The LESS did not predict ACL injury in our cohort of high school and college athletes.

An athlete's risk of having a first-time noncontact ACL injury is independently influenced by level of competition, the participant's sex, and type of sport, and there are no interactions between their effects. Female college athletes have the highest risk of having a first-time noncontact ACL injury among the groups studied.

Morphometric features of both the ACL and femoral notch combine to influence the risk of suffering a noncontact ACL injury. When included together in a multivariate model that adjusts for body weight, the effects of the morphometric measurements are similar in male and female patients. If body weight is not taken into consideration, ACL volume is not associated with a risk in female patients.

There is a 21.7% increased risk of noncontact ACL injury with each degree increase of the lateral tibial plateau slope among females but not among males. The medial tibial plateau slope, coronal tibial slope, and depth of the medial tibial plateau were not associated with risk of injury for females or males.

Multivariate models provided more information about ACL injury risk than individual risk factors. Both male and female risk models included increased anterior-posterior knee laxity as a predictor of ACL injury but were otherwise dissimilar.

Context:Injuries to the anterior cruciate ligament (ACL) of the knee are immediately debilitating and can cause long-term consequences, including the early onset of osteoarthritis. It is important to have a comprehensive understanding of all possible risk factors for ACL injury to identify individuals who are at risk for future injuries and to provide an appropriate level of counseling and programs for prevention.Objective:This review, part 1 of a 2-part series, highlights what is known and still unknown regarding anatomic and neuromuscular risk factors for injury to the ACL from the current peer-reviewed literature.Data Sources:Studies were identified from MEDLINE (1951–March 2011) using the MeSH terms anterior cruciate ligament, knee injury, and risk factors. The bibliographies of relevant articles and reviews were cross-referenced to complete the search.Study Selection:Prognostic studies that utilized the case-control and prospective cohort study designs to evaluate risk factors for ACL injury were included in this review.Results:A total of 50 case-control and prospective cohort articles were included in the review, and 30 of these studies focused on neuromuscular and anatomic risk factors.Conclusions:Several anatomic and neuromuscular risk factors are associated with increased risk of suffering ACL injury—such as female sex and specific measures of bony geometry of the knee joint, including decreased intercondylar femoral notch size, decreased depth of concavity of the medial tibial plateau, increased slope of the tibial plateaus, and increased anterior-posterior knee laxity. These risk factors most likely act in combination to influence the risk of ACL injury; however, multivariate risk models that consider all the aforementioned risk factors in combination have not been established to explore this interaction.

The purpose of this study was to determine if geometry of the articular surfaces of the tibial plateau is associated with non-contact anterior cruciate ligament (ACL) injury. This was a longitudinal cohort study with a nested case-control analysis. Seventyeight subjects who suffered a non-contact ACL tear and a corresponding number of controls matched by age, sex, and sport underwent 3 T MRI of both knees. Surface geometry of the tibial articular cartilage was characterized with polynomial equations and comparisons were made between knees on the same person and between ACL-injured and control subjects. There was no difference in surface geometry between the knees of the control subjects. In contrast, there were significant differences in the surface geometry between the injured and normal knees of the ACL-injured subjects, suggesting that the ACL injury changed the cartilage surface profile. Therefore, comparisons were made between the uninjured knees of the ACL-injured subjects and the corresponding knees of their matched controls and this revealed significant differences in the surface geometry for the medial (p < 0.006) and lateral (p < 0.001) compartments. ACL-injured subjects tended to demonstrate a posterior-inferior directed orientation of the articular surface relative to the long axis of the tibia, while the control subjects were more likely to show a posterior-superior directed orientation. Severe knee injury, such as an anterior cruciate ligament (ACL) disruption, is often immediately disabling and has been associated with the early onset of post-traumatic osteoarthritis regardless of whether surgical or non-surgical treatment is chosen.1,2 This has motivated studies that have focused on identifying the variables associated with increased risk of ACL injury, so that prevention strategies can be developed and those at increased risk can be identified and targeted for intervention. 3During the process of suffering an ACL injury, the geometry of the articular surfaces of the knee is important in controlling the biomechanical response of the tibiofemoral joint and ACL. 4,5 For example, there appears to be a consensus forming in the literature that individuals who are at increased risk of suffering non-contact ACL disruptions have increased posteriorinferior directed slopes of the subchondral bone portion of their tibial plateaus compared to uninjured controls. [6][7][8][9][10][11][12][13][14][15][16] This relationship is important because the magnitude of ACL strain values produced by impulsive loading of the knee during common sportsrelated movements such as jump landings are directly related to the posterior-inferior directed slope of the subchondral bone of the proximal tibia. 4,17,18 Most of what is known about the relationship between the risk of suffering non-contact ACL injury and joint geometry has come from studies of the underlying subchondral bone of the tibia plateau; however, the large inter-segmental forces that are transmitted between the femur and tibia occur across the surface o...

The pKAM was not associated with noncontact ACL injury in our group of injured athletes and matched controls.