The temporal sequence of spontaneous repair of osteochondral defects in the knees of rabbits is dependent on the geometry of the defect

Damage to articular cartilage is a common injury, for which there is no effective treatment. Our aims were to investigate the temporal sequence of the repair of articular cartilage and to define a critical-size defect. Full-thickness defects were made in adult male New Zealand white rabbits. The diameter (1 to 4 mm) of the defects was varied in order to determine the effect that the size and depth of the defect had on its healing. The defects were made in the femoral groove of the knee with one defect per knee and eight knees per group. The tissues were fixed in formalin at days 3, 7, 14, 21, 28, 42, 84 and 126 after operation and the sections stained with Toluidine Blue. These were then examined and evaluated for several parameters including the degree of metachromasia and the amount of subchondral bone which had reformed in the defect. The defects had a characteristic pattern of healing which differed at different days and for different sizes of defect. Specifically, the defects of 1 mm first peaked in terms of metachromasia at day 21, those of 2 mm at day 28, followed by defects of 3 mm and 4 mm. The healing of the subchondral bone was slowest in defects of 1 mm.     

Effective repair of a fresh osteochondral defect in the rabbit knee joint by articulated joint distraction following subchondral drilling.

PURPOSE: Joint distraction has been used to treat osteoarthritis and was found to delay the need for arthrodesis or joint replacement. However, there has been little basic research on articulated joint distraction for the repair of osteochondral defects. We investigated the effects of joint distraction with motion after drilling on a fresh osteochondral defect in the weight bearing area of the rabbit knee joint. METHODS: A full thickness osteochondral defect was created in the weight bearing area of both medial femoral condyles of an adult Japanese white rabbit. After drilling of the defect, the experimental knee joint was distracted for 1.5 mm using a pair of external fixators to decrease compression force. The contralateral knee joint was used as a control with no apparatus. Gross findings and histological evaluation were assessed to study morphology of the repaired cartilage. RESULTS: A partial repair with cartilage-like tissue was observed in the joints of the experimental group at 4 weeks. While cartilage-like tissue stained with Safranin O was found in the experimental group at 8 and 12 weeks, destructive changes were observed in the control joints. Morphological changes were evaluated using the histological grading scale [Wakitani S, Goto T, Pineda SJ, et al. Mesenchymal cell-based repair of large, full-thickness defect of articular cartilage. J Bone Joint Surg Am 1994;76(4):579-92]. There was no significant difference between experimental and control groups at 4 weeks (mean 11.2 and 13.8 points, respectively). However, the mean scores of the experimental groups at 8 and 12 weeks (mean 6.8 and 7.5, respectively) were significantly better than those of the control groups at the same time points (mean 14 points each). Between the experimental groups, the scores at 8 and 12 weeks were both significantly better than those at 4 weeks. CONCLUSION: A combination of subchondral drilling, joint motion and distraction by an articulated external fixator promoted repair of a fresh osteochondral defect in the weight bearing area. Although distraction for 4 weeks was not a long enough period to repair the defect, distraction for 8 and 12 weeks resulted in a good outcome.     

富血小板血浆复合再生支架修复兔骨软骨缺损

[目的]观察富血小板血浆(PRP)复合支架修复新西兰兔膝关节骨软骨缺损的效果。[方法]抽取成年新西兰兔静脉血,两次离心后获取PRP。采用10%Ca Cl2激活其中的血小板,ELISA法检测激活前后TGF-β的浓度。成年新西兰兔在股骨内髁软骨面上制备骨软骨缺损模型。按缺损置入处理,将动物分为三组,分别是空白对照组、单纯支架组和PRP-支架组。术后6、12周取材,进行大体观察和国际软骨修复协会(ICRS)大体形态评分,此外,采用HE染色和番红O-固绿染色进行组织观察评估。[结果]PRP激活后TGF-β的浓度显著高于未激活时(P0.05)。术后6周,单纯支架组与PRP-支架组的ICRS评分显著高于空白对照组(P0.05);术后12周,单纯支架组与PRP-支架组的ICRS评分仍显著高于空白对照组(P0.05),且PRP-支架组的评分显著高于单纯支架组(P0.05)。HE染色与番红O-固绿染色表明,单纯支架组和PRP-支架组的修复明显优于空白对照组,且PRP-支架组的修复较单纯支架组更优。[结论]单纯支架能够促进兔膝关节骨软骨缺损的修复,但修复效果有限。激活后的PRP能够明显提高支架的作用,PRP-支架是此动物实验中最佳的骨软骨修复方式。     

Allogeneic deep frozen meniscal graft for repair of osteochondral defects in the knee joint

