Vascularity and tendon pathology in the rotator cuff: a review of literature and implications for rehabilitation and surgery

Shoulder mobility and strength impairments in patients with rotator cuff related shoulder pain: a systematic review and meta analysis

Background

The methods previously proposed in the literature to assess patients with rotator cuff related shoulder pain, based on special orthopedic tests to precisely identify the structure causing the shoulder symptoms have been recently challenged. This opens the possibility of a different way of physical examination.

Objective

To analyze the differences in shoulder range of motion, strength and thoracic kyphosis between rotator cuff related shoulder pain patients and an asymptomatic group.

Method

The protocol of the present research was registered in the International Prospective Register of Systematic Review (PROSPERO) (registration number CRD42021258924). Database search of observational studies was conducted in MEDLINE, EMBASE, WOS and CINHAL until July 2023, which assessed shoulder or neck neuro-musculoskeletal non-invasive physical examination compared to an asymptomatic group. Two investigators assessed eligibility and study quality. The Newcastle Ottawa Scale was used to evaluate the methodology quality.

Results

Eight studies (N = 604) were selected for the quantitative analysis. Meta-analysis showed statistical differences with large effect for shoulder flexion (I2 = 91.7%, p < 0.01, HG = -1.30), external rotation (I2 = 83.2%, p < 0.01, HG = -1.16) and internal rotation range of motion (I2 = 0%, p < 0.01, HG = -1.32). Regarding to shoulder strength; only internal rotation strength showed statistical differences with small effect (I2 = 42.8%, p < 0.05, HG = -0.3).

Conclusions

There is moderate to strong evidence that patients with rotator cuff related shoulder pain present less shoulder flexion, internal and external rotation range of motion and less internal rotation strength than asymptomatic individuals.

Finite Element Model of the Shoulder with Active Rotator Cuff Muscles: Application to Wheelchair Propulsion

The rotator cuff is prone to injury, remarkably so for manual wheelchair users. To understand its pathomechanisms, finite element models incorporating three-dimensional activated muscles are needed to predict soft tissue strains during given tasks. This study aimed to develop such a model to understand pathomechanisms associated with wheelchair propulsion. We developed an active muscle model associating a passive fiber-reinforced isotropic matrix with an activation law linking calcium ion concentration to tissue tension. This model was first evaluated against known physiological muscle behavior; then used to activate the rotator cuff during a wheelchair propulsion cycle. Here, experimental kinematics and electromyography data was used to drive a shoulder finite element model. Finally, we evaluated the importance of muscle activation by comparing the results of activated and non-activated rotator cuff muscles during both propulsion and isometric contractions. Qualitatively, the muscle constitutive law reasonably reproduced the classical Hill model force-length curve and the behavior of a transversally loaded muscle. During wheelchair propulsion, the deformation and fiber stretch of the supraspinatus muscle-tendon unit pointed towards the possibility for this tendon to develop tendinosis due to the multiaxial loading imposed by the kinematics of propulsion. Finally, differences in local stretch and positions of the lines of action between activated and non-activated models were only observed at activation levels higher than 30%. Our novel finite element model with active muscles is a promising tool for understanding the pathomechanisms of the rotator cuff for various dynamic tasks, especially those with high muscle activation levels.

Protective and Regenerative Effects of Reconstituted HDL on Human Rotator Cuff Fibroblasts under Hypoxia: An In Vitro Study

Hypoxia and hypo-high-density lipoproteinemia (hypo-HDLemia) are proposed risk factors for rotator cuff tear. HDL is recognized for its potential benefits in ischemia-driven angiogenesis and wound healing. Nevertheless, research on the potential benefits of reconstituted HDL (rHDL) on human rotator cuff fibroblasts (RCFs) under hypoxia is limited. This study investigates the cytoprotective and regenerative effects of rHDL, as well as N-acetylcysteine (NAC), vitamin C (Vit C), and HDL on human RCFs under hypoxic conditions. Sixth-passage human RCFs were divided into normoxia, hypoxia, and hypoxia groups pretreated with antioxidants (NAC, Vit C, rHDL, HDL). Hypoxia was induced by 1000 µM CoCl2. In the hypoxia group compared to the normoxia group, there were significant increases in hypoxia-inducible factor-1α (HIF-1α), heme oxygenase-1 (HO-1), and Bcl-2/E1B-19kDa interacting protein 3 (BNIP3) expressions, along with reduced cell viability, elevated reactive oxygen species (ROS) production, apoptosis rate, expressions of cleaved caspase-3, cleaved poly ADP-ribose polymerase-1 (PARP-1), vascular endothelial growth factors (VEGF), and matrix metalloproteinase-2 (MMP-2), as well as decreased collagen I and III production, and markedly lower cell proliferative activity (p ≤ 0.039). These responses were significantly mitigated by pretreatment with rHDL (p ≤ 0.046). This study suggests that rHDL can enhance cell proliferation and collagen I and III production while reducing apoptosis in human RCFs under hypoxic conditions.

Rotator Cuff Tears Are Related to the Side Sleeping Position

Purpose

To determine whether there was a relationship between sleep position and symptomatic partial- and full-thickness rotator cuff tears.

Methods

A consecutive series of patients that met the inclusion/exclusion criteria (n = 58) were in seen in clinic between July 2019 and December 2019. All of these individuals had a significant partial-thickness (> 50%) or full-thickness rotator cuff tear determined by either ultrasound, magnetic resonance imaging, or both. All patients in this series either had an insidious onset of shoulder pain or their symptoms were related to the basic wear and tear of daily activities. Traumatic rotator cuff tears (those associated with a significant traumatic event such as shoulder instability, motor vehicle accidents, sports related injuries, etc.) were excluded. Previous shoulder surgery, recurrent rotator cuff tears, and worker's compensation cases also were excluded from this series. As part of the history-taking process, the patients were asked what was their preferred sleeping position-side sleeper, back sleeper, or stomach sleeper. A χ2 test was conducted to determine the relationship between rotator cuff pathology and sleep position.

