Molecular characterization of the circadian clock in paediatric leukaemia patients: a prospective study protocol.

BACKGROUND: In many organisms, including humans, the timing of cellular processes is regulated by the circadian clock. At the molecular level the core-clock consists of transcriptional-translational-feedback loops including several genes such as BMAL1, CLOCK, PERs and CRYs generating circa 24-h rhythms in the expression of about 40% of our genes across all tissues. Previously these core-clock genes have been shown to be differentially expressed in various cancers. Albeit a significant effect in treatment optimization of chemotherapy timing in paediatric acute lymphoblastic leukaemia has previously been reported, the mechanistic role played by the molecular circadian clock in acute paediatric leukaemia remains elusive. METHODS: To characterize the circadian clock, we will recruit patients with newly diagnosed leukaemia and collect time course saliva and blood samples, as well as a single bone marrow sample. From the blood and bone marrow samples nucleated cells will be isolated and further undergo separation into CD19+ and CD19- cells. qPCR is performed on all samples targeting the core-clock genes including BMAL1, CLOCK, PER2 and CRY1. Resulting data will be analysed for circadian rhythmicity using the RAIN algorithm and harmonic regression. DISCUSSION: To the best of our knowledge this is the first study aiming to characterize the circadian clock in a cohort of paediatric patients with acute leukaemia. In the future we hope to contribute to uncovering further vulnerabilities of cancers associated with the molecular circadian clock and in particular adjust chemotherapy accordingly, leading to more targeted toxicity, and hence decreased systemic toxicities.

High Acromial Slope and Low Acromiohumeral Distance Increase the Risk of Retear of the Supraspinatus Tendon After Repair.

