Stadiengerechte operative Knorpeltherapie

Chondral or osteochondral lesions are typical injuries in orthopaedics and traumatology. Since there is no regeneration of damaged articular cartilage, these lesions can lead to premature osteoarthritis. Therefore, an adequate therapy for these injuries is an important goal. Nowadays, common methods in cartilage therapy are procedures for the recruitment of mesenchymal stem cells: autologous osteochondral transplantation and autologous chondrocyte transplantation. Currently, autologous osteochondral transplantation is the only procedure that allows the replacement of the defect with hyaline cartilage. However, this procedure has the problem of donor-site morbidity and limited availability of transplants. Stem cell recruiting procedures and autologous chondrocyte transplantation normally achieve a regeneration of the defect with only fibrocartilage tissue, but both can achieve good medium-term clinical results. Each of these therapeutic principles has certain major indications. In order to select an adequate therapy, the classification of chondral or osteochondral lesion is needed. From a multiplicity of classification systems, those of the ICRS are of particular clinical relevance.     

Stage oriented surgical cartilage therapy. Current situation

Chondral or osteochondral lesions are typical injuries in orthopaedics and traumatology. Since there is no regeneration of damaged articular cartilage, these lesions can lead to premature osteoarthritis. Therefore, an adequate therapy for these injuries is an important goal. Nowadays, common methods in cartilage therapy are procedures for the recruitment of mesenchymal stem cells: autologous osteochondral transplantation and autologous chondrocyte transplantation. Currently, autologous osteochondral transplantation is the only procedure that allows the replacement of the defect with hyaline cartilage. However, this procedure has the problem of donor-site morbidity and limited availability of transplants. Stem cell recruiting procedures and autologous chondrocyte transplantation normally achieve a regeneration of the defect with only fibrocartilage tissue, but both can achieve good medium-term clinical results. Each of these therapeutic principles has certain major indications. In order to select an adequate therapy, the classification of chondral or osteochondral lesion is needed. From a multiplicity of classification systems, those of the ICRS are of particular clinical relevance.     

Arthroskopische M?glichkeiten biorekonstruktiver Verfahren bei Knorpelsch?den der Schulter

Chondral or osteochondral lesions of the shoulder may lead to premature osteoarthritis of the glenohumeral joint as regeneration of damaged articular cartilage is lacking. Rising health awareness, increasingly active populations and improvements in medical techniques have increased the application of cartilage regenerative minimally invasive approaches for glenohumeral joint preservation or delayed prosthetic replacement. In contrast to the conclusive and mostly convincing mid-term results of cartilage regenerative techniques known for the knee, clinical results of innovative therapeutic approaches with glenohumeral cartilage defects are more or less absent. Current techniques include procedures for mesenchymal stem cell recruitment, such as microfracturing, (autologous) osteochondral transplantation, (matrix-associated) autologous chondrocyte transplantation and biological resurfacing, addressing focal chondral defects up to massive structural osteochondral defects. With increasing arthroscopic applicability, they evolve to important tools in the armamentarium of the shoulder surgeon. Future clinical data will determine evidence-based applicability, enabling standardized treatment selection.     

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.     

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.     

Autologous osteochondral transplantation

The surface of diarthrodial joints is covered by hyaline cartilage whose regeneration capacity is extremely limited. Conventional surgical techniques enable repair of full-thickness articular cartilage defects only by fibrous cartilage having poor mechanical properties. Recently, new techniques have been developed to provide hyaline or hyaline-like repair tissue in the treatment of full-thickness cartilage defects. Autologous osteochondral transplantation involves press-fit implantation of both bone and cartilage obtained from healthy articular surface. The principal indication for this technique is unifocal full-thickness chondral or osteochondral defects measuring 1 to 4 square centimeters. This surgical procedure can be performed openly or arthroscopically. The graft should be placed vertically and evenly to the joint surface. Although short-term and mid-term results are satisfactory, several problems have been reported including donor site morbidity, damage to cartilage, and incongruity and incorporation of the graft. Autologous osteochondral transplantation provides viable osteochondral units at a single stage and eliminates the need for culturing chondrocytes which is quite expensive. Currently, no surgical technique or medical treatment provide complete healing of articular cartilage defects. Autologous osteochondral transplantation is an important stage worthy of improvement in this respect.     

New perspectives for articular cartilage repair treatment through tissue engineering: A contemporary review

In this paper review we describe benefits and disadvantages of the established methods of cartilage regeneration that seem to have a better long-term effectiveness. We illustrated the anatomical aspect of the knee joint cartilage, the current state of cartilage tissue engineering, through mesenchymal stem cells and biomaterials, and in conclusion we provide a short overview on the rehabilitation after articular cartilage repair procedures. Adult articular cartilage has low capacity to repair itself, and thus even minor injuries may lead to progressive damage and osteoarthritic joint degeneration, resulting in significant pain and disability. Numerous efforts have been made to develop tissue-engineered grafts or patches to repair focal chondral and osteochondral defects, and to date several researchers aim to implement clinical application of cell-based therapies for cartilage repair. A literature review was conducted on PubMed, Scopus and Google Scholar using appropriate keywords, examining the current literature on the well-known tissue engineering methods for the treatment of knee osteoarthritis.     

Osteochondral autologous transplantation in various joints

A chondral/osteochondral defect involving the articular surface of a joint is still a therapeutic problem. The goal of articular cartilage repair is restoration of cartilage congruity, accomplishing full painfree range of motion and elimination of cartilage detoriation. The use of autologous grafts was first reported by Wagner 1964. Now the use of cylindrical autograft plugs was described by Bobic 1996 and Hangody 1996. Operative management and early results of osteochondral cylindrical autograft plugs in the femoral condyle, patella, elbow and talar dome are presented. The arthroscopic/open use of autologous osteochondral grafts from the knee is indicated in osteochondral lesions in diameter from 1 to 3 cm, which can not be primarily refixed and in osteonecrosis at femoral condyle, patella, elbow, talar dome as well as shoulder.     

