Femoral intercondylar notch stenosis and correlation to anterior cruciate ligament injuries. A prospective study

Notchplasty in anterior cruciate ligament reconstruction: A systematic review of clinical outcomes

Introduction

Notchplasty is an adjuvant procedure performed during Anterior Cruciate Ligament reconstruction (ACLR) with the purpose of widening the intercondylar notch of the femur. Its use is controversial due to its biomechanical influence on the knee and the potential for increased complications. The purpose of this systematic review is to evaluate the outcomes of patients who underwent ACLR with notchplasty.

Materials and methods

A systematic search of Cochrane, Embase, and Medline was conducted to identify papers evaluating clinical outcomes of patients who underwent ACLR with notchplasty. Inclusion criteria encompassed human studies with a control group, reporting clinical outcomes such as graft failure, graft rupture, range of motion values, and patient-reported outcomes.

Results

A total of 4 studies were included comprising 396 patients (129 with notchplasty, 235 without). No significant differences were reported regarding graft survivability or Lysholm score between those with notchplasty and those without. One study reported significantly reduced rates of revision surgery after ACLR with notchplasty. There were conflicting complication rates between studies regarding chronic synovitis and arthrofibrosis.

Conclusion

Patients who undergo notchplasty during primary ACLR have similar outcome scores and risk of graft failure compared to those who do not undergo notchplasty. Notchplasty patients may also be at a higher risk for loss of extension and chronic synovitis.

Lateral Extra-Articular Tenodesis With Iliotibial Band in Anterior Cruciate Ligament Autograft Reconstruction for Female Soccer Athletes With Generalized Ligamentous Laxity Yields Graft Failure and Return-to-Sport Rates Comparable With Athletes Without Generalized Laxity

PURPOSE

To evaluate the effectiveness of adding lateral extra-articular tenodesis (LET) to primary anterior cruciate ligament reconstruction (ACLR) in competitive female soccer athletes with greater preoperative generalized ligamentous laxity.

METHODS

A retrospective review of female high school and collegiate soccer players who underwent primary ACLR from 2013 to 2021, with a minimum of 2 years of follow-up, was conducted. Participants were divided into 2 groups: those who received ACLR alone and those who received ACLR with LET. Generalized ligamentous laxity was defined as a Beighton score ≥4 and was not considered an indication for LET. Anterior cruciate ligament (ACL) autografts included the quadriceps, bone-patellar tendon-bone, and hamstrings in both groups. Patient demographics and physical examination findings, including pivot shift results, were collected. Positive pivot-shift refers to a grade ≥2. Patient outcomes included graft failure (defined as ACL retear), International Knee Documentation Committee score, Lysholm score, return to sport, and complications. Independent t tests, χ2 tests, and Mann-Whitney U tests were conducted to compare outcomes between the 2 groups. Minimally clinical important difference was calculated from preoperative to final follow-up.

RESULTS

A total of 133 female soccer players who underwent ACLR met inclusion criteria, including 43 patients that received an ACLR + LET and 90 patients who underwent isolated ACLR. Average follow-up was 39.0 and 36.1 months in the LET group and the control group, respectively. Patients who underwent LET had a greater generalized ligamentous laxity rate (48.8% vs 18.9%; P < .001) and greater median Beighton score (3.0 vs 1.0; P < .001) than those without LET. There was a similar rate of graft failure in patients who underwent LET compared with the control group (4.7% vs 3.0%; P = .658). On the basis of minimally clinical important difference thresholds, there were no clinically relevant differences in International Knee Documentation Committee or Lysholm scores noted between the 2 groups. Return-to-sport rates also were comparable between the LET and control cohorts (90.7% vs 85.6%; P = .807).

CONCLUSIONS

The addition of LET during ACLR in female soccer players with preoperative generalized ligamentous laxity yields graft retear and return-to-sport rates comparable with those of athletes without ligamentous laxity.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Morphological changes to the intercondylar space in different stages of osteoarthritis - A retrospective cross-sectional study

BACKGROUND

The intercondylar space is defined as the topographic area walled by the intercondylar notch (IN) and encasing the central ligaments of the knee joint. As the anterior cruciate ligament (ACL) is not only impinged against the roof but also against the lateral wall of the IN, information concerning changes to the IN during the progression of osteoarthritis could be potentially relevant in predicting the future risk for ACL-rupture and -degeneration and ensure preventive measures as early as possible. Therefore, the purpose of this study was to evaluate the influence of osteoarthritis on osseous notch morphology.

METHODS

Image data was retrieved from the Osteoarthritis Initiative. Patients were subdivided into five groups according to the severity of osteoarthritis following the Kellgren and Lawrence classification. 415 patients were selected randomly to ensure equally large groups. Osseous structures were measured in coronal and axial planes in MRI. At the level of the popliteal groove and on the level of the joint line, the width of the lateral and medial femoral condyle, the notch width (NW) as well as the total width of the distal femur were measured. The notch width index (NWI) as ratio between the NW and the total width of the distal femur was calculated. Three shapes (A-shape, Inverse-U-shape and Ω-shape) of the IN were differentiated.

RESULTS

The morphology of the IN is directly influenced by the development of osteoarthritis. Especially the Ω-shape is characteristic for more severe cases of osteoarthritis (p < 0.001). Measurements were also significantly influenced by the imaging plane and the level of measurements (both p < 0.001).

CONCLUSIONS

The results of this study reflect significant changes to the intercondylar space in increasing grades of osteoarthritis. Additionally, the recommendation on the location of measurements of the IN should be revised, as especially the measurements on the level of the joint line in coronal plane MRI are a more reliable and objective indicator for the diagnosis of IN stenosis and therefore of changes to the intercondylar space, which always influences the health of the ligaments housed. At the level of the popliteal groove a NWI< 0.25 and NW< 19 mm and at the level of the joint line a NWI< 0.17 and a NW< 14 mm should be interpreted as severe notch stenosis and a definitive risk factor for ACL rupture.

Injury Prevention Strategies in Female Football Players: Addressing Sex-Specific Risks

There has been rapid growth in women's football worldwide; however, research on injury prevention strategies and physiological considerations specific to female athletes remains insufficient. Women's football has experienced an increase in injury prevalence, despite being underrepresented in sports literature, with less than 25% of research focused on this demographic. The incidence of injuries, particularly among young elite female footballers, is notably high, impacting long-term health outcomes such as osteoarthritis and contributing to shorter playing careers. Certain injuries, such as anterior cruciate ligament (ACL) ruptures, occur at significantly higher rates in women compared to men, underscoring sex-specific risk factors that must be addressed in injury prevention programs (IPPs). This narrative review aims to evaluate the effectiveness of IPPs tailored for female football players and to address their heightened susceptibility to injuries compared to males. Research studies and review articles were identified using a literature search of the PubMed, SportDiscus, and Google Scholar databases from 1990 to December 2024. Biological factors, including hormonal influences-such as increased ACL laxity during the menstrual cycle-and musculoskeletal differences, such as muscle strength imbalances, reduced joint stability, and hip weakness, significantly contribute to this increased risk. Despite the existence of injury prevention protocols like FIFA 11+, their consistent application and adaptation to meet the unique needs of female footballers remain limited. In addition to physical injuries, mental health is a critical concern. Female football players exhibit higher rates of depression and anxiety compared to their male counterparts, influenced by factors such as injury-related stress and menstrual cycle variations. In conclusion, the growing participation of women in football highlights the urgent need for research and implementation of injury prevention strategies specifically tailored to female players.

Combined Anterior Cruciate Ligament and Anterolateral Ligament Reconstruction Shows Superior Graft Remodeling, Maturation, and Stability Compared With Isolated Anterior Cruciate Ligament Reconstruction

PURPOSE

To compare graft remodeling, as measured by magnetic resonance imaging (MRI), and clinical outcomes between patients who underwent isolated anterior cruciate ligament reconstruction (ACLR) versus combined anterior cruciate ligament and anterolateral ligament reconstruction (ACLR + ALLR).

METHODS

A retrospective review was conducted on patients who underwent primary ACLR with quadruple hamstring grafts between January 2019 and March 2022, with a minimum follow-up period of 2 years. Patients were categorized into two groups based on the addition of ALLR with tibialis anterior allografts: an isolated ACLR group and an ACLR + ALLR group. Graft ligamentization was assessed using signal-to-noise quotient (SNQ) values obtained from postoperative MRI scans, with lower SNQ values indicating superior graft remodeling. Clinical outcomes were evaluated through knee stability tests (pivot-shift test, side-to-side laxity), functional outcomes, and graft retear rates. The minimal clinically important difference (MCID) for the clinical scores was calculated using the distribution-based method of a half standard deviation of the delta (difference between postoperative and baseline values). Regression analyses identified potential predictive factors for inferior ACL graft remodeling.

