Figure 1
(a) Sagittal and (b) coronal T2- and sagittal T1-weighted images. (c) The ACL is dark on all pulse sequences (arrows).
Figure 2
(a) Sagittal and (b) coronal T2-weighted MRI. High signal in a thickened ACL, but no discontinuity in the fibres, consistent with partial rupture. (c) Different patient, high signal in the ACL with lot of fluid around it, but intact fibres anteriorly (arrows).
Figure 3
Sagittal and coronal T2-weighted MRI High signal in the ACL, but with discontinuity in the fibres in the posterior part, but still intact anteriorly, consistent with a partial rupture.
Figure 4
Sagittal T2-weighted MRI, typical impression in the lateral femur after a twisting injury. There is also anterior translation of the tibia compared to the femur beyond 7mm (blue dots). Total disruption of the ACL fibres in this patient.
Figure 5
(a) Sagittal T2-weighted MRI, complete disruption of the ACL fibres. (b) Avulsion of the tibial attachment of the ACL (arrows). (c) Same patient on CT.
Figure 6
(a) Intraligamentous areas of increased signal on T2- and (b) T1-weighted MRI (arrows), which indicates mucoid degeneration. Ganglion cyst (a, open arrow). (c) Mucoid degeneration may later evolve into cysts as seen on sagittal T2-weithted MRI.
Figure 7
Measurements of the centres of the femoral tunnel and tibial tunnel on CT volume-rendering reconstruction. The Bernard and Hertel grid measures the femoral placement in the deep-shallow direction. The short distance is divided by the depth of the condyle. The high-low direction is the short distance divided on the height of the condyle. The tibial tunnel is the distance from the anterior border of the tibia on the entire dept of the tibia.
Figure 8
(a) Optimal placement of tibial tunnel, posterior to the Blumensaats line on a lateral radiograph. (b, c) On a different patient, part of the tibial tunnel impingement is too anterior, and the graft has a slight “s” form on sagittal T1- and T2-weighted MRI.
Figure 9
(a) Initially, the fixation device was barely resting on the cortex on the front radiograph. (b) One year later the patient returned with reduced knee function. CT showed that the device had slid into the tunnel.
Figure 10
a–b Development of focal arthrofibrosis, soft tissue lesion with intermediate signal anterior to the graft on coronal and sagittal T2-weighted MRI (arrows).
Figure 11
(a) Sagittal T1-weighted and (b) T2-weighted MRI showed a thickened graft with high signal at 9 months after operation. (c) After two years the graft is dark and resembles the native ACL.
Figure 12
Partial rupture (verified by arthroscopy) in the anterior part of the graft (arrows), on sagittal and coronal T2-weighted MRI.
Figure 13
Total rupture of the graft, no visible fibres on sagittal T2-weighted MRI (arrow).
Figure 14
Changes in the Hoffa fat pad after surgery on sagittal T1-weighted MRI.
Figure 15
Coronal CT. Patient who had ACL construction five years ago, tunnel widening is seen in the tibia (slightly saccular expansion of the tunnel, arrows).
Figure 16
Normal signal in the PCL on sagittal T2-weighted MRI.
Figure 17
Stress radiographs of the knees, show pathological translation on the right side. It was measured to 11m whereas the normal (physiologic) translation on the left side was 5mm.
Figure 18
(a) Complete disruption of the PCL fibres. (b, c) Avulsion of the PCL attachment on the tibia on T2- and T1-weighted MRI (arrows). (d) Thick PCL >7mm, consistent with a ruptured PCL.
Figure 19
(a) The PCL has high signal in the proximal part, but the peripheral fibres seem intact (arrows), this would be called partial rupture in the ACL, but there is pathological anterior translation of the medial tibia (> 7mm) on (b), indicating PCL deficiency.
Figure 20
Post-operative tunnel placement after PCL reconstruction on volume rendering CT. Opening of the femoral tunnel is indicated with a black arrow, opening of the tibial tunnel lies between the two white arrows.
Figure 21
High signal in the PCL graft six months postoperatively on a sagittal and coronal T2, which is normal (long arrows). Short arrow shows normal ACL signal.