The effect of posterior tibial slope on range of motion after total knee arthroplasty

Posterior slope has been theorized as advantageous to range of motion (ROM) after total knee arthroplasty. This study was undertaken to assess the accuracy of a 0 degrees and a 5 degrees posterior sloped intramedullary (IM) cutting guide and the effect of the posterior tibial slope on postoperative ROM. Thirty-one consecutive patients underwent total knee arthroplasty using a cutting block and intramedullary cutting guide designed to impart a 0 degrees posterior tibial slope (group 1). A 5 degrees tibia cutting block was used in 30 subsequent patients (group 2). The posterior slope measurement represented the angle between a line drawn parallel to the articular surface and a line drawn perpendicular to the long axis of the tibia on a lateral radiograph. Mean postoperative tibial slope measured 1.8 degrees for group 1 and 5.5 degrees for group 2. There was no significant difference between groups for postoperative flexion or improvement of Hospital for Special Surgery score. The tibial cutting guides accurately achieved the intended posterior slope, but increasing posterior slope did not result in a significant increase in ROM or Hospital for Special Surgery functional score.     

Akagi胫骨前后轴在全膝关节置换术中的定位作用

目的 分析膝关节CT片上Akagi胫骨前后轴与髌腱中内1/3点、髌腱内侧缘等解剖标志的相互关系,确定全膝关节置换术中胫骨假体旋转定位的参照轴线.方法 对40名青年健康志愿者行膝关节伸直中立位CT检查.Akagi胫骨前后轴定义为CT片上垂直于外科经上髁轴且经过后十字韧带中点的直线.于胫骨平台平而及预定截骨平面标记胫骨前后轴及其与髌腱相交点、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线,分别测量胫骨前后轴与髌腱相交点内侧髌腱占髌腱总宽度的比例、后十字韧带中点与髌腱内侧缘及髌腱中内1/3点连线同胫骨前后轴之间的夹角.结果 在胫骨平台平面,胫骨前后轴经过髌腱内侧缘外侧10.1%±8.3%处;在预定截骨平面,胫骨前后轴经过髌腱内侧缘外侧0.2%±10.0%处.在预定截骨平面,后十字韧带中点与髌腱内侧缘连线和胫骨前后轴的夹角为0.1°±2.7°,后十字韧带中点与髌腱中内1/3点连线和胫骨前后轴的夹角为10.3°±3.6°.结论 全膝关节置换术中,当以胫骨结节中内1/3点为标准行胫骨假体旋转放置时,有导致胫骨假体相对于股骨假体过度外旋的可能.后十字韧带中点与髌腱内侧缘连线几乎与Akagi胫骨前后轴重叠,可以作为全膝关节置换术中胫骨假体旋转定位的参照轴线.     

Posterior tibial slope in the normal and varus knee.

Posterior tibial slope was evaluated in 30 normal and 30 varus knees using magnetic resonance imaging. The mean tibial posterior slope in the medial plateau was 10.7 degrees (range: 5 degrees - 15.5 degrees) in the normal knees and 9.9 degrees (range: 1.5 degrees - 19 degrees) in the varus knees. The mean tibial posterior slope in the lateral plateau was 7.2 degrees (range: 0 degrees - 14.5 degrees) in the normal knees and 6 degrees (range: 1 degrees - 13 degrees) in the varus knees. Although these differences were not statistically significant, there was a large range in the posterior tibial slope in both groups. When 10-mm thickness of bone was resected in the middle of the lateral plateau in total knee arthroplasty, the thickness of the bone resection in the anterior and posterior part of the lateral plateau was measured. The presumed thickness of bone was 10.1 mm (range: 7.3-13.9 mm) in the anterior part and 7.5 mm (range: 5-10.3 mm) in the posterior part. A large range in the measured thickness of bone also was detected in the varus knees. These results suggest that the shape of the proximal tibia varies among individuals and that the cutting angle should be determined in each case to avoid any mismatch of the patient's posterior slope of the tibia after implantation.     

The Anteroposterior Axis of the Proximal Tibia Can Change After Tibial Resection in Total Knee Arthroplasty: Computer Simulation Using Asian Osteoarthritis Knees

Background

We evaluated the effect of cutting surface on the anteroposterior (AP) axis of the proximal tibia using a 3-dimensional (3D) bone model to ensure proper tibial rotational alignment in total knee arthroplasty.

