Mats Brittberg

Treatment of Deep Cartilage Defects in the Knee with Autologous Chondrocyte Transplantation

BACKGROUND Full-thickness defects of articular cartilage in the knee have a poor capacity for repair. They may progress to osteoarthritis and require total knee replacement. We performed autologous chondrocyte transplantation in 23 people with deep cartilage defects in the knee. METHODS The patients ranged in age from 14 to 48 years and had full-thickness cartilage defects that ranged in size from 1.6 to 6.5 cm2. Healthy chondrocytes obtained from an uninvolved area of the injured knee during arthroscopy were isolated and cultured in the laboratory for 14 to 21 days. The cultured chondrocytes were then injected into the area of the defect. The defect was covered with a sutured periosteal flap taken from the proximal medial tibia. Evaluation included clinical examination according to explicit criteria and arthroscopic examination with a biopsy of the transplantation site. RESULTS Patients were followed for 16 to 66 months (mean, 39). Initially, the transplants eliminated knee locking and reduced pain and swelling in all patients. After three months, arthroscopy showed that the transplants were level with the surrounding tissue and spongy when probed, with visible borders. A second arthroscopic examination showed that in many instances the transplants had the same macroscopic appearance as they had earlier but were firmer when probed and similar in appearance to the surrounding cartilage. Two years after transplantation, 14 of the 16 patients with femoral condylar transplants had good-to-excellent results. Two patients required a second operation because of severe central wear in the transplants, with locking and pain. A mean of 36 months after transplantation, the results were excellent or good in two of the seven patients with patellar transplants, fair in three, and poor in two; two patients required a second operation because of severe chondromalacia. Biopsies showed that 11 of the 15 femoral transplants and 1 of the 7 patellar transplants had the appearance of hyaline cartilage. CONCLUSION Cultured autologous chondrocytes can be used to repair deep cartilage defects in the femorotibial articular surface of the knee joint.

Two- to 9-year outcome after autologous chondrocyte transplantation of the knee.

Autologous cultured chondrocyte transplantation was introduced in Sweden in 1987 for the treatment of large (1.5-12.0 cm2) full thickness chondral defects of the knee. The clinical, arthroscopic, and histologic results from the first 101 patients treated using this technique are reported in this study. Patients were assessed retrospectively using three types of endpoints: patient and physician derived clinical rating scales (five validated and two new); arthroscopic assessment of cartilage fill, integration, and surface hardness; and standard histochemical techniques. Ninety-four patients with 2- to 9-years followup were evaluable. Good to excellent clinical results were seen in individual groups as follows: isolated femoral condyle (92%), multiple lesions (67%), osteochondritis dissecans (89%), patella (65%), and femoral condyle with anterior cruciate ligament repair (75%). Arthroscopic findings in 53 evaluated patients showed good repair tissue fill, good adherence to underlying bone, seamless integration with adjacent cartilage, and hardness close to that of the adjacent tissue. Hypertrophic response of the periosteum or graft or both was identified in 26 arthroscopies; seven were symptomatic and resolved after arthroscopic trimming. Graft failure occurred in seven (four of the first 23 and three of the next 78) patients. Histologic analysis of 37 biopsy specimens showed a correlation between hyalinelike tissue (hyaline matrix staining positive for Type II collagen and lacking a fibrous component) and good to excellent clinical results. The good clinical outcomes of autologous chondrocyte transplantation in this study are encouraging, and clinical trials are being done to assess the outcomes versus traditional fibrocartilage repair techniques.

