Evaluation of Open Versus Arthroscopic Anterior Talofibular Ligament Reconstruction for Chronic Lateral Ankle Instability With Talar and Subtalar Cartilage MRI T2 Mapping: A 3-Year Prospective Study.

BACKGROUND: Previous studies have examined patients with chronic lateral ankle instability (CLAI) undergoing open and arthroscopic anterior talofibular ligament (ATFL) reconstruction, reporting equivalent clinical results between the 2 procedures. However, data on the magnetic resonance imaging (MRI) outcomes on cartilage health after the 2 procedures are limited. PURPOSE: To compare the cartilage MRI T2 values of the talar and subtalar joints between patients with CLAI undergoing open and arthroscopic ATFL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A prospective study was conducted on patients who underwent open or arthroscopic ATFL reconstruction between January 2018 and December 2019, with a mean follow-up duration of 3 years. MRI scans and American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner score estimations were completed by patients ≤1 week before surgery, as a baseline measurement, and at a 3-year follow-up. A total of 21 healthy volunteers were included who underwent MRI at baseline. Cartilage health was evaluated using MRI T2 mapping. The talar and subtalar cartilage regions were segmented into 14 subregions. RESULTS: At baseline, patients with CLAI had substantially higher T2 values in the medial anterior, medial center, medial posterior, and lateral center regions on the talus compared with the healthy controls (P = .009, .003, .001, and .025, respectively). Remarkable increases in T2 values in the lateral posterior region on the talus were observed from baseline to follow-up in the open group (P = .007). Furthermore, T2 values were considerably higher in the medial center, medial posterior, lateral posterior, and lateral posterior calcaneal facets of the posterior subtalar joint at follow-up in the arthroscopic group compared with the baseline values (P = .025, .002, .006, and .044, respectively). No obvious differences in ΔT2 values were noted between the 2 groups at follow-up. The AOFAS and Tegner scores remarkably improved from baseline to follow-up for the 2 groups (open: 3.25 ± 0.58 vs 5.13 ± 0.81, P < .001; arthroscopic: 3.11 ± 0.90 vs 5.11 ± 1.08, P < .001), with no considerable difference between them. CONCLUSION: The elevated T2 values of cartilage could not be fully recovered after open or arthroscopic ATFL reconstruction. Both arthroscopic and open ATFL reconstruction displayed similar effects on cartilage health concerning ΔT2, but the arthroscopic group demonstrated more degenerative cartilage subregions than the open group.

More severe supraspinatus tendon degeneration on the contralateral shoulders in patients treated for symptomatic rotator cuff tears compared to healthy controls: a quantitative MRI-based study.

BACKGROUND: Patients treated for symptomatic rotator cuff tear (RCT) on one shoulder seem to have a higher prevalence of RCT on the contralateral shoulder. PURPOSE: To compare the supraspinatus (SSP) tendon and RC muscle properties on the contralateral shoulder in patients after repair surgery to those healthy individuals using quantitative magnetic resonance imaging (MRI). MATERIAL AND METHODS: A total of 23 patients treated for RCT (group A) and 23 healthy controls (group B) were recruited. Constant score, visual analog scale score (VAS), and MRI examinations were conducted. The SSP tendon structural status was graded based on the Zlatkin classification and quantified on ultrashort echo time (UTE)-T2* mapping images. Fatty degeneration of RC muscles was classified according to the Goutallier classification and quantified on T2 mapping. RESULTS: The Constant and VAS scores were comparable between groups A and B (all P >0.05). No significant differences were observed in tendon structural status between the two groups (P >0.05). However, significant differences were established in UTE-T2* values of the SSP tendon on the distal subregion between groups A and B (16.4 ± 2.4 ms vs. 14.8 ± 1.2 ms; P = 0.01). Regarding muscle degeneration, no significant differences were displayed in T2 values and Goutallier classification of RC muscles (all P >0.05). CONCLUSION: Patients with a treated RCT demonstrated inferior SSP tendon in the distal subregion on the contralateral shoulders one year postoperatively compared to that of healthy controls based on quantitative MRI data.

Satisfactory outcomes from the double-row fixation procedure for ankle lateral ligaments injury with os subfibulare.