RESULTS

A total of 122 patients in the isolated ACLR group and 54 in the ACLR + ALLR group were evaluated. The mean follow-up periods were similar between the groups (34.1 ± 7.4 months vs 36.4 ± 9.0 months; P = .755). The mean SNQ values were significantly lower in the ACLR + ALLR group compared to the isolated ACLR group (2.8 ± 1.6 vs 4.7 ± 3.5 mm, respectively; P = .001). Inferior ACL graft maturity was associated with an increased posterior tibial slope (P = .016), narrow notch width (P =.018), and concomitant medial meniscal lesion (P = .017). At the final evaluation, the ACLR + ALLR group demonstrated better rotational stability as indicated by the residual pivot-shift test (P = .005). No statistically significant differences were observed between the two groups in side-to-side laxity, functional outcomes, or graft retear rates. There were no differences in the percentage of patients achieving MCID for the International Knee Documentation Committee subjective score between the groups (P = .536).

CONCLUSIONS

Combined ACLR and ALLR resulted in superior graft remodeling, demonstrated by a mean SNQ value that was 1.9 lower than in isolated ACLR, along with improved rotational stability.

LEVEL OF EVIDENCE

Level III, retrospective, nonrandomized, comparative therapeutic study.

Biophysics of ACL Injuries

Anterior Cruciate Ligament (ACL) injuries rank among the most prevalent and severe types of injuries, significantly impacting both athletes and non-athletes alike. These injuries not only result in immediate physical impairment, such as intense pain, substantial swelling, and a marked loss of mobility, but also carry long-term health consequences that can alter a person's quality of life. Chronic pain, persistent instability, and an increased risk of developing osteoarthritis are among the lasting effects that can follow an ACL injury. An in-depth understanding of the biophysics behind ACL injuries is paramount for devising effective prevention and treatment protocols. Biophysics, which combines principles from physics with biological systems, provides crucial insights into the mechanical and structural integrity of the ACL and its susceptibility to injury under various conditions. This systematic review aims to collate and synthesize the current knowledge surrounding the biophysical mechanisms that underlie ACL injuries.

Decreased sagittal slope of the medial tibial spine and deep concavity of the lateral tibial spine are risk factors for noncontact anterior cruciate ligament injury

PURPOSE

This study aimed to assess the relationship between the geometric features of tibial eminence and susceptibility to noncontact anterior cruciate ligament (ACL) injuries.

METHODS

Patients with unilateral noncontact knee injuries between 2015 and 2021 were consecutively enroled in this study. Based on knee magnetic resonance imaging (MRI) and arthroscopic visualisation, patients were categorised into the case group (ACL rupture) and control group (ACL intact). Using MRI, the geometric features of tibial eminence were characterised by measuring the sagittal slopes, depth of concavity and coronal slopes of the inclined surfaces of the tibial spines. Univariate and multivariate logistic regressions were conducted to explore independent associations between quantified geometric indices of tibial eminence and the risk of noncontact ACL injuries.

RESULTS

This study included 187 cases and 199 controls. A decreased sagittal slope of the medial tibial spine (MTSSS) (combined group: odds ratio [OR]: 0.87 [0.82, 0.92], p < 0.001; females: OR: 0.88 [0.80, 0.98], p = 0.020; males: OR: 0.87 [0.81, 0.93], p < 0.001) and an increased depth of concavity in the lateral tibial spine (LTSD) (combined group: OR: 1.51 [1.24, 1.85], p < 0.001; females: OR: 1.65 [1.12, 2.43], p = 0.012; males: OR: 1.44 [1.11, 1.89], p = 0.007) were independent risk factors for noncontact ACL injuries. Moreover, a steeper coronal slope of the inclined surface of the medial tibial spine was a significant predictor of noncontact ACL injuries for males (MTSCS: OR: 1.04 [1.01, 1.08], p = 0.015) but not for females.

CONCLUSION

Geometric features of tibial eminence, particularly a decreased MTSSS and an increased LTSD, were identified as independent risk factors for noncontact ACL injuries. These findings will help clinicians identify individuals at high risk of ACL injury and facilitate the development of targeted prevention strategies.

LEVEL OF EVIDENCE

Level III.

Excessive Knee Internal Rotation during Grand Plié in Classical Ballet Female Dancers

Classical ballet dancers are exposed daily to physically demanding movements. Among these, the Grand Plié stands out for its biomechanical complexity, particularly the stress applied to the knee joint. This study investigates the knee kinematics of healthy professional classical ballet dancers performing the Grand Plié. Twenty dancers were evaluated with a motion analysis system using a marker-based protocol. Before measurements, the self-reported Global Knee Functional Assessment Scale was delivered for the knees' functional ability, and the passive range of knee motion was also assessed. The average score on the Global Knee Functional Assessment Scale was 94.65 ± 5.92. During a complete circle of the Grand Plié movement, executed from the upright position, the average maximum internal rotation of the knee joint was 30.28° ± 6.16°, with a simultaneous knee flexion of 134.98° ± 4.62°. This internal rotation observed during knee flexion exceeds the typical range of motion for the joint, suggesting a potential risk for knee injuries, such as meniscal tears. The findings provide an opportunity for future kinematic analysis research, focusing on the movement of the Grand Plié and other common ballet maneuvers. These data have the potential to yield valuable information about the knee kinematics concerning meniscus damage.

Effects of peak ankle dorsiflexion angle on lower extremity biomechanics and pelvic motion during walking and jogging

Objective

Ankle dorsiflexion during walking causes the tibia to roll forward relative to the foot to achieve body forward. Individuals with ankle dorsiflexion restriction may present altered movement patterns and cause a series of dysfunction. Therefore, the aim of this research was to clearly determine the effects of peak ankle dorsiflexion angle on lower extremity biomechanics and pelvic motion during walking and jogging.

Method

This study involved 51 subjects tested for both walking and jogging. The motion capture system and force measuring platforms were used to synchronously collect kinematics and kinetics parameters during these activities. Based on the peak ankle dorsiflexion angle during walking, the 51 subjects were divided into a restricted group (RADF group, angle <10°) and an ankle dorsiflexion-unrestricted group (un-RADF group, angle >10°). Independent-Sample T-tests were performed to compare the pelvic and lower limb biomechanics parameters between the groups during walking and jogging test on this cross-sectional study.

Results

The parameters that were significantly smaller in the RADF group than in the un-RADF group at the moment of peak ankle dorsiflexion in the walking test were: ankle plantar flexion moment (p < 0.05), hip extension angle (p < 0.05), internal ground reaction force (p < 0.05), anterior ground reaction force (p < 0.01), pelvic ipsilateral tilt angle (p < 0.05). In contrast, the external knee rotation angle was significantly greater in the RADF group than in the un-RADF group (p < 0.05). The parameters that were significantly smaller in the RADF group than in the un-RADF group at the moment of peak ankle dorsiflexion in the jogging test were: peak ankle dorsiflexion angle (p < 0.01); the anterior ground reaction force (p < 0.01), the angle of pelvic ipsilateral rotation (p < 0.05).

Conclusion

This study shows that individuals with limited ankle dorsiflexion experience varying degrees of altered kinematics and dynamics in the pelvis, hip, knee, and foot during walking and jogging. Limited ankle dorsiflexion alters the movement pattern of the lower extremity during walking and jogging, diminishing the body's ability to propel forward, which may lead to higher injury risks.

Intercondylar notch width and osteophyte width impact meniscal healing and clinical outcomes following transtibial pullout repair of medial meniscus posterior root tears

PURPOSE

This retrospective study aimed to investigate the relationship between intercondylar notch width (ICNW), osteophyte width (OW), and the healing of medial meniscus posterior root tears (MMPRTs) following arthroscopic pullout repair.

METHODS

The study included 155 patients diagnosed with MMPRTs who underwent transtibial pullout repair. Meniscal healing status was evaluated on second-look arthroscopy using a previously reported meniscus healing score. Patients were divided into two groups based on this score: the high healing score (group HH, healing score ≥ 8 points) and suboptimal healing score (group SO, healing score ≤ 6 points) groups. Computed tomography scans were performed on patients 1 week postsurgery. ICNW and OW widths were measured and relatively evaluated based on their ratio to the intercondylar distance (ICD), represented as the ICNW/ICD ratio (%) and OW/ICD ratio (%), respectively. Patient-reported outcomes were assessed preoperatively and on second-look arthroscopy using the Knee injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS).

RESULTS

There were no significant demographic differences between the SO and HH group (n = 35 and 120 patients, respectively). Regarding radiographic measurements, significant differences were observed in the ICNW/ICD ratio (group SO, 24.2%; group HH, 25.2%; p = 0.024), OW (group SO, 2.6 mm; group HH, 2.0 mm; p < 0.001), and OW/ICD ratio (group SO, 3.5%; group HH, 2.7%; p < 0.001). Both groups had similar preoperative clinical scores, but postoperative clinical scores, including KOOS-activities of daily living (group SO, 83.4; group HH, 88.7; p = 0.035) and VAS (group SO, 19.1; group HH, 11.3; p = 0.005), were significantly better in group HH.

