术后早期活动对同种异体关节移植后关节软骨保护作用的实验研究

目的采用同种异体关节移植动物模型,于术后采用不同处理方法进行对照实验,探讨同种异体关节移植后早期活动对关节软骨的保护作用。方法选用生长条件相同的6月龄新西兰大耳白兔10只(雌雄不限,体重2.5～3.0 kg)作为供体,取其一侧半膝关节,经深低温冻存处理后移植于取下股骨侧半膝关节的6月龄青紫蓝兔(雌雄不限,体重2.5～3.0 kg)膝关节处,术后分别给予早期活动(术后2周,早期活动组,n=5)或持续石膏固定6周(持续固定组,n=5);并取供体对侧半膝关节设立空白对照组(未经任何处理,n=5)和冻存对照组(经深低温处理2周,n=5)。术后分别行大体、X线片及组织学观测,观察同种异体关节软骨的变化情况。结果大体观察示,早期活动组实验兔关节活动良好;持续固定组实验兔关节活动受限明显。X线片示,术后当天、术后2周同种异体关节供体骨端与受体骨端对合整齐、对位对线良好;术后6周,早期活动组3只实验兔受体和供体骨端略有成角畸形,持续固定组对位及对线仍良好。HE染色示,早期活动组同种异体半膝关节标本软骨细胞数量和形态基本正常,偶见核碎裂及核溶解;持续固定组同种异体半膝关节标本中软骨细胞大量减少,大部分细胞核溶解消失,软骨基质中大量纤维组织增生。细胞存活率检测示,早期活动组细胞存活率(49.66%±2.15%)显著高于持续固定组(20.68%±1.24%),比较差异有统计学意义(P<0.05)。扫描电镜观察示,早期活动组同种异体半膝关节标本可见软骨细胞细胞核核膜尚完整,染色质凝聚、边集,线粒体及粗面内质网肿胀;持续固定组同种异体半膝关节标本可见软骨细胞细胞膜消失,软骨细胞与周围基质界限不清,核膜破裂,染色质及细胞质内细胞器消失。结论同种异体关节移植术后进行早期功能活动对兔关节软骨有保护作用,但不能完全阻止软骨退变。     

Surgical technique for articular cartilage transplantation to full-thickness cartilage defects in the knee joint

Focal arthritic defects in the knee lead to pain, swelling, and dysfunction. Treatment of the defects has includeddrilling, abrasion, and grafting. This report describes our surgical technique of autogenous articular cartilage grafting of arthritic and traumatic articular cartilage lesions. Articular cartilage grafting can be performed as a single arthroscopic outpatient procedure. The mixture of articular cartilage and cancellous bone appears to provide a supportive matrix for cartilage formation. Pain relief is excellent if careful surgical technique and a defined rehabilitation program is followed. Further collagen typing data and additional biopsies will reveal more about the durability of the newly formed cartilage.     

Comparison of meniscal allograft transplantation techniques using a preclinical canine model

Meniscal allograft transplantation (MAT) can be a safe, effective treatment for meniscal deficiency resulting in knee dysfunction, leading to osteoarthritis (OA) without proper treatment with 5‐year functional success rates (75%‐90%). While different grafts and techniques have generally proven safe and effective, complications include shrinkage, extrusion, progression of joint pathology, and failure. The objective of this study was to assess the functional outcomes after MAT using three different clinically‐relevant methods in a preclinical canine model. The study was designed to test the hypothesis that fresh meniscal‐osteochondral allograft transplantation would be associated with significantly better function and joint health compared with fresh‐viable or fresh‐frozen meniscus‐only allograft transplantations. Three months after meniscal release to induce meniscus‐deficient medial compartment disease, research hounds (n = 12) underwent MAT using meniscus allografts harvested from matched dogs. Three MAT conditions (n = 4 each) were compared: frozen meniscus–fresh‐frozen meniscal allograft with menisco‐capsular suture repair; fresh meniscus–fresh viable meniscal allograft (Missouri Osteochondral Preservation System (MOPS)‐preservation for 30 days) with menisco‐tibial ligament repair; fresh menisco‐tibial–fresh, viable meniscal‐tibial‐osteochondral allografts (MOPS‐preservation for 30 days) with menisco‐tibial ligament preservation and autogenous bone marrow aspirate concentrate on OCA bone. Assessment was performed up to 6 months after MAT. Pain, comfortable range of motion, imaging, and arthroscopic scores as well histological and cell viability findings were superior (P < .05) for the fresh menisco‐tibial group compared with the two other groups. Novel meniscal preservation and implantation techniques with fresh, MOPS‐preserved, viable meniscal‐osteochondral allografts with menisco‐tibial ligament preservation appears to be safe and effective for restoring knee function and joint health in this preclinical model. This has the potential to significantly improve outcomes after MAT.     

