Injectable cultured bone marrow derived mesenchymal cells vs chondrocytes in the treatment of chondral defects of the knee - RCT with 6 years follow-up.

Articular cartilage has unique biological and biomechanical characteristics. Damage to this tissue fails to heal spontaneously, leading to progressive arthritis. Cartilage repair techniques have been looked forward to in the treatment of significant cartilage injuries. Cell-based regenerative techniques like the two-staged cultured chondrocytes and single-stage mesenchymal cell transplantation have been tried with varying results and limitations. We study the outcomes of cultured bone marrow derived MSCs in the treatment of articular cartilage defects of the knee in comparison to autologous cultured chondrocyte implantation (ACI). Both cultured MSC and ACI treatment methods resulted in significant improvements in patient reported outcome measures (PROMs). There was no difference in the PROMs, MOCART scores, T2∗ mapping and dGEMRIC values between the groups. Use of cultured MSCs leads to good clinical outcomes similar to ACI and represents a promising treatment to restore the articular cartilage in the knee.

Higher patient knowledge and resilience improve the functional outcome of primary total knee arthroplasty.

BACKGROUND: A significant percentage of patients have an unfavorable outcome following primary total knee arthroplasty (TKA). This study aimed to evaluate whether specific knowledge about the implant and resilience can influence the functional outcome following TKA. METHODS: A consecutive series of 163 patients following primary TKA at a mean age of 70 years (SD 9.1 years) were included at a regional rehabilitation center between December 2015 and December 2016. Specific patient knowledge (scale 0-7), Connor Davidson Resilience Scale (CD-RISC), Western Ontario and McMaster Universities (WOMAC) score, University of California and Los Angeles (UCLA) score and constitutional parameters were assessed on admission. Pearson's correlation analysis and stepwise linear regression analysis were performed to investigate associations between knowledge, resilience and functional scores. RESULTS: The mean overall knowledge score was 3.5 out of 7 and the mean resilience score was 72.9 out of 100. Mean WOMAC and UCLA scores on admission were 23.8 and 5.5, respectively. Stepwise linear regression analysis identified knowledge and age as significant predictors of WOMAC scores (R2 = 14.3%, p = 0.003). Knowledge and resilience were identified as significant predictors of UCLA scores (R2 = 13.8%, p = 0.013). CONCLUSION: This study highlights the importance of patient-related factors as part of an integral patient care concept in TKA. Although the identified predictors still need to be refined, it could be demonstrated how better patient knowledge might ultimately lead to better functional outcome following TKA. Routinely assessing patients' resilience might be a useful tool to identify patients at risk for low activity levels. LEVEL OF EVIDENCE: III. Patient-reported outcome study.

Evaluation of Meniscal Tissue after Meniscal Repair Using Ultrahigh Field MRI.

The study evaluates the meniscal tissue after primary meniscal suturing using 7-Tesla (T) magnetic resonance imaging with T2* mapping at 6 and 12 months after surgery to investigate the differences between repaired meniscal tissue and healthy meniscal tissue in the medial and lateral compartment. This prospective study included 11 patients (9m/2f) with a mean age of 30.6 years (standard deviation 9.0). Patients with a meniscal tear that was treated arthroscopically with meniscus suturing, using an all-inside technique, were included. All patients and seven healthy volunteers were imaged on a 7-T whole-body system. T2* mapping of the meniscus was applied on sagittal slices. Regions-of-interest were defined manually in the red and white zone of each medial and lateral meniscus to measure T2*-values. In the medial posterior and medial anterior horn similar T2*-values were measured in the red and white zone at 6- and 12-month follow-up. Compared with the control group higher T2*-values were found in the repaired medial meniscus. After 12-months T2*-values decreased to normal values in the anterior horn and remained elevated in the posterior horn. In the red zone of the lateral posterior horn a significant decrease in the T2*-values (from 8.2 milliseconds to 5.9 milliseconds) (p = 0.04), indicates successful repair; a tendency toward a decrease in the white zone between the 6 and 12 months follow-up was observed. In the red zone of the lateral anterior horn the T2*-values decreased significantly during follow-up and in the white zone of the lateral anterior horn T2*-values were comparable. In comparison to the control group higher T2*-values were measured at 6-months; however, the T2*-values showed comparable values in the repaired lateral meniscus after 12 months. The T2* mapping results of the current study indicated a better healing response of the red zone of the lateral posterior horn compared with the medial posterior horn.

