Repair of cartilage defects. Technical aspects

Efficacious treatment of chondral and osteochondral defects of the weight bearing surfaces represents a real challenge for the orthopaedic surgeon. Treatment options for full thickness cartilage defects are discussed in this paper. Poor biomechanical characteristics of the reparative fibrocartilage promoted by "traditional resurfacing techniques" provide only moderate clinical outcome in the treatment of such lesions. During the last decade several new efforts have been expressed to provide a hyaline or hyaline-like gliding surface for a full thickness defected area on the weight bearing surface. Among several surgical procedures, autologous osteochondral transplantation methods, including osteochondral mosaicplasty, chondrocyte transplantation, periosteal and perichondrial resurfacement and allograft transplantation are the favoured "new methods". Experimental background, operative techniques and clinical results of these new procedures are detailed in this overview. According to the early and medium term experiences of these methods it seems that a hyaline or hyaline-like resurfacement of the defected area can provide a more durable gliding surface and a better clinical outcome than the so called "traditional resurfacing techniques". Autologous osteochondral mosaicplasty--as an easy, one-step procedure, providing a relatively quick rehabilitation--can be an alternative in the treatment of small and medium sized lesions. Excellent clinical outcome, low costs of the treatment and short rehabilitation time represent the main advantages of this method. Autologous chondrocyte transplantation seems to be a promising option in the treatment of larger full thickness defects but requires relatively expensive two-step procedure and longer rehabilitation period. Both of the above mentioned techniques have femoral, tibial, patellofemoral and talar applications as well. According to the present recommendations transplantation of osteochondral allografts can be indicated at massive osteochondral lesions. There are less experiences with the clinical use of periosteal and perichondrial resurfacing techniques and biomaterials. Beside the promising early and medium term results of these methods the authors express that a successful treatment of the full-thickness cartilage damages of the weight bearing surfaces depends not only the way of the cartilage repair but on the treatment of the underlying cause as well. According to this statement for an effective treatment of full thickness defects on the weight bearing surfaces requires careful patient selection, complex operative plan and well organized treatment course.     

Repair of articular cartilage defects with cultured chondrocytes on polysulphonic membrane: experimental studies in rabbits

INTRODUCTION: Autologous osteochondral transplantation is one method that can be used to create hyaline or hyaline-like repair in a defect area. The purpose of the present study was to repair full-thickness articular cartilage defects in 9 rabbit knee joints with autologous cultured chondrocytes. METHODS: An articular cartilage defect was created on the patellar groove of the femur. The defect was filled with chondrocytes cultured in vitro and placed into the knee on a polysulphonic membrane. At 8 weeks after the operation, the reparative tissue was analyzed macroscopically and histologically. RESULTS: At 8 weeks after the operation, the surfaces of the reparative tissue were smooth, and the defects were filled with mature hyaline cartilage in 5 cases. In 2 cases, the reparative hyaline cartilage was immature and there was worse integration of grafted tissue into the adjacent normal cartilage. In 2 cases, the surface of the grafted area was irregular, and the reparative tissue was disintegrated and incompletely differentiated. CONCLUSION: The results suggest that transplantation of autologous chondrocytes cultured in vitro and placed into the knee on polysulphonic membrane is effective in repairing an articular cartilage defect.     

Articular cartilage repair using tissue engineering technique--novel approach with minimally invasive procedure

Articular cartilage has very limited potential to spontaneously heal, because it lacks vessels and is isolated from systemic regulation. Although there have been many attempts to treat articular cartilage defects, such as drilling, microfracture techniques, soft tissue grafts or osteochondral grafts, no treatment has managed to repair the defects with long-lasting hyaline cartilage. Recently, a regenerative medicine using a tissue engineering technique for cartilage repair has been given much attention in the orthopedic field. In 1994, Brittberg et al. introduced a new cell technology in which chondrocytes expanded in monolayer culture were transplanted into the cartilage defect of the knee. As a second generation of chondrocyte transplantation, since 1996 we have been performing transplantation of tissue-engineered cartilage made ex vivo for the treatment of osteochondral defects of the joints. This signifies a concept shift from cell transplantation to tissue transplantation made ex vivo using tissue engineering techniques. We have reported good clinical results with this surgical treatment. However, extensive basic research is vital to achieve better clinical results with this tissue engineering technique. This article describes our recent research using a minimally invasive tissue engineering technique to promote cartilage regeneration.     