Meniscal allograft transplantation for symptomatic knee after meniscectomy of torn discoid medial meniscus: Report of three cases

In symptomatic discoid medial meniscus, partial meniscectomy is the principal treatment method and can yield promising short-term results. However, unlike the nondiscoid meniscus, discoid medial meniscus is frequently associated with horizontal cleavage tears, attributable to the presence of myxoid degeneration in the intrameniscal substance, in that it may potentially occur deteriorating long-term results because of re-tearing of remaining meniscus or secondary degeneration of cartilage of the medial compartment after meniscectomy. We experienced three rare cases of retear or secondary degeneration of cartilage of the medial compartment after meniscectomy for two patients with torn bilateral meniscus. Both patients were highly active young males. Meniscal allograft transplantation in complicated discoid medial meniscus was performed. At 2 years after meniscal allograft transplantation, clinical outcomes were improved with a normal range of motion. Orthopedic surgeons should recommend activity modification to prevent possible complicated injury of the discoid medial meniscus. Meniscal allograft transplantation may be an alternative option in highly active young patients undergoing complicated discoid medial meniscus to diminish pain, improve knee function, and prevent or delay degeneration.     

骨保护素对兔骨关节炎关节软骨的保护效应

目的 观察关节腔内注射骨保护素对兔骨关节炎关节软骨组织形态的保护作用.方法 将60只雄性新西兰大白兔随机分为三组,每组20只.骨保护素组行左侧膝关节前十字韧带离断术,术后4周于左膝关节腔内注射骨保护素溶液0.1 ml,每周注射5次,共注射8周;磷酸盐缓冲液组于前十字韧带离断术后4周注射等剂量磷酸盐缓冲液;假手术组显露前十字韧带后缝合切口.术后12周处死动物取左膝关节标本,行大体形态学Pelletier评分,切片番红染色后行Mankin软骨评分并测量软骨厚度.结果 大体观察骨保护素组股骨髁软骨评分(1.80±0.89)分,胫骨平台软骨评分(1.80±0.77)分,均低于磷酸盐缓冲液组[分别为(3.10±0.97)、(3.20±0.77)分],与假手术组比较差异无统计学意义.组织学观察骨保护素组的软骨结构(2.65±0.88)分、软骨细胞(1.35±0.71)分、番红染色(1.83±0.83)分、潮线完整性(0.30±0.47)分及Mankin软骨评分总分(6.13±1.97)分,均低于磷酸盐缓冲液组[分别为(4.52±1.09)、(1.85±0.63)、(2.80±0.75)、(0.65±0.49)、(9.83±1.98)分].骨保护素组Mankin评分总分高于假手术组,但四个分项评分与假手术组的差异无统计学意义.骨保护素组软骨厚度(371.84±38.94)μm,大于磷酸盐缓冲液组(255.09±74.82)μm,小于假手术组(404.68±15.97)μm,差异均有统计学意义.结论 骨保护素对关节软骨具有保护效应,可延缓骨关节炎进展.保护效应表现为减轻滑膜炎症反应、减少关节边缘骨赘形成及在一定程度上阻止软骨厚度丢失.     

不同手术方式对关节软骨影响的实验研究

[目的]了解3种不同手术方式对活体关节软骨的影响。[方法]用光镜、扫描电镜及生物化学方法观察3种手术后不同时点兔膝关节软骨的结构及基质蛋白多糖的变化。[结果]3种手术对关节软骨都会造成损伤，使蛋白多糖的含量降低，暴露组造成不可逆性损伤，保护组和灌注组造成可逆性损伤，灌注组软骨损伤最轻、恢复最快。[结论]3种关节手术均会造成关节软骨损伤，关节灌注组的影响最小。     

Comparison of osmotic swelling influences on meniscal fibrocartilage and articular cartilage tissue mechanics in compression and shear