Background: Ossicles of avulsed fractures of the lateral malleolus can result in pain or chronic ankle instability. The purpose of this study was to evaluate and compare the arthroscopic double-row fixation procedure with anatomic ankle lateral ligaments reconstruction for the treatment of ankle lateral ligaments injury with os subfibulare. Methods: This retrospective study included 38 patients with ankle lateral ligaments injury with concomitant os subfibulare who were treated between July 2016 and November 2021. The patients were divided into a double-row fixation group (n = 19) and an ankle lateral ligaments reconstruction group (n = 19). The Karlsson and Peterson Scoring System for Ankle Function (KAFS), American Orthopedic Foot and Ankle Society (AOFAS) score, Tegner score, visual analog scale (VAS), and anterior drawer test (ADT) were obtained preoperatively and at the last post-operative follow-up. Magnetic resonance imaging (MRI) was also performed at the last post-operative follow-up. Results: The KAFS, AOFAS, VAS, and Tegner scores increased significantly after the surgery. Furthermore, the pre- and post-operative functional scores were comparable between the two groups. The ADT was negative in all participants post-operatively. There were no significant differences between the double-row fixation and ligaments reconstruction groups regarding the proportions of patients who achieved a minimally clinically important difference (MCID) in KAFS, AOFAS, and Tegner scores. There was no significant difference in T2 mapping values for the tibial and talar side post-operatively between the two groups. Moreover, there were no significant differences in functional scores post-operatively between bony fusion and non-fusion patients in the double fixation group. Conclusion: The double-row fixation procedure provided similar satisfactory clinical outcomes when compared with lateral ligaments reconstruction for the treatment of ankle lateral ligaments injury with os subfibulare over a short follow-up duration.

T2*-corrected Q-Dixon and reduced-FOV diffusion kurtosis imaging (DKI) parameters: correlation with QCT-derived bone mineral density (BMD) and ability to identify abnormal BMD and osteoporosis in postmenopausal women.

Background: Bone marrow fat increases when the bone volume decreases. The composition of the bone marrow microenvironment can also become altered. Assessments of bone marrow fat and bone marrow structural heterogeneity have the potential to predict abnormal bone mineral density (BMD) and osteoporosis. This study aimed to investigate the diagnostic performance of T2*-corrected Q-Dixon and reduced-field-of-view (FOV) diffusion kurtosis imaging (DKI) parameters in determining abnormal BMD and osteoporosis in postmenopausal women. Methods: In this prospective study, the individuals who were eligible for inclusion included postmenopausal women (over 50-year-old) with suspected osteoporosis based on experiencing low back pain. This mono-center study was conducted in tertiary care in China. All of the patients were recruited by using the consecutive sampling method. Subjects who underwent T2*-corrected Q-Dixon and reduced-FOV DKI sequences were enrolled. Fat fraction (FF), T2*, mean kurtosis (MK), and mean diffusivity (MD) values were measured on L1, L2, and L3 vertebral bodies. Quantitative computed tomography (QCT) examinations served as the reference standard. All of the subjects were divided into three groups: normal (BMD >120 mg/cm3), osteopenia (BMD 80-120 mg/cm3), and osteoporosis (BMD <80 mg/cm3). One-way analysis of variance, correlation coefficient analysis, and receiver operating characteristic curve analysis were performed. Results: Among all of the enrolled subjects, 52 were in the normal group, 51 were in the osteopenia group, and 52 were in the osteoporosis group. There were significant differences in FF, T2*, MK, and MD values between the three groups (P<0.001, P<0.001, P<0.001, and P=0.003, respectively). FF, T2*, and MK values exhibited significant negative correlations with BMD values (r=-0.739, P<0.001; r=-0,676, P<0.001; and r=-0.626, P<0.001, respectively). Excellent discriminatory capacity was observed in the Q-Dixon [area under the curve (AUC): 0.976, 95% confidence interval (CI): 0.955-0.997] differentiation between normal and abnormal BMD subjects. It was significantly better than the DKI (AUC: 0.812, 95% CI: 0.741-0.882) parameter combination (P<0.001), whereas the DKI model (AUC: 0.825, 95% CI: 0.739-0.910) performed comparably to the Q-Dixon model (AUC: 0.798, 95% CI: 0.710-0.886) for screening osteoporosis (P=0.57). Conclusions: FF and T2* values measured by using T2*-corrected Q-Dixon, as well as MK and MD values measured by using reduced-FOV DKI, may serve as potential imaging biomarkers in assessing abnormal BMD and osteoporosis in postmenopausal women.

Whole-tumor histogram analysis of diffusion-weighted imaging and dynamic contrast-enhanced MRI for soft tissue sarcoma: correlation with HIF-1alpha expression.

