The biomechanical and histological effects of diabetes on tendon healing: experimental study in rats

Perioperative glycemic control reduces the risk of retear in diabetic patients following arthroscopic rotator cuff repair: A meta-analysis

BACKGROUND

Previous studies have associated diabetes with reduced shoulder motion, increased pain, and higher postoperative retear risk after arthroscopic rotator cuff repair (ARCR). However, the impact of glycemic control, measured by hemoglobin A1c (HbA1c) levels, on retear and revision rates after ARCR in diabetic patients remains unclear.

METHODS

This systematic review was conducted using the PubMed, Cochrane Library, Web of Science, and Embase databases according to the preferred reporting conventions for systematic reviews and meta-analyses. Only studies that compared retears and revisions in ARCR patients with documented HbA1c levels between controlled and uncontrolled diabetes groups were included. Relevant data were extracted and analyzed using STATA software. The methodological index for nonrandomized studies was employed to assess the risk of bias in the selected studies. Additionally, heterogeneity tests and sensitivity analyses were conducted to evaluate potential heterogeneity within the samples, and publication bias was also detected.

RESULTS

Six studies (4395 patients), including five retrospective cohort studies and one case‒control study, were included. Four of these studies assessed retears involving 253 patients. Lower HbA1c levels, indicating better glycemic control, were significantly associated with reduced retear rates after ARCR in diabetic patients (P = 0.000; odds ratio = 0.242, 95 % confidence interval: 0.128-0.454; I2 = 25 %). For revision evaluations, two studies, with a total of 4142 patients, found no significant difference in rates between controlled and uncontrolled diabetes groups, and no publication bias was detected.

CONCLUSION

Following ARCR in diabetic patients, effective glycemic control significantly reduces retear rates without affecting revisions, and maintaining glycemic control in the postoperative period may contribute to rotator cuff healing.

Postoperative HbA1c Level as a Predictor of Rotator Cuff Integrity After Arthroscopic Rotator Cuff Repair in Patients With Type 2 Diabetes

Background

In patients with type 2 diabetes mellitus (DM), preoperative glycosylated hemoglobin (HbA1c) is associated with outcomes after arthroscopic rotator cuff repair (ARCR); however, the relationship between outcomes and postoperative serum glycosylated hemoglobin (HbA1c) after ARCR has not been investigated.

Purpose

To evaluate outcomes after ARCR in patients (1) with and without DM and (2) with DM according to their pre- and postoperative HbA1c levels.

Study Design

Cohort study; Level of evidence, 3.

Method

Included in this study were 148 patients without DM and 35 patients with type 2 DM who underwent ARCR between January 1, 2017, and December 31, 2019. Clinical and radiological outcomes were evaluated preoperatively and at the latest clinical follow-up. Postoperative magnetic resonance imaging was performed after 12 months. In patients with type 2 DM, HbA1c levels were evaluated preoperatively as well as 6 and 12 months postoperatively; patients with an HbA1c level of ≥7% were defined as having uncontrolled DM. Multivariate logistic regression analyses were performed to determine the factors for retears after ARCR.

Results

The retear rates after ARCR were 22.9% (8/35) and 16.9% (25/148) in patients with and without DM, respectively. The retear rates were significantly higher in the 6-month postoperative uncontrolled DM group than in the controlled DM and non-DM groups (50% vs 8.7% and 16.8%; P < .05). The odds ratio for retears in the postoperative uncontrolled DM group was 5.555 (P =0.01) compared with the non-DM group. Among the patients with DM, in the uncontrolled DM group, 6-month postoperative hyperglycemia was superior in accuracy, sensitivity, and specificity for predicting retears after ARCR than preoperative hyperglycemia (77.1% vs 62.9%, 75% vs 37.5%, and 77.8% vs 70.4%, respectively).

