Autologous growth factor injections in chronic tendinopathy: a systematic review

Efficacy of memantine prodrug microemulsion in a Preclinical model of tendinopathy

Tendinopathy is a complex musculoskeletal pathology characterized by pain and dysfunction in the tendon. Tendinopathy management includes pharmacological treatments, which, however, have numerous side effects and low efficacy. New pharmacological approaches are essential to overcome these drawbacks. This study aimed to test the activity of the newly synthesized memantine-prodrug Memit against chronic tendon pain, which releases H2S and memantine at the therapeutic site, formulated in a microemulsion for peri-tendon administration. Memit (1 % w/w) was successfully formulated in a microemulsion using the titration method, and the recovery was quantified by liquid chromatography. The characterization of the obtained Memit-loaded microemulsion (Memit-ME) by dynamic light scattering and electron microscopy showed the droplets' homogeneous dimensional dispersion and spherical shape. The formulation was found to be physically and chemically stable. Additionally, Memit-ME provided a prolonged release of the prodrug, essential to maintaining its retention at the therapeutic site. The formulation was administered in a rat model of tendon damage induced by a single intra-tendon carrageenan injection to evaluate its anti-hyperalgesic and anti-allodynic profile. The study demonstrated that, thanks to its safety profile and effectiveness in significantly reducing spontaneous pain and postural imbalance, the developed Memit-ME represents a promising approach for tendinopathy management.

Exercise for patellar tendinopathy

BACKGROUND

Patellar tendinopathy is a prevalent condition that commonly affects the tendon's origin, causing pain at the front of the knee. The main treatment for patellar tendinopathy involves different types of exercise (e.g. strengthening and stretching). The most common method of strengthening exercise is eccentric (lengthening) muscle loading. Strengthening exercises can be land-based or water-based, weight-bearing or non-weight-bearing, or both. Other treatments include surgery and glucocorticoid injections.

OBJECTIVES

To evaluate the benefits and harms of exercise for the treatment of patellar tendinopathy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and two trials registers to 5 September 2023, with no restrictions by language.

SELECTION CRITERIA

We included randomized controlled trials of strengthening exercise interventions compared to placebo or sham intervention; no treatment, usual care, or minimal intervention; or other active intervention. Strengthening exercises include concentric, eccentric, eccentric-concentric, and isometric exercises designed to enhance the strength and power of muscles.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, and assessed risk of bias and certainty of evidence using GRADE. Major outcomes included pain, function, participant-reported global assessment of treatment success, quality of life, return to sport, proportion of participants with adverse events, and proportion of participant withdrawals.

MAIN RESULTS

We included seven trials (211 participants with chronic patellar tendinopathy) comparing strengthening exercises with no treatment (3 trials, 93 participants), glucocorticoid injection (1 trial, 38 participants), surgery (1 trial, 40 participants), stretching exercise (1 trial, 15 participants), or pulsed ultrasound and transverse friction (1 trial, 30 participants). All trials included athletes (88% males, mean age 26 years) with a mean duration of symptoms of 41.6 months. Most trials were susceptible to bias, particularly selection bias/random sequence (57.1%), selection bias/allocation concealment (42.8%), detection bias (28.5%), attrition bias (71.4%), and selective reporting biases (28.5%). Given the nature of the intervention, neither participants nor investigators were blinded to group allocation in any trials (performance bias). We did not find any studies that compared exercise with placebo or sham intervention. Strengthening exercise versus no treatment We are very uncertain whether strengthening exercise reduces pain compared to no treatment. Mean pain with no treatment was 62.00 points on a 0 to 100 scale (0 = no pain) compared to 27.06 points with exercise (mean difference (MD) 34.94 points better, 95% confidence interval (CI) 20.94 better to 48.94 better; 1 study, 39 participants; very low-certainty evidence (downgraded twice for imprecision and once for bias)). Strengthening exercise may make little or no difference to function compared to no treatment at the end of treatment. Mean function with no treatment was 65.00 points on a 0 to 100 scale (100 = best function) compared to 72.04 points with exercise (MD 7.04 points better, 95% CI 6.94 points worse to 21.02 points better; 2 studies, 95 participants; low-certainty evidence (downgraded once for imprecision and once for bias)). The studies reported none of the other outcomes. Strengthening exercise versus glucocorticoid injection Strengthening exercise may make little or no difference to pain compared to glucocorticoid injection at the end of treatment. Mean pain with glucocorticoid injection was 18.00 points on a 0 to 100 scale (0 = no pain) compared to 24.04 points with exercise (MD 6.04 points worse, 95% CI 8.19 better to 20.26 better; 1 trial, 38 participants; low-certainty evidence (downgraded twice for imprecision)). Strengthening exercise may make little or no difference to function compared to glucocorticoid injection at the end of treatment. Mean function with no treatment was 82.00 points on a 0 to 100 scale (100 = best function) compared to 76.25 points with exercise (MD 5.75 points worse, 95% CI 17.41 worse to 5.93 better; 1 trial, 38 participants; low-certainty evidence (downgraded twice for imprecision)). The trial reported none of the other outcomes. Strengthening exercise versus surgery We are very uncertain whether strengthening exercise reduces pain compared to surgery at 12-month follow-up. Mean pain with surgery was 13.00 points on a 0 to 100 scale (0 = no pain) compared to 17.00 points with exercise (MD 4.00 points worse, 95% CI 4.06 better to 12.06 worse; 1 trial, 40 participants; very low-certainty evidence). We are very uncertain whether strengthening exercise improves function compared to surgery. Mean function in the surgery group at the end of treatment was 45.10 points on a 0 to 100 scale (100 = best function) compared to 52.4 points in the exercise group (MD 7.30 points better, 95% CI 5.02 worse to 19.62 better; 1 trial, 40 participants; very low-certainty evidence (downgraded once for bias and twice for serious imprecision)). Strengthening exercise may make little or no difference to treatment success compared to surgery at the end of treatment. The mean global assessment of treatment success with surgery was 0.2 points on a -5 to +5 scale (+5 maximum was improvement) compared to 1.76 points with exercise (MD 1.56 points better, 95% CI 0.52 worse to 3.64 better; 1 trial, 40 participants; low-certainty evidence (downgraded once for bias and once for imprecision)). Strengthening exercise may make little or no difference to the rate of participants who returned fully or partially to sport when compared to surgery at 12-month follow-up. The return to sport rate with surgery was 86% compared to 85% with exercise (risk ratio 1.02, 95% CI 0.78 to 1.34; 1 trial, 40 participants; low-certainty evidence (downgraded once for bias and once for imprecision)). The trial reported none of the other outcomes.