Importance of the lateral anatomic tibial slope as a guide to the tibial cut in total knee arthroplasty in Japanese patients

Using three-dimensional computed tomography in 50 osteoarthritic knees, we simulated at various cutting angles the tibial cut for total knee arthroplasty. Cutting angles of 0°, 3°, 5°, 7°, 9°, and 11° were used. We then calculated the anterior and posterior thicknesses, the medial-lateral widths, and the medial and lateral condylar depths of the resected tibial bone at each cutting angle. Each set of measurements was evaluated according to a comparison between the cutting angle and the anatomic posterior slopes. The cutting angles showing the smallest anterior-posterior difference at the medial and lateral plateaus were 9° and 7°, respectively. The mean anatomic posterior slopes at the medial and lateral plateaus were 9.0° and 8.1°, respectively. When the tibia was cut at the cutting angle closest to the medial anatomical posterior slope in each knee, the thickness of the lateral posterior plateaus resected from 12 knees (24%) was more than 10mm. Among these 12 knees, the cutting angle was more than 9° in 9 knees (75%). In contrast, when the tibia was cut at the cutting angle closest to the lateral anatomical posterior slope, only one resected medial posterior plateau was more than 10mm. The cutting angle of this case was 7°. Therefore, in consideration of the thickness of bone resection from anatomic posterior slope, we demonstrated the importance of using the lateral anatomic posterior tibial slope as a guide to the tibial cut. There was no significant difference with respect to resected bone morphology at any cutting angle.     

Anatomic variations should be considered in total knee arthroplasty

The effect of anatomic variations on the operative techniques used in total knee arthroplasty (TKA) was assessed. In 133 Japanese patients with medial osteoarthritis (OA), six parameters were measured on anteroposterior radiographs of the lower extremities taken with the patients in the supine position. The results showed that the characteristics of the knees were bowing of the femoral shaft and proximal tibia vara, with lateral offset of the tibial shaft with respect to the center of the tibial plateau. The angle between a perpendicular to the mechanical axis and the tangent to the distal femoral condyles can be used in determining the external rotation of the femoral component. This angle was more than 3° in 20% of the patients. The femoral component should therefore be externally rotated more than 3° relative to the posterior condylar line in such patients. Because the center of the tibial plateau is located medial to the central line of the tibial shaft in knees with medial OA, the central point of the tibial articular surface should not be used for alignment of the tibial component. The medial offset stem of the tibial component may impinge against the medial wall. Anatomic variations should be evaluated before TKA is attempted. Received for publication on Jan. 6, 1999; accepted on Dec. 2, 1999     

Editorial Commentary: Posterior Tibial Slope: The “Unknown Size” of the Knee Joint

The posterior tibial slope (PTS) plays an immensely important role in almost every orthopaedic operation on the knee joint. The PTS is a decisive factor in the reconstruction of a torn anterior or posterior cruciate ligament, in high tibial osteotomy and, of course, in total knee arthroplasty. It is therefore all the more surprising that in current clinical practice relatively little emphasis is placed on the exact measurement of PTS. If the true value is not known, the influence of the same is pure coincidence. In the coronal plane, it is clinically valid practice to determine the hip–knee–ankle angle and thus to be able to determine the mechanical and anatomical axes at the tibia and femur. In the sagittal plane, however, an in-depth analysis is often dispensed with and only a short lateral knee radiograph is used. Different axes are described to determine the PTS. In addition, it is often overlooked that a determination of the PTS on lateral radiographs can only represent an average, since the medial and lateral tibial plateau shows considerable differences purely anatomically. In the future, we should place more emphasis on an analysis of the sagittal plane in the knee joint including PTS at least as profound as the analysis of the frontal plane. Here, radiographs of the entire lateral tibia must be requested to determine the true axis and thus the true PTS.     

