Topographic variation in redifferentiation capacity of chondrocytes in the adult human knee joint.

OBJECTIVES: The aim of this study was to investigate the topographic variation in matrix production and cell density in the adult human knee joint. Additionally, we have examined the redifferentiation potential of chondrocytes expanded in vitro from the different locations. METHOD: Full thickness cartilage-bone biopsies were harvested from seven separate anatomical locations of healthy knee joints from deceased adult human donors. Chondrocytes were isolated, expanded in vitro and redifferentiated in a pellet mass culture. Biochemical analysis of total collagen, proteoglycans and cellular content as well as histology and immunohistochemistry were performed on biopsies and pellets. RESULTS: In the biochemical analysis of the biopsies, we found lower proteoglycan to collagen (GAG/HP) ratio in the non-weight bearing (NWB) areas compared to the weight bearing (WB) areas. The chondrocytes harvested from different locations in femur showed a significantly better attachment and proliferation ability as well as good post-expansion chondrogenic capacity in pellet mass culture compared with the cells harvested from tibia. CONCLUSION: These results demonstrate that there are differences in extra cellular content within the adult human knee in respect to GAG/HP ratio. Additionally, the data show that clear differences between chondrocytes harvested from femur and tibia from healthy human knee joints exist and that the differences are not completely abolished during the process of de- and redifferentiation. These findings emphasize the importance of the understanding of topographic variation in articular cartilage biology when approaching new cartilage repair strategies.

Rehabilitation after cell transplantation for cartilage defects.

Rehabilitation is a key element of successful treatment of cartilage defects with cell transplantation. The process of graft maturation takes approximately 18 months and cannot be accelerated, but requires carefully introduced steps leading to early recovery of joint function. Rehabilitation starts at 8 hours after surgery with the continuous passive motion (CPM) exercises and physiotherapy. For the first 6 weeks, patients continue with CPM in the range of 0 degrees to 45 degrees for femoral and tibial defects and 0 degrees to 30 degrees for patellofemoral joint reconstruction. Isometric muscle training and scar manual therapy are introduced. Patients are allowed to weight-bear as tolerated from the second week after surgery. After this initial phase, from 6 to 8 weeks after surgery, rehabilitation is accelerated with increased load-bearing and progressive range of motion to full flexion. Usually patients are able to walk without crutches in this time. Proprioceptive training is introduced with the advance of pain-free full range of motion and no discomfort with full weight-bearing. At 6 months after surgery, most patients recover joint function, making it possible for them to return to daily living activities. However, they need to continue with muscle, proprioceptive, and sports-specific rehabilitation exercises. The rehabilitation process is complicated, requiring close cooperation between the patient and surgeon-physiotherapist team to understand the symptoms and address them in a timely fashion.

Fresh bone marrow and periosteum transplantation for cartilage defects of the knee.

The aim of work was to analyze clinical effectiveness of fresh bone marrow and periosteum transplantation in the treatment of traumatic or degenerative cartilage defects. The 14 patients in this study had a mean age of 37 years. Bone marrow aspirated from the iliac crest was implanted under the periosteum sutured over the defect. Three, 6, and 12 months postoperatively, the patients were evaluated with the analogue pain scale, modified Cincinnati score, and IKDC questionnaires. All patients were evaluated with magnetic resonance imaging (MRI) at 3 and 12 months postoperatively. After 3 and 6 months significant improvement was observed in eight patients. After 12 months, 12 patients were classified as normal or nearly normal in the IKDC examination form, and two as abnormal. Mean IKDC Subjective Knee Score was 86.57. MRI findings revealed surfaces with correct contours and continuity, without changes in subchondral bone in all but one patient. There was a correlation between a large size of defect or an osteoarthritic nature of the changes and poor results.

Algorithms for articular cartilage repair.

The treatment of cartilage lesions in the knee joint is still controversial. There are many approaches for restoration of diseased cartilage, but no single procedure is universally accepted for each kind of lesion and every patient. The goal of any reconstructive or regenerative procedure is to relieve the symptoms of the cartilage defect and restore joint function. Most current approaches to cartilage repair accomplish this objective. However, it is clear that there is no "gold standard" in the treatment of cartilage defects and the choice of treatment is the key element. The patient with knee joint pain undergoes a detailed history and clinical examination. It is important to evaluate the factors like the nature of the cartilage failure, the joint findings, leg alignment, and muscle balance, as well as patient's activity level, expectations, and ability to follow the rehabilitation regimen. This study sought to create a clinical algorithm for management of diseased articular knee joint cartilage that was suitable for patients with traumatic full-depth lesions.

Generating autogenous cartilage on the basis of subperichondrial grafts of demineralized bone matrix with local stimulation by growth factors.

Cartilage tissue acquired de novo is a very attractive material for the surgical reconstruction of joint surfaces, trachea, and maxillofacial elements. One of the primary challenges for tissue engineering is to determine the procedures that lead to the creation of material meeting the established qualitative and quantitative criteria. The goal of this work was to determine whether and how growth factors (IGF-1 and FGF) and ethyl alcohol administered locally affect the course and final outcome of the chondrogenetic process under in vitro conditions in New Zealand rabbits. In order to generate cartilage, a collagen scaffold (demineralized ZMK bone matrix) was used, wrapped in a pedunculated flap of perichondrium (from the rabbit's ear), which, beginning on the 3rd day after the operation, was injected with growth factors every 3 days. Grafts were collected in the 3rd and 6th week after the ZMK implantation, and the silvers made from them were stained for the presence of collagen II, collagen I, and macrophages, and analyzed morphometrically. It was found that the application of growth factors only slighty, intensified the synthesis of collagen II, and had no effect on the degree of macrophage infiltration or collagen I contents, while the numerous injections exerted a negative impact on the architecture of the newly-formed tissue and contributed to an increased number of complications (hematomas, infections).

The undesirable side-effects of non-steroidal anti-inflammatory drugs.

Non-steroidal anti-inflammatory drugs (NSAD) are among the most commonly used medications. Many of them, such as ibuprofen, naproxen and aspirin, are widely advertised in the media and available without prescription. NSADs have anti-inflammatory effects, and some of them (aspirin, ibuprofen) are also antipyretic. The basic mechanism of their action is based on the inhibition of the enzyme cascade in the metabolism of arachidonid acid - cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2) - and as a result inhibition of prostaglandin production. The undesirable side-effects of NSADs are primarily a direct result of the anti-inflammatory mechanism, and increase proportionally with the dosage. The article presents undesirable side-effects in the digestive system, the kidneys, and elsewhere. In conclusions the author point to the need for caution in using drugs of this kind.

The impact of non-steroid anti-inflammatory drugs and antibiotics on articular cartilage.

One of the essential elements in the proper functioning of articular cartilage is the proper balance of glycosaminoglycans and collagen proteins in the extracellular matrix. Any disproportion of this balance can produce degenerative changes. Certain pharmaceutical agents can induce changes of this kind. The present article provides a review of current opinions on the impact of non-steroid anti-inflammatory drugs and antibiotics on articular cartilage.

The osteogenetic potential of bone-marrow mesenchymal stem cells.

Multi-potential mesenchymal marrow Wells hale the capability to differentiate into a wide range of connective tissue cells, including the tissues involved in the locomotor apparatus. Progenitor cells can be easily obtained from the bone marrow of adult patients, and may provide an alternative to allografts or autografts of bone tissue.