Although the contribution of the circumferential collagen bundles to the anisotropic tensile stiffness of meniscal tissue has been well described, the implications of interactions between tissue components for other mechanical properties have not been as widely examined. This study compared the effects of the proteoglycan‐associated osmotic swelling stress on meniscal fibrocartilage and articular cartilage (AC) mechanics by manipulating the osmotic environment and tissue compressive offset. Cylindrical samples were obtained from the menisci and AC of bovine stifles, equilibrated in phosphate‐buffered saline solutions ranging from 0.1× to 10×, and tested in oscillatory torsional shear and unconfined compression. Biochemical analysis indicated that treatments and testing did not substantially alter tissue composition. Mechanical testing revealed tissue‐specific responses to both increasing compressive offset and decreasing bath salinity. Most notably, reduced salinity dramatically increased the shear modulus of both axially and circumferentially oriented meniscal tissue explants to a much greater extent than for cartilage samples. Combined with previous studies, these findings suggest that meniscal proteoglycans have a distinct structural role, stabilizing, and stiffening the matrix surrounding the primary circumferential collagen bundles. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:95–102, 2012     

A rabbit model demonstrates the influence of cartilage thickness on intra‐articular drug delivery and retention within cartilage

For evaluation of new approaches to drug delivery into cartilage, the choice of an animal model is critically important. Since cartilage thickness varies with animal size, different levels of drug uptake, transport and retention should be expected. Simple intra‐articular injection can require very high drug doses to achieve a concentration gradient high enough for drug diffusion into cartilage. New approaches involve nanoparticle delivery of functionalized drugs directly into cartilage; however, diffusion‐binding kinetics proceeds as the square of cartilage thickness. In this study, we demonstrate the necessity of using larger animals for sustained intra‐cartilage delivery and retention, exemplified by intra‐articular injection of Avidin (drug‐carrier) into rabbits and compared to rats in vivo. Penetration and retention of Avidin within cartilage is greatly enhanced by electrostatic interactions. Medial tibial cartilage was the thickest of rabbit cartilages, which generated the longest intra‐cartilage half‐life of Avidin (τ_1/2 = 154 h). In contrast, Avidin half‐life in thinner rat cartilage was 5–6 times shorter (τ_1/2 ～ 29 h). While a weak correlation (R² = 0.43) was found between Avidin half‐lives and rabbit tissue GAG concentrations, this correlation improved dramatically (R² = 0.96) when normalized to the square of cartilage thickness, consistent with the importance of cartilage thickness to evaluation of drug delivery and retention. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:660–667, 2015.     

骨软骨镶嵌移植术与微骨折术治疗膝关节软骨损伤的疗效比较

目的:对比评估微骨折术与自体骨软骨镶嵌移植术治疗膝关节软骨损伤的临床疗效差异。方法 :回顾性分析2011年2月至2016年2月采用微骨折术或自体骨软骨镶嵌移植术治疗且随访时间≥2年的71例膝关节股骨远端关节面软骨损伤患者资料,按手术方式不同分为两组:微骨折组33例,男20例,女13例,年龄(28.1±4.2)岁;移植组38例,男26例,女12例,年龄(27.8±3.5)岁。采用Lysholm评分,美国特种外科医院膝关节评分(Hospital for Special Surgery Knee Score,HSS),Ahlb覿ck骨关节炎分级系统进行评估,并记录术后并发症。结果 :微骨折组与移植组的Lysholm评分,分别由术前62.9±6.8、60.3±7.5提高到术后的77.0±5.4、85.8±5.6 (P0.05);HSS评分分别由术前81.5±7.6、79.6±8.6改善为88.0±4.7、91.9±4.7(P0.05)。移植组术后Lysholm评分与HSS评分,均高于微骨折组(P0.05)。移植组发生切口浅表感染1例。随访未发现患者出现膝关节骨关节炎。结论:自体骨软骨镶嵌移植术与微骨折术治疗膝关节软骨损伤均安全、有效,但自体骨软骨镶嵌移植术比微骨折术临床疗效更佳。     

Influence of secondary damage to menisci and articular cartilage on return to sports after anterior cruciate ligament reconstruction

The influence of secondary damage to joint structures (menisci and articular cartilage) on return to sports activities following anterior cruciate ligament (ACL) reconstruction was investigated. Two hundred and sixty athletes who had undergone ACL reconstruction with the Leeds-Keio artificial ligament and had achieved satisfactory joint stability and range of motion were involved in this study. The follow-up period was 7–50 months (mean, 23.4 months). There was a clear correlation between the severity of damage to the joint structures (the menisci and articular cartilage) and the level of return to sports. The most common reason for not being able to return to the original level of sports activity was “pain”. Thus, it was concluded that irreversible secondary damage to joint structures was an important factor hindering return to sports after ACL reconstruction. This study showed that the incidence of meniscal injury and cartilage damage increased with the passage of time after ACL injury, and that, once meniscal injury develops, the incidence of cartilage damage increases. Since sports activity is a factor that accelerates or promotes processes that give rise to this meniscal injury and cartilage damage, it was concluded that it is vital to perform ACL reconstruction before irreversible secondary damage to joint structures occurs in athletes with ACL injuries who hope to continue their sports activities.     

