Development of cell-seeded patellar tendon allografts for anterior cruciate ligament reconstruction

Patellar tendon (PT) allografts for anterior cruciate ligament (ACL) reconstruction are potentially immunogenic and incorporate slowly compared with autografts. Our tissue-engineering approach to improve allograft efficacy is to (1) remove intrinsic cells from the graft to reduce antigenicity and then (2) seed the graft with extrinsic cells to improve ligamentization. To remove cells, tendons were soaked in 1% extraction solutions of tri(n-butyl)phosphate (TBP) or sodium dodecyl sulfate (SDS) for various time periods (24-72 h) and rinsed exhaustively. After treatment, we measured tendon cellularity, crimp structure, and mechanical properties. Treatment with either SDS or TBP removed approximately 70-90% of the intrinsic PT cells. Mechanical properties of treated PTs were similar to those of controls, despite changes in appearance. TBP- and SDS-treated PTs were then seeded with fibroblasts and cultured for up to 2 weeks in vitro. Fibroblast proliferation was retarded on SDS-treated PTs; in contrast, TBP-treated PTs supported cell proliferation similar to that of untreated controls. Extrinsic fibroblasts were successfully cultured on the TBP-treated PTs in vitro, creating viable tissue-engineered grafts potentially useful for ACL reconstruction. These modified allografts have the potential to be developed into mechanically functional delivery vehicles for cells, gene therapy vectors, or other biological agents.     

The natural history of anterior cruciate ligament reconstruction using patellar tendon autograft

The purpose of this study was to review the results of ACL reconstruction using a patellar tendon graft placed ‘over the top’ plus a Macintosh lateral tenodesis, examining changes in knee laxity and functional status with increasing time. There were 74 patients operated on over an 11 year period, and divided into four groups for analysis according to postoperative time. There was a significant and progressive increase in side-to-side laxity difference with time, although functional status did not change significantly, indicating a lack of correlation between objective clinical tests and subjective findings. The highest Lysholm, Tegner and IKDC scores were at 4–5 years after operation, when 60% of patients were at their pre-injury level of sports activity. However, there was always a very significant difference between actual and desired Tegner activity levels for the group as a whole. While there was a significant correlation between degenerative changes and the time between injury and reconstruction, there was no correlation with postoperative time: this provides evidence that ACL reconstruction can protect the knee from later degeneration.     

Anatomical bases of patellar tendon grafts used in anterior cruciate ligament reconstruction

In 24 fresh specimens the blood-supply of the infrapatellar fat-pad was investigated by injection. In some of the specimens, Clancy's pedicled patellar tendon graft for anterior cruciate ligament reconstruction had been performed before injection. The fat-pad is supplied by vessels forming a plexus supplying the tendon. In the tendon grafts injected after Clancy's procedure, no vessels were found penetrating the patellar tendon at its patellar and tibial attachments. Filled vessels were found by histologic methods and the Spalteholz technique.     

Collagen fibrillogenesis and mRNA levels in the maturing rabbit medial collateral ligament and patellar tendon

This study compared collagen fibril diameter and mRNA changes in a subset of molecules involved in collagen fibrillogenesis during postnatal development and at maturity of rabbit medial collateral ligament (MCL) and patellar tendon (PT). Tissue was analyzed by RT-PCR for mRNA levels and collagen fibril diameters were measured using transmission electron microscopy. Collagen fibril diameters increased from 3 to 14 weeks with mean fibril diameters of PT significantly greater than MCL at 9, 12, and 14 weeks and maturity. RT-PCR analysis showed decorin and lumican mRNA levels were significantly higher in PT than MCL at all ages. Type I collagen, MMP-11, and procollagen C proteinase enhancer mRNA levels also were higher in the PT than the MCL between 3 and 14 weeks but not at maturity. Further understanding of collagen fibrillogenesis by studying protein synthesis and matrix turnover during maturation may provide insight into the mechanism(s) by which fibrils accrete in maturing connective tissues and how they are altered during healing following injury.     

Anterior knee symptoms after reconstruction of the anterior cruciate ligament using patellar tendon as a graft

We have reviewed 74 patients, at an average follow-up of nearly 3 years, following anterior cruciate ligament reconstruction with the central third of the patellar tendon to assess the incidence and severity of anterior knee symptoms, not only pain but also other symptoms related to the front of the knee. Sixty-two percent of patients had some degree of pain. In addition, there was numbness in 85%, patello-femoral crepitus in 47% and swelling in 26% of patients. Only one patient felt that the front of the knee was normal. Eleven percent felt that these symptoms were a significant problem.     