AUTHORS' CONCLUSIONS

We are very uncertain whether strengthening exercise reduces pain compared to no treatment. Strengthening exercise may make little or no difference to function compared to no treatment and to function or pain compared to glucocorticoid injection. Compared to surgery, we are very uncertain whether strengthening exercise reduces pain or improves function, and it may make little or no difference to treatment success and the proportion of athletes returning to sport. No trials measured adverse events. All trials analyzed in this review included participants who were athletes, limiting the findings to athletes rather than the general public.

Comparison of the Effectiveness of Autologous Blood Injection and Steroid Injection in Managing Tennis Elbow

Background Local depot steroid injections can consistently and predictably relieve tennis elbow pain in the short term. Prolotherapy, extracorporeal shockwave therapy, autologous blood, and local injections of platelet-rich plasma (PRP) are examples of novel treatment approaches. Objective The objective of this study is to compare the effectiveness of autologous blood injection and local steroid injection in providing pain relief for patients with lateral epicondylitis (tennis elbow) using the visual analog scale (VAS) over 12 weeks. Methods A descriptive case series was conducted from July 10, 2019, to July 9, 2021, at the Department of Orthopaedic and Spine Surgery, Ghurki Trust Teaching Hospital. A total of 396 patients with tennis elbow, aged 20 to 50 years, were included (198 in each group). Patients managed with non-operative methods and those with other associated injuries in the same elbow were excluded. Group I received an injection of 40 mg of methylprednisolone acetate with 1 ml of 2% lignocaine solution. Group II received an injection of 2 ml of autologous venous blood. The final outcome was assessed at 12 weeks. Results In Group I, the average age of the patients was 36.04 ± 8.26 years, while in Group II, it was 37.23 ± 7.32 years. The male-to-female ratio was 2.3:1; 276 (69.81%) of the 396 patients were male, while 120 (30.19%) were female. Group I's mean baseline VAS score was 6.99 ± 0.99, while Group II's mean baseline VAS score was 6.99 ± 1.06 (p = 1.000). Group I had a mean post-therapy VAS score of 3.11 ± 1.62, while Group II had a mean score of 2.48 ± 1.26 (p = 0.0001). About 118 (59.60%) individuals in Group I and 156 (78.79%) patients in Group II experienced pain alleviation from lateral epicondylitis (p = 0.0001). Conclusion This study found that autologous blood injection significantly reduces pain in patients with lateral epicondylitis compared to steroid injection, with a statistically significant p-value of 0.0001. Pain relief was more frequent in the autologous blood group (78.79%) than in the steroid group (59.60%). These findings suggest that autologous blood injections may offer a more effective treatment, reducing the need for repeat procedures and improving patient outcomes.

