1 years were included. The overall prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries was 16.5% (42 of 254) and 24.8% (63 of 254), respectively. No isolated sMCL injuries were found. Posterior oblique ligament injuries were found in 12 patients (4.7%) with MCL (sMCL and dMCL) injuries. An LM injury (odds ratio [OR], 3.94; 95% confidence interval [CI], 1.73-8.94; P = .001) and LFC impaction (OR, 2.37; 95% CI, 1.11-5.07; P = .02) increased the odds of having an MCL injury, whereas an MM injury (OR, 0.26; 95% CI, 0.12-0.59; P = .001) reduced the odds. Isolated dMCL injuries were significantly associated with MFC bone bruising (OR, 4.21; 95% CI, 1.92-9.25; P < .001) and LFC impaction (OR, 3.86; 95% CI, 1.99-7.49; P < .001).

CONCLUSIONS

The overall combined prevalence of MCL (sMCL and dMCL) injuries and isolated dMCL injuries in patients with ACL tears was high (16.5% + 24.8% = 41.3%). The presence of an LM injury and LFC impaction increased the odds of having an MCL injury, whereas the presence of an MM injury reduced the odds. MFC bone bruising and LFC impaction were associated with the presence of isolated dMCL injuries.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Prevalence and Predictors of Concomitant Meniscal and Ligamentous Injuries Associated With ACL Surgery: An Analysis of 20 Years of ACL Reconstruction at a Tertiary Care Children's Hospital

BACKGROUND

There is an increasing rate of procedures being performed for concomitant injuries during anterior cruciate ligament (ACL) surgery. Few studies have examined risk factors for these associated injuries in young patients.

HYPOTHESIS

There are patient-related factors predictive of concomitant knee pathology that differ between age-based cohorts.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Natural language processing was used to extract clinical variables from available notes of patients undergoing ACL surgery between 2000 and 2020 at a single institution (5174 ACL surgeries; mean age, 17 ± 4 years; 53.1% female; accuracy, >98%). Patients were stratified to pediatric (5-13 years), adolescent (14-19 years), and young adult (20-35 years) cohorts. Logistic regression was used to determine predictors of concomitant injury to the menisci, medial collateral ligament (MCL), posterolateral corner (PLC), and posterior cruciate ligament (PCL).

RESULTS

Between 2000 and 2020, 54% of pediatric, 71% of adolescent, and 70% of adult patients had ≥1 concomitant soft tissue injury. In children and adolescents, increased age was consistently predictive of sustaining a concomitant injury (P < .02). Female children had increased odds of concomitant medial meniscal injury, while female adults had decreased odds (P≤ .046). Adolescent and adult female patients had decreased odds of concomitant lateral meniscal injury (P≤ .027). Female children had increased odds of injury to the MCL (P = .015), whereas female children and adolescents had decreased odds of PCL injury (P≤ .044). Adolescents undergoing revision ACL surgery had increased odds of meniscal injury (P≤ .001) and decreased odds of concomitant MCL injury (P = .028). Increased body mass index (BMI) was associated with increased odds of concomitant medial meniscal injury in all cohorts (P≤ .041), lateral meniscal injury in adults (P = .045), and PLC injury in children (P = .016). Contact injuries were associated with increased odds of MCL injury in adolescents (P = .017) and PLC injury in adolescents and adults (P < .014).

CONCLUSION

These findings support the hypothesis, as there were multiple factors that significantly affected the risk of concomitant injuries that differed between cohorts. Increased age, BMI, and contact injury history were generally associated with increased odds of sustaining a concomitant injury, whereas female sex and revision ACL surgery had mixed effects. Further studies are essential to investigate the sex-based differences in risk for concomitant injuries and to develop tailored treatment plans that minimize the risk of secondary ACL injury.

The Prevalence and Risk Factors of Contralateral Cranial Cruciate Ligament Rupture in Medium-to-Large (≥15kg) Breed Dogs 8 Years of Age or Older

OBJECTIVE

 The aim of this study was to determine the prevalence of contralateral cranial cruciate ligament rupture (CCLR) in dogs 8 years of age or older, weighing more than or equal to 15 kg at the time of first-side CCLR and to assess associated risks.

STUDY DESIGN

 It is a cross-sectional retrospective study of 831 client-owned dogs METHODS:  Medical records of dogs weighing more than or equal to 15 kgs that were more than or equal to 8 years of age at the time of first CCLR diagnosis were reviewed. Data collected included weight, sex, pre-operative tibial plateau angle, co-morbidities, time between diagnosis of first CCLR and diagnosis of contralateral CCLR. Multivariate logistic regression analysis was used to estimate odds ratio. A median follow-up period of over 112.7 months (25th/75th quartiles 75.4/157.7 months) from first CCLR diagnosis was allotted.

RESULTS

 Eight-hundred thirty-one dogs were identified and included. About 19.1% (159/831 dogs, 95% confidence interval: 16.6-22.0%) of dogs that experience a first-side CCLR at 8 years of age or older will rupture the contralateral side, a median of 12.9 months (25th/75th quartiles 6.5/24.3 months) later. Age (p = 0.003) and breed, Golden Retrievers (p = 0.028) and Labrador Retrievers (p = 0.007), were factors significantly associated with contralateral CCLR.

CLINICAL RELEVANCE

 The prevalence of contralateral CCLR in medium-to-large breed dogs more than or equal to 8 years of age old is less than previously reported and the risk decreases as they age. This important information will help guide owners when deciding to pursue surgical stifle stabilization following CCLR in older dogs.

Incidence of and Risk Factors for Arthrogenic Muscle Inhibition in Acute Anterior Cruciate Ligament Injuries: A Cross-Sectional Study and Analysis of Associated Factors From the SANTI Study Group

BACKGROUND

Arthrogenic muscle inhibition (AMI) is a process in which neural inhibition after injury or surgery to the knee results in quadriceps activation failure and knee extension deficit.

PURPOSE

To determine the incidence and spectrum of the severity of AMI after acute anterior cruciate ligament (ACL) injury using the Sonnery-Cottet classification, to determine the interobserver reliability of the classification system, and to investigate potential important factors associated with AMI after ACL injury.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Consecutive patients who had an acute ACL injury between October 2021 and February 2022 were considered for study inclusion. Eligible patients underwent a standardized physical examination at their first outpatient appointment. This included an assessment of quadriceps inhibition, identification of any extension deficits, and grading of AMI and its reversibility according to the Sonnery-Cottet classification.

RESULTS

A total of 300 consecutive patients with acute ACL ruptures were prospectively enrolled in the study. Of them, 170 patients (56.7%) had AMI. Patients evaluated with AMI showed a significantly inferior Lysholm score, International Knee Documentation Committee score, Simple Knee Value, and Knee injury and Osteoarthritis Outcome Score than patients without AMI (P < .0001). Multivariate analysis revealed that the presence of effusion, concomitant injuries, and high pain scores were associated with a significantly greater risk of AMI. Additional associations with the presence of AMI included a short duration between injury and evaluation, the use of crutches, and using a pillow as a support at night. In contrast, a previous ACL injury was associated with significantly lower odds of developing AMI (OR, 0.025; 95% CI, 0-0.2; P = .014). Among the 170 patients with AMI, 135 patients (79%) showed a resolution of their inhibition at the end of the consultation after application of simple exercises; the remaining 35 patients required specific rehabilitation. Interobserver reliability of the classification system was almost perfect (95% CI, 0.86-0.99).

