Ganglion cysts of the posterior cruciate ligament

Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals.     

The dynamic relations of the posterior cruciate ligament

This study attempts to identify the immediate relations of the posterior cruciate ligament (PCL) during different degrees of knee flexion. Cadaveric dissection and magnetic resonance imaging of living subjects found that the popliteal artery is tethered to the oblique popliteal ligament behind the knee, but is free to move above and below this level. Movement of the neurovascular structures as a whole occurs during motion of the knee. These factors have implications for surgical practice, not only for PCL reconstruction, but also for any procedure requiring instrumentation to the back of the knee, such as total knee arthroplasty.     

A simple constitutive model for the Scapholunate ligament

A simple constitutive equation is presented to describe the non-linear load-displacement behavior of the Scapholunate ligament. The model is based on an elastic large strain probabilistic constitutive equation and has been formulated offering three characteristic constants. Experimental data from five human cadaveric Scapholunate ligaments were used to corroborate the accuracy of the model. Good correlation (r(2)=0.90-0.98) was found with the experimental data. Representative characteristic constants for the human Scapholunate ligament based on the model were determined.     

An anatomical study of the caprine posterior cruciate ligament

Introduction

The pathophysiology and treatment techniques for posterior cruciate ligament (PCL) injuries and diseases are currently controversial and leave much room for improvement. However, the caprine PCL anatomy is not well known.

A novel MIS technique for posterior cruciate ligament avulsion fractures

Objective

Open surgical approaches to treat tibial avulsion fractures of the posterior cruciate ligament (PCL) often use large incisions involving extensive muscle dissection and retraction. The objective of this study was to describe a new mini-invasive approach targeting the fractured zone, to minimize surgical dissection and improve recovery and rehabilitation.

LARS人工韧带同时重建前、后交叉韧带

目的探讨关节镜下LARS（Ligament Advanced Reinforcement System，LARS）人工韧带同时重建前（An-terior cruciate ligament，ACL）、后交叉韧带（posterior cruciate ligament，PCL）的方法和临床疗效。方法从2006年1月至2007年4月，用LARS人工韧带同时重建ACL、PCL2例。应用Lysholm功能评分表评估膝关节功能，采用抽屉实验检查膝关节前后松弛度。结果2例均获得随访，随访时间分别为8月、3月。2例患者术后患膝关节不稳定症状消失，胫骨后坠征阴性，前、后抽屉试验阴性。膝关节功能评估采用Lysholm功能评分标准，术前平均分别为45．6±7．6分，术后平均为80．3±9．1分。结论关节镜下应用LARS人工韧带同时重建ACL、PCL可更好地恢复膝芙节的稳定性，且创伤小，并发症少，近期疗效满意，但远期效果仍需进一步观察。     

Magnetic resonance imaging of the posterior cruciate ligament in flexion

Background

Posterior cruciate ligament (PCL) injuries of the knee are common and sometimes difficult to diagnose. Magnetic resonance imaging (MRI), performed using standard orthogonal plane views, is the investigation of choice. It can be particularly difficult to differentiate acute partial and complete tears and identify elongation of chronic healed tears. The aim of the paper is to describe a new method of positioning the patient with the knee flexed at 90°, allowing the PCL to be visualised in a position of greatest length and tension which may assist in differentiating and identifying these injuries.

