Chouteau J, Lerat J L, Testa R, Moyen B, Fessy M H, Banks S A
Service de chirurgie orthopédique, de traumatologie et de médecine du sport, Centre Hospitalier Lyon-Sud, Chemin du Grand Revoyet, 69495 Pierre Bénite, Cedex, France.
Knee. 2009 Jun;16(3):223-7. doi: 10.1016/j.knee.2008.11.008. Epub 2008 Dec 13.
Mobile bearing (MB) total knee arthroplasty (TKA) was developed to provide low contact stress and unconstrained joint motion. We studied a consecutive series of 41 knees with mobile-bearing, posterior cruciate-retaining (CR) TKAs to determine if kinematics resembled normal knees or if kinematics changed over time. Patients were studied at 3 and 21 months average follow-up with weight-bearing radiographs at full extension, 30 degrees flexion and maximum flexion. Shape-matching techniques were used to measure TKA kinematics. Implant hyperextension, maximum flexion and total ROM increased with follow-up. Tibial rotation and condylar translations did not change with time. The medial condyle did not translate from extension to 30 degrees, but translated 5 mm anteriorly from 30 degrees to maximum flexion. Lateral condylar translation was 3 mm posterior from extension to 30 degrees, with no translation from 30 degrees to maximum flexion. Tibiofemoral kinematics in CR-MB-TKAs were stable over time, but did not replicate motions observed in healthy knees. The mobile tibial insert showed rotation and translation at both follow-up examinations, but the patterns of translation were not predictable.
活动轴承（MB）全膝关节置换术（TKA）的研发旨在提供低接触应力和无约束的关节活动。我们研究了连续的41例采用活动轴承、保留后交叉韧带（CR）的TKA病例，以确定其运动学是否类似于正常膝关节，或者运动学是否随时间变化。在平均随访3个月和21个月时，对患者进行负重X线片检查，拍摄完全伸直、30度屈曲和最大屈曲位的片子。采用形状匹配技术测量TKA的运动学。随着随访时间的延长，假体的过伸、最大屈曲度和总活动度均增加。胫骨旋转和髁间移位不随时间变化。内侧髁从伸直位到30度屈曲位无移位，但从30度屈曲位到最大屈曲位向前移位5毫米。外侧髁从伸直位到30度屈曲位向后移位3毫米，从30度屈曲位到最大屈曲位无移位。CR-MB-TKA的胫股关节运动学随时间稳定，但无法复制在健康膝关节中观察到的运动。在两次随访检查中，活动胫骨衬垫均显示有旋转和移位，但移位模式不可预测。