Compositional magnetic resonance imaging in the evaluation of the intervertebral disc: Axial vs sagittal T2 mapping.

The aim of this study was to assess T2 values of the lumbar intervertebral discs in the axial and sagittal plane views and assess their respective interobserver reliability. The lumbar intervertebral discs of 23 symptomatic patients (11 female; 12 male; mean age, 44.1 ± 10.6; range, 24-64 years) were examined at 3T. Region-of-interest (ROI) analysis was performed on axial and sagittal T2 maps by two independent observers. Intraclass correlation coefficient (ICC) was assessed for every ROI. The interobserver agreement was excellent for the nucleus pulposus (NP) in the sagittal (0.951; 95% confidence interval [CI], 0.926-0.968) and axial (0.921; 95% CI, 0.845-0.955) planes. The posterior 20% region showed a higher ICC in the axial vs the sagittal assessment (0.845; 95% CI, 0.704-0.911 vs 0.819; 95% CI, 0.744-0.873). The same was true for the posterior 10%, with the axial ROI showing a higher ICC (0.923; 95% CI, 0.865-0.953 vs 0.628; 95% CI, 0.495-0.732). The intraobserver agreement was excellent for every ROI except the sagittal 10% region, which showed good performance (0.869; 95% CI, 0.813-0.909). The sagittal nucleus pulposus was the best-performing ROI with regard to intra- and interobserver agreement in the T2 assessment of the lumbar intervertebral disc. However, the axial NP showed more stable agreements overall and across the value range. In addition, the annular analysis showed better inter- and intraobserver agreement in the axial plane view. Clinical significance: Based on the presented analysis, we highly recommend that further studies use axial T2 mapping due to the higher intra- and interreader agreement.

Articular cartilage repair using autologous collagen-induced chondrogenesis (ACIC): a pragmatic and cost-effective enhancement of a traditional technique.

PURPOSE: The autologous collagen-induced chondrogenesis technique is described, and the results of a 6-year follow-up clinical study using this technique are presented. METHODS: 30 patients with International Cartilage Repair Society (ICRS) Grade III/IVa symptomatic chondral defects of the knee treated with enhanced microdrilling using atelocollagen were prospectively examined in this clinical series. The median age of the patients was 39.0 years (range 19-61 years). Patients were followed up to 72 months. Clinical evaluation was performed using functional knee scores and radiologically. Both quantitative and qualitative assessments were performed. RESULTS: Statistically significant and clinically relevant improvement was observed in 2 years and was sustained for the 6 years of the study observation. At 6 years, the mean Lysholm score was 79.7 (SD 6.8) compared to 52.6 (SD 10.7) pre-operatively (p < 0.05). The symptomatic Knee Injury and Osteoarthritis Outcome Score (KOOS) improved from 68.3 (SD 11.4) to 90.2 (SD 4.3) (p < 0.05). The subjective International Knee Documentation Committee (IKDC) also showed improvement from 39.1 (SD 4.1) to 81.6 (SD 7.8) (p < 0.05). The calculated T2* relaxation times were 26.0 (SD 4.2) seconds and 30.3 (SD 6.2) seconds for the repair tissue and native cartilage, respectively. The average magnetic resonance observation of cartilage repair tissue (MOCART) score was 78.5 (SD 9.6) for all lesions. CONCLUSION: The enhanced microdrilling using atelocollagen is an enhancement of the traditional microfracture method using an off-the-shelf product. When used to treat moderate to severe chondral lesions, this enhancement produces hyaline-like cartilage with a corresponding improvement in symptoms. LEVEL OF EVIDENCE: IV.

