Long-term clinical results and MRI changes after autologous chondrocyte implantation in the knee of young and active middle aged patients

Sex does not influence the long-term outcome of matrix-assisted autologous chondrocyte transplantation

PURPOSE

Regenerative techniques for articular cartilage lesions demonstrated heterogeneous clinical results. Several factors may influence the outcome, with sex being one of the most debated. This study aimed at quantifying the long-term influence of sex on the clinical outcome obtained with a regenerative procedure for knee chondral lesions.

METHODS

Matrix-assisted autologous chondrocyte transplantation (MACT) was used to treat 235 knees which were prospectively evaluated with the International Knee Documentation Committee (IKDC), EuroQol visual analogue scale, and Tegner scores at 14-year mean follow-up. A multilevel analysis was performed with the IKDC subjective scores standardised according to the age/sex category of each patient and/or the selection of a match-paired subgroup to compare homogeneous men and women patients.

RESULTS

At 14 years, men and women showed a failure rate of 10.7% and 28.8%, respectively (p < 0.0005). An overall improvement was observed in both sexes. Women had more patellar lesions and men more condylar lesions (p = 0.001), and the latter also presented a higher preinjury activity level (p < 0.0005). Men had significantly higher IKDC subjective scores at all follow-ups (at 14 years: 77.2 ± 18.9 vs. 62.8 ± 23.1; p < 0.0005). However, the analysis of homogeneous match-paired populations of men and women, with standardised IKDC subjective scores, showed no differences between men and women (at 14 years: -1.6 ± 1.7 vs. -1.9 ± 1.6).

CONCLUSION

Men and women treated with MACT for knee chondral lesions presented a significant improvement and stable long-term results. When both sexes are compared with homogeneous match-paired groups, they have similar results over time. However, women present more often unfavourable lesion patterns, which proved more challenging in terms of long-term outcome after MACT.

LEVEL OF EVIDENCE

Level II.

Matrix-Assisted Autologous Chondrocyte Transplantation for the Treatment of Patellofemoral Chondral Lesions: Long-term Results at a Minimum 15-Year Follow-up

BACKGROUND

A few studies have documented the long-term results of chondrocyte-based procedures for the treatment of patellofemoral cartilage lesions, but specific results are lacking after matrix-assisted autologous chondrocyte transplantation (MACT) for patellar and trochlear lesions.

PURPOSE

To document the clinical results of MACT for the treatment of patellar and trochlear chondral defects at long-term follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 44 patients were prospectively evaluated after MACT for patellofemoral lesions. There were 24 patients affected by patellar lesions, 16 by trochlear lesions, and 4 with both patellar and trochlear defects. Clinical outcomes were analyzed using the International Knee Documentation Committee (IKDC) subjective form, EuroQol visual analog scale, and Tegner score for sport activity level before surgery and at follow-up time points of 5, 10, and a minimum of 15 years (mean final follow-up, 17.6 ± 1.6 years). A Kaplan-Meier survival analysis was performed to examine the survival to failure. Failure was defined as the need for a second surgery because of the persistence of symptoms related to the primary defect.

RESULTS

An overall significant improvement was documented from baseline to the last follow-up. The IKDC subjective score improved in the trochlear group from 41.0 ± 13.3 at baseline to 83.9 ± 21.6 at 5 years (P < .005), remaining stable up to the final follow-up (81.3 ± 20.5). In the patellar group, the IKDC subjective score improved from 36.1 ± 14.4 at baseline to 72.3 ± 17.5 at 5 years (P < .005), remaining stable up to the final follow-up (62.0 ± 20.3). Patients with trochlear lesions presented higher IKDC subjective scores compared with those with patellar lesions at 5 (P = .029), 10 (P = .023), and ≥15 years (P = .006) of follow-up. Similar trends were documented for the Tegner score, while no differences were documented for the EuroQol visual analog scale score between patellar and trochlear lesions. There were 4 failures (9.1%) during the follow-up period. The Kaplan-Meier survival analysis did not show statistically significant differences between trochlear and patellar lesions.

CONCLUSION

This hyaluronic acid-based MACT technique offered positive and durable clinical outcomes with a low failure rate at long-term follow-up in patients affected by patellofemoral cartilage lesions. However, trochlear and patellar lesions demonstrated a notable difference in terms of clinical findings and sport activity level, with significantly higher results for patients with trochlear lesions but less satisfactory outcomes for patients with patellar lesions.

Chondrocyte Isolation from Loose Bodies-An Option for Reducing Donor Site Morbidity for Autologous Chondrocyte Implantation

Loose bodies (LBs) from patients with osteochondritis dissecans (OCD) are usually removed and discarded during surgical treatment of the defect. In this study, we address the question of whether these LBs contain sufficient viable and functional chondrocytes that could serve as a source for autologous chondrocyte implantation (ACI) and how the required prolonged in vitro expansion affects their phenotype. Chondrocytes were isolated from LBs of 18 patients and compared with control chondrocyte from non-weight-bearing joint regions (n = 7) and bone marrow mesenchymal stromal cells (BMSCs, n = 6) obtained during primary arthroplasty. No significant differences in the initial cell yield per isolation and the expression of the chondrocyte progenitor cell markers CD44 + /CD146+ were found between chondrocyte populations from LBs (LB-CH) and control patients (Ctrl-CH). During long-term expansion, LB-CH exhibited comparable viability and proliferation rates to control cells and no ultimate cell cycle arrest was observed within 12 passages respectively 15.3 ± 1.1 mean cumulative populations doublings (CPD). The chondrogenic differentiation potential was comparable between LB-CH and Ctrl-CH, but both groups showed a significantly higher ability to form a hyaline cartilage matrix in vitro than BMSC. Our data suggest that LBs are a promising cell source for obtaining qualitatively and quantitatively suitable chondrocytes for therapeutic applications, thereby circumventing donor site morbidity as a consequence of the biopsies required for the current ACI procedure.

