3D computer tomography for measurement of femoral position in acl reconstruction

Yoo

et al. 2018

Knee Surg Relat Res

PurposeLittle is known about the isometry of anatomic single-bundle anterior cruciate ligament (ACL) tunnel positions in vivo although it is closely related to graft tension throughout the range of motion. The purpose of this study was to evaluate intraoperative graft isometry in anatomic single-bundle ACL reconstruction in vivo.Materials and MethodsGraft length changes were assessed before bio-screw fixation in the tibial tunnel by pulling the graft with tensions of 20 lbs and 30 lbs in full extension at flexion angles of 30°, 60°, 90°, and 120°.ResultsAt the flexion angle of 30°, 20 lbs and 30 lbs of tension showed −0.4 mm and −0.6 mm length changes, respectively. The greater the flexion angle of the knee, the shorter the graft length in the joint. At the flexion angles of 90° and 120°, there was significant difference in the graft length change between 20 lbs and 30 lbs of tension.ConclusionsAnatomic single-bundle ACL reconstruction was non-isometric. The graft length was the longest in full extension. The tension of graft became loose in flexion. At the flexion angles of 90° and 120°, there was significant difference in the graft length change between 20 lbs and 30 lbs of tension.

Section: Methodsmentioning

confidence: 99%

Intraoperative Graft Isometry in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Yoo

et al. 2018

Knee Surg Relat Res

“…The transparent 3D CT protocol has already been proven to accurately measure the ACL femoral tunnel, 16 and uses an open-source software that requires a lower level of technical skill. However, this tool is chosen less frequently when compared to the conventional 3D CT image-rendering protocol.…”

Section: Discussionmentioning

confidence: 99%

“…Images were acquired including intercondylar notch and lateral condyle in a bone transparent imaging technique similar to radiographies (transparency 3D MPR protocol) available in this software. 16 As mentioned before, posterior femoral condyle walls were aligned in sagittal and axial view and inferior walls in sagittal and coronal views to standardize the lateral view. Central point of the ACL tunnel position was set using sagittal, coronal and axial planes.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Comparison Between Rendering 3d-Ct and Transparent 3d-Ct in Acl Tunnel Positioning

et al. 2017

Self Cite

Objective: To compare the transparent 3D computed tomography (CT) image protocol against conventional 3D-CT image-rendering protocol to assess femoral tunnel position in anatomic anterior cruciate ligament (ACL) reconstructions . Methods: Eight knee CT scans from cadavers were analyzed by image rendering 3D-CT protocol, using Rhinoceros(r) software. The central point of the ACL tunnel was set using the sagittal plane. Same CT scans were analyzed using transparent 3D-CT measurement protocol with OsiriX(r) software. Central point of the ACL tunnel was set using sagittal, coronal and axial planes. The grid system described by Bernard and Hertel was used to compare tunnel positions between protocols, using height and length parameters . Results: There was a significant difference between measurements using image rendering 3D-CT and transparent 3D-CT protocol for height (23.8 ± 7.9mm and 33.0 ± 5.0mm, respectively; p=0.017) and no differences for length (18.6 ± 4.2mm and 18.3 ± 4.5mm, respectively; p=0.560) . Conclusion: Height in transparent CT protocol was different and length was the same as compared to 3D-CT rendering protocol in Bernard and Hertel method for tunnel measurements. Level of Evidence II, Descriptive Laboratory Study.

“…In the absence of standardized methods to obtain the images for assessment of femoral tunnel position both in the horizontal and vertical planes 12) , the quadrant method applicable to 3D CT models has been referred to as one of the best ways to evaluate the femoral tunnel position and thus it has been widely used in previous studies 10) . Using this method, Bird et al 9) reported the coordinates of the optimal anatomic femoral tunnel position, which was based on the mean coordinates previously described by six authors.…”

Section: Discussionmentioning

confidence: 99%

Tomographic Study of Femoral Positioning in Anterior Cruciate Ligament Reconstruction Using the Transtibial Technique

Silva

Matos

Costa

et al. 2017

Knee Surg Relat Res

PurposeTo analyze the location of the femoral tunnel by three-dimensional computed tomography (3D CT) of the lateral condyle in patients who underwent arthroscopic single-bundle anterior cruciate ligament (ACL) reconstruction, performed using a modified transtibial technique, and to compare the results with data from the literature.Materials and MethodsSeventeen patients with ACL lesions underwent modified transtibial ACL reconstruction. Postoperatively, 3D CT examinations were performed and the images were analyzed by the quadrant system described by Bernard and Hertel to define the femoral tunnel coordinates.ResultsThe mean value of femoral tunnel location coordinates was 37.1±5.9 in the horizontal plane and 23.9±7.5 in the vertical plane. Compared with other studies using the transtibial or transportal technique, femoral positioning was improved in the vertical plane. The outside-in technique provided the best results both in the vertical and horizontal planes.ConclusionsThe modified transtibial technique was not effective for systematically anatomic femoral tunnel positioning; however, it was relatively better than the conventional transtibial technique.