Gemalmaz Halil Can, Sarıyılmaz Kerim, Ozkunt Okan, Sungur Mustafa, Kaya Ibrahim, Dikici Fatih
Acıbadem Mehmet Ali Aydınlar University, School of Medicine, Department of Orthopaedics and Traumatology, Istanbul, Turkey.
Acıbadem Mehmet Ali Aydınlar University, Faculty of Health Sciences, Istanbul, Turkey.
Acta Orthop Traumatol Turc. 2019 Sep;53(5):323-328. doi: 10.1016/j.aott.2019.02.001. Epub 2019 Mar 8.
Total knee replacement (TKR) is a surgical treatment for final stage gonarthrosis. The lifespan of the prosthetic implants used in TKR surgery is a major interest for the orthopaedic research community.Previously, proper implant alignment of the implants has been advocated for longevity of the TKR surgery. Recently, patient-specific (PSI) instruments have been proposed to improve the mechanical alignment of the TKR by permitting better implant positioning over conventional TKR surgery. The aim of this study is to compare the mechanical alignment results of patients operated with PSIs and conventional instruments.
Two groups of 20 patients chosen in a quasi-random manner have been compared in this study. In the first group femoral distal and tibial osteotomies were made by a PSI which was produced by the patients' computed tomography scans. All osteotomies in the control group were made with the TKR set's routine instruments by conventional means. Patients' preoperative and postoperative mechanical femorotibal angles (mFTA), femoral coronal angles (FCA), tibial coronal angles (TCA) were measured and the number of outliers which showed more than 3° of malalignment were counted in both groups for comparison.
The average postoperative mFTA was found to be 2.09° for the PSI group and in was found to be 2.84° for the control which was not statistically significant. The comparison of postoperative FCA and TCA also did not show significant difference between the groups. The number of outliers showing more than 3° of malalignment per group were found to be 1 out of 20 (5%) for the PSI group and 7 out of 20 (35%) for the control which was statistically significant.
In this study patient-specific instrumentation provided significantly better mechanical alignment compared to conventional TKR for the frequency of outlier cases with malalignment beyond 3°. PSI proved no significant difference when the groups were compared for mFTA, FCA and TCA. Our findings support that PSI may improve TKR alignment by improving the ratio of the outlier patients with marked malalignment.
Level III, Therapeutic Study.
全膝关节置换术（TKR）是终末期膝关节炎的一种外科治疗方法。TKR手术中使用的假体植入物的使用寿命是骨科研究界主要关注的问题。此前，一直提倡通过正确的植入物对线来延长TKR手术的使用寿命。最近，有人提出了患者特异性（PSI）器械，通过在传统TKR手术中实现更好的植入物定位来改善TKR的机械对线。本研究的目的是比较使用PSI器械和传统器械进行手术的患者的机械对线结果。
本研究以准随机方式选取了两组各20例患者进行比较。第一组通过患者的计算机断层扫描生成的PSI进行股骨远端和胫骨截骨。对照组的所有截骨均采用TKR套件的常规器械通过传统方法进行。测量患者术前和术后的机械股胫角（mFTA）、股骨冠状角（FCA）、胫骨冠状角（TCA），并统计两组中显示对线不良超过3°的异常值数量进行比较。
PSI组术后平均mFTA为2.09°，对照组为2.84°，差异无统计学意义。术后FCA和TCA的比较在两组之间也未显示出显著差异。PSI组中显示对线不良超过3°的异常值数量为20例中的1例（5%）,对照组为20例中的7例（35%），差异有统计学意义。
在本研究中，与传统TKR相比，患者特异性器械在对线不良超过3°的异常病例发生率方面提供了明显更好的机械对线。当比较两组的mFTA、FCA和TCA时，PSI没有显示出显著差异。我们的研究结果支持，PSI可能通过改善明显对线不良的异常患者比例来改善TKR对线。
三级，治疗性研究。