Autologous osteochondral grafting in the knee: indication,results, and reflections

The use of multiple autologous osteochondral plugs (mosaicplasty) for repair of articular cartilage defects is a well-accepted technique. Since 1995, the authors have used mosaicplasty to treat more than 110 patients with cartilage defects of the knee, hip, and ankle. The first 52 consecutive patients who had mosaicplasty of the knee and have an average followup of 37 months (range, 24-56 months) were examined. Indications for surgical treatment were osteochondritis dissecans, acute trauma, and posttraumatic lesions of the femorotibial joint, femoropatellar maltracking with recurrent episodes of patella dislocations, and distinct femoropatellar arthrosis. Preoperatively, cartilage defects were classified as International Cartilage Repair Society Grade III lesions in 23 patients and Grade IV lesions in 29 patients. Two years after surgery, an increased level of knee function was found in 86% of the patients. At the latest followup, improved knee function was observed in 92% of the patients. In four patients, reoperation was necessary because of graft failure. Complications and reoperation rate were related to large surface lesions. Autologous osteochondral transplantation is a valid option for the treatment of full-thickness osteochondral defects. However, the method is limited by the defect size and the number of plugs to be taken at the donor site.     

Osteochondrose des Talus

Background

Osteochondral lesion (OCL) is a common lesion that influences the quality of life of patients. In addition due to incongruence of the joint surface in advanced stages as well as the lack of regenerative capacity of hyaline cartilage, osteochondral lesions can lead to an early onset of osteoarthritis; therefore, surgical treatment is often necessary and conservative treatment options are only promising in the early stages of OCL.

Therapy

Autologous osteochondral transplantation is the only technique that resurfaces defects with viable hyaline vital cartilage. Other operative techniques, such as bone marrow stimulating techniques or autologous chondrocyte transplantation generate fibrocartilage with less biomechanical properties when compared to hyaline cartilage. Transplant morbidity and the body mass index of the patient are important factors which must also be taken into consideration.     

The utilisation of osteochondral autologous grafts in the treatment of articular cartilage lesions

It is well known that the capacity of articular cartilage for repair is limited. There have been many attempts to address this problem. However, treatment options are limited and the long-term outcome is uncertain. This article will focus on the osteochondral autograft transplantation (OAT), which is currently the only surgical cartilage repair technique that provides and retains proper hyaline articular cartilage. Osteochondral autograft transplants have been associated with a good rate of success, but further long-term follow-up and biomechanical evaluation are essential. Limitations: size and depth of osteochondral defects, availability of donor autologous grafts, potential for damaging donor sites, the dead spaces between circular grafts and integration of donor and recipient hyaline cartilage.     

The osteochondral dilemma: review of current management and future trends

The management of articular cartilage defects remains challenging and controversial. Hyaline cartilage has limited capacity for self‐repair and post‐injury cartilage is predominantly replaced by fibrocartilage through healing from the subchondral bone. Fibrocartilage lacks the key properties that characterize hyaline cartilage such as capacity for compression, hydrodynamic permeability and smoothness of the articular surface. Many reports relate compromised function associated with repaired cartilage and loss of function of the articular surface. Novel methods have been proposed with the key aim to regenerate hyaline cartilage for repair of osteochondral defects. Over the past decade, with many exciting developments in tissue engineering and regenerative cell‐based technologies, we are now able to consider new combinatorial approaches to overcome the problems associated with osteochondral injuries and damage. In this review, the currently accepted surgical approaches are reviewed and considered; debridement, marrow stimulation, whole tissue transplantation and cellular repair. More recent products, which employ tissue engineering approaches to enhance the traditional methods of repair, are discussed. Future trends must not only focus on recreating the composition of articular cartilage, but more importantly recapitulate the nano‐structure of articular cartilage to improve the functional strength and integration of repair tissue.     

