Introduction. Osteoarthritis (OA), a painful, debilitating joint disease, often caused by excessive joint stress, is a leading cause of disability (World Health Organisation, 2003) and increases with age and obesity. A 5° varus malalignment increases loading in the medial knee compartment from 70% to 90% (Tetsworth and Paley, 1994). Internal unloading implants, placed subcutaneously upon the medial aspect of the knee joint, are designed to offload the medial compartment of the knee without violating natural joint tissues. The aim of this study is to investigate the effect of an unloading implant, such as the Atlas™ knee system, on stress within the tibiofemoral joint with different grades of cartilage defects. Methods. To simulate surgical treatment of medial knee OA, a three-dimensional computer-aided design of an Atlas™ knee system was virtually fixed to the medial aspect of a validated finite element knee model (Mootanah, 2014), using CATIA v5 software (Dassault Systèmes, Velizy Villacoublay, France). The construct was meshed and assigned material properties and boundary conditions, using Abaqus finite element software (Dassault Systèmes, Velizy Villacoublay, France). A cartilage defect was simulated by removing elements corresponding to 4.7 mm. 2. The international cartilage repair society (ICRS) Grade II and III damage were simulated by normalized defect depth of 33% and 67%, respectively. The femur was mechanically grounded and the tibia was subjected to loading conditions corresponding to the stance phase of walking of a healthy 50-year-old 68-Kg male with anthropometrics that matched those of the cadaver. Finite element analyses were run for peak shear and von Mises stress in the medial and lateral tibiofemoral compartments. Results. Von Mises stress distribution in the tibial cartilage, with ICRS Grade II and III defects, without the unloading implant, at the end of weight acceptance (15% of the gait cycle) were analysed. The internal unloading implant reduces peak von Mises stress by 40% and 43% for Grade II and Grade III cartilage defects, respectively. The corresponding reductions in shear stress are 36% and 40%. Consistent reduction in peak von Mises stress values in the medial cartilage-cartilage and cartilage-meniscus contact areas were predicted throughout the stance phase of the gait cycle for ICRS Grade II defect. Similar results were obtained for Grade III defect and for peak shear stress values. There were no overall increases in peak von Mises stress values in the lateral tibial cartilage. Discussion and Conclusions. The internal unloading implant is capable of reducing von Mises and shear stress values in the medial tibial cartilage with ICRS Grade II and III defects at the cartilage-cartilage and cartilage-meniscus interfaces throughout the stance phase of the gait cycle. This did not result in increased stress values in the lateral tibial cartilage. Our model did not account for the viscoelastic effects of the cartilage and meniscus. Results of this study are based on only one knee specimen. The internal unloading implant may protect the cartilage in individuals with medial knee osteoarthritis, thereby delaying the need for knee replacements

PURPOSE. Recently, in tissue engineering several methods using stem cells have been developed to repair chondral and osteochondral defects. Most of these methods rely on the use of scaffolds. Studies in the literature have demonstrated, first in animals and then in humans, that the use of mesenchymal stem cells withdrawn by several methods from adipose tissue allows to regenerate hyaline articular cartilage. In fact, it has been cleared that adipose-derived cells have multipotentiality equivalent to bone marrow-derived stem cells and that they can very easily and very quickly be isolated in large amounts enabling their immediate use in operating room for one-step cartilage repair techniques. The purpose of this study is to evaluate the therapeutic effect of adipose-derived stem cells on cartilage repair and present our experience in the treatment of knee cartilage defects by the novel AMIC REPAIR TECHNIQUE AUGMENTED by immersing the collagen scaffold with mesenchymal stem cells withdrawn from adipose tissue of the abdomen. MATERIALS AND METHODS. Fat tissue processing involves mechanical forces and does not mandatorily require any enzymatic or chemical treatment in order to obtain the regenerative cells from the lipoaspirate. In our study, mesenchymal adipose stem cells were obtained by non-enzymatic filtration or microfragmentation of lipoaspirates of the abdomen adipose tissue that enabled the separation of the stromal vascular fraction and were used in one-step reconstruction of knee cartilage defects by means of this new AUGMENTED AMIC TECHNIQUE. The focal defects underwent bone marrow stimulation microfractures, followed by coverage with collagen double layer resorbable membrane (Chondro-gide. TM. -Geistlich Pharma AG, Wolhusen, Switzerland) soaked in the cells obtained from fat in 18 patients, aged between 31 and 58 years, at the level of the left knee in 10 cases and in the right in eight, with follow-up ranging between 12 and 36 months. RESULTS: Surgical procedures have been completed without technical problems neither intraoperative or early postoperative complications. The evaluation scores (IKDC, KOOS and VAS) showed a significant improvement, more than 30%, at the initial 6 months follow-up and furtherly improved in the subsequent follow-ups. Also the control MRIs showed a progressive filling and maturation of the repair tissue of the defects. CONCLUSIONS. Since we are reporting a short and medium-term experience, it is not, of course, possible to provide conclusive assessment considerations on this technique, as the experience has to mature along with the progression of follow-ups. The simplicity together with the absence of intraoperative difficulties or immediate complications and the experience gained by other authors, first in animals and then in early clinical cases, makes it, however, possible to say that this can be considered one of the techniques to which resort for one-step treatment of cartilage defects in the knee because it improves patient's conditions and has the potential to regenerate hyaline-like cartilage. Future follow-up works will confirm the results

