Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome. The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010. The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 409 mm. 2. (range 64 to 2075 mm. 2. ). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites. High failure rates were noted in those with previous cartilage regenerative procedures or evidence of early osteoarthritis and those with transplantation to multiple sites. Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure

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’

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

Purpose. We report on minimum 2 year follow-up results of 71 patients randomised to autologous chondrocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the knee. Introduction. ACI is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. Results. 71 patients with a mean age of 33 years (15-48) were randomised to undergo either an ACI-C or a MACI. 37 had ACI-C and 34 MACI. The mean size of the defect was 5.0cm2. Mean duration of symptoms was 104.4 months (9-456). Mean follow-up was 33.5 months (24-45). Functional assessment using the modified Cincinnati knee score, the Bentley functional rating score and the visual analogue score was carried out. Assessment using the modified Cincinnati knee score showed a good to excellent result in 57.1% of patients followed up at 2 years, and 65.2% at 3 years in the ACI-C group; and 63.6% of patients at 2 years, and 64% at 3 years in the MACI group. Arthroscopic assessments showed a good to excellent International Cartilage Repair Society score in 81.8% of ACI-C grafts and 50% of MACI grafts. Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in biopsies of 56.3% of the ACI-C grafts and 30% of the MACI grafts after 2 years. Conclusion. At this stage of the trial we conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI

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

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

Osteoarthritis is a global problem and the treatment of early disease is a clear area of unmet clinical need. Treatment strategies include cell therapies utilising chondrocytes e.g. autologous chondrocyte implantation and mesenchymal stem/stromal cells (MSCs) e.g. microfracture. The result of repair is often considered suboptimal as the goal of treatment is a more accurate regeneration of the tissue, hyaline cartilage, which requires a more detailed understanding of relevant biological signalling pathways. In this study, we describe a modulator of regulatory pathways common to both chondrocytes and MSCs. The chondrocytes thought to be cartilage progenitors are reported to reside in the superficial zone of articular cartilage and are considered to have the same developmental origin as MSCs present in the synovium. They are relevant to cartilage homeostasis and, like MSCs, are increasingly identified as candidates for joint repair and regenerative cell therapy. Both chondrocytes and MSCs can be regulated by the Wnt and TGFβ pathways. Dishevelled Binding Antagonist of Beta-Catenin (Dact) family of proteins is an important modulator of Wnt and TGFβ pathways. These pathways are key to MSC and chondrocyte function but, to our knowledge, the role of DACT protein has not been studied in these cells. DACT1 and DACT2 were localised by immunohistochemistry in the developing joints of mouse embryos and in adult human cartilage obtained from knee replacement. RNAi of DACT1 and DACT2 was performed on isolated chondrocytes and MSCs from human bone marrow. Knockdown efficiency and cell morphology was confirmed by qPCR and immunofluorescence. To understand which pathways are affected by DACT1, we performed next-generation sequencing gene expression analysis (RNAseq) on cells where DACT1 had been reduced by RNAi. Top statistically significant (p < 0 .05) 200 up and downregulated genes were analysed with Ingenuity® Pathway Analysis software. We observed DACT1 and DACT2 in chondrocytes throughout the osteoarthritic tissue, including in chondrocytes forming cell clusters. On the non-weight bearing and visually undamaged cartilage, DACT1 and DACT2 was localised to the articular surface. Furthermore, in mouse embryos (E.15.5), we observed DACT2 at the interzones, sites of developing synovial joints, suggesting that DACT2 has a role in cartilage progenitor cells. We subsequently analysed the expression of DACT1 and DACT2 in MSCs and found that both are expressed in synovial and bone marrow-derived MSCs. We then performed an RNAi knockdown experiment. DACT1 knockdown in both chondrocyte and MSCs caused the cells to undergo apoptosis within 24 hours. The RNA-seq study of DACT1 silenced bone marrow-derived MSCs, from 4 different human subjects, showed that loss of DACT1 has an effect on the expression of genes involved in both TGFβ and Wnt pathways and putative link to relevant cell regulatory pathways. In summary, we describe for the first time, the presence and biological relevance of DACT1 and DACT2 in chondrocytes and MSCs. Loss of DACT1 induced cell death in both chondrocytes and MSCs, with RNA-seq analysis revealing a direct impact on transcript levels of genes involved in the Wnt and TFGβ signalling, key regulatory pathways in skeletal development and repair

