如何实现Oxford单髁置换的准确截骨和术后稳定

Oxford单髁置换(UKA)准确截骨、间隙平衡、获得稳定及良好运动轨迹是手术成功的关键.UKA首先建立的是屈曲间隙,然后根据屈曲间隙大小再建立伸直间隙.其间隙平衡是指,在完成内侧胫骨平台截骨后,通过对股骨髁远端研磨调整股骨假体相对于股骨放置的高度,获得相等的屈伸间隙.UKA截骨一环扣一环,不能失误.胫骨截骨量不能过多...     

股骨内髁参数对单髁置换中截骨及假体设计的参考意义

BACKGROUND: Knee-parameter measurements play an important role in the designing of the knee prosthesis. Currently, we have more and more research of the total knee replacement, while uni-condylar knee replacement study is few.  OBJECTIVE: To obtain the parameters of the normal femoral condyles and explore its correlation with osteotomy and prosthesis design of the knee joint during uni-condylar knee replacement. METHODS: Normal knee joints of 60 cases (60 knees) were selected. We measured the parameters by using thin-section CT scan and post-processing techniques, including arc diameter of the lowest point of the femoral condyle on the coronal plane, arc diameter of the distal point of the posterior condyle of the femur on the transverse plane, arc diameter of the distal point of the posterior condyle of the femur on the sagittal plane, and arc diameter of the lowest point of the femoral condyle on the sagittal plane, and analyzed the correlation with sex and height.  RESULTS AND CONCLUSION: The diameter of the arc that passes through the lowest point of femoral medial condyle in the coronal plane was (42.685±1.389) mm. The diameter of the arc that passes through the farthest point of posterior of femoral medial condyle in the cross-section was (42.732±1.440) mm. The diameter of the arc that passes through the lowest point of femoral medial condyle on the sagittal plane was (45.473±1.332) mm. The diameter of the arc that passes through the farthest point of posterior of femoral medial condyle on the sagittal plane was (42.587±1.446) mm. The results illustrate that knee condyle related parameters were positively correlated with height. Parameters in males were significantly greater than in females. The diameter of the arc that passes through the lowest point of femoral medial condyle on the sagittal plane was significantly larger than that of the farthest point of femoral posterior medial condyle on the sagittal plane (P < 0.001). There was no significant difference among the diameter of the arc that passes through the lowest point of femoral medial condyle on the coronal plane, the diameter of the arc that passes through the farthest point of posterior of femoral medial condyle on the cross-section and that of the farthest point of femoral posterior medial condyle on the sagittal plane.       

膝关节剥脱性骨软骨炎MRI诊断

目的 总结膝关节剥脱性骨软骨炎的MRI影像特点,为临床早期诊断提供参考。方法 回顾性分析2012年6月~2017年5月在我院接受MRI检查并经过临床及关节镜证实的17例膝关节剥脱性骨软骨炎患者的MRI影像资料。结果 17例患者中发生于膝关节股骨内侧髁9例,股骨外侧髁3例,胫骨内侧髁3例,髌骨2例,关节腔内游离骨块8例;17例患者均有不同程度膝关节积液。结论 采用合理的MR检查序列,膝关节剥脱性骨软骨炎的MRI表现有明显特征性,为首选检查。     

人体下肢长骨负重关节软骨下松质骨显微硬度分布特征的研究

目的:探讨人体下肢长骨负重关节软骨下松质骨显微硬度的分布特征。方法:选取3具年龄大于40岁的新鲜冰冻尸体标本,取出所有标本的右侧股骨和胫骨,分别于股骨头、股骨内髁、股骨外髁、胫骨内髁、胫骨外髁、胫骨远端距负重区关节软骨面1 cm处,垂直于下肢机械轴切下3 mm厚松质骨样本。使用维氏显微硬度测量系统测量骨组织显微硬度。比...     

Graft position at the femoral condyle affects knee mobility after posterior cruciate ligament replacement

BackgroundIn some cases posterior cruciate ligament (PCL) tears require surgical reconstruction. As the femoral footprint of the ligament is quite large, an ideal graft fixation position on the medial notch wall has not yet been identified. The aim of this study was to compare three different graft fixation positions within the anatomical footprint of the PCL and test it for posterior tibial translation at different knee flexion angles.MethodsIn six human knee specimens a drawer test was simulated on a material testing machine by applying load on the tibia. At three different knee flexion angles (0°, 45°, 90°) knee mobility was examined with respect to tibial posterior translation and stiffness for the following conditions: intact ligaments, detached PCL, three different graft fixation positions on the femoral condyle.ResultsReplacement of the PCL within its femoral footprint restored knee stability in terms of tibial posterior translation. Low graft position showed comparable drawer displacements to the intact condition for all knee flexion angles (p > 0.344). A higher graft position excessively reduced the posterior translation (p < 0.047) and resulted in a restricted knee mobility and a stiffer joint.ConclusionsGraft fixation positions on the femoral condyle play a crucial role in post-operative knee mobility and joint functionality after PCL replacement. Even though all graft fixation positions were placed within the femoral footprint of a native PCL, only the lower position on the medial notch wall showed comparable posterior tibial translation to an intact PCL.     

