Translation der Menisken und Femurkondylen relativ zur Tibia bei Patienten mit vorderer Kreuzbandruptur - Analyse mit der offenen Magnetresonanztomographie

Bringmann, Christoph (2003): Translation der Menisken und Femurkondylen relativ zur Tibia bei Patienten mit vorderer Kreuzbandruptur - Analyse mit der offenen Magnetresonanztomographie. Dissertation, LMU München: Medizinische Fakultät

Abstract

Objective: To analyze menisco-tibial and femoro-tibial translation patterns in healthy and ACL-deficient knees in different knee flexion angles under muscle activity. Methods: The ACL-deficient and contralateral healthy knees of 10 patients were examined with an open MR system at 30° and 90° of knee flexion, under both flexing and extending, isometric muscle activity. Translations between the tibia, the femoral condyles and the menisci were analyzed by three-dimensional image postprocessing. Results: Posterior translation of the femur and menisci relative to the tibia occurred during knee flexion (30°-90°). In ACL-deficient knees, posterior translation of the medial femoral condyle (+1.3±3.8 mm) was significantly larger than in healthy knee (-0.9±2.9 mm; p<0.05) The translation pattern of the menisci, in contrast, was similar (med. meniscus 0.6±2.3 mm vs. 0.6±2.7 mm). Under extending (relative to flexing) muscle activity, an increased posterior position of the femur and menisci was observed relative to the tibia at 30° knee flexion, but not at 90°. This applied to ACL-deficient and healthy knees. Conclusions: This study shows a significant increase of translation of the medial femoral condyle in ACL-deficient knees, whereas menisco-tibial translation is unchanged. This difference in displacement indicates that the posterior horn of the medial meniscus might encounter shear, potentially explaining the high rate of secondary medial meniscal tears in patients with ACL-deficiency.

Abstract

Objective: To analyze menisco-tibial and femoro-tibial translation patterns in healthy and ACL-deficient knees in different knee flexion angles under muscle activity. Methods: The ACL-deficient and contralateral healthy knees of 10 patients were examined with an open MR system at 30° and 90° of knee flexion, under both flexing and extending, isometric muscle activity. Translations between the tibia, the femoral condyles and the menisci were analyzed by three-dimensional image postprocessing. Results: Posterior translation of the femur and menisci relative to the tibia occurred during knee flexion (30°-90°). In ACL-deficient knees, posterior translation of the medial femoral condyle (+1.3±3.8 mm) was significantly larger than in healthy knee (-0.9±2.9 mm; p<0.05) The translation pattern of the menisci, in contrast, was similar (med. meniscus 0.6±2.3 mm vs. 0.6±2.7 mm). Under extending (relative to flexing) muscle activity, an increased posterior position of the femur and menisci was observed relative to the tibia at 30° knee flexion, but not at 90°. This applied to ACL-deficient and healthy knees. Conclusions: This study shows a significant increase of translation of the medial femoral condyle in ACL-deficient knees, whereas menisco-tibial translation is unchanged. This difference in displacement indicates that the posterior horn of the medial meniscus might encounter shear, potentially explaining the high rate of secondary medial meniscal tears in patients with ACL-deficiency.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: Kniegelenk, anterior cruciate ligament, translation, meniscus, MRT
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften ; 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• Fakultäten: Medizinische Fakultät
• Sprache der Hochschulschrift: Deutsch
• Datum der mündlichen Prüfung: 27. November 2003