Results

Of the 58 subjects, 52 of the patients were side sleepers, 4 were stomach sleepers, 1 was a back sleeper, and 1 preferred all 3 positions. Statistical analysis, using the χ2 test (P < .0001), demonstrated that rotator cuff tears were most often seen in side sleepers.

Conclusions

In our study, there appeared to be a relationship between the preference of being a side sleeper and the presence of a rotator cuff tear.

Level of Evidence

Level IV, prognostic case series.

Targeting Senescent Tendon Stem/Progenitor Cells to Prevent or Treat Age-Related Tendon Disorders

Age-related tendon disorder, a primary motor system disease, is characterized by biological changes in the tendon tissue due to senescence and seriously affects the quality of life of the elderly. The pathogenesis of this disease is not well-understood. Tendon stem/progenitor cells (TSPCs) exhibit multi-differentiation capacity. These cells are important cellular components of the tendon because of their roles in tendon tissue homeostasis, remodeling, and repair. Previous studies revealed alterations in the biological characteristics and tenogenic differentiation potential of TSPCs in senescent tendon tissue, in turn contributing to insufficient differentiation of TSPCs into tenocytes. Poor tendon repair can result in age-related tendinopathies. Therefore, targeting of senescent TSPCs may restore the tenogenic differentiation potential of these cells and achieve homeostasis of the tendon tissue to prevent or treat age-related tendinopathy. In this review, we summarize the biological characteristics of TSPCs and histopathological changes in age-related tendinopathy, as well as the potential mechanisms through which TSPCs contribute to senescence. This information may promote further exploration of innovative treatment strategies to rescue TSPCs from senescence.

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.

Current understanding of the diagnosis and management of the tendinopathy: An update from the lab to the clinical practice

Tendinopathy is labeled by many authors as a troublesome, common pathology, present in up to 30% medical care consultations involving musculoskeletal conditions. Despite the lasting interest for addressing tendon pathology, current researchers agree that even the exact definition of the term tendinopathy is unclear. Tendinopathy is currently diagnosed as a clinical hypothesis based on the patient symptoms and physical context. One of the main goals of current clinical management is to personalize treatment approaches to adapt them to the many different needs of the population. Tendons are complex structures that unite muscles and bones with two main objectives: to transmit forces and storage and release energy. Regarding the tensile properties of the tendons, several authors argued that tendons have higher tensile strength compared with muscles, however, are considered less flexible. Tendinopathy is an accepted term which is used to indicated a variety of tissue conditions that appear in injured tendons and describes a non-rupture damage in the tendon or paratendon, which is intensified with mechanical loading Even when the pathoetiology of tendinopathy is unclear, there is a wide array of treatments available to treat and manage tendinopathy. Although tendinitis usually debuts with an inflammatory response, the majority of chronic tendinopathies do not present inflammation and so the choosing of treatment should vary depending on severity, compliance, pain and duration of symptoms. The purpose of this article is to review and provide an overview about the currently research of the tendon diagnosis, management and etiology.

The Regenerative Role of Gelatin in PLLA Electrospun Membranes for the Treatment of Chronic Massive Rotator Cuff Injuries

Failing to regenerate native tendon tissue in chronic massive rotator cuff tears (CMRCTs) results in high retear rates after surgery. Gelatin is a hydrolyzed form of collagen which is bioactive and biocompatible. This study intends to investigate the suitability of integrating gelatin to poly (l-lactic acid) (PLLA) fibrous membranes for promoting the healing of CMRCTs. PLLA/Gelatin electrospun membranes (PGEM) are fabricated using electrospinning technology. The fourier transform infrared, static contact angles are tested sequentially. Cytocompatibility is evaluated with rat tendon fibroblasts and human umbilical endothelial cells (HUEVCs) lines. CMRCTs rat models are established and assigned into three groups (the sham group, the repaired group, and the augmentation group) to perform histomorphological and biomechanical evaluations. Gelatin is successfully integrated into PLLA fibrous membranes by the electrospinning technique. In vitro studies indicate that PGEM shows a great cytocompatibility for rat tendon fibroblasts and HUEVCs. In vivo studies find that applications of PGEM significantly promote well-aligned collagen I fibers formation and enhance biomechanical properties of the repaired tendon in CMRCTs rat models. In summary, gelatin promotes tendon fibroblasts and HUEVCs adhesion, migration, and proliferation on the PLLA fibrous membranes, and PGEM may provide a great prospect for clinical application.

Factors Associated With Symptomatic Rotator Cuff Tears: The Rotator Cuff Outcomes Workgroup Cohort Study

OBJECTIVE

Although rotator cuff tear is one of the most common musculoskeletal disorders, its etiology is poorly understood. We assessed factors associated with the presence of rotator cuff tears in a cohort of patients with shoulder pain.

DESIGN

From February 2011 to July 2016, a longitudinal cohort of patients with shoulder pain was recruited. Patients completed a detailed questionnaire in addition to a magnetic resonance imaging scan and a clinical shoulder evaluation. The association of multiple factors associated with rotator cuff tears was assessed using multivariate logistic regression.

RESULTS

In our cohort of 266 patients, 61.3% of patients had a rotator cuff tear. Older age (per 1 yr: odds ratio = 1.03, 95% confidence interval = 1.02-1.07), involvement of the dominant shoulder (odds ratio = 2.02, 95% confidence interval = 1.16-3.52), and a higher body mass index (per 1 kg/m2: odds ratio = 1.06, 95% confidence interval = 1.03-1.12) were independently associated with rotator cuff tears. Sex, depression, smoking status, shoulder use at work, hypertension, and diabetes were not significantly associated with rotator cuff tear.

CONCLUSIONS

In a cohort of patients with shoulder pain, we identified older age, involvement of the dominant shoulder, and a higher body mass index to be independently associated with rotator cuff tear. The mechanism of how these factors possibly lead to rotator cuff tears needs further research.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME.