Predictive analysis of lower limb fractures in the orthopedic complex operative unit using artificial intelligence: the case study of AOU Ruggi

The length of stay (LOS) in hospital is one of the main parameters for evaluating the management of a health facility, of its departments in relation to the different specializations. Healthcare costs are in fact closely linked to this parameter as well as the profit margin. In the orthopedic field, the provision of this parameter is increasingly complex and of fundamental importance in order to be able to evaluate the planning of resources, the waiting times for any scheduled interventions and the management of the department and related surgical interventions. The purpose of this work is to predict and evaluate the LOS value using machine learning methods and applying multiple linear regression, starting from clinical data of patients hospitalized with lower limb fractures. The data were collected at the "San Giovanni di Dio e Ruggi d'Aragona" hospital in Salerno (Italy).

Prognostic factors for the management of chondral defects of the knee and ankle joint: a systematic review

Purpose

Different surgical techniques to manage cartilage defects are available, including microfracture (MFx), autologous chondrocyte implantation (ACI), osteoarticular auto- or allograft transplantation (OAT), autologous matrix-induced chondrogenesis (AMIC). This study investigated the patient-related prognostic factors on the clinical outcomes of surgically treated knee and ankle cartilage defects.

Methods

This study followed the PRISMA statement. In May 2022, the following databases were accessed: PubMed, Google Scholar, Embase, and Scopus. All the studies investigating the outcomes of surgical management for knee and/or talus chondral defects were accessed. Only studies performing mesenchymal stem cells transplantation, OAT, MFx, ACI, and AMIC were considered. A multiple linear model regression analysis through the Pearson Product–Moment Correlation Coefficient was used.

Results

Data from 184 articles (8905 procedures) were retrieved. Female sex showed a positive moderate association with visual analogue scale at last follow-up (P = 0.02). Patient age had a negative association with the American Orthopaedic Foot and Ankle Score (P = 0.04) and Lysholm Knee Scoring Scale (P = 0.03). BMI was strongly associated with graft hypertrophy (P = 0.01). Greater values of VAS at baseline negatively correlate with lower values of Tegner Activity Scale at last follow-up (P < 0.0001).

Conclusion

The clinical outcomes were mostly related to the patients’ performance status prior surgery. A greater BMI was associated with greater rate of hypertrophy. Female sex and older age evidenced fair influence, while symptom duration prior to the surgical intervention and cartilage defect size evidenced no association with the surgical outcome. Lesion size and symptom duration did not evidence any association with the surgical outcome.

Is It Possible to Predict the Length of Stay of Patients Undergoing Hip-Replacement Surgery?

The proximal fracture of the femur and hip is the most common reason for hospitalization in orthopedic departments. In Italy, 115,989 hip-replacement surgeries were performed in 2019, showing the economic relevance of studying this type of procedure. This study analyzed the data relating to patients who underwent hip-replacement surgery in the years 2010-2020 at the "San Giovanni di Dio e Ruggi d'Aragona" University Hospital of Salerno. The multiple linear regression (MLR) model and regression and classification algorithms were implemented in order to predict the total length of stay (LOS). Lastly, using a statistical analysis, the impact of COVID-19 was evaluated. The results obtained from the regression analysis showed that the best model was MLR, with an R² value of 0.616, compared with XGBoost, Gradient-Boosted Tree, and Random Forest, with R² values of 0.552, 0.543, and 0.448, respectively. The t-test showed that the variables that most influenced the LOS, with the exception of pre-operative LOS, were gender, age, anemia, fracture/dislocation, and urinary disorders. Among the classification algorithms, the best result was obtained with Random Forest, with a sensitivity of the longest LOS of over 89%. In terms of the overall accuracy, Random Forest and Gradient-Boosted Tree achieved a value of 71.76% and an error of 28.24%, followed by Decision Tree, with an accuracy of 71.13% and an error of 28.87%, and, finally, Support Vector Machine, with an accuracy of 65.06% and an error of 34.94%. A significant difference in cardiovascular disease, fracture/dislocation, and post-operative LOS variables was shown by the chi-squared test and Mann-Whitney test in the comparison between 2019 (before COVID-19) and 2020 (in full pandemic emergency conditions).

Correlation of Postoperative Imaging With MRI and Clinical Outcome After Cartilage Repair of the Ankle: A Systematic Review and Meta-analysis

Background

Magnetic resonance imaging (MRI) is commonly used for evaluation of ankle cartilage repair, yet its association with clinical outcome is controversial. This study analyzes the correlation between MRI and clinical outcome after cartilage repair of the talus including bone marrow stimulation, cell-based techniques, as well as restoration with allo- or autografting.