自噬在兔部分损伤前交叉韧带和内侧副韧带中的差异

目的：确定兔前交叉韧带和内侧副韧带部分损伤后自噬的存在,并比较损伤后不同时间两者之间自噬的表 达差异,探讨其愈合能力差异与自噬的关系。方法： 3 月龄健康雄性新西兰大白兔18 只,随机选取3 只作为对照 组,其余兔建立前交叉韧带和内侧副韧带部分损伤模型, 随机分为5 组,各组分别在造模后3 d、1 周、2 周、4 周、 6 周取材。H-E 染色观察损伤部位形态学变化,透射电镜观察损伤部位超微结构变化,免疫印迹检测自噬相关蛋 白Beclin 1、LC3Ⅱ/Ⅰ、p62 表达水平,RT-PCR 检测自噬相关基因Beclin 1、ATG-5 mRNA表达水平。结果：在 部分损伤后3 d、1 周、2 周、4 周、6 周5 个时间点,前交叉韧带和内侧副韧带均未表现出明显的愈合趋势,观察 到自噬小体的存在。与对照组相比,自噬相关蛋白Beclin 1、LC3Ⅱ/Ⅰ、p62 在前交叉韧带中的高表达更为显著, 在内侧副韧带中的表达更早恢复至正常水平,并继续降低;自噬相关基因ATG-5、Beclin 1 在前交叉韧带中始终 处于高表达状态,峰值出现在1 周,内侧副韧带高表达峰值出现在2 周,此后逐渐恢复至正常水平。结论： 兔前 交叉韧带、内侧副韧带部分损伤后自噬相关因子的表达随时间推移,总体呈现先升高后降低的变化趋势,损伤后 不同时间点前交叉韧带、内侧副韧带中自噬的表达存在明显差异,推测前交叉韧带损伤后自噬的过度激活可能导 致其内源性修复障碍。     

Compact platelet-rich fibrin scaffold to improve healing of patellar tendon defects and for medial collateral ligament reconstruction

BackgroundPlatelets are one of the most biocompatible and cost-effective sources of growth factors. Attention is being paid to autologous platelets and platelet-rich plasma. We developed a novel compact platelet-rich fibrin scaffold (CPFS) that was produced from blood and calcium gluconate only. The objective of this study was to investigate the potential of CPFS as a provisional scaffold in two rabbit models.MethodsIn the first rabbit model, the central half of the patellar tendon was resected bilaterally. Allogenic CPFS was attached to the defect in the right knee, while the left knee was untreated. In the other model, the medial collateral ligament was removed bilaterally. The ligament of the right knee was reconstructed with allogenic CPFS, whereas the left knee was untreated.ResultsAfter 12 weeks, the ultimate failure load and stiffness were higher for the right patellar tendon than for the left patellar tendon in the former model. It was found that CPFS promoted ligament repair tissue in contrast with that on the untreated side in the latter model. The ultimate failure load of the CPFS repair tissue at 20 weeks was 78% of that in healthy controls of the same age.ConclusionsCPFS enhanced the healing of tendons and ligaments.Clinical relevanceCPFS has the potential to accelerate healing of tendons and ligaments as a provisional bioscaffold or a material for graft augmentation.     

Reconstruction of patellar tendon rupture after anterior cruciate ligament reconstruction: a case report

Patellar tendon rupture following use of its central third for anterior cruciate ligament (ACL) reconstruction is a rare disabling injury that is technically difficult to repair. We report one case of patellar tendon rupture after harvesting the mid-third for ACL reconstruction. A number of different surgical methods exist for reconstructing patellar tendon ruptures. Here we report a case using a bone-tendon-bone (BTB) allograft, followed by a multiple-wire loop reinforcement with no postoperative immobilisation. One year after operation, our patient had regained full knee extension and flexion. Insall Salvati index on the operated side was identical to the uninjured side. The patient had good quadriceps strength, and isokinetic muscle testing showed no deficit in his right leg. He was able to return to professional handball without limitation.     

