ACL-injured Group Research Articles

The influence of the tibial plateau slopes on injury of the anterior cruciate ligament: a meta-analysis

The purpose of this meta-analysis was (1) to examine the effect of the tibial plateau slopes (medial and lateral) on anterior cruciate ligament (ACL) injury and (2) to investigate gender differences between ACL-injured subjects and gender-matched controls. The PubMed database was searched through to 1 November 2011 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies, the characteristics of the study participants, exposure and outcome assessments, and control for potential confounding factors. A meta-analysis was conducted, and either a fixed- or a random-effects model was used to calculate the overall weighted mean difference (WMD). Twelve studies (n = 1,871: 923 patients in the ACL-injured group and 938 patients in the control group) were included. The medial tibial plateau slope in the ACL group ranged from 1.8° ± 3.7° to 12.1° ± 3.3° while it ranged from 2.9° ± 2.8° to 9.5° ± 3° among the controls. The lateral tibial plateau slope in the ACL ranged from 1.8° ± 3.2° to 11.5° ± 3.5° and 0.3° ± 3.6° to 9° ± 4° in the control group. Statistically significant increased angles were observed in ACL-injured group compared to control group for medial tibial plateau slope (WMD, 1.1°; 95 % confidence interval, 0.5°-1.7°) and lateral tibial plateau slope (WMD, 1.8°; 95 % confidence interval, 1.3°-2.3°). Sensitivity analysis and subgroup analysis proved this to be a reliable result. The current meta-analysis suggests that both, increased medial and lateral tibial plateau slopes, are associated with increased susceptibility to ACL injury regardless of gender. In addition, this study indicates a stronger evidence for lateral tibial plateau slope to be associated with ACL injury compared with medial tibial plateau slope due to the larger increased angle value and on the basis of consistency among the included studies.

The influence of the intercondylar notch dimensions on injury of the anterior cruciate ligament: a meta-analysis

The aim of this meta-analysis was to examine the effect of the intercondylar notch dimensions, intercondylar notch width index (NWI) and intercondylar notch width (NW), separately in anterior cruciate ligament (ACL) injury. The PubMed and Wanfang database were searched through until 1 November 2011 to identify studies that met pre-stated inclusion criteria. Reference lists of retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies, the characteristics of the study participants, exposure and outcome assessments and control for potential confounding factors. Either a fixed- or a random-effects model was used to calculate the overall weighted mean difference (WMD). Sixteen studies (n = 4,291) were included (1,222 subjects in ACL-injured group and 3,069 subjects in the control group). Statistically significant differences were observed in the NWI (WMD, -0.02; 95 % confidence interval, -0.04 to -0.01), and in the NW (WMD, -2.15; 95 % confidence interval, -3.09 to -1.21) among the ACL-injured group when compared to the control group. The meta-analysis findings concluded that narrow intercondylar notch dimensions were associated with the risk of ACL injury. A lower NWI or NW stenosis predisposes an individual to ACL injury. Further original studies should include more anatomical risk factors that could be associated with the risk of ACL injury.

In Vivo Evidence for Tibial Plateau Slope as a Risk Factor for Anterior Cruciate Ligament Injury

Background: In vivo studies reporting tibial plateau slope as a risk factor for anterior cruciate ligament (ACL) injury have been published with greatly increasing frequency. Purpose: To examine and summarize the in vivo evidence comparing tibial slope in ACL-injured and uninjured populations. Study Design: Systematic review and meta-analysis. Methods: We reviewed publications in Scopus, SPORTDiscus, CINAHL, and PubMed to identify all studies reporting a measure of tibial plateau slope between ACL-injured groups and controls. A meta-analysis was performed including calculation of effect size and 95% confidence interval as well as 95% confidence intervals for the mean values of the measurement in each study. Results: Fourteen studies met our inclusion/exclusion criteria. Five of 6 radiographic studies reporting medial tibial plateau slope (MTPS) demonstrated significant differences between controls and ACL-injured groups, while only 1 of 7 magnetic resonance imaging (MRI) studies reported significant differences between groups. Mean MTPS measurements and standard deviations reported for controls ranged from 2.9° ± 2.8° anterior to 9.5° ± 3° posterior. For ACL-injured patients, MTPS ranged from 1.8° ± 3.5° anterior to 12.1° ± 3.3° posterior. Lateral tibial plateau slope (LTPS) was reported to be significantly greater in ACL-injured groups in all 5 MRI-based studies reporting group comparisons. Mean values for LTPS in controls ranged from 0.3° ± 3.6° anterior slope to 9° ± 4° posterior slope. In ACL-injured groups, mean reported LTPS values ranged from 1.8° ± 3.2° to 11.5° ± 3.54° posterior slope. Conclusion: Despite high measures of reliability for the various methods reported in current studies, there is vast disagreement regarding the actual values of the slope that would be considered “at risk.” Reported tibial slope values for control groups vary greatly between studies. In many cases, the study-to-study differences in “normal” tibial slope exceed the difference between controls and ACL-injured patients. The clinical utility of imaging-based measurement methods for the determination of ACL injury risk requires more reliable techniques that demonstrate consistency between studies.