BACKGROUND: Retearing of the supraspinatus (SSP) tendon after repair is relatively common, but its cause is rarely clear. Although the role of acromion morphology and glenoid orientation in the pathogenesis of primary SSP tendon tears have frequently been analyzed, their association with the risk of rerupture of a repaired SSP tendon is poorly understood. QUESTIONS/PURPOSES: (1) Is acromial morphology associated with the risk of retear after SSP tendon repair? (2) Is there an association between inclination and version of the glenoid and the odds for retear of the SSP tendon after repair? (3) Are there differences in outcome scores between patients who had intact cuff repairs and those who had retears? METHODS: Between August 2012 and December 2015, we treated 92 patients for SSP tendon tears; all of these patients were considered for inclusion in the present study. We considered patients with complete tear of the SSP that was reconstructed with a double-row repair and a minimum follow-up of 2 years as potentially eligible. Based on these criteria, 28% (26 of 92) were excluded because they had a partial rupture and did not receive a double-row reconstruction. A further 9% (eight of 92) were excluded because of missing planes or slices (such as sagittal, axial, or frontal) on MRI, and another 3% (three of 92) were lost before the minimum study follow-up interval or had incomplete datasets, leaving 60% (55 of 92) for inclusion in the present analysis. All included patients had a minimum follow-up of 2 years; follow-up with MRI occurred at a mean duration of 2.3 ± 0.4 years postoperatively. All patients were asked to complete the Western Ontario Rotator Cuff Index and Oxford Shoulder Scores, and they underwent MRI of the operated-on shoulder. Preoperative true AP radiographs and MR images of the affected shoulders were retrospectively assessed by measuring the acromiohumeral interval, critical shoulder angle, acromial slope, acromial tilt, acromial index, lateral acromial angle, and glenoid version and inclination. The patients also underwent acromioplasty, in which the underface of the acromion was flattened. To rule out any change in the above parameters because of acromioplasty, these parameters were compared using preoperative and postoperative MR images and showed no difference. In addition, the tendon integrity and quality on postoperative MRI were analyzed independently of one another by the same two observers using the Sugaya and Castricini classifications, accounting for atrophy and fatty degeneration of the SSP muscle. To assess interobserver reliability, the two observers took measurements independently from each other. They were orthopaedic residents who completed a training session before taking the measurements. All measurements had excellent intrarater (Cronbach alpha 0.996 [95% confidence interval (CI) 0.99 to 1.00; p > 0.01) and interrater (interrater correlation coefficient 0.975 [95% CI 0.97 to 0.98]; p > 0.01) reliabilities. To answer the study's first question, SSP integrity on postoperative MRI was compared with acromial morphologic parameters measured on preoperative AP radiographs and MR images. To answer the second question, the postoperative integrity and quality of the SSP tendon were correlated with glenoid inclination and glenoid version. To answer our third question, we compared outcome scores between patients with intact SSP tendons and those with reruptured SSP tendons. To investigate any correlation among the acromial morphology, glenoid orientation, and postoperative outcomes, a binomial logarithmic regression analysis was performed. Receiver operating characteristic curves were used to determine cutoff points for the radiologic parameters that showed a correlation in the binomial regression analysis. RESULTS: After controlling for potentially confounding variables such as acromioplasty or preoperative fatty infiltration as well as muscle atrophy, the only morphological parameters associated with a higher risk (adjusted odds ratio) of SSP tendon rerupture were the acromiohumeral interval (adjusted OR 0.9 [95% CI 0.9 to 0.99]; p < 0.01) and acromial slope (adjusted OR 1.4 [95% CI 1.1 to 1.8]; p < 0.01). The critical shoulder angle, acromial tilt, acromial index, and lateral acromial angle were not associated with the risk of rerupture. The cutoff values for acromial slope and acromiohumeral interval were 24.5° and 7.4 mm, respectively. Patients with an acromiohumeral interval smaller than 7.4 mm or an acromial slope greater than 24.5° had higher odds (acromiohumeral interval: OR 11 [95% CI 2 to 46]; p = 0.01 and acromial slope: OR 9 [95% CI 2 to 46]; p = 0.04) for rerupture of the SSP. No difference was found between patients with intact SSP tendons and those with reruptured SSP tendons in terms of glenoid inclination (6° ± 4° versus 6° ± 3°, mean difference 0.8° [-1° to 3°]; p < 0.48) and glenoid version (-2° ± 3° versus -3° ± 3°, mean difference 1° [-1° to 3°]; p < 0.30). No difference was found between the intact and reruptured SSP groups regarding clinical outcomes (Western Ontario Rotator Cuff Index: 98 ± 2 versus 97 ± 3, mean difference 0.73 [95% CI -0.30 to 0.31]; p = 0.96; Oxford Shoulder Score: 26 ± 13 versus 23 ± 10, mean difference 2.80 [95% CI -4.12 to 9.72]; p = 0.41). CONCLUSION: The preoperative acromiohumeral interval and acromial slope are associated with SSP tendon rerupture after repair. Conversely, the critical shoulder angle, acromial tilt, lateral acromial angle, and acromial index had no association with the postoperative outcome. Additionally, glenoid inclination and version were not associated with the rerupture rate after SSP tendon repair. A detailed analysis of the acromiohumeral interval and acromial slope is recommended in clinical practice in patients undergoing SSP tendon repair. Surgeons should consider measuring the acromiohumeral interval and acromial slope preoperatively when performing SSP repair, especially in the context of planned acromioplasties. Future studies should investigate the role of acromioplasty during SSP repair in patients with a pathologic acromial slope and acromiohumeral interval. In this context, it should be determined whether a more-radical acromioplasty could reduce the risk of rerupture of the SSP in these patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

MRI Allows Accurate Measurement of Glenoid Bone Loss.

