Biomechanical investigations on chondromalacia of the knee after meniscal flap lesion and partial meniscal resection: an experimental model.
Meniscal tears and resections may cause chondral lesions of the knee. To eliminate muscular control during investigation of this problem, we designed a biomechanical setup based on a knee-joint simulator, ensuring physiological, free-motion mobility of the joint. Fresh human knee specimens with intact cartilage were exposed to loads to 2,000 N at a frequency of 0.85 Hz during 48 hours of gait. After a preliminary test series, 18 specimens were divided into three groups: group I was tested with unchanged meniscal status, group II with arthroscopically induced mobile flap tears at the posterior horns of the menisci, and group III after partial resection of the posterior horns. Motion patterns between the groups changed after as little as a few hours due to increased translation in group III. Macroscopic and histological examination and scanning electron microscopy revealed severe chondromalacic changes after meniscal resection. We conclude that meniscal resection-however partial-may have considerable joint-damaging potential if muscle control is lacking whereas mobile flap tears maintain stability. Our findings might explain the differences in clinical reports on cartilage status after partial meniscal resection. This study underlines the importance of muscle training when active stabilisation of the knee is reduced after partial meniscal resection.
Department of Orthopaedic Surgery, University of Regensburg, Bad Abbach, Germany.
J K
JK
Grifka
T
T
Kalteis
E
E
Broll-Zeitvogel
S
S
Philippou
W
W
Plitz
D000328:Adult; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D013524:Surgical Flaps