Histopathology of rotator cuff tears

Mitochondrial mechanisms in the pathogenesis of chronic inflammatory musculoskeletal disorders

Chronic inflammatory musculoskeletal disorders characterized by prolonged muscle inflammation, resulting in enduring pain and diminished functionality, pose significant challenges for the patients. Emerging scientific evidence points to mitochondrial malfunction as a pivotal factor contributing to these ailments. Mitochondria play a critical role in powering skeletal muscle activity, but in the context of persistent inflammation, disruptions in their quantity, configuration, and performance have been well-documented. Various disturbances, encompassing alterations in mitochondrial dynamics (such as fission and fusion), calcium regulation, oxidative stress, biogenesis, and the process of mitophagy, are believed to play a central role in the progression of these disorders. Additionally, unfolded protein responses and the accumulation of fatty acids within muscle cells may adversely affect the internal milieu, impairing the equilibrium of mitochondrial functioning. The structural discrepancies between different mitochondrial subsets namely, intramyofibrillar and subsarcolemmal mitochondria likely impact their metabolic capabilities and susceptibility to inflammatory influences. The release of signals from damaged mitochondria is known to incite inflammatory responses. Intriguingly, migrasomes and extracellular vesicles serve as vehicles for intercellular transfer of mitochondria, aiding in the removal of impaired mitochondria and regulation of inflammation. Viral infections have been implicated in inducing stress on mitochondria. Prolonged dysfunction of these vital organelles sustains oxidative harm, metabolic irregularities, and heightened cytokine release, impeding the body's ability to repair tissues. This review provides a comprehensive analysis of advancements in understanding changes in the intracellular environment, mitochondrial architecture and distribution, biogenesis, dynamics, autophagy, oxidative stress, cytokines associated with mitochondria, vesicular structures, and associated membranes in the context of chronic inflammatory musculoskeletal disorders. Strategies targeting key elements regulating mitochondrial quality exhibit promise in the restoration of mitochondrial function, alleviation of inflammation, and enhancement of overall outcomes.

Biologic Adjuvants to Rotator Cuff Repairs Induce Anti-inflammatory Macrophage 2 Polarization and Reduce Inflammatory Macrophage 1 Polarization In Vitro

PURPOSE

To examine the effect of various biologic adjuvants on the polarization of macrophages in an in vitro model for rotator cuff tears.

METHODS

Tissue was harvested from 6 patients undergoing arthroscopic rotator cuff repair. An in vitro model of the supraspinatus and subacromial bursa was created and treated with control, platelet-rich plasma (PRP), autologous activated serum (AAS), or a combination of PRP+AAS. The effect of treatment on macrophage polarization between M1 proinflammatory macrophages or M2 anti-inflammatory macrophages was measured using gene expression, protein expression, flow cytometry, and nitric oxide production.

RESULTS

Tendon and bursa treated with PRP, AAS, and PRP+AAS significantly decreased the gene expression of M1 markers interleukin (IL)-12 and tumor necrosis factor-alpha while significantly increasing the expression of M2 markers arginase, IL-10, and transforming growth factor-β (P < .05) compared with treatment with control. Enzyme-linked immunosorbent assay analysis of protein production demonstrated that, compared with control, coculture treated with PRP, AAS, and PRP+AAS significantly decreased markers of M1-macrophages (IL-6, IL-12, and tumor necrosis factor-alpha) while significantly increasing the expression of markers of M2-macrophages (arginase, IL-10, and transforming growth factor-beta) (P < .05). Flow cytometry analysis of surface markers demonstrated that compared with control, tendon and bursa treated with PRP, AAS, and PRP+AAS significantly decreased markers of M1-macrophages (CD80, CD86, CD64, CD16) while significantly increasing the expression of markers of M2-macrophages (CD163 and CD206) (P < .05). Treatment of the coculture with PRP, AAS, and PRP+AAS consistently demonstrated a decrease in nitric oxide production (P < .05) compared with control. AAS and PRP+AAS demonstrated an increased macrophage shift to M2 compared with PRP alone, whereas there was not as uniform of a shift when comparing PRP+AAS with AAS alone.

CONCLUSIONS

In an in vitro model of rotator cuff tears, the treatment of supraspinatus tendon and subacromial bursa with PRP, AAS, and PRP+AAS demonstrated an increase in markers of anti-inflammatory M2-macrophages and a concomitant decrease in markers of proinflammatory M1-macrophages. AAS and PRP+AAS contributed to a large shift to macrophage polarization to the anti-inflammatory M2 compared with PRP.

CLINICAL RELEVANCE

The mechanism of biologic adjuvant effects on the rotator cuff remains poorly understood. This study suggests that they may contribute to polarization of macrophages for their proinflammatory (M1) state to the anti-inflammatory (M2) state.

Analysis of differentially expressed genes in torn rotator cuff tendon tissues in diabetic patients through RNA-sequencing

BACKGROUND

Rotator cuff tears (RCT) is a common musculoskeletal disorder in the shoulder which cause pain and functional disability. Diabetes mellitus (DM) is characterized by impaired ability of producing or responding to insulin and has been reported to act as a risk factor of the progression of rotator cuff tendinopathy and tear. Long non-coding RNAs (lncRNAs) are involved in the development of various diseases, but little is known about their potential roles involved in RCT of diabetic patients.

METHODS

RNA-Sequencing (RNA-Seq) was used in this study to profile differentially expressed lncRNAs and mRNAs in RCT samples between 3 diabetic and 3 nondiabetic patients. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were performed to annotate the function of the differentially expressed genes (DEGs). LncRNA-mRNA co-expression network and competing endogenous RNA (ceRNA) network were constructed to elucidate the potential molecular mechanisms of DM affecting RCT.

RESULTS

In total, 505 lncRNAs and 388 mRNAs were detected to be differentially expressed in RCT samples between diabetic and nondiabetic patients. GO functional analysis indicated that related lncRNAs and mRNAs were involved in metabolic process, immune system process and others. KEGG pathway analysis indicated that related mRNAs were involved in ferroptosis, PI3K-Akt signaling pathway, Wnt signaling pathway, JAK-STAT signaling pathway and IL-17 signaling pathway and others. LncRNA-mRNA co-expression network was constructed, and ceRNA network showed the interaction of differentially expressed RNAs, comprising 5 lncRNAs, 2 mRNAs, and 142 miRNAs. TF regulation analysis revealed that STAT affected the progression of RCT by regulating the apoptosis pathway in diabetic patients.

CONCLUSIONS

We preliminarily dissected the differential expression profile of lncRNAs and mRNAs in torn rotator cuff tendon between diabetic and nondiabetic patients. And the bioinformatic analysis suggested some important RNAs and signaling pathways regarding inflammation and apoptosis were involved in diabetic RCT. Our findings offer a new perspective on the association between DM and progression of RCT.

Macroporous Granular Hydrogels Functionalized with Aligned Architecture and Small Extracellular Vesicles Stimulate Osteoporotic Tendon-To-Bone Healing

Osteoporotic tendon-to-bone healing (TBH) after rotator cuff repair (RCR) is a significant orthopedic challenge. Considering the aligned architecture of the tendon, inflammatory microenvironment at the injury site, and the need for endogenous cell/tissue infiltration, there is an imminent need for an ideal scaffold to promote TBH that has aligned architecture, ability to modulate inflammation, and macroporous structure. Herein, a novel macroporous hydrogel comprising sodium alginate/hyaluronic acid/small extracellular vesicles from adipose-derived stem cells (sEVs) (MHA-sEVs) with aligned architecture and immunomodulatory ability is fabricated. When implanted subcutaneously, MHA-sEVs significantly improve cell infiltration and tissue integration through its macroporous structure. When applied to the osteoporotic RCR model, MHA-sEVs promote TBH by improving tendon repair through macroporous aligned architecture while enhancing bone regeneration by modulating inflammation. Notably, the biomechanical strength of MHA-sEVs is approximately two times higher than the control group, indicating great potential in reducing postoperative retear rates. Further cell-hydrogel interaction studies reveal that the alignment of microfiber gels in MHA-sEVs induces tenogenic differentiation of tendon-derived stem cells, while sEVs improve mitochondrial dysfunction in M1 macrophages (Mφ) and inhibit Mφ polarization toward M1 via nuclear factor-kappaB (NF-κb) signaling pathway. Taken together, MHA-sEVs provide a promising strategy for future clinical application in promoting osteoporotic TBH.

A Comparison of Clinical Outcomes in Rotator Cuff Re-Tear Patients Who Had Either an Arthroscopic Primary Repair or Arthroscopic Patch Augmentation for Large-to-Massive Rotator Cuff Tears

BACKGROUND AND PURPOSE

Despite the prevalent incidence of re-tear following rotator cuff repair, there is a notable lack of comparative studies investigating the outcomes between patients with re-tear who underwent primary repair versus those who received patch augmentation for large-to-massive tears. We assessed clinical outcomes of these techniques through a retrospective, randomized controlled trial.

