Integrity of the Untorn Articular-Sided Tendon in Bursal-Sided Partial-Thickness Rotator Cuff Tear: A Comparative Study of Apoptotic Activity in Torn and Untorn Layers

Background: Conversion to full-thickness tear in partial-thickness rotator cuff tears (PTRCTs) is based on the quality and thickness of the normal-looking untorn rotator cuff layer. However, whether the untorn tendon is a healthy tissue remains to be elucidated. Purpose: To compare the apoptotic gene expression of the untorn articular layer with the torn bursal layer in PTRCTs. Study Design: Controlled laboratory study. Methods: Tendon tissues were harvested from 20 patients undergoing arthroscopic surgery for partial-thickness rotator cuff repair. As a control group, the tissues were harvested during intramedullary nail fixation in 10 proximal humeral fractures. In the experimental group, the samples were harvested from 2 sites: the torn bursal-sided tendon and the untorn articular-sided tendon. Hematoxylin and eosin (H&E) staining was conducted for basic histological evaluation, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to detect apoptosis of tissue cells. The expression of caspase 3, 8, and 9 was confirmed immunohistochemically. Western blot analysis was used to assay the caspase activities. Results: In H&E staining, the direction of collagen bundles in untorn tendon was disoriented when compared with those of control tendon. However, the shape of the nuclei was not different, although the nuclei of the untorn tendon showed apoptosis in the TUNEL staining similar to those of the torn tendon. The immunohistochemical staining of caspase 3, 8, and 9 was increased concomitantly in untorn and torn tendons. All of the caspase activities in the untorn articular layer and torn bursal layer were significantly higher than in controls ( P < .05). However, no significant differences were found between the two layers ( P > .05). Conclusion: The study demonstrates that apoptotic gene expression is increased not only in the torn bursal layer but also in the untorn articular layer of PTRCTs. Clinical Relevance: The untorn articular layer of PTRCTs is abnormal, which triggers postoperative pain and further rotator cuff tears. Therefore, treatment of the abnormal untorn articular layer is essential in bursal-sided PTRCTs.

Download Full-text

The Effect of Intravitreal Azithromycin on the Albino Newborn Rabbit Retina

The Open Ophthalmology Journal ◽

10.2174/1874364101610010012 ◽

2016 ◽

Vol 10 (1) ◽

pp. 12-16

Author(s):

Duygu Cam ◽

Ali Osman Saatci ◽

Serap Cilaker Micili ◽

Bekir Ugur Ergur ◽

Revan Yildirim Karabag ◽

...

Keyword(s):

Light Microscopy ◽

Caspase 3 ◽

Rabbit Model ◽

Study Groups ◽

Terminal Deoxynucleotidyl Transferase ◽

Control Group ◽

Tunel Staining ◽

Rabbit Retina ◽

Newborn Rabbit ◽

The Right

Purpose: To evaluate the effect of intravitreal azithromycin on the retina in a newborn rabbit model. Methods: Twelve, two-week old New Zealand albino rabbits were divided into two groups (six in each). The right eyes of six rabbits received 0.75 mg (0.05 mL) azithromycin and the right eyes of the remaining six rabbits 1.5 mg (0.1 mL) azithromycin intravitreally. Left eyes were served as the control and received the same volume of saline. All eyes were enucleated at the third postinjection week. Retinal histology was examined by light microscopy. Apoptosis of the retinal cells was further evaluated by immunohistochemical staining for caspase-3 and in situ terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling (TUNEL) of DNA fragments. Results: Light microscopy demonstrated no retinal abnormalities in all eyes. However, retinal nuclear DNA fragmentation was evident in both study groups (33.6% with 1.5 mg and 21.4% with 0.75 mg azithromycin) with the TUNEL method. TUNEL staining ratio was statistically higher only in the second group treated with 1.5 mg azithromycin when compared to the control group (p=0.01 Mann Whitney U test). The ratio of caspase-3 positive cells in the two study groups was 21.5% and 20.2%, respectively. Caspase-3 staining ratio was statistically higher in both study groups when compared to the control eyes (p=0.00, p=0.00 respectively). The difference of TUNEL staining ratio between the two study groups was statistically significant (p=0.028), but there were no statistically significant differences in the two study groups by caspase-3 staining (p=0.247). Conclusion: In newborn rabbits, intravitreal azithromycin injection resulted in an apoptotic activity in the photoreceptor, bipolar and ganglion cells. Immunohistochemical analysis suggested that doses of 0.75 mg and 1.5 mg azithromycin, administered intravitreally might be toxic to the newborn rabbit retina.