The role of the subchondral layer in osteonecrosis of the femoral head: analysis based on HR-QCT in comparison to MRI findings.

BACKGROUND: Non-traumatic avascular osteonecrosis of the femoral head (ONFH) is a severe disease causing destruction of the hip joint, often necessitating total hip arthroplasty (THA) even in young patients. Magnetic resonance imaging (MRI) is commonly used for diagnosis of ONFH, but provides limited insight into the subchondral bone microstructure. PURPOSE: To analyze routine MRI findings in comparison to high-resolution quantitative computed tomography (HR-QCT) with a special focus on the subchondral layer and to estimate the importance of differences determining the indication for THA. MATERIAL AND METHODS: Twelve patients with ONFH were included before THA. Preoperative MRI and HR-QCT of the retrieved femoral heads were aligned using a registration algorithm. Pathological findings and trabecular bone parameters in matched areas were analyzed by two readers. McNemar, marginal homogeneity test, and Pearson's correlation coefficient were used for comparison. RESULTS: Subchondral delamination was found in nine cases on HR-QCT, but missed or underestimated in all but one case on MRI ( P = 0.016). Chondral discontinuity was found in all cases on HR-QCT and in two cases on MRI ( P = 0.016). Areas of complete bone resorption on HR-QCT were linked to high signal intensity on 3D gradient-echo MRI sequences with water-selective excitation, while there was no correlation between trabecular bone parameters and MRI signal intensities in other areas ( P = 0.304). CONCLUSION: Subchondral delamination, subchondral resorption, and chondral discontinuity are found frequently in advanced stages of ONFH. These lesions tend to be underestimated on conventional MRI. Our results support the importance of CT imaging in the evaluation of ONFH.

Prediction of Lumbar Disk Herniation and Clinical Outcome Using Quantitative Magnetic Resonance Imaging: A 5-Year Follow-Up Study.

OBJECTIVES: The aim of this study was to assess the predictive value of T2 mapping at baseline with regard to the development of disk herniation and clinical outcome at a 5-year follow-up in patients with low back pain. MATERIALS AND METHODS: Twenty-five symptomatic patients (13 male; mean age, 44.0 years; range, 24-64 years at baseline) were examined at 3 T magnetic resonance imaging, with a 5-year follow-up. Region of interest analysis was performed on 125 lumbar intervertebral disks on 2 central sagittal T2 maps. Absolute T2 relaxation times and a T2 value ratio of the posterior annulus fibrosus as a percentage of the nucleus pulposus (NPAF) were evaluated for each disk. All disks were graded morphologically using the Pfirrmann score. Roland-Morris Disability Questionnaires (RMDQ) and a visual analogue scale (VAS) were assessed for each patient at follow-up as a clinical end point and compared with diagnosed lumbar disk herniation. Statistical analysis was conducted by a biomedical statistician. RESULTS: Using the baseline NPAF ratio, follow-up development of herniation was predicted with an area under the curve (AUC) of 0.893 in a receiver operating characteristic curve. The same was done using the baseline nucleus pulposus T2, resulting in an AUC of 0.901. Baseline and follow-up NPAF, as well as baseline and follow-up nucleus pulposus T2, differed significantly (P < 0.001) between disks with no herniation, disks with herniation at baseline, and disks with new herniation at follow-up. Difference was still significant (all P < 0.001), when only testing for difference in degenerated discs with Pfirrmann score III to V. Calculating sensitivity and specificity for herniation prediction only in discs with Pfirmann III to V using a receiver operating characteristic, AUC was 0.844 with baseline herniations excluded.The lowest baseline nucleus pulposus T2 per patient correlated significantly with follow-up RMDQ (r = -0.517; P = 0.008) and VAS (r = -0.494; P = 0.012). The highest baseline NPAF correlated significantly with RMDQ (r = 0.462; P = 0.020), but not VAS (r = 0.279; P = 0.177). CONCLUSIONS: Quantitative T2 mapping may serve as a clinically feasible, noninvasive imaging biomarker that can indicate disks at risk for herniation and correlates with clinical outcome and subjective patient burden in a representative cohort of patients with low back pain.