Platelet-rich plasma in the pathologic processes of tendinopathy: a review of basic science studies

Tendinopathy is a medical condition that includes a spectrum of inflammatory and degenerative tendon changes caused by traumatic or overuse injuries. The pathological mechanism of tendinopathy has not been well defined, and no ideal treatment is currently available. Platelet-rich plasma (PRP) is an autologous whole blood derivative containing a variety of cytokines and other protein components. Various basic studies have found that PRP has the therapeutic potential to promote cell proliferation and differentiation, regulate angiogenesis, increase extracellular matrix synthesis, and modulate inflammation in degenerative tendons. Therefore, PRP has been widely used as a promising therapeutic agent for tendinopathy. However, controversies exist over the optimal treatment regimen and efficacy of PRP for tendinopathy. This review focuses on the specific molecular and cellular mechanisms by which PRP manipulates tendon healing to better understand how PRP affects tendinopathy and explore the reason for the differences in clinical trial outcomes. This article has also pointed out the future direction of basic research and clinical application of PRP in the treatment of tendinopathy, which will play a guiding role in the design of PRP treatment protocols for tendinopathy.

Instantaneous self-healing and strongly adhesive self-adaptive hyaluronic acid-based hydrogel for controlled drug release to promote tendon wound healing

The treatment of tendon injuries is an important healthcare challenge. Irregular wounds, hypocellularity, and prolonged inflammation impede the rate of healing for tendon injuries. To address these problems, a high-tenacity shape-adaptive, mussel-like hydrogel (PH/GMs@bFGF&PDA) was designed and constructed with polyvinyl alcohol (PVA) and hyaluronic acid grafted with phenylboronic acid (BA-HA) by encapsulating polydopamine and gelatin microspheres containing basic fibroblast growth factor (GMs@bFGF). The shape-adaptive PH/GMs@bFGF&PDA hydrogel can quickly adapt to irregular tendon wounds, and the strong adhesion (101.46 ± 10.88 kPa) can keep the hydrogel adhered to the wound at all times. In addition, the high tenacity and self-healing properties allow the hydrogel to move with the tendon without fracture. Additionally, even if fractured, it can quickly self-heal and continue to adhere to the tendon wound, while slowly releasing basic fibroblast growth factor during the inflammatory phase of the tendon repair process, promoting cell proliferation, migration and shortening the inflammatory phase. In acute tendon injury and chronic tendon injury models, PH/GMs@bFGF&PDA significantly alleviated inflammation and promoted collagen I secretion, enhancing wound healing through the synergistic effects of its shape-adaptive and high-adhesion properties.

Effects of splinting and three injection therapies (corticosteroid, autologous blood and prolotherapy) on pain, grip strength, and functionality in patients with lateral epicondylitis

Objectives

This study aims to compare the efficacy of the wrist splint and the injection of corticosteroid, autologous blood, and hypertonic dextrose in the treatment of lateral epicondylitis (LE).

Patients and methods

A total of 120 patients (43 males, 77 females; mean age: 45.7±7.7 years; range, 18 to 65 years) diagnosed with LE between December 2013 and June 2015 were included in the study and randomized into four groups. The first group was administered 20 mg methylprednisolone acetate + 2 mL 2% prilocaine, the second group 2 mL venous blood + 0.5 mL prilocaine, and the third group 2 mL 30% dextrose + 0.5 mL prilocaine injections. A second injection was administered to the third group one month later. The fourth group was recommended to use only a wrist splint. Pre-treatment and post-treatment evaluations of the patients were carried out at one and six months by the Visual Analog Scale (VAS) in terms of pain, by Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire in terms of functional level, and by the Jamar dynamometer in terms of grip strength.

Results

In all groups, VAS values at one and six months after treatment were found to be lower in comparison to baseline. Except for the splint group, a significant improvement was observed in all three injection groups in terms of grip strength and PRTEE values at six months compared to the baseline values. In the comparison of the groups, no significant difference was observed in terms of improvement in VAS scores and grip strength. While corticosteroid injection was significantly effective in terms of PRTEE pain, function, and total scores only at one month, the autologous injection was effective in terms of PRTEE function and total scores at only six months after treatment. There were no significant differences for splint and prolotherapy groups in terms of PRTEE scores.

Conclusion

Corticosteroid injection, autologous blood injection, and prolotherapy are effective and safe long-term methods in LE treatment.

Bibliometric analysis of the top 50 highly cited articles on platelet-rich plasma in osteoarthritis and tendinopathy

The primary goal of this study was to compile the top 50 most cited articles on the use of platelet-rich plasma (PRP). A search of relevant studies was performed in accordance with the PRISMA guidelines in Web of Science. The top 25 most cited articles in osteoarthritis and tendinopathy were then compiled and evaluated. Level 1 evidence articles constituted the majority of the studies (64%) and were more likely to have a higher citation density. Altmetric data was highest for level 1 systematic reviews. Of the articles that report a positive outcome for PRP, 13% (2/16) had low risk of bias. This study defines the most cited and influential publications regarding PRP to further research in this area.