Tibial inlay for posterior cruciate ligament reconstruction: A systematic review

Although no consensus has been reached regarding the management of PCL deficiency, in vitro and in vivo studies have investigated whether the tibial inlay technique restores the anatomical site of insertion of the PCL, prevents elongation, stretching, graft failure, and improves long-term PCL stability. A systematic search using PubMed, Ovid, the Cochrane Reviews, and Google Scholar databases using ‘posterior cruciate ligament tear’, ‘Tibial inlay technique’ and ‘posterior cruciate ligament reconstruction’ as keywords identified 71 publications, of which 10 were relevant to the topic, and included a total of 255 patients. The tibial inlay technique restores the anatomic insertion site of the PCL, eliminates the killer turn effect, and places the graft at lower potential risk for abrasion and subsequent rupture. It has the disadvantages of increased operating time and risk to the posterior neurovascular structures. There was no evidence of an association between outcome results and Coleman methodology score, but the Coleman methodology scores correlated positively with the level-of-evidence rating. The methodological quality of the studies included has not improved over the years. Given the few reported published findings, we cannot ascertain whether this procedure may provide a consistent alternative to commonly used PCL surgical strategies. The lack of published randomized clinical trials and few reported findings did not allow to ascertain whether the tibial inlay for posterior cruciate ligament reconstruction may provide a consistent alternative to commonly used PCL surgical strategies and to demonstrate procedure efficacy.     

膝关节后交叉韧带断裂对内侧副韧带组织学的影响

背景：通过比较Ⅰ型胶原、Ⅲ型胶原相对数量和Ⅰ/Ⅲ型胶原的比值可以一定程度上判断韧带的组织学性能。 目的：观察膝关节后交叉韧带断裂兔保持较低生理负荷和活动度时内侧副韧带组织学的变化。 方法：24只成年雄性家兔双侧膝关节配对为自身对照,实验侧行后交叉韧带完全切断,对照侧只暴露后交叉韧带而不切断,造模后第8,16,24,40周随机处死6只实验兔。进行苏木精-伊红染色,天狼猩红染色检测Ⅰ型和Ⅲ型胶原的相对数量。 结果与结论：①苏木精-伊红染色结果：8,16,24周两组内侧副韧带胶原分布、排列无明显差别;40周时实验组胶原纤维较对照组稀疏。②天狼猩红染色结果：8,16,24周实验组内侧副韧带的Ⅰ型和Ⅲ型胶原纤维总和分别较对照组显著增加(P < 0.05);40周时实验组较对照组显著减少(P < 0.05);8周实验组和对照组之间内侧副韧带的Ⅰ/Ⅲ型胶原纤维的比值差异无显著性意义(P > 0.05);16,24,40周时实验组比值显著分别小于对照组(P < 0.05)。说明兔膝关节后交叉韧带损伤后短期内对内侧副韧带组织学特性无明显影响,随着时间延长,组织学特性显著下降。     

膝关节后交叉韧带损伤对侧副韧带生物力学的影响

背景：目前对膝关节后交叉韧带损伤后的研究多集中于软骨、后外侧结构及关节的松弛度等方面。 目的：观察后交叉韧带断裂对膝关节内、外侧副韧带生物力学的影响。 方法：取12具正常成人新鲜尸体膝关节标本,在200 N载荷下,测试膝关节屈曲0°,30°,60°,90°位时,内、外侧副韧带中点的应变,后将12具标本的后交叉韧带全部切断再进行相同的测试。 结果与结论：膝屈曲0°和30°位时,后交叉韧带断裂前后内、外侧副韧带中点的应变均为压应变,且差异无显著性意义 (P > 0.05);膝屈曲30°~90°位时,内侧副韧带中点的应变随着角度增加而逐渐增大;膝屈曲60°和90°位时,后交叉韧带断裂后拉应变较断裂前明显增大(P < 0.05),其中内侧副韧带中点的应变均为拉应变,而外侧副韧带中点的应变在后交叉韧带完整情况下膝屈曲60°时为压应变。说明后交叉韧带完全断裂对30°内的膝关节运动无明显影响,但是随着屈曲角度的增加,内、外侧副韧带受到的影响逐渐增大。     

Arthroscopic posterior cruciate ligament reconstruction with allograft versus autograft

Introduction

The aim of the study was to compare and analyze retrospectively the outcomes of arthroscopic posterior cruciate ligament reconstruction with autograft versus allograft.

Material and methods

Seventy-one patients who underwent arthroscopic posterior cruciate ligament reconstruction with an autograft or allograft met our inclusion criteria. There were 36 patients in the autograft group and 35 patients in the allograft group. All the patients were evaluated by physical examination and a functional ligament test. Comparative analysis was done in terms of operation time, incision length, fever time, postoperative infection rate, incidence of numbness and dysesthesia around the incision, as well as a routine blood test.