Vessel architecture in human knee cartilage in children: an in vivo susceptibility-weighted imaging study at 7 T.

OBJECTIVES: To evaluate the clinical feasibility of ultrahigh field 7-T SWI to visualize vessels and assess their density in the immature epiphyseal cartilage of human knee joints. METHODS: 7-T SWI of 12 knees (six healthy volunteers, six patients with osteochondral abnormalities; mean age 10.7 years; 3 female, 9 male) were analysed by two readers, classifying intracartilaginous vessel densities (IVD) in three grades (no vessels, low IVD and high IVD) in defined femoral, tibial and patellar zones. Differences between patients and volunteers, IVDs in different anatomic locations, differences between cartilage overlying osteochondral abnormalities and corresponding normal zones, and differences in age groups were analysed. RESULTS: Interrater reliability showed moderate agreement between the two readers (κ = 0.58, p < 0.001). The comparison of IVDs between patients and volunteers revealed no significant difference (p = 0.706). The difference between zones in the cartilage overlying osteochondral abnormalities to corresponding normal zones showed no significant difference (p = 0.564). IVDs were related to anatomic location, with decreased IVDs in loading areas (p = 0.003). IVD was age dependent, with more vessels present in the younger participants (p = 0.001). CONCLUSIONS: The use of SWI in conjunction with ultrahigh field MRI makes the in vivo visualization of vessels in the growing cartilage of humans feasible, providing insights into the role of the vessel network in acquired disturbances. KEY POINTS: • SWI facilitates in vivo visualization of vessels in the growing human cartilage. • Interrater reliability of the intracartilaginous vessel grading was moderate. • Intracartilaginous vessel densities are dependent on anatomical location and age.

Matrix Production Affects MRI Outcomes After Matrix-Associated Autologous Chondrocyte Transplantation in the Knee.

BACKGROUND: Matrix-associated autologous chondrocyte transplantation (MACT) has been an effective therapy for large, full-thickness cartilage lesions for years. However, little is known about how graft maturation is affected by characteristics of transplanted chondrocytes. PURPOSE: To investigate the influence of gene expression of chondrocytes at the time of transplantation on MRI outcomes up to 2 years after MACT. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study included 25 patients with 27 symptomatic traumatic defects of articular cartilage, who had undergone MACT in the knee. Postoperative MRI examinations were conducted at 3, 6, 12, and 24 months after surgery. Biochemical graft maturation was assessed by measuring T2 relaxation time values of the transplant and healthy native cartilage areas. The MOCART (magnetic resonance observation of cartilage repair tissue) score was used to evaluate the morphological quality of regeneration tissue. Gene expression (collagen type I, collagen type II, aggrecan, versican, and interleukin-1ß) was determined by real-time polymerase chain reaction (PCR) in transplant residuals at the time point of transplantation and was correlated with MRI outcomes using Spearman's rank correlation coefficient. A Friedman test with post hoc analysis (Wilcoxon signed rank test) conducted with a Bonferroni correction was applied to compare scores at different time points. RESULTS: T2 relaxation time of regeneration tissue improved from a mean ± SD of 74.6 ± 20.1 milliseconds at 3 months to 47.9 ±13.3 milliseconds at 24 months ( P < .003). These values were similar to the T2 relaxation times of the native surrounding cartilage (50.9 ± 15 ms). The calculated T2 index (ratio of regeneration tissue to native cartilage) improved from 1.63 ± 0.76 at 3 months to 1.0 ± 0.4 at 24 months ( P < .011). The MOCART score increased from 51.6 ± 15 points to 72.4 ± 12.2 points ( P < .001). Improvement of the T2 index over time significantly correlated with aggrecan, COL1A1, COL2A1, and versican expression ( rs = 0.9, P < .001; rs = 0.674, P < .012; rs = 0.553, P < .05; and rs = 0.575, P < .04, respectively). No correlation was found for IL-1ß. CONCLUSION: These data demonstrate that matrix production in transplanted chondrocytes affects maturation of MACT grafts in MRI 2 years after surgery.