CME OBJECTIVES

Upon completion of this article, the reader should be able to: (1) Identify factors associated with an increased risk of developing rotator cuff tears in adults; (2) Describe the current epidemiological trends of rotator cuff tears in the United States; and (3) Discuss the pathophysiological role of aging in the development of nontraumatic rotator cuff tears.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Mid-Term Outcomes after Arthroscopic "Tear Completion Repair" of Partial Thickness Rotator Cuff Tears

Background and Objectives: Different arthroscopic procedures are used for partial-thickness rotator cuff tears (PT-RCTs), but there is still no evidence on the superiority of one procedure over the other. The aim of this study was to evaluate the clinical outcomes and the rate of complications of a tear completion repair (TCR) technique. Materials and Methods: Patients who had undergone arthroscopic TCR technique for PT-RCTs with a follow-up of at least 2-years after surgery were included. The TCR technique involved the removal of the "critical zone" and creating microfractures to biologically support tendon healing. Functional outcomes were assessed prospectively by the Constant score (CS) and active and passive range of movement (ROM). Pain and patient satisfaction were measured using a visual analog scale (VAS). Complication rates were recorded, and tendon integrity was assessed with magnetic resonance imaging (MRI) or ultrasound performed at least 2-years after surgery. Results: Eighty-seven patients with a median age of 57 years were followed-up for a median of 5 years. The CS score improved from 53.5 preoperatively to 94.0 postoperatively (p < 0.001). Median VAS score decreased from 8.6 to 1.0 (p < 0.0001). Median patient satisfaction was 9.3. The overall complication rate was 14.9%. Conclusions: Patients with PT-RCTs of the supraspinatus tendon treated by the TCR technique with "critical zone" removal and biological stimulation by microfractures showed good functional results with excellent strength recovery, a high degree of patient satisfaction, and resolution of painful symptoms at mid-term follow-up.

The shift in macrophages polarisation after tendon injury: A systematic review

Background

The role of macrophages (Mφs) in tendon injury healing is controversy. The aims of this study were to determine whether there is a shift in Mφs polarisation after an acute and chronic tendon injury ​and to assess whether the Mφs polarisation between the partial and complete rupture is different.

Methods

This systematic review of the scientific literature was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane guidelines. PubMed database and Excerpta Medica Database (EMBASE) were used for specific search criteria. Only studies measuring Mφs using specific cell markers in Achilles tendon tissue and rotator cuff tendon tissue were included, respectively.

Results

Five Achilles tendon injury studies and four rotator cuff injury studies were included. Expression of the pan Mϕs marker Cluster of Differentiation (CD) 68 was significantly upregulated in acute Achilles tendon ruptures compared to intact tendons, while no significant changes were found in Mφs polarisation markers CD80 (M1 Mφs) and CD206 (M2 Mφs). High levels of CD86 (M1 Mφs) and CD206 were observed in acute partial rupture. Expression of CD68 and CD206 were significantly upregulated in chronic rotator cuff tendinopathy and downregulated as structural failure increases. A low level of CD206 was observed in complete tendon rupture regardless of acute or chronic injury.

Discussion and conclusion

In spite of the limited number of articles included, findings from this study suggested that the process of inflammation plays an important role in acute Achilles tendon injuries, indicated by the increased expression of CD68+ Mφs. Low levels of CD206+ Mφs were constantly observed in complete Achilles tendon rupture, while high levels of CD80+ Mφs and CD206+ Mφs were observed in partial Achilles tendon rupture, which suggested the potential correlation between M2 Mφs and tendon structure. For chronic rotator cuff injury, CD68+ Mφs and CD206+ Mφs were higher in tendinopathic tissues in comparison to the intact control tissues. Both CD68+ Mφs and CD206+ Mφs has an inverse relation to the structural failure in the torn rotator cuff tendon. After tendon rupture, the time point of biopsy specimen collection is an important factor, which could occur in the acute phase or chronic phase. Collectively, the understanding of the roles in Mφs after tendon injury is inadequate, and more research efforts should be devoted to this direction.

The translational potential of this article

This article provided a potential implication on how pan Mφs or M2 Mφs might be associated with ruptured or torn tendon structure. Managing Mφs numbers and phenotypes may lead to possible novel therapeutic approaches to the management of early tendinopathy, early acute tendon rupture, hence, promote healing after restoration surgery.

Surgery for rotator cuff tears

BACKGROUND

This review is one in a series of Cochrane Reviews of interventions for shoulder disorders.

OBJECTIVES

To synthesise the available evidence regarding the benefits and harms of rotator cuff repair with or without subacromial decompression in the treatment of rotator cuff tears of the shoulder.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and WHO ICRTP registry unrestricted by date or language until 8 January 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including adults with full-thickness rotator cuff tears and assessing the effect of rotator cuff repair compared to placebo, no treatment, or any other treatment were included. As there were no trials comparing surgery with placebo, the primary comparison was rotator cuff repair with or without subacromial decompression versus non-operative treatment (exercises with or without glucocorticoid injection). Other comparisons were rotator cuff repair and acromioplasty versus rotator cuff repair alone, and rotator cuff repair and subacromial decompression versus subacromial decompression alone. Major outcomes were mean pain, shoulder function, quality of life, participant-rated global assessment of treatment success, adverse events and serious adverse events. The primary endpoint for this review was one year.

DATA COLLECTION AND ANALYSIS

We used standard methodologic procedures expected by Cochrane.