OBJECTIVE: To investigate the correlation of histogram metrics from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters with HIF-1alpha expression in soft tissue sarcoma (STS). METHODS: We enrolled 71 patients with STS who underwent 3.0-T MRI, including conventional MRI, DWI, and DCE-MRI sequences. Location, maximum tumor diameter, envelope, T2-weighted tumor heterogeneity, peritumoral edema, peritumoral enhancement, necrosis, tail-like pattern, bone invasion, and vessel/nerve invasion and/or encasement were determined using conventional MRI images. The whole-tumor histogram metrics were calculated on the apparent diffusion coefficient (ADC), Ktrans, Kep, and Ve maps. Independent-samples t test and one-way ANOVA were used for testing the differences between normally distributed categorical data with HIF-1alpha expression. Pearson and Spearman correlations and multiple linear regression analyses were performed to determine the correlations between histogram metrics and HIF-1alpha expression. Survival curves were plotted using the Kaplan-Meier method. RESULTS: Regarding conventional MRI features, only highly heterogeneous on T2-weighted images (55.6 ± 19.9% vs. 45.4 ± 20.5%, p = 0.041) and more than 50% necrotic area (57.3 ± 20.4% vs. 43.9 ± 19.7%, p = 0.002) were prone to indicate STS with higher HIF-1alpha expression. Histogram metrics obtained from ADC (mean, median, 10th, and 25th percentile values), Ktrans (mean, median, 75th, and 90th percentile values), and Kep (90th percentile values) were significantly correlated with HIF-1alpha expression. Multiple linear regression analysis demonstrated that more than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression. CONCLUSION: DWI and DCE-MRI histogram parameters were significantly correlated with HIF-1alpha expression in STS. KEY POINTS: • DWI and DCE-MRI histogram parameters are correlated with HIF-1alpha expression in STS. • More than 50% necrosis, ADCskewness, Ktrans90th, and grade III were independently associated with HIF-1alpha expression in STS.

Soft tissue sarcoma: correlation of dynamic contrast-enhanced magnetic resonance imaging features with HIF-1α expression and patient outcomes.

Background: To investigate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features for predicting hypoxia-inducible factor 1-alpha (HIF-1α) expression and patient outcomes in soft tissue sarcoma (STS). Methods: We enrolled 71 patients with STS who underwent 3.0 Tesla (3.0T) MRI, including conventional MRI and DCE-MRI sequencing. The location, maximum tumor diameter, envelope, T2-weighted tumor heterogeneity, peritumoral edema, peritumoral enhancement, necrosis, configuration, tail-like pattern, bone invasion, and vessel/nerve invasion and/or encasement of the STSs were determined using conventional MRI images. The DCE-MRI parameters, including the volume transfer constant (Ktrans ), reflux rate (Kep ), volume fraction of extravascular extracellular matrix (Ve ), and time-signal intensity curve (TIC) type, of each lesion were independently analyzed by two observers. Independent samples t-test, chi-square test, and Mann-Whitney U-test were performed to evaluate the differences in the MRI features between the two groups. The relationships between the DCE-MRI parameters and HIF-1α expression were analyzed using Spearman's correlation analysis. The Cox proportional hazards model and Kaplan-Meier method were used for survival analysis. Results: Of the conventional MRI features, high heterogeneity, peritumoral enhancement, necrosis, and multilobulation of the T2-weighted tumor were prone to occur in the high-expression group. Of the DCE-MRI parameters, the high-expression group showed significantly higher Ktrans (0.311±0.091 vs. 0.210±0.058 min-1), and Kep values (0.896±0.656 vs. 0.444±0.300 min-1) than the low-expression group. No significant differences in TIC types and Ve values were observed between the low- and high-expression groups (P>0.05). There were positive correlations between Ktrans and Kep values with HIF-1α expression (r=0.705, P<0.001; r=0.123, P<0.001, respectively). Receiver operating characteristic (ROC) analysis indicated high specificity (93.9%) of the Ktrans value for predicting high expression of HIF-1α. The Kep value provided the best performance in diagnostic sensitivity (84.2%). Survival analyses revealed that more than 50% necrosis, multilobulation, and Ktrans values greater than 0.262 min-1 were strongly associated with a higher risk of death. Conclusions: Conventional MRI features and DCE-MRI parameters were significantly helpful in determining HIF-1α expression levels and predicting the overall survival (OS) of patients with STS.

Cartilage Matrix Changes in Hindfoot Joints in Chronic Ankle Instability Patients After Anatomic Repair Using T2-Mapping: Initial Experience With 3-Year Follow-Up.

