Molt Mats, Toksvig-Larsen Sören
a Department of Orthopedics , Hässleholm Hospital, Hässleholm and Department of Clinical Sciences, Lund University, Sweden.
Acta Orthop. 2015;86(5):594-8. doi: 10.3109/17453674.2015.1033303.
A shortened tibial stem could influence the early prosthetic fixation. We therefore compared the short stem to the standard-length stem using radiostereometric analysis (RSA) as primary outcome measure.
60 patients were randomized to receive a cemented Triathlon total knee arthroplasty (TKA) with a tibial tray of either standard or short stem length. The patients were blinded regarding treatment allocation. The micromotion of the tibial component was measured by RSA postoperatively, at 3 months, and after 1 and 2 years; clinical outcome was measured with the American Knee Society score (AKSS) and the knee osteoarthritis and injury outcome score (KOOS).
The maximum total point motion (MTPM) for the standard stem was 0.36 (SD 0.16) mm at 3 months, 0.51 (SD 0.27) mm at 1 year, and 0.54 (SD 0.28) mm at 2 years. For the short stem, it was 0.42 (0.24) mm, 0.59 (0.43) mm, and 0.61 (0.39) mm. 4 short-stemmed components and 2 standard-stemmed components had more than 0.2 mm of migration between the first- and second-year follow-up, and were classified as continuously migrating.
The short-stemmed cemented tibial prosthesis showed an early prosthetic migratory pattern similar to that of the standard-stemmed cemented Triathlon knee prosthesis. The number of continuously migrating tibial plates in each group is predictive of a lower revision rate than 5% at 10 years.
缩短的胫骨柄可能会影响假体的早期固定。因此，我们使用放射立体测量分析（RSA）作为主要结局指标，将短柄与标准长度柄进行比较。
60例患者被随机分配接受骨水泥型Triathlon全膝关节置换术（TKA），胫骨托长度为标准或短柄。患者对治疗分配不知情。术后、3个月、1年和2年后通过RSA测量胫骨组件的微动；临床结局采用美国膝关节协会评分（AKSS）和膝关节骨关节炎与损伤结局评分（KOOS）进行评估。
标准柄在3个月时的最大总点运动（MTPM）为0.36（标准差0.16）mm，1年时为0.51（标准差0.27）mm，2年时为0.54（标准差0.28）mm。短柄的相应数值分别为0.42（0.24）mm、0.59（0.43）mm和0.61（0.39）mm。4个短柄组件和2个标准柄组件在第一年和第二年随访之间的移位超过0.2mm，被归类为持续移位。
骨水泥固定的短柄胫骨假体显示出与骨水泥固定的标准柄Triathlon膝关节假体相似的早期假体移位模式。每组中持续移位的胫骨板数量预示着10年时翻修率低于5%。