MAIN RESULTS

We included nine trials with 1007 participants. Three trials compared rotator cuff repair with subacromial decompression followed by exercises with exercise alone. These trials included 339 participants with full-thickness rotator cuff tears diagnosed with magnetic resonance imaging (MRI) or ultrasound examination. One of the three trials also provided up to three glucocorticoid injections in the exercise group. All surgery groups received tendon repair with subacromial decompression and the postoperative exercises were similar to the exercises provided for the non-operative groups. Five trials (526 participants) compared repair with acromioplasty versus repair alone; and one trial (142 participants) compared repair with subacromial decompression versus subacromial decompression alone. The mean age of trial participants ranged between 56 and 68 years, and females comprised 29% to 56% of the participants. Symptom duration varied from a mean of 10 months up to 28 months. Two trials excluded tears with traumatic onset of symptoms. One trial defined a minimum duration of symptoms of six months and required a trial of conservative therapy before inclusion. The trials included mainly repairable full-thickness supraspinatus tears, six trials specifically excluded tears involving the subscapularis tendon. All trials were at risk of bias for several criteria, most notably due to lack of participant and personnel blinding, but also for other reasons such as unclearly reported methods of random sequence generation or allocation concealment (six trials), incomplete outcome data (three trials), selective reporting (six trials), and other biases (six trials). Our main comparison was subacromial decompression versus non-operative treatment and results are reported for the 12 month follow up. At one year, moderate-certainty evidence (downgraded for bias) from 3 trials with 258 participants indicates that surgery probably provides little or no improvement in pain; mean pain (range 0 to 10, higher scores indicate more pain) was 1.6 points with non-operative treatment and 0.87 points better (0.43 better to 1.30 better) with surgery.. Mean function (zero to 100, higher score indicating better outcome) was 72 points with non-operative treatment and 6 points better (2.43 better to 9.54 better) with surgery (3 trials; 269 participants), low-certainty evidence (downgraded for bias and imprecision). Participant-rated global success rate was 873/1000 after non-operative treatment and 943/1000 after surgery corresponding to (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.96 to 1.22; low-certainty evidence (downgraded for bias and imprecision). Health-related quality of life was 57.5 points (SF-36 mental component score, 0 to 100, higher score indicating better quality of life) with non-operative treatment and 1.3 points worse (4.5 worse to 1.9 better) with surgery (1 trial; 103 participants), low-certainty evidence (downgraded for bias and imprecision). We were unable to estimate the risk of adverse events and serious adverse events as only one event was reported across the trials (very low-certainty evidence; downgraded once due to bias and twice due to very serious imprecision).

AUTHORS' CONCLUSIONS

At the moment, we are uncertain whether rotator cuff repair surgery provides clinically meaningful benefits to people with symptomatic tears; it may provide little or no clinically important benefits with respect to pain, function, overall quality of life or participant-rated global assessment of treatment success when compared with non-operative treatment. Surgery may not improve shoulder pain or function compared with exercises, with or without glucocorticoid injections. The trials included have methodology concerns and none included a placebo control. They included participants with mostly small degenerative tears involving the supraspinatus tendon and the conclusions of this review may not be applicable to traumatic tears, large tears involving the subscapularis tendon or young people. Furthermore, the trials did not assess if surgery could prevent arthritic changes in long-term follow-up. Further well-designed trials in this area that include a placebo-surgery control group and long follow-up are needed to further increase certainty about the effects of surgery for rotator cuff tears.

Augmenting endogenous repair of soft tissues with nanofibre scaffolds

As our ability to engineer nanoscale materials has developed we can now influence endogenous cellular processes with increasing precision. Consequently, the use of biomaterials to induce and guide the repair and regeneration of tissues is a rapidly developing area. This review focuses on soft tissue engineering, it will discuss the types of biomaterial scaffolds available before exploring physical, chemical and biological modifications to synthetic scaffolds. We will consider how these properties, in combination, can provide a precise design process, with the potential to meet the requirements of the injured and diseased soft tissue niche. Finally, we frame our discussions within clinical trial design and the regulatory framework, the consideration of which is fundamental to the successful translation of new biomaterials.

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.

KDR inferred haplotype is associated with upper limb dysfunction in breast cancer survivors of mixed ancestry

Introduction: Shoulder pain and disability are well-documented sequelae of breast cancer treatment. Angiogenesis signaling may have a role in the development of shoulder pain or shoulder disability in breast cancer survivors. The aim of this study was to determine if polymorphisms in angiogenesis-related genes are associated with shoulder pain or disability following breast cancer treatment.

Participants and methods: A cross-sectional study was conducted on 220 South African breast cancer survivors. The study aimed to evaluate associations between shoulder pain/disability and seven single nucleotide polymorphisms (SNPs) within five angiogenesis-associated genes: KDR (rs2305948 C>T; rs7667298 C>T), NOS3 (rs1549758 C>T), MMP2 (rs708269 A>T), THBS2 (rs9766678 A>G) and TIMP3 (rs5754312 T>A; rs715572 G>A). In addition, associations between shoulder pain/disability and inferred haplotypes for KDR and TIMP3 SNPs were evaluated. Participants were grouped into no–low and moderate–high shoulder pain/disability based on total pain/disability scores: ≤30 and >30, respectively using the shoulder pain and disability index (SPADI).

Results: No independent associations with shoulder pain/disability categories were found for all SNPs. However, 1 inferred haplotype (KDR “TT”) differed significantly (P=0.014) between the shoulder disability categories. After adjusting for participants’ age, the differences in KDR inferred haplotype frequencies between shoulder disability categories became non-significant (P=0.052).

Conclusion: Our findings provide a preliminary suggestion of a possible association between polymorphisms in genes involved in angiogenesis and the presence of moderate–high shoulder disability among South African breast cancer survivors. A larger prospective cohort study is currently being conducted by our group.

The Potential Roles of Tendon Stem/Progenitor Cells in Tendon Aging

Aging is a key dangerous factor for the occurrence and severity of tendon injury, but the exact cognition of the relationship is elusive at present. More previous studies suggest age-related changes occur at tendon mechanical properties, structure and composition, but the pathological alternations may be overlooked, which might be a cause for the structure and function variations, and even speed up the progress of age-related disorders. Recently, the presence of tendon stem/progenitor cells (TSPCs) would provide new insights for the pathogenesis of tendon aging. In this review, the tendon mechanical properties, structure and composition are presented in brief, then, the pathological changes of the aging tendon are described firstly, and the latest researches on alterations of TSPCs in the pathogenesis of tendon aging have also been analyzed. At a cellular level, the hypothetical model of altered TSPCs fate for tendon aging is also proposed. Moreover, the regulation of TSPCs as a potential way of the therapies for age-related tendon diseases is discussed. Therefore, reversing the impaired function of TSPCs and promoting the tenogenic differentiation of TSPCs could become hot spots for further study and give the opportunity to establish new treatment strategies for age-related tendon injuries.

The Arterial Anatomy of the Lateral Ligament Complex of the Ankle: A Cadaveric Study

BACKGROUND

Ankle sprains are the most common musculoskeletal injury in the United States. Chronic lateral ankle instability can ultimately require operative intervention to decrease pain and restore stability to the ankle joint. There are no anatomic studies investigating the vascular supply to the lateral ankle ligamentous complex.