Healing effect of acellular fish skin with plasma rich in growth factor on full-thickness skin defects

Acellular skin as a scaffold has a good potential to regenerate or repair damaged tissues. Growth factors such as Plasma Rich in Growth Factor (PRGF) as a rich source of active proteins can accelerate tissue regeneration. In this study, an acellular scaffold derived from fish skin with growth factors was used to repair full-thickness skin defects in a rat model. Cellular results demonstrated that epithelial cells adhere well to acellular scaffolds. The results of animal studies showed that the groups treated with acellular scaffold and growth factor have a high ability to close and heal wounds on the 28th day after surgery. Histological and staining results showed that in the treated groups with scaffold and growth factor, an epidermal layer was formed with some skin appendages similar to normal skin. Overall, such scaffolds with biological agents can cause an acceptable synergistic effect on skin regeneration and wound healing.

Ulnar-Sided Wrist Pain in the Athlete: Sport-Specific Demands, Clinical Presentation, and Management Options

ABSTRACT

Ulnar-sided wrist injuries are common in sports that require repeated pronosupination, wrist radial/ulnar deviation, axial loading, and gripping equipment. Common anatomic structures affected include the triangular fibrocartilage complex, extensor carpi ulnaris tendon, distal radioulnar and ulnocarpal joints, and hamate bone. Presenting symptoms include pain with activity, swelling, possible snapping or clicking, and reproduction of symptoms with provocative maneuvers. Imaging may confirm or rule out pathologies, but abnormal findings also may present in asymptomatic athletes. Initial treatment is usually nonoperative with splinting, load management, activity modification, strengthening the components of the kinetic chain of the particular sport, and pain management. Surgery is usually indicated in ulnar-wrist pain pathology such as hook of hamate fractures and required in associated instability. Future research should address specific treatment and rehabilitation protocols, emphasizing the complete kinetic chain along with the injured wrist.

Enhancement of Migration and Tenogenic Differentiation of Macaca Mulatta Tendon-Derived Stem Cells by Decellularized Tendon Hydrogel

Decellularized tendon hydrogel from human or porcine tendon has been manufactured and found to be capable of augmenting tendon repair in vivo. However, no studies have clarified the effect of decellularized tendon hydrogel upon stem cell behavior. In the present study, we developed a new decellularized tendon hydrogel (T-gel) from Macaca mulatta, and investigated the effect of T-gel on the proliferation, migration and tenogenic differentiation of Macaca mulatta tendon-derived stem cells (mTDSCs). The mTDSCs were first identified to have universal stem cell characteristics, including clonogenicity, expression of mesenchymal stem cell and embryonic stem cell markers, and multilineage differentiation potential. Decellularization of Macaca mulatta Achilles tendons was confirmed to be effective by histological staining and DNA quantification. The resultant T-gel exhibited highly porous structure or similar nanofibrous structure and approximately swelling ratio compared to the collagen gel (C-gel). Interestingly, stromal cell-derived factor-1 (SDF-1) and fibromodulin (Fmod) inherent in the native tendon extracellular matrix (ECM) microenvironment were retained and the values of SDF-1 and Fmod in the T-gel were significantly higher than those found in the C-gel. Compared with the C-gel, the T-gel was found to be cytocompatible with NIH-3T3 fibroblasts and displayed good histocompatibility when implanted into rat subcutaneous tissue. More importantly, it was demonstrated that the T-gel supported the proliferation of mTDSCs and significantly promoted the migration and tenogenic differentiation of mTDSCs compared to the C-gel. These findings indicated that the T-gel, with its retained nanofibrous structure and some bioactive factors of native tendon ECM microenvironment, represents a promising hydrogel for tendon regeneration.

Cell-Free Book-Shaped Decellularized Tendon Matrix Graft Capable of Controlled Release of BMP-12 to Improve Tendon Healing in a Rat Model

BACKGROUND

Achilles tendon (AT) defects often occur in traumatic and chronic injuries. Currently, no graft can satisfactorily regenerate parallel tendinous tissue at the defect site to completely restore AT function.

PURPOSE

To develop a cell-free functional graft by tethering bone morphogenetic protein 12 (BMP-12) on a book-shaped decellularized tendon matrix (BDTM) and to determine whether this graft is more beneficial for AT defect healing than an autograft.

STUDY DESIGN

Controlled laboratory study.