Autologous Chondrocyte Transplantation Biomechanics and Long-Term Durability

We evaluated the durability of autologous chondrocyte transplantation grafts in 61 patients treated for isolated cartilage defects on the femoral condyle or the patella and followed up for a mean of 7.4 years (range, 5 to 11). Durability was determined by comparing the clinical status at the long-term follow-up with that found 2 years after the transplantation. After 2 years, 50 of the 61 patients had good or excellent clinical results, and 51 of 61 had good or excellent results at 5 to 11 years later. Grafted areas from 11 of the patients were evaluated with an electromechanical indentation probe during a second-look arthroscopy procedure (mean follow-up, 54.3 months; range, 33 to 84); stiffness measurements were 90% or more of those of normal cartilage in eight patients. Eight of twelve 2-mm biopsy samples taken from these patients showed hyaline characteristics with safranin O staining and a homogeneous appearance in polarized light. Three fibrous and eight hyaline biopsy specimens stained positive to aggrecan and to cartilage oligomeric matrix protein. Hyaline-like specimens stained positive for type II collagen, and fibrous, for type I collagen. Autologous chondrocyte transplantation for the treatment of articular cartilage injuries has a durable outcome for as long as 11 years.

Evaluation of cartilage injuries and repair.

Articular cartilage injuries ( Fig. 1 ) are common findings during arthroscopy 1 and diagnostic imaging of the joints 2,3. While there are many techniques for the treatment of cartilage injuries, not enough is known about which lesions need treatment or about the proper treatment modality for a particular lesion. More objective data regarding cartilage injuries and more accurate methods to evaluate the operative outcomes are required, especially since new procedures are becoming increasingly expensive. There are many published reports on the outcomes of total joint replacement based on clinical scores and radiographic evaluations. However, it has been quite difficult to interpret the reported results of the repair of focal cartilage defects as there is no universally accepted system to describe the lesions, the repair tissue, or the clinical symptoms for this category of patients. More studies on clinical articular cartilage resurfacing will appear in the future, making it important to develop common evaluation measurement tools and standards. The International Cartilage Repair Society (ICRS) was founded in 1997 and has been interested in developing a standardization system for the evaluation of cartilage injury and repair 4,5. A working group of the ICRS was established with the aim of developing a common, easy system for clinical and arthroscopic evaluation ( Table I ). Shortly thereafter, the Articular Cartilage Imaging Committee of the ICRS was created to assess the existing clinical imaging techniques, to recommend specific magnetic resonance imaging techniques for the assessment of articular cartilage 6, and to develop a standardized magnetic resonance imaging evaluation system for native and repaired cartilage ( Table I ). A state-of-the-art system for clinical cartilage evaluation and imaging assessment is presented below. Fig. 1: A cartilage lesion on a femoral condyle, extending deep down to bone. Note that some calcified …

Treatment of osteochondritis dissecans of the knee with autologous chondrocyte transplantation results at two to ten years

Background: Osteochondritis dissecans of the knee is a challenging clinical problem. We previously reported on the early successful results of autologous chondrocyte transplantation for the treatment of focal cartilage defects. The purpose of the present study was to assess the intermediate to long-term results of this technique in a large group of patients with osteochondritis dissecans.Methods: Fifty-eight patients with radiographically documented osteochondritis dissecans of the knee underwent treatment with autologous chondrocyte transplantation between 1987 and 2000 and were assessed clinically with use of standard rating scales. Twenty-two patients consented to arthroscopic second-look evaluation of graft integrity.Results: The mean age of the patients at the time of autologous chondrocyte transplantation was 26.4 years (range, fourteen to fifty-two years). Seven patients were less than eighteen years old. Thirty-five patients (60%) had juvenile-onset disease, and forty-eight patients (83%) had had a mean of 2.1 prior operations. The defect was located on the medial femoral condyle in thirty-nine patients and on the lateral femoral condyle in nineteen. The mean lesion size was 5.7 cm 2 (range, 1.5 to 12.0 cm 2 ), and the mean defect depth was 7.8 mm (range, 4 to 15 mm). After a mean duration of follow-up of 5.6 years, 91% of the patients had a good or excellent overall rating on the basis of a clinician evaluation and 93% had improvement on a patient self-assessment questionnaire. The Tegner-Wallgren, Lysholm, and Brittberg-Peterson VAS scores were all improved. The macroscopic quality of graft integrity averaged 11.2 on a 12-point scale, with only one graft having a score of <9 points. Two patients had a failure of treatment in the early postoperative period. Only one patient who had had a good or excellent rating at two years had a decline in clinical status at the time of the latest follow-up.Conclusions: Treatment of osteochondritis dissecans lesions of the knee with autologous chondrocyte transplantation produces an integrated repair tissue with a successful clinical result in >90% of patients. We recommend the wider use of autologous chondrocyte transplantation for this condition.