PURPOSE

To define the vascular anatomy of the lateral ligament complex of the ankle.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Thirty pairs of cadaveric specimens (60 total legs) were amputated below the knee. India ink, followed by Ward blue latex, was injected into the peroneal, anterior tibial, and posterior tibial arteries to identify the vascular supply of the lateral ligaments of the ankle. Chemical debridement was performed with 8.0% sodium hypochlorite to remove the soft tissues, leaving casts of the vascular anatomy intact. The vascular supply to the lateral ligament complex was then evaluated and recorded.

RESULTS

The vascular supply to the lateral ankle ligaments was characterized in 56 specimens: 52 (92.9%) had arterial supply with an origin from the perforating anterior branch of the peroneal artery; 51 (91.1%), from the posterior branch of the peroneal artery; 29 (51.8%), from the lateral tarsal branch of the dorsalis pedis; and 12 (21.4%), from the posterior tibial artery. The anterior branch of the peroneal artery was the dominant vascular supply in 39 specimens (69.6%).

CONCLUSION

There are 4 separate sources of extraosseous blood supply to the lateral ligaments of the ankle. In all specimens, the anterior talofibular ligament was supplied by the anterior branch of the peroneal artery and/or the lateral tarsal artery of the dorsalis pedis, while the posterior talofibular ligament was supplied by the posterior branch of the peroneal artery and/or the posterior tibial artery. The calcaneofibular ligament received variable contributions from the anterior and posterior branches of the peroneal artery, with few specimens receiving a contribution from the lateral tarsal or posterior tibial arteries.

CLINICAL RELEVANCE

Understanding the vascular anatomy of the lateral ligament complex is beneficial when considering surgical management and may provide insight into factors that lead to chronic instability.

A Systematic Summary of Systematic Reviews on the Topic of the Rotator Cuff

BACKGROUND

The number of systematic reviews and meta-analyses published on the rotator cuff (RC) has increased markedly.

PURPOSE

To quantify the number of systematic reviews and meta-analyses published on the RC and to provide a qualitative summary of the literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic search for all systematic reviews and meta-analyses pertaining to the RC published between January 2007 and September 2017 was performed with PubMed, MEDLINE, and the Cochrane Database of Systematic Reviews. Narrative reviews and non-English language articles were excluded.

RESULTS

A total of 1078 articles were found, of which 196 met the inclusion criteria. Included articles were summarized and divided into 15 topics: anatomy and function, histology and genetics, diagnosis, epidemiology, athletes, nonoperative versus operative treatment, surgical repair methods, concomitant conditions and surgical procedures, RC tears after total shoulder arthroplasty, biological augmentation, postoperative rehabilitation, outcomes and complications, patient-reported outcome measures, cost-effectiveness of RC repair, and quality of randomized controlled trials.

CONCLUSION

A qualitative summary of the systematic reviews and meta-analyses published on the RC can provide surgeons with a single source of the most current literature.

Rehabilitation of symptomatic atraumatic degenerative rotator cuff tears: A clinical commentary on assessment and management

STUDY DESIGN

Clinical Commentary.

INTRODUCTION

Atraumatic rotator cuff (RC) disease, is one of the most common cause of shoulder pain, which encompasses a continuum from tendinopathy to full thickness cuff tears. Extrinsic, intrinsic and environmental factors have been implicated in the pathophysiology of this disorder, affecting the clinical presentation of symptoms including pain and irritability. Successful rehabilitation of symptomatic atraumatic degenerative rotator cuff (SADRC) tears must address the underlying mechanisms causing dysfunction and correct modifiable factors.

PURPOSE OF THE STUDY

The purpose of this paper is to review the shoulder complex anatomy, introduce atraumatic degenerative RC pathology, differentiate between symptomatic and asymptomatic degenerative RC tears, propose an assessment and introduce the Rotator Cuff Protocol 1 (RCP1) designed by the clinical reasoning of one of the lead authors (LW) as a rehabilitation management approach for those clients who present with SADRC tears.

METHODS/RESULTS/DISCUSSION

N/A for clinical commentary.

CONCLUSIONS

The ability to identify SADRC tears should consider shoulder anatomy, extrinsic, intrinsic and environmental factors, and the consideration for the natural history of atraumatic partial and full thickness tears in the general population. A thorough clinical history and examination, which includes shoulder symptom modification tests, allows the examiner to determine at what phase the patient may start their exercise program. The RCP1 is a program that has been used clinically by many therapists and clients over the years and research is underway to test this protocol in atraumatic rotator cuff disease including SADRC tears.

LEVEL OF EVIDENCE

5.

The potential role of angiogenesis in the development of shoulder pain, shoulder dysfunction, and lymphedema after breast cancer treatment

Shoulder morbidity is a well-documented sequela of breast cancer treatment, which includes various manifestations such as pain, reduced range of motion, and lymphedema, among others. The multifactorial nature of such morbidities has long been appreciated, and research on reliable risk predictors of development thereof still continues. Previous studies have demonstrated the potential of different types of physical therapy to treat such shoulder problems, and the integration of such interventions into routine care for breast cancer survivors is a requirement in most high-income countries. Although patients at risk for developing shoulder problems would most likely benefit from posttreatment physical therapy, currently, there is no gold standard for identifying this patient group. This is particularly important in low- and middle-income countries where scarce monetary resources need to be directed specifically to those most in need. Modulators of the angiogenesis pathway have been implicated in noncancer shoulder conditions such as rotator cuff disease, adhesive capsulitis, and tendon injuries. The present review summarizes the role of angiogenesis in the development of shoulder morbidity among breast cancer survivors and sets forth the rationale for our belief that angiogenesis signaling may help explain a proportion of the reported clinical variability noted in the development of shoulder pain and dysfunction and upper-limb lymphedema after breast cancer treatment.

Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders

Background

This study systematically summarizes quantitative imaging biomarker research in non-traumatic neck and shoulder musculoskeletal disorders (MSDs). There were two research questions: 1) Are there quantitative imaging biomarkers associated with the presence of neck and shoulder MSDs?, 2) Are there quantitative imaging biomarkers associated with the severity of neck and shoulder MSDs?