Conclusion

This study demonstrated the association between uncontrolled postoperative DM and an increased risk of retears compared with no DM or controlled DM. Furthermore, postoperative HbA1c values were correlated more closely with the risk of retears than preoperative HbA1c values.

Diabetes Mellitus and Obesity as Prognostic Factors in Arthroscopic Repair of Chronic Rotator Cuff Tears

Metabolic diseases such as obesity and diabetes mellitus seem to have an influence on reoperation and long-term functional outcomes after arthroscopic repair of chronic rotator cuff tears. High prevalence of these pathologies can be found in the Canary Islands. A retrospective cohort study was carried out, in which 80 patients undergoing shoulder arthroscopic surgery for the repair of chronic rotator cuff tears were included, with a minimum follow up of 5 years, to study the occurrence of complications, reoperation, and functional outcomes. Functionality after surgery improved in 75% of patients with diabetes and remained the same or worsened in 25% (OR = 1.444). In the group of non-diabetic patients, 83.9% had improved function after surgery while it remained the same or worsened in 16.1% (OR = 0.830). Functionality after surgery improved in 76.6% of obese patients and remained the same or worsened in 23.4% (OR = 1.324). In the non-obese group, 87.9% had improved function after surgery, while it remained the same or worsened in 12.1% (OR = 0.598). Despite not obtaining statistically significant differences, the analysis of the results obtained suggests that obesity and diabetes could act by decreasing the subjective improvement in functionality after surgery, and, in the case of obesity, also increase the risk of reoperation.

Patients with diabetes mellitus experience poorer outcomes after arthroscopic rotator cuff repair

Hypothesis

The purpose of this study was to identify potential differences using validated clinical outcome instruments between patients with and without diabetes mellitus (DM) after arthroscopic rotator cuff repair (RCR).

Methods

Six-hundred eighty-four patients (32 with and 652 without DM) who underwent arthroscopic RCR were prospectively followed using the visual analog pain scale, Simple Shoulder Test, Single Assessment Numeric Evaluation, American Shoulder and Elbow Surgeons score, and Veterans RAND 12-item Health Survey (mental and physical component scores) preoperatively and at 3, 6, 12, and 24 months postoperatively.

Results

Patients with DM experienced significantly more pain (P = .0172) and had lower Simple Shoulder Test (P = .0458) and American Shoulder and Elbow Surgeons (P = .0200) scores than patients without DM 6 months after surgery. Although differences between groups are seen at other postoperative time points, none are statistically significant.

They also exhibited lower self-rated mental health status at 12 months (P = .0034) and 24 months (P = .0077), as well as lower self-rated physical health status at 12 months (P = .0223) and 24 months (P = .0077). Changes in scores from preoperatively to postoperatively were not different for patients with DM vs. without DM.

Conclusion

Patients with DM experience significantly more pain, exhibit significantly poorer shoulder function, and report persistently diminished mental and physical health status compared with their counterparts without DM after undergoing arthroscopic RCR. Although these differences did not reach the minimal clinically important difference, orthopedic surgeons should be cognizant of DM as an outcome-modifying variable when selecting, counseling, and treating patients with rotator cuff tears. Glycemic control should be scrutinized and optimized during the perioperative medical evaluation and ultimately factored into the surgical risk profile and prognosis.

Diabetes and treatment with orally administrated corticosteroids negatively affect treatment outcome at follow-up after acute Achilles tendon rupture

PURPOSE

Studies investigating the influence of comorbidities on patient-reported outcomes after acute Achilles tendon ruptures (ATR) are lacking. In this study, the aim was to investigate the effect of comorbidity and medical treatment on the patient-reported outcome measure Achilles tendon total rupture score (ATRS).

METHODS

The study was performed as a registry study from the Danish Achilles tendon Database (DADB). In the DADB, ATRS was registered at baseline (prior to rupture), at 3-6 month, 1-year and 2-year follow-ups. The outcomes were ATRS at follow-up and the change in ATRS from baseline to follow-up. Variables of interest were diabetes, hypertension, rheumatic disease and treatment with orally administrated corticosteroids. Linear mixed-effects models including all follow-up time points in the same model were used adjusting for sex, age group, treatment (operative or non-operative) and the investigated comorbidities.