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

Purpose. Osteochondral lesions (OCL) of the talus remain a challenging therapeutic task to orthopaedic surgeons. Several operative techniques are available for treatment, e.g. autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), matrix-induced autologous chondrocyte implantation (MACI). Good early results are reported; however, disadvantages are sacrifice of healthy cartilage of another joint or necessity of a two-stage procedure. This case describes a novel, one-step operative treatment of OCL of the talus utilizing the autologous matrix-induced chondrogenesis (AMIC) technique in combination with a collagen I/III membrane. Method. 20 patients (8 female, 12 male; mean age 36, range 17–55 years) were assessed in our outpatient clinic for unilateral OCL of the talus. Preoperative assessment included the AOFAS hindfoot scale, conventional radiography, magnetresonancetomography (MRI) and SPECT-CT. Surgical procedure consisted of debridement of the OCL, spongiosa plasty from the iliac crest and coverage with the I/III collagen membrane (Chondrogide, Geistlich Biomaterials, Wolhusen, Switzerland). Clinical and radiological followup was performed after one year. Results. The mean preoperative AOFAS hindfoot scale was poor with 63.1 points (SD 19.6). At one year followup the score improved significantly (p<0.01) to 86 points (SD 12). At one year followup conventional radiographs showed osseous integration of the graft in all cases. MRI at one year showed intact cartilage covering the lesions in all cases. Conclusion. The initial results of this ongoing study are encouraging. The clinical and radiological results at one year followup are comparable with the results of ACI, OATS and MACI. The AMIC procedure is a readily available, economically efficient, one step surgical procedure. No culturing after chondrocyte harvesting or destruction of viable cartilage is necessary

Introduction. We report the initial 2 and 3 year follow-up results of this randomised controlled trial of autologous chondrocyte implantation (ACI) using porcine-derived collagen membrane as a cover (ACI-C) versus matrix-carried autologous chondrocyte implantation (MACI) for the treatment of osteochondral defects of the knee. Methods. 217 patients were randomised to have either ACI (92 patients) or MACI (125 patients). The mean age in each group was 35.1 and 33 years respectively. There were equal proportion of males and females and there was no difference in the size of lesions in each of the treatment groups. One year following surgery, patients underwent check arthroscopy (with or without biopsy) to assess the graft. Functional assessment was performed yearly by using the Modified Cincinatti Knee score, the SF-36 score, the Bentley Functional Rating Score and the Visual Analogue Score. Results. 32 patients (27 from the MACI group) were excluded from the study as they underwent additional procedures (e.g. high tibial osteotomy). In the ACI group the modified Cincinnati score increased from 45.2 pre-operatively to 56.7, 54.1, and 65.4 at 1 year, 2 years and 3 years respectively. In the MACI group the Cincinnati scores increased from 45.5 pre-operatively to 59.9, 58.9, and 63.4. Arthroscopic assessment showed a good to excellent International Cartilage Repair Society score in 91.4% of ACI-C grafts and 76.1% of MACI grafts. Hyaline-like cartilage or hyaline-like with fibrocartilage was found in biopsies of 48.6% of ACI-C grafts and 30.5% of MACI grafts. Conclusions. ACI grafts are more likely to produce hyaline-like or mixed hyaline-like cartilage and fibrocartilage with better ICRS grades than MACI grafts. However, this does not translate to a better functional outcome. More importantly, ACI and MACI had similar results that were maintained at 3 years

A prospective case control study analysed clinical and radiographic results in patients operated on with the periosteum autologous chondrocyte implantation (ACI) due to cartilage lesions on the femoral condyles over 10 years ago. 31 out of the 45 patients (3 failures, 9 non-responders, 2 others) were available for a continuous clinical (Lyshom/Tegner, IKDC, KOOS) and radiographic (Kellgren-Lawrence) follow-up at 0, 2, 5, and 10 years after the ACI procedure. The patients were sub-grouped into focal cartilage lesions (FL) – 10, osteochondritis dissecans (OCD) – 12, and cartilage lesions with simultaneous ACL reconstruction (ACL) – 9 subgroups. Lysholm, Tegner, and IKCD subjective scores revealed stable results over the period from 2 to 10 years with a significant improvement toward the pre-operative levels, but the patients had not reached their pre-injury Tegner levels. KOOS profile at 10 years was: Pain 78.6, Symptoms 78.1, Activities of daily living 82.5, Sports 56.9, and Quality of life 55.1. A 10-year IKDC knee examination classified operated knees as: 14 normal, 10 nearly normal, 5 abnormal and 2 severely abnormal. Kellgren-Lawrence scores of 2 and above were found in 10 patients (FL 5, OCD 0, and ACL 5). Seven patients in the group required an arthroscopic re-intervention (3 ACI related, 4 ACI unrelated). ACI provided safe and stable performance of operated knees over ten years. High incidence of knee osteoarthritis in FL and ACL subgroups, and low incidence in OCD patients indicate that best long performance is expected in localised low-impact cartilage lesions of young patients