Efficacy Analysis of Selection of Distal Reference Point for Tibial Coronal Plane Osteotomy during Total Knee Arthroplasty: A Literature Review

Total knee arthroplasty is an effective treatment for end‐stage knee osteoarthritis. The tibial platform osteotomy must take full account of the coronal plane, the sagittal plane, and the rotational alignment of the tibial prosthesis. During surgery, individual differences in the coronal alignment of the tibia need to be taken into account as poor alignment after surgery can lead to rapid wear of the tibial platform, reducing the longevity of the prosthesis and adversely affecting quality of life. Intraoperative tibial osteotomies are often performed using extramedullary alignment. When an extramedullary alignment approach is used, the proximal tibial osteotomy guide is usually placed in the medial third of the tibial tuberosity. There is no consensus on the most reliable anatomical landmarks or axes for achieving distal tibial coronary alignment. Anatomical points or reference axes that are highly reproducible and precise need to be identified. From available data it appears that most surgeons use the extensor hallucis longus tendon, the second metatarsal, and the anterior tibial cortex to determine the distal localization point. However, its accuracy has not been confirmed in clinical and radiographic data, and the alignment concept and preoperative planning for total knee arthroplasty has paid more attention to rotational alignment, but there are few studies on the coronal alignment of the tibia. This article reviews the recent use of the distal tibial coronal osteotomy reference point in total knee arthroplasty. However, due to there being only a small number of studies available, the evidence collected is insufficient to prove that a certain reference axis has obvious advantages and a combination of different reference points is needed to achieve the ideal lower extremity force line angle.     

Tibial plateau stress fracture: a complication of unicompartmental knee arthroplasty using 4 guide pinholes

Unicompartmental knee arthroplasty has gained popularity recently as a treatment for unicompartmental tibiofemoral non inflammatory arthritis. Tibial plateau stress fracture after unicompartmental knee arthroplasty (UKA) through guide pin holes placed in the proximal tibia has not been previously reported. In each case in this report, the compressive strength of the proximal tibia was reduced by the drilling of multiple holes for the placement of guide pins and holes for the lugs of the tibia component resulting in fracture through these holes between 3 and 18 weeks (median 8 weeks) post-operatively. In at least one case, the medial tibial cortex was violated by one pin. All cases required revision total knee arthroplasty (TKA). It is intuitive to caution against the use of multiple guide holes in the proximal tibia in UKA. If 3 or more hole pins are deemed necessary, surgeons must be aware of the potential for stress fracture and monitor patients accordingly. Peripheral pins that infract the medial tibial cortex should also be avoided.     

胫骨后倾角的测量及与后交叉韧带生物力学关系的研究进展

胫骨后倾角(tibial posterior slope,TPS)最可靠最便捷的测量方式及与后交叉韧带(posterior cruciate ligament,PCL)的生物力学关系存在较大争议。使用X线测量时,推荐使用下肢全长侧位X线片4等份法,其具有高度的可重复性及在日常诊疗过程的普遍性,但仅仅适用于胫骨旋转在15°以内的患者,当旋转超过30°时,平台内侧轮廓不好辨认,不再适用;若仅仅用于日常诊疗评估,当胫骨旋转角在15°以内时,膝关节侧位X线片也具有一定的参考意义,但精准度不能满足要求较高的临床研究。CT测量方法虽能纠正胫骨旋转,但利用在三维CT重建上放置拟合点来测量的方法只适用于无关节退变的膝关节,较多的骨赘会影响利用拟合点的方式来确定的胫骨平面与真实胫骨平台的符合度,具有一定的局限性。MRI不仅可以纠正胫骨旋转,而且使用胫骨解剖轴作为参考轴可以最大程度减少骨赘的影响从而测量出TPS,是一种较好的测量方式。TPS与PCL的生物力学关系,在胫骨截骨术中增大的TPS通过胫骨前移位间接减轻PCL的张力或直接减轻对PCL的负荷都提示可对其产生保护机制;在保留交叉韧带的全膝关节置换术中,...     

全膝关节置换术中胫骨假体旋转确定方法的比较研究

目的 对目前全膝关节置换术(TKA)中常用的2种确定胫骨假体旋转位置的方法 进行比较,以期为术中胫骨假体的正确旋转放置提供参考.方法 连续行初次单侧TKA手术30例.术中于胫骨截骨面上标识出胫骨前后轴、后交叉韧带中点与胫骨结节中内1/3连线、后交叉韧带中点与ROM技术确定的胫骨前方标志点连线.数码相机垂直于截骨面进行图像摄取后转移至电脑,借助于软件系统分别测量胫骨前后轴与上述2条连线的夹角.结果 胫骨结节中内1/3与后交叉韧带中点的连线同胫骨前后轴之间的平均夹角为(11.3±34)°,ROM技术获得的前方标记点基本位于髌腱内侧缘,其与后交叉韧带中点连线同胫骨AP轴之间的平均夹角为(0.8±2.2)°.结论 国人TKA术中,当以胫骨结节中内1/3为标准行胫骨假体旋转放置时,有导致胫骨假体相对于股骨假体外旋过度的可能.当术中进行了正确的股骨假体旋转放置及软组织松解和平衡后,采用ROM技术能够获得更为正确的胫骨假体旋转放置.     

