Intra-and interobserver reliability of determining the femoral footprint of the torn anterior cruciate ligament on MRI scans

Abstract

Background Re-injury rates following reconstruction of the anterior cruciate ligament (ACL) are significant; in more than 20% of patients a rupture of the graft occurs. One of the main reasons for graft failure is malposition of the femoral tunnel. The femoral origin of the torn ACL can be hard to visualize during arthroscopy, plus many individual variation in femoral origin anatomy exists, which may lead to this malpositioning. To develop a patient specific guide that may resolve this problem, a preoperative MRI is needed to identify the patient specific femoral origin of the ACL. The issue here is that there may be a difference in the reliability of identification of the femoral footprint of the ACL on MRI between different observers with different backgrounds and level of experience. The purpose of this study was to determine the intra- and interobserver reliability of identifying the femoral footprint of the torn ACL on MRI and to compare this between orthopedic surgeons, residents in orthopedic surgery and MSK radiologists. Methods MR images of the knee joint were collected retrospectively from 20 subjects with a confirmed rupture of the ACL. The 2D (coronal, sagittal, transversal) proton-density (PD) images were selected for the segmentation procedure to create 3D models of the femurs. The center of the femoral footprint of the ACL on 20 MRI scans, with visual feedback on 3D models (as reference) was determined twice by eight observers. The intra- and interobserver reliability of determining the center of the femoral footprint on MRI was evaluated. Intraclass correlation coefficients (ICCs) were calculated for the X, Y and Z coordinates separately and for a 3D coordinate. Results The mean 3D distance between the first and second assessment (intraobserver reliability) was 3.82 mm. The mean 3D distance between observers (interobserver reliability) was 8.67 mm. ICCs were excellent (> 0.95), except for those between the assessments of the two MSK radiologists of the Y and Z coordinates (0.890 and 0.800 respectively). Orthopedic surgeons outscored the residents and radiologists in terms of intra- and interobserver agreement. Conclusion Excellent intraobserver reliability was demonstrated (< 4 mm). However the results of the interobserver reliability manifested remarkably less agreement between observers (> 8 mm). An orthopedic background seems to increase both intra- and interobserver reliability. Preoperative planning of the femoral tunnel position in ACL reconstruction remains a surgical decision. Experienced orthopedic surgeons should be consulted when planning for patient specific instrumentation in ACL reconstruction.

Distribution of bone tunnel positions and treatment efficacy of bone landmark positioning method for anatomical reconstruction of the anterior cruciate ligament: a case control study

“…Finally, 22 patients were in the good position group, 62 patients were in the poor position group, and the rate of good bone tunnel position was only 26.2%. Moloney et al showed that if only depending on bone landmarks, the femoral positioning site might be deviated by > 2.5 mm from the original footprint center by more than half of surgeons, indicating that the positioning by intra-articular bone landmarks was not reliable [ 9 , 15 , 21 ]. The findings were in agreement with the results of the present study, which showed that the positions of femoral tunnels were not concentrated, and the rate of good bone tunnel position was low.…”

“…Of these factors, bone tunnel is an important influencing factor. During the surgical procedures of ACL reconstruction, various femoral tunnel positioning methods have already been discovered [ 2 – 9 ]. However, none of the methods are suitable for all the conditions, and no single method can be recommended to treat all types of diseases; instead, suitable methods should be selected according to the lateral femoral wall.…”

Patient specific instrumentation in ACL reconstruction: a proof-of-concept cadaver experiment assessing drilling accuracy when using 3D printed guides

“…Using the Mimics Innovation Suite Software version 21.0 (Materialise, Leuven, Belgium), the images were segmented to obtain accurate 3D models of the knee. The MRI images were semi-automatically segmented with the use of the livewire technique as previously described [ 29 ]. Using this technique, the software is able to semi-automatically distinguish different gray scales in order to select a region of interest.…”

“…Previous research has shown that the identification of the femoral insertion using this method has a high intra- and interobserver reliability, even in the presence of ACL injury [ 29 ]. Intra-observer reliability for this method has been shown to be excellent with an ICC of > 0.98 and excellent interobserver reliability with an ICC of > 0.96.…”

The Effect on Absence of Clinical History and Demographic Data in Diagnostic Accuracy of Genitourinary Cytopathological Cases Among Undergraduate Medical Laboratory Technology (MLT) Students

“…This constraint will affect the inter-and intra-observer reliability in genitourinary case diagnosis. The kappa value was used to conduct reliability tests, which included inter-observer (agreement between two observers & agreement between separate observers) and intra-observer (agreement between one observer experiences when observing the same case or more than once) (2,3,15). It might be difficult for the observer to make an accurate diagnosis in the absence of clinical history, thus reduce the reliability of slide observers to report cases (4,16).…”