Methods

A systematic search was performed in MEDLINE, Embase, and Cochrane Collaboration. Articles were screened for correlation of MRI and clinical outcome. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) were used. Chi-square test and regression analysis were performed to identify variables that determine correlation between clinical and radiologic outcome.

Results

Of 2687 articles, a total of 43 studies (total 1212 cases) were included with a mean Coleman score of 57 (range, 33-70). Overall, 93% were case series, and 5% were retrospective and 2% prospective cohort studies. Associations between clinical outcome and ≥1 imaging variable were found in 21 studies (49%). Of 24 studies (56%) using the composite magnetic resonance observation of cartilage repair tissue (MOCART) score, 7 (29%) reported a correlation of the composite score with clinical outcome. Defect fill was associated with clinical outcome in 5 studies (12%), and 5 studies (50%) reported a correlation of T2 mapping and clinical outcome. Advanced age, shorter follow-up, and larger study size were associated with established correlation between clinical and radiographic outcome (P = .021, P = .028, and P = .033).

Conclusion

Interpreting MRI in prediction of clinical outcome in ankle cartilage repair remains challenging; however, it seems to hold some value in reflecting clinical outcome in patients with advanced age and/or at a shorter follow-up. Yet, further research is warranted to optimize postoperative MRI protocols and assessments allowing for a more comprehensive repair tissue evaluation, which eventually reflect clinical outcome in patients after cartilage repair of the ankle.Level of Evidence: Level III, systematic review and meta-analysis.

Matrix-induced autologous chondrocyte implantation (mACI) versus autologous matrix-induced chondrogenesis (AMIC) for chondral defects of the knee: a systematic review

INTRODUCTION

Chondral defects of the knee are common and their treatment is challenging.

SOURCE OF DATA

PubMed, Google scholar, Embase and Scopus databases.

AREAS OF AGREEMENT

Both autologous matrix-induced chondrogenesis (AMIC) and membrane-induced autologous chondrocyte implantation (mACI) have been used to manage chondral defects of the knee.

AREAS OF CONTROVERSY

It is debated whether AMIC and mACI provide equivalent outcomes for the management of chondral defects in the knee at midterm follow-up. Despite the large number of clinical studies, the optimal treatment is still controversial.

GROWING POINTS

To investigate whether AMIC provide superior outcomes than mACI at midterm follow-up.

AREAS TIMELY FOR DEVELOPING RESEARCH

AMIC may provide better outcomes than mACI for chondral defects of the knee. Further studies are required to verify these results in a clinical setting.

The Role of Magnetic Resonance Imaging in Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: Analyzing MOCART 1 and 2.0

OBJECTIVE

To determine the role of magnetic resonance imaging (MRI) MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) 1 and 2.0 scores in the assessment of postoperative outcome after autologous matrix-induced chondrogenesis (AMIC) for the treatment of osteochondral lesions of the talus (OLTs). It was hypothesized that preoperative patient factors or OLT morphology are associated with postoperative MOCART scores; yet postoperative clinical outcome is not.

STUDY DESIGN

Cohort study; Level of evidence, 4. This study evaluated isolated AMIC that were implanted on the talus of 35 patients for the treatment of symptomatic OLT. Tegner and AOFAS (American Orthopaedic Foot and Ankle Society) scores were obtained at an average follow-up of 4.5 ± 1.8 years and postoperative MRI scored according to the MOCART 1 and 2.0.

RESULTS

OLT size showed significant correlation with postoperative MRI scores (MOCART 1: P = 0.006; MOCART 2.0: P = 0.004). Bone grafting was significantly associated with a MOCART 1 subscale (signal intensity of repair tissue; P = 0.038). Age and defect size showed significant correlations with MOCART 2.0 subscales (P < 0.05). Patients with shorter follow-up had a significantly higher MOCART 1 score and a trend toward better MOCART 2.0 scores than patients with longer follow-up (64.7 vs. 52.9 months, P = 0.02; 69.4 vs. 60.6 months, P = 0.058). No MOCART score was associated with postoperative patient-reported outcomes (n.s.).

CONCLUSION

Osteochondral lesion size is associated with postoperative MOCART scores in patients treated with AMIC for OLTs, with decreasing MOCART scores over time. Yet clinical outcome does not correlate with any MOCART score. Thus, MOCART assessment seems to have no significant role in the postoperative treatment of asymptomatic patients that underwent AMIC for OLTs.

Reliability of the MOCART score: a systematic review

BACKGROUND

The present systematic review analysed the available literature to assess reliability of the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score in the evaluation of knee and ankle osteochondral lesions.

METHODS

All the studies using the MOCART score for knee and/or talus chondral defects were accessed in March 2021. A multivariate analysis was performed to assess associations between the MOCART score at last follow-up and data of patients at baseline, clinical scores and complications. A multiple linear model regression analysis was used.

