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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. [ABSTRACT FROM AUTHOR]

Abstract Background To compare potential of ultrashort time-to-echo (UTE) T2* mapping and T2* values from T2*-weighted imaging for assessing lumbar intervertebral disc degeneration (IVDD),with Pfirrmann grading as a reference standard. Methods UTE-T2* and T2* values of 366 lumbar discs (L1/2-L5/S1) in 76 subjects were measured in 3 segmented regions: anterior annulus fibrosus, nucleus pulposus (NP), and posterior annulus fibrosus. Lumbar intervertebral discs were divided into 3 categories based on 5-level Pfirrmann grading: normal (Pfirrmann grade I),early disc degeneration (Pfirrmann grades II-III), and advanced disc degeneration (Pfirrmann grades IV-V). Regional differences between UTE-T2* and T2* relaxometry and correlation with degeneration were statistically analyzed. Results UTE-T2* and T2*value correlated negatively with Pfirrmann grades (P

Background: To compare potential of ultrashort time-to-echo (UTE) T2* mapping and T2* values from T2*-weighted imaging for assessing lumbar intervertebral disc degeneration (IVDD),with Pfirrmann grading as a reference standard.Methods: UTE-T2* and T2* values of 366 lumbar discs (L1/2-L5/S1) in 76 subjects were measured in 3 segmented regions: anterior annulus fibrosus, nucleus pulposus (NP), and posterior annulus fibrosus. Lumbar intervertebral discs were divided into 3 categories based on 5-level Pfirrmann grading: normal (Pfirrmann grade I),early disc degeneration (Pfirrmann grades II-III), and advanced disc degeneration (Pfirrmann grades IV-V). Regional differences between UTE-T2* and T2* relaxometry and correlation with degeneration were statistically analyzed.Results: UTE-T2* and T2*value correlated negatively with Pfirrmann grades (P < 0.001). In NP, correlations with Pfirrmann grade were high with UTE-T2* values (r =  - 0.733; P < 0.001) and moderate with T2* values (r = -0.654; P < 0.001). Diagnostic accuracy of detecting early IVDD was better with UTE-T2* mapping than T2* mapping (P < 0.05),with receiver operating characteristic analysis area under the curve of 0.715-0.876.Conclusions: UTE-T2* relaxometry provides another promising magnetic resonance imaging sequence for quantitatively evaluate lumbar IVDD and was more accurate than T2*mapping in the earlier stage degenerative process. [ABSTRACT FROM AUTHOR]