Results

The average follow-up of the autograft group was 3.2 ±0.2 years and that of the allograft group was 3.3 ±0.6 years; there was no significant difference (p > 0.05). No differences existed in knee range of motion, Lysholm scores, International Knee Documentation Committee standard evaluation form and Tegner activity score at final follow-up (p > 0.05), except that patients in the allograft group had a shorter operation time and incision length and a longer fever time (p < 0.05). We found a difference in posterior drawer test and KT-2000 arthrometer assessment (p < 0.05). The posterior tibia displacement averaged 3.8 ±1.5 mm in the autograft group and 4.8 ±1.7 mm in the allograft group (p < 0.05). The incidence of numbness and dysesthesia around the incision in the autograft group was higher than that in the allograft group (p < 0.05). There was no infection postoperatively. The white blood cells and neutrophils in the allograft group increased more than those in the autograft group postoperatively (p < 0.05).

Conclusions

Both groups of patients had satisfactory outcomes after the operation. However, in the instrumented posterior laxity test, the autograft gave better results than the allograft. No differences in functional scores were found.     

In-situ forces in the human posterior cruciate ligament in response to posterior tibial loading

Although some investigators have referred to the human posterior cruciate ligament (PCL) as the center of the knee, it has received less attention than the more frequently injured anterior cruciate ligament (ACL) and medial collateral ligament (MCL). Therefore, our understanding of the function of the PCL is limited. Our laboratory has developed a method of measuring thein-situ forces in a ligament without contacting that ligament by using a universal force-moment sensor (UFS). In this study, we attached a USF to the tibia and measuredin-situ forces of the human PCL as a function of knee flexion in response to tibial loading. At a 50-N posterior tibial load, the force in the PCL increased from 25±11 N (mean±SD) at 30° of knee flexion to 48±12 N at 90° of knee flexion. At 100 N, the corresponding increases were to 50±17 N and 95±17 N, respectively. Of note, at 30° knee flexion, approximately 45% of the resistance to posterior tibial loading was caused by contact between the tibia and the femoral condyles, whereas, at 90° of knee flexion, no resistance was caused by such contact. For direction of thein-situ force, the elevation angle from the tibial plateau was greater at 30° of knee flexion than at 90° of knee flexion. The data gathered on the magnitude and direction of thein-situ force of the PCL should help in our understanding of the dependence of knee flexion angle of the forces within the PCL.     

膝关节后交叉韧带解剖研究及临床意义

目的:对后交叉韧带的解剖结构进行观察研究,为临床诊治提供解剖学基础。方法:对42例人膝关节标本PCL进行观察,测量其长度、宽度和厚度以及附着区的形态;应用显微外科技术对14具新鲜冷冻标本进行解剖;对PCL行组织学观察,掌握其微观结构。结果:PCL长(33.8±1.3)mm(31.0～37.0mm),两端粗大,最窄处位于中间。PCL是不可分割的完整韧带,由许多纤维组成并发生扭转,纤维束相互穿插融合。组织切片示PCL近端和远端纤维分布松散,中段紧密。结论:PCL是完整的韧带,各束之间有交叉纤维联结。     

Haemorrhagic synovial cyst of the posterior cruciate ligament: a case report

Cystic lesions arising in relation to the cruciate ligaments of the knee joint may become symptomatic and they can cause restriction of joint movement. We report here on a case of haemorrhagic synovial cyst arising from the posterior cruciate ligament with extension into the posterior compartment of the knee joint. We treated this lesion using the arthroscopic posterior-posterior triangulation technique. The histopathological findings of the synovial cyst were also verified. We would like to suggest that the posterior cruciate ligament synovial cyst should be considered in the differential diagnosis of cystic lesions that arise from the posterior compartment of the knee joint.     