A case of compression fracture of medial tibial plateau and medial femoral condyle combined with posterior cruciate ligament and posterolateral corner injury

We report a case of compression fracture of anterior margin of medial tibial plateau and medial femoral condyle combined with the posterior cruciate ligament and posterolateral corner disruption. A thirty-seven-year old male had undergone the left knee injury 6 months before. The physical examination revealed positive posterior drawer test and tibial dial test, which evidenced the posterior cruciate ligament and posterolateral corner insufficiency. The plain lateral knee radiographs showed a marginal fracture of the anteromedial tibial plateau and a dimpling on the adjacent part of the medial femoral condyle. On arthroscopy, there were no gross tear of the cruciates, but the posterolateral capsule disclosed stigmata of stretching injury with multiple petechiae and scarring. The compression fracture on the anteromedial side and the stretching injury on the posterolateral side altogether support the mechanism of hyperextension pivoting on the anteromedial side of the knee joint. A small bony lesion around the knee joint should be inspected rigorously with an assumed mechanism of injury for it may herald major ligamentous injury.     

Comparison of medial and lateral posterior femoral condyle articular cartilage wear patterns

Background

While degenerative changes to the articular cartilage of the anterior and distal portions of the femoral condyles have been well studied in the literature, the changes that occur on the posterior femoral condyle are not as clear. The purpose of this study was to assess the difference in articular cartilage thickness between the medial and lateral posterior femoral condyles in knees undergoing unicompartmental knee arthroplasty.

Anterior-posterior stability of the knee by an MR image subtraction method

The purpose of our study was to test the hypothesis that when a shear force was applied posteriorly to the loaded knee in vivo, there would be no relative motion between the tibia and the medial femoral condyle. Siemens 7 Tesla high-resolution MRI machine was used to scan eight healthy male volunteers with the knee at 15° of flexion. Two scans were obtained: the first with a compressive force of 660 N along the tibial long axis and a second with the compressive force and a posterior shear force of 36 N applied to the tibia. Solid models were created of the femur, tibia, and menisci for both loading conditions. The tibial models were superimposed enabling the displacements of the femur and menisci to be determined, relative to a fixed tibia. On average, the lateral femoral condyle displaced anteriorly by 0.66 mm but the medial femoral condyle displaced posteriorly by 0.36 mm. This indicated an axial rotation with a center between the lateral and medial condyles, but closer to the medial. The menisci displaced with the femoral condyles, but there was no indication that the medial meniscus was contributing to the pivoting action. This study supported the concept of medial anterior-posterior stability under weight-bearing conditions, but with structures other than the medial meniscus providing the stability. This study has application to the treatment of knee injuries and to knee arthroplasty design.     

A Geometric Morphometric Analysis of the Medial Tibial Condyle of African Hominids

Although the hominid knee has been heavily scrutinized, shape variation of the medial tibial condyle has yet to be described. Humans, chimpanzees, and gorillas differ in the shape of their medial femoral condyles and in their capacity for external and internal rotation of the tibia relative to the femur. I hypothesize that these differences should be reflected in the shape of the medial tibial condyle of these hominids. Here I use geometric morphometric techniques to uncover shape differences between the medial tibial condyles of humans, chimpanzees, and gorillas. Humans are distinguished from the other two species by having a much more oval‐shaped medial tibial condyle, while those of chimpanzees and gorillas are more triangular in outline. Gorillas (especially males) are distinguished by having more concavely‐curved condyles (mediolateral direction), which is interpreted as an effect of heavy loading through the medial compartment of the knee in conjunction with differences in the degree of arboreality. Anat Rec, 296:1518–1525, 2013. © 2013 Wiley Periodicals, Inc.     

The potential effect of anatomic relationship between the femur and the tibia on medial meniscus tears

Background

The anatomic and the kinematical relationships between the femur and the tibia have been previously examined in both normal and diseased knees. However, less attention has been directed to the effect of these relationships on the meniscal diseases. Therefore, we aimed to investigate the impact of femorotibial incongruence on both lateral and medial meniscal tears.

