Mechanism of traumatic knee injuries and MRI findings.

Bone bruises are focal abnormalities in subchondral bone marrow due to trabecular microfractures as a result of traumatic force. These trauma-induced lesions are better detected with magnetic resonance (MR) imaging using water-sensitive sequences. Moreover, the pattern of bone bruise is distinctive and allows us to understand the dynamics of trauma and to predict associated soft injuries. This article discusses the mechanism of traumatic injury and MR findings.

Financial impact of radiological reports on medical-legal evaluation of compensation for meniscal lesions.

To evaluate any discrepancy between radiological reports for clinical purposes and for medicolegal purposes and to quantify its economic impact on repayments made by private insurance companies for meniscal injuries of the knee. The medical records obtained pertaining to 108 knee injury patients (mean age 43.3 years) assessed over a period of 12 months were analysed. Clinical medical reports, aimed at assessing the lesion, and medicolegal reports, drawn up with a view to quantifying compensation, were compared. Unlike reports for clinical purposes in reports for medicolegal purposes, in the evaluation of meniscal lesions, in addition to morphological features of lesions, chronological, topographical, severity and exclusion criteria were applied. To estimate the economic impact resulting from the biological damage, we consulted an actuarial table based on the 9-point minor incapacity classification system. Meniscal lesions not compatible with a traumatic event and therefore not eligible for an insurance payout were found in 56 patients. Of these, 37 failed exclusion criteria, while 19 failed to meet chronological criteria. This difference resulted in a reduction in compensation made by private insurance companies with savings estimated with a saving between euro 203,715.41 and euro 622,315.39. The use of a clinical report for medicolegal purposes can be a source of valuation error, as chronological and/or dynamic information regarding the trauma mechanism may be lacking. Therefore, the use of a full radiological appraisal allows a better damage's assessment and an adequate compensation for injuries.

Lesions of the rotator cuff footprint: diagnostic performance of MR arthrography compared with arthroscopy.

BACKGROUND: To evaluate the diagnostic performance of magnetic resonance arthrography (MR-A) of the shoulder in the diagnosis of rotator cuff tears involving the humeral insertion of the supraspinatus and infraspinatus tendon (footprint), using arthroscopy as the reference standard. MATERIALS AND METHODS: The study population included 90 consecutive patients with history and clinical diagnosis of instability of the shoulder, rotator cuff tear or posterosuperior glenoid impingement. A total of 108 MR arthrograms were performed, since 18 patients had undergone a bilateral procedure. Arthroscopy, which was performed within 45 days after MR-A, was used as the reference standard. Sensitivity, specificity, accuracy, positive and negative predictive values were then calculated. RESULTS: Magnetic resonance arthrography showed a sensitivity of 92 % and a specificity of 78 % for the overall detection of tears involving the rotator cuff footprint. The diagnostic accuracy was 90 %, and the positive and negative predictive values were 95 and 64 %, respectively. Ten lesions were non-classifiable on surgery, of which eight were non-classifiable on MR-A also. CONCLUSIONS: Magnetic resonance arthrography is extremely accurate for the detection and classification of rotator cuff footprint tears. Most of these lesions are articular-sided (partial articular-sided supraspinatus tendon avulsion lesions) with predominance in younger patients and concealed type of tear (concealed interstitial delamination lesions).

Rotator cable at MR imaging: considerations on morphological aspects and biomechanical role.

PURPOSE: The rotator cable (RC) is a thickening of the coracohumeral ligament. It extends from the coracohumeral ligament to the inferior border of the infraspinatus tendon, with fibres running perpendicularly to the rotator cuff fibres. According to some authors, the RC tends to thicken with age, thus allowing some individuals with a cuff lesion to preserve normal shoulder function. We evaluated the RC with magnetic resonance (MR) imaging and investigated its possible role in the biomechanics of the shoulder affected by cuff lesions. MATERIALS AND METHODS: Between November 2007 and May 2008, we performed shoulder MR examinations for shoulder pain or disability on 94 patients (46 males, 48 females; age range 16-79 years; mean age 54.09 ± 15.09 years) for a total of 104 shoulders (62 right, 42 left). RESULTS: RC was more easily detectable in oblique coronal scans where it appeared as a crescent-shaped, regularly marginated structure adjacent to the articular surface of the supraspinatus tendon and medial to the insertion point of this tendon on the greater tuberosity. Its thickness was 2.8 ± 0.3 mm. The structure was identified in 62% of cases (mean patient age 55.3 ± 14.9 years). No statistically significant difference in age was found between patients with and without evidence of RC (Student's t test=0.05; p=0.82). Among patients with partial- or full-thickness supraspinatus tendon lesions at MR imaging, no statistically significant difference was found between the presence or absence of RC and disability on Jobe's test (χ(2)=1.17; p>0.05). CONCLUSIONS: RC can be observed at MR imaging in >60% cases. In our sample it did not seem to influence shoulder function in patients with cuff lesions.