Quantitative evaluation of nutritional pathways for the posterior cruciate ligament and the lateral collateral ligament in rabbits

The cruciate ligament of the knee receives its nutrition from a direct vascular supply and by permeation of nutrients from the synovial fluid. The contributions of these two routes as nutritional pathways are not known in detail. In this study, we injected [³H]methyl glucose as a tracer intravenously or directly into the knee of rabbits. Tracer concentrations in plasma, synovial fluid, the posterior cruciate ligament (PCL), and the lateral collateral ligament (LCL) were analysed by a pharmacokinetic compartment model. The contribution of [³H]methyl glucose permeation from the synovial fluid during steady state was calculated at 44.3% in the PCL and at 39.0% in the LCL. Although these results indicated that more than half the nutrition for both ligaments is provided by its vascular supply, synovial fluid permeation is also an important transport route for small molecules for the PCL and the LCL, which is an extra-articular structure.     

后交叉韧带在损伤后膝关节中作用的生物力学研究

目的：通过测试韧带切除对膝关节稳定性的影响，为后交叉韧带损伤的临床诊治提供实验依据。方法：采用１４例新鲜尸体膝关节，经三维运动试验机施加５种力偶，使膝关节产生三维运动。首先对完整标本进行测试，测得的结果为自身对照组，然后测试分别切除韧带后的三维变化。结果：经立体摄像机计算机图像处理得到正常膝关节的角位移运动范围为：前伸１８．３°±３．３°，外展３．４°±２．０°，内收４．８°±１．８°，外旋２３．９°±２．４°，内旋２６．６°±５．３°；单纯后交叉韧带切除后膝关节的角位移运动范围无限制性变化；继外侧副韧带切除后再行后交叉韧带切断时，膝关节的外展、内收运动出现限制性增大（Ｐ＜０．０５），而其旋转运动出现极显著性增大（Ｐ＜０．０１）。结论：后交叉韧带对稳定状态下的膝关节不影响其角运动。在膝关节处于不稳定状态时，后交叉韧带则具有限制内收、外展及旋转运动的作用。后交叉韧带不仅是胫骨后移的第一限制韧带，而且还是膝关节内收、外展及旋转的第二限制韧带。     

关节镜下自体肌腱及同种异体肌腱重建膝关节前后交叉韧带

背景：自体肌腱移植重建膝关节前后交叉韧带已广泛应用,但是供区容易出现并发症,同种异体肌腱移植越来越多应用于重建膝关节前后交叉韧带,是一种重要的替代材料。 目的：比较关节镜下自体肌腱及同种异体肌腱移植重建膝关节前后交叉韧带的临床疗效差异。 方法：40 例前后交叉韧带损伤患者分为2组：自体肌腱组为自体半腱肌及股薄肌重建膝关节前后交叉韧带,异体肌腱组为应用由山西骨组织库提供的同种异体肌腱重建膝关节前后交叉韧带。 结果与结论：全部病例均获得6个月以上随访,最长随访时间36个月。重建前后两组大腿周径患健侧差值、Lachman 试验、中立位前抽屉试验(ADT)和国际膝关节评分委员会(IKDC)、Lysholm 及Tegner 评分差异均有显著性意义(P < 0.01),两组间术后各项指标差异均无显著性意义(P > 0.05)。结果表明,自体肌腱与单纯深低温冷冻同种异体肌腱移植在重建膝关节前后交叉韧带疗效无明显差异。     

The effect of obesity on complications following isolated posterior cruciate ligament reconstruction

