Matrix-Associated Autologous Chondrocyte Implantation Is an Effective Treatment at Midterm Follow-up in Adolescents and Young Adults.

BACKGROUND: Autologous chondrocyte implantation (ACI) is an established method for treating cartilage defects in the knee of adult patients. However, less is known about its effectiveness in adolescents. HYPOTHESIS: Third-generation matrix-associated ACI (MACI) using spheroids (co.don chondrosphere/Spherox) is an effective and safe treatment for articular cartilage defects in adolescents aged 15 to 17 years, with outcomes comparable with those for young adults aged 18 to 34 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 71 patients (29 adolescents, 42 young adults) who had undergone ACI using spheroids were evaluated retrospectively in this multicenter study. For adolescents, the mean defect size was 4.6 ± 2.4 cm2, and the follow-up range was 3.5 to 8.0 years (mean, 63.3 months). For young adults, the mean defect size was 4.7 ± 1.2 cm2, and the follow-up range was 3.8 to 4.3 years (mean, 48.4 months). At the follow-up assessment, outcomes were assessed by using validated questionnaires (Knee injury and Osteoarthritis Outcome Score [KOOS], International Knee Documentation Committee [IKDC] subjective knee evaluation form and current health assessment form, and modified Lysholm score), the magnetic resonance observation of cartilage repair tissue (MOCART) score, and if relevant, time to treatment failure. Safety was assessed by the treatment failure rate. RESULTS: No significant difference between the 2 study groups was found for KOOS, IKDC, or MOCART scores, with all patients achieving high functional values. A significant difference was found in the modified Lysholm score, favoring the young adult group over the adolescent group (22.3 ± 1.9 vs 21.0 ± 2.4, respectively; P = .0123). There were no differences between the rates of treatment failure, with 3% in the adolescent group and 5% in the young adult group. CONCLUSION: Third-generation MACI using spheroids is a safe and effective treatment for large cartilage defects of the knee in adolescents at midterm follow-up. Outcomes are comparable with those for young adults after ACI.

Morphological and Quantitative 7 T MRI of Hip Cartilage Transplants in Comparison to 3 T-Initial Experiences.

OBJECTIVES: The aims of this study were to evaluate morphological and quantitative 7 T magnetic resonance imaging (MRI) hip sequences in patients after acetabular cartilage transplantation and to compare image quality with 3 T MRI. MATERIALS AND METHODS: Following approval from the local institutional ethics committee and signing informed consent, 9 patients with history of autologous acetabular cartilage transplantation were imaged at 7 T and 3 T MRI. Sequences (3-dimensional dual echo steady state, 3-dimensional T1 volume interpolated breath-hold examination, sagittal proton density [PD] turbo spin echo and coronal fat-saturated PD turbo spin echo, sagittal T1 mapping in dual flip angle technique, and multiecho spin echo/gradient echo sequences for T2 and T2* mapping) were applied after the intravenous application of Gd-DTPA according to a protocol for delayed gadolinium-enhanced MRI of cartilage and manual B1 shimming at 7 T. Images were compared intraindividually regarding image quality and assessability of cartilage structures using 5-point scales (1 = 3 T clearly superior, 5 = 7 T clearly superior) in consensus with 2 radiologists. Contrast ratios were calculated between articular cartilage, joint fluid, and subchondral bone. An adapted MOCART (MR observation of cartilage repair tissue) score was assessed independently at 3 T and 7 T. Relaxation times were measured in the transplanted acetabular region and in 2 reference regions by 2 readers independently to calculate interreader reliability. Statistical significances of field strength comparisons were calculated using Student t test and t test for dependent measurements. RESULTS: A 7 T MRI was superior to 3 T MRI in the majority of the sequences regarding subjective ratings. Furthermore, 7 T yielded comparable or better contrast ratios compared with 3 T. The criteria of the MOCART score matched totally at 3 T and 7 T, apart from the signal intensity of the repair tissue in PDw, which was rated higher at 7 T in 5 patients. Interreader reliability of all relaxation times was excellent. T1 and T2* relaxation times were significantly shorter at 7 T compared with 3 T. T2 relaxation times were longer at 7 T compared with 3 T without statistical significance. No significant difference could be seen when comparing the relaxation ratios (relaxation times after standardization to reference regions) of the cartilage transplant between the 2 field strengths. CONCLUSIONS: This study shows the feasibility of morphological and quantitative 7 T hip MRI in patients after acetabular cartilage transplantation and its predominant superiority regarding image quality, assessment of cartilage transplants, and contrast over 3 T MRI. To compare relaxation times between the field strengths, the calculation of intraindividual ratios is recommended.

Is early treatment of cam-type femoroacetabular impingement the key to avoiding associated full thickness isolated chondral defects?

