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

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

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

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

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

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. 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

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

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

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

The results for autologous chondrocyte implantation (ACI) in the treatment of osteochondral defects in the knee are encouraging. At present, two techniques have been described to retain the chondrocyte suspension within the defect. The first involves using a periosteal flap harvested from the distal femur and the second involves using a type I/III collagen membrane. To the authors' knowledge there are no comparative studies of these two techniques in the current literature. A total of 68 patients with a mean age of 30.52 years (range 15 to 52 years) with symptomatic articular cartilage defects were randomised to have either ACI with a periosteal cover (33 patients) or ACI with a type I/III collagen cover (35 patients). The mean defect size was 4.54 cm. 2. (range 1 to 12 cm. 2. ). All patients were followed up at 24 months. A functional assessment using the Modified Cincinnati score showed that 74% of patients had a good or excellent result following the ACI with collagen cover compared with 67% after the ACI with periosteum cover at 2 years (p>0.05). Arthroscopy at 1 year also demonstrated similar results for both techniques. However, 36.4% of the periosteum covered grafts required shaving for hypertrophy compared with 1 patient for the collagen covered technique. This prospective, randomised study has shown no statistical difference between the clinical outcome of ACI with a periosteal cover versus ACI with a collagen cover at 2 years. A significant number of patients who had the ACI with periosteum technique required shaving of a hypertrophied graft within the first year of surgery. We conclude that there is no advantage in using periosteum as a cover for retaining the chondrocytes within an osteochondral defect; as a result we advocate the use of an alternative cover such as a porcine-derived, type I/III collagen membrane

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