CONCLUSION

AMI occurs in over half of patients with acute ACL injuries. When it occurs, it is easily reversible in the majority of patients with simple exercises targeted at abolishing AMI. The presence of "red flags" should increase the index of suspicion for the presence of AMI, and these include the presence of an effusion, high pain scores, a short time between injury and evaluation, multiligament injuries, the use of crutches, and using a pillow as a support at night. Patients with a history of ipsilateral or contralateral ACL injury are at a significantly lower risk of AMI than those with a first-time ACL injury.

Impact of Environmental Factors on the ACL Injury Risk in Recreational Alpine Skiing

In recreational alpine skiing, an ACL injury represents the most common injury. Skiing is a complex activity where the skier interacts with the environment, such as weather, snow conditions, temperature, etc. Thus, the aim of this study was to evaluate the potential impact of environmental factors on ACL injury risk in recreational alpine skiers. Among a cohort of 392 ACL-injured skiers and 392 uninjured controls matched for sex and skiing skill, environmental factors were collected by questionnaire. Factors included weather conditions, snow conditions, perceived temperature, and slope difficulty at the time-point of the accident (ACL-injured skiers) or of questioning during the ski day (uninjured controls).Multiple logistic regression revealed that in addition to age, five environmental factors were significantly predictive of an ACL injury: fresh snow (OR 10.5), grippy snow (OR 7.8), icy slope condition (OR 12.4), very cold/cold perceived temperature (OR 1.6), and skiing on easy slopes (OR 6.9). In conclusion, besides age, environmental factors such as fresh and grippy snow, icy slope conditions, low temperatures, and flat slopes are associated with an increased ACL injury risk in recreational alpine skiing. Those factors are at least partly modifiable and should be taken into consideration for preventive strategies.

The role of relaxin in anterior cruciate ligament injuries: a systematic review

OBJECTIVE

Anterior cruciate ligament (ACL) tears are exceedingly common among the athletic population and are seen with higher incidence in females. Observational studies have noted peak ACL tear rates in the luteal phase of the menstrual cycle, a time in which the hormone relaxin peaks in serum concentration.

METHODS

A systematic review of the literature was performed. Inclusion criteria specified all prospective and retrospective studies which included the role of relaxin in the pathogenesis of ACL tears.

RESULTS

Six studies met inclusion criteria yielding 189 subjects from clinical studies and 51 in vitro samples. Included studies found that ACL samples exhibit selective relaxin binding. When pre-treated with estrogen prior to relaxin exposure, female ACL tissue samples exhibit increased expression of collagen degrading receptors.

CONCLUSION

Relaxin displays binding specificity to the female ACL and increased serum concentrations are correlated with increased ACL tear rates in female athletes. Further research is needed in this area.

LEVEL OF EVIDENCE

V.

A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Anterior Cruciate Ligament Tears and Reconstruction Failure

PURPOSE

To characterize the association between a diagnosis of hypovitaminosis D and primary anterior cruciate ligament (ACL) tear, primary anterior cruciate ligament reconstruction (ACLR), and revision ACLR in different sex and age cohorts.

METHODS

In this retrospective cohort study of the PearlDiver claims database, records were queried between January 1, 2011, and October 31, 2018 for all patients aged 10 to 59 years who received a diagnosis of hypovitaminosis D. Rates of primary ACL tears, primary reconstruction, and revision reconstruction were calculated for sex- and age-specific cohorts and compared with a control of patients without a diagnosis of hypovitaminosis D. Incidence rates for primary ACL injuries were calculated, and multivariable logistic regression was used to compare rates of ACL injury, primary reconstruction, and revision reconstruction while controlling for age, sex, Charlson Comorbidity Index, and several other comorbidities.

RESULTS

Among the 328,011 patients (mean age 41.9 ± 12.6 years, 65.8% female) included in both the hypovitaminosis D and control cohorts, the incidence of ACL tears was 115.2 per 100,000 person-years (95% confidence interval [CI] 107.2-123.7) compared with 61.0 (95% CI 55.2-67.2) in the demographic- and comorbidity-matched control cohort. The study cohort was significantly more likely to suffer an ACL tear over a 1- (aOR 1.67, 95% CI 1.41-1.99, P < .001) and 2-year (aOR 1.81, 95% CI 1.59-2.06, P < .001) period. This trend remained for both male patients at the 1- (aOR 1.66, 95% CI 1.29-2.14, P < .001) and 2-year (aOR 1.68, 95% CI 1.37-2.06, P < .001) mark and female patients at the 1- (aOR 1.69, 95% CI 1.33-2.14, P < .001) and 2-year (aOR 1.80, 95% CI 1.51-2.14, P < .001) mark. Finally, patients with vitamin D deficiency had a significantly increased likelihood of undergoing a revision ACLR within 2 years of a primary reconstruction (aOR 1.28, 95% CI 1.05-1.55, P = .012).

CONCLUSIONS

This study reports an association between patients previously diagnosed with hypovitaminosis D and significantly increased rates of both index ACL tears (81% increase within 2 years of diagnosis) and revision ACLR (28% within 2 years). These results identify a population with increased odds of injury and provide valuable knowledge as we expand our understanding of the relationship between vitamin D and musculoskeletal health.

LEVEL OF EVIDENCE

Level III, retrospective database study.

Graft failure within 2 years of isolated anterior cruciate ligament reconstruction is associated with increased risk of secondary meniscus tears

PURPOSE

A debilitating complication following anterior cruciate ligament reconstruction is a secondary meniscus tear. Currently, the literature is mixed regarding the risk factors associated with the incidence of secondary meniscus tears. The aim of this study was to investigate risk factors associated with meniscus tears following an isolated primary anterior cruciate ligament reconstruction. ACL graft failure was hypothesized to be the strongest risk factor for secondary meniscal injury occurrence.

METHODS

A retrospective cohort analysis was performed using the PearlDiver Database. Patients with a primary anterior cruciate ligament reconstruction were identified in the database. Patients with concomitant knee ligament injury or meniscus injury present at the time the index procedure were excluded. Patients were grouped to those who had a secondary meniscus tear within 2 years following anterior cruciate ligament reconstruction and those who did not. Univariate analysis and multivariable regression analysis was conducted to identify significant risk factors for a secondary meniscus tear.

RESULTS

There were 25,622 patients meeting criteria for inclusion in this study. Within 2 years from the primary anterior cruciate ligament reconstruction, there were 1,781 patients (7.0%) that experienced a meniscus tear. Graft failure had the highest odds of having a postoperative meniscus tear within 2 years (OR: 4.1; CI 3.5-4.8; p < 0.002). Additional significant risk factors included tobacco use (OR: 2.0; CI 1.0-3.1; p < 0.001), increased Charlson Comorbidity Index (OR: 1.2; CI 1.1-1.4), male gender (OR: 1.1; CI 1.1-1.2; p < 0.001), obesity (OR: 1.1; CI 1.1-1.2; p < 0.001), delayed surgery (OR:1.1; CI 1.1-1.2; p < 0.002), and patients age 30 and older (OR: 1.0; CI 1.0-1.0; p < 0.001).

CONCLUSIONS

This study found that anterior cruciate ligament graft failure is the strongest predictor of post-operative meniscus tears. Other risk factors, including tobacco use, increased CCI, male gender, obesity, delayed surgery, and age 30 and older, were established, with several being modifiable. Therefore, targeted preoperative optimization of modifiable risk factors and postoperative protocols may reduce the risk of secondary meniscus tears.

LEVEL OF EVIDENCE

Level III, prognostic trial.

Sex, military occupation and rank are associated with risk of anterior cruciate ligament injury in tactical-athletes

INTRODUCTION

Anterior cruciate ligament (ACL) injury is common within the US military and represents a significant loss to readiness. Since recent changes to operational tempo, there has not been an analysis of ACL injury risk. The aim of this retrospective cohort study was to evaluate military occupation, sex, rank and branch of service on ACL injury risk in the US military from 2006 to 2018.