Erratum to: Autologous Bone-marrow Mesenchymal Cell induced Chondrogenesis: Single-stage Arthroscopic Cartilage Repair.

[This corrects the article DOI: 10.1007/s13770-014-0061-4.].

Does T2 mapping of the posterior annulus fibrosus indicate the presence of lumbar intervertebral disc herniation? A 3.0 Tesla magnetic resonance study.

PURPOSE: Indicating lumbar disc herniation via magnetic resonance imaging (MRI) T2 mapping in the posterior annulus fibrosus (AF). METHODS: Sagittal T2 maps of 313 lumbar discs of 64 patients with low back pain were acquired at 3.0 Tesla (3T). The discs were rated according to disc herniation and bulging. Region of interest (ROI) analysis was performed on median, sagittal T2 maps. T2 values of the AF, in the most posterior 10% (PAF-10) and 20% of the disc (PAF-20), were compared. RESULTS: A significant increase in the T2 values of discs with herniations affecting the imaged area, compared to bulging discs and discs with lateral herniation, was shown in the PAF-10, where no association to the NP was apparent. The PAF-20 exhibited a moderate correlation to the nucleus pulposus (NP). CONCLUSIONS: High T2 values in the PAF-10 suggest the presence of disc herniation (DH). The results indicate that T2 values in the PAF-20 correspond more to changes in the NP.

Prognostic factors for mid-term symptom relief after open surgical correction for femoroacetabular impingement.

BACKGROUND: We sought to identify, which patient and radiographic factors at preoperative and 1-year follow up will predict patient symptom relief at mid-term. MATERIALS AND METHODS: A total of 50 hips in 47 patients with symptomatic FAI were included in this retrospective study. We stratified the hips into "success" and "failure" groups based on the change from baseline to mid-term follow up WOMAC pain score (mean follow up of 5.8 years). An attempt was made to identify factors that are predictive of mid-term outcome among preoperative radiographic measures, dGEMRIC index, range of motion and WOMAC score as well as 1-year follow-up range of motion, radiographic measures, and WOMAC pain scores. RESULTS: At 1-year follow up, the success rate was 72% (36/50) and at mid-term follow the success rate increased to 82% (41/50). There were no significant associations between mid-term pain scores and baseline factors (all p-values ≥0.10). One-year pain score and hip internal rotation was associated with poor mid-term pain scores but only the 1-year pain score was associated with the mid-term success/failure outcome. CONCLUSIONS: We did not identify clear preoperative predictors of mid-term results but patients with poor pain scores and limited hip internal rotation at 1-year follow-up are less likely to do well at mid-term.

Does periacetabular osteotomy for hip dysplasia modulate cartilage biochemistry?

BACKGROUND: The aim of periacetabular osteotomy is to improve joint mechanics in patients with developmental dysplasia of the hip. In our study, we tried to determine whether the proteoglycan content, as measured with delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), can be modulated with the alteration of the hip joint biomechanics. METHODS: In this prospective cohort study, thirty-seven patients (thirty-seven hips) with no or minimal osteoarthritis were treated with periacetabular osteotomy for symptomatic acetabular dysplasia. All patients had preoperative and one-year follow-up dGEMRIC scans. Twenty-eight of the thirty-seven also had two-year scans. The changes in dGEMRIC findings and hip morphology between the preoperative visit and the examinations at one and two years following the periacetabular osteotomy were assessed. RESULTS: The mean preoperative dGEMRIC index (and standard deviation) was 561.6 ± 117.6 ms; this decreased to 515.2 ± 118.4 ms at one year after periacetabular osteotomy but subsequently recovered to 529.2 ± 99.1 ms at two years postoperatively. The decrease in the dGEMRIC index of the acetabular cartilage after surgery appears to be most pronounced at the superior aspect of the acetabulum, where the decrease in mechanical loading after periacetabular osteotomy would be most pronounced. All domains of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) demonstrated significant improvement from the preoperative to the postoperative visits (all p < 0.001). CONCLUSIONS: Periacetabular osteotomy for developmental dysplasia of the hip appears to alter the mechanical loading of articular cartilage in the hip, which in turn alters the cartilage matrix composition, as demonstrated by dGEMRIC.