BACKGROUND: Bony Bankart lesions larger than a certain size can lead to a high redislocation rate, despite treatment with Bankart repair. Detection and measurement of glenoid bone loss play key roles in selecting the appropriate surgical therapy in patients with shoulder instability. There is controversy about which diagnostic modalities, using different measurement methods, provide the best diagnostic validity. QUESTIONS/PURPOSES: (1) What are the diagnostic accuracies of true AP radiographs, West Point (WP) view radiographs, MRI, and CT to detect glenoid bone loss? (2) Are there differences in the measurements of glenoid bone loss on MRI and CT? (3) What are the intrarater and interrater reliabilities of CT and MRI to measure glenoid bone loss? METHODS: Between August 2012 and February 2017, we treated 80 patients for anterior shoulder instability. Of those, we considered patients with available preoperative true AP radiographs, WP radiographs, CT images, and MR images of the affected shoulder as potentially eligible. Based on that, 63% (50 of 80) of patients were eligible for analysis; 31% (25 of 80) were excluded because not all planes or slices (such as sagittal, axial, or frontal) of each diagnostic imaging modalities were available and 7% (5 of 80) because of the insufficient quality of diagnostic images (for example, setting of the layers did not allow adequate en face view of the glenoid). Preoperative true AP radiographs, WP radiographs, CT images and MR images of the affected shoulders were retrospectively assessed for the presence of glenoid bone loss by two blinded observers at a median (range) 25 months (12 to 66) postoperatively. To evaluate sensitivity, specificity, positive predictive value, negative predictive value, accuracy, diagnostic odds ratio, positive likelihood ratio, negative likelihood ratio, and area under the curve (AUC), we compared the detection of glenoid bone loss at follow-up achieved with the aforementioned imaging modalities with intraoperative arthroscopic detection. In all patients with glenoid bone loss, two blinded observers measured the size of the glenoid bone loss on preoperative CT and MR images using six measuring techniques: depth and length of the glenoid bone loss, Bigliani classification, best-fit circle width loss method, AP distance method, surface area method, and Gerber X ratio. Subsequently, the sizes of the glenoid bone loss determined using CT and MRI were compared. To estimate intraobserver and interobserver reliability, measurements were performed in a blinded fashion by two observers. Their level of experience was equivalent to that of orthopaedic residents, and they completed a training protocol before the measurements. RESULTS: For the ability to accurately diagnose Bankart lesions, the AUC (accuracy of a diagnostic test; the closer to 1.0, the more accurate the test) was good for MRI (0.83 [95% confidence interval 0.70 to 0.94]; p < 0.01), fair for CT (0.79 [95% CI 0.66 to 0.92]; p < 0.01), poor for WP radiographs (0.69 [95% CI 0.54 to 0.85]; p = 0.02) and failed for true AP radiographs (0.55 [95% CI 0.39 to 0.72]; p = 0.69). In paired comparisons, there were no differences between CT and MRI regarding (median [range]) lesion width (2.33 mm [0.35 to 4.53] versus 2.26 mm [0.90 to 3.47], p = 0.71) and depth (0.42 mm [0.80 to 1.39] versus 0.40 mm [0.06 to 1.17]; p = 0.54), and there were no differences concerning the other measurement methods: best-fit circle width loss method (15.02% [2.48% to 41.59%] versus 13.38% [2.00% to 36.34%]; p = 0.66), AP distances method (15.48% [1.44% to 42.01%] versus 12.88% [1.43% to 36.34%]; p = 0.63), surface area method (14.01% [0.87% to 38.25] versus 11.72% [2.45% to 37.97%]; p = 0.68), and Gerber X ratio (0.75 [0.13 to 1.47] versus 0.76 [0.27 to 1.13]; p = 0.41). Except for the moderate interrater reliability of the Bigliani classification using CT (intraclass correlation coefficient = 0.599 [95% CI 0.246 to 0.834]; p = 0.03) and acceptable interrater reliability of the Gerber X ratio using CT (0.775 [95% CI 0.542 to 0.899]; p < 0.01), all other measurement methods had good or excellent intrarater and interrater reliabilities on MRI and CT. CONCLUSION: The results of this study show that CT and MRI can accurately detect glenoid bone loss, whereas WP radiographs can only recognize them poorly, and true AP radiographs do not provide any adequate diagnostic accuracy. In addition, when measuring glenoid bone loss, MRI images of the analyzed measurement methods yielded sizes that were no different from CT measurements. Finally, the use of MRI images to measure Bankart bone lesions gave good-to-excellent reliability in the present study, which was not inferior to CT findings. Considering the advantages including lower radiation exposure and the ability to assess the condition of the labrum using MRI, we believe MRI can help surgeons avoid ordering additional CT imaging in clinical practice for the diagnosis of anterior shoulder instability in patients with glenoid bone loss. Future studies should investigate the reproducibility of our results with a larger number of patients, using other measurement methods that include examination of the opposite side or with three-dimensional reconstructions. LEVEL OF EVIDENCE: Level I diagnostic study.