METHODS

134 patients diagnosed with large-to-massive rotator cuff tears from 2018 to 2021 underwent surgery; 65 had primary repair and 69 had patch augmentation. A total of 31 patients with re-tears were included, split into two groups; Group A (primary repair, 12 patients) and Group B (patch augmentation, 19 patients). Outcomes were evaluated using several clinical scales and MRI imaging.

RESULTS

Most clinical scores improved postoperatively in both groups. No significant difference in clinical outcomes was observed between groups, except for pain visual analog scale (P-VAS) scores. P-VAS scores showed greater decrease in the patch-augmentation group, a statistically significant difference.

CONCLUSIONS

for large-to-massive rotator cuff tears, patch augmentation led to greater decreases in pain than primary repair, despite similar radiographic and clinical results. Greater tuberosity coverage of the supraspinatus tendon footprint may impact P-VAS scores.

Scapular Kinematics and Patterns of Scapular Dyskinesis in Rotator Cuff Tears: A Prospective Cohort Study

Scapular dyskinesis (SD) is a condition of loss of normal mobility or function of the scapula. SD is frequently observed in patients with other shoulder disorders, such as rotator cuff (RC) tears. This study evaluates the different presentations in clinical outcomes and range of motions (ROMs) in patients suffering from RC tears with and without SD. A total of 52 patients were enrolled, of which 32 patients with RC tears and SD (group A) and 20 patients with RC tears without SD (group B). Statistically significant differences between the groups in terms of clinical outcomes were identified. There were statistically significant differences in terms of flexion (p = 0.019), extension (p = 0.015), abduction (p = 0.005), and external rotation at 90° (p = 0.003) and at 0° (p = 0.025). In conclusion, this prospective study demonstrated that SD influences the clinical presentation of patients with RC tears in terms of clinical outcomes and ROMs, apart from internal rotation. Further studies will need to show whether these differences occur regardless of SD type.

A Validated Three-Dimensional, Heterogenous Finite Element Model of the Rotator Cuff and The Effects of Collagen Orientation

Continuum mechanics-based finite element models of the shoulder aim to quantify the mechanical environment of the joint to aid in clinical decision-making for rotator cuff injury and disease. These models allow for the evaluation of the internal loading of the shoulder, which cannot be measured in-vivo. This study uses human cadaveric rotator cuff samples with surface tendon strain estimates, to validate a heterogeneous finite element model of the supraspinatus-infraspinatus complex during various load configurations. The computational model was considered validated when the absolute difference in average maximum principal strain for the articular and bursal sides for each load condition estimated by the model was no greater than 3% compared to that measured in the biomechanical study. The model can predict the strains for varying infraspinatus loads allowing for the study of load sharing between these two tightly coordinated tendons. The future goal is to use the modularity of this validated model to study the initiation and propagation of rotator cuff tear and other rotator cuff pathologies to ultimately improve care for rotator cuff tear patients.

The tendon unit: biochemical, biomechanical, hormonal influences

The current literature has mainly focused on the biology of tendons and on the characterization of the biological properties of tenocytes and tenoblasts. It is still not understood how these cells can work together in homeostatic equilibrium. We put forward the concept of the "tendon unit" as a morpho-functional unit that can be influenced by a variety of external stimuli such as mechanical stimuli, hormonal influence, or pathological states. We describe how this unit can modify itself to respond to such stimuli. We evidence the capability of the tendon unit of healing itself through the production of collagen following different mechanical stimuli and hypothesize that restoration of the homeostatic balance of the tendon unit should be a therapeutic target.

A qualitative assessment of experiences and perception during pre-admission for rotator cuff repair surgery

BACKGROUND

Rotator Cuff Related Shoulder Pain (RCRSP) is the most common type of shoulder pain and the most disabling common symptom in people with Rotator Cuff Tear (RCT). The patient's point of view concerning health status has become important in decision-making procedures and has therefore been considered a possible criterion standard for assessing treatment efficacy. The study aims to explore patients' experiences and perceptions during pre-admission for Rotator Cuff Repair surgery.

METHODS

A qualitative descriptive study was conducted using a phenomenological approach based on Husserl's philosophical perspective. A consecutive sample of twenty RCT patients awaiting repair surgery agreed to participate and was interviewed until the information was saturated. None of the patients enrolled was lost during the data collection phases. Data were collected through open-ended interviews between December 2021 and January 2022. The credibility, reliability, confirmability, and transferability criteria of Lincoln and Guba have been adopted to guarantee the trustworthiness of the results. The data analysis was conducted according to inductive content analysis.

RESULTS

Four main themes and sub-themes related to each have been identified from the phenomenological analysis. The major themes were: (1) Pain changes lifestyle habits, (2) Pain control requires specific strategies, (3) Suffering turns time into waiting, (4) Waiting for Surgery between trust and fear.

CONCLUSION

Investigating patients' experiences and the emotional impact of Rotator Cuff Tear facilitates the development of specific educational and therapeutic strategies to improve care and post-intervention outcomes.

Histological, radiological and clinical analysis of the supraspinatus tendon and muscle in rotator cuff tears

BACKGROUND

Macroscopic alterations of the affected rotator cuff (RC) are undoubtedly linked to microscopic changes, but they may underestimate the actual degree of the disease. Moreover, it remains unclear whether preoperative structural RC changes may alter clinical outcomes.

METHODS

Supraspinatus tendon and muscle samples were collected from 47 patients undergoing RC surgery. Tendons were evaluated histologically according to the Bonar score; fatty infiltration and muscle atrophy were quantified using a software for biomedical image analysis (ImageJ) in percentage of area affected in the observed muscle section. Preoperative shoulder ROM and pain were evaluated. Radiological muscle atrophy was evaluated with the Tangent Sign and Occupation Ratio; fatty infiltration was assessed according to the Goutallier classification. Correlations between histological, radiological and clinical outcomes were assessed. Statistics were performed using the Spearman correlation coefficient. Intraobserver and interobserver agreement was calculated.

RESULTS

Histopathologic fatty infiltration (r = 0.007, p = 0.962), muscle atrophy (r = 0.003, p = 0.984) and the total Bonar score (r = 0.157, p = 0.292) were not correlated to preoperative shoulder pain. Muscle atrophy showed a significant but weak negative correlation with the preoperative movement of abduction (r = -0.344, p = 0.018). A significant but weak positive correlation was found between muscle atrophy and the total Bonar score (r = 0.352, p = 0.015). No correlation between histological and radiological evaluation was found for both fatty infiltration (r = 0.099, p = 0.510) and muscle atrophy (Tangent Sign: r = -0.223, p = 0.131; Occupation Ratio: r = -0.148, p = 0.319). Our histological evaluation showed a modal value of 3 (out of 3) for fatty infiltration and an equal modal value of 2 and 3 (out of 3) for muscle atrophy. In contrast, the modal value of the Goutallier score was 1 (out of 4) and 28 patients out of 47 showed a negative Tangent sign. At histology, intraobserver agreement ranged from 0.59 to 0.81 and interobserver agreement from 0.57 to 0.64. On the MRI intraobserver agreement ranged from 0.57 to 0.71 and interobserver agreement ranged from 0.53 to 0.65.

CONCLUSIONS

Microscopic muscle atrophy appeared to negatively correlate with the movement of abduction leading to functional impairment. Shoulder pain did not show any relationship with microscopic changes. Radiological evaluation of the supraspinatus muscle alterations seemed to underestimate the degree of the same abnormalities evaluated at histology.

Outcomes after arthroscopic repair of rotator cuff tears in the setting of mild to moderate glenohumeral osteoarthritis

BACKGROUND

Rotator cuff pathology is a very common source of shoulder pain. Similarly, osteoarthritis of the glenohumeral joint can cause shoulder pain and produce similar symptoms. Surgical management can be indicated for both pathologies, however, outcomes data is limited when examining rotator cuff repair (RCR) in the setting of glenohumeral arthritis (GHOA). Thus, this study sought to determine outcomes for patients who undergo RCR in the setting of GHOA.

AIM

To evaluate if a relationship exists between outcomes of RCR in the setting of GHOA.

METHODS

This was a retrospective analysis of patients who underwent arthroscopic rotator cuff repair with concurrent glenohumeral osteoarthritis between 2010-2017. Patients were stratified based on rotator cuff tear size and glenohumeral osteoarthritis severity. Cohorts were paired 1:1 with patients without glenohumeral osteoarthritis. Patients included had a minimum two year follow-up. Rate of conversion to total shoulder arthroplasty, complication rates following initial surgery, and patient-reported outcome measures were collected.

RESULTS

A total of 142 patients were included. The number of patients that required total shoulder arthroplasty within two years after index surgery was low. 2/71 (2.8%) patients with GHOA, and 1/71 (1.4%) without GHOA. Following rotator cuff repair, both groups showed favorable patient-reported outcomes.

CONCLUSION

Patients with glenohumeral osteoarthritis who underwent arthroscopic rotator cuff repair showed comparable outcomes to patients without glenohumeral osteoarthritis.