3D-isotropic high-resolution morphological imaging and quantitative T2 mapping as biomarkers for gender related differences after matrix-associated autologous chondrocyte transplantation (MACT).

The aim of this study was to determine in vivo high-resolution morphological and biochemical gender related differences in cartilage repair tissue (MACT). Forty patients were examined clinically and by MR scans at 3T-MRI (coronal 3D True-FISP sequence for morphologic assessment and multi-echo spin-echo T2-mapping for biochemical assessment of healthy cartilage and MACT cartilage). Mean T2 values in repair tissue in the deep zone showed significantly shorter T2 times in females (p = 0.009, female 43.5 ± 9.8 vs. male 48.2 ± 7.7 ms). The superficial zone showed higher T2 values than the deep zone in both the groups (female 48.5 ± 9.8, males 52.6 ± 11.0 ms) without significant difference between female and male patients. Native control cartilage showed no statistically significant differences for T2 between females and males. The subdivisions "structure of the repair tissue" and "subchondral bone" of the MOCART score showed statistically significant differences between females and males (p = 0.026 and p = 0.007) as well as the Lysholm score (p = 0.03). Our investigations revealed differences between female and male patients after MACT of the knee in clinical outcome and advanced morphological and biochemical MRI. The presented imaging biomarkers can depict subtle changes after cartilage regeneration procedures and might help to understand gender related differences after cartilage repair procedures.

Comparison of synovial fluid, urine, and serum ion levels in metal-on-metal total hip arthroplasty at a minimum follow-up of 18 years.

Diagnosis of adverse reactions to metal debris in metal-on-metal hip arthroplasty is a multifactorial process. Systemic ion levels are just one factor in the evaluation and should not be relied upon solely to determine the need for revision surgery. Furthermore, the correlation between cobalt or chromium serum, urine, or synovial fluid levels and adverse local tissue reactions is still incompletely understood. The hypothesis was that elevated serum and urine metal-ion concentrations are associated with elevated local metal-ion concentrations in primary total hip arthroplasties (THA) and with failure of metal-on-metal articulations in the long-term. In our present study, we evaluated these concentrations in 105 cementless THA with metal-on-metal articulating surfaces with small head diameter at a minimum of 18 years postoperatively. Spearman correlation showed a high correlation between the joint fluid aspirate concentration of cobalt and chromium with the serum cobalt (r = 0.81) and chromium level (r = 0.77) in patients with the THA as the only source of metal-ions. In these patients serum metal-ion analysis is a valuable method for screening. In patients with more than one source of metal or renal insufficiency additional investigations, like joint aspirations are an important tool for evaluation of wear and adverse tissue reactions in metal-on-metal THA.

Treatment of Full-Thickness Chondral Defects With Hyalograft C in the Knee: Long-term Results.