同种异体半关节移植治疗股骨远端肿瘤

目的 对大段异体骨移植用于骨肿瘤保肢治疗及其相关问题进行分析讨论。方法采用大段异体骨修复骨肿瘤瘤段切除后骨缺损5例，术后X线及同位素骨扫描评定骨愈合，并评估其功能恢复情况。结果手术后3—6个月在X线片显示牢固的生物固定（坚强的外骨痂或已骨性连接）、^99mTc—MDP骨扫描图像显示异体骨早期代谢活跃，2年后逐渐恢复正常。结论 同种异体骨半关节移植治疗股骨远端肿瘤术后观察移植骨与自体骨愈合，关节功能重建方面到达良好表现。     

降钙素在体内体外实验中对兔关节炎关节软骨退变及软骨下骨骨代谢的影响

[目的]研究降钙素(calcitonin, CT)对骨性关节炎关节软骨退变和软骨下骨骨代谢的影响.[方法]30只3个月龄雌性日本大耳白兔随机分为三组,其中两组行右膝关节前交叉韧带切断术(anterior cruciate ligament transaction,ACLT),分为ACLT+CT组和ACLT+NS组,第3组为Sham组.ACLT+CT给予每日1次皮下注射降钙素5 IU/(kg·d),持续8周,ACLT+NS组给予同样剂量生理盐水.术后8周后处死所有动物.取股骨髁制成切片行MMP-13和Ⅱ型胶原免疫组化染色.取胫骨近端制成硬组织切片行骨形态计量学检测.体外实验中,取兔膝关节软骨,经消化、培养,将第3代软骨细胞分三组:向IL-1β组加入人重组IL-1β(10 ng/ml). IL-1β+CT组加入人重组IL-1β (10 ng/ml)2 d后,再向培养液中加入CT(50 ng/ml).正常组不加任何诱导剂和干扰剂培养.然后行MMP-13、Ⅱ型胶原免疫组化检测和Realtime RT-PCR法检测.[结果]Sham组和ACLT+CT组软骨下骨骨小梁相对体积和厚度等均显著高于ACLT+NS组.Sham组和ACLT+CT组的Ⅱ型胶原的光密度值均显著高于ACLT+NS组,而MMP-13的光密度值显著低于ACLT+NS组(P<0.05).正常组和IL-1β+CT组的Ⅱ型胶原光密度值均显著高于IL-1β组而MMP-13的光密度值都显著低于IL-1β组(P<0.05).在正常组和IL-1β+CT组中Ⅱ型胶原的mRNA含量均显著高于IL-1β组而MMP-13的mRNA含量均显著低于IL-1β组(P<0.05).[结论]降钙素5 IU/(kg·d)皮下注射能够增加ACLT兔膝关节软骨Ⅱ型胶原的分泌和抑制MMP-13的表达,并可能通过调节软骨下骨的骨代谢和微结构来保护关节软骨; CT(50 ng/ml)能增加体外培养的含有IL-1β(10 ng/ml)的软骨细胞中Ⅱ型胶原的含量和抑制MMP-13分泌.     

在体阻断软骨下营养对关节软骨影响的实验研究

背景：关节软骨无血管分布,其营养来自关节液和软骨下骨,哪条营养通路对关节软骨更为重要是学者们争论的焦点。目的：研究软骨下营养对关节软骨的影响,并探讨软骨下营养与骨关节炎的关系。方法：45只5个月龄雄性新西兰大白兔,建立股骨滑车骨软骨缺损的动物模型,并随机分为3组：自体骨软骨块移植组（Control组,n=15）;假手术组（Sham组,n=15）,用环钻在股骨滑车钻取骨软骨块,将其置入管状PVC内,原位回植;阻断软骨下营养组（DNBM组,n=15）,取出骨软骨后,将其置入帽状PVC内,原位回植。术后4周、8周、12周,每组5只（10膝）,取出膝关节进行大体评分、组织学评分、软骨厚度测量、凋亡染色（TUNEL染色）。结果：与Control组相比,大体评分结果提示,DNBM组软骨无明显退变;组织学评分结果提示,术后12周时DNBM组软骨明显退变（P〈0.005）;软骨厚度测量结果提示,术后8周、12周时DNBM组软骨厚度明显变小（P=0.00）;TUNEL染色结果提示,术后8周、12周时DNBM组关节软骨细胞凋亡明显增加（P〈0.01）。结论：软骨下营养是软骨的重要营养来源,失去软骨下营养,软骨会逐渐发生退变。     

Metabolic and biochemical status of articular cartilage following cryopreservation and transplantation: a rabbit model.