Autologous chondrocyte transplantation in osteochondral lesions of the ankle joint

The aim of this study was to assess the repair of osteochondral defects of the ankle joint with hyaline cartilage. For this purpose we have been using a technique of autologous chondrocyte transplantation for osteochondral defects of the talus for the last two years. Until the method described in the paper, treatment methods proposed for the repair of cartilaginous defects have not been histologically effective in restoring the hyaline cartilage sheath, and in all cases the neoformation of cartilage was of a fibrocartilaginous nature with varying cellular characteristics. Clinical and histological results obtained using this surgical technique have confirmed its validity. Furthermore, neither subjective nor objective complications have been reported. Less pain and better articular function have also been observed. According to the AOFAS score, an improvement from an average score of 32/100 points pre-op. to 91/100 points at 24 months of follow up was obtained. Laboratory data have confirmed the presence of reconstructed cartilage with chondrocytes and expression of collagen II, characteristic of hyaline cartilage.     

Injuries to the Articular Cartilage

Abstract Injuries to articular cartilage are commonly encountered in orthopedic sports medicine. These lesions can lead to sport invalidity and premature osteoarthritis. The management of chondral and osteochondral lesions represents a challenge to clinicians and scientists. The aim of the therapy has to be the recurrence to former sport levels and the prevention of early osteoarthritis. Today there are different concepts of treatment. One therapy principle is the recruitment of mesenchymal stem cells. These procedures lead at best to fibrocartilaginous repair tissue that is functionally inferior to normal hyaline cartilage. Another group of procedures is the transplantation of autologous osteochondral grafts, which provide repair with a hyaline cartilage matrix and show good clinical medium-term results. But osteochondral grafts are limited and there is a potential donor-site morbidity. Finally, the transplantation of autologous chondrocytes is used. However, this kind of transplantation repairs the chondral injury only by fibrocartilaginous repair tissue, too. Therefore, new techniques for the treatment of articular cartilage injuries have to be established. The most promising field today is the combination of tissue-engineering and gene therapeutic methods for the treatment of the chondral and osteochondral lesions.     

Mosaïcplasty

Management of the patient with symptomatic full-thickness chondral or osteochondral defects of the knee presents a challenging problem for the orthopedic surgeon. The natural history of untreated lesions demonstrates progressive degenerative changes and deterioration in functional outcome scores. Medical management, osteotomies, lavage, and debridement procedures temporize symptoms and slow progression. Cartilage restoration procedures such as microfracture and cell-based therapies have shown promise, but there are concerns of the long-term durability of these procedures in the active population. Mosaicplasty allows for restoration of articular defects with hyaline cartilage, and has shown excellent durability. Articular defect should measure between 1 to 4 cm(2) in diameter and extend 10 mm into subchondral bone. Mosaicplasty can be challenging when attempted arthroscopically, and the threshold to convert to an open procedure should be low when adequate visualization is not achieved. Use of variable graft size maximizes defect fill with hyaline cartilage. Avoidance of graft prominence >1 mm and attention to the contour of the joint optimizes the recreation of articular surface. This is achieved by placing central grafts in a large defect slightly prouder to obtain a convex shape to the articular surface. With attention to the nuances of the surgical technique, mosaicplasty offers an excellent option for cartilage restoration in the young active patient.     

Osteochondritis dissecans of the talus treated by the transplantation of tissue-engineered cartilage

Management of osteochondral lesions of the joint has been difficult, because articular cartilage has a poor healing capacity as a result of its lack of vessels, nerve supply, and its isolation of systemic regulation. Although a lot of basic research and surgical treatments for cartilage repair have focused on osteochondral lesions in the knee joint, orthopedic surgeons have recently diverted their attention to osteochondral lesions in the ankle joint, partly because of the widespread introduction of arthroscopy in ankle surgery. There have been many attempts to treat articular cartilage defects in the ankle joint as well as in the knee joint. However, no treatment has achieved efficient healing with hyaline cartilage. Recently, tissue engineering technique for cartilage repair has been gaining much attention in the orthopedic field. In this study, we reported on a patient with osteochondritis dissecans of the talar dome, successfully treated by transplantation of tissue-engineered cartilage made ex vivo using atelocollagen gel and low tibial osteotomy.     