BACKGROUND: Matrix-associated autologous chondrocyte transplantation (MACT) has become an established articular cartilage repair technique. It provides good short-term and midterm results; however, long-term results are lacking. PURPOSE: To prospectively assess the clinical outcome after MACT in the knee to report long-term results. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fifty-three subjects (females/males, 22/31; mean age, 32 ± 12 years) were treated between 2000 and 2006 with a hyaluronan-based MACT product and were followed prospectively. The mean body mass index (BMI) was 24.5 ± 3.8 kg/m(2) and the mean defect size was 4.4 ± 1.9 cm(2). Fifty patients had single defects and 3 had multiple defects (41 medial femoral condyle, 6 lateral femoral condyle, 2 patella, 1 tibia). Two patients had 2 defects (medial femoral condyle [MFC]/lateral femoral condyle and tibial/MFC), and in 1 case, multiple defects on the MFC were treated. The patients were stratified into 23 "simple," 22 "complex," and 8 "salvage" cases. Instability or malalignment was treated before or at the time of graft implantation. For 6 patients with small defects (<2 cm(2)), microfracturing was used as first-line treatment before MACT. Clinical assessment was performed once a year with the subjective and objective International Knee Documentation Committee (IKDC) scores, Lysholm score, and a modified Cincinnati Knee Rating System. RESULTS: The mean follow-up time was 9.07 ± 2.9 years (range, 5-12 years). Treatment failure occurred in 12 of 53 cases (22.6%) an average of 2.99 ± 1.40 years after surgery. There was 1 failure (4.3%) among the simple cases, 4 failures (18.2%) in complex cases, and 7 failures (87.5%) in salvage cases. Statistically significant increases were observed in all scores at all time points compared with presurgery levels (P < .05). The subjective IKDC score improved from median 40.4 preoperatively to 74.7 at 10-year follow-up (n = 13 patients; P < .05). CONCLUSION: MACT is an excellent surgical therapy for full-thickness cartilage defects of the knee, with good long-term results for simple defects. However, it should not be used in salvage cases.

Repair tissue quality after arthroscopic autologous collagen-induced chondrogenesis (ACIC) assessed via T2* mapping.

OBJECTIVE: A novel single-stage approach using arthroscopic microdrilling and atelocollagen/fibrin-gel application is employed for cartilage repair of the knee. The purpose of our study was to investigate the morphological and biochemical MRI outcome after this technique. MATERIALS AND METHODS: A retrospective case series of ten patients (mean age 45 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application was analyzed. All defects were ICRS grade III or IV and the sizes were 2-8 cm(2) intra-operatively. All patients underwent morphological MRI and T2-star mapping at 1.5 T at 1-year follow-up. The magnetic resonance observation of cartilage repair tissue (MOCART) score was assessed. T2* relaxation time values of repair tissue and a healthy native cartilage area was assessed by means of region of interest analysis on the T2* maps. RESULTS: The mean MOCART score at 1-year follow-up was 71.7 ± 21.0 ranging from 25 to 95. The mean T2* relaxation times were 30.6 ± 11.3 ms and 28.8 ± 6.8 ms for the repair tissue and surrounding native cartilage, respectively. The T2* ratio between the repair tissue and native cartilage was 105% ± 30%, indicating repair tissue properties similar to native cartilage. CONCLUSIONS: An arthroscopic single-stage procedure using microdrilling in combination with atelocollagen gel and fibrin-glue can provide satisfactory MRI results at 1-year follow-up, with good cartilage defect filling. The T2* values in the repair tissue achieved similar values compared to normal hyaline cartilage.

Autologous collagen-induced chondrogenesis: single-stage arthroscopic cartilage repair technique.

Autologous collagen-induced chondrogenesis is a novel, single-staged arthroscopic cartilage repair technique using microdrilling and atelocollagen or fibrin gel application under carbon dioxide insufflation. Atelocollagen is a highly purified type I collagen obtained following the treatment of skin dermis with pepsin and telopeptide removal, making it nonimmunogenic. In this procedure, atelocollagen mixed with fibrinogen and thrombin in a 2-way syringe can maintain the shape of the articular surface approximately 5 minutes after application due to the reaction between the thrombin and fibrinogen. Carbon dioxide insufflation facilitates the application of the gel under dry conditions. Ten patients (mean age, 38 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application were retrospectively analyzed. All defects were International Cartilage Repair Society grade III or IV and were 2 to 8 cm(2) in size intraoperatively. For the clinical assessment, Lysholm score was assessed preoperatively and at 2-year follow-up. All patients underwent morphological magnetic resonance imaging at 1.5-Tesla at 1-year follow-up. Mean Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score at 1-year follow-up was 70.4 ± 20.2 (range, 15-95). The Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score for patellar lesions was similar to that of lesions in other locations: 73.3 ± 11.7 vs 68.1 ± 25.5, respectively. This technique had encouraging clinical results at 2-year follow-up. Morphological magnetic resonance imaging shows good cartilage defect filling, and the biochemical magnetic resonance imaging suggests hyaline-like repair tissue.