Download Full-text

Biceps Augmentation Outperforms Tear Completion Repair or In Situ Repair for Bursal-Sided Partial-Thickness Rotator Cuff Tears in a Rabbit Model

The American Journal of Sports Medicine ◽

10.1177/03635465211053334 ◽

2021 ◽

pp. 036354652110533

Author(s):

Junjie Xu ◽

Yufeng Li ◽

Zipeng Ye ◽

Chenliang Wu ◽

Kang Han ◽

...

Keyword(s):

Rotator Cuff ◽

Failure Load ◽

Biceps Tendon ◽

Rotator Cuff Tears ◽

Histological Evaluation ◽

Bicipital Groove ◽

Partial Thickness ◽

Over Time ◽

In Situ Repair

Background: There is an ongoing debate on the treatment of bursal-sided partial-thickness rotator cuff tears (PTRCTs), including ideal repair techniques. Augmentation using a collagen patch has been introduced as a new surgical approach to treat PTRCTs, while the effect of autogenous biceps augmentation (BA) has not been investigated. Purpose: To analyze the effects of BA on bursal-sided PTRCTs and compare its histological and biomechanical results with those of tear completion followed by repair and in situ repair (ISR). Study Design: Controlled laboratory study. Methods: Unilateral chronic PTRCTs were created in 96 mature New Zealand White rabbits, which were randomly divided into 4 groups: no repair, tear completion repair (TCR), ISR, and BA. A new bicipital groove was fabricated in BA for the biceps tendon that was transferred to augment the bursal-sided PTRCT repair. In each group, we sacrificed 6 rabbits for biomechanical testing of the whole tendon-to-bone complex (WTBC) and 6 for histological evaluation of bursal- and articular-sided layers at 6 and 12 weeks postoperatively. Healing responses between the biceps and new bicipital groove in the BA group were determined using histological analysis, and final groove morphologies were evaluated using micro–computed tomography. Results: The remaining tendon and enthesis in bursal-sided PTRCTs progressively degenerated over time. WTBCs of ISR exhibited a larger failure load than those of TCR, although better healing properties in the bursal-sided repaired site were achieved using TCR based on histological scores and superior articular-sided histological scores were observed using ISR. However, WTBCs of BA displayed the best biomechanical results and superior histological scores for bursal- and articular-sided regions. The new bicipital groove in BA remodeled over time and formed similar morphologies to a native groove, which provided a mature bone bed for transferred biceps tendon healing to augment bursal-sided PTRCTs. Conclusion: BA achieved better biomechanical and histological results for repairing bursal-sided PTRCTs as compared with TCR and ISR. When compared with that of TCR, the WTBC of ISR exhibited a higher failure load, showing histological superiority in the articular-sided repair and inferiority in the bursal-sided repair. Clinical Relevance: BA may be an approach to improve bursal-sided PTRCT repair in humans, which warrants further clinical investigation.

Download Full-text

The association between acromial anatomy and articular-sided partial thickness of rotator cuff tears

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04639-1 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Cen Tao Liu ◽

Jia Qing Miao ◽

Hua Wang ◽

Heng an Ge ◽

Xian Hui Wang ◽

...