Isolation and characterization of human meniscus-derived vascular stem cells

Isolation and characterization of human meniscus-derived vascular stem cells

Impaired healing of anterior cruciate ligament correlates with kinins expression

Purpose: ACL is the most frequently injured ligament of the knee, with over 100,000 reconstructions performed annually. Reconstruction of injured ligaments is still a problem. The discovery that cartilage can make products of the kinin-kallikrein pathway and its receptors suggests that it can not only respond to products of the pathway but initiate this inflammatory process in the joint by providing bradykinin (BK). An understanding of the process of ACL healing evolves, new markers will be indentified that will be accurate measures of this process. The purpose of the study was to define the levels of serum markers C1, 2C, C2C (cartilage degradation), CPII, CS846 (cartilage formation), natural (IgA, IgM, IgG) antibodies against BK (healing of ACL) in a cohort of patients before and after ACL reconstruction and compare them to matched, uninjured controls. Methods: Patients undergoing ACL reconstruction were matched with uninjured controls of similar age, sex, and BMI. Serum drawn upon entry to USMA and prior to graduation from both groups were tested ELISA kits (IBEX, Inc, Montreal, CA). In order to quantify NA to BK in the sera, were designed, synthesized and then used to develop a novel ELISA kits (INR). Results: Different classes of NA (IgM, IgG, IgA) against BK were detected with our ELISA protocol in the sera of ACL patients as well as in the sera of controls. There was no significant difference in binding of serum BK-IgA and BK-IgG levels in ACL patients in comparison with that in controls. Serum BK-IgM levels is elevated in patients after ACL reconstruction and correlate with individual and composite measures of the healing activity. There were significant differences (p<0.05) in the C2C and CPII levels between groups pre-injury, but not the C1, 2C and CS846 levels. There were significant differences (p<0.05) in the C1, 2C, C2C, and CPII levels between groups in the post-reconstruction state, but not for CS846. Comparing within group changes, all markers were significantly different over time (p<0.05) in both groups except for the controls C1, 2C and ACL injured CS846. Significant group by time interactions were observed (p<0.05) for C2C and CS846. Elevated BK-IgM in the sera was significantly correlated with C2C (r=0.85; p<0.0001) and CII (r=0.69; p<0.0003) in ACL patients in the post-reconstruction state. Conclusions: The process of ACL healing is highly complex, but is slowly starting to become more well defined. Kinins can stimulate the upregulation and production of cartilage after ACL reconstruction. A significant relationship was found between the examined markers of cartilage formation and degradation and the dynamic change of serum levels of kinins after ACL reconstruction. The difference in BK-IgM, CPII and C2C levels in the pre-injury state suggests that there may be differences in cartilage metabolism of individuals at risk for ACL tear. Significant changes over time were observed in kinins markers in the ACL-injured group and further study is warranted into the prognostic capabilities of these markers.

Decreased femoral head–neck offset: a possible risk factor for ACL injury

PurposeReduction in anterior cruciate ligament (ACL) injuries in young, active individuals continues to be a major goal in sports medicine. The purpose of this study was to determine the head–neck offset, as measured by AP pelvis alpha angles, in patients presenting to a single surgeon with isolated ACL and non-ACL knee injuries.MethodsIn a group of 48 patients with complete, primary ACL rupture and 42 controls with non-ACL injury (i.e., meniscus tear, cartilage defect), a single surgeon, blinded to the diagnosis, took radiographic measures of the AP alpha angle of both hips and the weight-bearing line at both knees. All knee pathology was confirmed with knee arthroscopy. Inclusion criteria included no previous hip or knee surgery, and long-leg standing alignment radiographic series completed at index visit.ResultsThere was no difference in gender distribution, height, BMI or age between groups. ACL-injured patients had a significantly higher alpha angle (mean = 84, SD = 14) on the injured side than the controls (mean = 59, SD = 7, p < 0.0001). Ninety-four percent of the ACL-injured group had alpha angles over 60°, while only 35% of the non-ACL-injured group had alpha angles over 60° (p = 0.001). Those patients with alpha angle over 60° were 27 times more likely (95% CI 6.4–131) to be in the ACL injury group than those patients with alpha angle 60° or less (p = 0.001).ConclusionOur findings establish an important preliminary correlation between ACL injury and diminished femoral head–neck offset, as characterized by abnormal, elevated alpha angles.Level of evidencePrognostic study, Level III.

