Imaging of knee injuries with special focus on tibial plateau fractures

Acute knee injury is a common event throughout life, and it is usually the result of a traffic accident, simple fall, or twisting injury. Over 90% of patients with acute knee injury undergo radiography. An overlooked fracture or delayed diagnosis can lead to poor patient outcome. The major aim of this thesis was retrospectively to study imaging of knee injury with a special focus on tibial plateau fractures in patients referred to a level-one trauma center. Multi-detector computed tomography (MDCT) findings of acute knee trauma were studied and compared to radiography, as well as whether non-contrast MDCT can detect cruciate ligaments with reasonable accuracy. The prevalence, type, and location of meniscal injuries in magnetic resonance imaging (MRI) were evaluated, particularly in order to assess the prevalence of unstable meniscal tears in acute knee trauma with tibial plateau fractures. The possibility to analyze with conventional MRI the signal appearance of menisci repaired with bioabsorbable arrows was also studied. The postoperative use of MDCT was studied in surgically treated tibial plateau fractures: to establish the frequency and indications of MDCT and to assess the common findings and their clinical impact in a level-one trauma hospital. This thesis focused on MDCT and MRI of knee injuries, and radiographs were analyzed when applica-ble. Radiography constitutes the basis for imaging acute knee injury, but MDCT can yield information beyond the capabilities of radiography. Especially in severely injured patients , sufficient radiographs are often difficult to obtain, and in those patients, radiography is unreliable to rule out fractures. MDCT detected intact cruciate ligaments with good specificity, accuracy, and negative predictive value, but the assessment of torn ligaments was unreliable. A total of 36% (14/39) patients with tibial plateau fracture had an unstable meniscal tear in MRI. When a meniscal tear is properly detected preoperatively, treatment can be combined with primary fracture fixation, thus avoiding another operation. The number of meniscal contusions was high. Awareness of the imaging features of this meniscal abnormality can help radiologists increase specificity by avoiding false-positive findings in meniscal tears. Postoperative menisci treated with bioabsorbable arrows showed no difference, among different signal intensities in MRI, among menisci between patients with operated or intact ACL. The highest incidence of menisci with an increased signal intensity extending to the meniscal surface was in patients whose surgery was within the previous 18 months. The results may indicate that a rather long time is necessary for menisci to heal completely after arrow repair. Whether the menisci with an increased signal intensity extending to the meniscal surface represent improper healing or re-tear, or whether this is just the earlier healing feature in the natural process remains unclear, and further prospective studies are needed to clarify this. Postoperative use of MDCT in tibial plateau fractures was rather infrequent even in this large trauma center, but when performed, it revealed clinically significant information, thus benefitting patients in regard to treatment.

Carotid Surgery : A posse ad esse non valet consequentia

According to a large body of evidence, carotid endarterectomy (CEA) can prevent strokes, provided that appropriate inclusion criteria and high-quality perioperative treatment methods are utilised with low complication rates. From the patient s perspective, it is of paramount importance that the operation is as safe and effective as possible. From the community s point of view, it is important that CEA provision prevents as many strokes as possible. In order to define the stroke preventing potential of CEA in different communities, a comparison between eight European countries and Australia was performed including 53 077 carotid interventions. A more detailed evaluation was performed in Finland, the United Kingdom and Egypt. It could be estimated that many potentially preventable strokes occur due to insufficient diagnostics and CEA provision. The number of CEAs should be at least doubled in the Helsinki region. The theoretical power of CEA provision in stroke prevention varied significantly between the countries. Delay from symptom to surgery has been identified as one of the most important factors influencing the effectiveness of CEA. In 2008 only 11% of CEAs in Helsinki university central hospital (HUCH) were performed within the recommended14 days. Registered data of 673 CEAs in HUCH during 2000-2005 was analyzed. There was no systematic error that would have changed the outcome analysis. However it is important that registers are audited regularly and cross matching of different registries is possible. A previously unpublished method of combining medial mandibulotomy, neck incision and carotid artery interposition was carried out as a collaboration of maxillofacial, ear, nose and throat and vascular surgeons. Five patients were operated on with a technique that was feasible and possible to perform with little morbidity, but due to the significant risks involved, this technique should be reserved for carefully selected cases. In stroke prevention, organisational decisions seem far more important than details in interventional procedures when CEA is performed with low complication rates, as was the case in the present study. A TIA clinic approach with close co-operation between the on-call vascular surgeons, neurologists and radiologists should be available at all centres treating these patients. Patients should have a direct and fast admission to the hospital performing CEA.