CONCLUSION

The study suggests that ICNW and OW may play a crucial role in MMPRT healing following arthroscopic pullout repair, as evidenced by the worse clinical outcomes associated with a narrower ICNW and wider OW. These findings highlight the potential significance of ICNW and OW assessments when evaluating meniscal repair indications.

LEVEL OF EVIDENCE

Level III.

Vertical Stenosis as a Morphological Risk Factor for Anterior Cruciate Ligament Ruptures in Children: A Magnetic Resonance Imaging-Based Comparison

BACKGROUND

There are known anatomic variations that may lead to traumatic disruption of the anterior cruciate ligament (ACL) identified within adult and adolescent patients.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the parameters of pediatric knees diagnosed with and without an ACL injury by magnetic resonance imaging. The hypothesis was that children with ACL abnormalities would demonstrate an equivalent notch width index (NWI), but a larger notch height index (NHI), in comparison with age-matched patients without ACL abnormalities, suggesting an association with congenital morphology.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective comparison cohort study of pediatric knees was performed by evaluating those with a confirmed ACL rupture/deficiency and those with a benign diagnosis on magnetic resonance imaging. Overall, 6 osseous and cartilaginous measurements and 3 ratios (2 newly described) were determined. They were then grouped for statistical purposes by age: children aged 5 to 11 years and adolescents aged 12 to 19 years.

RESULTS

A total of 119 (49 children) consecutive patients with an ACL injury and 139 (72 children) healthy patients met inclusion criteria. The interaction between ACL status and age was significant for condylar measurements (P≤ .001), tibial spine height (P = .003), vertical space above tibial spine (P≤ .001), and NWI (P≤ .001) by 2-way analysis of variance. Although the NHI (P < 0.001) and tibial spine prominence (P = 0.039) demonstrated stenosis in the adolescent group, they did not have significant interactions with age and ACL status (P > 0.05). Regarding the transcondylar width, only the children's group had a significant difference regarding ACL status (P < .001), and the mean values in the children's group with ACL tears were nearly identical to those in the adolescent group both with and without ACL tears. The children's group with ACL tears also had a significantly larger tibial spine height compared with healthy children (P < .001).

CONCLUSION

Children, similar to adolescents, demonstrated the effect of the NWI on the risk of ACL tears, but only the adolescent group demonstrated stenosis with the NHI. The morphology of the knee in a child at risk for ACL rupture was not the same as that of an adolescent when considering all dimensions, but it did seem that it was more adolescent-like than child-like at the time of an ACL rupture, refuting the idea of congenital hypoplasia as a common cause.

Development of Anatomic Risk Factors for ACL Injuries: A Comparison Between ACL-Injured Knees and Matched Controls

BACKGROUND

Several tibiofemoral anatomic features have been repeatedly associated with increased anterior cruciate ligament (ACL) injury risk. Previous studies have highlighted age and sex differences among these anatomic risk factors, but little is known about the normal and pathologic development of these differences during skeletal maturation.

PURPOSE

To investigate differences in anatomic risk factors at various stages of skeletal maturation between ACL-injured knees and matched controls.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

After institutional review board approval, magnetic resonance imaging scans from 213 unique ACL-injured knees (age, 7-18 years, 48% female) and 239 unique asymptomatic ACL-intact knees (age, 7-18 years, 50% female) were used to measure femoral notch width, posterior slope of the lateral and medial tibial plateau, medial and lateral tibial spinal height (MTSH, LTSH), medial tibial depth, and posterior lateral meniscus-bone angle. Linear regression was performed to assess change in quantified anatomic indices with age for male and female patients in the ACL-injured cohort. Two-way analysis of variance with Holm-Sidak post hoc testing was performed to compare anatomic indices between ACL-injured knees and ACL-intact controls in each age group.

RESULTS

In the ACL-injured cohort, notch width, notch width index and medial tibial depth increased with age (R2 > 0.1; P < .001) in both sexes. MTSH and LTSH increased with age only in boys (R2≥ 0.09; P≤ .001), whereas meniscus-bone angle decreased with age only in girls (R2 = 0.13; P < .001). There were no other age differences in quantified anatomic indices. Patients with ACL injury consistently had a significantly higher lateral tibial slope (P < .01) and smaller LTSH (P < .001) as compared with ACL-intact controls across all age groups and sexes. When compared with age- and sex-matched ACL-intact controls, ACL-injured knees had a smaller notch width (boys, 7-18 years; girls, 7-14 years; P < .05), larger medial tibial slope (boys and girls, 15-18 years; P < .01), smaller MTSH (boys, 7-14 years; girls, 11-14 years; P < .05), and larger meniscus-bone angle (girls, 7-10 years; P = .050).

CONCLUSION

The consistent morphologic differences throughout skeletal growth and maturation suggest a developmental role in high-risk knee morphology. The observed high-risk knee morphology at an earlier age preliminarily suggests the potential of knee anatomy measurements in identifying those with a predisposition toward ACL injury.

Effect of demographic features on morphometric variables of the knee joint: Sample of a 20 to 40-year-old Turkish population

This study aimed to investigate the relationship between body mass index (BMI), age, and sex and morphological risk factors that may cause internal knee injuries. The magnetic resonance images of 728 participants who met the inclusion criteria and had a mean age of 34.4 ± 6.8 years were analyzed retrospectively. Demographic differences were analyzed by measuring 17 morphological parameters known to be associated with internal knee injuries. Men had a higher anterior cruciate ligament length (ACLL), anterior cruciate ligament width, (ACLW) lateral femoral condylar width (LFCW), medial femoral condylar width (MFCW), lateral femoral condylar depth (LFCD), distal femoral width (DFW), and intercondylar femoral width (IFW) than women (P < .05). By contrast, the medial meniscus bone angle (MMBA) was lower in men than in women (P < .05). Women aged 31 to 40 years had a lower Insall-Salvati index (ISI) and lateral tibial posterior slope (LTPS) than those aged 21 to 30 years (P < .05), whereas men aged 31 to 40 years had a lower ISI than those aged 21 to 30 years (P < .05). Women with BMI ≥ 30 had a higher LFCW and MFCW but a lower ISI than those with BMI < 30 (P < .05). Men with BMI ≥ 30 had a higher LFCW, MFCW, DFW, and MMBA than those with BMI < 30 (P < .05). The use of value ranges structured according to demographic characteristics, rather than a single value range for all patient groups, may contribute to the evaluation and treatment of the morphological features that are thought to be effective in the development of internal knee injuries. These values may also shed light on future radiological risk scoring systems and artificial intelligence applications in medicine.

Assessment Of Femoral Notch Morphology In Male Patients With Anterior Cruciate Ligament Injury: An MRI Study

Aim: The objective of the present study was to evaluate the femoral notch type, notch width index (NWI), notch angle (NA) and α angle in patients with ACL injury and compare with nonathletic male population using magnetic resonance imaging (MRI). Methods: 79 patients with complete ACL tear and 80 patients as control group (aged 19-43 years) who had knee MRI were evaluated. NWI, NA measurements and notch shape were evaluated on axial fat-saturated proton-weighted sequences. Femoral notch shape was classified as A, U and W types. Results: A statistically significant association was found between notch type, NWI, NA and ACL injury (p

Consensus Delphi study on guidelines for the assessment of anterior cruciate ligament injuries in children

Background: Knee examination guidelines in minors are intended to aid decision-making in the management of knee instability. Clinical question: A Delphi study was conducted with a formal consensus process using a validated methodology with sufficient scientific evidence. A group consensus meeting was held to develop recommendations and practical guidelines for use in the assessment of instability injuries in children. Key findings: there is a lack of evidence to analyse anterior cruciate ligament injuries in children and their subsequent surgical management if necessary. Diagnostic guidelines and clinical assessment of the patient based on a thorough examination of the knee are performed and a guide to anterior cruciate ligament exploration in children is developed. Clinical application: In the absence of a strong evidence base, these established guidelines are intended to assist in that decision-making process to help the clinician decide on the most optimal treatment with the aim of benefiting the patient as much as possible. Following this expert consensus, surgical treatment is advised when the patient has a subjective sensation of instability accompanied by a pivot shift test ++, and may include an anterior drawer test + and a Lachman test +. If these conditions are not present, the conservative approach should be chosen, as the anatomical and functional development of children, together with a physiotherapy programme, may improve the evolution of the injury.

Narrow Notch Width and Low Anterior Cruciate Ligament Volume Are Risk Factors for Anterior Cruciate Ligament Injury: A Magnetic Resonance Imaging-Based Study

BACKGROUND

The relationship between anterior cruciate ligament (ACL) injury and anatomical structures is still a topic of debate.

PURPOSE

The aim of this study was to compare knee geometry in demographically matched ACL-injured and ACL-intact athletes.

METHODS

We conducted a case-control study comparing 2 groups, each consisting of 55 professional athletes (44 men and 11 women): 1 group with complete ACL tears (cases) and 1 group with intact ACLs (controls). The groups were compared using magnetic resonance imaging (MRI) in terms of intercondylar notch geometry, tibial plateau characteristics, and ACL volume.