Basic science and treatment options for articular cartilage injuries

Articular cartilage injuries can produce significant musculoskeletal morbidity for both young and active aging patient populations. The complex and highly specialized composition of normal hyaline cartilage makes treatment of focal chondral injuries a formidable challenge for the basic scientist, surgeon, and physical therapist. The current array of surgical treatment options offers palliative, reparative, and restorative treatment strategies. Palliative options include simple arthroscopic debridement. Reparative strategies utilize marrow stimulation techniques to induce formation of fibrocartilage within the chondral defect. Restorative tactics attempt to replace damaged cartilage with hyaline or hyaline-like tissue using osteochondral or chondrocyte transplantation. Furthermore, while treatment success is obviously dependent on good surgical selection and technique, the importance of sound, compliant postoperative rehabilitation cannot be understated. The purpose of this article is to review the basic science of articular cartilage, current treatment options available, and outline the clinical decision making involved when using these procedures by presenting the algorithm used at our institution for treating focal cartilage lesions.     

Large autogenous osteochondral graft for replacing knee cartilage defect

Summary Major cartilaginous defects of the femoral condyles of the knee joint, caused by chondropathy and chondral trauma can be a precursor to osteoarthritis.Particularly in cases with large defects the therapy often remains unsuccessful. Even the substitution of articular hyaline cartilage by autogenous osteochondral grafts, regarded as superior to other procedures like Pridies's drilling and abrasion arthroplasty, carries the risk of failure by necrosis of the craft and morbidity at the donor side.We present a 10-year follow-up case who had a large autogenous osteochondral graft from the non-weight bearing periphery of the patellofemoral joint that was implanted after necrosis of the medial femoral condyle following immunsuppressive chemotherapy.     

Editorial Commentary: Biological Cartilage Repair Technique—An “Effective,Accessible, and Safe” Surgical Solution for an Old Difficult Biological Problem

Achieving good long-term outcomes while treating chondral defects has always been a challenge. Several surgical techniques for regeneration of the articular cartilage have been proposed. Among them, osteochondral autograft transplantation and 2-step procedures such as autologous chondrocyte implantation have provided good results, promoting formation of new hyaline-like cartilage tissue, whereas other techniques such as microfracture result in fibrous cartilage and a less durable repair. Single-stage cell-based procedures are an attractive treatment option given the potential for cost savings and avoiding a second-stage procedure. We believe that 1-stage cartilage repair in the knee with a hyaluronic acid–based scaffold embedded with mesenchymal stem cells sourced from bone marrow aspirate concentrate has a prominent role in treating chondral defects because this is a simple technique that could improve the care of patients and be cost-effective in the near future.     

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.     

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.     

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.     

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.     

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.     

Hyaline cartilage degenerates after autologous osteochondral transplantation.

OBJECTIVES: Autologous osteochondral grafting is a well-established clinical procedure to treat focal cartilage defects in patients, although basic research on this topic remains sparse. The aim of the current study was to evaluate (1) histological changes of transplanted hyaline cartilage of osteochondral grafts and (2) the tissue that connects the transplanted cartilage with the adjacent cartilage in a sheep model. METHOD: Both knee joints of four sheep were opened surgically and osteochondral grafts were harvested and simultaneously transplanted to the contralateral femoral condyle. The animals were sacrificed after three months and the received knee joints were evaluated histologically. RESULTS: Histological evaluation showed a complete ingrowth of the osseous part of the osteochondral grafts. A healing or ingrowth at the level of the cartilage could not be observed. Histological evaluation of the transplanted grafts according to Mankin revealed significantly more and more severe signs of degeneration than the adjacent cartilage, such as cloning of chondrocytes and irregularities of the articular surface. CONCLUSION: We found no connecting tissue between the transplanted and the adjacent cartilage and histological signs of degeneration of the transplanted hyaline cartilage. In the light of these findings, long-term results of autologous osteochondral grafts in human beings have to be followed critically.     

Repair of articular cartilage defects: part II. Treatment options

Articular cartilage injuries result in numerous clinical symptoms, such as pain and decreased functional levels. Current therapeutic options being used include articular surface debridement, such as chondral shaving, abrasion chondroplasty, and subchondral perforation; soft-tissue arthroplasties, such as perichondrial and periosteal grafts; and osteochondral transplantation. None of these therapies, however, has resulted in the successful regeneration of a hyaline-like tissue that withstands normal joint loading and activity over prolonged periods. As a result, research is also being conducted on alternative therapeutic procedures to enhance the repair process and to stimulate the regeneration of a repair tissue with hyaline-like structural and biologic properties. Part I of this paper, which was published in January, discussed the basic science of cartilage healing. Part II presents the treatment options.     

Fresh osteochondral allografts

Fresh osteochondral allografts have a long clinical history and have demonstrated use in a wide spectrum of knee joint pathology. The allografting procedure takes advantage of the unique characteristics of osseous and chondral tissue components. Transplanted bone is readily incorporated by the host while the articular cartilage survives transplantation. Allografts have demonstrated >75% clinical success in the treatment of focal femoral condyle lesions due to trauma, chondral injury, osteochondral trauma, osteochondritis dissecans, avascular necrosis, and post-traumatic reconstruction. Fresh allografts also are finding an increasing role in the salvage of difficult cases that have failed other cartilage procedures, and particularly in individuals who are believed to be too young and active for joint arthroplasty. Further refinements in the technical aspects of the allografting procedure, as well as further understanding of the biology of osteochondral allografts, should lead to improved clinical outcomes.     

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.