To determine the fate of transplanted cryopreserved articular cartilage, an animal model employing the proximal humerus in the rabbit has been developed. Previous studies have been hindered by problems of postoperative joint instability, secondary injury due to immobilization, and paucity of cartilage for analysis. This experiment demonstrates the survival and function of transplanted cartilage by quantitative assessment of metabolic and biochemical parameters. Forty-five New Zealand white rabbits underwent transplantation of the right proximal humerus. In 29 animals, the proximal half of the humerus was resected and replaced by a cryopreserved osteoarticular allograft. Autograft procedures were carried out in the remaining animals. Following sacrifice at 3, 6, 9, and 12 months postoperatively, articular cartilage was analyzed for gross appearance, collagen synthesis, proteoglycan synthesis, and water, hydroxyproline, hexosamine, and hexuronic acid contents. The results indicate that the cryopreserved osteoarticular allografts retained their metabolic and biochemical integrity and behaved as viable and biologically functional units 1 year postoperatively.     

Effects of varying intensities of laser energy on articular cartilage: a preliminary study

The effects of laser energy on articular cartilage were studied utilizing the neodymium YAG laser. Partial-thickness cartilage defects were surgically attempted in the femoral condyles of knee joints in guinea pigs. The defects were exposed to laser energy of varying intensities [group I, 25 J (5 W X 5 sec); group II, 75 J (15 W X 5 sec); group III, 125 J (25 W X 5 sec)]. A fourth group was studied, in which the defect was not lased. Animals were killed at weekly intervals from 1 to 6 weeks and the knee joints were subjected to histological analysis. At 5 weeks, the knees exposed to 25 and 75 J demonstrated a reparative process with chondral proliferation. The knees exposed to 125 J demonstrated fibrotic tissue and tissue necrosis that resulted in fibrosis. In the knees not exposed to laser energy, numerous foci of granulation tissue were present at all stages with the end point of healing being one of fibrosis with disorganized patchy cartilage islands.     

The effect of cryopreservation on the biomechanical behavior of bovine articular cartilage

The short-term effect of cryopreservation on specific mechanical behaviors of bovine articular cartilage has been investigated. A flat-ended nonporous indentor was used in a nondestructive, repetitive, axisymmetric unconstrained testing system. Cyclical indentation from a fixed position to a fixed load was applied until a steady-state load-deformation relationship (limit cycle) was achieved. Indentation behaviors measured from the limit cycles of each articular cartilage specimen before and after treatment were compared. Testing was done in vitro using fresh, mature bovine radiocarpal joints. Twenty pairs of cartilage-subchondral bone cores from anatomically similar sites on contralateral joints were separated into three groups; thickness controls, dimethylsulfoxide (DMSO) controls, and cryopreserved experimental samples. Thickness controls and DMSO controls were used to examine the isolated effects of the thickness measurement and DMSO incubation techniques on articular cartilage indentation characteristics. Experimental samples were cryopreserved using DMSO, their thicknesses similarly measured and indentation behaviors examined. Following testing, histological and histochemical assessment of the specimens confirmed the nondestructive nature of the tests. Intra- and intergroup comparisons of controls and experimentals revealed no statistical differences in the mechanical behaviors measured from the limit cycle or in cartilage thickness. These results indicate that the cryopreservation protocol used did not have an effect that we could measure on these specific mechanical behaviors of articular cartilage.     

The repair of experimentally produced defects in rabbit articular cartilage by autologous chondrocyte transplantation

Using the knee joints of New Zealand White rabbits, a baseline study was made to determine the intrinsic capability of cartilage for healing defects that do not fracture the subchondral plate. A second experiment examined the effect of autologous chondrocytes grown in vitro on the healing rate of these defects. To determine whether any of the reconstituted cartilage resulted from the chondrocyte graft, a third experiment was conducted involving grafts with chondrocytes that had been labeled prior to grafting with a nuclear tracer. Results were evaluated using both qualitative and quantitative light microscopy. Macroscopic results from grafted specimens displayed a marked decrease in synovitis and other degenerative changes. In defects that had received transplants, a significant amount of cartilage was reconstituted (82%) compared to ungrafted controls (18%). Autoradiography on reconstituted cartilage showed that there were labeled cells incorporated into the repair matrix.