METHODS

The Defense Medical Epidemiology Database was queried for the number of US tactical athletes with International Classification of Diseases diagnosis codes 717.83 (old disruption of ACL), 844.2 (sprain of knee cruciate ligament), M23.61 (other spontaneous disruption of ACL) and S83.51 (sprain of ACL of knee) on their initial encounter. Relative risk and χ2 statistics were calculated to assess sex and military occupation effects on ACL injury. A multivariable negative binomial regression model evaluated changes in ACL injury incidence with respect to sex, branch of service and rank.

RESULTS

The study period displayed a significant decrease in the ACL injury rate at 0.18 cases per 1000 person-years or relative decrease of 4.08% each year (p<0.001) after averaging over the main and interactive effects of sex, rank and branch of service. The interaction effect of time with sex indicated a steeper decline in the incidence in men as compared with women. The risk of ACL injury by sex was modified by rank. The incidence among military personnel varied by occupation.

CONCLUSION

Despite the decline among tactical athletes over time, rates of ACL injury remain much higher than the general US population. Sex, rank, branch of service and military occupation were found to be risk factors for ACL injury. It is critical for policy makers to understand the salient risk factors for ACL injury to guide proactive measures to prevent injury.

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.

Posterolateral tibial plateau bone bruises in anterior cruciate ligament (ACL) injuries and its association with lateral meniscal injuries

INTRODUCTION

This study examined the prevalence of posterolateral tibial bone bruising in isolated anterior cruciate ligament (ACL) injuries, prevalence of meniscal injuries in ACL injuries, as well as the association between posterolateral tibial bone bruising and lateral meniscal tears among those with ACL injury undergoing Primary ACL Reconstruction.

MATERIALS AND METHODS

Retrospective data on 130 patients who underwent primary ACL reconstructions was analysed. Their preoperative magnetic resonance images (MRI) were reviewed for the presence of posterolateral tibial bone bruise. The presence of meniscal injuries was recorded based on the arthroscopic findings from the operative records.

RESULTS

95 patients were recruited into the study. The prevalence of posterolateral bone bruise in this study was 41%. There was a statistically significant difference when comparing the prevalence of bone bruising to the time of injury to MRI (p<0.001). The prevalence of an injury to at least one meniscus at the time of ACLR surgery was 83.2%. The prevalence of lateral meniscus injuries in patients with bone bruise was found to be 53.9%. The crude odds ratio of a patient having a lateral meniscal tear in the presence of bone bruising was 1.56 (0.68, 3.54). This figure was even higher when it was adjusted for time to MRI and was 2.06 (0.77, 5.46).

CONCLUSION

Prevalence of posterolateral tibial bone bruising in our study was 41%, and the prevalence of meniscal injury to either meniscus at the point of surgery was 83.2%, out of which the lateral meniscus tears were identified during ACLR surgery in 47.3% of the patients. We found there was no association between posterolateral tibial bone bruising to sex, age and mode of injury, but was sensitive to the interval between time of injury and MRI. The overall prevalence of lateral meniscal tears was higher in patients with posterolateral bone bruising but was not statistically significant with a P value of 0.31; however, the Crude odd ratio was 1.56 (0.68, 3.54) and was higher when adjusted to time of injury to MRI 2.06 (0.77, 5.46). We suggest for MRI to be done as soon as possible after injury in regard to bone bruising identification. We should be vigilant to look for lateral meniscal tears and anticipate for its repair in ACL injuries, especially so when we identify posterolateral tibial bruising on the preoperative MRI.

ACL Injuries in Soccer Players: Prevention and Return to Play Considerations

Soccer is the most popular sport in the world, with an estimated 270 million people, or 4% of the world's population, currently playing.1 Soccer has recently enjoyed an elevated profile with the US women's national team competing in the 2023 World Cup. Meanwhile, there is regional excitement with Kansas City selected as a host city of the upcoming 2026 men's World Cup (logo left). Knee injuries, particularly ACL tears, are common in soccer and can lead to extensive time away from sport. Increasing emphasis is being placed on reducing soccer related injuries as well as improving outcomes when returning players back to competitive play.

Prevalence of post-traumatic osteoarthritis after anterior cruciate ligament injury remains high despite advances in surgical techniques

Aims

The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades.

Methods

The PubMed and Web of Science databases were searched from 1 January 1980 to 11 May 2022. Patient series, observational studies, and clinical trials having reported the prevalence of radiologically confirmed PTOA after ACL injury, with at least a ten-year follow-up, were included. All studies were analyzed simultaneously, and separate analyses of the operative and nonoperative knees were performed. The prevalence of PTOA was calculated separately for each study, and pooled prevalence was reported with 95% confidence intervals (CIs) using either a fixed or random effects model. To examine the effect of the year of injury on the prevalence, a logit transformed meta-regression analysis was used with a maximum-likelihood estimator. Results from meta-regression analyses were reported with the unstandardized coefficient (β).

Results

The pooled prevalence of PTOA was 37.9% (95% CI 32.1 to 44) for operatively treated ACL injuries with a median follow-up of 14.6 years (interquartile range (IQR) 10.6 to 16.7). For nonoperatively treated ACL injuries, the prevalence was 40.5% (95% CI 28.9 to 53.3), with a median of follow-up of 15 years (IQR 11.7 to 20.0). The association between the year of operation and the prevalence of PTOA was weak and imprecise and not related to the choice of treatment (operative β -0.038 (95% CI -0.076 to 0.000) and nonoperative β -0.011 (95% CI -0.101 to 0.079)).

Conclusion

The initial injury, irrespective of management, has, by the balance of probability, resulted in PTOA within 20 years. In addition, the prevalence of PTOA has only slightly decreased during past decades. Therefore, further research is warranted to develop strategies to prevent the development of PTOA after ACL injuries.

High prevalence of associated intra-articular injuries with increasing time period from anterior cruciate ligament injury to reconstruction, even in apparent copers

BACKGROUND

It still unclear whether copers may bear the same time-sensitive risk of intra-articular injury as non-copers. The objectives were to investigate the clinical characteristics of copers and non-copers that have sustained an anterior cruciate ligament (ACL) injury, and to examine and compare the intra-articular pathologies in delayed ACL reconstruction (ACLR) in copers and noncopers.

METHODS

Patients who sustained ACL injury while participating in high-performance sports and opted for non-operative treatment were enrolled in this study. Depending on the occurrence of the knee giving way, patients were classified into copers and noncopers. Clinical characteristics were compared between the two groups. Additionally, intra-articular injuries were evaluated for those who eventually underwent delayed ACLR.

RESULTS

11 of the 75 patients (14.7%) were classified as copers. No major differences were found in the clinical characteristics between groups. Following the initial non-operative treatment, 67 patients underwent delayed ACLR. When examining intra-articular abrasions at the time of surgery, non-copers who continued sports activities for 3 to 12 months exhibited a significantly higher rate of injury as opposed to their coper counterparts. However, the difference in the prevalence of intra-articular lesions between the two groups in patients who continued to play sports for at least 12 months before surgery was nominal.

CONCLUSION

The rate of copers was relatively low in patients who resumed playing high-level sports after ACL injury. Additionally, even in copers, those who continued sports activities for more than 12 months had comparably high prevalence of intra-articular injuries with noncopers.

STUDY DESIGN

Retrospective case-control study; Level of evidence, 3.

Meniscal injuries in skeletally immature children with tibial eminence fractures. Systematic review of literature

PURPOSE

Although the mechanisms of injury are similar to ACL rupture in adults, publications dealing with meniscal lesions resulting from fractures of the intercondylar eminence in children are much rarer. The main objective was to measure the frequency of meniscal lesions associated with tibial eminence fractures in children. The second question was to determine whether there is any available evidence on association between meniscal tears diagnostic method, and frequencies of total lesions, total meniscal lesions, and total entrapments.