Keyword(s):

Rotator Cuff ◽

Pearson Correlation ◽

Rotator Cuff Tears ◽

Control Group ◽

Partial Thickness ◽

History Of ◽

Mri Diagnosis ◽

Magnetic Resonance Imaging Mri ◽

Acromiohumeral Distance ◽

The Relationship

Abstract Background Acromial anatomy has been found to be correlated with degenerative full-thickness rotator cuff tears in current studies. However, research on the relationship between acromial anatomy and articular-sided partial thickness of rotator cuff tears (PTRCTs) is still lacking. The purpose of this study was to evaluate whether these imaging graphic parameters exhibit any association between acromial anatomy and degenerative articular-sided PTRCTs. Methods Between January 2016 and December 2018, a total of 91 patients without a history of trauma underwent arthroscopy as an articular-sided PTRCT group. In the control group, with age- and sex-matched patients, we selected 91 consecutive outpatient patients who underwent shoulder magnetic resonance imaging (MRI) because of shoulder pain and an MRI diagnosis of only synovial hyperplasia and effusion. MRI was used to measure the acromial type, acromiohumeral distance (AHD), lateral acromial angle (LAA), acromion index (AI), and critical shoulder angle (CSA) by 2 independent observers. Results The acromion type, AHD and LAA showed no difference between degenerative articular-sided PTRCTs and controls (P = 0.532, 0.277, and 0.108, respectively). AI and CSA were significantly higher in degenerative articular-sided PTRCTs (P = 0.002 and 0.003, respectively). A good correlation was found between AI and CSA to measurement(Pearson correlation coefficient = 0.631). Conclusions Our study revealed that higher AI and CSA were found in degenerative articular-sided PTRCTs. Acromial anatomy with a large acromial extension was associated with the occurrence of degenerative articular-sided PTRCTs.

Download Full-text

Tear Completion Versus In Situ Repair for 50% Partial-Thickness Bursal-Side Rotator Cuff Tears: A Biomechanical and Histological Study in an Animal Model

The American Journal of Sports Medicine ◽

10.1177/0363546520909854 ◽

2020 ◽

Vol 48 (8) ◽

pp. 1818-1825

Author(s):

Anil Pulatkan ◽

Wasim Anwar ◽

Omer Ayık ◽

Ergun Bozdag ◽

Ayse Nur Yildirim ◽

...

Keyword(s):

Rotator Cuff ◽

Bone Healing ◽

Histological Study ◽

Rabbit Model ◽

Rotator Cuff Tears ◽

Control Group ◽

Mean Values ◽

Partial Thickness ◽

In Situ Repair

Background: Tear completion followed by repair (TCR) and in situ repair (ISR) have been widely used for bursal-side partial-thickness rotator cuff tears (PTRCTs). Both techniques have shown favorable results; however, controversy continues in terms of the best management. Purpose: To compare the histological and biomechanical outcomes of these 2 techniques for 50% partial-thickness bursal-side rotator cuff tear repair in a rabbit model. Study Design: Controlled laboratory study. Methods: A total of 27 rabbits were used in this experimental study. Seven rabbits were sacrificed at the beginning of the study to form an intact tendon control group. A chronic 50% partial-thickness bursal-side tear model was created in 20 rabbits, and 5 rabbits were sacrificed for biomechanical testing of chronic partial-thickness tears (control group) without repair. In 15 rabbits, partial-thickness tears were repaired after 8 weeks. Partial-thickness tears in the right shoulders were completed to full thickness and repaired; in contrast, left shoulders were repaired in situ. All rabbits were euthanized 8 weeks after the repair. The tendons were tested biomechanically for ultimate failure, linear stiffness, and displacement. Histological evaluations of tendon-to-bone healing were performed via the modified Watkins score. Results: Macroscopically, all repaired tendons were attached to the greater tuberosity. The TCR group had a higher failure load than the ISR group, with mean values of 140.4 ± 13.8 N and 108.1 ± 16.6 N, respectively ( P = .001). The modified Watkins score was significantly higher in the TCR group (23.5; range, 22-27) than in the ISR group (19.5; range, 16-22) ( P = .009). Conclusion: Both repair techniques are effective for 50% partial-thickness bursal-side rotator cuff tears; however, TCR yields significantly superior biomechanical and histological characteristics compared with ISR. Clinical Relevance: Tear completion and repair technique may increase tendon-to-bone healing and thereby reduce re-rupture rate in the partial thickness bursal side rotator cuff tears.

