前后交叉韧带同时重建固定角度实验研究

目的探讨采用自体半腱肌肌腱同时重建前交叉韧带(anterior cruciate ligament,ACL)和后交叉韧带(posterior cruciate ligament,PCL)移植肌腱固定时膝关节屈曲最佳角度。方法清洁级6～8月龄新西兰大白兔24只,雌雄不限,体重(2.5±0.2)kg,根据重建韧带固定时膝关节屈曲角度不同,随机分为3组(n=8)。取双侧后肢半腱肌肌腱,同时重建右后肢PCL及ACL,并分别于膝关节屈曲90°(A组)、60°(B组)、30°(C组)位固定。术后观察实验动物一般情况;术后3个月时,采用空气栓塞法处死实验动物,取膝关节远、近端各10 cm长肢体,行伸屈等长实验、前后位移实验、膝关节内外旋转实验。结果实验动物均存活至实验完成。3组间ACL及PCL最大位移比较,差异均无统计学意义(P>0.05)。各组前、后方位移均<1 mm,提示前、后稳定性均良好;A组屈曲30°时前方位移及屈曲90°时后方位移均较C组大,差异均有统计学意义(P<0.05)。A组内、外旋转角度与C组比较,差异均有统计学意义(P<0.05);其余各组间比较,差异均无统计学意义(P>0.05)。结论同时重建兔ACL及PCL,以屈曲60°行韧带固定效果最佳。     

关节镜下同种异体胫前肌腱同期重建前后交叉韧带的疗效分析

目的 探讨关节镜下运用同种异体胫前肌腱同期重建前、后交叉韧带(ACL、PCL)的方法和疗效.方法 2007年1月至2009年1月共收治13例膝关节ACL、PCL损伤患者,男9例,女4例;年龄23～57岁,平均37.5岁;左膝8例,右膝5例.均采用关节镜下同种异体胫前肌腱重建ACL、PCL,股骨端用可吸收界面挤压螺钉固定,胫骨端用Intrafix固定.同时处理合并的半月板、侧副韧带损伤.术前按照国际膝关节文献委员会(IKDC)综合评价患膝功能:均为D级.Lysholm评分平均为(42.0±1.3)分.结果 13例患者术后获14～27个月(平均20.4个月)随访,患膝功能均明显改善,1例体榆仍有阳性体征,无免疫排斥反应发生.末次随访时IKDC综合评价结果:A级6例(46%),B级5例(38%),C级2例(16%).末次随访时Lysholm评分平均为(93.0±2.7)分,与术前相比差异有统计学意义(P<0.05).结论 关节镜下同期完成ACL、PCL重建,能及时恢复膝关节的正常解剖关系,临床疗效较好.     

Ultrasound diagnosis of pathology of the anterior and posterior cruciate ligaments of the knee joint

Summary We established a method of diagnosing pathologic conditions of both the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) by using ultrasound. Normal ACL and PCL were delineated as hyperechoic images on the screen in sagittal and transverse sections. On the other hand, no image of the ligament could be seen when the ligament was ruptured. We examined nine ACL and five PCL injuries by our method. This is a safe and an effective method of determining the rupture of ACL and PCL.     

膝关节镜下自体腘绳肌腱和同种异体肌腱移植重建前交叉韧带对比观察

目的：探讨关节镜下同种异体肌腱和自体腘绳肌腱重建前交叉韧带的疗效。方法：收集32例前交叉韧带损伤病例,单纯前交叉韧带（ACL）损伤29例,与后交叉韧带（PCL）同时损伤3例。分为2组,同种异体肌腱重建15例,男12例,女3例,年龄23～61岁;自体腘绳肌腱重建17例,男11例,女6例,年龄17～57岁。用可吸收或钛挤压螺钉固定,观察并记录治疗后的症状、体征变化和Lysholm评分以及术后6个月的功能康复情况。结果：全部病例均获得随访,时间6～8个月,所有病例无膝前区疼痛,临床症状消失,膝关节功能得到改善。同种异体肌腱重建前交叉韧带5例患者仍出现Lachman征阳性体征,其中1例产生严重的排斥反应,关节镜复查韧带完全吸收。2组患者治疗后Lysholm评分分别为平均（88.5±7.2）分和（93.2±8.5）分,差异无统计学意义（P〉0.05）。结论：关节镜下两种方法重建前交叉韧带都有较好的疗效,同种异体肌腱重建交叉韧带早期有更多的症状,有明显的个体差异,重建交叉韧带尽可能选用自体腘绳肌腱。     