RESULTS

Among cases and controls, we found the cases had lower notch width (20.24 ± 2.68 mm vs. 22.04 ± 2.56 mm, respectively) and notch width index (0.29 ± 0.03 vs. 0.31 ± 0.03, respectively). The mean ACL volume in the cases (1181.63 mm³ ± 326 mm³) was also lower than in controls (1352.61 mm³ ± 279.84 mm³). The parameters of tibial slope geometry were comparable between groups. In addition, women had lower ACL volume than men (1254 ± 310 mm³ vs. 890 ± 267 mm³, respectively) and higher medial posterior tibial slope (4.76 ± 2.6 vs. 6.63 ± 1.83, respectively). Among cases, women had narrower notch width than men (16.9 ± 2.42 mm vs. 21.08 ± 2.03 mm). However, notch width index was comparable between male (0.3 ± 0.02) and female (0.28 ± 0.03) cases.

CONCLUSION

Our findings suggest that narrow notch width and low ACL volume may enhance the risk of ACL injury among athletes. There was no association found between posterior tibial slope and ACL injury between athletes with injured ACLs and controls. Further study is indicated.

Notchplasty is associated with decreased risk of anterior cruciate ligament graft revision

PURPOSE

Despite influencing knee biomechanics and outcomes, the use of notchplasty at time of anterior cruciate ligament reconstruction (ACLR) has not been evaluated with regards to risk of secondary injury and revision. This study evaluates this association.

METHODS

42 patients (21.7-years, IQR = 19.0-27.5) that underwent primary then revision ACLR at a single institution were contrasted with a case matched control group of patients with grafts that did not fail. Patients were propensity score matched in a 1:2 ratio by age, gender, and date of index procedure. Post-hoc statistical correction was made for post-index procedure sports participation level.

RESULTS

Notchplasty was performed in 2 of 42 cases that went on to revision, and in 31 of 84 cases in the control group (p < 0.001). This was associated with reduced rates of revision ACLR (OR = 0.085, 95%CI = 0.019-0.378). A significant difference was seen in the post-ACLR activity level between groups (p = 0.028), with post-hoc testing highlighting those returning to competitive sport to be more likely to require subsequent revision (OR = 9.647, 95%CI = 1.947-47.795). Notchplasty remained significantly associated with (reduced) risk of revision surgery, despite the observed variation in post-ACLR activity (p = 0.001).

CONCLUSION

Individuals whose graft failed following ACLR were significantly less likely to have had notchplasty performed as part of their surgery than a control group who did not suffer graft reinjury. We propose that this may be due to decreased tensioning of the graft as the knee enters dynamic valgus, which may be of great relevance to athletes undergoing ACLR to enable return to sport.

Anatomical Risk Factors for Anterior Cruciate Ligament Injury Are Not Important As Patellar Instability Risk Factors in Patients with Acute Knee Injury

To compare in magnetic resonance imaging the anatomical risk factors for anterior cruciate ligament (ACL) injury and patellar dislocation among patients who suffered acute knee injury, 105 patients with acute knee injury resulting in 38 patellar dislocations (patella group), 35 ACL injuries (ACL group), and 32 meniscus or medial collateral ligament injuries (control group) were included. These groups were compared for risk factors for patellar dislocation (patellar height, trochlear dysplasia, and quadriceps angle of action) and for ACL injury (intercondylar width, posterior inclination of tibial plateaus, and depth of the medial plateau). Univariate analysis found statistically significant differences (p < 0.05) between the patella and ACL groups in patellar height (Caton-Deschamps [CD] 1.23 vs. 1.07), trochlear facet asymmetry (55 vs. 68%), PTTG (13.08 vs. 8.01 mm), and the patellar tip and trochlear groove (PTTG) angle (29.5 vs. 13.71 degrees). The patella group also differed from control in medial plateau inclination (4.8 vs. 1.87 degrees), patellar height (CD 1.23 vs 1.08), trochlear facet asymmetry (55 vs. 69%), lateral trochlear inclination (17.11 vs. 20.65 degrees), trochlear depth (4.1 vs. 6.05 mm), PTTG (13.08 vs. 9.85 mm), and the PTTG angle (29.5 vs. 17.88 degrees). The ACL and control groups were similar in all measures. Multivariate analysis found the following significant determinants between the Patella and Control groups: patellar height (CD index, odds ratio [OR]: 80.13, p = 0.015), trochlear anatomy (asymmetry of facets M/L, OR: 1.06, p = 0.031) and quadriceps action angle (PTTG angle, OR: 1.09, p = 0.016); between the ACL and control groups: PTTG angle (OR: 0.936, p = 0.04) and female gender (OR: 3.876, p = 0.032); and between the patella and ACL groups, the CD index (OR: 67.62, p = 0.026), asymmetry of the M/L facets (OR: 1.07, p = 0.011) and PTTG angle (OR: 1.16, p < 0.001). In conclusion, in patients with acute knee injury, the anatomical factors patellar height, trochlear dysplasia, and quadriceps angle of action were related to the occurrence of patellar dislocation. None of the anatomical factors studied was related to the occurrence of anterior cruciate ligament injury.

The geometric features of tibiofemoral joint associated with anterior cruciate ligament injury: Reliability of measurements on conventional MRI

Purpose

To evaluate the measurement reliability of the geometric features of tibiofemoral joint on conventional knee MRI and also identify the features associated with increased risk of ACL injury.

Methods

This retrospective case-control study included knee MRIs of 60 patients with ACL injury (34 men, 26 women; mean age 34 ± 13.6 SD) and 60 normal individuals (31 men, 29 women; mean age 36 ± 11.4 SD). Geometric features of distal femur (intercondylar notch width, transcondylar width, and intercondylar notch angle) and tibial plateau (medial tibial plateau slope, lateral tibial plateau slope, and medial tibial plateau depth) were independently measured by two radiologists for each of the patients. Intraclass correlation coefficient (ICC) values were calculated to assess the reliability of the measurements. Variables with acceptable ICC values were included in the final logistic regression model, but the remaining were only reported descriptively.

Results

There was good to excellent agreement between the radiologist in the measurement of ICNW and TCW. However, the agreement between the radiologists was not acceptable for the rest of the variables. The univariate logistic regression model showed as ICNW decreases, the risk of ACL injury increases (OR = 0.12, 95% CI [0.02, 0.60], p = 0.01).

Conclusions

Our results suggest that ICNW and TCW are the only geometric features of the tibiofemoral joint that can be reliably measured on conventional knee MRI. Moreover, decreased ICNW is associated with an increased risk of ACL injury.

Medial and Lateral Posterior Tibial Slope in the Skeletally Immature: A Cadaveric Study

Background:

An increased posterior tibial slope (PTS) results in greater force on the anterior cruciate ligament (ACL) and is a risk factor for ACL injuries. Biomechanical studies have suggested that a reduction in the PTS angle may lower the risk of ACL injuries. However, the majority of these investigations have been in the adult population.

Purpose:

To assess the mean medial and lateral PTS on pediatric cadaveric specimens without known knee injuries.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 39 pediatric knee specimens with computed tomography scans were analyzed. Specimens analyzed were between the ages of 2 and 12 years. The PTS of each specimen was measured on sagittal computed tomography slices at 2 locations for the medial and lateral angles. The measurements were plotted graphically by age to account for the variability in development within age groups. The anterior medial and lateral tibial plateau widths were measured. The distance between the top of the tibial plateau and the physis was measured. The independent-samples t test and analysis of variance were used to analyze the measurements.

Results:

The mean PTS angle for the medial and lateral tibial plateaus was 5.53° ± 4.17° and 5.95° ± 3.96°, respectively. The difference between the PTS angles of the medial and lateral tibial plateaus was not statistically significant (P > .05). When plotted graphically by age, no trend between age and PTS was identified.

Conclusion:

This data set offers values for the PTS in skeletally immature specimens without a history of ACL injury and suggests that age may not be an accurate predictive factor for PTS.

Disparities in ACL Reconstruction: the Influence of Gender and Race on Incidence, Treatment, and Outcomes

PURPOSE OF REVIEW

Anterior cruciate ligament (ACL) rupture is a common injury that has important clinical and economic implications. We aimed to review the literature to identify gender, racial and ethnic disparities in incidence, treatment, and outcomes of ACL injury.

RECENT FINDINGS

Females are at increased risk for ACL injury compared to males. Intrinsic differences such as increased quadriceps angle and increased posterior tibial slope may be contributing factors. Despite lower rates of injury, males undergo ACL reconstruction (ACLR) more frequently. There is conflicting evidence regarding gender differences in graft failure and ACL revision rates, but males demonstrate higher return to sport (RTS) rates. Females report worse functional outcome scores and have worse biomechanical metrics following ACLR. Direct evidence of racial and ethnic disparities is limited, but present. White athletes have greater risk of ACL injury compared to Black athletes. Non-White and Spanish-speaking patients are less likely to undergo ACLR after ACL tear. Black and Hispanic youth have greater surgical delay to ACLR, increased risk for loss to clinical follow-up, and less physical therapy sessions, thereby leading to greater deficits in knee extensor strength during rehabilitation. Hispanic and Black patients also have greater risk for hospital admission after ACLR, though this disparity is improving. Females have higher rates of ACL injury with inconclusive evidence on anatomic predisposition and ACL failure rate differences between genders. Recent literature has suggested inferior RTS and functional outcomes following ACLR in females. Though there is limited and mixed data on incidence and outcome differences between races and ethnic groups, recent studies suggest there may be disparities in those who undergo ACLR and time to treatment.