Download Full-text

Substantial Biomechanical Improvement by Extracorporeal Shockwave Therapy After Surgical Repair of Rodent Chronic Rotator Cuff Tears

The American Journal of Sports Medicine ◽

10.1177/0363546519854760 ◽

2019 ◽

Vol 47 (9) ◽

pp. 2158-2166 ◽

Cited By ~ 4

Author(s):

Xaver Feichtinger ◽

Xavier Monforte ◽

Claudia Keibl ◽

David Hercher ◽

Jakob Schanda ◽

...

Keyword(s):

Gene Expression ◽

Rotator Cuff ◽

Clinical Relevance ◽

Rotator Cuff Tears ◽

Control Group ◽

Functional Evaluation ◽

Extracorporeal Shockwave Therapy ◽

Extracorporeal Shockwave ◽

Shockwave Therapy ◽

Intensity Measurements

Background: Characteristics of chronic rotator cuff tears include continuous loss of tendon structure as well as tendon elasticity, followed by a high failure rate after surgical reconstruction. Several studies have already shown the beneficial effect of extracorporeal shockwave therapy (ESWT) on tissue regeneration in tendon pathologies. Hypothesis: ESWT improves biomechanical tendon properties as well as functional shoulder outcomes in chronic rotator cuff reconstruction in rodents. Study Design: Controlled laboratory study. Methods: After tendon detachment and 3 weeks of degeneration, a subsequent transosseous reattachment of the supraspinatus tendon was performed in 48 adult male Sprague-Dawley rats (n = 16 per group). Rodents were randomly assigned to 3 study groups: no ESWT/control group, intraoperative ESWT (IntraESWT), and intra- and postoperative ESWT (IntraPostESWT). Shoulder joint function, as determined by gait analysis, was assessed repeatedly during the observation period. Eight weeks after tendon reconstruction, the rats were euthanized, and biomechanical and gene expression analyses were performed. Results: Macroscopically, all repairs were intact at the time of euthanasia, with no ruptures detectable. Biomechanical analyses showed significantly improved load-to-failure testing results in both ESWT groups in comparison with the control group (control, 0.629; IntraESWT, 1.102; IntraPostESWT, 0.924; IntraESWT vs control, P≤ .001; IntraPostESWT vs control, P≤ .05). Furthermore, functional gait analyses showed a significant enhancement in intensity measurements for the IntraPostESWT group in comparison with the control group ( P≤ .05). Gene expression analysis revealed no significant differences among the 3 groups. Conclusion: Clearly improved biomechanical results were shown in the single-application and repetitive ESWT groups. Furthermore, functional evaluation showed significantly improved intensity measurements for the repetitive ESWT group. Clinical Relevance: This study underpins a new additional treatment possibility to prevent healing failure. Improved biomechanical stability and functionality may enable faster remobilization as well as an accelerated return to work and sports activities. Furthermore, as shockwave therapy is a noninvasive, easy-to-perform, cost-effective treatment tool with no undesired side effects, this study is of high clinical relevance in orthopaedic surgery. Based on these study results, a clinical study has already been initiated to clinically confirm the improved functionality by ESWT.

Download Full-text

Can ultrasound suffice for triaging patients requiring surgical correction of rotator cuff tears—a comparative evaluation of ultrasound and magnetic resonance imaging

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-021-00477-2 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Aniket Agarwal ◽

Kavita Vani ◽

Anurag Batta ◽

Kavita Verma ◽

Shishir Chumber

Keyword(s):