Large osteochondral defects of the glenohumeral joint are difficult to treat in young, active patients. When initial non-operative treatment with physical therapy, non-steroidal anti-inflammatory medications, corticosteroid injections, and viscosupplementation fails, surgery may become an option for some patients. Traditional shoulder arthroplasty and hemiarthroplasty provide excellent function and pain relief that can be long-lasting, but these treatments are still very likely to fail during a young patient's lifetime, and results have been unsatisfactory in many younger patients. Microfracture and autologous chondrocyte implantation (ACI) have been used in the shoulder, but their use has been limited to small defects. Other techniques that incorporate soft-tissue coverage of larger osteochondral defects have the benefit of preserving bone, but have not provided consistently good results. Advanced surgical techniques have been developed including all-arthroscopic osteochondral graft resurfacing of the humerus and glenoid for the treatment of osteoarthritis. This method of ‘biological resurfacing’ of the joint without using prosthetic implants may offer potential benefits to these young patients with shoulder arthritis including faster rehabilitation, pain relief, and easier revision surgery, if necessary. Early outcomes are encouraging in many cases, but inconsistent overall, with pain relief being the most reliable indicator of patient satisfaction

Introduction and Aim. The management of grade 4 articular cartilage defects of the knee is a great challenge and surgical techniques are evolving. This single surgeon series evaluated the results of articular cartilage implantation using matrix assisted autologous cartilage implantation (B Braun, Tetec, Reutlingen Germany) in 28 patients who had failed previous micro-fracture or chondroplasty. Material and methods. Patients with a single chronic symptomatic full thickness defect either on the femoral condyle, trochlea or the patella were included. The defect size varied from 2.5 cm2 to 9.6 cm2. The mean age was 41.3 years and the mean duration of symptoms prior to surgery was 27 months (6–96). Functional outcome was evaluated using the IKDC, KOOS, Tegner Lysholm and VAS pain scores. Patients also quantified their improvement in percentage or descriptive terms. Radiological assessment was carried out using MRI. Results. At a mean follow up of 14 months (12 to 39) there was significant improvement in the IKDC from median 32.2 to 89.2 (p<0.001); KOOS from median 32.20 to 91.2 (p <0.001); Tegner-Lysholm from median 36 to 89 (p<0.001). VAS improved from a median of 1 to 9 post surgery. All patients had subjective improvement of a minimum of 85%. There were no complications in this study. Conclusion. The study shows that articular cartilage implantation using this technique yields excellent results in symptomatic patients following failed micro-fracture or chondroplasty. Careful patient selection and rehabilitation are however paramount in achieving success

A new surgical hybrid technique involving the combination of autologous bone plug(s) and autologous chondrocyte implantation (AOsP-ACI) was used and evaluated as a treatment option in 15 patients for repair of large osteochondral defects in knee (N=12) and hip joints (N=3). Autologous Osplugs were used to contour the articular surface and the autologous chondrocytes were injected underneath a biological membrane covering the plug. The average size of the osteochondral defects treated was 4.5cm. 2. The average depth of the bone defect was 26mm. The patients had a significant improvement in their clinical symptoms at 12 months with significant increase in the Lysholm Score and Harris Hip Score (p = 0.031). The repaired tissue was evaluated using Magnetic Resonance Imaging, Computerised Tomography, arthroscopy, histology and immunohistochemistry (for expression of type I and II collagen). Magnetic Resonance Imaging, Computerised Tomography and histology at 12 months revealed that the bone plug became well integrated with the host bone and repair cartilage. Arthroscopic examination at 12 months revealed good lateral integration of the AOsP-ACI with the surrounding cartilage. Immunohistochemistry revealed mixed fibro-hyaline cartilage. We conclude that the hybrid AOsP-ACI technique provides a promising surgical approach for the treatment of patients with large osteochondral defects. This study highlights the use of this procedure in two different weightbearing joints and demonstrates good early results which are encouraging. The long term results need to be evaluated