转基因兔骨髓间充质干细胞对异体跟腱重建前交叉韧带生物力学特性的影响

目的分别观察转PDGF-BB、VEGF165和TGFβ1基因的兔骨髓间充质干细胞(mesen chymal stem cells,MSCs)施加于异体跟腱重建兔前交叉韧带(anterior cruciate ligament,ACL)的影响,探讨改善和加强异体移植物重建ACL的途径。方法40只成年新西兰大白兔随机分为5组,每组8只。选用经Gamma射线照射,-80℃储存的同种异体跟腱进行前交叉韧带的重建。1组为对照组,2组为细胞组(MSCs),3组为经逆转录病毒转染稳定表达PDGF-BB的MSCs(PDGF-BB组),4组为经腺病毒转染稳定表达VEGF165的MSCs(VEGF165组),5组为经腺病毒转染稳定表达TGFβ1的MSCs(TGFβ1组)。各组细胞混合l00μL纤维蛋白胶粘附于重建韧带表面,术后12w取材。结果组织学观察发现,VEGF165组新生血管和成纤维细胞浸润高于其他各组。生物力学测试证明,PDGF-BB组和TGFβ1组移植物的最大载荷刚度、吸收能和最大拉张强度明显较对照组增强(P<0.05),细胞组和VEGF165组最大载荷、刚度和吸收能虽高于对照组,但无显著差异(P>0.05),VEGF165组拉断位移大于对照组(P<0.05)。所有实验组移植物、正常ACL和跟腱都在体部断裂。结论转VEGF165基因的MSCs可增加重建韧带的血管,但对生物力学功能无改善;转PDGF-BB基因和TGFβ1基因的MSCs有加速重建韧带成熟的作用。     

挤压螺钉固定自体髌韧带重建前交叉韧带的生物力学研究

目的 :对挤压螺钉固定自体骨 髌韧带 骨 (B PT B)移植重建前交叉韧带 (ACL)术进行生物力学评价。方法 :对正常和挤压螺钉固定自体B PT B移植重建ACL术后状态的 6例新鲜尸体标本 ,进行膝关节屈曲 15°、3 0°、90°胫骨前移刚度和屈膝 90°胫骨前移强度测试。结果 :挤压螺钉固定自体B PT B移植重建ACL术后 ,膝关节成屈曲状态时胫骨前移刚度明显大于正常状态 ;强度则明显小于正常状态 ,约为其3 2 %。结论 :挤压螺钉固定自体B PT B移植重建ACL术后可早期开始非负重功能锻炼 ,肌力锻炼以闭链训练为宜。     

An ultrastructural study on anterior cruciate ligament reconstruction using autogenous patellar tendon grafts in dogs

An ultrastructural study was undertaken concerning morphological changes within the autografted patellar tendon (PT) after being transplanted to the anterior cruciate ligament (ACL) in mongrel dogs. After 4 weeks, the arrangements of both large and small collagen fibrils in the PT graft became disordered, and the number of inflammatory cells increased. However, the same PT grafts revealed postsurgical signs of newly-produced collagen fibrils around activated fibroblasts at 12 to 24 weeks. At 52 weeks after the transplantation, small collagen fibrils increased in both number and density, showing a remarkable morphological similarity to the collagen fibrils of normal ACL. These data indicate that the characteristics of the PT graft eventually resemble those of a normal ACL. This paper was presented in part at the Combined Meeting of the Orthopedic Research Societies of the USA, Japan and Canada in Banff, Alberta, Canada, October, 1991.     

自体与同种异体肌腱重建膝关节前交叉韧带的比较

背景：关节镜辅助下重建前交叉韧带的移植物主要有自体移植物、同种异体移植物和人工韧带3种,关于移植物的选择,存在较多争议。 目的：评估自体健侧腘绳肌腱和同种异体肌腱两种移植物在膝关节前交叉韧带重建中的效果。 方法：纳入2007-01/2009-01在承德医学院附属医院骨科就诊的经关节镜检查证实为前交叉韧带损伤的患者70例(70膝),分别采用自体健侧腘绳肌腱和同种异体肌腱重建前交叉韧带,记录膝关节Lysholm功能评分、KT-1000测量值及不良反应。 结果与结论：患者随访18~24个月,均未发生血管神经损伤,无感染、植入物断裂等并发症;同种异体肌腱移植患者有2例膝关节引流管口持续渗出,经换药半月后愈合,其余切口均一期愈合。末次随访时,自体健侧腘绳肌腱和同种异体肌腱重建患者的Lysholm评分均显著提高,双侧膝关节前向松弛度差值显著减少,且两种方法比较差异无显著性意义(P > 0.05)。说明应用自体健侧腘绳肌腱与同种异体肌腱重建膝关节前交叉韧带疗效相当,效果满意。     

Pseudoaneurysm of the medial inferior genicular artery following anterior cruciate ligament reconstruction with hamstring tendon autograft

Vascular injuries associated with arthroscopic surgery of the knee are uncommon. Pseudoaneurysm of the medial inferior genicular artery after hamstring tendon ACL reconstruction has not been reported yet. Diagnosis can be obtained clinically if continuous filling of the drain, hard and painful swelling of the lower leg, pulsatile swelling or mass in the region of the affected joint, are present. Definitive confirmation of the diagnosis can be achieved by sonography and angiography. The method of treatment consists of simple surgical wound exploration and ligation of the affected vessel.     

