Evidence-based status of second- and third-generation autologous chondrocyte implantation over first generation: a systematic review of level I and II studies

Matrix-Induced Autologous Chondrocyte Implantation versus Multipotent Stem Cells for the Treatment of Large Patellofemoral Chondral Lesions: A Nonrandomized Prospective Trial

OBJECTIVE

To compare the outcome of matrix-induced autologous chondrocyte implantation (MACI) and bone marrow aspirate concentrate (BMAC)-derived multipotent stem cells (MSCs) implantation in patellofemoral chondral lesions, using the same HYAFF11 scaffold.

METHODS

From January 2005 to December 2010, 37 patients with patellofemoral chondral lesions were prospectively followed up, for a minimum of 3 years; 19 of these patients were treated with MACI and 18 with BMAC. Radiographs, magnetic resonance imaging, and clinical scores (International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score, visual analog scale, and Tegner) were collected preoperatively, at 2-year and final follow-up. Five patients of MACI and 6 of the BMAC group underwent second-look arthroscopy; 4 patients of each group consented to a concomitant biopsy.

RESULTS

No adverse reactions or postoperative infections were noted. Baseline characteristics were similar in both groups (P > 0.05). Both groups showed significant improvement in all scores, from preoperative to final follow-up (P = 0.001), but there was no significant difference in improvement between the 2 groups, except for the IKDC subjective score (P = 0.015), which favored the BMAC group. Deterioration in MACI and improvement in BMAC group scores were noticed, from 2-year to final follow-up, but was nonsignificant. MACI patients with trochlear lesions showed better results than patellar lesions, while location was not a prognostic factor in the BMAC group. MRI showed complete filling of the defects in 76% of patients in MACI and 81% of patients in BMAC, and histological analysis revealed hyaline-like features.

CONCLUSION

Both techniques are viable and effective for large patellofemoral chondral lesions at minimum 3-year follow-up.

Next Generation Mesenchymal Stem Cell (MSC)-Based Cartilage Repair Using Scaffold-Free Tissue Engineered Constructs Generated with Synovial Mesenchymal Stem Cells

Because of its limited healing capacity, treatments for articular cartilage injuries are still challenging. Since the first report by Brittberg, autologous chondrocyte implantation has been extensively studied. Recently, as an alternative for chondrocyte-based therapy, mesenchymal stem cell-based therapy has received considerable research attention because of the relative ease in handling for tissue harvest, and subsequent cell expansion and differentiation. This review summarizes latest development of stem cell therapies in cartilage repair with special attention to scaffold-free approaches.

Microfracture produces inferior outcomes to other cartilage repair techniques in chondral injuries in the paediatric knee

INTRODUCTION

Chondral injuries are becoming increasingly common in the paediatric knee. First line surgical therapy is usually microfracture (MF), but the emergence of alternative techniques raises the question of what is the optimal treatment in paediatric patients.

SOURCES OF DATA

A comprehensive search of PubMed, OVID, Web of Science, SportDiscus and Cochrane databases was performed using the key words 'autologous chondrocyte implantation, MF, mosaicplasty, juvenile, paediatric'.

AREAS OF AGREEMENT

Each technique demonstrated a significant post-surgical improvement in clinical outcome scores. However, MF demonstrated poorer outcomes in larger lesions (>3 cm(2)) and shorter durability.

AREA OF CONTROVERSY

The quality of the available literature is poor, and there is a lack of comparative trials.

GROWING POINTS

The impact of defect characteristics, mechanism of injury and concomitant surgeries should be investigated.

AREAS TIMELY FOR DEVELOPING RESEARCH

Appropriately powered randomized controlled trials with suitably long follow up and condition-specific outcome measures should compare different techniques against each other and placebo.

Arthroscopic airbrush assisted cell implantation for cartilage repair in the knee: a controlled laboratory and human cadaveric study

OBJECTIVE

The objective of this study was to investigate the feasibility of arthroscopic airbrush assisted cartilage repair.

METHODS

An airbrush device (Baxter) was used to spray both human expanded osteoarthritic chondrocytes and choncrocytes with their pericellular matrix (chondrons) at 1 × 10(6) cells/ml fibrin glue (Tissucol, Baxter) in vitro. Depth-dependent cell viability was assessed for both methods with confocal microscopy. Constructs were cultured for 21 days to assess matrix production. A controlled human cadaveric study (n = 8) was performed to test the feasibility of the procedure in which defects were filled with either arthroscopic airbrushing or needle extrusion. All knees were subjected to 60 min of continuous passive motion and scored on outline attachment and defect filling.