Purpose. The rate of arthroplasty or osteotomy in patients who had undergone autologous chondrocyte implantation (ACI) for osteochondral defects in the knee was determined. Furthermore, we investigated whether any radiographic evidence of osteoarthritis (OA) prior to ACI was associated with poorer outcome following surgery. Methods. We retrospectively reviewed the medical notes and radiographs of 236 patients (mean age 34.9) who underwent ACI from 1998 to 2005 at our institution. Knee function was assessed according to the Modified Cincinnati Score (MCS) pre-operatively and at a mean of 64.3 months postoperatively (range 12 – 130). Radiographic changes were graded according to the Stanmore grading system. Results. Patients were divided into 2 groups; Group A were patients with no evidence of OA (n=72) and Group B were patients with OA (n=164). In group A, two patients required total knee replacement (TKR) or unicondylar knee replacement (UKR) and 3 required high tibial osteotomy (overall revision rate 6.9%). In group B, 34 patients required patello-femoral replacement, or UKR or TKR and 17 patients required osteotomy (overall revision rate 31.1%). This difference was significant (p < 0.01). At latest follow up, the mean MCS was significantly higher in Group A (72.5 versus 51.8, p < 0.01). Conclusions. Patients with early radiographic of evidence of OA are unlikely to gain maximum benefit from ACI. The results suggest that ACI does not prevent patients from progressing in their arthritic process and hence requiring joint replacement

To assess the clinical outcomes of patients undergoing ACI in the patellofemoral joint. Level of evidence. Therapeutic study, Level II-1 (prospective cohort study). In a prospective study to determine the clinical effectiveness of autologous chondrocyte implantation 130 patients reached a minimum follow up of two years (range, 2–9 years, average 56.5 months) after treatment involving the patellofemoral articulation. There were 77 men (59%) and 53 women (41%) with an average age of 37.5 years (range, 15-57years). The treatment groups included I) isolated patella, n = 14; II) isolated trochlea, n = 15; III) patella plus trochlea, n = 5; IV) weight bearing condyle plus patella n = 19; V) weight bearing condyle plus trochlea, n = 52; VI) weight bearing condyle plus patella plus trochlea n = 25. The average surface area per patella, n = 63, was 4.72 cm2 and per trochlea, n = 98, was 5.8cm2. The average resurfacing per knee, n = 130, was 11.03cm2. This prospective outcome study demonstrated a significant postoperative improvement in quality of life as measured by the SF-36; WOMAC, Knee Society Score, modified Cincinnati Score and a patient satisfaction survey. There were 16 failures (12%) as a result of a patella or trochlea failure. Eighty percent of patients rated their outcomes as good or excellent, 18% rated outcome as fair, and 2% rated outcome as poor. ACI is effective in the patellofemoral joint and specifically is a complementary intervention for those patients that will predictably do poorly with an isolated Fulkerson Tibial Tubercle osteotomy

Background. Autologous chondrocyte implantation (ACI) and mosaicplasty (MP) are two methods of repair of symptomatic articular cartilage defects in the adult knee. This study represents the only long-term comparative clinical trial of the two methods. Methods. A prospective, randomised comparison of the two modalities involving 100 patients with symptomatic articular cartilage lesions was undertaken. Patients were followed for ten years. Pain and function were assessed using the modified Cincinnati score, Bentley Stanmore Functional rating system and visual analogue scores. ‘Failure’ was determined by pain, a poor outcome score and arthroscopic evidence of graft disintegration. Results. Patients had a mean age at index operation of 31. There was a long mean pre-op duration of symptoms of seven years and the defects had an average of 1.5 operations (excluding arthroscopy) to the articular cartilage lesion prior to the cartilage repair surgery. The aetiology of the articular cartilage defects was mainly trauma; some patients had osteochondritis dissecans or chondromalacia patellae. Five patients were lost to follow-up. A total of 23 out of 42 mosaicplasty patients failed, 10 out of 58 ACI patients failed (p<0.001). Most patients did well for the first two years when there was a steep failure of mosaicplasty patients, after which the failure rate was more constant. There was a low steady failure rate of ACI over the 10 years. Older patients treated by ACI did worse than younger patients; age was less of a prognostic indicator in MP. Patients irrespective of gender or aetiology of the defect fared better with ACI than MP. Conclusion. At ten years, patients who underwent cartilage repair using ACI fared significantly better than those who underwent mosaicplasty