Cartilage is known to have limited intrinsic repair capabilities and cartilage defects can progress to osteoarthritis (OA). OA is a major economic burden of the 21st century, being among the leading causes of disability. The risk of disability from knee OA is as great as that derived from cardiovascular disease; a fact that becomes even more concerning when considering that even isolated cartilage defects can cause pain and disability comparable to that of severe OA. Several cartilage repair procedures are in current clinical application, including microfracture, osteochondral autograft transfer, osteochondral allograft transplantation, and autologous chondrocyte implantation (ACI). Given the economic challenges facing our health care system, it appears prudent to choose procedures that provide the most durable long-term outcome. Comparatively few studies have examined long-term outcomes, an important factor when considering the substantial differences in cost and morbidity among the various treatment options. This study reviews the clinical outcomes of autologous chondrocyte implantation at a minimum of 10 years after treatment of chondral defects of the knee. Mean age at surgery was 36 ± 9 years; mean defect size measured 8.4 ± 5.5cm2. Outcome scores were prospectively collected pre- and postoperatively at the last follow up. We further analyzed potential factors contributing to failure in hopes of refining the indications for this procedure. Conclusions: ACI provided durable outcomes with a survivorship of 71% at 10 years and improved function in 75% of patients with symptomatic cartilage defects of the knee at a minimum of 10 years after surgery. A history of prior marrow stimulation as well as the treatment of very large defects was associated with an increased risk of failure

Hypothesis. Cartilage defects pretreated with marrow stimulation techniques will have an increased failure rate. The first 321 consecutive patients treated at one institution with autologous chondrocyte implantation for full-thickness cartilage defects that reached more than two years of follow-up were evaluated by prospectively collected data. Patients were grouped based on whether they had undergone prior treatment with a marrow stimulation technique. Outcomes were classified as complete failure if more than 25% of a grafted defect area had to be removed in later procedures because of persistent symptoms. Results. There were 522 defects in 321 patients (325 joints) treated with autologous chondrocyte implantation. On average, there were 1.7 lesions per patient. Of these joints, 111 had previously undergone surgery that penetrated the subchondral bone; 214 joints had no prior treatment that affected the subchondral bone and served as controls. Within the marrow stimulation group, there were 29 (26%) failures, compared with 17 (8%) failures in the control group. Conclusion. Defects that had prior treatment affecting the subchondral bone failed at a rate three times that of nontreated defects. The failure rates for drilling (28%), abrasion arthroplasty (27%), and microfracture (20%) were not significantly different—possibly because of the lower number of microfracture patients in this cohort (25 of 110 marrow-stimulation procedures). The data demonstrate that marrow stimulation techniques have a strong negative effect on subsequent cartilage repair with autologous chondrocyte implantation and, therefore, should be used judiciously in larger cartilage defects that could require future treatment with autologous chondrocyte implantation. Unlike coventional wisdom, MSTs do ‘burn bridges’