METHODS

Canine patellar tendon was sectioned into a book shape and decellularized to fabricate a BDTM. The collagen-binding domain (CBD) was fused into the N-terminus of BMP-12 to synthesize a recombinant BMP-12 (CBD-BMP-12), which was tethered to the BDTM to prepare a cell-free functional graft (CBD-BMP-12/BDTM). After its tensile resistance, tenogenic inducibility, and BMP-12 release dynamics were evaluated, the efficacy of the graft for tendon regeneration was determined in a rat model. A total of 140 mature male Sprague-Dawley rats underwent AT tenotomy. The defect was reconstructed with reversed AT (autograft group), native BMP-12 tethered to an intact decellularized tendon matrix (IDTM; NAT-BMP-12/IDTM group), native BMP-12 tethered to a BDTM (NAT-BMP-12/BDTM group), CBD-BMP-12 tethered on an IDTM (CBD-BMP-12/IDTM group), and CBD-BMP-12 tethered on a BDTM (CBD-BMP-12/BDTM group). The rats were sacrificed 4 or 8 weeks after surgery to harvest AT specimens. Six specimens from each group at each time point were used for histological evaluation; the remaining 8 specimens were used for biomechanical testing.

RESULTS

In vitro CBD-BMP-12/BDTM was noncytotoxic, showed high biomimetics with native tendons, was suitable for cell adhesion and growth, and had superior tenogenic inducibility. In vivo the defective AT in the CBD-BMP-12/BDTM group regenerated more naturally than in the other groups, as indicated by more spindle-shaped fibroblasts embedded in a matrix of parallel fibers. The biomechanical properties of the regenerated AT in the CBD-BMP-12/BDTM group also increased more significantly than in the other groups.

CONCLUSION

CBD-BMP-12/BDTM is more beneficial than autograft for healing AT defects in a rat model.

CLINICAL RELEVANCE

The findings of this study demonstrate that CBD-BMP-12/BDTM can serve as a practical graft for reconstructing AT defects.

The Use of Platelet-Rich Plasma for Treatment of Tenodesmic Lesions in Horses: A Systematic Review and Meta-Analysis of Clinical and Experimental Data

The use of platelet-rich plasma (PRP) to enhance tenodesmic lesion healing has been questioned over the years. The aim of this study was to evaluate current literature to establish the effectiveness of PRP for treating tenodesmic lesions through a systematic review, in accordance with the PRISMA guidelines, and a meta-analysis. Studies comparing PRP with placebo or other treatments for horses with tenodesmic injuries or evaluated PRP effect on tendon and ligament explants were included. Outcomes were clinical, ultrasound, histologic, molecular evaluation, and adverse effects. Two authors independently extracted data and assessed each study's risk of bias. Treatment effects were evaluated using risk ratios for dichotomous data, together with 95% CI. Data were pooled using the random-effects model. The quality of the evidence for each outcome was assessed using GRADE criteria. Twenty-four trials met inclusion criteria for systematic review, while fifteen studies were included in the meta-analysis. Results showed no significant differences in the outcomes between PRP and control groups. Finally, there is no definitive evidence that PRP enhances tendons and ligaments healing. Therefore, there is a need for more controlled trials to draw a firmer conclusion about the efficacy of PRP as a treatment for tenodesmic lesions in the horse.

Biologics

Biologics are a growing field that has shown immense promise for the treatment of musculoskeletal conditions both in orthopedic sports medicine and interventional pain management. These procedures utilize injection of supraphysiologic levels of platelets and growth factors to invoke the body's own inflammatory cascade to augment the healing of many bony and soft tissue conditions. While many patients improve with conservative care, there is a need to address the gap between those that improve with rehabilitation alone and those who ultimately require operative management. Orthobiologic procedures have the potential to fill this void. The purpose of this review is to summarize the basic science, evidence for use, and post-injection rehabilitation concepts of platelet-rich plasma (PRP) and mesenchymal stromal cells (MSCs) as they pertain to joints, tendons, ligaments, and the spine.

Management of Achilles and patellar tendinopathy: what we know, what we can do

Tendinopathies are challenging conditions frequent in athletes and in middle-aged overweight patients with no history of increased physical activity. The term “tendinopathy” refers to a clinical condition characterised by pain, swelling, and functional limitations of tendons and nearby structures, the effect of chronic failure of healing response. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed primarily conservatively, obtaining good results and clinical outcomes, but, when this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively high rate of success with few complications. The purpose of this narrative review is to critically examine the recent available scientific literature to provide evidence-based opinions on these two common and troublesome conditions.