RESULTS

Data were collected from 2012 to 2019. Two thousand and four patients with ATR were included. Patients with the investigated comorbidities and treatment with orally administrated corticosteroid scored 10.6-19.1 points lower in mean ATRS at baseline (prior to rupture) compared to patients without the respective disease or treatment. At follow-up, patients with diabetes (mean difference, [95% CI]) (- 6.2, [- 11.7; - 0.8]; P = 0.03) and patients in treatment with orally administrated corticosteroids (- 10.9, [- 16.2; - 5.7]; P < 0.01) had a statistically significantly worse ATRS than patients without the respective disease. However, change in ATRS from baseline to follow-up was not affected. Hypertension and rheumatic disease did not affect ATRS at follow-up but had a positive effect on change in ATRS (4.3, [0.5; 8.1]; P = 0.03) and (12.0, [5.0; 19.9]; P < 0.01), respectively. No other statistically significant differences were found.

CONCLUSION

This study showed that patients with diabetes, hypertension, rheumatic disease and patients in treatment with orally administrated corticosteroids had a lower ATRS at baseline (prior to the rupture) when compared to patients without the respective disease or treatment. Diabetes and treatment with orally administrated corticosteroids did negatively affect ATRS at follow-up, but none of the investigated comorbidities or treatment with orally administrated corticosteroids did negatively affect change in ATRS from baseline to follow-up.

LEVEL OF EVIDENCE

Level III.

Metabolic Regulation of Tendon Inflammation and Healing Following Injury

PURPOSE OF REVIEW

This review seeks to provide an overview of the role of inflammation and metabolism in tendon cell function, tendinopathy, and tendon healing. We have summarized the state of knowledge in both tendon and enthesis.

RECENT FINDINGS

Recent advances in the field include a substantial improvement in our understanding of tendon cell biology, including the heterogeneity of the tenocyte environment during homeostasis, the diversity of the cellular milieu during in vivo tendon healing, and the effects of inflammation and altered metabolism on tendon cell function in vitro. In addition, the mechanisms by which altered systemic metabolism, such as diabetes, disrupts tendon homeostasis continue to be better understood. A central conclusion of this review is the critical need to better define fundamental cellular and signaling mechanisms of inflammation and metabolism during tendon homeostasis, tendinopathy, and tendon healing in order to identify therapies to enhance or maintain tendon function.

Comparison of the Effects of Pulsed Electromagnetic Field and Extracorporeal Shockwave Therapy in a Rabbit Model of Experimentally Induced Achilles Tendon Injury

Achilles tendon injuries are a common cause of complications including adhesions and tendon degeneration. As a result of these complications, the biomechanical properties are lost. Extracorporeal shockwave therapy (ESWT) and pulsed electromagnetic field (PEMF) recover the injured tendon structure; however, detailed studies of changes in tendon biomechanical properties are limited. We hypothesized that PEMF application would improve Achilles tendon biomechanical properties similar to ESWT. The curative effects of a PEMF 4-week application (15 Hz, 1 mT, 260 µs, 1 h/day) and ESWT (3 doses/28 days, 1st dose: 0.12 mJ/mm2 , 15 Hz, 300 impulses; 2nd dose: 0.14 mJ/mm2 , 15 Hz, 500 impulses; 3rd dose: 0.14 mJ/mm2 , 15 Hz, 500 impulses) on rabbits with Achilles tendon injury were investigated in terms of histopathological and biomechanical properties. The clinical feasibility of PEMF application was evaluated by comparing the results of both methods. Fifty New Zealand female rabbits were divided into two groups to be used in either biomechanical or immunohistochemical studies. Each of the two groups was further divided into five groups: C (Control), SH (Sham), TI (tendon injury), TI + ESWT, and TI + PEMF. Biomechanical evaluations revealed that maximum load, toughness, and maximum stress averages of the TI + PEMF group significantly increased (P < 0.05). When immunohistochemical images of the TI + PEMF group were compared with those of the TI group, the amount of fibrous tissue was less, the homogeneity of collagen fibers recovered, and collagen organization was more uniform. We conclude that both ESWT and PEMF are equally efficient for Achilles tendon recovery. PEMF application is effective and can be used in the clinic as a painless alternative treatment method. © 2020 Bioelectromagnetics Society.