Sexual Dimorphisms in Anterior Cruciate Ligament Injury: A Current Concepts Review

Background:

Although most anterior cruciate ligament (ACL) injuries occur in male athletes, female athletes are consistently observed to be at a higher risk for sports-specific ACL injury.

Purpose:

To provide a thorough review of what is known about the sexual dimorphisms in ACL injury to guide treatment and prevention strategies and future research.

Study Design:

Narrative review.

Methods:

We conducted a comprehensive literature search for ACL-related studies published between January 1982 and September 2017 to identify pertinent studies regarding ACL injury epidemiology, prevention strategies, treatment outcomes, and dimorphisms. By performing a broad ACL injury search, we initially identified 11,453 articles. After applying additional qualifiers, we retained articles if they were published in English after 1980 and focused on sex-specific differences in any of 8 different topics: sex-specific reporting, difference in sports, selective training, hormonal effects, genetics, neuromuscular and kinematic control, anatomic differences, and outcomes.

Results:

A total of 122 articles met the inclusion criteria. In sum, the literature review indicated that female athletes are at significantly higher risk for ACL injuries than are their male counterparts, but the exact reasons for this were not clear. Initial studies focused on intrinsic differences between the sexes, whereas recent studies have shifted to focus on extrinsic factors to explain the increased risk. It is likely both intrinsic and extrinsic factors contribute to this increased risk, but further study is needed. In addition to female patients having an increased risk for ACL injuries, they are less likely than are male patients to undergo reconstructive surgery, and they experience worse postsurgical outcomes. Despite this, reconstructive surgery remains the gold standard when knee stability, return to sports, and high functional outcome scores are the goal, but further research is needed to determine why there is disparity in surgical rates and what surgical techniques optimize postsurgical outcomes for female patients.

Conclusion:

Male athletes often predominated the research concerning ACL injury and treatment, and although sex-specific reporting is progressing, it has historically been deficient. ACL injuries, prevention techniques, and ACL reconstruction require further research to maximize the health potential of at-risk female athletes.

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.

Analysis of intercondylar notch size and shape in patients with cyclops syndrome after anterior cruciate ligament reconstruction

Background

Cyclops lesion is the second most common cause of extension loss after anterior cruciate ligament reconstruction. This study focused on the correlation between the anatomy of the intercondylar notch and the incidence of cyclops lesion. To determine whether the size and shape of the intercondylar notch are related to cyclops lesion formation following anterior cruciate ligament reconstruction according to magnetic resonance imaging (MRI) findings.

Methods

One hundred twenty-five (125) patients were retrospectively evaluated. The notch width index (NWI) and notch shape index (NSI) were measured based on coronal and axial MRI sections in patients diagnosed with cyclops syndrome (n = 25), diagnosed with complete anterior cruciate ligament (ACL) tears (n = 50), and without cyclops lesions or ACL ruptures (n = 50).

Results

Imaging analysis results showed that the cyclops and ACL groups had lower mean NWI and NSI values than the control group. Significant between-group differences were found in NSI (p = 0.0140) based on coronal cross-sections and in NWI (p = 0.0026) and NSI (p < 0.0001) based on axial sections.

Conclusions

The geometry of the intercondylar notch was found to be associated with the risk of cyclops lesion formation and ACL rupture.

Cranial Cruciate Ligament Rupture in Dogs: Review on Biomechanics, Etiopathogenetic Factors and Rehabilitation

Cranial cruciate ligament (CrCL) rupture is one of the most common orthopaedic conditions in veterinary medicine. CrCL plays a fundamental role in the stability and biomechanics of the femoral-tibio-patellar joint, and its incorrect functionality severely impacts on the quality of life of patients. In dogs, the structural weakening of this joint due to the progressive degeneration of the ligament is the most accredited etiopathogenetic hypothesis in relation to the dog signalment (breed, sex and age) and the stifle joint conformation. In humans, this injury is often traumatic and generally occurs during sporting activities. CrCL rupture can be managed conservatively or surgically, and decisions regarding treatment are due to numerous factors: the patient’s age and health, the degree of stifle instability, and cost. Physiotherapy protocols play an important role in rehabilitation, with similar goals in humans and dogs: pain management, physiological articular range of motion recovery, periarticular and core muscle strengthening, and proprioceptive deficit correction. Physiotherapy, even if often neglected in veterinary medicine, is mandatory for the recovery of the correct functionality of the injured limb and for the return to normal daily and sporting activities.

Increased lateral femoral condyle ratio is associated with greater risk of ALC injury in non-contact anterior cruciate ligament injury

PURPOSE

To examine whether increased lateral femoral condyle ratio (LFCR) correlates with increased risk of Anterior cruciate ligament (ACL) injury (1) and to evaluate the relationship between the LFCR and anterolateral complex (ALC) injury in non-contact ACL torn knees (2).

METHODS

Six hundred and seventy-two patients who underwent ACL reconstruction surgery between 2013 and 2019 were retrospectively reviewed, and 120 patients were finally included in the study. Forty patients (ACL + ALC injury) were included in the study group, while forty patients with isolated ACL injury (isolated ACL injury group) and 40 patients who suffered from meniscal tear without ACL or ALC injury were matched in a 1:1 fashion by age, sex, and BMI to the study group (ACL + ALC injury). The LFCR was measured on standard lateral radiographs in a blinded fashion. The differences between the three groups were analyzed by ANOVA. A ROC (Receiver Operating Characteristic) curve was produced to determine risk of ACL injury and risk of concomitant ALC injury in non-contact ACL injury.

RESULTS

The mean LFCR was 71.9% ± 3.1% in the ACL + ALC injury group, 68.4% ± 3.2% in the isolated ACL injury group, and 66.8% ± 2.6% in the control group (patients who suffered from meniscal tear without ACL or ALC injury). Significantly greater LFCR was found in the ACL + ALC injury group than that in the isolated ACL injury group (p < 0.017). Greater LFCR was additionally confirmed in the ACL injury group as compared to the control group (p < 0.05). ROC curve analysis demonstrated that LFCR > 68.3% was predictive for an increased risk of ACL injury in the entire cohort. LFCR > 69.4% was predictive for an increased risk of ALC injury in non-contact ACL ruptured patients.

CONCLUSION

Increased LFCR was found to be associated with greater risk of ALC injury in non-contact ACL ruptured patients. Additionally, increased LFCR was further confirmed to be correlated with increased risk of ACL injury in an Asian population. The data from this study may help recognize patients undergoing ACL reconstruction that could benefit from additional extra-articular tenodesis.

LEVEL OF EVIDENCE

III.

The intercondylar fossa-A narrative review

The intercondylar fossa (“intercondylar notch,” IN) is a groove at the distal end of the femur, housing important stabilizing structures: cruciate ligaments and meniscofemoral ligaments. As the risk for injury to these structures correlates with changes to the IN, exact knowledge of its morphology, possible physiological and pathological changes and different approaches for evaluating it are important. The divergent ways of assessing the IN and the corresponding measurement methods have led to various descriptions of its possible shapes. Ridges at the medial and lateral wall are considered clinically important because they can help with orientation during arthroscopy, whereas ridges at the osteochondral border could affect the risk of ligament injury. Changes related to aging and sex differences have been documented, further emphasizing the importance of individual assessment of the knee joint. Overall, it is of the utmost importance to remember the interactions between the osseous housing and the structures within.

Higher Meniscal Slope Is a Risk Factor for Anterior Cruciate Ligament Injury in Skeletally Immature Patients

PURPOSE

To evaluate the relation between the femoral intercondylar index, tibial slope, and meniscal slope between 3 different groups of skeletally immature patients: primary anterior cruciate ligament (ACL) injury (group 1), ACL reconstruction failure (group 2), and control group, without an ACL injury history (group 3).

METHODS

This retrospective study evaluated magnetic resonance imaging scans of the knees of 605 skeletally immature patients obtained between 2015 and 2020. The inclusion criteria were as follows: patients younger than 16 years who were skeletally immature and underwent knee magnetic resonance imaging for any reason.

RESULTS

A total of 605 skeletally immature patients were included in the study. The ratio of patients with ACL injury (cases) to those without ACL injury (controls) was 1:2.5. Patients with ACL injury had significantly greater medial meniscal slope and lateral meniscal slope values than the control group without ACL injury (P < .001). There was no statistically significant difference between patients with primary ACL injury and those with ACL reconstruction failure for all measured variables.

