Center for Hip and Knee Surgery, St. Francis Hospital, Mooresville, Mooresville, Indiana, USA.
J Arthroplasty. 2011 Jun;26(4):591-5. doi: 10.1016/j.arth.2010.05.008.
The influence of intramedullary (IM) and extramedullary (EM) femoral cutting guides on survivorship of total knee arthroplasty was studied in 6726 total knee arthroplasty guided by either an IM (4993 knees) or EM (1733 knees) system. Fifteen-year survivorship of the 2 cohorts showed no statistically significant difference (EM 97.9% vs IM 98.5%; P = .2500, log rank). Medial bone collapse comprised the highest proportion of all failure modes for both groups (0.35% vs 0.40%, respectively, P = .6731, Cox regression). Mean tibiofemoral (overall) anatomical alignment was statistically more accurate in the IM group (IM 4.6° [± 2.2°] valgus vs EM 5.1° [± 3.1°] valgus; P < .0001). The mean tibial alignment was 90.5° (± 3.0) and 90.3° (± 2.2) (P = .0077). The EM group had a significantly larger tibial component alignment variance (SD(2)) than the IM group. No statistical difference in postoperative Knee Society scores, pain, or stair-climbing abilities was found. The choice of either alignment system should be determined by the patient's anatomy; however, the overall alignment is not as precise using the extramedullary system.
髓内（IM）和髓外（EM）股骨切割导向器对全膝关节置换术的存活率的影响，在 6726 例全膝关节置换术中进行了研究，这些患者分别接受了 IM（4993 例）或 EM（1733 例）系统的引导。两组 15 年的存活率无统计学显著差异（EM 为 97.9%，IM 为 98.5%；P =.2500，对数秩检验）。对于两组患者，所有失败模式中，内侧骨塌陷占比最高（分别为 0.35%和 0.40%，P =.6731，Cox 回归）。IM 组的胫股（整体）解剖对线平均更准确（IM 为 4.6°[±2.2°]外翻，EM 为 5.1°[±3.1°]外翻；P <.0001）。平均胫骨对线为 90.5°（±3.0）和 90.3°（±2.2）（P =.0077）。EM 组的胫骨组件对线方差（SD(2)）明显大于 IM 组。术后膝关节协会评分、疼痛或爬楼梯能力无统计学差异。两种对线系统的选择应根据患者的解剖结构而定；然而，使用髓外系统的总体对线并不那么精确。