BACKGROUND: Anatomic repair is widely accepted as the primary surgical treatment for chronic lateral ankle instability (CLAI). T2-mapping is a powerful tool for quantitative assessment of biochemical changes in cartilage matrix. PURPOSE: To longitudinally evaluate cartilage matrix changes in the hindfoot joints of CLAI patients before and after anatomic repair by using T2-mapping with magnetic resonance imaging (MRI). STUDY TYPE: Prospective. SUBJECTS: Thirty-two CLAI patients (males/females = 20/12) and 21 healthy controls (males/females = 13/7). FIELD STRENGTH/SEQUENCE: 3 T; sagittal multi-echo spin-echo technique (T2-mapping), coronal, sagittal, and axial spin-echo PD-FS, and sagittal T1WI sequences. ASSESSMENT: MRI examinations were performed in CLAI patients at baseline (prior to surgery) and 3 years after anatomic repair and in healthy controls. On T2-maps, the hindfoot joints were segmented into 16 cartilage subregions. The T2 value of each subregion was measured. All patients were evaluated with the American Orthopedic Foot and Ankle Society (AOFAS) scale at baseline and after surgery. STATISTICAL TESTS: Analysis of variance (ANOVA) and Student's t-test were used. The differences corresponding to P < 0.05 were considered statistically significant. RESULTS: At baseline, the T2 values in most cartilage subregions of talar dome and medial posterior subtalar joint (pSTJ) were higher in CLAI patients than in healthy controls. After surgery, only the T2 value of anteriomedial talar dome decreased from that at baseline (31.11 ± 3.88 msec vs. 34.27 ± 5.30 msec). The T2 values of other subregions with elevated T2 values remained higher than healthy controls. There were no significant differences in T2 values in the midtarsal joints between CLAI patients and healthy controls (P = 0.262, 0.104, 0.169, 0.103). Postoperatively, the patients' AOFAS scores improved significantly from 67.81 to 89.13. DATA CONCLUSION: CLAI patients exhibited elevated T2 values in most subregions of talar dome and medial pSTJ. After anatomic repair, although the patients exhibited good clinical outcomes, the elevated T2 values could not be fully recovered. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 4.

Outcomes of arthroscopic bone graft transplantation for Hepple stage V osteochondral lesions of the talus.

BACKGROUND: Based on MRI imaging findings, osteochondral lesions of the talus (OLT) can be classified into five stages, in which stage V represents OLT with subchondral cyst formation. The aim of this study was to evaluate the outcomes of patients undergoing arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT. METHODS: This retrospective study included 24 patients with Hepple stage V OLT (15 men and 9 women), with an average age of 39.8±12.9 years old. The mean follow-up period was 18.9±11.8 months. At this follow-up, all patients were clinically evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Karlsson Ankle Function Score (KAFS), the Tegner score, and the visual analogue scale (VAS). Furthermore, 14 patients underwent MRI imaging examinations, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score was assessed. RESULTS: The AOFAS score, KAFS, Tegner activity score, and VAS pain score (preoperative: 62.2, 60.4, 2.1, and 6.2, respectively; postoperative: 92.8, 88.5, 4.2, and 1.6, respectively) improved significantly (P=0.0001). The MRI-based MOCART score of the articular cartilage repair tissue after surgery was 68±14.8. CONCLUSIONS: Arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT could obtain satisfying clinical and radiological outcomes in the short-term.

Magnetic Resonance Imaging T2* Mapping of the Talar Dome and Subtalar Joint Cartilage 3 Years After Anterior Talofibular Ligament Repair or Reconstruction in Chronic Lateral Ankle Instability.