The Role of Humeral Neck-Shaft Angle in Reverse Total Shoulder Arthroplasty: 155° versus <155°—A Systematic Review

The aim of this study was to have updated scrutiny of the influence of the humeral neck-shaft angle (HNSA) in patients who underwent reverse shoulder arthroplasty (RSA). A PRISMA-guided literature search was conducted from May to September 2021. Clinical outcome scores, functional parameters, and any complications were reviewed. Eleven papers were identified for inclusion in this systematic review. A total of 971 shoulders were evaluated at a minimum-follow up of 12 months, and a maximum of 120 months. The sample size for the "HNSA 155°" group is 449 patients, the "HNSA 145°" group involves 140 patients, and the "HSNA 135°" group comprises 291 patients. The HNSA represents an important variable in choosing the RSA implant design for patients with rotator cuff arthropathy. Positive outcomes are described for all the 155°, 145°, and 135° HSNA groups. Among the different implant designs, the 155° group show a better SST score, but also the highest rate of revisions and scapular notching; the 145° cohort achieve the best values in terms of active forward flexion, abduction, ASES score, and CMS, but also the highest rate of infections; while the 135° design obtains the best results in the external rotation with arm at side, but also the highest rate of fractures. High-quality studies are required to obtain valid results regarding the best prosthesis implant.

Advances in Stem Cell Therapies for Rotator Cuff Injuries

Rotator cuff injury is a common upper extremity musculoskeletal disease that may lead to persistent pain and functional impairment. Despite the clinical outcomes of the surgical procedures being satisfactory, the repair of the rotator cuff remains problematic, such as through failure of healing, adhesion formation, and fatty infiltration. Stem cells have high proliferation, strong paracrine action, and multiple differentiation potential, which promote tendon remodeling and fibrocartilage formation and increase biomechanical strength. Additionally, stem cell-derived extracellular vesicles (EVs) can increase collagen synthesis and inhibit inflammation and adhesion formation by carrying regulatory proteins and microRNAs. Therefore, stem cell-based therapy is a promising therapeutic strategy that has great potential for rotator cuff healing. In this review, we summarize the advances of stem cells and stem cell-derived EVs in rotator cuff repair and highlight the underlying mechanism of stem cells and stem cell-derived EVs and biomaterial delivery systems. Future studies need to explore stem cell therapy in combination with cellular factors, gene therapy, and novel biomaterial delivery systems.

Are there differences in arthroscopic and histological features between traumatic and degenerative rotator cuff tears in elderly patients? A prospective dual-center analysis

Background

Discriminating traumatic rotator cuff tears (RCTs) from degenerative RCTs is sometimes difficult in elderly patients because the prevalence of asymptomatic RCTs increases with age. Little intraoperative information is available on the characteristics of traumatic and degenerative RCTs in elderly patients. The purpose of this study was to compare the arthroscopic findings and histological changes of the coracoacromial ligament (CAL) between traumatic and degenerative RCTs in elderly patients.

Methods

Forty-two shoulders of 42 patients aged ≥ 65 years underwent arthroscopic rotator cuff repair. Nineteen patients had traumatic full-thickness RCTs (Group T), and 23 had degenerative full-thickness RCTs (Group D). The quality of the rotator cuff tissue and the condition of the long head of the biceps were examined. The grade of CAL was evaluated both arthroscopically and histologically. The stiffness of the musculotendinous unit was calculated by measuring the force and displacement using a tensiometer. The arthroscopic and histological findings of the two groups were compared.

Results

Although the mean tendon displacement was comparable, the stiffness was different between Group T and Group D (0.56 ± 0.31 and 1.09 ± 0.67 N/mm, respectively; p < 0.001). Both arthroscopic and histological analysis of the CAL showed that the degenerative changes in the CAL were milder in Group T than in Group D (p < 0.001 and p < 0.001, respectively). There was a moderate positive correlation between the arthroscopic findings of CAL degeneration and the histopathological changes in this ligament (r = 0.47, p = 0.002).

Conclusions

Traumatic RCTs were characterized by preserved elasticity of the musculotendinous unit and milder CAL degeneration compared with degenerative RCTs even in elderly patients.

The Effect of Acromioplasty or Bursectomy on the Results of Arthroscopic Repair of Full Thickness Rotator Cuff Tears: Does the Acromion Type Affect These Results?

Objectives:

The aim of this study was to investigate the effect of subacromial decompression on the results of full thickness rotator cuff repair applied arthroscopically. Examination was also made of the effect of acromion type on the subacromial decompression procedure in patients applied with arthroscopic rotator cuff repair.

Methods:

The study included a total of 150 patients, comprising 102 (68%) females and 48 (32%) males with a full thickness rotator cuff tear repaired arthroscopically. The patients were separated into three groups of 50. Group A comprised those with acromioplasty and bursectomy applied additional to the repair. In Group B, only bursectomy was performed additional to the repair and in Group C, only rotator cuff repair was applied. Evaluation was made of the post-operative long-term pain and functional results.

Results:

The mean age of the cases was 65.63±9.22 years (range, 46–86 years). The affected side was right side in 95 (63.3%) cases and left side in 55 (36.7%). No statistically significant difference was determined between the groups according to the post-operative Constant Murley and ASES scores (p>0.05). In the paired comparisons, the post-operative VAS scores of Group C were higher than those of Groups A and B (p=0.018, p=0.029, p<0.05). No statistically significant difference was determined between Group A and Group B in respect of the post-operative VAS scores (p>0.05).

Conclusion:

In the arthroscopic repair of full thickness rotator cuff tears, neither acromioplasty, coracoacromial ligament loosening nor bursectomy were determined to have any positive effect on the results. Whatever the acromion type, there is no need for an additional subacromial decompression procedure after rotator cuff repair, in respect of pain and functional outcomes. Only acromial spurs should be gently removed paying attention to the coraco-acromial ligament.

Safety and Efficacy of Autologous Dermal Fibroblast Injection to Enhance Healing After Full-Thickness Rotator Cuff Repair: First-in-Human Pilot Study

Background:

There is growing interest in various biological supplements to improve tendon healing in patients after arthroscopic rotator cuff repair. The ideal biological supplement to strengthen rotator cuff remains unknown.

Purpose:

To assess the safety and efficacy of autologous cultured dermal fibroblast (ADF) injection on tendon-to-bone healing in patients after arthroscopic rotator cuff repair.

Study Design:

Case series; Level of evidence, 4.

Methods:

Included were 6 patients who underwent arthroscopic rotator cuff repair between June 2018 and March 2020; all patients had a full-thickness rotator cuff tear (>2 cm) involving the supraspinatus and infraspinatus tendons. The patients were injected with ADF between the repaired tendon and footprint during arthroscopic rotator cuff repair using the suture bridge technique. The safety of ADFs and the procedure was evaluated at 5 weeks postoperatively, and the anatomical healing of the repaired tendon was accessed at 6 months postoperatively using magnetic resonance imaging and at 12 months using ultrasonography. Outcomes including shoulder range of motion (ROM), visual analog scale (VAS) for pain, and functional scores were measured at 6 and 12 months postoperatively.

Results:

Adverse reactions to ADF injection were not observed at 6 months after surgery. VAS and functional scores at 6 and 12 months postoperatively were significantly improved compared with preoperative scores (all P < .05). However, there was no significant difference on any ROM variable between preoperative and postoperative measurements at 6 and 12 months (all P > .05). No healing failure was found at 6 and 12 months postoperatively.

Conclusion:

There was no adverse reaction to ADF injection, and all patients had successful healing after rotator cuff repair. A simple and easily accessible ADF injection may be a novel treatment option for increasing the healing capacity of torn rotator cuff tendons. Further clinical research is needed to verify the study results.

The role of estrogen and progesterone receptors in the rotator cuff disease: a retrospective cohort study

Background

Rotator cuff (RC) tears represent a common cause of shoulder pain and dysfunction in adults. The disease affects primarily women and occurs mainly in the postmenopausal period.

This study aimed to investigate immunohistochemically the presence of estrogen receptor-alpha (ER-⍺), estrogen receptor-beta (ER-β) and progesterone receptor (PR) in the supraspinatus tendon of patients with RC tendinopathy, searching for gender differences of expression. A secondary aim was to evaluate potential links between their expression and the typical histopathological findings of the ailment.

Methods

Biopsies of the supraspinatus tendon were collected intraoperatively from 15 postmenopausal women and 9 men undergoing RC surgery. Specimens were stained with Haematoxylin/Eosin, Masson-Goldner Trichrome, Alcian Blu and immunohistochemical stainings for ER-⍺, ER-β and PR were performed. Tendon alterations were evaluated with the Bonar histopathological scale. Statistical tests used in this study were the Spearman correlation coefficient and the Mann-Whitney U test.

