A case-control study of anterior cruciate ligament volume, tibial plateau slopes and intercondylar notch dimensions in ACL-injured knees

Abstract

The role played by anatomic factors in ACL injury remains elusive. In this study, objective methods were used to characterize ACL volume, tibial slopes, and notch geometry from ACL-injured and matched control subjects. The study tested four hypotheses: 1) the medial tibial plateau slope is steeper posteriorly in the injured group compared to the non-injured group, 2) the lateral tibial plateau slope is steeper posteriorly in the injured group compared to the non-injured group, 3) the femoral intercondylar notch dimensions are smaller in the injured group compared to the non-injured group and 4) the ACL volume, tibial plateau slopes and intercondylar notch dimensions are all independent of each other. Fifty-four subjects were divided into two groups, those who had suffered a non-contact ACL injury and those who still had two healthy ACLs, matched to the injured subjects by gender, age, height and weight. The lateral tibial plateaus in the uninjured contralateral knees of the injured subjects had a significantly steeper posterior slope (1.8° vs. −0.3°), a factor that potentially contributed to the ACL injury in the opposite knee. The intercondylar notch dimensions were found to be smaller in the injured subjects, potentially putting the ACL at risk of impingement, and intercondylar notch volume was correlated to ACL volume (r=0.58). Discriminant analysis showed that the notch width at the inlet was the best single predictor of ACL injury.

Anatomical Risk Factors for Rupture of the Anterior Cruciate Ligament: Magnetic Resonance Imaging Based Knee Joint Assessment

“…Our study was a case-control study. Similar studies designs have been carried out in the past by Simon et al [4], Wordeman et al [5] in the United States of America; Freychet et al [6] in France, among many others. One of the most important sources of bias in a study of this type arises from the selection of the different subjects to constitute the case and control groups.…”

“…• Tibial slopes: These were measured using the new combined method proposed by Khan et al [4], which had the smallest inter and intra-observer variabilities. From sagittal slices on the medial tibial sagittal section, we determined the axis of the tibia.…”

Risk factors for anterior cruciate ligament injury: assessment of tibial plateau anatomic variables on conventional MRI using a new combined method

“…Several risk factors have been proposed, both internal (anatomical, hormonal, neuromuscular, and familial) and external (type of sports, footwear, and environment) [2][3][4]. Among anatomical risk factors, most studies have been conducted on the size of intercondylar notch [5][6][7][8], but recently, posterior tibial slope (PTS) has also been identified as an important risk factor [9][10][11][12][13][14][15][16][17][18][19]. Tibial plateau slopes, medial plateau (MTPS) and lateral plateau (LTPS), independently are important determinants of knee biomechanics.…”

ACL Research Retreat V: An Update on ACL Injury Risk and Prevention, March 25–27, 2010, Greensboro, NC

“…have smaller ACLs (area and volume), 42 greater posterior slope of the lateral tibia, 43,44 similar slope of the medial tibia, 43,44 reduced condylar depth on the medial tibial plateau, 43 and presence of an anterior medial ridge on the intercondylar notch. 45 6.…”