PURPOSE: Hip arthroscopy is a safe and reproducible method for treating femoroacetabular impingement (FAI) and has evolved greatly in recent years. But little is known about the influences on the outcome after surgery. The aims of the current study were to elucidate (1) which parameters can be used as a marker for the presence of chondral and labral lesions, (2) the postoperative clinical outcome, and (3) at which time after surgery recovery occurs. METHODS: A prospective study was performed with 177 patients who underwent hip arthroscopy because of cam-type FAI. The patients were examined preoperatively as well as 6 weeks and 6 months postoperatively, and their condition was rated according to the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Non-Arthritic Hip Score (NAHS). Statistical analyses were performed to evaluate the influence of independent factors such as "patient age," "pain duration before surgery" on the clinical outcome, and the appearance of chondral or labral defects. RESULTS: The NAHS and WOMAC scores showed a significant enhancement 6 weeks after surgery. Only the NAHS showed a further improvement after 6 months. A positive correlation with the dependent variable "chondral lesion" was evaluated for the independent variables "pain duration before surgery," "preoperative NAHS," and "labrum lesion". Using ROC analysis, the optimal cutoff value of "pain duration before surgery" as a predictor was 9.5 months, for the NAHS 42.5 points. For the dependent variable, "6-month postoperative NAHS" significant correlations for the independent variables "age" and "pain duration before surgery" were revealed with a cutoff value of 55.5 years, respectively, 23.5 months. CONCLUSIONS: It was concluded from the results that the date of surgery is relevant for the appearance of chondral defects. Patient age is a further relevant factor for clinical outcome. Recovery after hip arthroscopy takes place mainly in the first 6 weeks after surgery. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Arthroscopic three-dimensional autologous chondrocyte transplantation using spheroids for the treatment of full-thickness cartilage defects of the hip joint.

PURPOSE: Treatment of full-thickness cartilage defects in the hip is a major issue for orthopaedic surgeons. Autologous matrix-induced three-dimensional chondrocyte transplantation using three-dimensional spheroids (ACT 3D) may be an option for treatment. The aim of the study is to describe the feasibility and first clinical results of ACT 3D with spheroids at the hip. METHODS: In this report, the surgical technique was described for the first time, and the outcome of sixteen patients with chondral defects induced by cam-type femoroacetabular impingement (FAI) who were followed up in a prospective study was evaluated. All patients underwent physical examination before the first surgery and again before the second (about 6 weeks later). Further examinations were performed 6 weeks after the second surgery and at an average follow-up period of 16.09 months. At every visit, the non-arthritic hip score (NAHS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were obtained. In addition, patient satisfaction was evaluated during the last follow-up examination by means of a questionnaire. RESULTS: The NAHS and WOMAC scores had significantly improved 6 weeks after arthroscopic treatment of the cam-type FAI, and a further significant enhancement was seen 6 weeks after the second surgery with application of the chondrocyte spheroids. In the last follow-up, the mean results were equally as good as the second follow-up examination 12 weeks after surgery. CONCLUSIONS: The present study shows that ACT 3D using spheroids is a feasible method that can be easily performed during arthroscopy. As the first results have been encouraging, the ACT 3D with spheroids at the hip should be continued. More studies should be initiated to get an impression of the quality grade of this method in comparison with other treatment options in case of chondral defects at the hip. LEVEL OF EVIDENCE: III.

3 Tesla high-resolution and delayed gadolinium enhanced MR imaging of cartilage (dGEMRIC) after autologous chondrocyte transplantation in the hip.

BACKGROUND: To evaluate the feasibility of 3 Tesla (T) high-resolution and gadolinium enhanced MRI of cartilage (dGEMRIC) in the thin and rounded hip cartilage of patients after acetabular matrix-based autologous chondrocyte transplantation (MACT). METHODS: Under general ethics approval, 24 patients were prospectively examined 6-31 months after acetabular MACT at 3T using high-resolution proton-density weighted (PDw) images (bilateral PD SPACE, 0.8 mm isotropic; unilateral PD-TSE coronal/sagittal, 0.8 × 0.8 resp. 0.5 × 0.5 × 2.5 mm) as well as T1 mapping (3D-FLASH, 0.78 mm isotropic) in dGEMRIC technique, and clinically scored. The cartilage transplant was evaluated using an adapted MOCART score (maximum 85 points). T1 relaxation times were measured independently by two radiologists. Here, regions of interest were placed manually in automatically calculated relaxation-maps, both in the transplant and adjacent healthy cartilage regions. Interobserver reliability was estimated by means of intraclass-correlation (ICC). RESULTS: The transplant was morphologically definable in the PDw images of 23 patients with a mean MOCART score of 69 points (60-80 points, SD 6.5). T1 maps showed a clear differentiation between acetabular and femoral cartilage, but correlation with PDw images was necessary to identify the transplant. Mean T1 relaxation times of the transplant were 616.3 ms (observer 1) resp. 610.1 ms (observer 2), and of adjacent healthy acetabular cartilage 574.5 ms (observer 1) resp. 604.9 ms (observer 2). Interobserver reliability of the relaxation times in the transplant was excellent (ICC-coefficient 0.88) and in adjacent healthy regions good (0.77). CONCLUSION: High-resolution PDw imaging with adapted MOCART scoring and dGEMRIC is feasible after MACT in the thin and rounded hip cartilage.