Reconstructed anterior cruciate ligaments using patellar tendon ligament grafts: diagnostic value of contrast-enhanced MRI in a 2-year follow-up regimen.

We analyzed prospectively the diagnostic efficacy of contrast-enhanced MRI following anterior cruciate neoligament (ACL) reconstruction. One hundred fifty-six MR examinations were performed 2, 12, 52, 76, and 104 weeks post-operatively on 68 patients with ACL transplants. Sagittal, parasagittal, and coronal images using unenhanced T1- and T2-weighted spinecho sequences, and post-contrast images utilizing T1-weighted spinecho and fat-saturated sequences, were acquired. Results were correlated with those of the pivot shift, Lachman, and a mechanical test. The MR examination criteria included morphological analysis, signal intensity, transplant contrast enhancement, secondary signs (e.g., elongation of normal ligaments), and comparison with clinically standardized test results. Two weeks post-operatively all neoligaments showed homogeneous low signal intensity on T1- and T2-weighted spinecho sequences indistinguishable from that of normal cruciate or patellar ligaments [contrast-to-noise ratio (C/N) on T1: 1.6], with a 9% percentile enhancement. At 12-52 weeks, signal intensity increased (C/N: 6.7), with a mean 50% percentile enhancement. The 1-year follow-up allowed no definite assessment of the neoligament's course. At 76 and 104 weeks, significant decrements in signal intensity (C/N: 3.0) and ligamentous percentile enhancement (25%) occurred. All patients tested displayed stable transplants 2 years post-operatively. Contrast-enhanced MRI allows accurate evaluation of morphology and function up to 3 months postoperatively and 1-2 years following ACL reconstructive surgery.

Anterior cruciate ligament reconstruction: the diagnostic value of MRI.

A prospective study was carried out in order to evaluate the predictive value of MRI in the early postoperative course after cruciate ligament replacement. Twenty patients who had undergone anterior cruciate ligament reconstruction using autologous patellar tendon/bone grafts were examined clinically and with contrast enhanced MRI at 2, 12 and 24 weeks, and 1 and 2 years after operation. The clinical findings were evaluated according to the scores established by Lysholm, OAK and IKDC. The MRI scans (SP 63, 1.5 Tesla) were assessed in terms of the quality and signal intensity of the reconstructed ligaments. During the first postoperative year there was a significant increase of signal intensity and in homogeneity of the neoligament on in the MRI. Seventeen patients had an average value for signal/noise of 1.1 at two weeks after surgery, which had increased to 7.1 at 1 year. In 14 patients the reconstructed ligament could not be evaluated in MRI scans after 1 year but clinical instability was not suspected in any of these patients. Two years after operation the MRI signal, intensity of the neoligament was again decreasing.

Magnetic resonance imaging in the diagnosis of acute injured distal tibiofibular syndesmosis.

RATIONALE AND OBJECTIVES: This study assessed the diagnostic potential of magnetic resonance imaging for the evaluation of the tibiofibular syndesmosis. METHODS: A total of 38 patients with an acute ankle trauma and clinical suspicion of a syndesmotic tear were prospectively studied with conventional plain film radiography and magnetic resonance imaging. Magnetic resonance imaging studies included plain T1-weighted (T1-w) and T2-weighted (T2-w) sequences and contrast-enhanced T1-w sequences 0 to 3 days after trauma. All images were read by two independent radiologists before surgical intervention. Sensitivity and specificity were determined for the two observers and the concordance of the two observers were calculated using the interobserver analysis (Kappa-Test). Intraoperative inspection (n = 21) revealed rupture of the anterior tibiofibular ligament (ATIF) in 15 patients, intact ATIF in 6 patients, and intact posterior tibiofibular ligament (PTIF) in 21 cases. Clinical and follow-up examinations revealed an intact syndesmotic complex in another 17 patients. RESULTS: Primary diagnostic criteria for diagnosing a ligamentous tear included tibiofibular diastasis in conventional plain films; nonvisualization of the ATIF; an abnormal course, a wavy, irregular contour of the ligament; increased signal intensity of the ligament in T2-w sequences, in plain T1-w sequence, and marked enhancement in T1-w after contrast. Important secondary signs were defined as joint fluid in the tibiofibular space and prolapse of interspace fat. Highest diagnostic accuracy was achieved if three or more diagnostic criteria could be visualized. Both readers performed best with the enhanced T1-weighted and the T2-weighted images in transverse orientation. The interobserver analysis resulted in high concordance: Kappa = 0.9 (confidence interval: 0.76 to 1.00) for all patients, and in Kappa = 0.76 (confidence interval: 0.45 to 1.0) for surgically treated patients. CONCLUSIONS: Magnetic resonance imaging of the syndesmotic complex is a highly sensitive and specific tool for the pretherapeutic-evaluation of syndesmotic injury.

[Value of MRI in assessment of cruciate ligament replacement]. / Wertigkeit der MRT in der Beurteilung des Kreuzbandersatzes.

To evaluate the predictive value of MRI in the early postoperative course after cruciate ligament replacement, a prospective study was performed. Twenty patients with reconstructed anterior and/or posterior cruciate ligament were examined clinically and with contrast-enhanced MRI 2, 12, 24 weeks, 1 and 2 years postoperatively. The clinical examinations were evaluated according to the scores by Lysholm, OAK and IKDC. The MRI scans (SP 63, 1.5 Tesla) were evaluated regarding the quality and signal intensity of the reconstructed ligament. During the first postoperative year a significant increase in signal intensity and inhomogeneity of the neoligament in MRI was observed in 16 patients with an average value for signal/noise of 1.1 2 weeks postoperatively up to 6.9 1 year postoperatively. In 12 patients the reconstructed ligament could not be evaluated in the 1-year postoperative MRI, whereas none of these patients was suspected clinically of having instability. In the 2-year postoperative MRI, the signal intensity of the neoligament was found to be decreasing again with improvement in judgement.