Platelet-rich plasma for treatment of chronic proximal hamstring tendinopathy

Aim: To determine whether platelet-rich plasma (PRP) can successfully treat symptoms associated with proximal hamstring tendinopathy. Materials & methods: Charts were retrospectively reviewed of patients with a diagnosis of chronic proximal hamstring tendinopathy who underwent an ultrasound-guided leukocyte-rich PRP injection to assess reported outcomes at baseline and final follow-up post-intervention. Results: In 22 patients with a mean age of 48.7 years and mean symptom duration of 26.5 months, mean Numeric Pain Rating Scale and Victorian Institute of Sport Assessment Scale for Proximal Hamstring Tendinopathy subscores demonstrated statistically significant improvements (p < 0.05) at a mean of 7.91 months follow-up. Sixty-eight percent of patients demonstrated ≥50% reduction of pain. Conclusion: Pain and functional outcomes improved following injection of PRP.

Adaptive and innate immune cell responses in tendons and lymph nodes after tendon injury and repair

Tendon injuries are a common clinical condition with limited treatment options. The cellular components of the innate immune system, such as neutrophils and macrophages, have been studied in tendon injuries. However, the adaptive immune system, comprising specialized lymphocytes, plays an important role in orchestrating the healing of numerous tissues, but less is known about these cells in tendon healing. To gain a greater understanding of the biological processes that regulate tendon healing, we determined how the cellular components of the adaptive and innate immune system respond to a tendon injury using two-month-old male mice. We observed that lymphatic vasculature is present in the epitenon and superficial regions of Achilles tendons, and that the lymphatics drain into the popliteal lymph node. We then created an acute Achilles tenotomy followed by repair, and collected tendons and popliteal lymph nodes 1, 2, and 4 wk after injury. Tendon injury resulted in a robust adaptive immune cell response that followed an initial innate immune cell response in tendons and lymph nodes. Monocytes, neutrophils, and macrophages initially accumulated at 1 wk after injury in tendons, while dendritic cells and CD4⁺ T cells peaked at 2 wk after injury. B cells and CD8⁺ T cells progressively increased over time. In parallel, immune cells of the popliteal lymph node demonstrated a similarly coordinated response to the injury. These results suggest that there is an adaptive immune response to tendon injury, and adaptive immune cells may play a role in regulating tendon healing.NEW & NOTEWORTHY While the innate immune system, consisting of macrophages and related hematopoietic cells, has been studied in tendon injury, less is known about the adaptive immune system. Using a mouse model of Achilles tendon tenotomy and repair, we observed an adaptive immune cell response, consisting of CD4⁺ and CD8⁺ T cells, and B cells, which occur through 4 wk after tendon injury. This response appeared to be coordinated by the draining popliteal lymph node.

Platelet-rich plasma for sports-related muscle, tendon and ligament injuries: an umbrella review

BACKGROUND

Platelet-rich plasma (PRP) has been used in different non-transfusion indications due to its role in tissue regeneration and healing. The aim of this overview of systematic reviews (umbrella review) is to provide a summary of the existing research syntheses related to PRP use for sports-related muscle, tendon and ligament injuries.

MATERIALS AND METHODS

Literature searches were performed in MEDLINE, Embase, and Cochrane Library to identify systematic reviews focusing on PRP use for sports-related muscle, tendon and ligament injuries. The methodological quality of included studies was assessed using the checklist for systematic reviews and research syntheses developed by the Joanna Briggs Institute and the GRADE assessment.

RESULTS

Twenty-two studies met the inclusion criteria. Five studies evaluated PRP use for acute muscle injury, and 17 evaluated PRP use for tendon and ligament injury. Studies were heterogeneous in terms of the dose and number of PRP injections, and the control groups. Three of the 5 reviews evaluating acute muscle injury concluded that PRP had no effect on the outcomes considered. One review shows superior efficacy of rehabilitation exercise compared to PRP. One review shows that PRP may result in an earlier return to sport for acute grade I-II injury. Eight out of the 17 reviews evaluating PRP for tendon and ligament injuries show a statistically significant (p<0.05) difference in pain and/or function outcome measures favouring PRP compared to controls, although most of the observed differences were small. Adverse events data and quality of life outcomes were rarely analysed or reported in the included studies and were considered clinically insignificant.

DISCUSSION

In most of the included reviews, the available evidence was judged to be of low/very low quality due to risk of bias, inconsistency and imprecision, thus making the level of certainty of these findings low and not adequate to support the general use of PRP in this setting.

Biomaterials for the Treatment of Tendon Injury

Background

Most tendon injuries are occurring from a gradual wearing and tearing of the tendon tissues from overuse. Such injuries are usually seen in sports, exercising, or daily activities that involve a high mechanical load and weight bearing. However, owing to the lack of both cellularity and blood vessels in tendons, the process of tendon repair is slow and inefficient. Although various conservative (non-surgical) and surgical management options are conducted by the clinicians, a gold standard of these approaches does not exist. In this regard, the treatment of tendon injuries is challenging.