Gender difference of the femoral kinematics axis location and its relation to anterior cruciate ligament injury: a 3D-CT study

The variation of distal femur morphology has been often reported, especially in relation to ACL injury. However, it remains unknown how morphological differences affect knee kinematics and ACL function. The location of the transcondylar axis, a common anatomical reference line, may be a significant aspect of morphological variation. It was hypothesized that the location of this axis would be different between genders, and between ACL-injured and non-injured subjects. 3D CT scans of contralateral healthy femurs in 38 unilateral soft tissue injured patients (20 men/18 women, 26 ACL injury/12 non-ACL injury (7 with PCL injuries and 5 with medial meniscus root tears)) were analyzed three-dimensionally. Condyle offset was calculated as the distance between the transcondylar axis and the anatomical axis of the femur. Condyle offset ratio (COR) was then calculated by dividing the condyle offset by the condyle radius. Gender and ACL-injured and non-injured group differences were assessed. Larger COR was found in women, 1.10±0.14, than men, 0.96±0.08. In women, the ACL-injured group had significantly larger COR than the non-ACL injury group, but no difference was found in men. COR is a unique morphological feature which is measureable from 3D CT. COR is larger in women, and could be a possible risk indicator for ACL injury in the female population. III.

The Association of Lateral Knee Sagittal Radius of Curvature with ACL Injury: Gender or Geometry? (SS-67)

Introduction Attributes of femoral condyle and tibial plateau geometry may play a role in the stability of the knee. We studied differences in lateral knee length and radial geometry in ACL-injured and uninjured cohorts. Methods 185 age- and activity-matched uninjured and non-contact unilateral (uACL)- and bilateral (bACL)-injured groups were included. MRI measurements of the articular cartilage surfaces in the mid-weight-bearing sagittal plane of the lateral compartment evaluated tibial plateau radius of curvature (TPr) and distal femoral radius of curvature (Fr). The Fr was measured at the weight-bearing segment of a best fit logarithmic curve (Fibonacci sequence). Measurements were also made of the maximum distance from anterior to posterior femur perpendicular to the femoral shaft (FAP) and anteroposterior tibial articular length (TPAP). Calculations of Fr:TPr and FAP:TPAP were used to adjust for individual variations in anatomic size. Measurements were made by 3 observers blinded to gender and injury group. Interclass correlation coefficient was performed to assess inter-rater reliability. Two-sampled Student t-tests were used to compare quantitive variables. All data represented a normal distribution. Results Combined gender: The mean lateral plateau radius of curvature, femoral radius of curvature, and tibial plateau lengths were all significantly smaller in ACL-injured versus non-injured groups (33.6 vs. 37.4mm, p=0.003; 25.1 vs. 24.2mm, p=0.01; 31.4 vs. 33.2mm, p=0.004; respectively). Femoral length was not different between ACL-injured and uninjured groups (p=0.19). Adjusting for size differences, FAP:TPAP was significantly larger in injured versus controls, indicating that the length of the tibial plateau was significantly smaller relative to the femur in injury groups. Gender Groups (Table 1): No significant differences existed between ACL-injured females and uninjured females with respect to femoral length, tibial length, femoral radius, tibial plateau radius or FAP:TPAP. Conversely, compared to uninjured males, ACL-injured males demonstrated significantly smaller tibial plateau radius (41.1 vs. 35.3mm), femoral radius (26.7 vs. 25.5mm), and tibial plateau length (35.5 vs. 33.1mm). No differences existed between femoral length between injured and uninjured males. FAP:TPAP differences suggested that the length of the tibial plateau was significantly shorter relative to the femur in ACL-injured males (p Conclusion Our data suggest that all females (injured or uninjured) and ACL-injured males share a common lateral knee geometry characterized by a shorter tibial plateau length relative to the femur and smaller (more convex) articulating surfaces of both the proximal tibia and distal femur. It is possible that the opposition of two highly-convex articulating surfaces may be inherently less stable to anterior tibial translation and rotation. These findings also may help to explain the apparent female predilection for ACL injury compared to males, but suggest that this may be as much driven by geometry as it is by gender.

Anterior Cruciate Ligament Injury in Female and Male Athletes

It has been shown that anterior cruciate ligament (ACL) injuries are more prevalent in female athletes than in male athletes. Soccer and basketball are considered high-risk sports for ACL injury in female athletes. Several studies have reported a relationship between ACL injury and measures of foot structure. This study was conducted to investigate the relationship between foot structure and ACL injury rates in female and male soccer and basketball players. One hundred five soccer and basketball players (53 women and 52 men) were recruited and divided into an ACL-normal group (n=89) and an ACL-injured group (n=16). Two measures of foot structure (subtalar joint neutral position and navicular drop test values) were recorded for each subject. An independent t test and a paired t test were used to analyze differences in ACL status, foot structure, and sex. A chi2 analysis determined whether the prevalence of ACL injury was independent of sport. No statistically significant differences were found in the foot structure measures between women and men. Female soccer and basketball players had an ACL injury rate seven times that of male players. Values derived from subtalar joint neutral position measurement and the navicular drop test were not associated with ACL injury in collegiate female and male soccer and basketball players.