METHODS

A comprehensive literature search was performed using PubMed and Scopus. Articles were eligible for inclusion if they reported data on intercondylar tibial fracture, or tibial spine fracture, or tibial eminence fracture, or intercondylar eminence fracture. Article selection was performed in accordance with the PRISMA guidelines.

RESULTS

In total, 789 studies were identified by the literature search. At the end of the process, 26 studies were included in the final review. This systematic review identified 18.1% rate of meniscal tears and 20.1% rate of meniscal or IML entrapments during intercondylar eminence fractures. Proportion of total entrapments was significantly different between groups (17.8% in the arthroscopy group vs. 6.2% in the MRI group; p < .0001). Also, we found 20.9% of total associated lesions in the arthroscopy group vs. 26.1% in the MRI group (p = .06).

CONCLUSION

Although incidence of meniscal injuries in children tibial eminence fractures is lower than that in adults ACL rupture, pediatric meniscal tears and entrapments need to be systematically searched. MRI does not appear to provide additional information about the entrapment risk if arthroscopy treatment is performed. However, pretreatment MRI provides important informations about concomitant injuries, such as meniscal tears, and should be mandatory if orthopaedic treatment is retained. MRI modalities have yet to be specified to improve the diagnosis of soft tissues entrapments.

STUDY DESIGN

Systematic review of the literature REGISTRATION: PROSPERO N° CRD42021258384.

Delaying ACL reconstruction is associated with increased rates of medial meniscal tear

PURPOSE

The aim of this study was to evaluate the relationship between the time from injury to ACL reconstruction (ACLR) and the rate as well as repairability of meniscal tears. Secondary aims were to evaluate the relationship between meniscal injury and Tegner Activity Scale, age, BMI, and gender.

METHODS

Between 2012 and 2022, 1,840 consecutive ACLRs were performed. A total of 1,317 ACLRs were included with a mean patient age of 31.2 years ± 10.5 [16-60]. Meniscal tear was assessed during arthroscopy using the ISAKOS classification. Time from injury to ACLR, Tegner Activity Scale, age, BMI and gender were analysed in uni- and then in multivariate analyses. Patients were divided into four groups according to the time from injury to surgery: < 3 months (427; 32%), 3-6 months (388; 29%), 6-12 months (248; 19%) and > 12 months (254; 19%).

RESULTS

Delaying ACLR > 12 months significantly increased the rate of medial meniscal (MM) injury (OR 1.14; p < 0.001). No correlation was found between a 3- or 6-month time from injury to surgery and MM tear. Performing ACLR > 3, 6, or 12 months after injury did not significantly increase the rate of lateral meniscal (LM) injury. Increasing Tegner activity scale was significantly associated with a lower rate of MM injury (OR 0.90; p = 0.020). An age > 30 years (OR 1.07; p = 0.025) and male gender (OR 1.13; p < 0.0001) was also associated with an increased rate of MM injury. Age > 30 years decreased the rate of MM repair (OR 0.85; p < 0.001). Male gender increased the rate of LM tear (OR 1.10; p = 0.001).

CONCLUSION

Performing ACLR more than 12 months after injury was associated with increased rates of MM injury but not with lower rates of repairable lesions. An increased pre-injury Tegner activity score was associated with a decreased rate of MM tear. Age > 30 years was associated with an increased rate of MM tear with concomitant ACL injury and a decreased rate of repairability of MM tear. ACLR should be performed within 12 months from injury to prevent from the risk of MM injury.

LEVEL OF EVIDENCE

Level III.

Major Increase in Incidence of Pediatric ACL Reconstructions From 2005 to 2021: A Study From the Norwegian Knee Ligament Register

BACKGROUND

The incidence of pediatric and adolescent anterior cruciate ligament reconstruction (ACLR) is increasing in several countries. It is uncertain whether this trend applies to countries that traditionally prefer an initial nonoperative treatment approach whenever possible, like Norway. Nationwide, long-term patient-reported outcomes and revision rates after ACLR in the pediatric population are also lacking.

PURPOSE

To determine the incidence of pediatric ACLR in Norway since 2005, as well as to detect trends in surgical details and describe patient-reported outcomes up to 10 years after ACLR.

STUDY DESIGN

Descriptive cohort study.

METHODS

This study is based on prospectively collected data on girls ≤14 years and boys ≤16 years, registered in the Norwegian Knee Ligament Register at the time of their primary ACLR, between 2005 and 2021. The main outcome was the incidence of ACLR, adjusted to the corresponding population numbers for each year. The time trend was analyzed by comparing the mean of the first and last 3-year period (2005-2007 and 2019-2021). Patient-reported outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score preoperatively and at 2, 5, and 10 years postoperatively.

RESULTS

A total of 1476 patients (1484 cases) were included, with a mean follow-up of 8.1 years (range, 1-17). The incidence of pediatric ACLRs per 100,000 population increased from 18 to 26, which corresponds to an increase of 40% for boys and 55% for girls. Concurrent meniscal procedures increased significantly from 45% to 62%, and the proportion of meniscal repairs increased from 19% to 43% when comparing the first and last time period. The mean Knee injury and Osteoarthritis Outcome Score values for the Sport and Recreation and Quality of Life subscales were between 72 and 75 at the 2-, 5- and 10-year follow-up. The 5-year revision rate was 9.9%.

CONCLUSION

There was a major increase in incidence of pediatric ACLR in Norway during the study period. There was a shift in the approach to concomitant meniscal procedures from resection to repair, with more than a doubling of the proportion of meniscal repairs. Patient-reported outcomes revealed long-lasting reduced knee function.

Identifying modifiable risk factors and screening strategies associated with anterior cruciate ligament injury risk in children aged 6 to 13 years: A systematic review

Growing anterior cruciate ligament (ACL) injury incidence is reported in countries across Europe, North America and in Australia for 5-14-year-olds, yet research on injury risk reduction predominantly focuses on populations aged > 13 years. For injury risk reduction, it is crucial to understand (i) which modifiable risk factors are associated with ACL injury in children (6-13 years) and (ii) how these risk factors are assessed. Articles were grouped according to sex/gender and/or maturational/age differences and examined modifiable risk factors during different physical screening tasks. The included articles (n = 40) predominantly examined intrinsic risk factors in girls aged 10-13 years. Factors mechanically linked to increased ACL loading at this age included increased peak knee adductor moments, knee valgus angles, hip and knee extension, and ground reaction forces. Assessment focused on laboratory-based assessments (e.g., motion capture, force plates). This review concluded that modifiable risk factors are present in children aged 6-13 years and that injury risk reduction strategies should be implemented as early as possible regardless of sex/gender. Further, screening strategies need updating to be childhood specific and feasible for the wide community. Additional research on extrinsic risk factors, norm values and children aged 6-9 years could allow for more targeted risk reduction strategies.

Healthcare Disparities in Orthopaedic Surgery: A Comparison of Anterior Cruciate Ligament Reconstruction Incidence Proportions With US Census-Derived Demographics

INTRODUCTION

Disparities exist and affect outcomes after anterior cruciate ligament (ACL) injury. The purpose of this study was to investigate the association between race, ethnicity, and insurance type on the incidence of ACL reconstruction in the United States.

METHODS

The Healthcare Cost and Utilization Project database was used to determine demographics and insurance types for those undergoing elective ACL reconstruction from 2016 to 2017. The US Census Bureau was used to obtain demographic and insurance data for the general population.