BACKGROUND: Cartilage degeneration is a common issue in patients with chronic lateral ankle instability. However, there are limited studies regarding the effectiveness of lateral ligament surgery on preventing talar and subtalar joint cartilage from further degenerative changes. PURPOSE: To longitudinally evaluate talar and subtalar cartilage compositional changes using magnetic resonance imaging T2* mapping in anatomic anterior talofibular ligament (ATFL)-repaired and ATFL-reconstructed ankles and to compare them with measures in asymptomatic controls. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between January 2015 and December 2016, patients with chronic lateral ankle instability who underwent anatomic ATFL repair (n = 19) and reconstruction (n = 20) were prospectively recruited. Patients underwent 3.0-T magnetic resonance imaging at baseline and 3-year follow-up. As asymptomatic controls, 21 healthy volunteers were recruited and underwent imaging at baseline. Talar dome cartilage was divided into (1) medial anterior, central, and posterior and (2) lateral anterior, central, and posterior. Posterior subtalar cartilage was divided into (1) central talus and calcaneus and (2) lateral talus and calcaneus. Ankle function was assessed using the American Orthopaedic Foot & Ankle Society scores. RESULTS: There were significant increases in T2* values in medial and lateral posterior and central talus cartilage from baseline to 3-year follow-up in patients who underwent repair. T2* values were significantly higher in ATFL-repaired ankles at follow-up for all cartilage regions of interest, except medial and lateral anterior and lateral central, compared with those in healthy controls. From baseline to 3-year follow-up, ATFL-reconstructed ankles had a significant increase in T2* values in lateral central and posterior cartilage. T2* values in ATFL-reconstructed ankles at follow-up were elevated in all cartilage regions of interest, except medial and lateral anterior, compared with those in healthy controls. ATFL-repaired ankles showed a greater decrease of T2* values from baseline to follow-up in lateral calcaneus cartilage than did ATFL-reconstructed ankles (P = .031). No significant differences in American Orthopaedic Foot & Ankle Society score were found between repair and reconstruction procedures (mean ± SD, 19.11 ± 7.45 vs 16.85 ± 6.24; P = .311). CONCLUSION: Neither anatomic ATFL repair nor reconstruction could prevent the progression of talar dome and posterior subtalar cartilage degeneration; however, ankle function and activity levels were not affected over a short period. Patients who underwent ATFL repair exhibited lower T2* values in the lateral calcaneus cartilage than did those who underwent reconstruction.

Disturbances in Metabolic Pathways and the Identification of a Potential Biomarker Panel for Early Cartilage Degeneration in a Rabbit Anterior Cruciate Ligament Transection Model.

OBJECTIVE: This study aimed to assess the association between synovial fluid (SF) metabolites and magnetic resonance imaging (MRI) measurements of cartilage biochemical composition to identify potential SF biomarkers for detecting the early onset of cartilage degeneration in a rabbit model. METHODS: Both knees of 12 New Zealand White rabbits were used. The anterior cruciate ligament transection (ACLT) model was performed on right knees, and the sham surgery on left knees. MRI UTE-T2* scanning and SF sample collection were performed on ACLT knees at 4 and 8 weeks postsurgery and on sham surgery knees at 4 weeks postsurgery. Ultra-performance liquid chromatography-mass spectrometry and multivariate statistical analysis were used to distinguish samples in three groups. Pathway and receiver operating characteristic analyses were utilized to identify potential metabolite biomarkers. RESULTS: There were 12 knees in sham surgery models, 11 in ACLT models at 4 weeks postsurgery, and 10 in ACLT models at 8 weeks postsurgery. UTE-T2* values for the lateral tibia cartilage showed significant decreases over the study period. Levels of 103 identified metabolites in SF were markedly different among three groups. Furthermore, 24 metabolites were inversely correlated with UTE-T2* values of the lateral tibia cartilage, while hippuric acid was positively correlated with UTE-T2* values of the lateral tibia cartilage. Among 25 potential markers, N1-acetylspermidine, 2-amino-1,3,4-octadecanetriol, l-phenylalanine, 5-hydroxy-l-tryptophan, and l-tryptophan were identified as potential biomarkers with high area under the curve values and Pearson correlation coefficients. CONCLUSION: Five differential metabolites in SF were found as potential biomarkers for the early detection of cartilage degeneration in the rabbit ACLT model.

Quantitative T2 mapping-based tendon healing is related to the clinical outcomes during the first year after arthroscopic rotator cuff repair.

PURPOSE: The objective of this study was to determine the correlation between quantitative T2 mapping-based tendon healing and clinical outcomes during the first year after arthroscopic rotator cuff repair. METHODS: Twenty-two patients with rotator cuff tear were prospectively recruited. Serial clinical and MRI follow-up assessments were carried out at 1 month, 6 months and 12 months after surgery. Twenty healthy volunteers were involved and were examined with clinical and MRI assessments. Clinical assessments included Constant Score (CS), the American Shoulder and Elbow Surgeons (ASES), the modified University of California, Los Angles (UCLA) scores and Visual Analog Scale (VAS). The region of interest of tendon healing was defined directly over the medial suture anchor on T2 mapping. Spearman correlation coefficient was used to analyze the correlations between MRI measurements and clinical outcomes. RESULTS: All clinical scores indicated significant improvements over the postoperative observation period compared with the initial preoperative values (all P < 0.001). At 12 months, all of the patients returned to their daily life activities. The T2 values of the healing site significantly decreased over time (P < 0.001) and were comparable to those of healthy tendons at 12 months (n.s.). Additionally, the T2 values were negatively correlated with CS (r = - 0.5, P < 0.001), ASES (r = - 0.5, P < 0.001), and UCLA (r = - 0.5, P < 0.001); and positively correlated with VAS score (r = 0.4, P < 0.001). No significant correlations were found between Sugaya classification and clinical scores (all n.s.). CONCLUSIONS: With regard to tendon healing during the first follow-up year, the T2 values of the healing site decreased with the improvement of clinical outcomes over time. LEVEL OF EVIDENCE: II.