Rabbit articular cartilage defects treated with autologous cultured chondrocytes.

Adult New Zealand rabbits were used to transplant autologously harvested and in vitro cultured chondrocytes into patellar chondral lesions that had been made previously and were 3 mm in diameter, extending down to the calcified zone. Healing of the defects was assessed by gross examination, light microscope, and histological-histochemical scoring at 8, 12, and 52 weeks. Chondrocyte transplantation significantly increased the amount of newly formed repair tissue compared to that found in control knees in which the lesion was solely covered by a periosteal flap. In another experiment, carbon fiber pads seeded with chondrocytes were used as scaffolds, and repair significantly increased at both 12 and 52 weeks compared to knees in which scaffolds without chondrocytes were implanted. The histologic quality scores of the repair tissue were significantly better in all knees in which defects were treated with chondrocytes compared to knees treated with periosteum alone and better at 52 weeks compared to knees in which defects were treated with carbon scaffolds seeded with chondrocytes. The repair tissue, however, tended to incomplete the bonding to adjacent cartilage. This study shows that isolated autologous articular chondrocytes that have been expanded for 2 weeks in vitro can stimulate the healing phase of chondral lesions. A gradual maturation of the hyalinelike repair with a more pronounced columnarization was noted as late as 1 year after surgery.

Autologous Chondrocyte Implantation: A Long-term Follow-up

Background: The medium-term results of autologous chondrocyte implantation (ACI) have shown good to excellent outcomes for the majority of patients. However, no long-term results 10 to 20 years after the surgery have been reported. Hypothesis: Autologous chondrocyte implantation provides a durable solution to the treatment of full-thickness cartilage lesions of the knee, maintaining good clinical results even 10 to 20 years after implantation. Study Design: Case series; Level of evidence, 4. Methods: In this uncontrolled study, questionnaires with the Lysholm, Tegner-Wallgren, Brittberg-Peterson, modified Cincinnati (Noyes), and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores were sent to 341 patients. Preoperative Lysholm, Tegner-Wallgren, and Brittberg-Peterson scores were also retrieved when possible from patients’ files. The patients were asked to grade their status during the past 10 years as better, worse, or unchanged. Finally, they were asked if they would do the operation again. Results: There were 224 of 341 patients who replied to our posted questionnaires and were assessed. The mean cartilage lesion size was 5.3 cm2. Ten to 20 years after the implantation (mean, 12.8 years), 74% of the patients reported their status as better or the same as the previous years. There were 92% who were satisfied and would have the ACI again. The Lysholm, Tegner-Wallgren, and Brittberg-Peterson scores were improved compared with the preoperative values. The average Lysholm score improved from 60.3 preoperatively to 69.5 postoperatively, the Tegner from 7.2 to 8.2, and the Brittberg-Peterson from 59.4 to 40.9. At the final measurement, the KOOS score was on average 74.8 for pain, 63 for symptoms, 81 for activities of daily living (ADL), 41.5 for sports, and 49.3 for quality of life (QOL). The average Noyes score was 5.4. Patients with bipolar lesions had a worse final outcome than patients with multiple unipolar lesions. The presence of meniscal injuries before ACI or history of bone marrow procedures before the implantation did not appear to affect the final outcomes. The age at the time of the operation or the size of lesion did not seem to correlate with the final outcome. Conclusion: Autologous chondrocyte implantation has emerged as an effective and durable solution for the treatment of large full-thickness cartilage and osteochondral lesions of the knee joint. Our study suggests that the clinical and functional outcomes remain high even 10 to 20 years after the implantation.

Autologous chondrocytes used for articular cartilage repair: an update.