RESULTS

Non-White patients undergoing ACL reconstruction with commercial insurance were more likely to be younger, male, less burdened with comorbidities including diabetes, and less likely to smoke. When we compared Medicaid patients who had undergone ACL reconstruction with all Medicaid recipients, there was an under-representation of Black patients and a similar percentage of White patients undergoing ACL reconstruction (P < 0.001).

DISCUSSION

This study suggests ongoing healthcare disparities with lower rates of ACL reconstruction for non-White patients and those with public insurance. Equal proportions of patients identifying as Black undergoing ACL reconstruction as compared with the underlying general population suggests a possible narrowing in disparities. More data are needed at numerous points of care between injury, surgery, and recovery to identify and address disparities.

Anterior Cruciate Ligament Tear Using Magnetic Resonance Imaging among Patients Undergoing Arthroscopy in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Magnetic Resonance Imaging is the preferred imaging modality in patients having anterior cruciate ligament tears. The aim of this study was to find out the prevalence of anterior cruciate ligament tears using magnetic resonance imaging among patients undergoing arthroscopy in a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted in the Department of Orthopaedics and Traumatology of a tertiary care centre. Data from 17 November 2017 to 17 October 2022 were collected between 26 December 2022 and 30 December 2022 from the hospital records. Ethical approval was obtained from Institutinal Review Committee of the same institute (Reference number: 233/22). All patients with a knee injury who received arthroscopy were included in the study. Magnetic resonance imaging reports, arthroscopic findings and relevant data of each case were retrieved from the medical case records of patients. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.

Results

Among patients with arthroscopy confirmed anterior cruciate ligament tear, 138 (91.39%) (86.92 to 95.86, 95% Confidence Interval) had anterior cruciate ligament tear diagnosed with magnetic resonance imaging. The mean age of the patients who had anterior cruciate ligament tear in the magnetic resonance imaging was 32.35±11.31 years. Out of them, 87 (63%) were males and 51 (37%) were females. The mean duration of the injury was 11.60±18.47 months.

Conclusions

The prevalence of anterior cruciate ligament tear using magnetic resonance imaging among patients undergoing arthroscopy in tertiary care centres was similar when compared to other similar studies when conducted in similar settings.

Keywords

anterior cruciate ligament tears; arthroscopy; cross-sectional studies; MRI.

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects.

RESULTS

A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

Incidence of acute injuries in Swedish gymnastics with a special focus on cruciate ligament injuries

BACKGROUND

Gymnastics is a sport with unique technical and physical demands. Elements of high rotational landing impacts may lead to severe injuries. In order to understand the risks of the sport and design injury prevention programs the magnitude of acute injuries must be understood. The aim was to investigate acute injuries, medical invalidity and injury costs in gymnastics using national insurance data.

METHODS

Insurance data covering acute injuries in Swedish gymnastics from October 2015 to October 2020 were analyzed. All Swedish gymnasts with either a training or competition license were included (N.=333,932 licenses, 249,823 females; 84,109 males).

RESULTS

A total of 1733 acute injuries were reported, and the injury incidence was 5.2 per 1000 gymnast years, with no differences between upper and lower body. The arm followed by the foot and the knee were body locations with highest injury incidence. Skeletal injuries were most common in the arm and foot, and ligament injuries in the foot and knee. The proportion of cruciate ligament injuries was 37% of all knee injuries and 5% of all acute injuries. No significant difference between male and female gymnasts was observed. The highest proportion of medical invalidity was found in the knee (33%), the foot (22%), and the arm (20%). Sixteen percent of all cruciate ligament injuries led to medical invalidity and was the injury causing highest costs to the insurance company.

CONCLUSIONS

The knee was the third most common injury location and the injury causing the highest medical invalidity.

A Comparison of ACL Injury Risk, Ski Geometry and Standing Height Parameters between Skiers with Rented and with Owned Skis

to evaluate if ACL injuries are associated with recreational skiers using rented skis and whether individual factors, ski geometry parameters and standing heights differ between skiers who rented or owned skis. A retrospective questionnaire-based, case-control study of ACL-injured and uninjured recreational skiers was conducted during six winter seasons. Age, sex, body height, body weight, nationality, ownership of skis, skill level, risk-taking behavior, ski length, side-cut radius, widths of the tip, waist, and tail, and the standing heights at the front and rear components of the ski binding were assessed. Additionally, ratios between ski widths and a standing height ratio were calculated. Altogether, 1780 skiers (48.9% females) with a mean age of 39.2 ± 13.0 years participated, of whom 22.0% sustained an ACL injury and 32.3% rented skis. ACL injury risk was significantly associated with rented skis (OR 3.2, 95% CI 2.5-4.0). Compared to skiers using own skis, participants who rented skis were more likely female, smaller and lighter, tourists, less skilled and more cautious. In comparison to owned skis, rented skis showed significantly lower mean values in ski length, side-cut radius, ski widths, and for the three ski widths ratios. Additionally, standing heights were significantly lower while standing height ratio was higher for rented skis. Beside individual factors, equipment-related factors should be considered when renting skis in order to reduce ACL injury risk.

Trends in Pediatric Anterior Cruciate Ligament Reconstruction: The Effect of COVID-19

CONTEXT

The number of pediatric anterior cruciate ligament reconstructions (ACLRs) occurring yearly increased almost 6-fold from 2004-2014. We find it interesting that limited recent data exist on rates of ACL injury and reconstruction in children and adolescents, especially in the context of COVID-19.

OBJECTIVE

Given the effect of the COVID-19 pandemic on youth sports seasons and the postponement of many elective surgeries, we sought to examine the changes in rates of ACLR during this period.

DESIGN

Retrospective cohort study.

SETTING

This study used the Pediatric Health Information System (PHIS) database to identify eligible patients at PHIS-participating hospitals nationwide from January 2016-June 2021, with March 1, 2020, considered the start of the COVID-19 pandemic.

PATIENTS OR OTHER PARTICIPANTS

Using Current Procedural Terminology codes, patients 18 years old and younger who underwent ACLR surgery were identified.

MAIN OUTCOME MEASURE(S)

Patient demographics and overall rates of surgery prepandemic and intrapandemic were compared. Data were analyzed using bivariate, mixed-model, and time series analyses.

RESULTS

A total of 24 843 ACLRs were identified during this time period. In total, 1853 fewer surgeries than expected were performed after March 2020 given prepandemic trends. Intrapandemic demographics revealed an increase in the proportion of patients who identified as White and with private insurance and a decrease in the proportion who identified as Black and with public insurance. Also, the proportion of ACLRs by region shifted, with more surgeries performed in the Midwest and fewer in the Northeast. In the model adjusted for hospital-level variability, only race and insurance status remained significant.

CONCLUSIONS

Based on prepandemic trends, fewer patients than projected underwent ACLR once the pandemic began, likely due to a combination of decreased rates of injury and delayed surgery.

