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

Abstract

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 ¼ 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.

Magnetic Resonance Imaging-Based Morphometric Analyses of the Bicruciate Injury of the Knee: Is There a Clue in the Distal Femur?

“…Also, there have been radiological as well as anthropometric studies on the Indian population that have noted similar findings [ 8 , 14 ]. Fahim et al noted a notch width of 19.9 mm ± 1.7 mm in the case group and 21.1 mm ± 1.9 mm in the control group; a NWI of 0.27 ± 0.01 in the case group; and 0.31 ± 0.01 in the control group [ 8 ]. Similarly, Park et al noted that the mean value of notch width measured 17.37 mm in the ACL-injured patients, and 20.33 mm in the control population, with an NWI of 0.23 ± 0.01 in the case group and 0.24 ± 0.01 in the control group [ 7 ].…”

Bone Morphological Characteristics as Risk Factors for Anterior Cruciate Ligament Injury: Comparison Between Contact and Noncontact Injury

“…11 As anatomical factors, the intercondylar notch width and PTS have been extensively investigated as risk factors for noncontact ACL injuries. 5,9,19,21,25,27 Type A intercondylar notch, which is narrow from the base to the midsection as well as at the apex, was associated with a significantly increased probability of suffering a noncontact ACL injury in female (OR, 4.99) and male (OR, 5.50) patients. 1 An increased alpha angle between the long axis of the distal femur and the Blumensaat line was the most significant factor associated with an ACL injury.…”

Risk Factors of ACL Injury

“…S.M. Fahim et all in their randomised control study used MRI for the calculation for NWI, reported that there were no differences in NWI in either sex and the NWI was significantly lower in those with ACL injury [28]. Ashwini et al, in their MRI based comparative study, demonstrated that people with ACL injury had NWI of 0.29 ± 0.02 or lesser compared to those without an ACL injury, whereas Bhasukala et al, postulated the cutoff of NWI to be 0.28 ± 0.06.21.…”