Understanding cellular and molecular mechanisms of pathogenesis of diabetic tendinopathy

There is accumulating evidence of an increased incidence of tendon disorders in people with diabetes mellitus. Diabetic tendinopathy is an important cause of chronic pain, restricted activity, and even tendon rupture in individuals. Tenocytes and tendon stem/progenitor cells (TSPCs) are the dominant cellular components associated with tendon homeostasis, maintenance, remodeling, and repair. Some previous studies have shown alterations in tenocytes and TSPCs in high glucose or diabetic conditions that might cause structural and functional variations in diabetic tendons and even accelerate the development and progression of diabetic tendinopathy. In this review, the biomechanical properties and histopathological changes in diabetic tendons are described. Then, the cellular and molecular alterations in both tenocytes and TSPCs are summarized, and the underlying mechanisms involved are also analyzed. A better understanding of the underlying cellular and molecular pathogenesis of diabetic tendinopathy would provide new insight for the exploration and development of effective therapeutics.

Patients With Diabetes Mellitus Have a Higher Risk of Tendon Retear After Arthroscopic Rotator Cuff Repair: A Meta-analysis

Background

Retear of a repaired rotator cuff tendon is a major issue for shoulder surgeons. It is possible that diabetes mellitus (DM) is associated with a greater risk of tendon retear after arthroscopic rotator cuff repair.

Purpose

To determine whether patients with DM have a higher tendon retear risk after arthroscopic rotator cuff repair.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the Web of Science, PubMed, and Embase databases. Inclusion criteria were articles written in the English language that included patients undergoing arthroscopic rotator cuff repair surgeries, reported the numbers of patients with and those without DM, and reported the number of rotator cuff retears. Data relevant to this study were extracted and statistically analyzed. Random-effects models were used to generate pooled odds ratio estimates and CIs.

Results

A total of 160 studies were identified from the initial search, and 5 of them met the inclusion criteria. A total of 1065 patients (207 patients with DM and 858 patients without DM) were included. The pooled results showed that the patients in the DM group had a significantly higher tendon retear risk than did those in the non-DM group (relative risk, 2.25; 95% CI, 1.14-4.45; P = .02).

Conclusion

Patients with DM have a 2.25 times higher risk of tendon retear after arthroscopic rotator cuff repair compared with patients without DM.

Diabetic patients are almost twice as likely to experience complications from arthroscopic rotator cuff repair

AIMS

Large population-based studies have demonstrated increased prevalence of rotator cuff disease amongst diabetics. Recent studies have suggested comparable clinical outcomes from rotator cuff repair despite suggestions of increased complication rates amongst diabetics. However, there is a relative paucity of studies considering the effect of diabetes upon complication rate. We aim to report and quantify the effect of diabetes on complication rates following arthroscopic rotator cuff repair.

MATERIALS AND METHODS

A retrospective review of a consecutive series of patients undergoing arthroscopic rotator cuff repair between January 2011 and December 2014 was performed. Diabetic status and complication data defined as infection, frozen shoulder, re-tear or re-operation were collected and interrogated.

RESULTS

A total of 462 patients were included at median follow-up of 5.6 years. Diabetics were significantly more likely to experience frozen shoulder (15.8% vs. 4.4%, p = 0.001), re-tear (26.3% vs. 15.6%, p = 0.042) or at least one complication following surgery (35.1% vs. 22.7%, p = 0.041) compared to non-diabetics. These equated to odds ratios of 4.03, 1.94 and 1.84, respectively.