Perceived Kinesiophobia and Its Association with Return to Sports Activity Following Anterior Cruciate Ligament Reconstruction Surgery: A Cross-Sectional Study

Background: The knee joint is one of the most important joints in terms of its functions of providing great stability, movement and weight bearing. Among the contributors to knee joint stability, there is the anterior cruciate ligament (ACL). Kinesiophobia is said to be the fear of movement or the fear of re-injury. Kinesiophobia is the most extreme form of fear of movement, and it is defined as an excessive, irrational, and debilitating fear of physical movement and activity resulting from a feeling of vulnerability to painful injury or re-injury. Aim: To estimate the prevalence and effect of kinesiophobia among patients with ACL reconstruction in the Aseer region, in southern Saudi Arabia. Methodology: A descriptive cross-sectional approach was used involving those patients who underwent ACL reconstruction surgery in Aseer Central Hospital during the period of October 2017 to October 2019. The Tampa Scale for Kinesiophobia (TSK) and ACL-Return to Sport after Injury (ACL-RSI) scale were used to determine kinesiophobia and the readiness to return to sport after ACL injury or reconstructive surgery. Result: The research included 130 ACL reconstruction patients with ages ranging from 18 to 45 years with a mean age of 27.2 + 7.5 years. More than 97% of the participants were males. In 67.7% of the cases, the right leg was affected. A total of 10.8% of the patients recorded a low level of kinesiophobia, while only 6.9% recorded a high level. Conclusions: In conclusion, the study revealed that among patients who underwent ACL reconstruction, kinesiophobia was at a moderate level. Kinesiophobia was recorded more among middle-aged patients who waited a long time from the onset of injury until the ACL reconstruction surgery time.

[Rupture of the anterior cruciate ligament in women]

Rupture of the anterior cruciate ligament (ACL) is a frequent injury, and it affects women more often than men. The increased incidence in females was attributed to biological, anatomical, and mechanical differences when compared to males' counterparts. Hormones, menstrual cycle, and genetic factors are also implicated. Dynamic factor such as hip, knee and ankle biomechanics while jumping, landing, and cutting activities are established contributors to ACL rupture in females. Social and economic aspects both is sports and daily life are currently implicated in increased risk of injury and delayed return to sport. Therefore, they should be taken into consideration when studying ACL injury risk factors and when developing rehabilitation and prevention programs.

Prevention of Non-Contact Anterior Cruciate Ligament Injuries among Youth Female Athletes: An Umbrella Review

Anterior cruciate ligament (ACL) injuries account for a large percentage of knee injuries, disproportionately affecting female athletes. To help health professionals stay current, we performed an umbrella review to evaluate the effectiveness of ACL injury prevention programs in reducing non-contact ACL injury rates, determine the effective components within interventions, and provide clinical recommendations. Twelve databases (Medline, Embase, Cochrane Database of Systematic Reviews, SPORTDiscus, Cumulative Index to Nursing and Allied Health Literature, PEDro, Web of Science Core Collection, Epistemonikos, TRIP, BC Guidelines and Protocols, CPG Infobase, ProQuest Dissertations and Theses Global) were searched in May 2021 to identify relevant systematic reviews and meta-analyses. Four databases were searched again in September 2021 to identify recent primary literature. Non-contact ACL injury data were extracted to calculate incidence rate ratios (IRRs) and these were combined using an inverse variance random-effects model. A qualitative assessment of included reviews was performed. The methodological quality of the studies was assessed using a Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) or Cochrane Risk-of-Bias Tool for Randomized Trials (RoB 2). Sixteen reviews and two primary studies met the inclusion criteria. Across 11 primary studies, prevention programs were effective in reducing non-contact ACL injuries by 64% (IRR = 0.36 (95% CI: 0.18–0.70)). A multi-faceted exercise program, beginning in the pre-season and containing at least three exercise types, may be beneficial in reducing ACL injury risk.

Rates of Infection After ACL Reconstruction in Pediatric and Adolescent Patients: A MarketScan Database Study of 44,501 Patients

BACKGROUND

Numerous studies have demonstrated an increase in the number of anterior cruciate ligament (ACL) reconstruction procedures performed in pediatric patients. Despite this, most knowledge of surgical site infection rates after these procedures are based on adult studies and data is currently limited in pediatric patients. The purpose of this study was to describe and analyze the rates of infection after ACL reconstruction among pediatric patients and adolescent patients (compared with young adult patients) utilizing the MarketScan Commercial Claims and Encounters Database.

METHODS

The Truven Health Analytics MarketScan Commercial Claims and Encounters database was assessed to access health care utilization data for privately insured individuals aged 5 to 30 years old. ACL reconstruction records performed between 2006 and 2018 were identified using Current Procedures Terminology (CPT) codes. International Classification of Diseases Ninth Revision (ICD-9), Tenth (ICD-10) codes and CPT codes were used to identify patients requiring treatment for infection. All patients had at least 180 days of insurance coverage after intervention.

RESULTS

A total of 44,501 individuals aged below 18 years old and 63,495 individuals aged 18 to 30 years old that underwent arthroscopic ACL reconstruction were identified. There were no differences in infection rates between those below 18 years old (0.52%) and those above 18 years old (0.46%, P=0.227). However, among patients below 18 years old, patients below 15 years old had a significantly lower rate of infection at 0.37% compared with adolescents (15 to 17 y old) at 0.55% (P=0.039). Among young adults, males had higher rates of infection than females (0.52% vs. 0.37%), while no difference was observed in the pediatric and adolescent population (0.58% vs. 0.47%, P=0.109).

CONCLUSION

Utilizing an insurance database, this study demonstrated that rates of infection after ACL Reconstruction in a pediatric/adolescent population are low (0.52%) and similar to rates in young adults. Infection rates after ACLR reconstruction appear to be slightly lower in patients under 15 years of age (0.37%).

LEVEL OF EVIDENCE

Level III-Retrospective comparative study.

Anterior Cruciate Ligament Injury and Knee Osteoarthritis: An Umbrella Systematic Review and Meta-analysis

OBJECTIVE

To conduct a systematic review of reviews to summarize the (1) risk for development and (2) prevalence of knee osteoarthritis (OA) after anterior cruciate ligament (ACL) injury and surgical treatment and (3) compare prevalence rates between surgical and nonsurgical treatment of ACL injury.

DATE SOURCES

Five electronic databases were searched using medical subject heading and text words up to February 2020 to identify English language reviews.

STUDY SELECTION

Studies were included if they were a systematic review or meta-analysis.

DATA EXTRACTION

Thirteen eligible reviews were included, and the main outcome extracted was knee OA prevalence or risk data and any meta-analysis results.

DATA SYNTHESIS

Results from reviews were combined with a summary meta-analysis based on odds ratios (ORs) or proportions. There was a near 7-fold and 8-fold increase in the odds for the development of knee OA post ACL injury [OR = 6.81 (5.70-8.13)] and ACL reconstruction [OR = 7.7, (6.05-9.79)]. Data were too heterogenous to specify a point estimate prevalence for OA after ACL injury, but OA prevalence was estimated at 36% (19.70-53.01) at near 10 years after reconstruction surgery. A significantly higher prevalence of OA was found for those who received surgical treatment at a minimum 10-year follow-up [OR = 1.40 (1.17-1.68)].

CONCLUSIONS

This study combines all data from previous systematic reviews into a single source to show that ACL injury markedly increases the risk for development of knee OA, which is likely to be present in the long term in approximately a third of patients who have reconstruction surgery. Surgical treatment does not reduce OA prevalence in the longer term compared with nonsurgical treatment.

Different injury patterns exist among patients undergoing operative treatment of isolated PCL, combined PCL/ACL, and isolated ACL injuries: a study from the Swedish National Knee Ligament Registry

PURPOSE

To compare demographic characteristics and concomitant injury patterns in patients undergoing primary isolated posterior cruciate ligament reconstruction (PCL-R) and combined posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL) reconstruction (PCL-R/ACL-R) with isolated ACL reconstruction (ACL-R) as a reference using data from the Swedish National Knee Ligament Registry (SNKLR).

METHODS

This cohort study based on the SNKLR comprised patients undergoing either PCL-R, ACL-R, or combined PCL-R/ACL-R between January 1, 2005 and December 31, 2019 in Sweden. Demographic and surgery-related data with regards to injury mechanism, concomitant intraarticular lesions and their treatment, neurovascular damage, and concomitant ligamentous injuries were extracted. Exclusion criteria included concomitant fractures of the femur, fibula, patella or tibia, and quadriceps or patellar tendon injury.