Results

In the supraspinatus tendon, cells expressed ER-⍺ (p = 0.043), ER-β (p = 0.048) and PR (p = 0.004) with statistically significant differences related to age and sex of patients. Immunoreactivity was seen in the nuclei of tenocytes and vascular cells. Postmenopausal women’s samples showed a markedly higher expression of these receptors compared to their male counterpart. There was a positive correlation between the expression of ER-⍺ and ER-β (r = 0.59; p = 0.02) and between ER-β and PR (r = 0.72; p = 0.002) in women’s samples. Furthermore, in postmenopausal women the PR expression decreased with age (r = − 0.56; p = 0.027). Only in women, the ER-β expression positively correlated with the total Bonar histopathological score (p = 0.019) and the ER-β vascular expression positively correlated with ground substance alterations (p = 0.029).

Conclusions

These results reveal that ERs and PR are present in the supraspinatus tendon of patients with RC tears, suggesting a role of sex hormones in the pathogenesis of the disease.

A Historical Analysis of Randomized Controlled Trials in the Management of Pain in Rotator Cuff Tears

The aim of this analysis was to assess the quality of reporting of randomized controlled trials (RCTs) relating to pain management in rotator cuff (RC) tears. This review evaluated the quality of the studies in the literature regarding this topic through the use of some factors and trends. The online databases used to search all RCTs on the topic of RC surgery were Medline, Scopus, CINAHL, EMBASE, and CENTRAL. This research was completed in September 2020. To assess the quality of reports, the Consolidated Standards of Reporting Trials (CONSORT) and the modified Coleman methodology score (MCMS) were used. From the research, 262 articles emerged. Finally, 79 studies were included in this historical analysis. There were no statistically significant changes in MCMS across trials that included or did not include a CONSORT diagram (p = 0.10). A statistically significant difference in MCMS was discovered between papers produced prior to 2009 and publications produced after 2015 (p = 0.03). There was no association between the number of checklist items for each article and the Coleman score. During the years there has been a significant increase in both quantity and quality of RCTs relating to pain in RC tears.

Engineering Musculoskeletal Grafts for Multi-Tissue Unit Repair: Lessons From Developmental Biology and Wound Healing

In the musculoskeletal system, bone, tendon, and skeletal muscle integrate and act coordinately as a single multi-tissue unit to facilitate body movement. The development, integration, and maturation of these essential components and their response to injury are vital for conferring efficient locomotion. The highly integrated nature of these components is evident under disease conditions, where rotator cuff tears at the bone-tendon interface have been reported to be associated with distal pathological alterations such as skeletal muscle degeneration and bone loss. To successfully treat musculoskeletal injuries and diseases, it is important to gain deep understanding of the development, integration and maturation of these musculoskeletal tissues along with their interfaces as well as the impact of inflammation on musculoskeletal healing and graft integration. This review highlights the current knowledge of developmental biology and wound healing in the bone-tendon-muscle multi-tissue unit and perspectives of what can be learnt from these biological and pathological processes within the context of musculoskeletal tissue engineering and regenerative medicine. Integrating these knowledge and perspectives can serve as guiding principles to inform the development and engineering of musculoskeletal grafts and other tissue engineering strategies to address challenging musculoskeletal injuries and diseases.

Conservative versus accelerated rehabilitation after rotator cuff repair: a systematic review and meta-analysis

Background

The purpose of this systematic review and meta-analysis is to compare the conservative and accelerated rehabilitation protocols in patients who underwent arthroscopic rotator cuff repair in terms of clinical outcomes and range of motions at 3, 6, 12, and 24-month follow-up.

Methods

According to PRISMA guidelines, a systematic review of the literature was performed. For each included article, the following data has been extracted: authors, year, study design, level of evidence, demographic characteristics, follow-up, clinical outcomes, range of motions, and retear events. A meta-analysis was performed to compare accelerated versus conservative rehabilitation protocols after arthroscopic rotator cuff repair. The retear rate, postoperative Constant-Murley score and range of motions at 3, 6, 12, and 24 months of follow-up were the outcomes measured.

Results

The search strategy yielded 16 level I-II clinical studies. A total of 1424 patients, with 732 patients and 692 in the accelerated and conservative group, were included. The average age (mean ± standard deviation) was 56.1 ± 8.7 and 56.6 ± 9 in the accelerated and conservative group. The mean follow-up was 12.5 months, ranging from 2 to 24 months. The meta-analysis showed no statistically significant differences in terms of retear rate between the groups (P = 0.29). The superiority of the accelerated group was demonstrated in terms of external rotation (P < 0.05) at 3-month follow-up; in terms of forward elevation, external rotation, abduction (P < 0.05), but not in terms of Constant-Murley score at 6-month follow-up; in terms of forward elevation (P < 0.05) at 12-month follow-up. No significant differences between the two group were highlighted at 24-month follow-up.

Conclusions

No statistically significant differences in the retear rate among the accelerated and conservative group have been demonstrated. On the other hand, statistically and clinically significant differences were found in terms of external rotation at 3 and 6 months of follow-up in favour of the accelerated group. However, no differences between the two groups were detected at 24 months follow-up.

Personalized, Predictive, Participatory, Precision, and Preventive (P5) Medicine in Rotator Cuff Tears

Rotator cuff (RC) disease is a common musculoskeletal disorder of the shoulder entailing pain, with reduced functionality and quality of life. The main objective of this study was to present a perspective of the current scientific evidence about personalized, predictive, participatory, precision, and preventive approaches in the management of RC diseases. The personalized, predictive, participatory, precision and preventive (P5) medicine model is an interdisciplinary and multidisciplinary approach that will provide researchers and clinicians with a comprehensive patrimony of knowledge in the management of RC diseases. The ability to define genetic predispositions in conjunction with the evaluation of lifestyle and environmental factors may boost the tailoring of diagnosis and therapy in patients suffering from RC diseases.

Engineering multi-tissue units for regenerative Medicine: Bone-tendon-muscle units of the rotator cuff

Our body systems are comprised of numerous multi-tissue units. For the musculoskeletal system, one of the predominant functional units is comprised of bone, tendon/ligament, and muscle tissues working in tandem to facilitate locomotion. To successfully treat musculoskeletal injuries and diseases, critical consideration and thoughtful integration of clinical, biological, and engineering aspects are necessary to achieve translational bench-to-bedside research. In particular, identifying ideal biomaterial design specifications, understanding prior and recent tissue engineering advances, and judicious application of biomaterial and fabrication technologies will be crucial for addressing current clinical challenges in engineering multi-tissue units. Using rotator cuff tears as an example, insights relevant for engineering a bone-tendon-muscle multi-tissue unit are presented. This review highlights the tissue engineering strategies for musculoskeletal repair and regeneration with implications for other bone-tendon-muscle units, their derivatives, and analogous non-musculoskeletal tissue structures.

Selected Clinical Features Fail to Predict Inflammatory Gene Expressions for TNF-α, TNFR1, NSMAF, Casp3 and IL-8 in Tendons of Patients with Rotator Cuff Tendinopathy

The pathophysiology of rotator cuff tendinopathy is not fully understood, particularly in terms of the local inflammatory process. This study aimed to investigate the expression of selected molecules in the tumour necrosis factor (TNF)-α transduction pathway, including TNF-α, TNF receptor 1 (TNFR1), neutral sphingomyelinase activation associated factor (NSMAF), caspase 3 (Casp3), and interleukin (IL)-8, in patients with rotator cuff tendinopathy that had undergone surgical treatment. We included 44 participants that underwent arthroscopy, due to rotator cuff tendinopathy. Samples from the injured tendon were collected during arthroscopy, and RT-PCR was performed to determine gene expression. Pearson correlation analyses or U-Mann–Whitney test were performed to identify associations with the following parameters: sex, age at admission, body mass index, the presence of night pain, previous treatment (nonsteroidal anti-inflammatory drugs and/or steroids), medical history of the shoulder injury, upper subluxation of the humeral head, and the number of tendons injured. RT-PCR showed that the selected pro-inflammatory factors involved in the TNF-α signalling pathway expression levels were expressed in the tendon tissues. However, the levels of expression varied from patient to patient. Variations were over 250-fold for TNF-α, about 130-fold for TNFR1, NSMAF, and Casp3, and 1000-fold for IL-8. We could not confirm that any of the clinical parameters investigated were associated with the level of gene expression in the TNF-α pathway and IL-8.

Factors Predicting Frequency and Severity of Postoperative Pain After Arthroscopic Rotator Cuff Repair Surgery

BACKGROUND

Postoperative pain after arthroscopic rotator cuff repair (RCR) is difficult to predict and manage. The experience of pain is thought to be influenced by a range of different factors. Determining which patient factors contribute to the pain may help us to better understand and manage it.

PURPOSE

To evaluate the preoperative patient characteristics that may be predictive of, and correlated with, postoperative pain after arthroscopic RCR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study evaluated 2172 patients who underwent an arthroscopic RCR between February 2004 and December 2015. Pain frequency and severity were measured preoperatively and at 6 weeks after surgery using a modified L'Insalata questionnaire with Likert scales. This 6-week time point was chosen as previous studies have shown patients rank this time point as high in terms of pain after RCR. Logistic regression analysis was conducted to examine the relationship between postoperative pain scores and preoperative pain scores, age, sex, tear size, strength, level of sporting and work activity, and work-related injury status.