Quantitative Magnetic Resonance Imaging UTE-T2* Mapping of Tendon Healing After Arthroscopic Rotator Cuff Repair: A Longitudinal Study.

BACKGROUND: Quantitative ultrashort echo time-T2* (UTE-T2*) mapping shows promise for the detection of potential tendon biochemical conditions, while validation against established clinical studies in the shoulder is needed. PURPOSE: To evaluate and characterize the healing process of the repaired rotator cuff based on longitudinal changes in UTE-T2* values, clinical outcomes, and repair status in patients after arthroscopic rotator cuff repair (ARCR). STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients with ARCR (n = 25) underwent quantitative MRI and clinical examinations at serial follow-up time points: 3, 6, 12, and 24 months postoperatively. Age-matched healthy controls (n = 15) were evaluated at 3 and 12 months after enrollment. Clinical scores included the Constant, American Shoulder and Elbow Surgeons, and Fudan University Shoulder score, and visual analog scale for pain. The MRI examination included UTE-T2*mapping. UTE-T2* maps were generated for T2* values at the healing site. Sugaya classification was adopted to evaluate the repair status. Longitudinal analyses of clinical outcomes, UTE-T2* changes, and Sugaya classification were conducted. RESULTS: The overall retear rate was 8% (2/25, all Sugaya type IV). All patients (including the ones with retear) achieved satisfactory outcomes at 12 months that lasted to 24 months on the basis of clinical scores. The mean UTE-T2* values at the healing site showed an increase from 3 to 6 months (P = .03) and then decreased to a level similar to that observed in age-matched healthy tendons at 12 months (P = .1). No significant differences were found between UTE-T2* values at 12 and 24 months (P = .6). UTE-T2* values at the healing site significantly varied with the repair status according to Sugaya classification (P < .05). Moreover, significant correlations were noted between clinical scores and UTE-T2* values at 6 months (r = -0.6 to -0.3; all P < .05) and 12 months (r = -0.6 to -0.2; all P < .05). CONCLUSION: This study indicated a healing-related relationship between clinical outcomes and quantitative UTE-T2* values, which highlights the potential of using UTE-T2* mapping to track the tendon-healing process noninvasively. Moreover, the repaired tendon was comparable to age-matched healthy controls at 12-month follow-up based on UTE-T2* values.

Controlled-releasing hydrogen sulfide donor based on dual-modal iron oxide nanoparticles protects myocardial tissue from ischemia-reperfusion injury.

BACKGROUND: Hydrogen sulfide (H2S) has shown promising therapeutic benefits in reversing a variety of pathophysiological processes in cardiovascular system, including myocardial ischemia-reperfusion (IR) injury. However, the achievement of controlled and sustained release of H2S has been a technical bottleneck that limits the clinical application of the gas molecule. METHODS: The current study describes the development of mesoporous iron oxide nanoparticles (MIONs) which were loaded with diallyl trisulfide (DATS), a H2S donor compound, and calibrated by stimulated Raman scattering/transient absorption. RESULTS: The synthesized MIONs were characterized with excellent mesoporosity and a narrow size distribution, which enabled them to slow down the release of H2S to a suitable rate and prolong the plateau period. The controlled-release feature of DATS-MIONs resulted in little adverse effect both in vitro and in vivo, and their protective effect on the heart tissue that underwent IR injury was observed in the mouse model of myocardial ischemia. The rapid biodegradation of DATS-MIONs was induced by Kupffer cells, which were specialized macrophages located in the liver and caused limited hepatic metabolic burden. CONCLUSION: The sustained-release pattern and excellent biocompatibility make DATS-MIONs a promising H2S donor for research and medical purposes.

Engineering human ventricular heart tissue based on macroporous iron oxide scaffolds.