RESULTS

The MOCART score evidenced no association with patient age (P = 0.6), sex (P = 0.1), body mass index (P = 0.06), defect size (P = 0.9), prior length of symptoms (P = 0.9) or visual analogue scale (P = 0.07). For chondral defects of the knee, no statistically significant association was found between the MOCART score and the International Knee Documentation Committee (P = 0.9) and with the Lysholm Knee Scoring Scales (P = 0.2), Tegner Activity Scale (P = 0.2), visual analogue scale P = 0.07), rate of failure (P = 0.2) and revision (P = 0.9). For chondral defect of the talus, no statistically significant associations were found between the MOCART score and the American Orthopedic Foot and Ankle Score (P = 0.3), Tegner Activity Scale (P = 0.4), visual analogue scale (P = 0.1), rate of failure (P = 0.1) and revision (P = 0.7).

CONCLUSION

The MOCART score demonstrated no association with patient characteristics and with the surgical outcome in patients who underwent surgical management for knee and talus chondral defects.

LEVEL OF EVIDENCE

Level IV.

Autologous Chondrocyte Implantation and Mesenchymal Stem Cells for the Treatments of Chondral Defects of the Knee- A Systematic Review

BACKGROUND

There is still a lack of consensus about the best treatment of chondral defects of the knee. We conducted a systematic PRISMA review to evaluate clinical outcomes of Autologous Chondrocyte Implantation (ACI) and Mesenchymal Stem Cell (MSC) injections for the treatment of focal chondral defects of the knee.

METHODS

A systematic review of literature was performed according to the PRISMA guidelines. All the articles reporting data on ACI and MSC treatments for chondral defects of the knee were considered for inclusion. The main databases were accessed: PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar. The statistical analysis was performed using the Review Manager Software.

RESULTS

In the p-ACI group (987 knees), the Cincinnati Score improved by 18.94% (p=0.1), VAS by 38% (p=0.01), Tegner score by 19.11% (p=0.03), Lysholm score by 22.40% (p=0.01), IKCD by 27.36% (p=0.003). In the c-ACI group (444 knees), the Cincinnati Score improved by 23.80% (p=0.08), KOOS by 23.48% (p=0.03), VAS by 33.2% (p=0.005), IKDC by 33.30% (p=0.005). In the m-ACI group (599 knees), the Cincinnati Score improved by 26.80% (p=0.08), KOOS by 31.59% (p=0.1), VAS by 30.43% (p=0.4), Tegner score by 23.1% (p=0.002), Lysholm score by 31.14% (p=0.004), IKCD by 30.57% (p<0.001). In the MSCs group (291 knees), the KOOS improved by 29.7% (p=0.003), VAS by 41.89% (p<0.001), Tegner score by 25.81% (p=0.003), Lysholm score by 36.96% (p<0.001), IKCD by 30.57% (p=0.001).

CONCLUSION

Both ACI and MSC therapies can be considered as a concrete solution to treat focal chondral defects of the knee.

Matrix-assisted chondrocyte transplantation with bone grafting for knee osteochondritis dissecans: stable results at 12 years

PURPOSE

To document clinical and radiological results of arthroscopic matrix-assisted autologous chondrocyte transplantation (MACT) combined with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at long-term follow-up.

METHODS

Thirty-one knees in 29 patients (20.4 ± 5.7 years) were treated for symptomatic unfixable OCD lesions (2.6 ± 1.1 cm²) and prospectively evaluated at 2, 5, and 12 years (average, minimum 10 years). Patients were evaluated over time with IKDC subjective score, EQ-VAS, and Tegner scores. Failures were also documented. At the final follow-up, MRI evaluation was performed in 14 knees with the MOCART 2.0 score.

RESULTS

Beside 4 early failures, an overall clinical improvement was documented: the IKDC subjective score improved from 39.9 ± 16.8 to 82.1 ± 17.0 and 84.8 ± 17.2 at 2 and 5 years, respectively (p < 0.0005), and remained stable for up to 12 years (85.0 ± 20.2). EQ-VAS and Tegner scores presented similar trends, but patients did not reach their original activity level. Worse results were obtained for lesions bigger than 4 cm². At MRI evaluation, subchondral bone abnormalities were detected in over 85% of knees at long-term follow-up.

CONCLUSIONS

Arthroscopic bone grafting followed by MACT for unfixable knee OCD can offer a promising and stable clinical outcome over time in lesions smaller than 4 cm², with a low failure rate of 13%. Persistent subchondral alterations were documented at long-term MRI evaluation, suggesting the limits of this approach to regenerate the osteochondral unit in patients affected by knee OCD.

LEVEL OF EVIDENCE

IV.

Knee articular cartilage injury treatment with matrix-induced autologous chondrocyte implantation (MACI): correlation at 24 and 120 months between clinical and radiological findings using MR arthrography

OBJECTIVE

To evaluate the long-term evolution of matrix-induced autologous chondrocyte implantation (MACI) with magnetic resonance (MR) arthrography and verify the correlation between radiological and clinical findings.

MATERIALS AND METHODS

Twenty-six patients (20 m/6f) were diagnosed with knee chondral injuries and treated with MACI implantation. Each patient received MR arthrography and clinical examination at mid-term (range 22-36 months) and long term (range 96-194 months) after surgery. MR arthrography was performed with dedicated coil and a 1.5-Tesla MR unit. The modified MOCART scale was used to evaluate the status of chondral implants. Implant coating, integration to the border zone, and the surface and structure of the repaired tissue were evaluated. Presence of bone marrow oedema was evaluated. The Cincinnati Knee Rating System (CKRS) was used for clinical assessment.