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers.

BACKGROUND: Knotted and knotless single-anchor reconstruction techniques are frequently performed to reconstruct full-thickness tears of the upper portion of subscapularis tendon. However, it is unclear whether one technique is superior to the other. QUESTIONS/PURPOSES: (1) When comparing knotless and knotted single-anchor reconstruction techniques in full-thickness tears of the upper subscapularis tendon, is there a difference in stiffness under cyclic load? (2) Are there differences in cyclic gapping between knotless and knotted reconstructions? (3) Are there differences in the maximal stiffness, yield load, and ultimate load to failure? (4) What are the modes of failure of knotless and knotted reconstruction techniques? METHODS: Eight matched pairs of human cadaveric shoulders were dissected, and a full-thickness tear of the subscapularis tendon (Grade 3 according to the Fox and Romeo classification) was created. The cadavers all were male specimens, with a median (range) age of 69 years (61 to 75). Before biomechanical evaluation, the specimens were randomized into two equal reconstruction groups: knotless single anchor and knotted single anchor. All surgical procedures were performed by a single orthopaedic surgeon who subspecializes in sports orthopedics and shoulder surgery. With a customized set up that was integrated in a dynamic material testing machine, the humeri were consecutively loaded from 10 N to 60 N, from 10 N to 100 N, and from 10 N to 180 N for 50 cycles. Furthermore, the gapping behavior of the tear was analyzed using a video tracking system. Finally, the stiffness, gapping, maximal stiffness, yield loads, and maximum failure loads of both reconstruction groups were statistically analyzed. Failure was defined as retearing of the reconstructed gap threshold due to rupture of the tendon and/or failure of the knots or anchors. After biomechanical testing, bone quality was measured at the footprint of the subscapularis using microCT in all specimens. Bone quality was equal between both groups. To detect a minimum 0.15-mm difference in gap formation between the two repair techniques (with a 5% level of significance; α = 0.05), eight matched pairs (n = 16 in total) were calculated as necessary to achieve a power of at least 90%. RESULTS: The first study question can be answered as follows: for stiffness under cyclic load, there were no differences with the numbers available between the knotted and knotless groups at load stages of 10 N to 60 N (32.7 ± 3.5 N/mm versus 34.2 ± 5.6 N/mm, mean difference 1.5 N/mm [95% CI -6.43 to 3.33]; p = 0.55), 10 N to 100 N (45.0 ± 4.8 N/mm versus 45.2 ± 6.0 N/mm, mean difference 0.2 N/mm [95% CI -5.74 to 6.04]; p = 0.95), and 10 N to 180 N (58.2 ± 10.6 N/mm versus 55.2 ± 4.7 N/mm, mean difference 3 N/mm [95% CI -5.84 to 11.79]; p = 0.48). In relation to the second research question, the following results emerged: For cyclic gapping, there were no differences between the knotted and knotless groups at any load levels. The present study was able to show the following with regard to the third research question: Between knotted and knotless repairs, there were no differences in maximal load stiffness (45.3 ± 8.6 N/mm versus 43.5 ± 10.2 N/mm, mean difference 1.8 [95% CI -11.78 to 8.23]; p = 0.71), yield load (425.1 ± 251.4 N versus 379.0 ± 169.4 N, mean difference 46.1 [95% CI -276.02 to 183.72]; p = 0.67), and failure load (521.1 ± 266.2 N versus 475.8 ± 183.3 N, mean difference 45.3 [95% CI -290.42 to 199.79]; p = 0.69). Regarding the fourth question concerning the failure modes, in the knotted repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 6 of 8, and no suture slipped from the eyelet; in the knotless repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 3 of 8, and the threads slipped from the eyelet in 3 of 8. CONCLUSION: With the numbers available, we found no differences between single-anchor knotless and knotted reconstruction techniques used to repair full-thickness tears of the upper portion of subscapularis tendon. CLINICAL RELEVANCE: The reconstruction techniques we analyzed showed no differences in terms of their primary stability and biomechanical properties at the time of initial repair and with the numbers available. In view of these experimental results, it would be useful to conduct a clinical study in the future to verify the translationality of the experimental data of the present study.