Myocardial infarction (MI) is a primary cardiovascular disease threatening human health and quality of life worldwide. The development of engineered heart tissues (EHTs) as a transplantable artificial myocardium provides a promising therapy for MI. Since most MIs occur at the ventricle, engineering ventricular-specific myocardium is therefore more desirable for future applications. Here, by combining a new macroporous 3D iron oxide scaffold (IOS) with a fixed ratio of human pluripotent stem cell (hPSC)-derived ventricular-specific cardiomyocytes and human umbilical cord-derived mesenchymal stem cells, we constructed a new type of engineered human ventricular-specific heart tissue (EhVHT). The EhVHT promoted expression of cardiac-specific genes, ion exchange, and exhibited a better Ca2+ handling behaviors and normal electrophysiological activity in vitro. Furthermore, when patched on the infarcted area, the EhVHT effectively promoted repair of heart tissues in vivo and facilitated the restoration of damaged heart function of rats with acute MI. Our results show that it is feasible to generate functional human ventricular heart tissue based on hPSC-derived ventricular myocytes for the treatment of ventricular-specific myocardium damage. STATEMENT OF SIGNIFICANCE: We successfully generated highly purified homogenous human ventricular myocytes and developed a method to generate human ventricular-specific heart tissue (EhVHT) based on three-dimensional iron oxide scaffolds. The EhVHT promoted expression of cardiac-specific genes, ion exchange, and exhibited a better Ca2+ handling behaviors and normal electrophysiological activity in vitro. Patching the EhVHT on the infarct area significantly improved cardiac function in rat acute MI models. This EhVHT has a great potential to meet the specific requirements for ventricular damages in most MI cases and for screening drugs specifically targeting ventricular myocardium.

Time From Injury to Surgery Affects Graft Maturation Following Posterior Cruciate Ligament Reconstruction With Remnant Preservation: A Magnetic Resonance Imaging-Based Study.

PURPOSE: To evaluate the clinical outcomes and graft maturation following posterior cruciate ligament reconstruction (PCLR) with preserved remnant and further analyze the correlated factors affecting graft maturation. METHODS: Consecutive patients who underwent unilateral single-bundle PCLR with remnant preservation from January 2011 to October 2014 by the same senior doctor using tibialis anterior allografts and same surgical technique were included. At a follow-up of more than 2 years, range of motion (ROM) and posterior laxity assessed by posterior drawer test and the KT-1000 arthrometer were examined. Tegner, Lysholm, and International Knee Documentation Committee scores were evaluated. The graft maturation was assessed by a 3.0-T magnetic resonance imaging. Overall correlation analyses and multivariate regression analysis were performed to identify correlated factors of graft maturation, and then subgroups were divided and analyzed according to significant risk factor. RESULTS: Forty-three (84.3%) of 51 enrolled patients were successfully followed up (38.4 months, 24-54 months). All clinical scores improved significantly, and there were no complications. The results of KT-1000 difference revealed significant decline of posterior laxity (9.4 ± 1.5 vs 2.2 ± 1.5 mm; P < .001). The MRI evaluation confirmed no ligament retears. Both correlation and regression analyses showed time from injury to surgery had a positive, statistically significant weak correlation with the signal intensity score (R = 0.38, P = .012; coefficient = 0.10; P = .036). Subgroup (group 1: time from injury to surgery <3 months; group 2: 3-6 months; group 3: 6-12 months; group 4: ≥12 months) analysis showed there were no significant differences of clinical outcomes between subgroups, while MRI signal intensity was significantly lower in the group with shorter time from injury to surgery (P = .02). CONCLUSIONS: The remnant-preserved PCLR resulted in satisfactory clinical outcomes and graft maturation at a mean follow-up of 38.4 months. The time from injury to surgery showed a weak positive correlation with postoperative graft signal intensity on MRI. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Clinical and magnetic resonance imaging assessment of anatomical lateral ankle ligament reconstruction: comparison of tendon allograft and autograft.