Alignment in total knee arthroplasty following failed high tibial osteotomy

In total knee arthroplasty (TKA) following failed high tibial osteotomy, the mechanical axis does not intersect the center of the tibial component if the tibia has been resected perpendicular to the anatomical axis. Therefore, tibial resection referencing the predicted postoperative mechanical axis instead of the tibial shaft axis is advocated. To obtain the optimal tibial resection, characteristics of the tibial proximal deformity were measured radiographically and predicted postoperative lower limb alignment was calculated using full-length, weight-bearing, lower limb anteroposterior radiographs. Two finite element analysis models also were examined. The proximal tibia was resected perpendicular to the tibial shaft axis in model 1, and perpendicular to the predicted postoperative tibial mechanical axis in model 2. When the proximal tibia was resected perpendicular to the tibial shaft axis, the predicted lower limb mechanical axis was significantly shifted medially to the center of the tibial joint surface. The results of the finite element analysis reflected the medial shift of the lower limb mechanical axis in model 1, where stresses were increased in the medial tibial compartment. Tibial resection referencing the predicted postoperative tibial mechanical axis, instead of the tibial shaft axis, should be performed, especially in cases with a deformed tibia.     

The effect of ankle rotation on cutting of the tibia in total knee arthroplasty

BACKGROUND: Extramedullary alignment guides are commonly used to prepare the tibia during total knee arthroplasty. One disadvantage is that the guide is easily affected by the position of the ankle joint. The tibia may have a rotational mismatch between its proximal and distal ends. We hypothesized that a rotational mismatch might cause incorrect positioning of an extramedullary alignment guide and evaluated such a mismatch on the predicted postoperative coronal alignment of the tibia. METHODS: Fifty-three osteoarthritic knees with varus deformity in fifty-one patients were evaluated with use of computerized tomography scans before total knee arthroplasty. We defined one anteroposterior axis of the ankle joint and five different anteroposterior axes of the proximal aspect of the tibia using three-dimensional bone models from the computerized tomography data. We measured the rotational angle between the anteroposterior axis of the ankle joint and the proximal part of the tibia. The distal end of the extramedullary guide was placed in front of the center of the ankle joint (on the line of the extended anteroposterior axis of the ankle joint), and the proximal end was placed on the line of the extended anteroposterior axis of the proximal part of the tibia. We established spatial coordinates to evaluate the effect of the rotational angle on the predicted postoperative coronal alignment of the tibia and calculated the presumed tibial coronal alignment. RESULTS: The rotational angle was positive (3.6 degrees to 19.7 degrees) for all of the anteroposterior axes of the proximal aspect of the tibia, indicating that the ankle joint was externally rotated relative to the proximal part of the tibia. The predicted tibial coronal alignment was varus (0.5 degrees to 5.1 degrees) for all of the anteroposterior axes of the proximal part of the tibia. CONCLUSIONS: When an extramedullary alignment guide is used to prepare the tibia in total knee arthroplasty, varus alignment of the tibial component can occur because of a rotational mismatch between the proximal part of the tibia and the ankle joint.     

数字化导航模板辅助全膝关节置换的模拟研究

 目的 探讨数字化导航模板辅助全膝关节置换的准确性和可行性。方法 取成年尸体下肢标本 20具,随机分为导航模板组和传统方法组,每组 10具 20个膝关节。导航模板组术前行下肢全长 CT扫描,利用逆向工程软件对 CT数据进行处理,设计与股骨远端和胫骨近端匹配的可定位截骨平面和外旋轴的导航模板,通过快速成型机制作模板实物用于尸体标本的全膝关节置换手术操作。传统方法组按常规全膝关节置换手术操作。术后通过 CT扫描比较两种方法定位的截骨准确性。结果 导航模板与股骨髁和胫骨平台贴合紧密,无明显移动。导航模板组 18个膝关节的股骨远端和胫骨近端截骨面与下肢机械轴垂直,2个膝关节内翻; 17个膝关节后髁截骨面与通髁轴完全平行,3个膝关节有成角。传统方法组 20个膝关节均出现下肢机械轴内外翻,其中 5个膝关节大于 5°; 20个膝关节均出现后髁截骨面与通髁轴成角,其中 10个膝关节大于 3°。结论 导航模板法的股骨远端、胫骨近端和股骨外旋截骨准确性均高于传统手术方法。     