CONCLUSIONS

Diabetic patients are almost twice as likely to experience complications following arthroscopic rotator cuff repair, including double the risk of repair failure and more than four times the risk of frozen shoulder.

Effect of photobiomodulation and exercise on early remodeling of the Achilles tendon in streptozotocin-induced diabetic rats

The aim of this study was to compare the treatment effects of laser photobiomodulation (LPBM) therapy and aerobic exercise on the biomechanical properties, tissue morphology and the expression of tendon matrix molecules during early remodeling of Achilles tendon (AT) injury in diabetic rats. Animals were randomly assigned to five groups: injured non diabetic (I, n = 15), injured diabetic (ID, n = 15), injured diabetic plus LPBM (IDL, n = 16), injured diabetic plus aerobic exercise (IDE, n = 16) and injured diabetic plus aerobic exercise and LPBM (IDEAL, n = 17). Type 1 diabetes was induced via a single intravenous injection of Streptozotocin at a dose of 40 mg/kg. A partial tenotomy was performed in the right AT. LPBM was performed with an indium-gallium-aluminum-phosphide 660 nm 10 mW laser device (spot size 0.04 cm2, power density 250 mW/cm2, irradiation duration 16 s, energy 0.16 J, energy density 4 J/cm2) on alternate days for a total of 9 sessions over 3 weeks (total energy 1.44 J), using a stationary contact technique to a single point over the dorsal aspect of the AT. Moderate aerobic exercise was performed on a motorized treadmill (velocity 9 m/min for 60 minutes). At 3 weeks post-injury, biomechanical analyzes as well as assessment of fibroblast number and orientation were performed. Collagen 1 (Col1) and 3 (Col3) and matrix metalloproteinases (MMPs) -3 and 13 protein distributions were studied by immunohistochemistry; while Col1 and Col3 and MMP-2 and 9 gene expression were assessed by quantitative RT-PCR (qRT-PCR). IDEAL exhibited significant increases in several biomechanical parameters in comparison to the other groups. Moreover, IDEAL presented stronger Col1 immunoreactivity when compared to ID, and weaker Col3 immunoreactivity than IDE. Both IDL and IDEAL demonstrated weaker expression of MMP-3 in comparison to I, while IDL presented no expression of MMP-13 when compared to ID. ID, IDL and IDE showed an increased number of fibroblasts in comparison to I, while IDEAL decreased the number of these cells in comparison to ID and IDE. IDL and IDEAL groups exhibited decreased angular dispersion among the fibroblasts when compared to I. The gene expression results showed that IDE demonstrated a downregulation in Col1 mRNA expression in comparison to I and ID. IDEAL demonstrated upregulation of Col1 mRNA expression when compared to IDL or IDE alone and increased MMP-2 expression when compared to IDL and IDE. MMP-9 expression was upregulated in IDEAL when compared to I, IDL and IDE. Our results suggest a beneficial interaction of combining both treatment strategies i.e., aerobic exercise and LPBM, on the biomechanical properties, tissue morphology and the expression of matrix molecules in diabetic tendons.

Therapeutic management of closed central slip injuries: Outcome of a service evaluation

Introduction

Closed central slip injuries can be difficult to manage and there is a lack of published research to support evidence-based clinical decision making in practice. This article presents the results of a service review in a busy trauma hospital hand therapy department.

Method

Following a literature review and retrospective review of outcomes, new clinical guidelines for central slip injuries were developed. These were implemented with 22 patients referred to hand therapy for conservative management of closed central slip injuries during a one-year period.

Results

The majority of patients (72%) had either an excellent or good outcome using the Strickland-Glogovac outcome measure and an average total active motion of 90% compared to their unaffected hand.