Method

Here, we describe the recent advances of biomaterial-based approaches for the treatment of injured tendons.

Results

Regenerative medicine is an emerging multidisciplinary research that specializes in the repair of damaged tendon tissues through the delivery of regenerative factors by biomaterials.

Conclusion

Although current biomaterial-based treatment strategies have shown their potential for tendon healing, future research and clinical applications should focused on finding the optimum combinations of regenerative factors with ideal biomaterials for the repair of tendons.

Coll2-1 and Coll2-1NO2 as exemplars of collagen extracellular matrix turnover - biomarkers to facilitate the treatment of osteoarthritis?

Introduction: Osteoarthritis (OA) is the most common form of arthritis. However, there are no structure or disease-modifying OA drugs (DMOADs). Introducing personalized healthcare to patients and health-care practitioners is a high priority for the management of arthritic and musculoskeletal diseases. However, there are no biomarker tools that can be used for patient stratification, disease management, and drug development. Biomarkers are capable of diagnosing and prognosing some arthritic and musculoskeletal diseases. Cartilage-based biomarkers have the potential to be used in this context to guide the precision treatment of OA. Areas covered: The aim of this review is to focus on the pre-clinical and clinical utility of the Coll2-1 and Coll2-1NO2 biomarkers as unique cartilage-based biomarkers that can guide the development of new treatments for OA. This expert report will begin with a background to collagens and their important biomechanical roles in the musculoskeletal system, but particularly cartilage, before exploring the data and scientific evidence to support the utility of Coll2-1 and Coll2-1NO2 as unique biomarkers. Expert opinion: This review summarises the authors' expert view on the pre-clinical and clinical utility of the Coll2-1 and Coll2-1NO2 biomarkers and their potential for use as drug development tools.

Can platelet-rich plasma therapy save patients with ulnar collateral ligament tears from surgery?

Introduction

Platelet-rich plasma (PRP) has been shown to be effective in treating partial tears of the ulnar collateral ligament (UCL) of the elbow in overhead throwing athletes, but it is still unknown whether it has a role in complete tears. The aim of this study was to assess the effectiveness of PRP in treating complete as well as partial UCL tears. We hypothesized that trephination of the injured UCL followed by injection with PRP can promote healing of both partial and complete tears.

Methods

Thirty-four baseball players with partial or complete UCL tears confirmed by magnetic resonance imaging (MRI) were included in the study. They were all recalcitrant to more than two months of rest and physical therapy. Under ultrasound guidance, trephination of the UCL was performed using an 18-gauge needle, followed by PRP injection. Visual analog scale (VAS) scores, Disabilities of the Arm, Shoulder, and Hand (DASH) sports module scores, and sonographic ulnohumeral joint space measurements with valgus stress were all obtained prior to the procedure and six months after.

Results

Twenty-six of 30 athletes were able to return to sport with pre-injury level of play within six months after the procedure, at an average time of 12.4 weeks (range: 10-18). Four subjects needed surgical treatment for persistent UCL insufficiency. The average follow-up was 54.2 weeks (range: 26-148). The average VAS and DASH scores improved from 53.5 to 17.2 (p < 0.0001) and from 81.7 to 24.2 (p < 0.0001), respectively. The average ulnohumeral joint space opening with valgus stress decreased from 3.81 mm to 3.45 mm (p = 0.018). Subgroup analysis by injury location revealed that the average VAS score improved from 48.2 to 8.6 (p < 0.0001) and from 64.0 to 34.5 (p = 0.0023) in proximal and distal tears, respectively. The average DASH score improved from 83.8 to 17.8 (p = 0.0001) and from 77.5 to 36.7 (p < 0.0001) in proximal and distal tears, respectively. The average ulnohumeral joint space opening with valgus stress decreased from 3.64 to 3.21 mm (p = 0.003) and from 4.14 to 3.92 mm (p = 0.0023) in proximal and distal tears, respectively. There was one case with a proximal tear that needed surgical management for failure of treatment, while there were three cases needing surgery in those with distal tears.

Conclusion

Ultrasound-guided PRP injection following trephination can be an effective treatment option for both partial and complete UCL tears of the elbow, especially proximal tears. The use of this technique for complete UCL tears may allow more athletes to avoid surgery and enable them to return to play faster.