CONCLUSIONS

The medial and lateral meniscal slope values were significantly higher in skeletally immature patients with ACL injury than in the control group of patients without ACL injury. There was no statistically significant difference in measurements of the femoral intercondylar index, lateral meniscal slope, medial meniscal slope, lateral tibial slope, or medial tibial slope between patients with primary injury and those with ACL reconstruction failure.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Stenotic Intercondylar Notch as a Risk Factor for Physeal-Sparing ACL Reconstruction Failure: A Case-Control Study

Identifying risk factors is crucial for developing strategies that minimize reinjury after anterior cruciate ligament reconstruction (ACLR). This study aims to determine whether certain features of intercondylar notch geometry are associated with failure of physeal-sparing ACLRs in skeletally immature athletes.

Prominent Resident's Ridge as a Potential Cause of Anterior Cruciate Ligament Impingement: A Case Report

Background

The resident's ridge is an arthroscopic landmark that is consistent with the anterior border of the anterior cruciate ligament (ACL) femoral attachment. The identification of the landmark allows for accurate graft placement.

Case Report

We report a case of a 30-year athletic individual with an ACL-deficient knee, who had an abnormally large resident's ridge, abutting the midsubstance of the torn ACL; the residual femoral attachment was behind the ridge. Resection and burring of this ridge were needed to expose the posterior aspect of the intercondylar notch; even after bone-patellar tendon-bone graft placement, some additional removal of bone had to be done to reduce graft impingement on this area in extension.

Conclusion

Abnormal resident's ridge may be misleading about the anatomy of the lateral femoral condyle area. Appropriate resection of abnormal bone is the key to the identification of femoral footprint and graft placement. We speculate that this bony projection may even have contributed to the ACL injury, and extra bone had to be removed to minimize subsequent impingement.

Narrow Notch Width is a Risk Factor for Anterior Cruciate Ligament Injury in the Pediatric Population: A Multicenter Study

Purpose

The purposes of this study were to evaluate the notch width index (NWI) as a risk factor for anterior cruciate ligament (ACL) rupture in the pediatric and adolescent patient population via multicenter analysis and to detect any differences in the NWI among cohorts having sustained either a unilateral or bilateral ACL rupture.

Methods

A consecutive series of patients ≤19 years old was enrolled from January 1999 through July 2010 at 2 academic pediatric orthopaedic tertiary-care hospitals. Demographic and anatomic morphology data were collected for 3 cohorts: unilateral ACL ruptures, bilateral ACL ruptures, and a control group. A single blinded reviewer determined notch width measurements via T2 coronal magnetic resonance imaging sequences in a standardized manner, using a previously described technique.

Results

Of the 68 patients included for analysis, 22 sustained unilateral ACL rupture, 23 sustained bilateral ruptures, and 23 comprised the control group. There was a statistically significant difference appreciated in direct comparison of the NWI in the bilateral rupture group and the control group, as well as between the unilateral rupture group and the control group. There was no statistically significant difference between the NWI in the unilateral versus the bilateral rupture group.

Conclusion

Given the known inconsistencies in the existing literature, our findings provide further support of a narrow NWI as a significant contributing factor to both unilateral and bilateral ACL injury risk in the pediatric and adolescent patient population.

Level of Evidence

III, retrospective cohort study.

The relationship of anterior cruciate ligament injuries with MRI based calculation of femoral notch width, notch width index, notch shape - A randomized control study

BACKGROUND

ACL injuries are infamously known for disability in young adults and require surgical reconstruction. The need of time is to predict predisposing factors and prevent ACL injuries.The incidence of ACL injuries has been associated with various factors related to the morphology of distal femur and proximal tibia.Hence, purpose of this study was to assess the relationship of morphology of distal femur by assessing Notch Width(NW), Notch Width Index (NWI), and Notch shape calculated preoperatively on MRI in association with an ACL tear.

METHODS

The following randomized control study had 60 patients enrolled with non contact injury to knee who were equally divided into 2 groups i.e. ACL injury group and control group. ACL group had patients who had MRI proven ACL tear along with clinical findings suggestive of ACL tear whereas control contained patients with intact ACL. Demographic data was collected and NW, NWI and Notch shape were determined on coronal sections of MRI sequences.

RESULTS

Positive correlation of ACL tear was seen with NW, BCW, NWI, NWP, and NWJ. Smaller Notch Width showed higher incidence of ACL tear (p = 0.019). The mean NWI in the injured and control knee is 0.31 ± 0.01 and 0.27 ± 0.01 respectively and was statistically significant(p < 0.001). A shaped Notch (60%) was commonly seen in ACL tear group and U shaped notch (73.3%) was commonly seen in control group.We found the cut off value for the prediction of ACL tear of NWI was 0.29 with a sensitivity of 90% and specificity of 86.7%.

CONCLUSION

ACL injuries in the given population have shown higher incidence with narrow femoral intercondylar notch, smaller notch width index, 'A' shaped femoral notch. If any of the above findings are present in the MRI, its important to counsel the subjects about the increased risk of ACL injuries in them and take preventive measures.

Increased femoral anteversion related to infratrochanteric femoral torsion is associated with ACL rupture

PURPOSE

To determine the association between femoral torsion and anterior cruciate ligament (ACL) rupture and determine the level of torsion using magnetic resonance imaging (MRI).

METHODS

The medical records of patients who were diagnosed with ACL injury were reviewed retrospectively. This descriptive epidemiological study included 2344 patients. MRI scans were examined and patients with femur and knee MRI scans obtained at the same time were identified (ACL-deficient group). Twenty-eight of them had femur and knee MRI scans because of an incidental benign lesion in the distal femur. Patients who were diagnosed with enchondroma were followed up by MRI evaluation of the femur and were randomly selected as controls. Supratrochanteric torsion (STT), infratrochanteric torsion (ITT), and femoral anteversion (FA) were measured by orthopedic surgeons with at least 5 years of experience.

RESULTS

Age, sex, and side properties were similar in both groups. The mean FA values were 19.4 ± 3.0 degrees and 11.9 ± 2.0 degrees in the ACL-deficient and control groups, respectively (p < 0.001). STT was similar in the ACL-deficient and control groups [mean: 38.2 ± 4.3 and 37.7 ± 3.3, respectively, (n.s.)]. ITT was increased in the ACL-deficient group compared with the control group (mean - 18.8 ± 4.3 and - 25.8 ± 3.8, respectively; p < 0.001).

CONCLUSIONS

According to our results, increased FA was associated with ACL rupture. Further, the torsional abnormality was developed from the ITT. We concluded that each ACL-deficient patient should be assessed by a clinician for torsional abnormality using physical examination.

LEVEL OF EVIDENCE

III.

Sex Differences in Anatomic Features Linked to Anterior Cruciate Ligament Injuries During Skeletal Growth and Maturation

BACKGROUND

Several anatomic features of the knee have been shown to affect joint and anterior cruciate ligament (ACL) loading and the risk of subsequent injuries. While several studies have highlighted sex differences between these anatomic features, little is known on how these differences develop during skeletal growth and maturation.

HYPOTHESES

(A) Anatomic features linked to an ACL injury will significantly change during skeletal growth and maturation. (B) The age-related changes in anatomic features linked to an ACL injury are different between male and female patients.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

After institutional review board approval, magnetic resonance imaging data from 269 unique knees (patient age 3-18 years; 51% female), free from any injuries, were used to measure femoral notch width, posterior slope of the lateral tibial plateau (lateral tibial slope), medial tibial depth, tibial spine height, and posterior lateral meniscal bone angle. Linear regression was used to test the associations between age and quantified anatomic indices. Patients were then divided into 4 age groups: preschool (3-6 years), prepubertal (7-10 years), early adolescent (11-14 years), and late adolescent (15-18 years). Also, 2-way analysis of variance with the Holm-Sidak post hoc test was used to compare morphology between male and female patients in each age group.

RESULTS

The femoral notch width, medial tibial depth, and tibial spine height significantly increased with age (P < .001). The lateral tibial slope decreased with age only in male patients (P < .001). Except for the posterior lateral meniscal bone angle, the age-related changes in anatomy were different between male and female patients (P < .05). On average, early and late adolescent female patients had smaller femoral notches, steeper lateral tibial slopes, flatter medial tibial plateaus, and shorter tibial spines compared with age-matched male patients (P < .01).

CONCLUSION

Overall, the findings supported our hypotheses, showing sex-specific changes in anatomic features linked to an ACL injury during skeletal growth and maturation. These observations help to better explain the reported age and sex differences in the prevalence of ACL injuries. The fact that most of these anatomic features undergo substantial changes during skeletal growth and maturation introduces the hypothesis that prophylactic interventions (ie, activity modification) would have the potential to reshape a maturing knee in a manner that lowers the risk of noncontact ACL injuries.

Correlation between notch width index assessed via magnetic resonance imaging and risk of anterior cruciate ligament injury: an updated meta-analysis

PURPOSE

To analyze the correlation between notch width index (NWI) and/or femoral intercondylar notch width (NW) assessed by magnetic resonance imaging (MRI) and risk of anterior cruciate ligament (ACL) injury.