Methods

PubMed and SCOPUS were used for the literature search. One hundred and twenty-five studies met primary inclusion criteria. Data were extracted from 49 sufficient quality studies.

Results

Most of the 125 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. Only half controlled for potential confounders via exclusion or in the analysis. Approximately one-third reported response rates. In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied. The literature synthesis suggested that neck muscle size may be decreased in neck pain, and trapezius myalgia and neck/shoulder pain may be associated with reduced vascularity in the trapezius and reduced trapezius oxygen saturation at rest and in response to upper extremity tasks. Reduced vascularity in the supraspinatus tendon may also be a feature in rotator cuff tears. Five of eight studies showed an association between a quantitative imaging marker and MSD severity.

Conclusions

Although research on quantitative imaging biomarkers is still in a nascent stage, some MSD biomarkers were identified. There are limitations in the articles examined, including possible selection bias and inattention to potentially confounding factors. Recommendations for future studies are provided.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1694-y) contains supplementary material, which is available to authorized users.

Tendon vascularity in overhead athletes with subacromial pain syndrome and its correlation with the resting subacromial space

BACKGROUND

Supraspinatus tendinopathy is one of the common causes of subacromial pain syndrome (SAPS) in overhead athletes. Changes in tendon vascularity have been reported in painful tendons; however, the prevalence and distribution have not been investigated in young overhead athletes.

METHODS

We conducted a cross-sectional study of 47 overhead athletes (male, 31; female, 16) aged 18 to 36 years with SAPS for >3 months. A sonographer graded the severity of the tendinopathy and area of vascularization. Ultrasound imaging was used to measure supraspinatus tendon thickness, vascularity, and resting subacromial space. A self-written program was used to semiquantify the intensity of vascularity, expressed as the vascular index.

RESULTS

The majority (87.2%) of the participants had signs of tendinopathy in the supraspinatus tendon, and 40 (85.1%) of the tendinopathic tendons had vascularity. The majority (66.0%) of the vascularized subjects presented with minimal increase in vascularity, and 19.1% had moderate to severe vascularization. Most (79.2%) of the vascularization was observed in the pericortical region. The vascular index was negatively correlated with the resting subacromial space in male athletes with a reduced subacromial space (ρ = -0.63; P = .038).

CONCLUSION

Of overhead athletes with SAPS, 87.2% had supraspinatus tendinopathy with minimal to moderate vascularization, with the majority of vascularization occurring in the pericortical region. In male athletes with a reduced subacromial space, greater vascularity in the supraspinatus tendon was associated with a smaller resting subacromial space.

Microvascular blood flow in normal and pathologic rotator cuffs

BACKGROUND

Microvascular blood flow in the tendon plays an important role in the pathogenesis of rotator cuff abnormalities. There are conflicting views about the presence of a hypovascular zone in the supraspinatus tendon. Besides, no studies have looked at the pattern of blood flow around a partial-thickness tear. Our aim was to measure microvascular blood flow in normal and a range of pathologic rotator cuff tendons using laser doppler flowmetry.

METHODS

A total of 120 patients having arthroscopic shoulder surgery were divided into 4 equal groups on the basis of their intraoperative diagnosis: normal rotator cuff, subacromial impingement syndrome, and partial-thickness or full-thickness rotator cuff tear. Microvascular blood flow was measured at 5 different regions of each cuff using a laser doppler probe. The values were compared to assess variability within and between individuals.

RESULTS

Total blood flow was greater in the normal rotator cuff group compared with the groups with pathologic rotator cuffs, with the largest difference seen in the subacromial impingement group. Within individuals, blood flow was highest at the musculotendinous junction and lowest at the lateral insertional part of the tendon. Among groups, the blood flow was significantly lower at the anteromedial and posteromedial cuff in the groups with impingement and full-thickness tears compared with the group with normal cuff.

CONCLUSION

Real-time in vivo laser doppler analysis has shown that microvascular blood flow is not uniform throughout the supraspinatus tendon. Blood flow in the pathologic supraspinatus tendon was significantly lower compared with the normal tendon.

Rotator Cuff Tendinopathy: Navigating the Diagnosis-Management Conundrum

Synopsis The hallmark characteristics of rotator cuff (RC) tendinopathy are pain and weakness, experienced most commonly during shoulder external rotation and elevation. Assessment is complicated by nonspecific clinical tests and the poor correlation between structural failure and symptoms. As such, diagnosis is best reached by exclusion of other potential sources of symptoms. Symptomatic incidence and prevalence data currently cannot be determined with confidence, primarily as a consequence of a lack of diagnostic accuracy, as well as the uncertainty as to the location of symptoms. People with symptoms of RC tendinopathy should derive considerable comfort from research that consistently demonstrates improvement in symptoms with a well-structured and graduated exercise program. This improvement is equivalent to outcomes reported in surgical trials, with the additional generalized benefits of exercise, less sick leave, a faster return to work, and reduced costs to the health care system. This evidence covers the spectrum of conditions that include symptomatic RC tendinopathy and atraumatic partial- and full-thickness RC tears. The principles guiding exercise treatment for RC tendinopathy include relative rest, modification of painful activities, an exercise strategy that initially does not exacerbate pain, controlled reloading, and gradual progression from simple to complex shoulder movements. Evidence also exists for a specific exercise program being beneficial for people with massive inoperable tears of the RC. Education is an essential component of rehabilitation, and attention to lifestyle factors (smoking cessation, nutrition, stress, and sleep management) may enhance outcomes. Outcomes may also be enhanced by subgrouping RC tendinopathy presentations and directing treatment strategies according to the clinical presentation and the patient's response to shoulder symptom modification procedures outlined herein. There are substantial deficits in our knowledge regarding RC tendinopathy that need to be addressed to further improve clinical outcomes. J Orthop Sports Phys Ther 2015;45(11):923-937. Epub 21 Sep 2015. doi:10.2519/jospt.2015.5941.