Articular cartilage transplantation. Current and future limitations and solutions

The ultimate goal of replacing cartilage with a bioengineered graft, autologous graft, or allograft is to replace the damaged articulating surface with tissue containing the anatomical, biomechanical, and functional properties of native articular cartilage, which will have resultant satisfactory clinical outcome. For transplanted articular cartilage to obtain the original histologic arrangement of hyaline cartilage with secure incorporation into host tissue, progressive integrated multidisciplinary research must continue. Although autologous chondrocyte transplantation of the talus is not yet FDA approved, this technique may provide the surgeons with a cutting-edge method to treat patients with nondegenerative osteochondral lesions of the talus and possibly other articulating joints of the foot.     

Management of focal chondral lesion in the knee joint

Articular cartilage does not contain vascular, nervous and lymphatic tissue and chondrocytes hardly participate in the healing or repair process of chondral tissue because of being surrounded by plenty of extracellular matrix. Therefore, the injury to articular cartilage frequently requires an operative treatment. The goal of surgical repair of articular cartilage is to regenerate nearly normal chondral tissue and prevent degenerative arthritis caused by the articular cartilage defect. Microfracture is a kind of cartilage repair procedure that makes a fibrin clot containing mesenchymal stem cells in the chondral lesion. Microfracture is a simple procedure but it has a disadvantage that the repaired tissue is fibrocartilage. Autologous chondrocyte implantation has an advantage that it implants fully differentiated chondrocytes to the lesion, which theoretically produces hyaline cartilage. Its disadvantages are that it is a two stage and a costly procedure. Osteochondral autograft transplantation is a one stage procedure and repairs the lesion with hyaline cartilage. But its limitation is the lack of donor site availability. Surgeons who understand the theoretical background, indications, surgical methods, rehabilitation, complications, and clinical course of cartilage repair procedures can achieve the goal of preventing degenerative arthritis.     

Magnetic resonance imaging of hyaline cartilage regeneration in neocartilage graft implantation

BACKGROUND: The purpose of this study was to investigate the regenerative potential of hyaline cartilage in a neocartilage graft implant with the aid of MR cartilage imaging using a rabbit model. METHODS: Surgical osteochondral defects were created in the femoral condyles of 30 mature New Zealand rabbits. The findings of neocartilage in autologous cartilage grafts packed into osteochondral defects were compared with control group of no implant to the osteochondral defect. The outcome of the implantations was correlated with histologic and MR cartilage imaging findings over a 3-month interval. RESULTS: Neocartilage grafts packed into osteochondral defects showed regeneration of hyaline cartilage at the outer layer of the implant using MR cartilage imaging. Fibrosis of fibrocartilage developed at the outer layer of the autologous cartilage graft together with an inflammatory reaction within the osteochondral defect. CONCLUSION: This animal study provides evidence of the regenerative ability of hyaline cartilage in neocartilage transplants to repair articular cartilage.     

骨形态形成蛋白复合纤维蛋白载体修复全厚关节软骨缺损的实验研究

目的：用骨形态形成蛋白（BMP）复合纤维蛋白载体修复创伤性全厚关节软骨缺损,方法：60只新西兰家兔,体重2．5－3kg,雌雄不限,随机分为5组,每侧股骨髌髁关节面低速电钻钻一直径为4mm全厚关节软骨缺损,一侧缺损填充BMP／FS,对照侧缺损填充单纯FS,单纯BMP和空白组,膝关节不做固定,允许笼中自由活动,术后2,4,8,12周空气栓塞分批处死动物,大体观,组织学切片HE染色,S－100蛋白免疫组化染色和透射电镜观察实验结果,结果：术后4周,BMP／HF填充的部分关节软骨缺损由类透明软骨修复,术后8周,实验组缺损大部分由类透明软骨修复,而对照组则由纤维软骨或纤维组织修复,术后12周,实验组修复组织主要是透明软骨或类透明软骨,修复面较平整光滑,与周围组织愈合良好,但部分修复软骨面变薄,纤维化。结论：BMP／FS复合物促进了关节软骨的早期修复,并且最终的修复组织更接受正常的关节软骨,但术后12周修复的关节软骨出现退行性改变。     

Costal osteochondral grafts for osteochondritis dissecans of the capitulum humeri

The objective of the treatment for osteochondritis dissecans of the humeral capitulum is to prevent the occurrence of osteoarthritis and to allow the patients to return to throwing activities. In repairing osteochondral defects in advanced osteochondritis dissecans of the humeral capitulum after free body removal, we have performed block-shaped costal osteochondral grafting in 18 elbows since 1997. A block-shaped graft harvested from the transitional area between the rib and its associated cartilage was implanted to the osteochondral defect. This method allows the osteochondral defect to be repaired with uniform hyaline cartilaginous articular surface without any effect to other joints. Donor site no longer causes pain at 2 or 3 days after surgery. The purpose of this study is to describe the history, indications, and the surgical techniques of costal osteochondral grafting for advanced osteochondritis dissecans of the capitulum.     