Materials and methods

A total of 100 images obtained from MRI of 100 patients (39 males and 61 females) were included in the study. Diameters of the medial and the lateral femoral condyles, thicknesses of the menisci, and diameters of the medial and the lateral tibial articular surfaces were measured.

Results

The medial meniscus tear was detected in 40 (40 %) patients. However, no lateral meniscus tear was found. Significant relationships were found between the diameters of the posterior medial femoral condyle and the medial tibial superior articular surface and between the diameters of the posterior lateral femoral condyle and the lateral tibial superior articular surface. The mean values for the diameter of the medial condyle of the femur, the lateral condyle of the femur, the medial superior articular surface of the tibia, and the lateral superior articular surface of the tibia were found to be significantly higher in cases with meniscus tear compared to cases without meniscus tear. However, no significant difference was present regarding the thicknesses of the medial and the lateral menisci. A positive relationship between the diameter of the posterior medial femoral condyle and the tibial medial superior articular surface was found in cases with (n = 40) (r ² = 0.208, p = 0.003) and without tear (n = 60) (r ² = 0.182, p = 0.001). In addition, a significant positive relationship was found between the diameter of the posterior medial femoral condyle and the medial tibial superior articular surface in cases with and without tear.

Conclusion

The impact of femorotibial incongruence on the medial meniscus tear is important for the understanding of the lesions.     

The contact locations in the knee during high flexion

The aim was to determine the contact locations in the knee in a simulation of a deep squatting position, for both neutral and after tibial rotation. A rig was constructed to load the knee under quadriceps action at flexion angles from 135 to 155 degrees flexion, with a mechanism for rotating the tibia internally or externally. Fiducial points on each bone were digitized in each position of the knee. After all of the tests, the entire bone surfaces were digitized, enabling computer reconstructions to be made of the multiple positions. The software then produced color maps of the contact areas. Six cadaveric knees were tested. On the patella, contact occurred over an arcuate band across the superior, lateral and medial edges, including the medial 'odd facet'. On the upper tibia, the medial contact was close to the center of the condyle, while on the lateral side, the contact was posterior. As a result, impingement occurred between the posterior tibial edge and the femoral cortex on the medial side. However, lateral impingement also occurred when the tibia was externally rotated. Due to the stiffness of the knee at these high flexion angles, the maximum tibial rotation between external and internal averaged only 16 degrees. During this rotation, there was twice as much displacement of the lateral contact than the medial contact, indicating greater stability on the medial side. In all rotations, the medial contact moved inwards to engage the intercondylar eminence which appeared to act as the pivot area. The small rotational range implied that correct foot placement was necessary for optimal mechanics during squatting activities.     

Meniscal ossicle: a case report

Meniscal ossicle is a cortical or cancellous tissue with central viable marrow surrounded by meniscal cartilage. We present a case of medial meniscal ossicle at its posterior horn. A 21-year-old male military recruit visited our clinic due to left knee discomfort. He had not undergone any notable injury on the knee, but complained of intermittent catching or giving way without locking. Simple radiographs showed a small round bony fragment at posteromedial side of knee joint. The magnetic resonance imaging revealed an intra-substance lesion of meniscus, whose signal is identical to bone. On arthroscopy, the articular cartilage of medial femoral condyle and tibial plateau appeared degenerative with a groove-like scar. The medial meniscus seemed swollen at the posterior horn, but there was no discernible tear in the adjacent meniscus. After piecemeal removal of meniscal substance, a small osseous fragment was identified, which was evacuated via posteromedial portal. The resection of meniscus amounted to a subtotal meniscectomy. The activities of daily living were possible without any trouble even after 9 months of follow-up. This entity should be distinguished from intra-articular loose body, and included in the differential diagnosis of the incidental findings of small ossified density around knee joint.     