Conclusions

The outcomes following implementation of new treatment guidelines following the service review are in line with the small amount of published data currently available. They provide detailed guidelines for the conservative management of closed central slip injuries in a busy out-patient setting.

Influence of diabetes on tissue healing in orthopaedic injuries

Diabetes is a group of metabolic diseases characterized by hyperglycaemia resulting from the defective action or secretion of insulin. Chronic hyperglycaemia can lead to the damage, dysfunction and failure of various organs. In the context of complications of healing and orthopaedic rehabilitation, vascular (microangiopathy) and nerve (neuropathy) disorders deserve particular attention. About 12% of the patients admitted to orthopaedic departments have diabetes. Studies indicate that there is an indisputable link between diabetes and: an increased risk of fractures, the difficult healing of injuries of bones, ligaments and musculotendinous. It appears that one of the main reasons for this is non-enzymatic glycosylation (glycation) of collagen molecules, a phenomenon observed in the elderly and diabetic populations, as it leads to the formation of advanced glycation end products (AGEs). Collagen is one of the major connective tissue components, and is therefore part of ligaments, tendons and bones. AGEs affect the weakening of its structure and biomechanical properties, and thus also affects the weakening of the structure and properties of the above-mentioned tissues. The aim of the study is to undertake an overview of the current knowledge of the impact of diabetes on the risk of some injuries and subsequent healing and rehabilitation of patients following orthopaedic injuries.

Foot and Ankle Surgery: Common Problems and Solutions

Participation in sports activity has increased significantly during the last several decades. This phenomenon has exposed orthopedic sports medicine surgeons to new challenges regarding the diagnosis and management of common sport-related injuries. Arthroscopy is becoming more commonly used in many of the surgical procedures for these injuries and carries the risk of complications. Wound and nerve complications make up the bulk of complications in most procedures. This article describes these complications associated with the common surgical procedures related to foot and ankle sport-related injuries and how to address and prevent them.

Metalloproteinase Changes in Diabetes

Matrix metalloproteinases (MMPs) constitute a group of over 20 structurally-related proteins which include a Zn(++) ion binding site that is essential for their proteolytic activities. These enzymes play important role in extracellular matrix turnover in order to maintain a proper balance in its synthesis and degradation. MMPs are associated to several physiological and pathophysiological processes, including diabetes mellitus (DM). The mechanisms of DM and its complications is subject of intense research and evidence suggests that MMPs are implicated with the development and progression of diabetic microvascular complications such as nephropathy, cardiomyopathy, retinopathy and peripheral neuropathy. Recent data has associated DM to changes in the tendon structure, including abnormalities in fiber structure and organization, increased tendon thickness, volume and disorganization obtained by image and a tendency of impairing biomechanical properties. Although not fully elucidated, it is believed that DM-induced MMP dysregulation may contribute to structural and biomechanical alterations and impaired process of tendon healing.

Tendinopathy in diabetes mellitus patients-Epidemiology, pathogenesis, and management

Chronic tendinopathy is a frequent and disabling musculo-skeletal problem affecting the athletic and general populations. The affected tendon is presented with local tenderness, swelling, and pain which restrict the activity of the individual. Tendon degeneration reduces the mechanical strength and predisposes it to rupture. The pathogenic mechanisms of chronic tendinopathy are not fully understood and several major non-mutually exclusive hypotheses including activation of the hypoxia-apoptosis-pro-inflammatory cytokines cascade, neurovascular ingrowth, increased production of neuromediators, and erroneous stem cell differentiation have been proposed. Many intrinsic and extrinsic risk/causative factors can predispose to the development of tendinopathy. Among them, diabetes mellitus is an important risk/causative factor. This review aims to appraise the current literature on the epidemiology and pathology of tendinopathy in diabetic patients. Systematic reviews were done to summarize the literature on (a) the association between diabetes mellitus and tendinopathy/tendon tears, (b) the pathological changes in tendon under diabetic or hyperglycemic conditions, and (c) the effects of diabetes mellitus or hyperglycemia on the outcomes of tendon healing. The potential mechanisms of diabetes mellitus in causing and exacerbating tendinopathy with reference to the major non-mutually exclusive hypotheses of the pathogenic mechanisms of chronic tendinopathy as reported in the literature are also discussed. Potential strategies for the management of tendinopathy in diabetic patients are presented.