Autologous matrix-induced chondrogenesis (AMIC) is a new treatment option for full-thickness cartilage defect repair using the well-known microfracturing technique combined with a porcine collagen type I/III matrix implant and partially autologous fibrin sealant. A retrospective study has being carried out to investigate the objective and subjective clinical outcome of this procedure over a period of up to 2 years after the operation. 18 patients (10 male, 8 female) with localised cartilage defects were treated with AMIC. The mean age was 37 13 years. Defects treated were localised retropatellar (6), on the medial femoral condyle (7), on the lateral femoral condyle (2) and multiple lesions (3). During the clinical follow-up these patients were evaluated with the help of 3 different scores (IKDC score, Cincinnati score, Lysholm-Gillquist score). For the collective of 18 patients, one or more years had elapsed since the operation at the time this study was completed. 10 patients were included into the 2-year evaluation. The IKDC Score showed a mean improvement from 28 to 58 out of 100 at 1-year and from 25.5 to 69 out of 100 at 2-years post-operative. The Cincinnati and Lysholm-Gillquist scores showed the same tendency with an improvement of about 40 pecent at 1 year and about 55 percent at 2 years compared to pre-operative value. The improvement in the IKDC Score as well as the Cincinnati and Lysholm-Gillquist suggest that AMIC is a promising alternative in the treatment of local cartilage defects in the knee with good short and possibly mid-term results. Further follow up will reveal, if the good results are durable and AMIC, as matrix enhanced microfracturing technique can become a valuable, recognised cartilage repair technique

Gel-based autologous chondrocyte implantation (ACI) over the years have shown encouraging results in repairing the articular cartilage. More recently, the use of cultured mesenchymal stem cells (MSC) has represented a promising treatment option with the potential to differentiate and restore the hyaline cartilage in a more efficient way. This study aims to compare the clinical and radiological outcome obtained in these two groups. Twenty-eight consecutive symptomatic patients diagnosed with full-thickness cartilage defects were assigned to two treatment groups (16 patients cultured bone marrow-derived MSC and 12 patients with gel-type ACI). The MSC group patients underwent microfracture and bone marrow aspiration in the first stage and injection of cultured MSC into the knee in the second stage. Clinical and radiological results were compared at a minimum follow up of five years. There was excellent clinical outcome noted with no statistically significant difference between the two groups. Both ACI and MSC group showed significant improvement of the KOOS, Lysholm and IKDC scores as compared to their preoperative values and this was maintained at 5 years follow up. The average MOCART score for all lesions was also nearly similar in the two groups. The mean T2* relaxation-times for the repair tissue and native cartilage were 27.8 and 30.6 respectively in the ACI group and 28 and 29.6 respectively in the MSC group. Use of cultured MSC is less invasive, technically simpler and also avoids the need for a second surgery as compared to an ACI technique. With similar encouraging clinical results seen and the proven ability to restore true hyaline cartilage, cultured MSC represent a favorable treatment option in articular cartilage repair

Introduction. The purpose of this study is to evaluate the early functional outcome and activity level in athletes and soldiers with large full thickness cartilage defects of the knee that underwent either ‘classic’ autologous chondrocyte implantation using periosteal flap coverage (ACI-P) or 3-D matrix-assisted chondrocyte implantation (ACI-M). Methods. Between April 2002 and January 2004, 19 patients (15 male, 4 female, average age 32.2 years) with 22 full-thickness cartilage defects in 19 knees were treated with ACI in our centre. The mean post-injury interval was 39.8 months whereas 17 (89.5%) patients had undergone at least one surgical procedure before ACI. The average defect size was 6.54 cm. 2. (located in MFC:7, LFC:7 or trochlear:2 while 3 patients had bifocal lesions in both LFC and TRC). Novocart. ¯. cultured chondrocytes with periosteal flap coverage were used in 11 patients and Novocart-3D. ¯. cell impregnated collagen patch in 8. The functional outcome was evaluated with IKDC form, Tegner activity scale and Lysholm score after a mean follow-up period of 26.5 months. Results. The average IKDC and Lysholm scores were improved from 39.16 and 42.42 pre-operatively to 62.4 and 69.4 at the latest follow-up respectively. The mean Tegner activity scale was 8.73 before injury, 3.63 pre-operatively and 5.21 at the latest follow-up. There was no statistically significant difference between the two groups regarding the clinical outcome and the overall athletic or military performance. Second-look arthroscopy was performed in 11 (57.8%) patients due to persistent pain and/or mechanical symptoms. Generally, the ACI site showed adequate graft integration except for one partial failure. Conclusions. The early results of ACI in high-performance athletes and professional soldiers are not as good as other recent studies suggest. Motivational issues during prolonged rehabilitation, patient age and very large defects may influence early results in this select group of patients