Rotator Cuff ◽

Biceps Tendon ◽

Surgical Correction ◽

Statistical Testing ◽

Rotator Cuff Tears ◽

Full Thickness ◽

Partial Thickness ◽

Linear Probe ◽

Significant Difference ◽

Sensitivity Specificity

Abstract Background Objectives: To comparatively evaluate the role of ultrasound and MRI in rotator cuff and biceps tendon pathologies and to establish ultrasound as a consistently reproducible, quick and accurate primary investigation modality sufficient to triage patients requiring surgical correction of full thickness rotator cuff tears. Methods: Fifty patients, clinically suspected to have rotator cuff and/or biceps tendon pathologies, with no contraindications to MRI, were evaluated by US and MRI, in a prospective cross-sectional observational study. US was done with high-frequency linear probe, and MRI was done on a 1.5-T scanner using T1 oblique sagittal, proton density (PD)/T2 fat-suppressed (FS) oblique sagittal, T1 axial, PD/T2 FS axial, T1 oblique coronal, T2 oblique coronal and PD FS oblique coronal sequences. Statistical testing was conducted with the statistical package for the social science system version SPSS 17.0. The sensitivity, specificity, PPV, NPV and accuracy were also calculated to analyze the diagnostic accuracy of US findings correlating with MRI findings. A p value less than 0.05 was taken to indicate a significant difference. Results Mean age was 45 years; 74% patients were males; 77% females and 60% males had tears. Majority of patients with rotator cuff tears were in the sixth decade of life. The frequency of tears was higher among older patients. Fourteen percent of patients had full thickness tears while 64% had partial thickness tears. US was comparable to MRI for detection of full thickness tears with overall sensitivity, specificity, PPV and accuracy of 93.8%, 100%, 100% and 98.2%, respectively (p value < 0.001). For partial thickness tears, US had overall sensitivity, specificity, PPV and accuracy of 75.6%, 82.6%, 89.5% and 78%, respectively (p value < 0.001), as compared to MRI. Subacromial-subdeltoid bursal effusion and long head of biceps tendon sheath effusion were common associated, though, non-specific findings. Conclusion Ultrasound findings in our study were found to be in significant correlation with findings on MRI in detection of rotator cuff tears. US was equivalent to MRI in detection of full thickness tears and fairly accurate for partial thickness tears. Therefore, US should be considered as the first line of investigation for rotator cuff pathologies.

Download Full-text

Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3-independent pathway

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00098.2004 ◽

2004 ◽

Vol 287 (4) ◽

pp. H1730-H1739 ◽

Cited By ~ 37

Author(s):

Ron Zohar ◽

Baoqian Zhu ◽

Peter Liu ◽

Jaro Sodek ◽

C. A. McCulloch

Keyword(s):

Cell Death ◽

Caspase 3 ◽

Cardiac Fibroblasts ◽

Chromatin Condensation ◽

Terminal Deoxynucleotidyl Transferase ◽

Tunel Staining ◽

Wild Type ◽

Nuclear Fragmentation ◽

A Cell

Reperfusion-induced oxidative injury to the myocardium promotes activation and proliferation of cardiac fibroblasts and repair by scar formation. Osteopontin (OPN) is a proinflammatory cytokine that is upregulated after reperfusion. To determine whether OPN enhances fibroblast survival after exposure to oxidants, cardiac fibroblasts from wild-type (WT) or OPN-null (OPN−/−) mice were treated in vitro with H2O2to model reperfusion injury. Within 1 h, membrane permeability to propidium iodide (PI) was increased from 5 to 60% in OPN−/−cells but was increased to only 20% in WT cells. In contrast, after 1–8 h of treatment with H2O2, the percent of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-stained cells was more than twofold higher in WT than OPN−/−cells. Electron microscopy of WT cells treated with H2O2showed chromatin condensation, nuclear fragmentation, and cytoplasmic and nuclear shrinkage, which are consistent with apoptosis. In contrast, H2O2-treated OPN−/−cardiac fibroblasts exhibited cell and nuclear swelling and membrane disruption that are indicative of cell necrosis. Treatment of OPN−/−and WT cells with a cell-permeable caspase-3 inhibitor reduced the percentage of TUNEL staining by more than fourfold in WT cells but decreased staining in OPN−/−cells by ∼30%. Although the percentage of PI-permeable WT cells was reduced threefold, the percent of PI-permeable OPN−/−cells was not altered. Restoration of OPN expression in OPN−/−fibroblasts reduced the percentage of PI-permeable cells but not TUNEL staining after H2O2treatment. Thus H2O2-induced cell death in OPN-deficient cardiac fibroblasts is mediated by a caspase-3-independent, necrotic pathway. We suggest that the increased expression of OPN in the myocardium after reperfusion may promote fibrosis by protecting cardiac fibroblasts from cell death.

Download Full-text