关节镜下同种异体胫前肌腱同期重建前后交叉韧带

膝关节前交叉韧带(anterior cruciate ligament,ACL)与后交叉韧带(posterior cruciate ligament,PCL)同时断裂常见于高能量损伤,且伴有膝关节其他结构损伤,导致严重膝关节不稳及功能障碍,因此对膝关节ACL和PCL同时损伤的患者应积极采用手术治疗.自体肌腱(骨-髌腱-骨或半腱肌)重建交叉韧带疗效肯定,但对于ACL和PCL司时损伤的患者,自体肌腱受限于取材有限和增加供区并发症的危险.因此,我们于2003年1月至2007年1月应用异体胫前肌腱重建修复23例膝关节ACL和PCL同时断裂的患者,随访效果良好,现报告如下.     

A follow-up study of arthroscopic combined reconstruction of anterior and posterior cruciate ligaments with allograft patellar tendon

Objective： To evaluate the therapeutic effect of combined reconstruction of anterior cruciate ligament （ ACL ） and posterior cruciate ligament （ PCL ） simultaneously by using allograft patellar tendon under arthroscopy. Methods： From May 2003 to November 2005, 10 cases of ruptured ACL and PCL were fixated with compressed screws and reconstructed under arthroscopy with allograft patellar tendon simultaneously. The clinical results were evaluated according to IKDC, Lysholm, and Tegner clinical rating scales. Results. All patients were followed up for 12-30 months （mean： 18 months ）. At the last follow-up, there was no knee extension limitation and knee flexion was between 120° and 135°, with an average of 128.38°. The Lysholm score of the 10 cases was 66. 5 ± 5. 6 before operation and 89.8 ± 3.4 at last follow up. The difference was statistically significant （ P 〈 0.01 ）. The average Tegner activity score decreased from 6.9 ± 1.7 （ range ： 4-9 ） before injury to 5.5 ± 1. 6 （rang： 2-9） at the follow-up （P=0.53）. At the end of follow-up, IKDC score was graded as A in 4 cases （40.0 % ）, B in 5 （50.0 % ）, and C in 1 （10.0%）. Of the 10 patients, 8 returned to the same sports level as before injury and 2 were under the level. Conclusion. Arthroscopic combined reconstruction of ACL and PCL with allograft patellar tendon has the advantages of minimal trauma in surgery and reliable satisfactory outcome.     

关节镜下双股半腱肌腱单端固定法重建膝交叉韧带

目的观察膝关节镜下双股半腱肌腱单端固定法重建膝前、后交叉韧带的方法及疗效,探讨其优缺点。方法应用双股半腱肌腱,单端固定,重建前交叉韧带损伤38例,后交叉韧带24例。结果所有患者术后随访6～36个月,平均18个月。按Lysholm膝关节评分标准,由术前43分提高到术后93分。结论双股半腱肌腱,单侧固定法重建前、后交叉韧带具有创伤小,操作简便,是重建前、后交叉韧带的理想方法之一。     

后交叉韧带损伤的诊疗进展

后交叉韧带(posterior cruciate ligament,PCL)的损伤在膝关节损伤中较少见,并且很少产生膝关节不稳的典型症状,常常发生漏诊及误诊,或者不予重视,患者得不到及时治疗,导致膝关节不稳.继发半月板、软骨损害和骨性关节炎.因此,对于这些患者,能够得到早期诊断及最佳治疗至关重要.本文主要对PCL损伤的诊断和治疗方法进行综述.     

