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Transtibial Tunnel Placement in Posterior Cruciate Ligament Reconstruction: How It Relates to the Anatomic Footprint.

Tompkins M, Keller TC, Milewski MD, Gaskin CM, Brockmeier SF, Hart JM, Miller MD - Orthop J Sports Med (2014)

Bottom Line: Generally, the tunnel is distal to the footprint.Consideration should be given to the fact that, using this transtibial technique, the tibial tunnel aperture is generally not placed in the center of the footprint.This may not be a negative issue, however, since there are other potential advantages from distal tunnel placement.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery/TRIA Orthopaedic Center, University of Minnesota, Minneapolis, Minnesota, USA.

ABSTRACT

Background: It is common to place the posterior cruciate ligament (PCL) tibial tunnel with a transtibial technique using a guide that attempts to place the center of the tunnel 1 to 1.5 cm distal to the tibiofemoral joint. It is unknown how well this technique will re-create the native tibial footprint of the PCL.

Purpose: To evaluate the accuracy of tibial tunnel placement using a transtibial technique.

Study design: Controlled laboratory study.

Methods: Ten cadaveric knees from 10 donors underwent arthroscopic transtibial drilling of the tibial tunnel with use of a posteromedial portal for visualization. The transtibial guide was rested flush against the tibial spines to allow for the guide to be as distal as possible, which was between 1 and 1.5 cm distal to the tibiofemoral joint line. Using this technique, an attempt was made to place the tibial tunnels as close to the center of the PCL footprint as possible. All knees underwent computed tomography both pre- and postoperatively with a previously reported technique optimized for ligament evaluation. This allowed comparison of the anatomic PCL tibial footprint to the tibial tunnel aperture. The percentage of tunnel aperture contained within the native footprint as well as the distance from the center of the tunnel aperture to the center of the footprint was measured.

Results: The percentage of tunnel aperture contained within the native footprint was 45.9% ± 23.1%. The distance from the center of the tibial tunnel aperture to the center of the tibial PCL footprint was 6.4 ± 2.3 mm. The tunnels were almost always (9/10) distal (or inferior) to the native footprint and either slightly lateral (5/10) or centered (5/10) in a medial to lateral direction.

Conclusion: This study demonstrates that using the transtibial drilling technique in the tibia for PCL reconstruction places approximately half of the tibial tunnel aperture within the tibial footprint. Generally, the tunnel is distal to the footprint.

Clinical relevance: Consideration should be given to the fact that, using this transtibial technique, the tibial tunnel aperture is generally not placed in the center of the footprint. This may not be a negative issue, however, since there are other potential advantages from distal tunnel placement.

No MeSH data available.


Related in: MedlinePlus

Sagittal computed tomography (CT) image demonstrating the technique for marking the tibial attachment of the posterior cruciate ligament (PCL) in a study cadaver. The high-dose 80-keV soft tissue scan algorithm allows for confident and accurate identification of the PCL footprint. The PCL (white arrows) is seen discretely. The black line represents the marking placed on each sagittal CT image where PCL fibers attach to the tibia. The black arrows represent the anterior and posterior extent of the PCL footprint.
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fig1-2325967114523384: Sagittal computed tomography (CT) image demonstrating the technique for marking the tibial attachment of the posterior cruciate ligament (PCL) in a study cadaver. The high-dose 80-keV soft tissue scan algorithm allows for confident and accurate identification of the PCL footprint. The PCL (white arrows) is seen discretely. The black line represents the marking placed on each sagittal CT image where PCL fibers attach to the tibia. The black arrows represent the anterior and posterior extent of the PCL footprint.

Mentions: Prior to any intervention, all knees underwent dual energy computed tomography (CT) scanning in a dual energy scanner (Siemens SOMATOM Definition; Siemens, Erlangen, Germany) using a technique optimized for ligament evaluation in a cadaver. After each knee had undergone transtibial tunnel drilling, they were rescanned. Commercially available third-party software (iNtuition; TeraRecon, Foster City, California, USA) was then used for image processing. The software is approved by the Food and Drug Administration and the tools are considered precise and accurate as they are based on universal DICOM (Digital Imaging and Communications in Medicine) clinical image standards. The software has been used for similar applications in previous orthopaedic publications.23,24 On the preintervention scans, sagittal reformats created from the 80-keV soft tissue algorithm axial data set were used to identify the PCL footprint (Figure 1). A line running from the anterior to the posterior extent of the PCL tibial attachment on the PCL facet was marked on each 0.625-mm sagittal slice through consensus of an orthopaedic surgeon and a musculoskeletal radiologist, while cross-referencing the axial and coronal images for guidance when needed. Applying the multiplanar reformatting tool, we created images oriented in an oblique axial plane parallel to the bony surface at the PCL tibial attachment, thus placing as many sagittal markings in one image as possible. The software was then used to fuse the marked preintervention with the postintervention CT scans, and the native tibial PCL footprint and the tibial tunnel aperture were both labeled circumferentially. This allowed anatomic comparison of the PCL footprint to the drill tunnel aperture (Figure 2). It should be noted that these are not conventional CT scan parameters, and the radiation dose would not be acceptable in live persons.