PURPOSE: To compare the results of anatomical lateral ankle ligament (LAL) reconstruction with tendon allograft and autograft using clinical scores and ultrashort echo time (UTE) sequence of MRI. METHODS: A total of 26 patients with LAL reconstruction were recruited in this study, including 16 using semitendinosus allografts and 10 using semitendinosus autograft. All of them were diagnosed as chronic ankle instability and accepted anatomic reconstruction. The American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, and radiological evaluation using MRI UTE scanning were extracted from each patient. The comparative analysis of the clinical assessments and UTE-T2* values were performed between the patients using autografts and allografts. RESULTS: For the allograft group, the mean AOFAS score improved from 69.9 ± 13.3 to 94.8 ± 5.4 (P = 0.000), and the mean Karlsson score improved from 70.3 ± 12.2 to 93.8 ± 5.6 (P = 0.000). For the autograft group, the mean AOFAS score improved from 68.4 ± 10.0 to 94.7 ± 5.0 (P = 0.000), and the mean Karlsson score improved from 64.5 ± 14.4 to 95.0 ± 5.8 (P = 0.000). No significant differences were found between the allograft and autograft neither before (AOFAS P = 0.756, Karlsson P = 0.285) nor after (AOFAS P = 0.957, Karlsson P = 0.574) surgery. While the UTE T2* values in allograft were higher than those of autograft group both in anterior talofibular ligament (8.3 ± 1.0 vs 7.6 ± 1.1 P = 0.027) and intra-tunnel graft (7.8 ± 0.6 vs 7.2 ± 0.8 P = 0.045). CONCLUSION: Both allograft and autograft reconstructions could get an ideal patient satisfaction and clinical functional outcomes at the follow-up. Higher T2* values were found in allograft group which indicated that autograft had some superiorities in respect of revascularization process, collagen structure, water content, and tendon properties.

Implantable and Biodegradable Macroporous Iron Oxide Frameworks for Efficient Regeneration and Repair of Infracted Heart.

The construction, characterization and surgical application of a multilayered iron oxide-based macroporous composite framework were reported in this study. The framework consisted of a highly porous iron oxide core, a gelatin-based hydrogel intermediary layer and a matrigel outer cover, which conferred a multitude of desirable properties including excellent biocompatibility, improved mechanical strength and controlled biodegradability. The large pore sizes and high extent of pore interconnectivity of the framework stimulated robust neovascularization and resulted in substantially better cell viability and proliferation as a result of improved transport efficiency for oxygen and nutrients. In addition, rat models with myocardial infraction showed sustained heart tissue regeneration over the infract region and significant improvement of cardiac functions following the surgical implantation of the framework. These results demonstrated that the current framework might hold great potential for cardiac repair in patients with myocardial infraction.

A Strategy for Precise Treatment of Cardiac Malignant Neoplasms.

The prevalence of cardiac malignant neoplasms in the general population has been shown to be significant higher than what was previously estimated, yet their treatment has remained difficult and effective therapies are lacking. In the current study, we developed a novel thermotherapy in which PEG-functionalized carbon nanotubes were injected into the tumor regions to assist in the targeted delivery of infrared radiation energy with minimal hyperthermic damage to the surrounding normal tissues. In a mouse model of cardiac malignant neoplasms, the injected carbon nanotubes could rapidly induce coagulative necrosis of tumor tissues when exposed to infrared irradiation. In accordance, the treatment was also found to result in a restoration of heart functions and a concomitant increase of survival rate in mice. Taken together, our carbon nanotube-based thermotherapy successfully addressed the difficulty facing conventional laser ablation methods with regard to off-target thermal injury, and could pave the way for the development of more effective therapies against cardiac malignant neoplasms.

Clinical and MRI outcomes of HA injection following arthroscopic microfracture for osteochondral lesions of the talus.

PURPOSE: The purpose of this study was to compare the clinical and magnetic resonance imaging (MRI) outcomes of arthroscopic microfracture surgery alone or in combination with hyaluronic acid (HA) injection in the treatment of osteochondral lesions of the talus. METHODS: Thirty-five patients with osteochondral lesions of the talus who underwent arthroscopic microfracture were included and followed up for at least 9 months post-operatively. The patients were randomly divided into non-injection group (n = 17) who received treatment with microfracture surgery alone and injection group (n = 18) who also accepted intra-articular injection of HA post-operatively. Quantitative MRI was used to evaluate the cartilage repair after surgery. American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hind foot Scale scores and Visual Analogue Scale (VAS) scores were used to evaluate clinical outcomes. RESULTS: After operation, the MRI outcomes showed that the thickness index was higher (0.8 ± 0.1 vs. 0.7 ± 0.1) and the T2 index was lower (1.2 ± 0.1 vs. 1.4 ± 0.1) in the injection group than in the non-injection group (P < 0.01). As for the volumes of subchondral bone marrow oedema, there are no significant differences between groups (n.s.). Compared with the non-injection group, the AOFAS score and the VAS score yielded a higher level of improvement in injection group at final follow-up post-operatively (P < 0.05). CONCLUSIONS: Arthroscopic microfracture is a safe and effective procedure for osteochondral lesions of the talus. Intra-articular HA injection as an adjunct to arthroscopic microfracture might offer better functional recovery than microfracture alone. LEVEL OF EVIDENCE: II.