RESULTS

Spraying both chondrocytes and chondrons in fibrin glue resulted in a homogenous cell distribution throughout the scaffold. No difference in viability or matrix production between application methods was found nor between chondrons and chondrocytes. The cadaveric study revealed that airbrushing was highly feasible, and that defect filling through needle extrusion was more difficult to perform based on fibrin glue adhesion and gravity-induced seepage. Defect outline and coverage scores were consistently higher for extrusion, albeit not statistically significant.

CONCLUSION

Both chondrons and chondrocytes can be evenly distributed in a sprayed fibrin glue scaffold without affecting viability while supporting matrix production. The airbrush technology is feasible, easier to perform than needle extrusion and allows for reproducible arthroscopic filling of cartilage defects.

Matrix-induced autologous chondrocyte implantation for the treatment of chondral defects of the knees in Chinese patients

Articular cartilage injury is the most common type of damage seen in clinical orthopedic practice. The matrix-induced autologous chondrocyte implant (MACI) was developed to repair articular cartilage with an advance on the autologous chondrocyte implant procedure. This study aimed to evaluate whether MACI is a safe and efficacious cartilage repair treatment for patients with knee cartilage lesions. The primary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) domains and magnetic resonance imaging (MRI) results, compared between baseline and postoperative months 3, 6, 12, and 24. A total of 15 patients (20 knees), with an average age of 33.9 years, had a mean defect size of 4.01 cm(2). By 6-month follow-up, KOOS results demonstrated significant improvements in symptoms and knee-related quality of life. MRI showed significant improvements in four individual graft scoring parameters at 24 months postoperatively. At 24 months, 90% of MACI grafts had filled completely and 10% had good-to-excellent filling of the chondral defect. Most (95%) of the MACI grafts were isointense and 5% were slightly hyperintense. Histologic evaluation at 15 and 24 months showed predominantly hyaline cartilage in newly generated tissue. There were no postoperative complications in any patients and no adverse events related to the MACI operation. This 2-year study has confirmed that MACI is safe and effective with the advantages of a simple technique and significant clinical improvements. Further functional and mechanistic studies with longer follow-up are needed to validate the efficacy and safety of MACI in patients with articular cartilage injuries.

Cartilage Repair With Autologous Bone Marrow Mesenchymal Stem Cell Transplantation: Review of Preclinical and Clinical Studies

Clinical trials of various procedures, including bone marrow stimulation, mosaicplasty, and autologous chondrocyte implantation, have been explored to treat articular cartilage defects. However, all of them have some demerits. We focused on autologous culture-expanded bone marrow mesenchymal stem cells (BMSC), which can proliferate without losing their capacity for differentiation. First, we transplanted BMSC into the defective articular cartilage of rabbit and succeeded in regenerating osteochondral tissue. We then applied this transplantation in humans. Our previous reports showed that treatment with BMSC relieves the clinical symptoms of chondral defects in the knee and elbow joint. We investigated the efficacy of BMSC for osteoarthritic knee treated with high tibial osteotomy, by comparing 12 BMSC-transplanted patients with 12 cell-free patients. At 16-month follow-up, although the difference in clinical improvement between both groups was not significant, the arthroscopic and histological grading score was better in the cell-transplanted group. At the over 10-year follow-up, Hospital for Special Surgery knee scores improved to 76 and 73 in the BMSC-transplanted and cell-free groups, respectively, which were better than preoperative scores. Additionally, neither tumors nor infections were observed in all patients, and in the clinical study, we have never observed hypertrophy of repaired tissue, thereby guaranteeing the clinical safety of this therapy. Although we have never observed calcification above the tidemark in rabbit model and human histologically, the repair cartilage was not completely hyaline cartilage. To elucidate the optimum conditions for cell therapy, other stem cells, culture conditions, growth factors, and gene transfection methods should be explored.

Chondral Injury in Patellofemoral Instability

OBJECTIVE

Patellofemoral instability is common and affects a predominantly young age group. Chondral injury occurs in up to 95%, and includes osteochondral fractures and loose bodies acutely and secondary degenerative changes in recurrent cases. Biomechanical abnormalities, such as trochlear dysplasia, patella alta, and increased tibial tuberosity-trochlear groove distance, predispose to both recurrent dislocations and patellofemoral arthrosis.

DESIGN

In this article, we review the mechanisms of chondral injury in patellofemoral instability, diagnostic modalities, the distribution of lesions seen in acute and episodic dislocation, and treatments for articular cartilage lesions of the patellofemoral joint.

RESULTS

Little specific evidence exists for cartilage treatments in patellofemoral instability. In general, the results of reparative and restorative procedures in the patellofemoral joint are inferior to those observed in other compartments of the knee.