Osteochondral defects in the knee joints of five patients caused by trauma or osteochondritis dissecans were repaired using deep-frozen allogeneic meniscal grafts. Three patients were male and two were female, with a mean age of 26.4 years. The mean follow-up period was 31 months. Postoperative magnetic resonance imaging (MRI) at all periods clearly showed a smooth and congruous articular surface, although the signal intensity of the grafted meniscus was not the same as that of the articular cartilage. Second-look arthroscopy performed approximately 1 year after surgery demonstrated that the grafted meniscus was well bonded to the grafted site, not sunken; there was no gap between the grafted meniscus and the surrounding articular cartilage, indicating that the grafted meniscus functions as a part of the articular surface. Histologic examination revealed that host cells had infiltrated into the meniscus and that cells surrounded by thin collagen fibrils were morphologically similar to fibrochondrocytes. Thus, the acellular grafted meniscus regenerated as meniscal tissue and formed an articular surface, although hyalinization did not occur. Our results suggest that deep-frozen allogeneic meniscal grafting is a useful method to repair osteochondral defects in the knee joint.     

Regeneration of articular cartilage--evaluation of osteochondral defect repair in the rabbit using multiphasic implants

OBJECTIVE: To investigate whether two different multiphasic implants could initiate and sustain repair of osteochondral defects in rabbits. The implants address the malleable properties of cartilage while also addressing the rigid characteristics of subchondral bone. DESIGN: The bone region of both devices consisted of D, D-L, L-polylactic acid invested with hyaluronan (HY). The cartilage region of the first device was a polyelectrolytic complex (PEC) hydrogel of HY and chitosan. In the second device the cartilage region consisted of type I collagen scaffold. Eighteen rabbits were implanted bilaterally with a device, or underwent defect creation with no implant. At 24 weeks, regenerated tissues were evaluated grossly, histologically and via immunostaining for type II collagen. RESULTS: PEC devices induced a significantly better repair than untreated shams. Collagen devices resulted in a quality of repair close to that of the PEC group, although its mean repair score (19.0+/-4.2) did not differ significantly from that of the PEC group (20.4+/-3.7) or the shams (16.5+/-6.3). The percentage of hyaline-appearing cartilage in the repair was highest with collagen implants, while the degree of bonding of repair to the host, structural integrity of the neocartilage, and reconstitution of the subchondral bone was greatest with PEC devices. Cartilage in both device-treated sites stained positive for type II collagen and GAG. CONCLUSIONS: Both implants are capable of maintaining hyaline-appearing tissue at 24 weeks. The physicochemical region between the cartilage and bone compartments makes these devices well suited for delivery of different growth factors or drugs in each compartment, or different doses of the same factor. It also renders these devices excellent vehicles for chondrocyte or stem cell transplantation.     

Combination therapy with intra‐articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit

The present study investigated intra‐articular injection of bone‐marrow‐derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight‐bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra‐articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra‐articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1466–1473, 2015.     

静电纺纳米聚乳酸己内酮共聚物导管修复周围神经缺损的实验研究

目的 探讨应用同轴静电纺丝技术制备的聚乳酸己内酮共聚物[Poly(1-lactide-co-epsilon-caprolactone),P(LLA-CL)]导管,移植修复大鼠周围神经缺损的效果.方法 选取健康SD大鼠54只,随机分成3组,每组18只.先造成坐骨神经1.5cm缺损段,然后分别采用P(LLA-CL)导管桥接(A组)、硅胶管桥接(B组)、自体神经逆行原位移植(C组).分别在术后4、8、12周对大鼠进行大体观察、坐骨神经功能指数检查、神经电生理检查、肌肉湿重、再生有髓神经纤维计数、电镜观察,评价各组神经再生.结果 术后4周时A组再生神经已部分生长到导管的中部;8周时再生神经已通过神经导管,但再生的神经纤细;12周时再生神经粘连较轻,直径较粗.A组的坐骨神经功能指数、神经电生理、肌肉湿重和组织学观察等各项指标均略差于C组,但明显优于B组.结论 纳米聚乳酸己内酮神经导管具有促进神经轴突再生的作用,有望成为自体神经移植的替代材料应用于周围神经缺损的修复.     

Treatment of a traumatic osteochondral defect in the thumb carpometacarpal joint with a periosteal autograft

We report a case in which an autogenous periosteal autograft was used to resurface a large osteochondral defect in the thumb carpometacarpal joint of a young woman. Good results were found at 4-year follow-up examination.     