Not All Tendons Are Created Equal: Implications for Differing Treatment Approaches

The majority of muscles have distinct tendinous attachments to bones; however, only a few tendons develop painful conditions. That simple observation prompts us to ask a few questions. Are there commonalities in morphology and pathology among the painful tendons? What contributes to the propensity for pathology in some, but not all, tendons? And, consequently, should all tendinopathies be managed equally? Two common tendinopathies are those affecting the Achilles and supraspinatus, which are presented in this special issue and serve as excellent models to discuss similarities and contrasts. J Orthop Sports Phys Ther 2015;45(11):829-832. doi:10.2519/jospt.2015.0114.

The risks and benefits of glucocorticoid treatment for tendinopathy: a systematic review of the effects of local glucocorticoid on tendon

OBJECTIVE

Our primary objective was to summarise the known effects of locally administered glucocorticoid on tendon tissue and tendon cells.

METHODS

We conducted a systematic review of the scientific literature using the PRISMA and Cochrane guidelines of the Medline database using specific search criteria. The search yielded 50 articles, which consisted of 13 human studies, 36 animal studies and one combined human/animal study.

RESULTS

Histologically, there was a loss of collagen organisation (6 studies) and an increase in collagen necrosis (3 studies). The proliferation (8 studies) and viability (9 studies) of fibroblasts was reduced. Collagen synthesis was decreased in 17 studies. An increased inflammatory cell infiltrate was shown in 4 studies. Increased cellular toxicity was demonstrated by 3 studies. The mechanical properties of tendon were investigated by 18 studies. Descriptively, 6 of these studies showed a decrease in mechanical properties, 3 showed an increase, while the remaining 9 showed no significant change. A meta-analysis of the mechanical data revealed a significant deterioration in mechanical properties, with an overall effect size of -0.67 (95% CI = 0.01 to -1.33) (data from 9 studies).

CONCLUSIONS

Overall it is clear that the local administration of glucocorticoid has significant negative effects on tendon cells in vitro, including reduced cell viability, cell proliferation and collagen synthesis. There is increased collagen disorganisation and necrosis as shown by in vivo studies. The mechanical properties of tendon are also significantly reduced. This review supports the emerging clinical evidence that shows significant long-term harms to tendon tissue and cells associated with glucocorticoid injections.

The peripheral neuronal phenotype is important in the pathogenesis of painful human tendinopathy: a systematic review

BACKGROUND

The pathogenesis of tendinopathy is complex and incompletely understood. Although significant advances have been made in terms of understanding the pathological changes in both the extracellular matrix and the cells involved, relatively little is known about the role of neuronal regulation in tendinopathy. The frequent mismatch between tendon pathology and pain may be explained, in part, by differences in the peripheral neuronal phenotype of patients.

QUESTIONS/PURPOSES

The primary purpose of this review was to determine whether evidence exists of changes in the peripheral neuronal phenotype in painful human tendinopathy and, if so, to identify the associated histological and molecular changes. The secondary purpose was to determine if any changes in the peripheral neuronal phenotype reported correlate with pain symptoms.

METHODS

We conducted a systematic review of the scientific literature using the PRISMA and Cochrane guidelines. The Medline and Embase databases were searched using specific search criteria. Only studies analyzing the peripheral tissue of patients with the clinical diagnosis of tendinopathy were included. Inclusion was agreed on by two independent researchers on review of abstracts or full text.

RESULTS

Overall in the 27 included studies, there was clear evidence of changes in the peripheral neuronal phenotype in painful human tendinopathy. The excitatory glutaminergic system was significantly upregulated in seven studies, there was a significant increase in sensory neuropeptide expression in four studies, and there were significant changes in the molecular morphology of tenocytes, blood vessels, and nerves. In rotator cuff tendinopathy, substance P has been shown to correlate with pain and the neural density in the subacromial bursa has been shown to correlate with rest pain.

CONCLUSIONS

The peripheral neuronal phenotype is an important factor in the pathogenesis of painful human tendinopathy. Further research in this area specifically correlating tissue changes to clinical scores has great potential in further developing our understanding of the disease process.

Rotator cuff: biology and current arthroscopic techniques

The present article summarizes current trends in arthroscopic rotator cuff repairs focusing on the used repair technique, potential influencing factors on the results, and long-term outcome after reconstruction of the rotator cuff. Moreover, different treatment options for the treatment for irreparable rotator cuff ruptures were described, and the results of additional augmentation of the repairs with platelet-rich plasma were critically analyzed. Based on the current literature, double-row repairs did not achieve superior clinical results compared to single-row repairs neither in the clinical results nor in the re-rupture rate. Multiple factors such as age, fatty infiltration, and initial rupture size might influence the results. If the rupture is not repairable, various options were described including cuff debridement, partial repair, tuberoplasty, or tendon transfers. The additional augmentation with platelet-rich plasma did not reveal any significant differences in the healing rate compared to conventional rotator cuff repairs.

LEVEL OF EVIDENCE

IV.

Current imaging of the rotator cuff

Rotator cuff pathology is a common cause of shoulder pain, and imaging plays a major role in the management of shoulder problems. General radiography may be useful as an initial screening test particularly in trauma and arthritis. Musculoskeletal ultrasound and magnetic resonance imaging are the most suitable modalities for the investigation of the rotator cuff, having high sensitivities and specificities for full-thickness tears. Musculoskeletal ultrasound and magnetic resonance imaging are less accurate in the detection of partial-thickness tears with greater observer variability. This article reviews the normal and pathologic imaging features of the rotator cuff and highlights the potential usefulness and limitations of various imaging modalities in the assessment of the tendon and the potential impact of imaging findings on clinical patient care.

Contrast-enhanced sonographic characterization of the vascularity of the repaired rotator cuff: utility of maximum intensity projection imaging

OBJECTIVES

To characterize the distribution of vascularity of the postoperative rotator cuff tendon using a maximum intensity projection technique after contrast-enhanced sonography.