CONCLUSION

Given the increased severity of chondral lesions and progression to osteoarthritis seen with recurrent dislocations, careful consideration should be given to early stabilisation in patients with predisposing factors.

First-generation versus second-generation autologous chondrocyte implantation for treatment of cartilage defects of the knee: a matched-pair analysis on long-term clinical outcome

PURPOSE

Since the introduction of autologous chondrocyte implantation (ACI) for the treatment of cartilage defects, the initial technique has undergone several modifications. Whereas an autologous periosteum flap was used for defect coverage in first generation ACI, a standardized collagen membrane was utilized in second generation ACI. To date, however, no study has proven the superiority of this modification in terms of long-term clinical outcome. The purpose of this matched-pair analysis was therefore to compare the clinical long-term outcome of first and second generation ACI with a minimum follow-up of ten years.

METHODS

A total of 23 patients treated with second generation ACI for isolated cartilage defects of the knee were evaluated after a minimum follow-up of ten years using Lysholm and IKDC scores. The results of these patients were compared to those of 23 matched patients treated with first generation ACI. Pair wise matching was performed by defect location, patient age, and defect size.

RESULTS

While all patient characteristics such as age (31.7 years SD 6.9 vs. 31.4 years SD 7.8), defect size (5.1 cm² SD 2.3 vs. 4.9 cm² SD 1.5), and follow-up time (10.7 months SD 1.0 vs. 10.5 months SD 0.6) were distributed homogenously in both treatment groups, significant better Lysholm (82.7 SD 9.9 versus 75.6 SD 11.8; p = 0.031) and IKDC scores (76.4 SD 12.8 versus 68.0 SD 12.0, p = 0.023) were found in the group of patients treated with second generation ACI compared to those treated with first generation ACI. In both groups, four patients (17.4%) received surgical reintervention during follow-up.

CONCLUSIONS

The use of a collagen membrane in combination with autologous chondrocytes (second generation ACI) leads to superior clinical long-term outcome compared to first generation ACI. Based on these results, second generation ACI should be preferred over first generation ACI.

Management of patellofemoral chondral injuries

Treatment of patellofemoral chondral defects is fraught with difficulty because of the generally inferior outcomes and significant biomechanical complexity of the joint. Noyes and Barber-Westin38 performed a systematic review of large (>4 cm2) patellofemoral ACI (11 studies), PFA (5 studies), and osteochondral allografting (2 studies) in patients younger than 50 years. Respectively, failures or poor outcomes were noted in 8% to 60% after ACI, 22% after PFA, and 53% after osteochondral allograft treatment. As noted in the outcome reviews earlier, unacceptable complication and reoperation rates were reported from all 3 procedures, and it was concluded that each operation had unpredictable results for this patient demographic. This study highlights the importance of strict indications and working to address all concomitant diseases to decrease revision rate. Outcomes are most predictable in young patients with low BMI and unipolar defects lower than 4 cm2.

Evidence-based status of osteochondral cylinder transfer techniques: a systematic review of level I and II studies

PURPOSE

Our purpose was to examine the Level I and II evidence for the use of osteochondral cylinder transfer technique (OCT) for cartilage repair.

METHODS

A literature search was carried out for Level I and II evidence studies on cartilage repair using the PubMed database. All the studies that involved OCT were identified. Only Level I and II studies that compared OCT to other modalities of treatment such as microfracture (MF) and autologous chondrocyte implantation (ACI) were selected.

RESULTS

A total of 8 studies matched the selection criteria with 2 Level I and 6 Level II studies. Four studies compared OCT with MF, 3 compared OCT with ACI, and one compared all 3 techniques. Of 3 studies, 4 came from a single center. Mean age of patients ranged from 24 to 33 years, and mean follow-up ranged from 9 to 124 months. The studies from the single center showed superior results from OCT over MF, especially in younger patients, with one study having long-term follow-up of 10 years. They also showed an earlier return to sports. The size of the lesions were small (average < 3 cm(2)). The 4 other independent studies did not show any difference between OCT and ACI, with one study showing inferior outcome in the OCT group. Magnetic resonance imaging (MRI) showed good osseous integration of the osteochondral plugs to the subchondral bone. Histologic examination showed that there was hyaline cartilage in the transplanted osteochondral plugs but no hyaline cartilage between the plugs.

CONCLUSIONS

From the studies of a single center, OCT had an advantage over MF in younger patients with small chondral lesions. Comparison of outcomes between OCT and ACI showed no significant difference in 2 studies and contrasting results in another 2 studies. There was insufficient evidence for long-term results for OCT.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.