Devices for use as an artificial articular surface in joint prostheses or in the repair of osteochondral defects

The covering of ultra high molecular weight polyethylene (UHMWPE) and calcium hydroxyapatite (HA)/tricalcium phosphate (TCP) porous solid substrate with polyHEMA hydrogel has been studied aiming at the development of devices to be used as artificial articular surfaces in joint prosthesis or osteochondral repair grafts. Commercial porous UHMWPE was used. Ceramic porous substrate was prepared by load compaction of an HA and TCP powder mixture obtained by aqueous precipitation technique. Two different compaction loads and grain size distribution was used. Polymer particles were added to the powder mixture in order to increase the substrate porosity after the sintering process. The porous substrate was covered with polyHEMA hydrogel by in situ polymerization. Morphological analysis (SEM) showed that a hydrogel layer formed in the porous solid top surface was fixed to the substrate by mechanical interlocking because the porous surface was filled by the hydrogel. After hydrogel covering, the resultant devices showed a decrease in the compressive elastic modulus that was influenced by the porous substrate material.     

Maintenance of trabecular structure and bone volume by vitamin K(2) in mature rats with long-term tail suspension

 Bone volume loss is one of the major health problems during long-term spaceflight. We examined the effects of vitamin K₂ on bone abnormalities in tail-suspended mature male Sprague-Dawley rats (13 weeks old). In this model, increased bone resorption and sustained suppression of bone formation resulted in progressive bone loss in 4 weeks, which simulates bone changes in humans during spaceflight. A significant decrease in bone mineral density (BMD), as well as a decreased mineral apposition rate (MAR), increased number of osteoclasts per bone perimeter (N.Oc/B.Pm), and increased osteoclast surface per bone surface (Oc.S/BS) in the suspended group was effectively prevented by vitamin K₂, given orally (menatetrenone, 22 mg/kg body weight). Microfocus computed tomography (CT) and node-strut analyses revealed that the volume and structure of trabecular bone were maintained near normal by the vitamin K₂ treatment. A recent report has suggested the abnormal metabolism or action of vitamin K in a microgravity environment, and our data therefore suggest that vitamin K₂ may be useful for the prevention of bone loss and for the maintenance of normal trabecular structure during spaceflight. Received: August 31, 2001 / Accepted: December 28, 2001     

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model

Background

Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects.

No effect of subperiosteal growth factor application on periosteal neo-chondrogenesis in osteoperiosteal bone grafts for osteochondral defect repair

Purpose

The purpose of this study was to examine the effect of subperiosteal injection of chondroinductive growth factors on the histological and biomechanical outcome of autologous osteoperiosteal grafts.

Methods

Thirty six standardised osteochondral defects were created in the trochlear groove of 18 Göttinger Minipigs and evaluated after six, 12 and 52 weeks. Defects were treated with press-fit implantation of autologous osteoperiosteal cylindrical block-grafts with or without subperiosteal injection of a chondroinductive growth factor mixture (GFM).

Results

Histomorphological analysis showed complete osseointegration of all grafts from six weeks. The periosteum remained in place in 35 of 36 cases. Fibrocartilagineous repair tissue formation occurred at the cambium layer with a maximum at 12 weeks in both groups. Histomorphological grading and biomechanical testing showed highest values at 12 weeks, with signs of tissue degradation at one year. There was no significant difference between both groups.

Conclusion

Transplantation of autologous osteoperiosteal grafts is an effective method to restore subchondral bone defects, but not the overlying cartilage as the repair tissue deteriorates in the long term. Subperiosteal growth factors injection did not stimulate tissue differentiation on a biomechanical and histomorphological level.     

Techniques of chondral and osteochondral repair in the knee

Summary Spontaneous repair of chondral lesions is incomplete and of poor quality. Currently, the repair of cartilage with loss of substance can only be envisaged if it is located in a weightbearing zone in young subjects with a well aligned and stable knee. Four techniques are currently used and satisfying: microfractures, osteochondral grafts, and grafts of chondrocytes. Fresh allografts are also reported, though they are difficult to employ in Europe.     

Techniques for cartilage repair in chondral and osteochondral defects of the knee

Many techniques are currently used in an attempt to regenerate cartilage surfaces in the presence of a chondral or osteochondral defect. Clinical results have been mixed and no single treatment has emerged as being superior. This article reviews the techniques previously and currently being used and evidence to support their use.     

非对称性O-Z旋转皮瓣修复指(趾)部圆形缺损

目的 探讨非对称性O-Z旋转皮瓣修复指(趾)部圆形缺损的手术方式和临床效果.方法 采用非对称性O-Z旋转皮瓣修复33例手指(足趾)圆形缺损(面积0.5 cm×0.5 cm～1.5 cm×1.5 cm)患者.结果 33例均获随访,时间3～12个月.31例皮瓣完全成活,2例发生皮瓣边缘坏死,经加强换药后愈合.皮瓣质地、外观、功能、感觉恢复良好.根据中华医学会手外科学会上肢部分功能评定试用标准评定:皮瓣感觉31例恢复至S4,2例恢复至S3+.结论 非对称性O-Z旋转皮瓣修复手指(足趾)圆形缺损具有操作简单、创伤小、经济实用、利于指(趾)功能及外形恢复等优点,临床效果良好.     