Off-track Hill-Sachs lesions predispose to recurrence after nonoperative management of first-time anterior shoulder dislocations.

PURPOSE: The purpose of this study was to evaluate whether the presence of an off-track Hill-Sachs lesion has an impact on the recurrence rate after nonoperative management of first-time anterior shoulder dislocations. METHODS: A retrospective cohort study was planned with a follow-up via questionnaire after a minimum of 24 months. Fifty four patients were included in the study (mean age: 29.5 years; 16 female, 38 male). All of these patients opted for primary nonoperative management after first-time traumatic anterior shoulder dislocation, in some cases even against the clinician's advice. The glenoid track and the Hill-Sachs interval were evaluated in the MRI scans. The clinical outcome was evaluated via a shoulder-specific questionnaire, ASES-Score and Constant Score. Further, patients were asked to report on recurrent dislocation (yes/no), time to recurrent dislocation, pain, feeling of instability and satisfaction with nonoperative management. RESULTS: In 7 (13%) patients, an off-track Hill-Sachs lesion was present, while in 36 (67%) the lesion was on-track and 11 (20%) did not have a structural Hill-Sachs lesion at all. In total, 31 (57%) patients suffered recurrent dislocations. In the off-track group, all shoulders dislocated again (100%), while 21 (58%) in the on-track group and 3 (27%) in the no structural Hill--Sachs lesion group had a recurrent dislocation, p = 0.008. The mean age in the group with a recurrence was 23.7 ± 10.1 years, while those patients without recurrent dislocation were 37.4 ± 13.1 years old, p < 0.01. The risk for recurrence in patients under 30 years of age was higher than in those older than 30 years (OR = 12.66, p < 0.001). There were no significant differences between patients with on- and off-track lesions regarding patients' sex, height, weight and time to reduction and glenoid diameter. Off-track patients were younger than on-track patients (24.9 ± 7.3 years vs. 29.6 ± 13.6 years). However, this difference was not statistically significant. CONCLUSION: The presence of an off-track Hill-Sachs lesion leads to significantly higher recurrence rates compared to on-track or no structural Hill--Sachs lesions in patients with nonoperative management and should be considered when choosing the right treatment option. Therefore, surgical intervention should be considered in patients with off-track Hill-Sachs lesions. LEVEL OF EVIDENCE: IV.

Comparison of Knotless and Knotted Single-Anchor Repair for Ruptures of the Upper Subscapularis Tendon: Outcomes at 2-Year Follow-up.