RESULTS

The severity of preoperative pain at night (r = 0.33; P < .001), preoperative pain at rest (r = 0.32; P < .001), and frequency of extreme pain (r = 0.31; P < .001) were the strongest independent associations with the frequency of pain at 6 weeks postoperatively. Other associations with postoperative pain frequency included reduced liftoff strength (r = -0.21; P < .001), work-related injury status (P < .001), younger age (P = .001), and female sex (P = .04). Tear size was inversely related with pain severity (R² = 0.85). The severity of preoperative pain had the strongest independent association with the severity of postoperative pain at 6 weeks after surgery (r = 0.35; P < .001). Other associations with postoperative pain severity included increased patient-ranked preoperative stiffness (P < .001), a poorer impression of one's shoulder (P < .001), reduced level of sporting activity (P < .001), and work-related injury status (P < .001).

CONCLUSION

Multiple risk factors have been identified for postoperative pain after RCR, the strongest of which is preoperative pain. However, of note, the magnitude of the correlations between preoperative severity and frequency of pain and postoperative severity and frequency of pain were found to be weak to moderate (r = 0.30-0.35). This suggests that while preoperative pain and its severity are associated with postoperative pain, other factors are likely involved in predicting pain. Smaller tear size, younger age, female sex, and work-related injuries were also associated with postoperative pain at 6 weeks after surgery.

Tendon Extracellular Matrix Assembly, Maintenance and Dysregulation Throughout Life

In his Lissner Award medal lecture in 2000, Stephen Cowin asked the question: "How is a tissue built?" It is not a new question, but it remains as relevant today as it did when it was asked 20 years ago. In fact, research on the organization and development of tissue structure has been a primary focus of tendon and ligament research for over two centuries. The tendon extracellular matrix (ECM) is critical to overall tissue function; it gives the tissue its unique mechanical properties, exhibiting complex non-linear responses, viscoelasticity and flow mechanisms, excellent energy storage and fatigue resistance. This matrix also creates a unique microenvironment for resident cells, allowing cells to maintain their phenotype and translate mechanical and chemical signals into biological responses. Importantly, this architecture is constantly remodeled by local cell populations in response to changing biochemical (systemic and local disease or injury) and mechanical (exercise, disuse, and overuse) stimuli. Here, we review the current understanding of matrix remodeling throughout life, focusing on formation and assembly during the postnatal period, maintenance and homeostasis during adulthood, and changes to homeostasis in natural aging. We also discuss advances in model systems and novel tools for studying collagen and non-collagenous matrix remodeling throughout life, and finally conclude by identifying key questions that have yet to be answered.

Effect of suprascapular nerve injury on rotator cuff enthesis

BACKGROUND

Numerous reports have shown that retracted rotator cuff tears may cause suprascapular nerve injury, and nerve injury causes atrophy and fat accumulation in the rotator cuff muscles. However, the effect of suprascapular nerve injury on rotator cuff enthesis has not been directly defined. This study aimed to investigate the effect of suprascapular nerve injury on rotator cuff enthesis.

METHODS

Twenty-four Wistar albino rats underwent bilateral transection of the suprascapular nerve. Additional 6 rats were used as the sham group. Bilateral supraspinatus and infraspinatus entheses were examined after 1, 4, 8, and 12 weeks of nerve transection. Histomorphometric analyses were performed for each zone of enthesis.

RESULTS

Compared with normal enthesis, significant and consistent decrease in cellularity were observed in the tendon and bone at all time points (P < .001). Collagen bundle diameter in the tendon also decreased in a similar manner (P < .001). Apart from the tendon and bone zones, fibrocartilage and calcified fibrocartilage zones showed similar response, and significant decrease in cellularity was observed 8 weeks after nerve transection (P < .001).

CONCLUSION

This study identifies suprascapular nerve injury as an underlying mechanism leading to compromise of the rotator cuff enthesis structure. Suprascapular nerve injury may be considered as an etiologic factor for the impaired healing after repair of a massive tear.

Family Predisposition for Rotator Cuff Tear and Other Tendinopathies - A Case-Control Study

Objective  To evaluate the prevalence of family history of rotator cuff tear and the presence of tendinopathy in other joints in patients with rotator cuff tears and to compare them with paired controls. To estimate the odds ratio for rotator cuff tear for these two risk factors. Methods  We performed a case-control study comparing patients submitted to treatment for rotator cuff tear with asymptomatic controls. All cases and controls were evaluated by imaging exams and matched by age (±2 years) and gender. We conducted an interview using a standardized questionnaire, and collected data on various risk factors. Results  We evaluated 144 patients, 72 per group. Patients with rotator cuff tears reported a higher number of consanguineous relatives who underwent treatment for the same disease and tendon injuries in other joints compared to the controls ( p  = 0.005 and p  = 0.045 respectively). Individuals with a family history of treatment for rotator cuff tear or with tendinopathies in other joints were more likely to present a rotator cuff tear, with odds ratios of 3.3 (95% confidence interval [95%CI] = 1.4-7.7) and 2.7 (95%CI = 1.1-6.9) respectively. Conclusions  Patients with rotator cuff tear have a higher prevalence of family members with the same disease and tendinopathies or tendon injuries in other joints. The presence of consanguineous relatives with treatment for rotator cuff and tendinopathies in other joints are risk factors for the presence of rotator cuff tears.

Cost-Effectiveness of Supervised versus Unsupervised Rehabilitation for Rotator-Cuff Repair: Systematic Review and Meta-Analysis

Background: The objective of the present study was to compare the efficacy between supervised and unsupervised rehabilitation after rotator-cuff (RC) repair in terms of clinical outcomes, visual-analog-scale (VAS) score, range of motion (ROM), and risk of retear. Material: a comprehensive search of Pubmed, CINAHL, Cochrane, EMBASE, Ovid, and Google Scholar databases through a combination of the following keywords with logical Boolean operators: “informed”, “uninformed”, “unsupervised”, “supervised”, “rehabilitation”, “physical therapy”, “physical therapies”, “postoperative period”, “physical-therapy techniques”, “physical-therapy technique”, “exercise”, “exercise therapy”, “rotator cuff”, “rotator-cuff tear”, and “rotator-cuff repair”. For each article included in the study, the following data were extracted: authors, year, study design, sample size and demographic features, RC tear characteristics, clinical outcomes, ROM, VAS score, retear rate, and time of follow-up. Meta-analysis was performed in terms of VAS score. Results: Four randomized control trials with 132 patients were included. One study demonstrated significant improvement in VAS, active ROM, and the activity of the muscle’s motor units at stop and during maximal effort in supervised patients. Another one showed lower retear rates in the supervised group. The remaining two randomized controlled trials did not reveal any significant differences between supervised and unsupervised rehabilitation in terms of clinical outcomes. Moreover, higher costs were described for supervised rehabilitation. The VAS was not significantly different in the two groups (9.9 compared with 8.25, p = 0.23). Conclusions: although several publications address the problem of RC lacerations, there is a paucity of evidence in the literature regarding the effectiveness of supervised and unsupervised rehabilitation protocols. This systematic review and meta-analysis showed no significant differences between the two types of rehabilitation in terms of VAS scores, while outlining the pros and cons of each protocol.

Genetic factors in rotator cuff pathology: potential influence of col 5A1 polymorphism in outcomes of rotator cuff repair

Background

Investigations in genetics have provided valuable information about the correlation between gene variants and tendinopathy. Single Nucleotide Polymorphisms of COL5A1 gene are reported to be involved in Achilles tendinopathy, chronic degenerative tendon changes at the elbow, and other tendinopathies. The influence of Single Nucleotide Polymorphisms of COL5A1 was previously analyzed in rotator cuff disease with confounding results. Moreover, the rs12722 polymorphism in COL5A1 gene has been implicated in the aetiology of musculoskeletal soft tissue injuries in several association studies. This study aims to analyse the possible influence of rs12722 polymorphism in COL5A1 in the outcomes of rotator cuff repair.

Methods

Seventy-nine patients were included in the study. DNA was extracted from 1.2 ml of venous blood and genotyped for COL5A1 SNPs rs12722. Rotator cuff muscle strength and range of motion (ROM) in anterior elevation, external and internal rotation of the shoulder were evaluated.

Results

Patients presenting COL5A1 SNP rs12722 CC showed a ROM of passive external rotation statistically significantly higher compared to patients with CT genotype and TT genotype.

Conclusions

COL5A1 SNP rs12722 may influence the functional outcomes of RCRs, even though further studies are required to confirm these preliminary results.

Physical therapy and precision rehabilitation in shoulder rotator cuff disease

PURPOSE

To describe the main features of the rehabilitation protocols for RC disease based on the phases of tendon healing and to investigate about the use of wearable devices as monitoring systems.

METHODS

We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL, and EMBASE databases using various combination of the keywords "rotator cuff," "rotator cuff tear," "rehabilitation protocol," "accelerated," "conservative," "stiffness," "exercises," and "wearable devices." All articles concerning precision orthopaedic rehabilitation therapy in rotator cuff disease were retrieved.