关节镜下深低温冷冻异体韧带重建后交叉韧带的疗效分析

目的探讨关节镜下深低温冷冻异体韧带重建后交叉韧带(PCL)的方法和疗效。方法2003年9月～2006年3月,采用深低温冷冻异体韧带重建方法治疗12例膝关节PCL断裂患者。术前及术后6个月用Lysholm和Gillquist评分评定膝关节功能及患肢运动水平。结果12例患者铁6～14个月(平均10个月)随访,术前Lysholm和Gillquist评分平均53分(40～65分),术后6个月Lysholm和Gillquist评分平均87分(60～95分),本组优7例,良4例,中1例,总优良率91．7%。临床症状消失,行走步态正常,关节活动度正常。结论膝关节镜下采用异体韧带重建PCL,可同时达到解剖重建和等长重建的双重目的,可有效改善膝关节稳定性,手术损伤小、康复快,疗效肯定。     

Histologic evaluation of posterior cruciate ligaments from osteoarthritic knees

It is controversial whether posterior cruciate ligament-retaining or posterior cruciate ligament-sacrificing (-substituting) implants should be used in total knee arthroplasty. The use of posterior cruciate ligament-retaining implants implies that the residual ligament is functional, and presumably normal, but few studies have been conducted to elucidate the histologic appearance of the posterior cruciate ligament taken from osteoarthritic knees. The purposes of the current study were (1) to evaluate the histologic appearance of posterior cruciate ligaments excised from osteoarthritic knees during primary total knee arthroplasty and to compare their appearance with posterior cruciate ligaments from knees of cadavers that were not operated on; and (2) to determine whether a correlation exists between the histologic appearance of the posterior cruciate ligament and the clinical status of the patients studied. Twenty-six posterior cruciate ligament specimens from patients with osteoarthritis and four specimens from cadavers were evaluated with the use of light and electron microscopy. Posterior cruciate ligaments from osteoarthritic knees showed greater degeneration than those from cadavers by light microscopy. Age greater than 60 years was associated with decreased collagen diameter in posterior cruciate ligaments from osteoarthritic knees as determined by electron microscopy. With the number of specimens available, the authors could not find a significant correlation between tibiofemoral alignment and mean collagen diameter or percentage of collagen occupancy. The extent of tissue degeneration of the posterior cruciate ligament could not be predicted by clinical findings. Additional studies identifying the mechanical competency of the posterior cruciate ligament in osteoarthritis would be valuable.     

The gross morphology of torn human anterior cruciate ligaments in unstable knees.

To evaluate the presence and incidence of reattachments of torn human anterior cruciate ligaments (ACL), we prospectively investigated 101 patients undergoing arthroscopic ACL reconstruction to study the intra-articular morphology of ACLs under circumstances in which functional healing had failed. Results showed that roughly 72% of these unstable knees had reattachment of the torn ACL to the posterior cruciate ligament (PCL). Eighteen percent had no signs of ACL reattachment but only 2% of previously torn ACLs were absent. These results suggest that even in chronic situations in which the knee remains functionally unstable, human ACLs rarely resorb. It also suggests that torn human ACLs commonly reattach in the knee, mainly to the PCL via a process that is consistent with scarring. While the function of these reattachments is clearly inadequate in people with unstable knees because of a combination of reattachment location, scar quantity, or quality, these results nonetheless show that the intra-articular environment in humans often maintains ACL stumps and it is not totally inhibitory to ACL reattachment via some biological process.     

Immunohistological detection of relaxin binding to anterior cruciate ligaments

Relaxin, a member of the insulin-like growth factor family, alters collagen metabolism in fibroblasts. It was hypothesized that relaxin interacts with the anterior cruciate ligament (ACL), contributing to its elasticity. Twelve ACL specimens were collected from reconstruction surgeries, sectioned, rinsed, and exposed to rh-relaxin overnight. Polyclonal antirelaxin antibodies, in conjunction with HRP-AEC, localized areas of tissue binding. Controls were used to infer binding specificity. Staining was present in the positive control and all 12 ACL specimens; little or no staining occurred in the negative controls. These data suggest that relaxin binding to the ACL is specific, indicative of a receptor-mediated event.     