METHODS

We retrospectively evaluated image data on 23 patients (11 male and 12 female) with intact rotator cuff repairs who had previously undergone contrast-enhanced sonography of their shoulders using lipid microspheres before and after a standardized exercise protocol. The patients were on average 3 months out from their surgery. Using offline image analysis software, a maximum intensity projection image was obtained for each patient, reflecting the regional vascular distribution within the repair and adjacent soft tissue. Subjective analysis was performed in 4 regions of interest: peribursal, articular medial, articular lateral, and suture anchor, independently by 2 musculoskeletal radiologists using a semiquantitative scale ranging from 0 to 4 for each region (0, no enhancement; 1, 1%-25% enhancement; 2, 26%-50%; 3, 51%-75%; and 4, 76%-100%). A combined vascularity score (0-8) was produced for each region and formed the basis for the subjective analysis.

RESULTS

Using a Mann-Whitney nonparametric test, the data showed significantly higher regional enhancement in the peribursal and suture anchor regions compared to the tendon (P < .001). Exercise resulted in a statistically significant increase in the extent of enhancement in all regions (P < .002). Inter-rater reliability analysis using a weighted κ statistic showed strong agreement (0.63-0.64) for the suture anchor site and moderate agreement for the others (peribursal, 0.35-0.39; articular medial, 0.45-0.55; and articular lateral 0.32-0.33).

CONCLUSIONS

The maximum intensity projection technique after contrast-enhanced sonography provides a topographic map of rotator cuff vascularity; the latter has been implicated as an important factor in promoting bone-tendon healing. Approximately 3 months after rotator cuff repair, the suture anchor and peribursal regions showed the most robust vascularity. Maximum intensity projection imaging further establishes that there is a global increase in vascular response at the repair site after exercise.

Effect of angiogenesis-related cytokines on rotator cuff disease: the search for sensitive biomarkers of early tendon degeneration

BACKGROUND

Hallmarks of the pathogenesis of rotator cuff disease (RCD) include an abnormal immune response, angiogenesis, and altered variables of vascularity. Degenerative changes enhance production of pro-inflammatory, anti-inflammatory, and vascular angiogenesis-related cytokines (ARC) that play a pivotal role in the immune response to arthroscopic surgery and participate in the pathogenesis of RCD. The purpose of this study was to evaluate the ARC profile, ie, interleukin (IL): IL-1β, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and angiogenin (ANG), in human peripheral blood serum and correlate this with early degenerative changes in patients with RCD.

METHODS

Blood specimens were obtained from 200 patients with RCD and 200 patients seen in the orthopedic clinic for nonrotator cuff disorders. Angiogenesis imaging assays was performed using power Doppler ultrasound to evaluate variables of vascularity in the rotator cuff tendons. Expression of ARC was measured by commercial Bio-Plex Precision Pro Human Cytokine Assays.

RESULTS

Baseline concentrations of IL-1β, IL-8, and VEGF was significantly higher in RCD patients than in controls. Significantly higher serum VEGF levels were found in 85% of patients with RCD, and correlated with advanced stage of disease (r = 0.75; P < 0.0005), average microvascular density (r = 0.68, P < 0.005), and visual analog score (r = 0.75, P < 0.0002) in RCD patients. ANG and IL-10 levels were significantly lower in RCD patients versus controls. IL-1β and ANG levels were significantly correlated with degenerative tendon grade in RCD patients. No difference in IL-6 and bFGF levels was observed between RCD patients and controls. Patients with degenerative changes had markedly lower ANG levels compared with controls. Power Doppler ultrasound showed high blood vessel density in patients with tendon rupture.

CONCLUSION

The pathogenesis of RCD is associated with an imbalance between pro-inflammatory, anti-inflammatory, and vascular ARC.

Metrenperone enhances collagen turnover and remodeling in the early stages of healing of tendon injury in rabbit

INTRODUCTION

This study evaluated the effects of metrenperone on healing of unilateral, collagenase-induced lesions in the Superficial Digital Flexor Tendons (SDFT) of rabbits.

METHODS

After controlled injury of the left SDFT, nine rabbits received daily treatment with metrenperone for 28 days. Another nine were untreated controls; in both groups the contra-lateral tendons served as uninjured controls. Histological and ultrastructural changes, mechanical properties, dry weight, collagen content, and amount of DNA in healing and control tendons were assessed 28 days after injury.

RESULTS

Restoration of structural hierarchy was more organized in treated than in untreated tendons while cellularity was greater in the latter. At the ultrastructural level, collagen in treated lesions was predominantly in the form of small-diameter, new fibrils, with few large, old fibrils; in untreated lesions there was a high proportion of large, old fibrils but relatively few small, new ones. The amount of DNA in untreated injuries was much greater than in normal tendons, while in treated lesions it was not significantly different from that of uninjured controls. There were no significant differences in total collagen, stiffness and ultimate strength of injured, treated, and untreated tendons 28 days after injury. Both were significantly weaker than their corresponding contralaterals.

CONCLUSIONS

The findings suggest that metrenperone had positive effects on collagen turnover, remodelling, and organization during acute inflammation and fibroplasia. Provided that the new fibrils subsequently matured in a normal manner, mechanical characteristics of the organized scar should be better than those of an untreated lesion.

Effects of one-month continuous passive motion after arthroscopic rotator cuff repair: results at 1-year follow-up of a prospective randomized study

The study included 100 patients who underwent an arthroscopic rotator cuff repair. All patients suffered about a rotator cuff tear that was repaired arthroscopically with a suture anchor technique. Immediately postoperatively, patients were randomly allocated to one of two different postoperative physiotherapy regimens: passive self-assisted range of motion exercise (controls: 46 patients) versus passive self-assisted range of motion exercise associated with use of continuous passive motion (CPM) for a total of 2 h per day (experimental group: 54 patients), for 4 weeks. After this time, all the patients of both groups underwent the same physical therapy protocol. An independent examiner assessed the patients at 2.5, 6 and 12 months particularly about pain with the VAS scale (0-10) and the range of motion (ROM). Our findings show that postoperative treatment of an arthroscopic rotator cuff repair with passive self-assisted exercises associated with 2-h CPM a day provides a significant advantage in terms of ROM improvement and pain relief when compared to passive self-assisted exercise alone, at the short-term follow-up. No significant differences between the two groups were observed at 1 year postoperatively.