RESULTS

To date, rehabilitation protocols are not comparable due to wide heterogeneity of RC diseases. Wearable technologies are becoming a revolutionary tool for movement and posture monitoring.

CONCLUSION

Rehabilitation protocols for RC disease should be tailored on the basis of the different phases of tendon healing. Wearable devices hold the promise to offer a new outlook for long-term follow-up during the postoperative period providing information to the clinician about patient's status.

Arthroscopic rotator cuff repair with and without subacromial decompression is safe and effective: a clinical study

BACKGROUND

Subacromial decompression, that consists of the release of the coracoid-acromial ligament, subacromial bursectomy and anterior-inferior acromioplasty, has traditionally been performed in the management of this pathology. However, the purpose of subacromial decompression procedure is not clearly explained. Our reaserch aimed to analyse the differences among the outcomes of arthroscopic rotator cuff repair (RCR) made with suture anchors, with or without the subacromial decompression procedure.

METHODS

116 shoulders of 107 patients affected by rotator cuff (RC) tear were treated with Arthroscopic RCR. In 54 subjectes, the arthroscopic RCR and the subacromial decompression procedure (group A) were executed, whereas 53 took only arthroscopic RCR (group B). Clinical outcomes were evaluated through the use of the modified UCLA shoulder rating system, Wolfgang criteria shoulder score and Oxford shoulder score (OSS). Functional outcomes were assessed utilizing active and passive range of motion (ROM) of the shoulder, and muscle strength. The duration of the follow up and the configuration of the acromion were used to realize the comparison between the two groups.

RESULTS

In patients with 2 to 5 year follow up, UCLA score resulted greater in group A patients. In subjectes with longer than five years of follow up, group B patients showed considerably greater UCLA score and OSS if related with group A patients. In subjectes that had the type II acromion, group B patients presented a significant greater strength in external rotation.

CONCLUSION

The long term clinical outcomes resulted significantly higher in patients treated only with RCR respect the ones in patients underwent to RCR with subacromial decompression.

Epidemiology of rotator cuff surgery in Italy: regional variation in access to health care. Results from a 14-year nationwide registry

PURPOSE

Rotator cuff (RC) disease is frequent and represents a common source of shoulder pain. The aim of this study is to analyse geographical differences in RC surgeries from 2001 to 2014 in Italy, a country with universal and free health care for its population.

METHODS

An analysis of the Italian National Hospital Discharge records from 2001 to 2014 was performed. These data are anonymous and include patient's age, sex, domicile, region of hospitalization, length of the hospitalization and type of reimbursement (public or private). National and regional population data were obtained from the National Institute for Statistics (ISTAT) for each year.

RESULTS

During the 14-year study period, 390,001 RC repairs were performed in Italy, which represented a mean incidence of 62.1 RC procedures for every 100,000 Italian inhabitants. Nevertheless, the incidence was very different if every single regional population is considered individually. Lombardy resulted to have the highest number of surgeries during the 14-year study period, with 27.95% (108,954) of the total national procedures performed in the 2001-2014 time span. More than half the surgeries (52.00%) were performed in only 3 regions of the northern part of Italy.

CONCLUSIONS

This study shows the existence of geographical disparities in access to RC surgery and patients' necessity to migrate among regions in order to obtain it. Southern regions of Italy are characterized by a lower number of surgeries compared to the northern part of Italy.

Metallic versus biodegradable suture anchors for rotator cuff repair: a case control study

BACKGROUNDS

Repair of full-thickness rotator cuff (RC) tears is routinely performed using suture anchors, which produce secure and effective soft tissue fixation to bone. The aim of this prospective study is to compare the long-term outcomes of single row arthroscopic rotator cuff repair (RCR) performed using metal or biodegradable suture anchors. The null hypothesis is that there is no difference in shoulder function using metal or biodegradable suture anchors as evaluated by UCLA shoulder score, Wolfgang criteria, and Oxford shoulder score.

METHODS

Arthroscopic RCR was performed in 110 patients included in this case control study. They were divided into 2 groups of 51 and 59 patients respectively. Metal suture anchors were used in group 1, and biodegradable suture anchors in group 2. Results were obtained at a mean follow up of 4.05 + 2 years. Clinical outcomes and functional outcomes were evaluated.

RESULTS

The mean modified UCLA shoulder score was 26.9 + 7.1 in group 1, and 27.7 + 6.5 in group 2 (P = 0.5); the mean Wolfgang score was 13.3 + 3.3 in group 1, and 14 + 2.6 in group 2 (P = 0.3); the mean OSS was 23.7 + 11.4 in group 1, and 20.7 + 9.2 points in group 2 (P = 0.1). The mean active anterior elevation was 163.5° + 28.2° in group 1 and 163.6° + 26.9 in group 2 (P = 0.9); the mean active external rotation was 46° + 19.7° in group 1 and 44.6° + 16.3° in group 2 (P = 0.7). The mean strength in anterior elevation was 4.8.02 + 23.52 N in group 1, and 43.12 + 17.64 N in group 2 (P = 0.2); the mean strength in external rotation was 48.02 + 22.54 N in group 1 and 46.06 + 17.64 N in group 2 (P = 0.6); the mean strength in internal rotation was 67.62 + 29.4 N in group 1, and 68.6 + 25.48 N in group 2 (P = 0.9).

CONCLUSIONS

There are no statistically significant differences at a mean follow-up of 4.05 + 2 years in clinical and functional outcomes of single row arthroscopic RCR using metallic or biodegradable suture anchors for RC < 5 cm.

Genetic basis of rotator cuff injury: a systematic review

Background

Rotator cuff disease is a widespread musculoskeletal pathology and a major cause of shoulder pain. Studies on familial predisposition suggest that genetic plays a role in the pathogenesis of rotator cuff disease. Several genes are responsible for rotator cuff disease. The aim of this study was to perform a systematic review on genetic association between rotator cuff disease and genes variations.

Methods

A systematic review of the literature was performed, in accordance with the PRISMA guidelines. PubMed, Medline, CINAHL, Cochrane, Embase and Google Scholar databases were searched comprehensively using the keywords: “Rotator cuff”, “Gene”, “Genetic”, “Predisposition”, “Single-nucleotide polymorphism” and “Genome-wide association”.

Results

8 studies investigating genes variations associated with rotator cuff tears were included in this review. 6 studies were case-control studies on candidate genes and 2 studies were GWASs. A significant association between SNPs and rotator cuff disease was found for DEFB1, FGFR1, FGFR3, ESRRB, FGF10, MMP-1, TNC, FCRL3, SASH1, SAP30BP, rs71404070 located next to cadherin8. Contradictory results were reported for MMP-3.

Conclusion

Further investigations are warranted to identify complete genetic profiles of rotator cuff disease and to clarify the complex interaction between genes, encoded proteins and environment. This may lead to individualized strategies for prevention and treatment of rotator cuff disease.

Level of evidence

Level IV, Systematic Review.

Therapeutic potential of exosomes in rotator cuff tendon healing

Rotator cuff tears are common musculoskeletal injuries that can cause significant pain and disability. While the clinical results of rotator cuff repair can be good, failure of tendon healing remains a significant problem. Molecular mechanisms underlying structural failure following surgical repair remain unclear. Histologically, enhanced inflammation, disorganization of the collagen fibers, calcification, apoptosis and tissue necrosis affect the normal healing process. Mesenchymal stem cells (MSCs) have the ability to provide improved healing following rotator cuff repair via the release of mediators from secreted 30-100 nm extracellular vesicles called exosomes. They carry regulatory proteins, mRNA and miRNA and have the ability to increase collagen synthesis and angiogenesis through increased expression of mRNA and release of proangiogenic factors and regulatory proteins that play a major role in proper tissue remodeling and preventing extracellular matrix degradation. Various studies have shown the effect of exosomes on improving outcome of cutaneous wound healing, scar tissue formation, degenerative bone disease and Duchenne Muscular Dystrophy. In this article, we critically reviewed the potential role of exosomes in tendon regeneration and propose the novel use of exosomes alone or seeded onto biomaterial matrices to stimulate secretion of favorable cellular factors in accelerating the healing response following rotator cuff repair.

Sleep Disturbance and Rotator Cuff Tears: A Systematic Review

Background and Objectives: Sleep disorders are one of the most common complaints of patients with rotator cuff (RC) tears. However, potential correlations between the treatment of RC tears and the causal factors of sleep disorders are still under discussion. The aim of this review is to evaluate quality of sleep in patients before and after surgery for RC tears and to identify which factors affected patients’ sleep. Materials and Methods: A systematic review was conducted. To provide high quality of the review, the included studies were evaluated with the standardized tool “Quality Assessment Tool for Quantitative Studies” developed by the Effective Public Health Practice Project. Results: The search strategy yielded 78 articles. After duplicate removal and titles, abstracts and full-texts review, four studies were included in the systematic review. Concerning shoulder function, the most frequently reported scale was the Simple Shoulder Test (SST). Regarding sleep quality, the most frequently reported score was the Pittsburgh Sleep Quality Index (PSQI). Conclusion: We found that the majority of patients with RC tears had a sleep disturbance, especially before surgery with a general improvement in sleep quality post-operatively. Moreover, sleep quality was correlated with pain and it also seems that factors as comorbidities, obligatory position during night time, preoperative and prolonged postoperative use of narcotics and psychiatric issues may play an important role in sleep quality.