Hormones and tendinopathies: the current evidence

BACKGROUND

Tendinopathies negatively affect the quality of life of millions of people, but we still do not know the factors involved in the development of tendon conditions.

SOURCES OF DATA

Published articles in English in PubMed and Google Scholar up to June 2015 about hormonal influence on tendinopathies onset. One hundred and two papers were included following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

AREAS OF AGREEMENT

In vitro and in vivo, tenocytes showed changes in their morphology and in their functional properties according to hormonal imbalances.

AREAS OF CONTROVERSY

Genetic pattern, sex, age and comorbidities can influence the hormonal effect on tendons.

GROWING POINTS

The increasing prevalence of metabolic disorders prompts to investigate the possible connection between metabolic problems and musculoskeletal diseases.

AREAS TIMELY FOR DEVELOPING RESEARCH

The influence of hormones on tendon structure and metabolism needs to be further investigated. If found to be significant, multidisciplinary preventive and therapeutic strategies should then be developed.

Complications of Tendon Surgery in the Foot and Ankle

This article discusses four subsets of patients that have an increased risk of complications from tendon surgery in the foot and ankle: smokers, diabetics, and patients with peroneal or Achilles tendon pathology. Very little has been published on the complications of other tendon surgeries in the foot and ankle other than Achilles tendon repair. Data can be extrapolated from the general orthopedic literature and animal studies to help guide therapy and treatment options. The foot and ankle surgeon must take into account the entirety of the history and physical examination to develop a treatment plan that optimizes each patient's chance for a complication-free recovery.

Does Diabetes Mellitus Affect Tendon Healing?

Diabetes mellitus (DM) is a metabolic disorder resulting from defective insulin production and characterized by chronic hyperglycemia. DM affects around 170 million people worldwide and its incidence is increasing globally. DM can cause a wide range of musculoskeletal disorders such as painful tendinopathies, tendon contracture, tendon rupture, and rotator cuff tear.In patients with diabetes neuropathy, diminished peripheral blood flow and decreased local angiogenesis are reported which probably are results of abnormalities in the production of collagen production, inflammatory mediators, angiogenic and growth factors and also contribute to lack of healing in damaged tissue. Abnormal or delayed wound healing is one of the main complications of both type-I and type-II DM.

The adverse effects of diabetes on osteoarthritis: update on clinical evidence and molecular mechanisms

Projected increases in the prevalence of both diabetes mellitus (DM) and osteoarthritis (OA) ensure their common co-existence. In an era of increasing attention to personalized medicine, understanding the influence of common comorbidities such as DM should result in improved care of patients with OA. In this narrative review, we summarize the literature addressing the interactions between DM and OA spanning the years from 1962 to 2014. We separated studies depending on whether they investigated clinical populations, animal models, or cells and tissues. The clinical literature addressing the influence of DM on OA and its therapeutic outcomes suggests that DM may augment the development and severity of OA and that DM increases risks associated with joint replacement surgery. The few high quality studies using animal models also support an adverse effect of DM on OA. We review strengths and weaknesses of the common rodent models of DM. The heterogeneous literature derived from studies of articular cells and tissues also supports the existence of biochemical and biomechanical changes in articular tissues in DM, and begins to characterize molecular mechanisms activated in diabetic-like environs which may contribute to OA. Increasing evidence from the clinic and the laboratory supports an adverse effect of DM on the development, severity, and therapeutic outcomes for OA. To understand the mechanisms through which DM contributes to OA, further studies are clearly necessary. Future studies of DM-influenced mechanisms may shed light on general mechanisms of OA pathogenesis and result in more specific and effective therapies for all OA patients.