RESULTS

A total of 45,564 patients were included in this study. Isolated PCL-R, combined PCL-R/ACL-R, and isolated ACL-R were performed in 192 (0.4%), 203 (0.5%) and 45,169 (99.1%) patients, respectively. Sports were identified as the cause of 64% of PCL-Rs, 54% of PCL-R/ACL-Rs, and 89% of ACL-Rs, while a traffic-related mechanism was identified in 20% of PCL-Rs, 27% of PCL-R/ACL-Rs and 2% of ACL-Rs. Meniscus injury prevalence was 45% in ACL-Rs, 31% in PCL-R/ACL-Rs and 16% in isolated PCL-Rs (p < 0.001). Cartilage injuries were more common in PCL-R (37%) and PCL-R/ACL-R patients (40%) compared to ACL-R patients (26%, p < 0.001). Concomitant knee ligament injury was identified in 28-44% of PCL-R/ACL-R patients. Neurovascular injuries were present in 9% of PCL-R/ACL-Rs, 1% of PCL-Rs, and 0.3% of ACL-Rs (p < 0.001).

CONCLUSION

Differences in injury mechanisms among patient groups confirm that operatively treated PCL tears are frequently caused by both traffic and sports. Cartilage and ligament injuries were more frequent in patients with PCL-R compared to ACL-R. Consequently, combined PCL and ACL tears should raise suspicion for concomitant knee lesions with clinical relevance during the operative treatment of these complex injuries.

LEVEL OF EVIDENCE

III.

Patterns of presentation and early treatment outcomes of anterior cruciate ligament injury at the National Orthopaedic Hospital, Lagos, Nigeria: a retrospective cross-sectional study

The purpose of this study was to determine the patterns of presentation and early treatment outcomes of anterior cruciate ligament tears at the National Orthopaedic Hospital, Lagos, Nigeria. This was a retrospective cross-sectional study in which the details of all anterior cruciate ligament injuries seen from January 2014 to December 2018 in our facility were noted. The bio-demographic details of the patients were noted as well as the side of the injury, mechanism of injury, type of sporting activity patient was engaged in at the time of injury and the early outcome of treatment of the patients were noted. A total of 19,707 new orthopaedic and musculoskeletal trauma cases were seen in the period. The overall hospital period prevalence rate of anterior cruciate ligament injury in the period was 3.6 per 1000 patients with a gender-specific prevalence rates of 5.7 per 1000 and 1.6 per 1000 for male and female patients respectively. The mean time between injury and presentation was 16 (±21) months with a range of 1-120 months. The commonest aetiology of anterior cruciate ligament injury was non-contact injury during sporting activities. There was a greater involvement of the young and active population in this injury. Sports and road traffic crash related injuries were the commonest injury aetiology in our environment. The early treatment outcomes revealed a significant improvement of the post-operative functional knee scores over the pre-operative functional knee scores.

Steep posterior lateral tibial slope, bone contusion on lateral compartments and combined medial collateral ligament injury are associated with the increased risk of lateral meniscal tear

PURPOSE

To determine the risk factors for lateral meniscus and root tears in patients with acute anterior cruciate ligament (ACL) injuries.

METHODS

A total of 226 patients undergoing acute ACL reconstruction were included in the study sample. Exclusion criteria were revisions, fractures, chronic cases, and multiple ligament injuries, with the exception of medial collateral ligament (MCL) injuries. The patients were divided into groups based on the presence of lateral meniscus and root tears by arthroscopy. Binary logistic regression was used to analyze risk factors including age, sex, body mass index (BMI), injury mechanism (contact/non-contact), Segond fracture, side-to-side laxity, location of bone contusion, medial and lateral tibial and meniscal slope, mechanical axis angle, and grade of pivot shift.

RESULTS

Overall lateral meniscus (LM) tears were identified in 97 patients (42.9%), and LM root tears were found in 22 patients (9.7%). The risk of an LM tear in ACL-injured knees increased with bone contusion on LTP (odds ratio [OR], 3.5; 95% confidence interval [CI] 1.419-8.634; P = 0.007), steeper lateral tibial slope (OR, 1.133; 95% CI 1.003-1.28; P = 0.045), MCL injury (OR, 2.618; 95% CI 1.444-4.746; P = 0.002), and non-contact injury mechanism (OR, 3.132; 95% CI 1.446-6.785; P = 0.004) in logistic regression analysis. The risk of LM root tear in ACL-injured knees increased with high-grade pivot shift (OR, 9.127; 95% CI 2.821-29.525; P = 0.000) and steeper lateral tibial slope (OR, 1.293; 95% CI 1.061-1.576; P = 0.011).

CONCLUSION

The increased risk of LM lesions in acute ACL-injured knees should be considered if significant risk factors including bone contusion on lateral compartments, MCL injury, and a steeper lateral tibial slope are present. Moreover, high-grade rotational injury with steeper lateral tibial slope are also significant risk factors for LM root tears, and therefore care should be taken by clinicians not to miss such lesions.

LEVEL OF EVIDENCE

III.

Exercise-Based Training Strategies to Reduce the Incidence or Mitigate the Risk Factors of Anterior Cruciate Ligament Injury in Adult Football (Soccer) Players: A Systematic Review

Anterior cruciate ligament (ACL) is one of the most concerning injuries for football players. The aim of this review is to investigate the effects of exercise-based interventions targeting at reducing ACL injury rate or mitigating risk factors of ACL injury in adult football players. Following PRISMA guidelines, a systematic search was conducted in CINAHL, Cochrane Library, PubMed, Scopus, SPORTDiscus and Web of Science. Studies assessing the effect of exercise-based interventions in ACL injury incidence or modifiable risk factors in adult football players were included. 29 studies evaluating 4502 male and 1589 female players were included (15 RCT, 8 NRCT, 6 single-arm): 14 included warm-up, 7 resistance training, 4 mixed training, 3 balance, 1 core stability and 1 technique modification interventions. 6 out of 29 studies investigated the effect of interventions on ACL injury incidence, while the remaining 23 investigated their effect on risk factors. Only 21% and 13% studies evaluating risk of injury variables reported reliability measures and/or smallest worthwhile change data. Warm-up, core stability, balance and technique modification appear effective and feasible interventions to be included in football teams. However, the use of more ecologically valid tests and individually tailored interventions targeting specific ACL injury mechanisms are required.

Identifying Clinical and MRI Characteristics Associated with Quality of Life in Patients with Anterior Cruciate Ligament Injury: Prognostic Factors for Long-Term

BACKGROUND

Associated lesions in the diagnostic MRI may be related to worse long-term subjective outcomes. There is a lack of conclusive information about the long-term outcomes of associated injuries in anterior cruciate ligament (ACL) tears. The purpose of this study is to assess the long-term effects of associated injuries in ACL tears measured by means of a quality of life (QOL) assessment.

METHODS

A retrospective cohort study of 225 consecutive patients admitted for physical therapy with ACL injury (42 ± 12 years, 28.2% female) were conducted. All demographic and clinical variables were used to measure a QOL. Univariate and multivariable analyses were completed.

RESULTS

The mean follow-up period was 8.4 ± 2.6 years. In univariate analysis, male gender, and sports as the cause of the ACL lesion were factors significantly associated with improved International Knee Documentation Committee (IKDC) scores at the end of follow-up (all p < 0.002). In multivariable analysis, the occurrence of bone contusion was positively associated with injury (OR = 2.12) and negatively associated with sports injury (OR = 0.44) and medial collateral ligament (MCL) injury (OR = 0.48).

CONCLUSIONS

After ACL injury, male gender and sports injury were associated with better clinical outcomes.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients

PURPOSE

While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear.