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。     

Nerve injury during anterior cruciate ligament reconstruction: A comparison between patellar and hamstring tendon grafts harvest

Background

Tendon harvesting for anterior cruciate ligament reconstruction often injures sensory branches of the saphenous nerve. The reports on the prevalence of these injuries are scarce, while the implications on patient satisfaction are not known. Our objective was to compare the prevalence of sensory nerve injuries in patellar to hamstring autograft harvesting for anterior cruciate ligament reconstructions and follow up their postoperative course.

组织工程化前交叉韧带在运动损伤修复中应用

背景：运动员前交叉韧带的损伤极难彻底恢复,降低运动寿命。 目的：总结组织工程化前交叉韧带在运动损伤修复中的研究现状和最新进展。 方法：采用计算机检索维普数据库和PubMed数据库1994-01/2010-12相关文章,纳入28篇与运动性前交叉韧带损伤及组织工程韧带相关的文章,重点对组织工程前交叉韧带重建的研究进展、前交叉韧带种子细胞的来源、细胞因子在前交叉韧带重建中的应用及组织工程前交叉韧带附丽的基础研究4个方面进行探讨。 结果与结论：运动中前交叉韧带损伤后自体愈合能力极差,对于运动员伤后痊愈造成极大困难。组织工程前交叉韧带近些年来飞速发展,具有良好的应用和发展前景。但在实际应用过程中,组织工程化种子细胞的选择、支架材料的构建和组织工程前交叉韧带附丽的基础研究三者有机相互融合,并合理应用生长因子,才能在临床上起到最佳治疗效果,最终达到修复和重建前交叉韧带的目的。     

股直肌腱中1/3与前交叉韧带的生物力学比较

背景：股直肌腱已成为重建前交叉韧带的重要替代物。 目的：比较股直肌腱中1/3和前交叉韧带的生物力学特性。 方法：标本于死者死亡后9.0~10.0 h解剖取下股直肌腱和前交叉韧带,取下后立刻用以生理盐水浸湿的纱布包裹,密封后置于-20 ℃冰箱内保存。实验前取出标本,切取试样,股直肌腱和前交叉韧带每组共10个试样。 结果与结论：股直肌腱中1/3的单位模量是前交叉韧带的63%,单位最大载荷为63%,提示股直肌腱中1/3是适合作为交叉韧带重建物的。      

自体腘绳肌腱与人工韧带加强系统重建前交叉韧带的比较

目的比较自体腘绳肌腱(HT)和人工韧带加强系统(LARS)重建前交叉韧带(ACL)的效果。方法选择61例ACL断裂患者(均为单侧断裂),其中男性37例,女性24例;年龄17~57岁,平均年龄36岁。采用自体HT重建ACL30例(HT组),采用LARS重建ACL31例(LARS组)。按Lysholm评分系统及KT-2000检查评估功能。结果全部病例均获随访,随访时间26~30个月。Lysholm评分术后2年HT组和LARS组分别为(90.80±8.87)分、(91.70±6.54)分;KT-2000测试膝关节移动距离分别为(2.58±2.18)mm、(2.39±2.09)mm。两组膝关节Lysholm评分在术后均较术前改善,差异有统计学意义(P0.05)。两组间术后Lysholm评分及膝关节稳定性KT-2000检查比较,差异无统计学意义(P0.05)。结论两种移植物均能够获得满意的临床效果,明显改善膝关节功能,LARS是一种良好的替代移植物。     

Comparison of drop jump landing biomechanics and asymmetry among adolescents with hamstring,patellar and quadriceps tendon autografts for anterior cruciate ligament reconstruction

Background

Adolescent anterior cruciate ligament reconstruction (ACLR) commonly utilizes hamstring (HT), patellar (PT) or quadriceps (QT) tendon autografts, but consensus is lacking regarding optimal graft choice. This study compared landing biomechanics and asymmetries among ACLR patients with HT, PT and QT grafts and uninjured controls.