Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury

Abstract

Update This article was updated on June 9, 2020, because of previous errors. On pages 703 and 716, in the byline section and author affiliation section, “Kevin Wilson” now reads “Kevin W. Wilson,” “K. Wilson” now reads “K.W. Wilson,” and “Kevin Wilson, MD2” now reads “Kevin W. Wilson, MD3.” The affiliation for Dr. Wilson that had read “2Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, Maryland” now reads “3Department of Orthopaedic Surgery, Mount Nittany Health, State College, Pennsylvania” with affiliations 3 through 6 renumbered as 4 through 7. An erratum has been published: J Bone Joint Surg Am. 2020 Jul 15;102(14):e85. 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.

Lateral Meniscus Height and ACL Reconstruction Failure: A Nested Case–Control Study

“…4 Moreover, variations in the sagittal condylar shape, relatively small tibial eminence size, poor tibiofemoral congruity, and reduced ACL size have also been described as potential risk factors for ACL injury. 5 In addition, inadequate postoperative discharge programs, infection, untreated meniscal tears, suboptimal surgical technique, and graft quality related problems have also been associated with ACL reconstruction failure. 2 The integrity of the menisci has been found to be another important factor to achieve optimal outcomes after a primary ACL repair.…”

Editorial Commentary: Femoral Notch Volume: Too Much Information?

“…Only about half (12 of 23) of studies analyzed in a recent systematic review reported a significant association of notch width with ACL injury risk. 1 Is 3-dimensional notch volume a better measure? Although more difficult to assess from magnetic resonance imaging (MRI) or computed tomography than simple notch width (requiring a multislice 3-dimensional analysis), it may provide a better indicator of the true "space" available for an ACL or graft (and therefore the likelihood of damaging impingement and ACL injury risk) than simpler parameters.…”

“…The past few decades of ACL injury research have certainly made us aware of several morphological joint characteristics that could contribute to ACL injury risk, including notch shape, notch width, femoral condyle offset, tibial slope, ACL size, joint congruity, and other measures. 1 As described earlier, there is considerable overlap in notch characteristics between the injured and uninjured groups, and the statistics are not really strong enough to justify using these morphological measures to suggest that individuals with small notches but no injury history should avoid playing high-risk sports (most athletes would be resistant to such advice anyway). Probably few if any surgeons would recommend prophylactic surgery to reduce injury risk, except perhaps in the case of severe deformity.…”

Risk factors for noncontact anterior cruciate ligament injury in female high school basketball and handball players: A prospective 3-year cohort study

“… 6 , 7 , 8 , 9 , 10 Numerous anatomic ACL injury risk factors have been identified, e.g., an increased lateral posterior tibial slope and narrowing of the intercondylar fossa of the femur. 11 , 12 Subtalar joint overpronation has been reported to be associated with noncontact ACL injuries. 13 It has been suggested that this may be a product of overpronation increasing anterior translation of the tibia with respect to the femur, thereby increasing the strain on the ACL.…”

“…Female athletes are three to six times more likely to sustain a sports-related noncontact ACL injury than male athletes in comparable high-risk sports. 11 , 17 , 18 The ACL injury risk has, in some studies, been reported to be higher in elite sporting contexts than in non-elite sporting contexts. 19 According to a previous report regarding the age distribution of knee injury, the mean age at injury was observed to be 17.0 ± 2.0 years.…”