Autologous chondrocyte implantation is now a recognised treatment for patients with knee pain secondary to articular cartilage defects. The initial technique involving periosteum as the cover for the implanted cells (ACI-P) has been modified to the use of a type I/III collagen membrane (ACI-C). Matrix-induced Autologous Chondrocyte Implantation (MACI) is a technique in which autologous donor chondrocytes are implanted onto the collagen membrane and then fixed into the defect with fibrin glue. We performed a prospective randomised comparison of 247 patients (126 ACI and 121 MACI). Patients' pain and function were assessed with mean follow-up of 42 months. Function was measured using the Modified Cincinnati and Stanmore Scoring systems. Arthroscopic assessment was by the ICRS classification. The influence of the size and site of the lesion, sex, age and previous knee surgery on the results was analysed. The Modified Cincinnati score showed a mean 17.5 point rise from pre-operative scores in the ACI group and 19.6 point rise in the MACI group. Pain, measured using the Visual Analogue Score, showed an improvement in both arms of the trial. Both chondrocyte implantation methods showed improvement in 86% of patients clinically and arthroscopically, with excellent and good results in 50% and fair results in 30% of patients. 20% of patients showed no improvement in function but none were worse. There were no serious complications. Limited histological analysis showed hyaline cartilage in a higher but non-significant proportion of ACI-C cases. With over 11 years' experience in the use of both forms of cartilage implantation we have established more precisely the indications for chondrocyte implantation. Although MACI is technically a more attractive option in most cases, because of ease and speed of the procedure, longer term follow-up is required to assess the longevity of ACI-C and MACI and the effect on prevention of ‘early-onset’ Osteoarthritis

Osteochondral lesions (OCL) of the talus occur in 38% of the patients with supination external rotation type IV ankle fractures and 6 % of ankle sprains. Osteoarthritis is reported subsequently in 8–48% of the ankles. Several marrow stimulation methods have been used to treat the symptomatic lesion, including arthroscopic debridement and micro fracture. Encouraging midterm results have been reported, but longterm outcome is unknown in relation to more invasive treatments such as transfer of autologous osteoarticular tissue from the knee or talus (OATS), autologous chondrocyte implantation (ACI), frozen and fresh allograft transplantation. Aim. The aim of our study was to review our long term results of arthroscopic treatment of osteochondral lesions of the talus. Materials and methods. 65 patients underwent arthroscopic treatment of the OCL between 1993 and 2000. There were 46(71%) men and 19(29%) women. The mean age at surgery was 34.2 years. The right side was affected in 43 patients and the left side in 22 patients. Results. 40/65(61.5%) patients who underwent arthroscopic treatment of the OCL were followed up. The mean follow-up was 13.1 years (9 to 18 years). The average age at final follow was 49.6 years (25–80 years). 15 (39.5%) patients reported poor, 14 (36.8%) fair, 9 (23.6%) good outcomes based on the Berndt and Harty criteria. 20/40 patients (50 %) needed further surgery. This appears a significant deterioration since this cohort were studied at 3.5 years, when the clinical results were 21.3% poor, 26.2% fair and 52.3% good, although losses to followup make exact comparison impossible. Conclusion. Arthroscopic treatment of osteochondral lesions of the talus gives medium term improvement in the majority of patients, but it appears that results deteriorate with time. Recurrence of symptoms sufficient to require further surgical intervention occurred in half the patients studied

Aims. To investigate (1) The relationship between macroscopic grading and durability of cartilage repair following collagen-covered autologous chondrocyte implantation (ACI-C) in the knee; (2) The influence of histology on durability of cartilage repair; (3) The relationship between macroscopic appearance and histology of repair tissue. Patients and methods. The modified Cincinnati scores (MCRS) of eighty-six patients were evaluated prospectively at one year and at the latest follow-up (mean follow-up = 4.7yrs. Range = 4 to 7 years). Needle biopsies of their cartilage repair site were stained with Haematoxylin and Eosin and some with Safranin O and the neo-cartilage was graded as hyaline-like (n=32, 37.2%), mixed fibro-hyaline (n=19, 22%) and fibro-cartilagenous tissue (n=35, 40.7%). Macroscopic grading of the repair tissue using the international cartilage repair society grading system (ICRS) was available for fifty-six patients in the study cohort. Statistical analyses were performed to investigate the significance of histology and ICRS grading on MCRS at 1 year and at the latest follow-up. Results. The MCRS of all three histology groups were comparable at one year evaluation (p=0.34). However, their clinical scores at the latest follow-up (mean = 4.7years) showed a significantly superior result for those with hyaline-like repair tissue when compared to those with mixed fibro-hyaline and fibro-cartilagenous repair (p=0.05). There was no correlation between the ICRS macroscopic grading and MCRS (clinical) grading either at one year (p=0.12) or at the latest follow-up (p=0.16). Also, the ICRS grading of the repair tissue did not correlate with its histological type (p=0.12). Conclusion. We conclude that any form of cartilage repair gave a good clinical outcome at one year. At four years and beyond, hyaline-like repair tissue was associated with a more favourable clinical outcome. Macroscopic evaluation using the ICRS grading system does not reflect the clinical outcome or its durability or the histological type of repair tissue