Histological and biomechanical analysis of the effects of streptozotocin-induced type one diabetes mellitus on healing of tenotomised Achilles tendons in rats

BACKGROUND

Tendon healing is impaired in patient with diabetes mellitus. The effects of streptozotocin-induced type 1 diabetes (STZ-D) on the healing of the transected Achilles tendon in rats was studied.

METHODS

In the experimental group, type one diabetes was induced via administration of STZ. The right Achilles tendon of all the rats was transected 30 days after the STZ administration. The Achilles tendons were examined for biomechanical and histological examinations.

RESULTS

The statistical analysis showed that Young's modulus of elasticity and stress tensile load of the control group were significantly higher than those of the experimental group, and inflammation in the experimental group was significantly higher than that in the control group. At the same time, fibrosis in the experimental group was significantly lower than that of the control group.

CONCLUSION

Induction of type 1 diabetes by STZ significantly delayed the healing of the transected Achilles tendon in rats.

Protective effect of chemically modified SOD on lipid peroxidation and antioxidant status in diabetic rats

Reactive oxygen species mediated oxidative stress play an important role on the injury of tissue damage and increased attention has been focused on the role of free radicals in diabetes mellitus (DM). In the present study firstly superoxide dismutase (SOD) enzyme was chemically modified with two different polymer and physicochemical properties of these conjugates clearly analyzed. Then, the stability of carboxymethylcellulose-SOD (CMC-SOD) and poly methyl vinyl ether-co-maleic anhydride-SOD (PMVE/MA-SOD) conjugates was investigated against temperature and externally added H2O2. Moreover, we investigated the effect of chemically modified SOD enzyme on lipid peroxidation and antioxidant status in streptozotocin (STZ)-induced diabetic rats. PMVE/MA-SOD conjugate treatment significantly reduced MDA level compared with the control groups, native and CMC-SOD conjugate treated groups in brain, kidney and liver tissue. GSH and SOD enzyme activity in diabetic groups was significantly increased by treatment of CMC-SOD and PMVE/MA-SOD conjugates. The protective effects on degenerative changes in diabetic rats were also further confirmed by histopathological examination. This study provides the preventative activity of SOD-polymer conjugates against complication of oxidative stress in experimentally induced diabetic rats. These results suggest that chemically modified SOD is effective on the oxidative stress-associated disease and offer a therapeutic advantage in clinical use.

The effects of resveratrol on flap survival in diabetic rats

Resveratrol is an antioxidant agent with multiple positive impacts on the body. It is known to have anti-diabetic, anti-inflammatory, anti-carcinogenic, and neuroprotective effects. The goal of this study is to demonstrate the antioxidant and anti-diabetic effects of resveratrol on flap survival in diabetic rats. Streptozotocin-induced diabetic Sprague-Dawley albino rats were treated with 10 mg/kg resveratrol following a flap surgery. Histological findings regarding polymorphonuclear leukocyte (PMNL) density, vascular proliferation, fibroblast density, and tissue necrosis were compared between resveratrol-treated and control rats. Significantly higher PMNL density was found in the control group (p = 0.005); while vascular proliferation and the fibroblast density were higher in the resveratrol group (p = 0.004 and p = 0.021, respectively). Collagen density was also higher in the resveratrol group and the difference has statistical significance (p = 0.024). Lymphocyte density was not significantly different between groups (p = 0.061). When the necrosis in the distal areas was evaluated histologically, 20% of the resveratrol group had epidermal tissue necrosis, thus 90% of the control group had epidermal or full-layer necrosis. Resveratrol improved flap survival significantly in diabetic rats. Therefore, diabetic patients requiring complex reconstructive procedures may benefit from resveratrol; so, clinical trials are required to support this study.