Background:. Full thickness cartilage defect of the knee frequently resulted in fibrous tissue formation, and larger lesions often lead to degenerative arthritis of the knee. Many techniques are designed to repair the cartilage defect including chondrocyte transplantation, microfracture and osteochondral graft. Each method has achieved some success but no universal results. Autologus osteochondral graft has gained in clinical popularity because of its technical feasibility and cost effectiveness. Purpose:. The purpose of this retrospective study was to evaluate the medium-term results of autologous osteochondral graft for focal contained articular cartilage defects of the knee in 25 patients with 26 knees with 2- to 7-year follow-up. Patients and Methods:. The cohort consisted of 17 men and 8 women with an average age of 31.3 ± 11.8 (range 20 to 65) years. One patient had bilateral knees. The diagnosis included 9 osteonecrosis, 10 osteochondritis dessicans, and 7 traumatic defects. A 1.0 mm oversized 10 mm long ossteochondral plug was harvested from either from the sulcus terminalis or the intercondylar notch, and implanted into the recipient site The numbers of osteochondral plug ranged from 1 to 3. In larger lesions, osteochondral grafts were implanted in the weight bearing area, and microfracture in non-weight bearing area. Postoperative management included crutch walking with non-weight bearing for 6 weeks, then partial weight bearing for another 6 weeks before full weight bearing. Range of knee motion, quadriceps and hamstring strengthening exercises were encouraged. The evaluations included functional assessment, radiograph of the knee and second look arthroscopy. Results:. At follow-up of 52.9 ± 20.3 (range 25 to 84) months, the results were 50% excellent, 35% good, 11% fair and 4% poor. Overall satisfactory results were noted in 85%. The improvements in pain and function of the knee ranged from 8 to 16 weeks after surgery. There was no correlation of the clinical results with the diagnosis of the lesion. However, the lesion size greater than 500 mm. 2. is associated with failure. Radiographic degenerative changes were noticed in 6 (23%) and 7 (27%) in medial compartment, 5 (19%) and 5 (19%) in lateral compartment, and 1 (4%) and 2 (8%) in the patellofemoral compartment pre- and postoperatively (P > 0.05). Twelve knees underwent a second look arthroscopy. Of the 11 asymptomatic knees, 8 knees with the defect smaller than 500 mm. 2. showed complete bonding of the graft to the adjacent host cartilage, and 3 cases showed minimal fissuring and fibrous tissue formation between graft and host tissue. One symptomatic knee with greater than 500 mm. 2. lesion showed extensive fibrous tissue between the graft and host cartilage. Conclusion:. Autologous osteochondral graft provides good or excellent results in 85% of patients with focal contained chondral and osteochondral defects of the knee. There was no correlation of the clinical results with the nature of the disease and the size of the lesion smaller than 500 mm. 2. Any lesion larger than 500 mm. 2. is prone to poor clinical outcome