Cartilage repair of the knee with Hyalograft C:® magnetic resonance imaging assessment of the glycosaminoglycan content at midterm.

PURPOSE: The aim of this study was to assess the stability of the glycosaminoglycan (GAG) content in the long term after matrix-associated autologous chondrocyte transplantation (MACT) with Hyalograft C in the knee over a follow-up period of one year. METHODS: In this cross-sectional evaluation, 11 patients after MACT of the knee consented to delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) measurements. The mean post-operative interval before the first MR examination was 40.6 ± 22.0 months, and the second MR examination was carried out after another 12 months. The Lysholm score was assessed for clinical evaluation. Quantitative T1 measurements after intravenous negatively charged MR contrast agent administration were performed. Global post-contrast T1 of the reference cartilage and the repair tissue and a relative post-contrast T1 value were calculated. RESULTS: The Lysholm score improved significantly from 59.8 ± 12.9 at baseline to 86.1 ± 15.7 at the second visit (p < 0.01). The mean global T1 of the repair tissue (1st visit 581.3 ± 126.4 ms; 2nd visit 684.1 ± 169.9 ms; p = 0.104) and the mean relative T1 value showed stable results over one year (1st visit 0.81 ± 0.28; 2nd visit 0.76 ± 0.32; p = 0.4). CONCLUSIONS: The study demonstrated stable glycosaminoglycan content of the repair tissue after MACT at midterm.

Can radiographic morphometric parameters for the hip be assessed on MRI?

BACKGROUND: Although morphometric hip parameters measured on radiographs are valuable tools guiding diagnosis and therapy in patients with hip disorders, some clinicians use MRI for such measurements, although it is unclear whether the parameters assessed on MRI differ from those assessed on radiographs. QUESTIONS/PURPOSES: We asked whether the lateral center-edge angle (LCE), Tönnis angle, extrusion index, and anterior center-edge angle (ACE) are similar on MRI and radiography. METHODS: We retrospectively reviewed the imaging data of 103 hips from 103 patients: 46 with femoroacetabular impingement and 57 with hip dysplasia. We manually measured the LCE, Tönnis angle, extrusion index, and ACE from radiographs and MRI in all 103 hips. Four straight coronal (Ant-10 mm, Ant-5 mm, Center, and Post-5 mm), three straight sagittal (S-Med-5 mm, S-Center, S-Lat-5 mm), and three 25º oblique sagittal (OS-Med-5 mm, OS-Center, OS-Lat-5 mm) reformats were reconstructed from a three-dimensional isotropic morphologic MRI sequence. MRI measurements were compared against the gold standard radiographic measurements. RESULTS: We found good agreement for the LCE angle, Tönnis angle, and extrusion index between radiographic and coronal slice MRI measurements. The mean differences between radiographic and MRI measurements were 5º or less or 5% or less (for the extrusion index) in all coronal MRI slices. However, the differences between ACE angles on sagittal MRI slices and radiographs ranged from 5° to 28º. CONCLUSIONS: LCE, Tönnis angle, and extrusion index can be measured on MRI with comparable results to radiography. The ACE angle on radiographs cannot be estimated reliably from MRI. CLINICAL RELEVANCE: MRI provides similar morphometric measurements as radiography for most hip parameters, except for the ACE angle.