Transtibial Tunnel Placement in Posterior Cruciate Ligament Reconstruction: How It Relates to the Anatomic Footprint.

Tompkins M, Keller TC, Milewski MD, Gaskin CM, Brockmeier SF, Hart JM, Miller MD - Orthop J Sports Med (2014)

Sagittal computed tomography (CT) image demonstrating the technique for marking the tibial attachment of the posterior cruciate ligament (PCL) in a study cadaver. The high-dose 80-keV soft tissue scan algorithm allows for confident and accurate identification of the PCL footprint. The PCL (white arrows) is seen discretely. The black line represents the marking placed on each sagittal CT image where PCL fibers attach to the tibia. The black arrows represent the anterior and posterior extent of the PCL footprint.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4555621&req=5

fig1-2325967114523384: Sagittal computed tomography (CT) image demonstrating the technique for marking the tibial attachment of the posterior cruciate ligament (PCL) in a study cadaver. The high-dose 80-keV soft tissue scan algorithm allows for confident and accurate identification of the PCL footprint. The PCL (white arrows) is seen discretely. The black line represents the marking placed on each sagittal CT image where PCL fibers attach to the tibia. The black arrows represent the anterior and posterior extent of the PCL footprint.
Mentions: Prior to any intervention, all knees underwent dual energy computed tomography (CT) scanning in a dual energy scanner (Siemens SOMATOM Definition; Siemens, Erlangen, Germany) using a technique optimized for ligament evaluation in a cadaver. After each knee had undergone transtibial tunnel drilling, they were rescanned. Commercially available third-party software (iNtuition; TeraRecon, Foster City, California, USA) was then used for image processing. The software is approved by the Food and Drug Administration and the tools are considered precise and accurate as they are based on universal DICOM (Digital Imaging and Communications in Medicine) clinical image standards. The software has been used for similar applications in previous orthopaedic publications.23,24 On the preintervention scans, sagittal reformats created from the 80-keV soft tissue algorithm axial data set were used to identify the PCL footprint (Figure 1). A line running from the anterior to the posterior extent of the PCL tibial attachment on the PCL facet was marked on each 0.625-mm sagittal slice through consensus of an orthopaedic surgeon and a musculoskeletal radiologist, while cross-referencing the axial and coronal images for guidance when needed. Applying the multiplanar reformatting tool, we created images oriented in an oblique axial plane parallel to the bony surface at the PCL tibial attachment, thus placing as many sagittal markings in one image as possible. The software was then used to fuse the marked preintervention with the postintervention CT scans, and the native tibial PCL footprint and the tibial tunnel aperture were both labeled circumferentially. This allowed anatomic comparison of the PCL footprint to the drill tunnel aperture (Figure 2). It should be noted that these are not conventional CT scan parameters, and the radiation dose would not be acceptable in live persons.

Bottom Line: Generally, the tunnel is distal to the footprint.Consideration should be given to the fact that, using this transtibial technique, the tibial tunnel aperture is generally not placed in the center of the footprint.This may not be a negative issue, however, since there are other potential advantages from distal tunnel placement.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery/TRIA Orthopaedic Center, University of Minnesota, Minneapolis, Minnesota, USA.

ABSTRACT

Background: It is common to place the posterior cruciate ligament (PCL) tibial tunnel with a transtibial technique using a guide that attempts to place the center of the tunnel 1 to 1.5 cm distal to the tibiofemoral joint. It is unknown how well this technique will re-create the native tibial footprint of the PCL.

Purpose: To evaluate the accuracy of tibial tunnel placement using a transtibial technique.

Study design: Controlled laboratory study.

Methods: Ten cadaveric knees from 10 donors underwent arthroscopic transtibial drilling of the tibial tunnel with use of a posteromedial portal for visualization. The transtibial guide was rested flush against the tibial spines to allow for the guide to be as distal as possible, which was between 1 and 1.5 cm distal to the tibiofemoral joint line. Using this technique, an attempt was made to place the tibial tunnels as close to the center of the PCL footprint as possible. All knees underwent computed tomography both pre- and postoperatively with a previously reported technique optimized for ligament evaluation. This allowed comparison of the anatomic PCL tibial footprint to the tibial tunnel aperture. The percentage of tunnel aperture contained within the native footprint as well as the distance from the center of the tunnel aperture to the center of the footprint was measured.

Results: The percentage of tunnel aperture contained within the native footprint was 45.9% ± 23.1%. The distance from the center of the tibial tunnel aperture to the center of the tibial PCL footprint was 6.4 ± 2.3 mm. The tunnels were almost always (9/10) distal (or inferior) to the native footprint and either slightly lateral (5/10) or centered (5/10) in a medial to lateral direction.

Conclusion: This study demonstrates that using the transtibial drilling technique in the tibia for PCL reconstruction places approximately half of the tibial tunnel aperture within the tibial footprint. Generally, the tunnel is distal to the footprint.

Clinical relevance: Consideration should be given to the fact that, using this transtibial technique, the tibial tunnel aperture is generally not placed in the center of the footprint. This may not be a negative issue, however, since there are other potential advantages from distal tunnel placement.

No MeSH data available.


Related in: MedlinePlus