人体膝关节股骨后髁角度的MRI测量

背景：全膝关节置换过程中股骨假体旋转力线良好非常重要,研究显示后髁角度是确定力线的重要依据,后髁角度为股骨后髁轴与股骨手术髁上轴之间角度,MRI测量可清晰显示后髁软骨、外上髁突起及内上髁凹陷,从而保证测量数据的准确。 目的：测量保定北部地区人群中膝关节后髁角度,为临床实施全膝关节置换过程中确定股骨假体旋转力线提供影像学依据。 方法：应用核磁共振机对入选中青年人群膝关节进行扫描,取膝关节伸直中立位,扫描平面垂直于膝关节机械轴,选择T1像上最佳膝关节轴位平面,由两名观察者独自分析图像,通过Bravo viewer 6.0影像软件观察股骨内上髁存在率,画出股骨髁上轴线及后髁线并测量两条轴线之间角度,即股骨后髁角度。 结果与结论：入选人群男性股骨后髁角度为(2.73±1.28)°,女性股骨后髁角度为(2.35±1.37)°,不同性别间差异无显著性意义。提示MRI测量股骨后髁角具有较大优越性,人工全膝关节置换过程中髁上轴线变异性较小,可参照后髁角度定位安装股骨假体,避免膝关节置换后并发症发生。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

Cementless medial Oxford unicompartmental knee replacement. Five-year results from an independent series

BackgroundUnicompartmental knee replacement (UKR) is a common treatment option for patients with advanced medial compartment knee arthritis. The Oxford UKR (OUKR) is the most commonly used implant for partial knee replacement. A cementless Oxford prosthesis was introduced in 2004 aiming to reduce the revision rate by potentially reducing radiolucencies as well as errors of cementation associated with the cemented prosthesis. Whilst results from the designer centre have been reported, there is little independent clinical evidence of outcomes.The aim of this study was to evaluate the survival of the cementless OUKR in a single surgeon series at an independent centre and to assess clinical and radiographic outcomes.MethodsAll patients who received a cementless medial OUKR and had a minimum of five-year follow-up were included in the series. The Oxford knee score was used to evaluate patient outcomes at five years postoperatively. Survival rates, complications and evidence of radiolucencies on plain radiographs were also reviewed.ResultsOne hundred and fifty-eight cementless medial OUKR were implanted in 126 patients. Three patients died and four knees were revised. The five-year survival was 97.4% and the median Oxford knee score was 43 at five years postoperatively. No Complete radiolucent lines were observed on radiographs at one year. Four tibial components subsided.ConclusionsThis independent series shows that low revision rates and excellent results can be achieved with the use of the cementless OUKR at five years. Early subsidence of the tibial component, which is specific to the cementless prosthesis, warrants further investigation.     

不同类型膝关节后稳定型假体髁间截骨量的对比

背景：后稳定型膝关节假体股骨侧需要额外的髁间截骨来容纳胫骨柱和股骨窝结构,髁间窝两侧与股骨体相连处应力集中是骨折好发部位。不同品牌假体不同型号间截骨量的差异并没有具体数据,不便于临床医生在选择假体时参考。 目的：比较临床上常用的后稳定型膝关节假体(进口、国产的6个品牌)髁间截骨数据的不同,为临床假体选择和应用提供依据。 方法：选择目前国内常用的(进口、国产的6个品牌)后稳定型人工膝关节假体,包括Zimmer NexGen LPS、Stryker Scrorpio NRG Knee-Flexed、Depuy PFC Sigma、Smith&nephew Genesis-2 PS、United-U1及威高GKPS。根据截骨模板确定截骨面包括股骨髁前截面、后截部、股骨髁远端截面、后斜截面;对应股骨假体径线包括髁内外径宽、髁前后径宽、股骨髁间窝截骨宽度及深度,对上述数据进行对比测量。 结果与结论：6种膝关节股骨髁假体的前后径/内外径、髁间窝截骨量及形态均存在差异,国外品牌股骨远端前后截骨面间径线较短,对后髁的截骨程度较大。随着应用假体尺寸的增大,所用品牌髁间截骨宽度所致骨量丢失比例均呈下降趋势,无论是小尺寸假体还是大尺寸假体,Stryker Scrorpio NRG Knee-Flexed假体髁间截骨宽度均较小。 6个品牌的膝关节假体截骨尺寸有所不同,以上结果并不足以评价不同假体之间的优劣,但就保留髁间骨储量而言,髁间截骨量少的设计较具优势。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Stressing on the human femoro-patellar joint. I. Components of a vertical and horizontal tensile bracing system