METHODS

We searched the PubMed, Embase, China National Knowledge Infrastructure and Wanfang databases for literature reporting a correlation between ACL injury and NWI and/or NW. Subgroup analyses were stratified by ethnicity, sex and control source. The weighted mean difference (WMD) and 95% confidence intervals (95% CIs) were calculated for the ACL injury cases and controls using random- or fixed-effects models. Begg's test and sensitivity analyses were applied to assess publication bias and stability of the results, respectively.

RESULTS

Twenty-eight eligible studies were finally enrolled. The NW was significantly narrowerin the ACL injury cases than in the control cases (pooled WMD, - 1.88 [95% CI, - 2.43 to - 1.32]). The results were similar when stratified by ethnicity and sex. Similarly, the NWI was lower in ACL injury cases than in the controls. Asian populations presented similar results when stratified by ethnicity, among the self-control group when stratified by control source, and among men when stratified by sex. No publication bias was identified; however, the sensitivity analysis suggested unstable results in the NWI subgroup analysis.

CONCLUSIONS

The current meta-analysis evidenced that the NW assessed via MRI was significantly smaller in ACL injury cases than in the controls. The NWI was lower in ACL injury cases among men. Prevention strategies for ACL injury could be applied for people with intercondylar notch stenosis.

Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury: A Systematic Review

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction incidence has increased substantially in the past 25 years. Recently, there has been a focus on knee morphology as a contributor to ACL injury risk. The purpose of this study was to systematically review the literature to assess the influence of knee morphology on ACL injury.

METHODS

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, PubMed, Embase, and MEDLINE were searched in September 2017 for studies reporting on knee morphology and ACL injury. The search was updated in June 2018. The following inclusion criteria were used: English language; full text available; Level-I, II, or III evidence; human studies; and skeletally mature patients.

RESULTS

After systematically screening 6,208 studies, 65 studies met the inclusion/exclusion criteria. Three additional studies were identified in the search update, for a total of 68 studies comprising 5,834 ACL-injured knees. Intercondylar notch stenosis, most commonly defined by an "A-shaped" notch, decreased notch width, or decreased notch width index, was the most commonly reported femoral morphological risk factor for ACL injury. Increased femoral condylar offset ratio (>63%) and decreased condylar radius of curvature also were associated with an increased risk of ACL injury. Increased medial and lateral tibial slopes were the most commonly reported tibial risk factors. A smaller tibial eminence, reduced ACL size, and poor tibiofemoral congruity were also associated with increased injury risk.

CONCLUSIONS

Intercondylar notch stenosis, variations in sagittal condylar shape, increased tibial slope, reduced tibial eminence size, poor tibiofemoral congruity, and reduced ACL size are substantial risk factors for ACL injury. In future research, it would be valuable to identify a slope beyond which slope correction should be performed concomitantly with ACL reconstruction, and to determine whether an optimal relationship of notch size to graft size exists. To achieve optimal outcomes, the osseous morphological risk factors should be considered in individualized anatomic ACL reconstructions.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Intercondylar Notch Size Can Be Predicted on Preoperative Magnetic Resonance Imaging

Purpose

To develop a standardized method of intercondylar notch measurement on preoperative radiographs and magnetic resonance imaging (MRI) and validate that it could predict intraoperative notch measurements.

Methods

The charts and imaging of 50 patients undergoing anterior cruciate ligament reconstruction were reviewed. A standardized method of intercondylar notch measurement on radiographs and MRI was used by 3 blinded reviewers. Arthroscopic measurements were made by the surgeon who was blinded to the imaging measurements. Interrater reliability was determined between reviewers and between imaging and arthroscopic measurements using interclass correlation coefficients (r).

Results

The average notch base width was 16.5 (± 2.7) mm on MRI, 19.0 (± 3.4) mm on radiographs, and 15.8 (± 3.0) mm on arthroscopic measurement. The radiographic notch base width measurements were on average 1.2 times greater than the arthroscopic measurements. There was no significant difference between males and females in notch base width (16.7 mm vs 15.3 mm, P = .19) or area (312.5 mm² vs 284.3 mm², P = .17). Interrater reliability was excellent between the reviewers for notch base width measurement on both MRI (r = 0.91) and radiographs (r = 0.95). Good-to-excellent interrater reliability between notch base width measurements on MRI and arthroscopy (r = 0.78, 0.73, 0.7) and fair-to-good interrater reliability between notch base width measurements on radiographs and arthroscopy were found (r = 0.61, 0.58, 0.55).

Conclusions

This study introduces a reliable method of using preoperative MRI to predict intercondylar notch width during arthroscopy. This data can be used to identify patients with narrow notches preoperatively.

Level of Evidence

Level III, diagnostic study.

Posterior cruciate ligament injury is influenced by intercondylar shape and size of tibial eminence

AIMS

Little is known about the risk factors that predispose to a rupture of the posterior cruciate ligament (PCL). Identifying risk factors is the first step in trying to prevent a rupture of the PCL from occurring. The morphology of the knee in patients who rupture their PCL may differ from that of control patients. The purpose of this study was to identify any variations in bone morphology that are related to a PCL.

PATIENTS AND METHODS

We compared the anteroposterior (AP), lateral, and Rosenberg view radiographs of 94 patients with a ruptured PCL to a control group of 168 patients matched by age, sex, and body mass index (BMI), but with an intact PCL after a knee injury. Statistical shape modelling software was used to assess the shape of the knee and determine any difference in anatomical landmarks.

RESULTS

We found shape variants on the AP and Rosenberg view radiographs to be significantly different between patients who tore their PCL and those with an intact PCL after a knee injury. Overall, patients who ruptured their PCL have smaller intercondylar notches and smaller tibial eminences than control patients.

CONCLUSION

This study shows that differences in the shape of the knee are associated with the presence of a PCL rupture after injury. A smaller and more sharply angled intercondylar notch and a more flattened tibial eminence are related to PCL rupture. This suggests that the morphology of the knee is a risk factor for sustaining a PCL rupture. Cite this article: Bone Joint J 2019;101-B:1058-1062.

Anatomical Variability of Intercondylar Fossa Geometry in Patients Diagnosed with Primary Anterior Cruciate Ligament Rupture

The aims of this study were to (1) describe the three-dimensional characteristics and sources of anatomical variability in the geometry of the intercondylar fossa ("notch") in an anterior cruciate ligament (ACL)-injured sample and (2) assess the relationship between patient factors and anatomical variability of the fossa in the context of impingement risk. A retrospective analysis of preoperative magnetic resonance imaging (MRI) for 49 patients with ACL rupture was performed. Scans were examined in the axial plane using an online picture archiving and communication system (PACS) viewer and fossa width and angle assessed at multiple slices, as well as anteroposterior depth, fossa height, and calculated total volume. Principal component analysis was performed to prioritize the sources of variability. A multivariate linear regression was performed to assess relationships between different patient factors, controlling for imaging parameters and principal component loadings. Geometric properties were normally distributed for all but fossa volume, height, and distal angle. Three principal components (PCs) were identified explaining 80% of total variance, shape (PC1), size in the coronal plane (PC2), and size in the sagittal plane (PC3). Patient factors were significantly (P < 0.05) related to PC loadings; however, a substantial amount of variance in each model remained unexplained. Intercondylar fossa characteristics vary considerably within ACL-injury patients with shape and size in coronal and axial planes, explaining most of the variance. Although patient factors are associated with anatomical characteristics, further work is required to identify the correct combination of factors accurately predicting geometry of the fossa for planning ACL reconstruction. Clin. Anat. 33:610-618, 2020. © 2019 Wiley Periodicals, Inc.

The Combined Effect of Body Mass Index and Tibial Slope Angles on Anterior Cruciate Ligament Injury Risk in Male Knees: A Case-Control Study

Introduction:

Tibial slope angles (TSAs) have been identified as potential risk factors of anterior cruciate ligament (ACL) injury in the literature. A higher body mass index (BMI) might increase the risk of ACL tear because of greater axial compressive force. The aim of this study was to determine the relationship of these factors and the combined effect of BMI and TSA in determination of risk potential for ACL injury.

Methods:

The preoperative magnetic resonance (MR) images of 81 ACL-injured male knees and of 68 male individuals with no ACL injuries were evaluated by 2 radiologists to measure the TSA. The Mann-Whitney U-test was performed to indicate the significant difference in height, weight, and BMI values. The independent samples t-test was used to determine the differences between ACL-injured and non-injured groups regarding TSA values. Odds ratios were calculated by logistic regression tests, and receiver operating characteristics (ROC) curves revealed the area under the receiver operating characteristics curve (AUC) values to compare the relationships of these parameters with ACL injury.

Results:

Body mass index, lateral tibial slope (LTS), and medial tibial slope (MTS) were predictive of ACL risk injury. Body mass index alone had the greatest effect among these parameters, and there were no statistically significant differences in coronal tibial slope values between the ACL-ruptured and control groups. The greatest AUC was observed for the combination of BMI, MTS, and LTS.