Background: Both knotted and knotless single-anchor repair techniques are used to repair transmural ruptures of the upper subscapularis (SSC) tendon. However, it is still unclear which technique provides better clinical and radiological results. Purpose/Hypothesis: To compare the clinical and magnetic resonance imaging (MRI) outcomes of knotless and knotted single-anchor repair techniques in patients with a transmural rupture of the upper SSC tendon at 2-year follow-up. It was hypothesized that the 2 techniques would not differ significantly in outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Forty patients with a transmural tear of the upper SSC tendon (grade 2 or 3 according to Fox and Romeo) were retrospectively enrolled. Depending on the repair technique, patients were assigned to either the knotless single-anchor or knotted single-anchor group. After a mean follow-up of 2.33 ± 0.43 years, patients were assessed by the ASES, WORC, OSS, CS, and SSV. A clinical examination that included the bear-hug, the lift-off, and the belly-press tests was performed, in which the force exerted by the subjects was measured. In addition, all patients underwent MRI of the affected shoulder to assess repair integrity, tendon width, fatty infiltration, signal-to-signal ratio of the upper and lower SSC muscle, and atrophy of the SSC muscle. Results: No significant difference was found between the 2 groups on any of the clinical scores [ASES (P = .272), WORC (P = .523), OSS (P = .401), CS (P = .328), SSV (P = .540)] or on the range-of-motion or force measurements. Apart from a higher signal-to-signal ratio of the lower SSC muscle in the knotless group (P = .017), no significant difference on imaging outcomes was found between the 2 groups. Conclusion: Both techniques can be used in surgical practice, as neither was found to be superior to the other in terms of clinical or imaging outcomes at 2-year follow-up.

Case Report: Rubella Virus-Induced Cutaneous Granulomas in Two Pediatric Patients With DNA Double Strand Breakage Repair Disorders - Outcome After Hematopoietic Stem Cell Transplantation.

We report two patients with DNA repair disorders (Artemis deficiency, Ataxia telangiectasia) with destructive skin granulomas, presumably triggered by live-attenuated rubella vaccinations. Both patients showed reduced naïve T cells. Rapid resolution of skin lesions was observed following hematopoietic stem cell transplantation. However, the patient with AT died due to complications of severe hepatic veno-occlusive disease 6 month after HSCT. Dried blood spots obtained after birth were available from this patient and showed absent T-cell receptor excision circles (TRECs). Therefore, newborn screening may help to prevent patients with moderate T-cell deficiency from receiving live-attenuated rubella vaccine potentially causing granulomas.

Novelty seeking is associated with increased body weight and orbitofrontal grey matter volume reduction.

Novelty seeking (NS) has previously been identified as a personality trait that is associated with elevated body mass index (BMI) and obesity. Of note, both obesity and reduced impulse control - a core feature of NS - have previously been associated with grey matter volume (GMV) reductions in the orbitofrontal cortex (OFC). Yet, it remains unknown, if body weight-related grey matter decline in the OFC might be explained by higher levels of NS. To address this question, we studied associations between NS, BMI and brain structure in 355 healthy subjects. Brain images were pre-processed using voxel-based morphometry (VBM). BMI was calculated from self-reported height and weight. The Tridimensional Personality Questionnaire (TPQ) was used to assess NS. NS and BMI were associated positively (r = .137, p = .01) with NS being a significant predictor of BMI (B = 0.172; SE B = 0.05; ß = 0.184; p = 0.001). Significant associations between BMI and GMV specifically in the OFC (x = -44, y = 56, z = -2, t(350) = 4.34, k = 5, pFWE = 0.011) did not uphold when correcting for NS in the model. In turn, a significant negative association between NS and OFC GMV was found independent of BMI (x = -2, y = 48, z = -10, t(349) = 4.42, k = 88, pFWE = 0.008). Body mass-related grey matter decrease outside the OFC could not be attributed to NS. Our results suggest that body-weight-related orbitofrontal grey matter reduction can at least partly be linked to higher levels of NS. Given the pivotal role of the OFC in overweight as well as cognitive domains such as impulse inhibition, executive control and reward processing, its association with NS seems to provide a tenable neurobiological correlate for future research.