Conservative Rehabilitation Provides Superior Clinical Results Compared to Early Aggressive Rehabilitation for Rotator Cuff Repair: A Retrospective Comparative Study

Background and objectives: To compare the long term clinical outcomes, range of motion (ROM) and strength of two different postoperative rehabilitation protocols after arthroscopic rotator cuff repair (RCR) for full-thickness rotator cuff (RC) tears. Materials and Methods: Patients undergoing RCR were divided into two groups. In 51 patients (56 shoulders), rehabilitation was performed without passive external rotation, anterior elevation ROM, and active pendulum exercises in the first 2 weeks after surgery (Group A). In 49 patients (50 shoulders) aggressive rehabilitation was implemented, with early free passive external rotation, anterior elevation ROM, and active pendulum exercises were allowed from the day after surgery (Group A). Results: No statistically significant differences were found in clinical scores, muscle strength, passive forward flexion, passive and active internal/external rotation between the two groups. However, the mean active forward flexion was 167.3° ± 26° (range 90–180°) in group A and 156.5° ± 30.5° (range 90–180°) in group B (p = 0.04). Conclusions: A statistically significant difference between the 2 groups was found in active forward flexion ROM, which was better in patients of group A.

Rationale for Biologic Augmentation of Rotator Cuff Repairs

The structural integrity of rotator cuff repair (RCR) has been a primary focus for shoulder surgeons seeking long-term clinical and functional success. Improvements in surgical techniques have allowed for superior initial biomechanical fixation. However, tendon healing remains a significant clinical problem even after rigid time-zero repair. The lack of long-term healing has led to increased interest in biologic augmentation to improve tendon-to-bone healing. This interest has led to a rise in the investigation of small molecular therapies, cell-based strategies, and tissue-derived treatments offering surgeons a new therapeutic toolbox for potentially improving RCR long-term outcomes. However, the delivery, efficacy, and safety of these treatments remain under investigation. Additional well-designed, high-level studies are of paramount importance in creating evidence-based guidelines for the implementation of new biologic solutions. This review article discusses the current preclinical, translational, and clinical experience with and rationale for biologic augmentation in RCR.

Immunohistochemical features of rotator cuff tendinopathy

BACKGROUND

Rotator cuff tendinopathy is a common musculoskeletal ailment in sedentary and athletic individuals. Various mediators of inflammation have been detected in human tendons: they are thought to initiate or progress the course of tendinopathy.

SOURCES OF DATA

An online search was conducted using AMED, CINAHL, Embase, The Cochrane Library, PEDro and Pubmed, using the terms tendinopathy, tendon, tendinitis, tendinosis, histology, histopathology, immunohistochemistry, immunohistochemical, rotator cuff and pain.

AREAS OF AGREEMENT

Histological examination of tendinopathic tendons shows degeneration of the collagen structure and infiltration of fat and vessels, together with increased expression of inflammatory cytokines, MMP-1, 2, 3, 9, 13, vascular endothelial growth factor and Hypoxia inducible factor (HIF).

AREAS OF CONTROVERSY

Most of the studies about this topic exhibited limited validity because of lack of appropriately matched controls and no inclusion or exclusion criteria. The evidence associated with the histopathological analysis of the rotator cuff is limited.

GROWING POINTS

The histochemical and immunohistochemical features of rotator cuff tendinopathy are still unclear. A thorough understanding of the vascularity, innervation and biochemical mediators of pain could be used to target rotator cuff pathology, and possibly guide the therapy of painful rotator cuff disorders.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is a need for a validated reproducible method of rotator cuff tendon biopsy evaluation. We require further studies with improved designs to effectively evaluate the histological and immunohistochemical features of rotator cuff tendinopathy.

Cryotherapy or gradual reloading exercises in acute presentations of rotator cuff tendinopathy: a randomised controlled trial

Objectives

Rotator cuff tendinopathies are the most common shoulder disorders. As persistent symptoms lasting more than 3 months have been shown to be a strong indicator of poor outcomes, it is important to have successful interventions in the acute stage. However, there is no evidence yet to guide clinical interventions in an acute pain context. The objective of this study was to compare the short-term effect of a 2-week gradual reloading exercises programme with the use of cryotherapy on symptoms and function for acute rotator cuff tendinopathy.

Methods

This simple-blind, randomised controlled trial included 44 participants with acute rotator cuff tendinopathy who were randomly allocated to either the exercises or cryotherapy group. Symptoms and functional limitations were evaluated at weeks 0, 2 and 6 using self-reported questionnaires (Disabilities of the Arm, Shoulder and Hand, Western Ontario Rotator Cuff, and Brief Pain Inventory), while acromiohumeral distance, shoulder strength and active range of motion were evaluated at weeks 0 and 2.

Results

Following interventions, both groups showed statistically significant improvements on symptoms and function at week 2 and week 6 compared with baseline. However, there was no significant group × time interaction. There was no time effect on acromiohumeral distance, shoulder strength and active range of motion, as well as no time × group interaction.

Conclusion

The results showed a statistically significant improvement in symptoms and function in both groups, but there was no difference between the short-term effect of a cryotherapy based-approach and a gradual reloading exercises programme.

Trial registration number

NCT02813304.

Genetics of rotator cuff tears: no association of col5a1 gene in a case-control study

Background

The incidence of RC tears increases with aging, affecting approximately 30 to 50% of individuals older than 50 years, and more than 50% of individuals older than 80 years. Intrinsic factors (age or gender), extrinsic factors (sports activity or occupation), and biological factors were identified in the onset and progression of RC tears. The attention in the study of aetiology of RC tendinopathy has shifted to the identification of gene variants. Genes encoding for proteins regulating the concentration of pyrophosphate in the extracellular matrix and genes encoding for fibroblastic growth factors, defensin beta 1 and estrogen-related receptor-beta were analyzed. However, only in one study the role of variants of collagen type V alpha 1 (col5a1) gene in RC tears was assessed. The objective of this study was to determine whether a col5a1 DNA sequence variant, rs12722 (C/T) was associated with rotator cuff (RC) tears in a case-control study.

Methods

The study included 93 Caucasian patients undergoing surgery for RC tears and 206 patients with no history and sign of RC disease as evaluated by MRI. Patients were divided into two groups. Group 1 included patients with RC tear diagnosed on clinical and imaging grounds and confirmed at the time of surgery. Group 2 (control group) included patients without history or clinical symptoms of RC disorders and with a MRI negative for RC disease. DNA was obtained from approximately 1.2 ml of venous blood using the MagCore extractor system H16 with a MagCore Genomic DNA Large Volume Whole Blood Kit (RBC Bioscience Corp., Taiwan). All study participants were genotyped for SNPs rs12722.

Results

We first estimated that our study had 92% power at p < 0.05 to detect a genetic effect size of 2.05 in the RT tears (93 individuals) and healthy population (206 individuals) cohorts, assuming a minor allele frequency for col5a1 variant rs12722 of 0.5707 in the Italian population (gnomAD frequency). No significant difference in allele and genotype frequencies was observed between RT tears patients and healthy controls. Similarly, no significant association was seen between the RT tears and healthy controls participants in the combined genotype distributions.

Conclusion

In conclusion, no correlations between the SNP rs12722 of col5a1 gene and RC tears susceptibility was found.

Evaluating the role of subacromial impingement in rotator cuff tendinopathy: Development and analysis of a novel murine model

Subacromial impingement of the rotator cuff is understood as a contributing factor in the development of rotator cuff tendinopathy. However, changes that occur in the impinged tendon are poorly understood and warrant further study. To enable further study of rotator cuff tendinopathy, we performed a controlled laboratory study to determine feasibility and baseline characteristics of a new murine model for subacromial impingement. This model involves surgically inserting a microvascular clip into the subacromial space in adult C57Bl/6 mice. Along with a sham surgery arm, 90 study animals were distributed among time point groups for sacrifice up to 6 weeks. All animals underwent bilateral surgery (total N = 180). Biomechanical, histologic, and molecular analyses were performed to identify and quantify the progression of changes in the supraspinatus tendon. Decreases in failure force and stiffness were found in impinged tendon specimens compared to sham and no-surgery controls at all study time points. Semi-quantitative scoring of histologic specimens demonstrated significant, persistent tendinopathic changes over 6 weeks. Quantitative real-time polymerase chain reaction analysis of impinged tendon specimens demonstrated persistently increased expression of genes related to matrix remodeling, inflammation, and tendon development. Overall, this novel murine subacromial impingement model creates changes consistent with acute tendonitis, which may mimic the early stages of rotator cuff tendinopathy. A robust, simple, and reproducible animal model of rotator cuff tendinopathy is a valuable research tool to allow further studies of cellular and molecular mechanisms and evaluation of therapeutic interventions in rotator cuff tendinopathy. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2780-2788, 2018.