Horizontal and vertical tensions act on the femoropatellar joint. In both knee joints of 60 human corpses the muscles and ligaments participating in the tensile bracing of the knee joint were studied macroscopically. While the structures acting in the vertical direction are very constant, the components participating in horizontal tensile bracing show large variations. Components of vertical tensile bracing are the quadriceps femoris muscle, the ligamentum patellae as well as the vertical patellar retinacula. The active part of horizontal tensile bracing consists of the medial and lateral vastus muscles. The passive components of this system are arranged in three layers. The superficial layer is formed by the fascia lata. The middle layer consists of the horizontal retinacula. A medial horizontal retinaculum was present in one third of our cases. It passes from the medial margin of the patella towards the medial femoral epicondyle. A lateral horizontal retinaculum is demonstrable in all cases studied. It passes horizontally from the lateral margin of the patella and inserts into the deep layer of the iliotibial tract. Insertion of the lateral horizontal retinaculum into the lateral femoral epicondyle was not observed in our material. The third layer is formed by ligaments supporting the joint capsule. These originate from the medial and lateral margin of the patella and pass towards their respective meniscus as well as variably towards the femoral or tibial condyle. These structures are found both medially and laterally in two thirds of the cases studied.     

Interactive effect of femoral posterior condylar offset and tibial posterior slope on knee flexion in posterior cruciate ligament-substituting total knee arthroplasty

Background

This work aimed to evaluate the changes in the femoral posterior condylar offset (PCO) and tibial slope after posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA), and to address the presence of any interactive effect between the two on knee flexion.

Causes of failure of the Kinemax Plus total knee replacement in the first five years

In order to investigate whether any single batch of polyethylene inserts was responsible for premature failure of total knee replacements (TKR), we performed a retrospective database review of 1133 consecutive primary Kinemax Plus TKR performed by 2 surgical teams between January 1992 and January 2001 at our institution. Cases re-operated in any way within 5 years of the index arthroplasty were identified, case notes studied and radiographs reviewed. The causes contributing to the premature failure of the implants were identified where possible and the polyethylene lot numbers were recorded. Nineteen cases were known to have been revised, 7 cases for deep infection of the prosthesis and 12 for aseptic failure. In 10 cases, an identifiable technical error had contributed to the early failure of the implant. In 4 of these cases, there was inadequate tissue balancing in patients with a significant pre-operative valgus deformity. In 2 cases, the tibial base plate was inserted in a varus mal-alignment. There was one extended tibial component, one internally rotated femoral component, one oversized femoral component and one femoral component with inadequate fixation. Two further cases failed aseptically, one with a fracture of the medial tibial plateau and one idiopathic. The lot numbers of the polyethylene inserts were all different. This study confirms that the premature failure rate of the Kinemax Plus TKR is low. Although a "bad batch" of polyethylene has been suggested as a cause for early failure in TKR, in this series, surgical error was the predominant cause.     

一种组合式个性化人工膝关节假体数字化设计方法

目的 提出一种组合式个性化人工膝关节假体结构,解决膝关节股骨肿瘤保肢手术由于截骨位置差异性较大,很难采用标准型人工膝关节假体满足个性化需求的问题。方法 首先将患部关节区域CT数据进行三维重建,并利用MRI增强扫描技术建立肿瘤的三维模型,再通过肿瘤模型与患部关节模型进行位置匹配,在三维模型上确定手术截骨位置,根据截骨尺寸设计个性化的股骨柄与标准股骨髁假体进行有效组合,形成一种组合式个性化人工膝关节假体。结果 根据本文设计方法的结果加工成型,骨科临床医生分析膝关节假体结构与人体膝关节生理结构相符,达到个性化假体设计要求,能够重建患者膝关节功能。结论 这种膝关节假体结构有利于降低个性化膝关节假体设计加工成本,缩短设计加工周期,有望提高患者生命质量。     

Custom-made lateral femoral condyle replacement for traumatic bone loss: A case report

We report the case of a 24 year-old patient who underwent a novel treatment for a lateral femoral condyle fracture. The fracture was associated with extensive joint line depression and not considered suitable for conventional fixation techniques. Existing reconstructive options for such situations include unicondylar osteoarticular allograft, arthrodesis and arthroplasty. However, these techniques all present significant disadvantages, particularly in the management of active patients. We report our medium-term results following reconstruction using a custom-made lateral femoral condyle hemiarthroplasty replacement. Follow-up at 48 months revealed an excellent, pain-free level of function, with an Oxford Knee Score of 46/48, a Knee Society knee score of 87/100 and a functional score of 100/100. Radiographs demonstrated no evidence of prosthesis loosening or migration and no erosion of the lateral tibial plateau. The technique allows preservation of the remaining normal joint surface of the femur that may promote earlier and better restoration of function. Furthermore, the isolated condyle hemi-replacement maximises bone preservation, facilitating future anticipated revisions. The procedure presents an attractive alternative to other surgical options and their attendant problems. Further investigation into this technique is required before widespread adoption, though such studies will be compromised by the relative rarity of patients in whom the technique is indicated.