RESULTS

At long term, 4/26 patients had complete alignment; 5/26 had a complete integration of the margins; in 4/26 cases, the implant surface was undamaged; in 14/26 cases, the reparative tissue was homogeneous. In 9/26 cases, the implant showed isointense signal compared to articular cartilage, while the presence of subchondral bone oedema was documented in 19/26 cases. The average radiological score decreased from 59.2 (mid-term) to 38.6 (long term). The average clinical score decreased from 8.9 to 8.3.

CONCLUSIONS

Decrease in clinical results was not significant (0.6 points p = .06), but mMOCART scores decreased significantly (p = .00003). Although imaging studies showed deterioration of the grafts, the patients did not have significant clinical deterioration (231/250).

Stable clinical long term results after AMIC in the aligned knee

INTRODUCTION

The aim of this study was to report a long-term follow-up of patients treated with autologous matrix-induced chondrogenesis (AMIC) for full-thickness chondral and osteochondral defects of the femoral condyle or patella combined with the correction of lower limb malalignment or patellar tracking if indicated.

METHODS

Thirty-three patients (thirty-four knees) were treated surgically for chondral and osteochondral cartilage defects of the knee joint. Regarding the origin of the lesion, patients were divided into three groups. Chondral lesions were observed in the patella (cP group) in fifteen patients, whereas eight patients demonstrated a femoral condylar location (cF group). Eleven patients presented with osteochondritis dissecans of the femur (ocF group). Associated procedures involving realignment of the patella, osteotomy around the knee, or cancellous bone grafting were performed when necessary. The mean size of the lesions was 2.8 ± 1.6 cm², and the mean patient age was 37.1 ± 11.9 years. To evaluate the clinical outcomes, the Lysholm score and the VAS pain score were imposed, as well as the reoperation rate.

RESULTS

After an average of 9.3 ± 1 years, follow-up was completed in 79% of the patients. Two patients from the cohort received a total knee prosthesis. The primary outcome measures (Lysolm and VAS pain) at 9-year follow-up were 85 ± 13 for the Lysholm score and 1.9 ± 1.6 for the VAS score in the entire analyzed population. Compared to the preoperative values (Lysholm 56 ± 19, VAS 5.8 ± 2.4) and the 2-year results (Lysholm 85 ± 16, VAS 2.0 ± 2.1), there was significant improvement in the first 2 years after intervention and a stable course in the long-term observation. The same was observed in the cP and ocF subgroups, whereas patients of the cF group showed even further improvement.

CONCLUSIONS

AMIC showed durable results in aligned knees. The favorable outcome was maintained after an average of 9 years when malalignment of the lower limb and patellar maltracking were corrected. Such data are particularly encouraging for young adult patients who may benefit from a procedure that circumvents early arthroplasty.

Increased Chondrocytic Gene Expression Is Associated With Improved Repair Tissue Quality and Graft Survival in Patients After Autologous Chondrocyte Implantation

BACKGROUND

Assays to quantitate the quality of autologous chondrocyte implants have recently become available. However, the correlation of the assay score with radiological and clinical outcomes has not been established.

PURPOSE/HYPOTHESIS

The purpose was to assess the influence of cell identity (chondrocyte/synoviocyte gene expression ratio) and viability on patient-reported outcome measures, graft survival, and repair tissue quality. It was hypothesized that greater cell product quality as assessed through an identity assay and cell viability is associated with superior outcomes after autologous chondrocyte implantation (ACI) for symptomatic cartilage defects.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Seventy-nine patients with a minimum follow-up of 2 years were included in this study. Of these, 67 patients were available for imaging assessment utilizing the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system. Patients were assigned to groups either below or above the cohort's mean based on their individual cell identity score and viability percentage.

RESULTS

Patients were predominantly female (57.7%) with a mean age of 30.0 ± 9.3 years. No differences were seen between Knee injury and Osteoarthritis Outcome Score, Lysholm, Tegner, or International Knee Documentation Committee Subjective Knee Evaluation Form within the viability and cell identity groups at a final follow-up of 3.8 ± 1.4 years after ACI (P > .05). In a subset of patients, the mean MOCART score was 68.3 ± 15.6 at an average magnetic resonance imaging follow-up of 17.7 ± 9.56 months. Low cell identity was significantly associated with the degree of defect filling (P = .025), integration of border zone (P = .01), effusion (P = .024), and ACI graft failure (P = .002). Patients with above-average cell identity scores had a significantly higher survival rate at 5-year follow-up compared with patients with below-average scores (95.8% vs 64.7%; P = .013). Cell viability did not influence MOCART subscales or graft failure (all P > .05). Cell viability and identity showed no significant correlation with each other (r = -0.045; P = .694).

CONCLUSION

Cell identity was significantly correlated with structural repair quality and graft survival after second-generation ACI for symptomatic chondral lesions in the knee. While improved imaging outcome and higher graft survivorship were associated with a higher individual cell identity score indicating a higher chondrocyte/synoviocyte gene expression ratio in the final cell product, clinical outcome did not correlate with the identity score.