老年性骨关节炎行人工膝关节置换术后 假体旋转对线的定量分析

目的根据不同解剖标志利用CT扫描定量测量人工膝关节置换术后股骨和胫骨假体的旋转对线。方法 2004年对21位合并膝内翻畸形(35个膝)老年性骨关节炎患者(平均年龄73.3岁,范围:60～81岁)行人工膝关节置换手术,术中采用后稳定型固定平台膝关节假体,以股骨后髁轴外旋截骨确定股骨假体旋转定位,综合参考胫骨平台最大覆盖率和胫骨后髁轴确定胫骨假体旋转定位。术后7年进行随访,内容包括病史采集、物理检查,KSS评分和功能评分,负重位膝关节正侧位X光片、髌骨轴位片以及膝关节CT扫描。在CT扫描图像上,根据股骨内外上髁轴(SEA)测量股骨假体旋转角度,分别根据股骨内外上髁轴和胫骨结节内侧1/3测量胫骨假体旋转角度,并以此测算假体的联合旋转角度和旋转不匹配程度。结果对35个膝关节随访7年结果显示,未出现感染、假体透亮带、髌骨脱位或半脱位、髌骨骨折、假体松动等,KSS临床评分平均91分,功能评分平均83分。股骨假体、胫骨假体旋转角度、联合假体旋转角度均呈正态分布;股骨假体平均旋转角度为(3.02±3.88)°;胫骨假体相对于胫骨结节内侧1/3明显处于内旋位(平均17°),相对于SEA旋转角度平均0°,参考两个标志测量的胫骨假体旋转角度之间有显著差异(P=0.000);相对于SEA确定的假体联合旋转角度平均(2.99±7.90)°,相对于胫骨结节内侧1/3确定的假体联合旋转角度平均(-2.64±8.39)°,参考两个参考标志测定假体联合旋转角度之间有显著差异(P=0.005),股骨和胫骨假体旋转不匹配最大程度在10°度左右。结论与胫骨结节内侧1/3做比较,股骨内外上髁轴(SEA)更适合作为CT定量测量人工膝关节置换术后股骨和胫骨假体旋转对线的标志;胫骨平台最大覆盖率和胫骨后髁轴可以作为胫骨假体旋转定位的参考轴线,但具有较大的个体差异性。     

Intraoperative Tibial Anteroposterior Axis Could Not Be Replicated After Tibial Osteotomy in Total Knee Arthroplasty

BackgroundWe evaluated the effect of the anteroposterior (AP) axis of the proximal tibia defined at the cutting surface using an image-free navigation system in total knee arthroplasty.MethodsThis prospective study included 68 patients (79 knees) who underwent total knee arthroplasty. The tibial AP axis was registered in the navigation system with reference to Akagi’s line, connecting the middle of the posterior cruciate ligament to the medial border of the patellar tendon attachment at the tibial joint surface. After proximal tibial osteotomy, the AP axis was replicated as the AP(O) axis. We measured the difference between the AP axis defined at the joint surface and the AP(O) axis defined at the osteotomy surface.ResultsThe AP(O) axis at the osteotomy surface internally rotated 2.0° to the AP axis at the joint surface, and the AP(O) axis outlier (difference to AP axis: >3°) occurred in 54% (43 knees). In the >3° malrotation group, internal malrotation occurred in 37% (30 knees) and external malrotation occurred in 17% (13 knees). In the outlier analysis, the left knees were significantly found in the internal outlier group.ConclusionThe tibial AP axis, connecting the middle of the posterior cruciate ligament to the medial border of the patellar tendon attachment defined at the tibial joint surface, could not be replicated at the tibial osteotomy surface. If the tibial components were set depending only on the AP axis defined at the osteotomy surface, the tibial components could internally rotate and have more outliers, especially in the left knees.     