Introduction. We describe five results of a novel single stage arthroscopic technique for the treatment of articular cartilage defects of the knee. This involves micro drilling and application of Atelo-collagen (Coltrix) and fibrin gel scaffold. Materials and Method. The preclinical study involved two groups of rabbits treated with micro-drilling, and micro-drilling with Atelo-collagen and fibrin gel. New cartilage was subjected to staining with H&E for tissue morphology, toluidine blue (collagen) and safranin O (GAG), immunohistochemistry with antibodies for collagen type I and II, and scanning and transmission electron microscopy to analyse the microstructural morphologies. The micro-drilling with Atelo-collagen, fibrin gel scored better than the micro-drilling alone. Patients (n=30) with symptomatic ICRS grade III/IV chondral defects (lesion size 2–8cm. 2. ) are recruited for this prospective study. The surgical procedure involved micro-drilling and application of Atelo–collagen and fibrin gel under CO. 2. insufflation. Patients underwent morphological evaluation with MRI (T2*-mapping and d-GEMRIC scans). Clinical assessment was done with Lysholm, IKDC and KOOS scores. Radiological assessment was performed with MOCART score. Results. At five years, Lysholm score was 74, compared to 49 pre-operatively (p<0.05). KOOS (symptomatic) improved to 92 from 62 (p<0.05). IKDC (subjective) went to 78 from 40 (p<0.05). The mean T2* relaxation-times for the repair tissue and native cartilage were 26 and 29.9 respectively. Average MOCART score for all lesions was 70. Conclusion. This technique shows encouraging clinical results at five-year follow-up. The morphological MRI shows good cartilage defect filling and the biochemical MRI suggests hyaline like repair tissue

Chondral defects of the knee are common and often seen in young and active individuals. A novel single stage arthroscopic technique for the treatment of articular cartilage defects in the knee is described. This involves microfracture and application of concentrated bone marrow aspirate cells (BMAC) with fibrin and Hyaluronic Acid as a gel. After a representative preclinical study, the 5 year results of a prospective clinical study are presented. The pre-clinical study involved two groups of rabbits with standardised lesions treated with microfracture alone and microfracture combined with fibrin/HA/BMAC application. New cartilage from both groups was subjected to staining with H&E for tissue morphology, toluidine blue (collagen) and safranin O (GAG), immunohistochemistry with antibodies for collagen type I and II, and scanning and transmission electron microscopy to analyse the microstructural morphologies. The fibrin/HA/BMAC group scored better than the microfracture group on all tests. A subsequent prospective clinical study patients (n=60) with symptomatic ICRS grade III/IV chondral defects (lesion size 2–8cm2). The surgical procedure involved debridement of the lesion, micro-fracture and application of fibrin/HA/BMAC gel under CO2 insufflation. Patients underwent morphological evaluation with MRI (T2*-mapping and d-GEMRIC scans). Clinical assessment employed the Lysholm, IKDC and KOOS scores while radiological assessment was performed with MOCART score. At 5 years, Lysholm score was 78, compared to 51 pre-operatively (p<0.05). KOOS (symptomatic) improved to 90 from 66 (p<0.05). IKDC (subjective) went to 80 from 39 (p<0.05). The mean T2* relaxation-times for the repair tissue and native cartilage were 26 and 29.9 respectively. Average MOCART score for all lesions was 70. This technique shows encouraging clinical results at 5 year follow-up. The morphological MRI shows good cartilage defect filling and the biochemical MRI suggests hyaline like repair tissue

We describe a novel single stage arthroscopic repair procedure for articular cartilage defect in the knee. The aim of the study was to evaluate the clinical and radiological outcomes at two years. The pre-clinical study involved two groups of New Zealand rabbits, treated with microfracture alone and microfracture combined with fibrin gel and concentrated bone marrow aspirate cells (BMAC) application. New cartilage from both groups was studied with histological staining, immunohistochemistry and electron microscopy. The fibrin gel-BMAC group scored better than the microfracture group on all counts. This is a prospective study of 30 patients with symptomatic ICRS grade III/IV chondral defects, ranging from 2–8 cm. 2. , which were assessed clinically and radiologically. The surgical procedure involved debridement of the lesion, microfracture and arthroscopic application of concentrated BMAC with fibrin gel under CO. 2. insufflation. Patients underwent morphological MRI, quantitative T2*-mapping and d-GEMRIC scan. Clinical assessment was carried out using the Lysholm, IKDC and KOOS scores while radiological assessment used the MOCART score. At 2 year follow-up, Lysholm score was 80.1, as compared to 50.8 pre-operatively (p < 0.05). KOOS (symptomatic) was 92.1, as compared to 65.7 pre-operatively. IKDC (subjective) was 83, up from 39 preoperatively. The mean T2* relaxation-times for the repair tissue and native cartilage were 29.1 and 29.9 respectively. Average MOCART score for all lesions was 72. Our technique shows encouraging clinical and radiological results. The morphological MRI shows good cartilage defect filling and the biochemical MRI (T2*-mapping) suggests hyaline like repair tissue