BackgroundThis study assessed the risk of 30-day complications for obese patients compared to non-obese patients undergoing isolated posterior cruciate ligament (PCL) reconstruction.MethodsFrom 2006 to 2019, the National Surgical Quality Improvement Program database was queried for patients undergoing isolated PCL reconstruction. Two patient cohorts were defined: patients with obesity (BMI ≥ 30.0 kg/m²) and patients without obesity (BMI < 30 kg/m²). Patients’ baseline demographics and medical comorbidities were collected and compared between the cohorts. Postoperative outcomes were assessed using bivariate and multivariate analyses.Results414 patients underwent PCL reconstruction. 258 patients (62.3%) were non-obese and 156 patients (37.7%) were obese. Obese patients were more likely to be older, have a higher American Society of Anesthesiologists classification, and have hypertension compared to non-obese patients (p < 0.05 for all). The rates of superficial surgical site infections, wound dehiscence, transfusion necessity, deep vein thrombosis, and re-operation were not significant between obese and non-obese patients. Following adjustment on multivariate analyses, relative to patients without obesity, those with obesity had an increased risk of admission to the hospital overnight (OR 1.66; p = 0.048).ConclusionsTo our knowledge, this is the first study to evaluate obesity on complications in isolated PCL reconstruction. Our results and the heterogeneity in the literature indicate that obesity significantly impacts the rates of hospital readmission for PCL reconstruction. Therefore, surgeons should carefully weigh the risks and benefits of operating on obese patients and plan accordingly as obese patients may require postoperative hospital admission after PCL reconstruction.Level of Evidence: III.     

膝关节前交叉韧带重建兔模型的建立

背景：传统前交叉韧带重建造模腱骨界面愈合缓慢,造模时间较长。   目的：通过在腱骨界面注入以纤维蛋白胶为载体的重组人骨形态发生蛋白2复合物,建立造模周期更短、更完善的兔膝关节前交叉韧带重建动物模型。 方法：取成年新西兰兔同侧半腱肌肌腱作为自体移植材料,建立双侧前交叉韧带重建动物模型,建模后随机分为模型组、纤维蛋白胶组,空白对照组和正常组。模型组在移植腱骨隧道界面注射填充以纤维蛋白胶作为载体的重组人骨形态发生蛋白2,纤维蛋白胶组在重建术后腱骨界面仅填充纤维蛋白胶,空白对照组在重建术后腱骨界面不作任何填充,正常组则不予手术,保留正常的前交叉韧带。各组分别于术后第4和8周取材,进行生物力学检测。 结果与结论：模型组最大载荷和刚度在术后4和8周与纤维蛋白胶组和空白对照组相比均增强(P < 0.01)。由此可见,实验成功建立了双侧前交叉韧带重建动物模型,以纤维蛋白胶作为载体的重组人骨形态发生蛋白2可以在术后早期提高腱骨界面的最大载荷和刚度,促进了腱骨界面的愈合,缩短了重建动物模型的实验周期。     

膝关节后纵隔与后交叉韧带下止点的解剖关系及临床意义

目的 探讨膝关节后纵隔与后交叉韧带(PCL)下止点的解剖关系及其在PCL重建中的临床价值. 方法 解剖22例新鲜冷冻膝关节,将PCL在屈膝90°下按纤维张力的不同分为前外束和后内束,解剖出它们在胫骨上的足迹,并用墨汁标记足迹的轮廓;使用带标尺的数码相机测量PCL前外束、后内束胫骨止点中心点与后纵隔的水平距离,并同时测量两束止点中心点与外侧胫骨平台后软骨缘上表面的垂直距离. 结果 膝关节存在一个从前至后的纵隔结构,其前方与脂肪垫、翼状皱襞或黏膜韧带相连,中间位于前、后交叉韧带之间,后方形成膝关节的后纵隔.在22个膝关节中,8个膝关节的后纵隔从PCL的外缘绕过以后止于后关节囊,占36.36%;14个膝关节的后纵隔在PCL前方分叉,包绕PCL后止于后关节囊,占63.64%.PCL前外束胫骨止点中心点距离后纵隔内侧的水平距离(0.90±2.40)mm,距离外侧胫骨平台后软骨缘上表面的垂直距离是(3.25±1.20)mm.后内束胫骨止点中心点距离后纵隔内侧的水平距离为(4.35±2.46)mm,距离外侧胫骨平台后软骨缘上表面的垂直距离为(6.91±1.57)mm. 结论 膝关节后纵隔与PCL下止点的解剖关系密切,后纵隔可以成为PCL单束重建和双束重建手术中胫骨止点定位的重要解剖标志之一.