Adopting the Joint Line Theory for Bone Resection in Cruciate‐Retaining Total Knee Arthroplasty to Prevent Flexion Gap Tightness

BackgroundDuring a conventional measured resection using the posterior reference method for total knee arthroplasty (TKA) in varus knees, proximal tibia is resected from the lateral joint surface for the same thickness as the implant. Distal femur is resected from the worn medial surface for the same thickness as the implant. Posterior femur is resected using the posterior reference method with an external rotation for appropriate degrees. In this situation, although the joint line of the tibia is leveled to the height of lateral joint surface, the posterior joint line of the femur is leveled to the center of medial and lateral posterior condyle, which is a few millimeters lower than the lateral posterior condyle. This discrepancy between the proximal tibia‐posterior femoral joint line causes a tight flexion gap in cruciate‐retaining TKA. Therefore, downsizing of the femur is necessary to adjust the posterior joint line to the level of the lateral condyle.PerspectivesTo avoid this circumstance, the postoperative joint line should be leveled to the center of the original medial and lateral joint surface. Proximal tibia is resected from the lateral joint surface 1 mm to 2 mm thicker than the implant. Distal femur is resected from the worn medial surface 1 mm to 2 mm thinner than the implant. Posterior femur is resected using the posterior reference method with an external rotation for appropriate degrees. In this situation, all the joint lines are leveled to the center of the medial and lateral joint surface. Otherwise, use of an anatomically shaped implant with a physiologic joint line is another option to avoid joint line discrepancy.ConclusionsAdopting joint line theory for bone resection can prevent the flexion gap tightness that likely occurs in cruciate‐retaining TKA.     

Computer-Assisted Total Knee Arthroplasty for Significant Tibial Deformities

Computer-assisted total knee arthroplasty has been demonstrated to provide reproducible limb mechanical alignment within 3° from the neutral mechanical axis. However, restoring proper implant and extremity alignment remains a significant challenge with proximal tibial deficiencies. In this prospective study, we describe the use of computer navigation to quantify the amount of bone loss on the medial or lateral tibial plateau and the use of these data to assess the need for augmentation with metallic tibial wedges. In this study, we demonstrate that computer-assisted total knee arthroplasty in patients with significant tibial deformities can accurately measure severe tibial deformities, predict tibial augment thickness, and provide excellent mechanical alignment and restore the joint line without excessive bony resection, repeated osteotomies, and repeated augment trialing.     

人工全膝关节置换术中胫股关节旋转对线不良的影像学分析

目的分析和探究造成全膝置换术中胫股关节旋转对线不良的可能原因,指导术中选择正确的确定假体部件旋转的方法,以减少术后并发症。方法选择40例正常人的膝关节作为研究对象,男、女各20例,年龄18～42岁。应用螺旋CT扫描(层厚0.5mm)获取膝关节的横断面图像,采用Autocad2004软件测量股骨假体的旋转轴与胫骨假体的旋转轴之间的关系,运用统计学方法分析临床上选择临床上髁轴、外科上髁轴、股骨后髁轴等方法可能存在的潜在的胫股旋转对线不良及其影响程度。结果术中胫骨假体旋转以胫骨结节内、中1/3交界处来确定,而股骨假体旋转分别以临床上髁轴、外科上髁轴、股骨后髁轴外旋3°来确定,可能产生的胫股旋转对线不良的交角平均值分别为2.94°、6.50°、6.83°。结论全膝置换术中利用骨性解剖标志各自独立地确定胫骨假体、股骨假体的旋转对线必然会产生胫股旋转对线不良,而临床上髁轴产生的影响较小。     

Stress analysis after total knee arthroplasty with posterior cruciate ligament-resection type and -retention type prosthesis--with special reference to the significance of retaining the posterior cruciate ligament

Stress analyses in knees replaced with PCL-resection type and PCL-retention type prosthesis under various loading conditions were performed by means of the three-dimensional finite element method. In the knee replaced with the PCL-resection type prosthesis, distribution of large transmitted loads was concentrated in a small area located in front of the stem and under the plateau of prosthesis. The sum of moments of transmitted loads increased as horizontal component loads on the femoral component increased. Large von Mises stresses were distributed in the anterior and proximal parts of the tibia. In the tibia replaced with the PCL-retention type, transmitted loads were observed in the whole area under the plateau and posterior cortex. The sum of moments was significantly smaller than that in the PCL-resection type. Large von Mises stresses were distributed in the posterior and proximal parts of the tibia. It was recommended that the PCL be saved in total knee arthroplasty whenever possible.