It is reported that more than 10 million Japanese suffer from arthrosis. To cure these cartilage defects, total joint replacements, which are the most popular treatment methods for severe disease situation, have been operated as about two hundred thousand cases a year in Japan. Although the implants made of either ceramics, metals or plastics have high wear resistance quality, it becomes apparent that the endurance life of the artificial joints in considerable cases is limited by aseptic loosening to between 10–15 years. Here we focused on a poly(vinyl alcohol) (PVA) hydrogel as an artificial cartilage tissue to make an improvement of friction surface of the artificial joints. In this paper, we observed morphology of wear particles and assessed immune responses of wear particles from the hydrogel for confirming the validity of the gel as a biotribological material. We prepared 20 w/w% of PVA hydrogel by repeated freezing-thawing method. The number of the freezing-thawing cycles was five times. Polymerization degree and saponification degree of PVA (Kishida Chemical Co. Ltd., Japan) were 2000 and 98.4–99.8 mol%, respectively. To collect the wear particles of PVA hydrogel, we processed wear testing by using a purpose-build wear test machine of reciprocating pin-on-plate tribometer as shown in figure 1. We installed a Co-Cr-Mo ball of 26 mm in diameter as a stationary upper specimen and a PVA hydrogel plate of 2 mm in thickness as reciprocating lower specimen in a water bath. The lubricant was a distilled water containing eluted PVA which PVA-FT gel had been soaked in, filtered by 0.22 μm and autoclaved, subsequently. Siding speed was 50 mm/s and the total sliding distance was 3 km. We observed the wear particles which had been dried in a desiccator, by scanning electron microscope (SEM; SU8000, Hitachi High-Technologies). Additionally, to investigate the effect of the wear particles on response of phagocytosis of macrophages, here we used THP-1 cell line from Human acute monocytic leukemia as a macrophage, which was purchased from JCRB Cell Bank, and attached the macrophages on a dish after stimulating THP-1 by phorbol 12-myristate 13-acetate (PMA; Wako). After the wear test, we harvested the lubricant in aseptic clean hood and applied the particles to the macrophages to clarify the effect of wear particles of PVA hydrogel on immune response of the cell. To assess cytokine biosynthesis as immune responses, we assayed IL-1β and TNF-α biosynthesis in culture medium by ELISA (Thermo scientific), respectively. Figure 2 shows an SEM image of PVA hydrogel after wear test under 4.9 N loading. We observed the wear particles of varied sizes. When applying the wear particles to the macrophages in RPMI-1640 supplement with 10 v/v% fetal bovine serum, it seemed that there were not enough change on cytokine synthesis in culture medium between with/without the particles

Full thickness cartilage defects of the femoral condyles are frequent, can be highly symptomatic, and pose treatment challenges when encountered in middle-aged patients. A history of biological repair procedures is frequent and patient management is complex in order to delay joint replacement procedures in active patients. Focal metallic resurfacing provides a joint preserving bridging procedure with a clinical exit into primary arthroplasty. Methods. This study presents a review of several multicenter investigations exploring the clinical benefits and validity of focal resurfacing in 78 patients, ages 35–67, with a follow-up ranging from 2 to 6 years. All patients were treated with a 15 or 20 mm contoured resurfacing implant on the medial or lateral femoral condyle. Results. At 2 years follow up, average scores for WOMAC domains improved by over 100% (40 preop to 86 postop where 100 = best). At 3 year follow-up KOOS scores were within 88 to 102% of a normal aged matched population (domain range 72–91 where 100 = best). At a minimum of 5 years, the KOOS domains were close to normative reference levels on pain relief, symptoms, and activities of daily living (range 83–89% of normal). Radiographic results demonstrated solid fixation, preservation of joint space, and no change in the osteoarthritic stage. Conclusion. The procedure adds a new layer to reconstructive treatment options in the long-term management of knee arthrosis and arthritis and allows for a clinical alternative to lifestyle changes required by many patients who failed cartilage procedures and continue to have an isolated symptomatic defect precluding them from joint arthroplasty