Long-Term Clinical and MRI Results of Matrix-Assisted Autologous Chondrocyte Implantation for Articular Cartilage Defects of the Knee

OBJECTIVE

To evaluate the long-term clinical and radiological outcome of matrix-assisted autologous chondrocyte implantation (mACI) for articular cartilage defects in the knee joint.

DESIGN

Clinical evaluation was assessed in 21 patients with full-thickness cartilage defects, International Cartilage Repair Society (ICRS) grade IV. Clinical scoring was performed preoperatively and 12 years after transplantation using the International Knee Documentation Committee (IKDC) score, the Lysholm score, the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Noyes sports activity rating scale. Morphologic evaluation of the repair tissue was assessed by magnetic resonance imaging (MRI) in 14 patients using the Kreuz-Henderson score.

RESULTS

Clinical evaluation revealed significant improvement in the IKDC, the Lysholm, the KOOS, and the Noyes score. Morphological evaluation by MRI showed moderate to complete defect filling in 10 of 14 patients, demonstrating normal to nearly normal values in mean 74.29% of all assessed parameters. Significant correlation of the parameter cartilage signal and clinical outcome was found with the IKDC, Lysholm, and KOOS subscales ADL (activities of daily living) and QoL (quality of life).

CONCLUSIONS

The clinical and radiological outcomes 12 years after transplantation suggest the confirmation of the promising results of the mid-term follow-up. This study therefore provides first indications that the implantation of mACI might be a suitable option for long-term cartilage repair. Future controlled studies need to address the exact parameters influencing the long-term outcome of mACI.

Sustained Results in Long-Term Follow-Up of Autologous Chondrocyte Implantation (ACI) for Distal Femur Juvenile Osteochondritis Dissecans (JOCD)

INTRODUCTION

Concern regarding ability of autologous chondrocyte implantation (ACI) to correct for the bone and cartilage pathology of knee juvenile osteochondritis dissecans (JOCD) exists. The purpose of this study was to determine long-term, patient-based outcomes of ACI treatment of JOCD in young patients. Authors hypothesized long-term outcomes are comparable to reported mid-term outcomes.

METHODS

A single institution, longitudinal cohort study design combining medical record review and outcome surveys was used. Inclusion criteria included isolated JOCD diagnosis, failed primary healing of operatively treated JOCD, ACI surgery > 5 years ago, and ≤20 years of age at time of ACI.

RESULTS

10/26 eligible patients (38.5%) participated (M: F = 5:5, age at ACI: 18.3 ± 2.5 y, current age: 30.8 ± 5.1 y, and current BMI: 24.6 ± 2.1). Follow-up was 12.0 ± 4.5 y. Lesion size at ACI was 9.1 ± 1.9 cm². Femoral condyle location was medial = 6 and lateral = 4. All required treatment at some point for knee symptoms after ACI. During the past one year, four patients required treatment. Patient reported outcome scores at 12 years following ACI were IKDC score: 73.0 ± 3.6, KOOS scores including pain [88.7 ± 2.3], symptoms [78.2 ± 4.6], activity of daily living [94.7 ± 1.9], function, sports, and recreational activities [73.0 ± 5.3], and quality of life [57.5 ± 5.8], and Modified Cincinnati Knee Rating score was 77.9 ± 4.1. A moderate to good relationship was found between KOOS symptoms and BMI and lesion size. Function, sports, and recreational activities of the KOOS were greater in participants who had ≤1 lesion prior to ACI procedures (p = 0.044).

CONCLUSION

This study of ACI treatment of knee JOCD patients confirms sustained, long-term results. Number of lesions prior to ACI procedure influenced status of function, sports, and recreational activities.

Arthroscopic Treatment of Osteochondral Lesions of the Talus Using Juvenile Articular Cartilage Allograft and Autologous Bone Marrow Aspirate Concentration

Juvenile allogenic chondrocyte implantation (JACI; DeNovo NT Natural Tissue Graft^®; Zimmer, Warsaw, IN) with autologous bone marrow aspirate concentrate (BMAC) is a relatively new all-arthroscopic procedure for treating critical-size osteochondral lesions (OCLs) of the talus. Few studies have investigated the clinical and radiographic outcomes of this procedure. We collected the clinical and radiographic outcomes of patients who had undergone JACI-BMAC for talar OCLs to assess treatment efficacy and cartilage repair tissue quality using magnetic resonance imaging (MRI). Forty-six patients with critical-size OCLs (≥6 mm widest diameter) received JACI-BMAC from 2012 to 2014. We performed a retrospective medical record review and assessed the functional outcomes pre- and postoperatively using the Foot and Ankle Outcome Score (FAOS) and Short-Form 12-item general health questionnaire. MRI was performed preoperatively and at 12 and 24 months postoperatively. Cartilage morphology was evaluated on postoperative MRI scans using the magnetic resonance observation of cartilage tissue (MOCART) score. The pre- to postoperative changes and relationships between outcomes and lesion size, bone grafting, lesion location, instability, hypertrophy, and MOCART scores were analyzed. Overall, the mean questionnaire scores improved significantly, with almost every FAOS subscale showing significant improvement postoperatively. Concurrent instability resulted in more changes that were statistically significant. The use of bone grafting and the presence of hypertrophy did not result in statistically significant changes in the outcomes. Factors associated with outcomes were lesion size and hypertrophy. Increasing lesion size was associated with decreased FAOS quality of life subscale and hypertrophy correlating with changes in the pain subscale. Of the 46 patients, 22 had undergone postoperative MRI scans that were scored. The average MOCART score was 46.8. Most patients demonstrated a persistent bone marrow edema pattern and hypertrophy of the reparative cartilage. Juvenile articular cartilage implantation of the DeNovo NT allograft and BMAC resulted in improved functional outcome scores; however, the reparative tissue still exhibited fibrocartilage composition radiographically. Further studies are needed to investigate the long-term outcomes and determine the superiority of the arthroscopic DeNovo procedure compared with microfracture and other cartilage resurfacing procedures.