Articular cartilage in adults has a poor ability to self-repair after a substantial injury; however, it is not known whether there is a cartilage resurfacing technique superior to the existing techniques. It is not satisfactory that at the beginning of the new millennium, there still is a lack of randomized studies comparing different cartilage repair techniques and there still is little knowledge of the natural course of a cartilaginous lesion. To date, various articular cartilage resurfacing techniques have the potential to improve the repair of cartilage defects and reduce the patients disability. One such cartilage repair technique is autologous chondrocyte transplantation combined with a periosteal graft. Since the first patient was operated on in 1987, much interest in cartilage repair and cell engineering has emerged. The experience with autologous chondrocyte transplantation during the past 13 years with in vitro chondrocyte expansion, cartilage harvest, and postoperative biopsy technique is discussed, and the latest followup of 213 consecutive patients in different subgroups with 2 to 10 years followup is presented. The technique gives stable long-term results with a high percentage of good to excellent results (84%-90%) in patients with different types of single femoral condyle lesions, whereas patients with other types of lesions have a lower degree of success (mean, 74%).

The subchondral bone in articular cartilage repair: current problems in the surgical management.

As the understanding of interactions between articular cartilage and subchondral bone continues to evolve, increased attention is being directed at treatment options for the entire osteochondral unit, rather than focusing on the articular surface only. It is becoming apparent that without support from an intact subchondral bed, any treatment of the surface chondral lesion is likely to fail. This article reviews issues affecting the entire osteochondral unit, such as subchondral changes after marrow-stimulation techniques and meniscectomy or large osteochondral defects created by prosthetic resurfacing techniques. Also discussed are surgical techniques designed to address these issues, including the use of osteochondral allografts, autologous bone grafting, next generation cell-based implants, as well as strategies after failed subchondral repair and problems specific to the ankle joint. Lastly, since this area remains in constant evolution, the requirements for prospective studies needed to evaluate these emerging technologies will be reviewed.

Cell Carriers as the Next Generation of Cell Therapy for Cartilage Repair: A Review of the Matrix-Induced Autologous Chondrocyte Implantation Procedure

Background: Since the first patient was implanted with autologous cultured chondrocytes more than 20 years ago, new variations of cell therapies for cartilage repair have appeared. Autologous chondrocyte implantation, a first-generation cell therapy, uses suspended autologous cultured chondrocytes in combination with a periosteal patch. Collagen-covered autologous cultured chondrocyte implantation, a second-generation cell therapy, uses suspended cultured chondrocytes with a collagen type I/III membrane. Today’s demand for transarthroscopic procedures has resulted in the development of third-generation cell therapies that deliver autologous cultured chondrocytes using cell carriers or cell-seeded scaffolds. Purpose: To review the current evidence of the matrix-induced autologous chondrocyte implantation procedure, the most widely used carrier system to date. Also discussed are the characteristics of type I/III collagen membranes, behavior of cells associated with the membrane, surgical technique, rehabilitation, clinical outcomes, and quality of repair tissue. Study Design: Systematic review. Methods: Relevant publications were identified by searching Medline from its inception (1949) to December 2007; peer-reviewed publications of preclinical and clinical cell behavior, manufacturing process, surgical technique, and rehabilitation protocols were identified. Preclinical and clinical studies were included if they contained primary data and used a type I/III collagen membrane. Results: Data from these studies demonstrate that patients treated with matrix-induced autologous chondrocyte implantation have an overall improvement in clinical outcomes. Reduced visual analog scale pain levels (range, 1.7-5.32 points) and improvements in the modified Cincinnati (range, 3.8-34.2 points), Lysholm-Gillquist (range, 23.09-47.6 points), Tegner-Lysholm (range, 1.39-3.9 points), and International Knee Documentation Classification scale (P <.05) were observed. Patients had good-quality (hyaline-like) repair tissue as assessed by arthroscopic evaluation (including International Cartilage Repair Society score), magnetic resonance imaging, and histology, as well as a low incidence of postoperative complications. Conclusion: The findings suggest that matrix-induced autologous chondrocyte implantation is a promising third-generation cell therapy for the repair of symptomatic, full-thickness articular cartilage defects.