Loading intervention is currently the preferred management of tendinopathy, but to what extent different loading regimes influence the mechanical response in tendons is scarcely investigated. Therefore, the purposes of the investigation were to examine the effect of exercise interventions with either high or low load magnitude applied to the tendinopathic patellar tendon and the influence on its mechanical, material, and morphological properties. Forty‐four men with chronic patellar tendinopathy were randomized to 12 weeks of exercising with either; 55% of 1RM throughout the period (MSR group) or 90% of 1RM (HSR group), and with equal total exercise volume in both groups. Mechanical (stiffness), material (T2* relaxation time), and morphological (cross‐sectional area (CSA)) properties were assessed at baseline and after 12 weeks of intervention. MRI with ultra‐short echo times (UTE) and T2*‐mapping was applied to explore if T2* relaxation time could be used as a noninvasive marker for internal material alteration and early change thereof in response to intervention. There was no effect of HSR or MSR on the mechanical (stiffness), material (T2* relaxation time) or morphological (CSA) properties, but both regimes resulted in significant strength gain. In conclusion, there were no statistically superior effect of exercising with high (90%) compared to moderate (55%) load magnitude on the mechanical, material or morphological properties. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: Quantitative magnetic resonance imaging (MRI) ultrashort echo time (UTE) T2* is sensitive to cartilage deep tissue matrix changes after anterior cruciate ligament reconstruction (ACLR). This study was performed to determine whether UTE-T2* profile analysis is a useful clinical metric for assessing cartilage matrix degeneration. This work tests the hypotheses that UTE-T2* depthwise rates of change (profile slopes) correlate with clinical outcome metrics of walking mechanics and patient reported outcomes (PRO) in patients 2 years after ACLR.Design: Thirty-six patients 2 years after ACLR completed knee MRI, gait analysis, and PRO. UTE-T2* maps were generated from MRI images and depthwise UTE-T2* profiles were calculated for weight-bearing cartilage in the medial compartment. UTE-T2* profiles from 14 uninjured subjects provided reference values. UTE-T2* profile characteristics, including several different measures of profile slope, were tested for correlation to kinetic and kinematic measures of gait and also to PRO.Results: Decreasing UTE-T2* profile slopes in ACLR knees moderately correlated with increasing knee adduction moments (r = 0.41, P < 0.015), greater external tibial rotation (r = 0.44, P = 0.007), and moderately negatively correlated with PRO (r = -0.36, P = 0.032). UTE-T2* profiles from both ACLR and contralateral knees of ACLR subjects differed from that of uninjured controls (P < 0.015).Conclusions: The results of this study suggest that decreasing UTE-T2* profile slopes reflect cartilage deep tissue collagen matrix disruption in a population at increased risk for knee osteoarthritis (OA). That UTE-T2* profiles were associated with mechanical and patient reported measures of clinical outcomes support further study into a potential mechanistic relationship between these factors and OA development. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) injury increases risk for posttraumatic knee osteoarthritis (OA). Quantitative ultrashort echo time enhanced T2* (UTE-T2*) mapping shows promise for early detection of potentially reversible subsurface cartilage abnormalities after ACL reconstruction (ACLR) but needs further validation against established clinical metrics of OA risk such as knee adduction moment (KAM) and mechanical alignment. Hypothesis: Elevated UTE-T2* values in medial knee cartilage 2 years after ACLR correlate with varus alignment and higher KAM during walking. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Twenty patients (mean age, 33.1 ± 10.5 years; 11 female) 2 years after ACLR underwent 3.0-T knee magnetic resonance imaging (MRI), radiography, and gait analysis, after which mechanical alignment was measured, KAM during walking was calculated, and UTE-T2* maps were generated. The mechanical axis and the first and second peaks of KAM (KAM1 and KAM2, respectively) were tested using linear regressions for correlations with deep UTE-T2* values in the central and posterior medial femoral condyle (cMFC and pMFC, respectively) and central medial tibial plateau (cMTP). UTE-T2* values from ACL-reconstructed patients were additionally compared with those of 14 uninjured participants (mean age, 30.9 ± 8.9 years; 6 female) using Mann-Whitney U and standard t tests. Results: Central weightbearing medial compartment cartilage of ACL-reconstructed knees was intact on morphological MRI. Mean UTE-T2* values were elevated in both the cMFC and pMFC of ACL-reconstructed knees compared with those of uninjured knees (P = .003 and P = .012, respectively). In ACL-reconstructed knees, UTE-T2* values of cMFC cartilage positively correlated with increasing varus alignment (R = 0.568). Higher UTE-T2* values in cMFC and cMTP cartilage of ACL-reconstructed knees also correlated with greater KAM1 (R = 0.452 and R = 0.463, respectively) and KAM2 (R = 0.465 and R = 0.764, respectively) and with KAM2 in pMFC cartilage (R = 0.602). Conclusion: Elevated deep UTE-T2* values of medial knee cartilage 2 years after ACLR correlate with 2 clinical markers of increased risk of medial knee OA. These results support the clinical utility of MRI UTE-T2* for early diagnosis of subsurface cartilage abnormalities. Longitudinal follow-up of larger cohorts is needed to determine the predictive and staging potential of UTE-T2* for posttraumatic OA. [ABSTRACT FROM AUTHOR]

The article discusses research which focused on the use of quantitative magnetic resonance imaging (MRI) ultrashort echo time (UTE)-enhanced T2 mapping of cartilage and meniscus following anterior cruciate ligament (ACL) reconstruction. Topics explored include the cartilage loss and meniscus dysfunction risks associated with ACL injuries, the recruitment and physical examination of study participants, and the results of the statistical analysis and arthroscopic assessment performed.

The cartilage repair potential of bone marrow-derived stem cells has been well described. Harnessing this potential for human articular cartilage repair remains challenging. Accessing bone marrow repair cells through marrow stimulation techniques such as microfracture is readily achieved with generally good but inconsistent results. Animal and human studies show feasibility for ex vivo processing of bone marrow to isolate, concentrate, and culture mesenchymal stem cells. Nevertheless, it has been difficult to show consistent and clinically meaningful improvement using bone marrow cell preparations above what has been achieved with microfracture. Consequently, microfracture continues to be the simplest and most commonly used method to enhance repair of focal articular cartilage defects. Emerging preclinical work in the equine model suggests a role for enhancing marrow-stimulation techniques through the use of natural scaffolds such as autologous platelet enriched fibrin as well as optimization of joint biology through localized gene therapy to support cartilage repair. In contrast to joint replacement where inert materials of known mechanical properties are used, host biology determines the relative success, failure, and durability of cartilage repair. As such, development of personalized strategies to improve the quality and durability of bone marrow cell-based articular cartilage repair represent exciting new areas of inquiry. Continued advances in stem cell biology, scaffold technologies, and methods to delineate and enhance host biology, both systemically and within the joint, hold promise for harnessing the full power of bone marrow cells to facilitate cartilage repair and regeneration.