Introduction. The treatment of distal femoral cartilage defects using autologous chondrocyte implantation (ACI) and matrix-guided autologous chondrocyte implantation (MACI) is become increasingly common. This prospective 7-year study reviews and compares the clinical outcome of ACI and MACI. Methods. We present the clinical outcomes of 159 knees (156 patients) that have undergone autologous chondrocyte implantation from July 1998. One surgeon performed all operations with patients subsequently assessed on a yearly basis using 7 independent validated clinical, functional and satisfaction rating scores. Results. Modified Cincinnati, Patient Functional Outcome and Lysholm & Gilchrist clinical rating scores all showed significant improvements compared to pre-operative levels (p<0.0001). Although ACI scores are superior at one year (p<0.05) there is no significant difference between ACI and MACI at 2 years. Visual Analogue Score and Bentley Functional rating score showed significant improvements compared to pre-operative levels (p<0.0001) with ongoing yearly sequential improvement. Patient Rating and Brittberg scores, both subjective patient scores, similarly showed continuing improvements in the years following surgery. Discussion. ACI and MACI produce significant improvements in knee function when compared to pre-operative levels with continued sequential improvement in outcomes for up to seven years. The initial data suggests a superior rate of clinical improvement using the MACI technique

INTRODUCTION. Osteochondral defects are still a challenge for the orthopaedic surgeon, since most of the current surgical techniques lead to fibrocartilage formation and poor subchondral regeneration, often associated to joint stiffness and/or pain. Thinking of the ideal osteochondral graft from both the surgical an commercial point of view, it should be an off-the-shelf product; this is the research direction and the explanation for the new biomaterials recently proposed to repair osteochondral defect inducing an “in situ” cartilage regeneration starting from the time of the implantation into the defect site. For the clinical pilot study we performed, a newly developed nanostructured biomimetic scaffold was used to treat chondral and osteochondral lesions of the knee; its safety and manageability, as much as the surgical procedure reproducibility and the clinical outcome, were evaluated in order to test its intrinsic potential without any cells colture aid. MATERIALS AND METHODS. A new osteochondral scaffold was obtained by enucleating equine collagen type 1 fibrils with hydroxyapatite nanoparticles in 3 different layers with 3 different gradient ratios at physiological conditions. 30 patients (9F, 21M, mean age 29,3yy) affected by either chondral or osteochondral lesions of the knee (8 medial femoral condyles, 5 lateral femoral condyles, 12 patellae, 8 femoral throcleas) underwent the scaffold implantation from January to July 2007. The sizes of the lesions were in between 2 and 6 squared cm. All patients and their clinical outcome were analyzed prospectively at 6, 12, 24 and 36 months using the Cartilage standard Evaluation Form as proposed by ICRS and an high resolution MRI. RESULTS. We observed a statistically significant scores improvement and function recovery comparing the pre-operative to the follow-up parameters evaluated. Moreover, we noticed a better improvement from 12 to 24mm follow up while the good results gained at 2yy were confirmed at 3yy follow up evaluation. The MOCART scoring scale was used to analyze the MRIs. In 80% of cases we obtained a complete filling of the cartilage defect and in some patients we even appreciated articular surface congruency. In this series we report 1 failure followed by a re-operation with different technique. CONCLUSIONS. This new minimally invasive one-step surgical approach to osteochondral defects seems to be an easy and effective procedure. The results obtained are very encouraging and this procedure show satisfactory outcomes even in big osteochondral defects

Hyaline articular cartilage has been known to be a troublesome tissue to repair once damaged. Since the introduction of autologous chondrocyte implantation (ACI) in 1994, a renewed interest in the field of cartilage repair with new repair techniques and the hope for products that are regenerative have blossomed. This article reviews the basic science structure and function of articular cartilage, and techniques that are presently available to effect repair and their expected outcomes.

Objectives

Salubrinal is a synthetic agent that elevates phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α) and alleviates stress to the endoplasmic reticulum. Previously, we reported that in chondrocytes, Salubrinal attenuates expression and activity of matrix metalloproteinase 13 (MMP13) through downregulating nuclear factor kappa B (NFκB) signalling. We herein examine whether Salubrinal prevents the degradation of articular cartilage in a mouse model of osteoarthritis (OA).