Comparison of Juvenile Allogenous Articular Cartilage and Bone Marrow Aspirate Concentrate Versus Microfracture With and Without Bone Marrow Aspirate Concentrate in Arthroscopic Treatment of Talar Osteochondral Lesions

BACKGROUND

The purpose of this study was to compare the functional and radiographic outcomes of patients who received juvenile allogenic chondrocyte implantation with autologous bone marrow aspirate (JACI-BMAC) for treatment of talar osteochondral lesions with those of patients who underwent microfracture (MF).

METHODS

A total of 30 patients who underwent MF and 20 who received DeNovo NT for JACI-BMAC treatment between 2006 and 2014 were included. Additionally, 17 MF patients received supplemental BMAC treatment. Retrospective chart review was performed and functional outcomes were assessed pre- and postoperatively using the Foot and Ankle Outcome Score and Visual Analog pain scale. Postoperative magnetic resonance images were reviewed and evaluated using a modified Magnetic Resonance Observation of Cartilage Tissue (MOCART) score. Average follow-up for functional outcomes was 30.9 months (range, 12-79 months). Radiographically, average follow-up was 28.1 months (range, 12-97 months).

RESULTS

Both the MF and JACI-BMAC showed significant pre- to postoperative improvements in all Foot and Ankle Outcome Score subscales. Visual Analog Scale scores also showed improvement in both groups, but only reached a level of statistical significance ( P < .05) in the MF group. There were no significant differences in patient reported outcomes between groups. Average osteochondral lesion diameter was significantly larger in JACI-BMAC patients compared to MF patients, but size difference had no significant impact on outcomes. Both groups produced reparative tissue that exhibited a fibrocartilage composition. The JACI-BMAC group had more patients with hypertrophy exhibited on magnetic resonance imaging (MRI) than the MF group ( P = .009).

CONCLUSION

JACI-BMAC and MF resulted in improved functional outcomes. However, while the majority of patients improved, functional outcomes and quality of repair tissue were still not normal. Based on our results, lesions repaired with DeNovo NT allograft still appeared fibrocartilaginous on MRI and did not result in significant functional gains as compared to MF.

LEVEL OF EVIDENCE

Level III, comparative series.

How to Manage a Failed Cartilage Repair: A Systematic Literature Review

Purpose  The aims of this paper are to report the rate and risk factors for the failure of the most common cartilage repair technique, and analyze the most important factors that could influence the choice of a specific surgical treatment to revise a failed cartilage repair.

Methods  A review of the literature was performed focusing on failed cartilage repair and related treatments. Two of the authors independently screened articles. Conflicts about the inclusion of a paper was resolved by further evaluation by the senior author. Review articles, articles written in languages different from/other than English, case reports, and papers that did not evaluate the outcomes of interest were excluded. Full-text version of each included paper was obtained and relevant data were extracted and collected in a database.

Results  At the end of the screening process, 31 articles were included. Microfractures and mosaicplasty showed a nonnegligible failure rate at short- and midterm. Better results, especially in terms of time to failure or revision, were reported with the use of autologous chondrocyte implantation (ACI) and osteochondral allograft (OCA) transplantation. Regarding the treatment of failed cartilage repair, the use of OCA transplantation in patients with previous failed cartilage repair may be a safe option. The revision of failed OCA transplantation with further OCA seems to have a greater failure rate. Patients with previous failed ACI or matrix-induced autologous chondrocyte implantation (MACI) who underwent further MACI or ACI reported acceptable results. Otherwise, ACI in patients with history of previous subchondral marrow stimulation (SMS) demonstrated a greater failure rate.

Conclusion  From the analysis of the literature, OCA transplantation seems to be the most reliable treatment of a failed SMS. ACI or MACI showed acceptable results in patients with previously failed MACI or ACI.

Level of Evidence  Level IV, systematic review of level I-IV studies.

Failure of Autologous Chondrocyte Implantation

Long-term results of autologous chondrocyte implantation and matrix-assisted autologous chondrocyte transplantation in the knee are satisfying, but not enough attention has been paid to the evaluation of failures. Thus, a systematic review of the literature was performed, underlining a failure rate in the 58 included articles of 14.9% among 4294 patients, most of them occurring in the first 5 years after surgery, and with no difference between autologous chondrocyte implantation and matrix-assisted autologous chondrocyte transplantation. Failures are very heterogenously defined in the current literature. A widely accepted definition is needed, and a comprehensive definition taking into consideration the patient's perception of the outcome, not just the surgeon's or researcher's point of view, would be advisable. Finally, there is no agreement on the most appropriate treatment of failures, and further studies are needed to give better indications to properly manage patients failed after cartilage procedures.