METHODS

Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified. These patients were matched by age and sex to patients undergoing primary ACL reconstruction who were not found to have lateral meniscus root tears (control group) in a 1:1 ratio. Lateral posterior tibial slope (PTS), medial PTS, lateral femoral condyle height and depth, lateral tibial plateau depth, and lateral tibial plateau subluxation were measured on MRI. Anteroposterior full-limb alignment radiographs were used to measure the medial proximal tibia angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), and the mechanical weightbearing axis for the injured extremity.

RESULTS

One-hundred three patients were included in both the LMPRT group and the matched control group. Patients with a LMPRT had a significantly steeper lateral PTS (9.1° vs. 7.0°, p = 0.001), a steeper medial PTS (7.0° vs. 6.0°, p = 0.03), and a greater lateral-to-medial slope asymmetry (2.0° vs. 1.0°, p = 0.001). There were no differences in lateral femoral condyle depth or height, lateral tibial plateau depth, lateral tibial plateau subluxation, MPTA, mLDFA, or mechanical weightbearing axis between groups. There was a significantly increased incidence of medial meniscus ramp lesions in patients with lateral meniscus posterior root tears compared with controls (34.0% vs. 15.5%, odds ratio: 2.8, p = 0.002). There were no associations with concomitant ligament injuries, medial meniscus root tears, or non-ramp tears based on case/control grouping.

CONCLUSION

In conclusion, LMPRTs in the setting of primary ACL injuries were associated with significantly increased lateral and medial PTSs, and increased asymmetry between lateral and medial PTSs. In addition, clinicians should be aware of the increased incidence of concurrent medial meniscal ramp lesions in patients with LMPRTs. Knowledge of these associations helps guide clinical decision-making and counselling of patients in the setting of ACL tears with concomitant LMPRTs.

LEVEL OF EVIDENCE

IV.

Anatomic characteristics of the knee influence the risk of suffering an isolated meniscal injury and the risk factors differ between women and men

PURPOSE

To analyse the relationship between multiple anatomic characteristics of the knee (tibia and femur) and isolated meniscal injury in women and men.

METHODS

Forty-seven patients with isolated medial meniscal injuries, 62 patients with isolated lateral meniscal injuries, and 70 control subjects were included. Medial posterior tibial slope (MTS), lateral posterior tibial slope (LTS), medial tibial plateau depth (MTD), coronal tibial slope (CTS), femoral notch width (NW), femoral condylar width (FCW), intercondylar notch depth (ND), femoral notch width index (NWI), intercondylar notch shape index (NSI), and cruciate ligaments tensity (CLT) were measured from magnetic resonance images. Anatomic characteristics differing between groups were compared, and risk factors for isolated meniscal injury were identified by multivariate forward stepwise logistic regression for men and women separately.

RESULTS

Risk factors for an isolated medial meniscal injury were a steeper MTS and a lowered MTD in men, and a steeper MTS and an increased NWI in women. Risk factors for isolated lateral meniscal injury were a steeper LTS and an increased NW in men, and a steeper LTS and a lowered ND in women. Risk factors for both medial and lateral meniscal injuries were a higher CTS, an increased NWI, and a looser CLT in men, and a higher CTS, an increased NSI, and a looser CLT in women.

CONCLUSION

The anatomic characteristics of the tibial plateau, femur, and cruciate ligaments influence the risk of suffering isolated meniscal injury, and the risk factors differ between men and women. This study provides a reference for developing identification criteria for those at risk of isolated meniscal injury.

LEVEL OF EVIDENCE

III.

Familial Risk and Its Interaction With Body Mass Index and Physical Activity in Anterior Cruciate Ligament Injury Among First-Degree Relatives: A Population-Based Cohort Study

BACKGROUND

Genetic and behavioral risk factors have been suggested to play a role in anterior cruciate ligament (ACL) injury. However, population-based familial risk estimates are unavailable.

PURPOSE

To quantify familial risk of ACL injury among first-degree relatives (FDRs) after controlling for certain behavioral risk factors. To estimate the combined effect of family history and body mass index (BMI) or physical activity on the risk of ACL injury.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Using nationwide data from the Korean National Health Insurance and National Health Screening Program databases on kinship, lifestyle habits, and anthropometrics, 5,184,603 individuals with blood-related FDRs were identified from 2002 to 2018. Familial risk of ACL injury, as represented as incidence risk ratios (IRRs) with 95% CIs, was analyzed using Cox proportional hazards models among individuals with versus without affected FDRs. Analyses were adjusted for age, sex, and behavioral risk factors. Interaction testing between familial history and BMI or physical activity was performed on an additive scale.

RESULTS

The risk of ACL injury was 1.79-fold higher (IRR, 1.79; 95% CI, 1.73-1.85) among individuals with versus without affected FDRs, and the incidence was 12.61 per 10,000 person-years. The IRR (95% CI) was highest with affected twins at 4.49 (3.01-6.69), followed by siblings at 2.31 (2.19-2.44), the father at 1.58 (1.49-1.68), and the mother at 1.52 (1.44-1.61). High BMI and high level of physical activity were significantly associated with the risk of ACL injury. Individuals with positive family history and either high BMI or physical activity had a 2.59- and 2.45-fold increased risk of injury as compared with the general population, respectively, and the combined risks exceeded the sum of their independent risks.

CONCLUSION

Familial factors are risk factors for ACL injury with an additional contribution of 2 behavioral factors: BMI and physical activity level. A significant interaction was observed between family history of ACL injury and high BMI/level of physical activity.

Medial meniscus ramp and lateral meniscus posterior root lesions are present in more than a third of primary and revision ACL reconstructions

PURPOSE

The purpose of this study was (1) to describe the meniscus tear pattern in anterior cruciate ligament (ACL)-injured patients, with a special focus on medial meniscus (MM) ramp lesions and lateral meniscus (LM) root tears and (2) to determine whether patient and injury characteristics were associated with meniscus tear patterns.

METHODS

Data from 358 cases of ACL primary and revision reconstruction surgeries were extracted from a center-based registry. During arthroscopy, the presence of associated meniscus lesions was documented by systematically inspecting the anterior and posterior tibiofemoral compartments. With a special focus on MM ramp lesions and LM root tears, groups of different injury tear patterns were formed. Chi-square tests were used to determine whether these groups differed with respect to various patient and injury characteristics, including gender, previous ipsilateral ACL injuries, the injury's relation to sport, person contact during injury and the type of ACL tear. Median age at surgery and body mass index were compared between groups using the Kruskal-Wallis test. Significance was set at p < 0.05.

RESULTS

Two hundred and thirty-nine ACL injuries (67%) showed additional meniscal injuries, of which 125 (52%) involved the MM ramp and/or the LM root. Ramp lesions were more frequent in males (23% vs 12% in females, p < 0.01), in contact injuries (28% vs 16% in non-contact, p < 0.05) and in complete ACL tears (21% vs 5% in partial, p < 0.05). Combined injuries of the MM ramp and the LM root showed a higher percentage of contact injuries compared to non-contact injuries (10% vs 4%, p < 0.05).

CONCLUSION

Two-thirds of all ACL injuries showed a concomitant meniscus injury, of which half involved the biomechanically relevant, but previously often undiagnosed RLMM or the PRLM. These findings provide evidence that until recently about half of ACL-associated meniscus injuries were not properly identified. Ramp lesions were more frequent in males, contact injuries and in complete ACL tears. These findings stress the need for a systematic assessment and a better understanding of the pathomechanism of these specific injuries which may have an important impact on knee biomechanics and the outcome of ACL reconstruction.

LEVEL OF EVIDENCE

III.