Microstructural organization of human and bovine cruciate ligaments

Human and bovine anterior cruciate ligaments studied with the SEM demonstrate fascicular bundle and connective tissue sheath components. In the human, collagen fibers of the connective tissue sheath, although approximately the same diameter as the fascicular fibers, have an orientation suggestive of a binding rather than a tensile function. While both elements have tensile properties, it is hypothesized that the contribution from the sheath component is minimal and, consequently, detailed studies of the tensile properties of ligaments will produce meaningful data when related to the appropriate cross-sectional areas. In direct contrast to the human counterpart, the SEM appearance of bovine cruciate ligaments is tendon-like, characterized by very dense subfasciculi surrounded by very thin connective tissue sheaths.     

In situ forces of the anterior and posterior cruciate ligaments in high knee flexion: an in vitro investigation.

The function of the anterior and posterior cruciate ligaments (ACL and PCL) in the first 120 degrees of flexion has been reported extensively, but little is known of their behavior at higher flexion angles. The aim of this investigation was to study the effects of muscle loads on the in situ forces in both ligaments at high knee flexion (>120 degrees). Eighteen fresh-frozen human knee specimens were tested on a robotic testing system from full extension to 150 degrees of flexion in response to quadriceps (400 N), hamstrings (200 N), and combined quadriceps and hamstrings (400 N/200 N) loads. The in situ forces in the ACL and PCL were measured using the principle of superposition. The force in the ACL peaked at 30 degrees of flexion (71.7 +/- 27.9 N in response to the quadriceps load, 52.3 +/- 24.4 N in response to the combined muscle load, 32.3 +/- 20.9 N in response to the hamstrings load). At 150 degrees, the ACL force was approximately 30 N in response to the quadriceps load and 20 N in response to the combined muscle load and isolated hamstring load. The PCL force peaked at 90 degrees (34.0 +/- 15.3 N in response to the quadriceps load, 88.6 +/- 23.7 N in response to the combined muscle load, 99.8 +/- 24.0 N in response to the hamstrings load) and decreased to around 35 N at 150 degrees in response to each of the loads. These results demonstrate that the ACL and PCL carried significantly less load at high flexion in response to the simulated muscle loads compared to the peak loads they carried in response to the same muscle loads at other flexion angles. The data could provide a reference point for the investigation of non-weight bearing flexion and extension knee exercises in high flexion. Furthermore, these data could be useful in designing total knee implants to achieve high flexion.     

Replacement of human anterior cruciate ligaments with pig ligaments: a model for anti-non-gal antibody response in long-term xenotransplantation

BACKGROUND: Understanding anti-non-gal antibody response is of significance for success in xenotransplantation. Long-term anti-non-gal response in humans was studied in patients transplanted with porcine patellar tendon (PT) lacking alpha-gal epitopes, for replacing ruptured anterior cruciate ligament (ACL). METHODS: Porcine PTs were treated with recombinant alpha-galactosidase to eliminate alpha-gal epitopes and with glutaraldehyde for moderate cross-linking of collagen fibers. The processed pig PTs were implanted to replace ruptured ACL in patients. RESULTS: In five of six evaluable subjects, the xenografts have continued to function for over two years and passed all functional stability assessments. Thus, processed porcine PT seems to be appropriate for replacing ruptured human ACL. Enzyme-linked immunosorbent assay and Western blot studies indicated that all subjects produced anti-non-gal antibodies against multiple pig xenoproteins, but not against human ligament proteins. Production of anti-non-gal antibodies peaked two to six months posttransplantation and disappeared after two years. CONCLUSIONS: These antibodies contribute to a low-level inflammatory process that aids in gradual xenograft replacement by infiltrating host fibroblasts that align with the pig collagen "scaffold" and secrete collagen matrix. The assays monitoring anti-non-gal antibodies will help to determine whether long-term survival of live organ xenografts requires complete suppression of this antibody response.