LEVEL OF EVIDENCE

Level IV.

Repair Potential of Matrix-Induced Bone Marrow Aspirate Concentrate and Matrix-Induced Autologous Chondrocyte Implantation for Talar Osteochondral Repair: Patterns of Some Catabolic, Inflammatory, and Pain Mediators

OBJECTIVE

The low regenerative potential of cartilage contributed to the development of different cell therapies aimed to improve the clinical outcome in young patients with Osteochondral Lesions of the Talus (OLT). This study is designed to assess the regenerative potential of autologous matrix-induced Bone Marrow Aspirate Concentrate (mBMAC) and matrix-induced Autologous Chondrocyte Implantation (mACI) evaluating, on a small number of osteochondral biopsies, the expression of some catabolic, inflammatory, and pain mediators.

DESIGN

Twenty-two patients with OLT were analyzed in this study; 7 were treated with mACI and 15 with mBMAC. Informed consent was obtained from all the patients. Clinical assessments were performed pre-operatively and at 12, 24, and 36 months after surgery using the American Orthopedic Foot and Ankle Society (AOFAS). Histology and immunohistochemistry were used to assess cartilage repair at 24 months. Data were analyzed using non-parametric Wilcoxon-Mann-Whitney and Spearman tests.

RESULTS

A remarkable improvement in AOFAS score was noticed for both treatments up to 36 months; however, patients treated with mACI reported the best AOFAS score. Various degrees of tissue remodeling were observed by histological analysis for both cell strategies. However, mBMAC treatment showed a higher expression of some fibrous and hypertrophic markers compared to mACI group. A mild positivity for nerve growth factor, as pain mediator, was noticed for both treatments.M.

CONCLUSIONS

Our findings demonstrated the best histological and clinical results following mACI treatment since different fibrotic and hypertrophic features were evident in the mBMAC group at 24-month follow-up.

Clinical Outcomes After Autologous Chondrocyte Implantation in Adolescents' Knees: A Systematic Review

PURPOSE

To perform a systematic review of the use of autologous chondrocyte implantation (ACI) in the adolescent knee.

SPECIFIC AIMS

(1) quantify clinical outcomes of ACI in adolescent knees, (2) identify lesion and patient factors that correlate with clinical outcome, and (3) determine the incidence of complications of ACI in adolescents.

METHODS

PubMed, MEDLINE, SCOPUS, CINAHL, and Cochrane Collaboration Library databases were searched systematically. Outcome scores recorded included the International Knee Documentation Committee score, the International Cartilage Repair Society score, the Knee Injury and Osteoarthritis Outcome Score, the visual analog scale, the Bentley Functional Rating Score, the Modified Cincinnati Rating System, Tegner activity Lysholm scores, and return athletics. Outcome scores were compared among studies based on proportion of adolescents achieving specific outcome quartiles at a minimum 1-year follow-up. Methodologic quality of studies was evaluated by Coleman Methodology Scores (CMSs).

RESULTS

Five studies reported on 115 subjects who underwent ACI with periosteal cover (ACI-P; 95, 83%), ACI with type I/type III collagen cover (ACI-C; 6, 5%), or matrix-induced ACI (MACI; 14, 12%). Mean patient age was 16.2 years (range, 11 to 21 years). All studies were case series. Follow-up ranged from 12 to 74 months (mean, 52.3 months). Mean defect size was 5.3 cm(2) (range, 0.96 to 14 cm(2)). All studies reported improvement in clinical outcomes scores. Graft hypertrophy was the most common complication (7.0%). The mean preoperative clinical outcome percentage (based on percentage of outcome scale used) was 37% (standard deviation [SD], 18.9%) and the mean postoperative clinical outcome percentage was 72.7% (SD, 16.9%). The overall percentage increase in clinical outcome scores was 35.7% (SD, 14.2%). Mean CMS was 47.8 (SD, 8.3).

CONCLUSIONS

Cartilage repair in adolescent knees using ACI provides success across different clinical outcomes measures. The only patient- or lesion-specific factor that influenced clinical outcome was the shorter duration of preoperative symptoms.

LEVEL OF EVIDENCE

Level IV, systemic review of Level I-IV studies.

Dry Arthroscopic Single-Stage Cartilage Repair of the Knee Using a Hyaluronic Acid-Based Scaffold With Activated Bone Marrow-Derived Mesenchymal Stem Cells

Cartilage lesions of the knee are a frequent finding; however, treatment options that are capable of restoring hyaline-like tissue are not routinely used. Cell-based technology such as autologous chondrocyte implantation may in some cases provide durable cartilage repair, but availability of this procedure is often restricted due to cost constraints. There have been promising outcomes reported with the use of scaffolds seeded with activated bone marrow aspirate concentrate in cases of chondral injury. There are clear advantages to cell-based cartilage repair techniques that are performed as a single-stage procedure, particularly when the repair technology can be used in a minimally invasive manner. We present an arthroscopic technique of cartilage repair using a hyaluronic acid-based scaffold associated with activated bone marrow aspirate concentrate. This technique is a cost-effective, minimally invasive, single-stage procedure that has the potential for routine use in a wide range of cartilage lesion types and locations.