The effectiveness of conservative and surgical treatment for shoulder stiffness: a systematic review of current literature

INTRODUCTION

Currently, no therapeutic intervention is universally accepted, and the most effective management for restoring motion and diminishing pain in patients with shoulder stiffness has yet to be defined. This systematic review analyses outcomes of conservative and surgical interventions to treat shoulder stiffness.

SOURCE OF DATA

A systematic review of literature according to the PRISMA guidelines was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, Ovid and Google Scholar databases using various combinations of the keywords 'shoulder', 'shoulder stiffness', 'stiff shoulder', 'conservative', since inception of databases to June 2018 was performed.

AREAS OF AGREEMENT

Shoulder stiffness could be treated with conservative means including nonsteroidal anti-inflammatory medications, corticosteroid injections, or transcutaneous electrical nerve stimulation, manipulation under anaesthesia, and arthroscopic capsular release.

AREAS OF CONTROVERSY

No therapeutic intervention is universally accepted, and the most effective management to restore motion and diminish pain in patients with shoulder stiffness has yet to be defined.

GROWING POINTS

The rate of failure after treatment for stiff shoulder is higher in the surgical group than in the conservative group.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is insufficient evidence to establish whether surgical or conservative management is the best choice to manage shoulder stiffness. Prospective, randomized studies are needed to establish whether surgical or conservative management produce a clinically relevant difference in functional outcome.

Missed fractures of the greater tuberosity

Background

Fractures of the greater tuberosity may result from a variety of mechanisms. Missed injury remains a persistent problem, both from a clinical and medico-legal point-of-view. Few studies on this topic are available in the literature. We present the clinical and radiological findings of a consecutive series of 17 patients who were diagnosed and managed with undisplaced greater tuberosity fractures.

Methods

A retrospective study of a consecutive series of 17 patients who sustained an occult greater tuberosity fracture were performed. Patients sustained a traumatic occult greater tuberosity fracture, underwent shoulder radiographs after trauma in 5 days and they were diagnosed as negative by a consultant radiologist. All patients received a standard assessment using MRI (Magnetic Resonance Imaging) scans Each patient was evaluated for arm dominance, trauma history, duration and type of symptoms and post-treatment Oxford Shoulder Score.

Results

At the final follow up the mean OSS (Oxford Shoulder Score) was 38.3 (range 17–46; SD 9.11). Three patients required a glenohumeral joint injection for post-traumatic pain and stiffness and three patients required subacromial decompression for post-traumatic impingement.

Conclusions

Though undisplaced greater tuberosity fracture can be managed non-operatively with good results, patients with persistent post-traumatic shoulder pain, tenderness and limitation of shoulder function warrant investigation with MRI to identify occult fractures. Prompt identification of these fractures can facilitate patient treatment and counselling, avoiding a source of patient dissatisfaction and litigation.

Growth factor delivery strategies for rotator cuff repair and regeneration

The high incidence of degenerative tears and prevalence of retears (20-95%) after surgical repair makes rotator cuff injuries a significant health problem. This high retear rate is attributed to the failure of the repaired tissue to regenerate the native tendon-to-bone insertion (enthesis). Biological augmentation of surgical repair such as autografts, allografts, and xenografts are confounded by donor site morbidity, immunogenicity, and disease transmission, respectively. In contrast, these risks may be alleviated via growth factor therapy, which can actively influence the healing environment to promote functional repair. Several challenges have to be overcome before growth factor delivery can translate into clinical practice such as the selection of optimal growth factor(s) or combination, identification of the most efficient stage and duration of delivery, and the design considerations for the delivery device. Emerging insight into the injury-repair microenvironment and our understanding of growth factor mechanisms in healing are informing the design of advanced delivery scaffolds to effectively treat rotator cuff tears. Here, we review potential growth factor candidates, design parameters and material selection for growth factor delivery, innovative and dynamic delivery scaffolds, and novel therapeutic targets from tendon and developmental biology for the structural and functional healing of rotator cuff repair.

Matrix Metalloproteases 1 and 3 Promoter Gene Polymorphism Is Associated With Rotator Cuff Tear

BACKGROUND

Studies suggest that the collagen degeneration and disordered arrangement of collagen fibers in rotator cuff tears are associated with an increase in activity of matrix metalloproteases 1 and 3 (MMP-1 and MMP-3), and that MMP activity may be in part genetically mediated. The degree to which this might be clinically relevant in patients with rotator cuff tears has not been well characterized.

QUESTIONS/PURPOSES

(1) Is genetic polymorphism of MMP-1 and MMP-3 associated with rotator cuff tears? (2) Are there haplotypes of MMP-1 and MMP-3 correlated with rotator cuff tears? (3) Compared with control subjects, do patients with rotator cuff tears have a higher proportion of relatives with the same disease?

METHODS

We evaluated 64 patients with full-thickness rotator cuff tears and 64 asymptomatic control subjects. Patients younger 65 years, with nontraumatic tears, were included. The tear or integrity of the rotator cuff tear was evaluated by MRI or ultrasonography in all individuals. The patients and control subjects were paired by age. MMP-1 and MMP-3 genotypes were determined using the PCR-restriction fragment length polymorphism assays.

RESULTS

Genetic polymorphisms in MMP-1 and MMP-3 are associated with rotator cuff tear, in which individuals with rotator cuff tears have associated genotypes 1G/2G (patients, 32 of 64 [50%], control subjects, 16 of 64 [25%]; odds ratio [OR], 4.8; 95% CI, 2.1-11.0; p < 0.001) and 2G/2G were at great risk (patients, 15 of 64 [23%], control subjects, seven of 64 [11%]; OR, 5.2; 95% CI,1.8-14.9; p < 0.001), and patients with rotator cuff tears were associated with a higher proportion of 2G allele distribution (62 of 128 [48%] versus 30 of 128 [23%]; p < 0.001). Patients with the 5A/5A genotype are at greater risk of rotator cuff tear (patients, 15 of 64 [23%]; control subjects, four of 64 [6%]; OR, 5.5; 95% CI, 1.4-20.9; p = 0.021), and there was higher 5A allele distribution in patients with rotator cuff tears (patients, 68 of 128 [53%]; control subjects, 52 of 128 [41%]; p = 0.045). Individuals with the haplotype 2G/5A were more likely to have rotator cuff tears develop (patients, 42 of 64 [66%]; control subjects, 17 of 64 [27%]; OR, 5.3; 95% CI, 2.5-11.3; p < 0.001). Patients with rotator cuff tears reported, in higher number, the existence of relatives who previously had treatment for rotator cuff tears (19 of 64 [30%] versus four of 64 [6%]; OR, 6.3; 95% CI, 2.0-19.9; p = 0.001).

CONCLUSIONS

The genetic polymorphism of MMP-1 and MMP-3 is associated with rotator cuff tear. Individuals with haplotype 2G/5A were more susceptible to rotator cuff tears in the population studied.

CLINICAL RELEVANCE

Knowledge of the genetic markers related to rotator cuff tears can enable identification of susceptible individuals and increase understanding of the pathogenesis of tendon degeneration.

IL-10 ameliorates TNF-α induced meniscus degeneration in mature meniscal tissue in vitro

Background

Joint inflammation causes meniscus degeneration and can exacerbate post-traumatic meniscus injuries by extracellular matrix degradation, cellular de-differentiation and cell death. The aim of this study was to examine whether anti-inflammatory interleukin-10 exerts protective effects in an in vitro model of TNF-α-induced meniscus degeneration.

Methods

Meniscus tissue was harvested from the knees of adult cows. After 24 h of equilibrium explants were simultaneously treated with bovine TNF-α and IL-10. After an incubation time of 72 h cell death was measured histomorphometrically (nuclear blebbing, NB) and release of glycosaminoglycans (GAG, DMMB assay) and nitric oxide (NO, Griess-reagent) were analysed. Transcription levels (mRNA) of matrix degrading enzymes, collagen type X (COL10A1) and nitric oxide synthetase 2 (NOS2) were measured by quantitative real time PCR. TNF-α-dependent formation of the aggrecanase-specific aggrecan neoepitope NITEGE was visualised by immunostaining. Differences between groups were calculated using a one-way ANOVA with a Bonferroni post hoc test.

Results

Administration of IL-10 significantly prevented the TNF-α-related cell death (P .001), release of NO (P .003) and NOS2 expression (P .04). Release of GAG fragments (P .001), NITEGE formation and expression of MMP3 (P .007), -13 (P .02) and ADAMTS4 (P .001) were significantly reduced. The TNF-α-dependent increase in COL10A1 expression was also antagonized by IL-10 (P .02).

Conclusion

IL-10 prevented crucial mechanisms of meniscal degeneration induced by a key cytokine of OA, TNF-α. Administration of IL-10 might improve the biological regeneration and provide a treatment approach in degenerative meniscus injuries and in conditions of post-traumatic sports injuries.