关节镜自体骨软骨移植治疗膝关节软骨损伤

目的观察自体骨软骨移植治疗膝关节软骨缺损的效果。方法对7例膝关节股骨髁负重部位软骨损伤患者行膝关节镜清理术。摘除关节腔游离软骨碎块2例，半月板部分切除3例，髌上滑膜内侧皱襞切除3例。在股骨内侧髁部取自体骨软骨柱3～5枚，移植到股骨内侧髁软骨损伤部位。结果7例患者手术后伤口Ⅰ期愈合。随访期内6例患者疼痛症状消失。关节肿胀、假性交锁症状均消失。X线片显示移植骨软骨位置良好。结论自体软骨移植能缓解关节软骨损伤后出现疼痛、交锁症状，修复后的软骨为透明软骨。     

Mosaicplasty: long-term follow-up

The successful treatment of chondral and osteochondral defects of the weightbearing surfaces is a challenge for orthopaedic surgeons. Autologous osteochondral transplantation is one method that can be used to create a hyaline or hyaline-like repair in the defect area. Ten years of clinical experience with autologous osteochondral mosaicplasty are described. Clinical scores, imaging techniques, arthroscopy, histological examination of biopsy samples, and cartilage stiffness measurements were used to evaluate the clinical outcomes and quality of the transplanted cartilage in a total of 831 patients who underwent mosaicplasty. According to our investigations, good-to-excellent results were achieved in 92% of the patients treated with femoral condylar implantations, in 87% of those treated with tibial resurfacing, in 79% of those treated with patellar and/or trochlear mosaicplasties, and in 94% of those treated with talarprocedures. Long-term donor-site disturbances, which were assessed using the Bandi score, showed that patients had 3% morbidity after mosaicplasty. Sixty-nine of 83 patients who were followed arthroscopically showed congruent gliding surfaces, histological evidence of the survival of the transplanted hyaline cartilage, and fibrocartilage filling of the donor sites. Four deep infections and 36 painful postoperative hemarthroses were experienced as complications arising from the surgical procedures. On the basis of both these promising results and also those of other similar studies, autologous osteochondral mosaicplasty would appears to be an alternative for the treatment of small and medium-sized focal chondral and osteochondral defects of the weightbearing surfaces of the knee and other weightbearing synovial joints.     

Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC)

Degenerative and traumatic articular cartilage defects are common, difficult to treat, and progressive lesions that cause significant morbidity in the general population. There have been multiple approaches to treat such lesions, including arthroscopic debridement, microfracture, multiple drilling, osteochondral transplantation and autologous chondrocyte implantation (ACI) that are currently being used in clinical practice. Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC) is a single-staged arthroscopic procedure. This method combines a modified microfracture technique with the application of a bone marrow aspirate concentrate (BMAC), hyaluronic acid and fibrin gel to treat articular cartilage defects. We reviewed the current literatures and surgical techniques for mesenchymal cell induced chondrogenesis.     

Osteochondral allograft transplantation in the knee

Fresh osteochondral allograft (OCA) transplantation has over a 100-year clinical history. Many clinical and basic scientific studies have been performed with the result that allografting is now a part of the "cartilage repair paradigm" for the treatment of chondral or osteochondral lesions. In the knee joint, allografting has also been successfully used in complex joint reconstruction for the treatment of osteonecrosis, fracture malunion, and selected cases of osteoarthritis. Unlike many other cartilage repair techniques, OCA have the ability to restore mature, hyaline articular cartilage to the affected area. By virtue of their composite structure (cartilage and bone), allografts also can restore diseased or damaged bone often present in large or complex lesions. Nevertheless, OCA present unique and important difficulties in their clinical application, such as allograft tissue availability, safety issues, and immunologic response to the graft. Ongoing investigations continue to clarify the indications, surgical techniques, and clinical outcomes of fresh OCA.