慢速梯度降温冷冻保存同种异体骨软骨移植治疗膝关节全层软骨缺损(附三例报告)

目的总结冷冻保存同种异体骨软骨移植物治疗3例膝关节全层骨软骨缺损的手术方法及疗效。方法应用梯度降温冷冻保存的6枚同种异体骨软骨移植物治疗3例膝关节全层骨软骨缺损,2例在关节镜下同种异体骨软骨移植,1例行关节切开移植。膝关节股骨髁关节软骨全层缺损平均面积2.16 cm2。所有患者在手术后第1个月、第3个月时进行膝关节MRI检查,了解移植物与周围骨软骨组织的愈合情况。并于门诊复查时进行Brittberg-Peterson膝关节功能评分,了解功能恢复情况。结果随访4～6个月,平均4.7个月。所有患者术后疼痛消失;无排异反应发生。术后3个月时,MRI检查示术后移植物与宿主软骨下骨整合良好,移植软骨组织结构与内部信号良好。Brittberg-Peterson评分术后6个月比手术前明显降低。结论经梯度降温冷冻保存的同种异体骨软骨移植治疗膝关节软骨缺损早期效果满意。     

The detached osteochondral fragment as a source of cells for autologous chondrocyte implantation (ACI) in the ankle joint

OBJECTIVE: Autologous chondrocyte implantation (ACI) has been successfully used for the treatment of osteochondral lesions of the talus. One of the main problems of this surgical strategy is related to the harvesting of the cartilage slice from a healthy knee. The aim of this study was to examine the capacity of chondrocytes harvested from a detached osteochondral fragment to proliferate and to serve as a source of viable cells for ACI in the repair of ankle cartilage defects. METHODS: Detached osteochondral fragments harvested from the ankle joint of 20 patients with osteochondral lesions of the talus served as the source of human articular cartilage specimens. All of the osteochondral lesions were chronic and of traumatic origin. In all cases, the fragments were utilized to evaluate the viability and proliferation of the cells, the histological appearance of the cartilage tissue and the expression of specific cartilage markers by real-time polymerase chain reaction (PCR). In the 16 patients scheduled for ACI, the expanded chondrocytes were used for chondrocyte implantation. In the other 4 patients, with lesion size <1.5cm(2), microfractures were created during the initial arthroscopic step. As a control group, 7 patients with comparable osteochondral lesions underwent the same surgery, but received chondrocytes harvested from the ipsilateral knee. RESULTS: According to the American Orthopaedic Foot and Ankle Scoring (AOFAS) system, patients in the experimental group had a preoperative score of 54.2+/-16 points and a postoperative one of 89+/-9.6 points after a minimum follow-up time of 12 months (P<0.0005). The control group of patients had a preoperative score of 54.6+/-11.7 points and a postoperative one of 90.2+/-9.7 points at a minimum follow-up time of 12 months (P<0.0005). The clinical results of the two groups did not differ significantly from each other. Chondrocytes isolated from the detached fragments were highly viable, phenotypically stable, proliferated in culture and redifferentiated when grown within the three-dimensional scaffold used for ACI. The morphological and molecular characteristics of the cartilage samples obtained from the detached osteochondral fragments were similar to those of healthy hyaline articular cartilage. CONCLUSIONS: The good results achieved with this strategy indicate that cells derived from the lesioned area may be useful in the treatment of osteochondral defects of the talus.     

皮下蒂皮瓣与旋转皮瓣在颞部皮肤缺损修复中的联合应用

目的：探讨利用耳前邻近皮瓣与颞区邻近皮瓣联合应用修复颞部皮肤缺损的方法。方法：根据患者颞部皮肤肿物的大小,设计患侧耳前方皮下蒂皮瓣的切取范围并将切口线设计在耳前皱襞上。在颞部肿物外缘向耳上方延长切口线约为皮肤肿物直径的4倍,设计旋转皮瓣。2个皮瓣联合应用,修复颞部较大面积皮肤缺损。供区直接缝合。结果：共施行此类手术12例,患侧皮肤缺损修复满意,切口线相对隐蔽,面部器官形态功能均未受到影响,供区头发自然生长,瘢痕不明显。结论：利用皮下蒂皮瓣与旋转皮瓣联合修复颞部较大面积皮肤缺损,辅助切口少且切口隐蔽,同时皮瓣转移后自然平滑过渡,创面修复满意,无需植皮,瘢痕不明显。