Conclusions:

Body mass index, LTS, and MTS angles were associated with ACL injury risk and BMI + MTS + LTS together revealed the greatest effect on ACL injury.

"What's my risk of sustaining an ACL injury while playing sports?" A systematic review with meta-analysis

OBJECTIVE

To estimate the incidence proportion (IP) and incidence rate (IR) for ACL injury in athletes.

DESIGN

Systematic review with meta-analysis DATA SOURCES: The PubMed, CINAHL and SPORTDiscus electronic databases were searched from inception to 20 January 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they reported total number of participants/population by sex, total number of ACL injuries by sex and total person-time by sex.

RESULTS

Fifty-eight studies were included. The IP and IR of ACL injury in female athletes were 3.5% (1 out of every 29 athletes) and 1.5/10 000 athlete-exposures over a period of 1 season-25 years. The IP and IR of ACL injury in male athletes were 2.0% (1 out of every 50 athletes) and 0.9/10 000 athlete-exposures over a period of 1-25 years. Female athletes had a higher relative risk (RR) for ACL injury compared with males (RR=1.5; 95% CI 1.2 to 1.9; P<0.01) and a higher incidence rate ratio (IRR) of ACL injury compared with males over 1 season-25 years (IRR=1.7; 95% CI 1.4 to 2.2; P<0.010). When accounting for participation level, the disparity in the IR between female and male athletes was highest for amateur athletes compared with intermediate and elite athletes (IRR=2.1; 95% CI 1.3 to 3.4; P<0.01; I²=82%). Amateur female athletes remained at higher risk of ACL injury than did with amateur male athletes. In studies where follow-up length was <1 year, female athletes had a higher IR of ACL injury than did to males (IRR=1.7; 95% CI 1.3 to 2.2; P<0.01). Where follow-up was 1 year and beyond, there was no sex difference in the IR of ACL injury (IRR=2.1; 95% CI 0.9 to 4.8; P=0.06; I²=65%).

SUMMARY/CONCLUSIONS

One in 29 female athletes and 1 in 50 male athletes ruptured their ACL in a window that spanned from 1season to 25 years. The IR of ACL injury among female athletes in a season was 1.7 times higher than the IR of ACL injury among male athletes and the IP of ACL injury among female athletes was 1.5 times higher than the IP of ACL injury among male athletes. The reported sex disparity in ACL injury rates is independent of participation level and length of follow-up.

Anatomic risk factor for meniscal lesion in association with ACL rupture

Background

To assess anatomic risk factors for meniscal lesions in association with acute ACL rupture. The primary hypothesis was that tibiofemoral anatomic measures will be different in those with and without concomitant meniscus tears.

Methods

A retrospective review of patients who underwent acute ACL reconstruction in the department was performed. All patients underwent a postoperative CT scan. The concavity and/or convexity on the femur and the tibia were measured by two blinded observers on the sagittal plane with different ratios, and these measures were compared in patients with and without meniscus tears in each compartment. Intra- and inter-rater reliabilities were assessed.

Results

Four hundred twelve patients (268 males and 144 females) were included from October 2012 to February 2015. One hundred sixty-seven patients had a medial meniscal tear (119 males/48 females), and 100 had a lateral meniscal tear (80 males/20 females). The mean time from injury to surgery was 3 months. The average ICC for all measurements was 0.87 (range 0.82–0.98) indicating good reliability. The medial femoral condyle was noted to be significantly longer than the medial tibial plateau in the sagittal plane in patients with a medial meniscal tear (p = 0.04), and the lateral femoral condyle was noted to be significantly longer than the lateral tibial plateau in the sagittal plane in patients with a lateral meniscal tear (p <  0.001). In addition, a less convex lateral tibial plateau was statistically correlated with a higher risk of lateral meniscal tear (p = 0.001).

Conclusions

A greater anteroposterior length of the medial/lateral femoral condyle relative to the medial/lateral tibial plateau is associated with an increased risk of meniscal lesions in association with acute ACL rupture. The lateral compartment in the male population appears to be the most at risk.

Trial registration

Retrospectively registered on May 12, 2016 (CPP sud-est II CAL n°2016-037)

Lateral Posterior Tibial Slope in Male and Female Athletes Sustaining Contact Versus Noncontact Anterior Cruciate Ligament Tears: A Prospective Study

BACKGROUND

Lateral posterior tibial slope (PTS) has been identified as a risk factor for primary anterior cruciate ligament (ACL) tears.

PURPOSE/HYPOTHESIS

The purpose was to prospectively determine if there was a difference in lateral PTS between male and female athletes sustaining contact ACL tears as compared with a group of sex-, age-, and activity-matched athletes who sustained noncontact ACL tears. It was hypothesized that there would be no difference in degree of lateral PTS between contact and noncontact mechanisms among patients sustaining primary ACL tears in sports.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Data from patients who underwent primary ACL reconstruction without posterior cruciate ligament injury between 2016 and 2018 by a single surgeon were prospectively analyzed. Measurements of lateral PTS were performed on magnetic resonance imaging. Mean values of lateral PTS were compared between the ACL tear groups. Additionally, a group of patients with intact knee ligaments were matched to patients with ACL tears to serve as controls.

RESULTS

A total of 245 patients had complete primary ACL tears during the inclusion period. Of these, 56 (23%) reported a contact mechanism of injury at the time of ACL tear, and 56 patients who sustained noncontact ACL tears were matched to the contact ACL tear group. There were no significant differences in sex (P≥ .999), age (P = .990), or body mass index (P = .450) between the patient groups. The mean lateral PTS was 9.1°± 2.9° for the ACL contact and 9.9°± 3.0° for the ACL noncontact group (P = .180). There was a significant difference in mean lateral PTS between the ACL tear groups (noncontact and contact: 9.5°± 3.0°) and matched control group (5.6°± 1.9°, P = .0001).

CONCLUSION

The lateral PTS was significantly increased among patients with contact and noncontact ACL tears as compared with controls. However, there were no differences in lateral PTS between patients who sustained contact and noncontact ACL tears. Lateral PTS measured on magnetic resonance imaging does not appear to be predictive of the mechanism of injury type among patients who sustain a contact or noncontact primary ACL tear.

Anterior cruciate ligament injury risk factors in football

INTRODUCTION

Anterior cruciate ligament (ACL) lesion represents one of the most dramatic injuries in a football (soccer) player's career. There are many injury risk factors related to intrinsic (non-modifiable) and/or extrinsic (modifiable) factors of ACL injury.

EVIDENCE ACQUISITION

Research of the studies was conducted until September 2018 without publication data limitation or language restriction on the following databases: PubMed/MEDLINE, Scopus, ISI, EXCERPTA.

EVIDENCE SYNTHESIS

To date, evidence from the literature suggests that the risk of ACL injury is multifactorial and involves biomechanical, anatomical, hormonal, and neuromuscular factors. Despite this relative complexity, the mechanisms of injury are well known and rationally classified into two categories: mechanisms of injury based on contact or on non-contact with another player, with the non-contact injury mechanisms clearly prevailing over the mechanisms of contact injury. One of the most frequent biomechanical risk factors, associated with ACL non-contact injury, is represented by the valgus knee in the pivoting and cutting movements and in the landing phase after jumping. Gender-related risk factors show female populations to have a higher predisposition to ACL injury than males However, there are still some theoretical and practical aspects that need further investigation such as; genetic risks together with the role of estrogen and progesterone receptors in female populations, and the in-vivo interaction shoe-playing surface. In particular, the genetic risk factors of ACL lesion seem to be an interesting and promising field of investigation, where considerable progress has still to be made.

CONCLUSIONS

This narrative review provides an insight into the risk factors of ACL injury that could be used by practitioners for preventing injury in football (soccer).

Comparison of anatomical risk factors for noncontact anterior cruciate ligament injury using magnetic resonance imaging

PURPOSE

To compare the significance of the tibio-femoral geometrical indices (notch width index, medial and lateral tibial slopes) and patellar tendon- tibial shaft angle in predicting non-contact ACL injuries and to compare these factors between genders.

METHODS

Retrospective case control study evaluating 66 MRI knee of patients of age group of 18-60 years with 33 cases of noncontact ACL injury and 33 age matched controls. Notch width index, medial and lateral tibial slopes and patellar tendon tibial shaft angles were calculated and compared for statistical significance and was also compared between the genders. ROC curve was for plotted for the significant factors.

RESULTS

Statistically significant difference was seen in notch width index and patellar tendon tibial shaft angles with cases showing a narrow notch width index and an increased patellar tendon tibial shaft angle. Gender comparative results showed no statistically significant differences. ROC curve plotted for NWI showed an optimal cut off value of 0.263 with a sensitivity of 88% and a specificity of 52%. ROC curve plotted for PTTS angle showed a cut off value of 26.7 degrees with a sensitivity of 67% and a specificity of 49%.

CONCLUSION

Narrow Notch width index and increased Patellar tendon tibial shaft angle are predictors of ACL injury. PTTS angle which has been studied as a function of knee flexion angle, can itself be an independent predictor of ACL injury (at a constant knee flexion angle).