First clinical experience with a new injectable recombinant human collagen scaffold combined with autologous platelet-rich plasma for the treatment of lateral epicondylar tendinopathy (tennis elbow)

BACKGROUND

Lateral epicondylitis is a tendinopathy of the common extensor origin at the elbow. When traditional conservative treatment fails, more effective therapies are needed. Vergenix Soft Tissue Repair (STR) Matrix (CollPlant Ltd., Ness-Ziona, Israel) is an injectable gel composed of cross-linked bioengineered recombinant human type I collagen combined with autologous platelet-rich plasma (STR/PRP). The complex forms a collagen-fibrin matrix that promotes cell migration and tissue repair. Based on positive outcomes from preclinical trials, this study is the first clinical trial of STR/PRP on tendinopathy. We hypothesized that STR/PRP would be a safe and effective treatment for lateral epicondylar tendinopathy.

METHODS

Patients with chronic lateral epicondylitis underwent treatment with STR/PRP. Outcome assessment included grip strength, functional disability, and changes in sonographic tendon appearance for up to 6 months after treatment.

RESULTS

The study enrolled 40 patients. No systemic or local severe adverse events were reported. Clinical evaluation revealed an improvement in the mean Patient-Rated Tennis Elbow Evaluation score from 64.8 before treatment and showed a 59% reduction at 6 months. The 12-Item Short-Form Health Survey questionnaire showed improvement from a mean score of 30.7 to 37.7 at the final follow-up. Grip strength increased from 28.8 kg at baseline to 36.8 kg at 6 months. Improvements in sonographic tendon appearance were evident among 68% of patients.

CONCLUSION

STR/PRP is a safe treatment that effectively induces clinically significant improvements in elbow symptoms and general well-being as well as objective measures of strength and imaging of the common extensor tendon within 6 months of treatment of elbow tendinopathy recalcitrant to standard treatments.

Combined plasma rich in growth factors and adipose-derived mesenchymal stem cells promotes the cutaneous wound healing in rabbits

BACKGROUND

The use of Plasma Rich in Growth Factors (PRGF) and Adipose Derived Mesenchymal Stem Cells (ASCs) are today extensively studied in the field of regenerative medicine. In recent years, human and veterinary medicine prefer to avoid using traumatic techniques and choose low or non-invasive procedures. The objective of this study was to evaluate the efficacy of PRGF, ASCs and the combination of both in wound healing of full-thickness skin defects in rabbits. With this purpose, a total of 144 rabbits were used for this study. The animals were divided in three study groups of 48 rabbits each depending on the administered treatment: PRGF, ASCs, and PGRF+ASCs. Two wounds of 8 mm of diameter and separated from each other by 20 mm were created on the back of each rabbit: the first was treated with saline solution, and the second with the treatment assigned for each group. Macroscopic and microscopic evolution of wounds was assessed at 1, 2, 3, 5, 7 and 10 days post-surgery. With this aim, 8 animals from each treatment group and at each study time were euthanized to collect wounds for histopathological study.

RESULTS

Wounds treated with PRGF, ASCs and PRGF+ASCs showed significant higher wound healing and epithelialization rates, more natural aesthetic appearance, significant lower inflammatory response, significant higher collagen deposition and angiogenesis compared with control wounds. The combined treatment PRGF+ASCs showed a significant faster cutaneous wound healing process.

CONCLUSIONS

The combined treatment PRGF+ASCs showed the best results, suggesting this is the best choice to enhance wound healing and improve aesthetic results in acute wounds.

Concise Review: Stem Cell Fate Guided By Bioactive Molecules for Tendon Regeneration

Tendon disorders, which are commonly presented in the clinical setting, disrupt the patients' normal work and life routines, and they damage the careers of athletes. However, there is still no effective treatment for tendon disorders. In the field of tissue engineering, the potential of the therapeutic application of exogenous stem cells to treat tendon pathology has been demonstrated to be promising. With the development of stem cell biology and chemical biology, strategies that use inductive tenogenic factors to program stem cell fate in situ are the most easily and readily translatable to clinical applications. In this review, we focus on bioactive molecules that can potentially induce tenogenesis in adult stem cells, and we summarize the various differentiation factors found in comparative studies. Moreover, we discuss the molecular regulatory mechanisms of tenogenesis, and we examine the various challenges in developing standardized protocols for achieving efficient and reproducible tenogenesis. Finally, we discuss and predict future directions for tendon regeneration. Stem Cells Translational Medicine 2018;7:404-414.

Platelet Rich Plasma: New Insights for Cutaneous Wound Healing Management

The overall increase of chronic degenerative diseases associated with ageing makes wound care a tremendous socioeconomic burden. Thus, there is a growing need to develop novel wound healing therapies to improve cutaneous wound healing. The use of regenerative therapies is becoming increasingly popular due to the low-invasive procedures needed to apply them. Platelet-rich plasma (PRP) is gaining interest due to its potential to stimulate and accelerate the wound healing process. The cytokines and growth factors forming PRP play a crucial role in the healing process. This article reviews the emerging field of skin wound regenerative therapies with particular emphasis on PRP and the role of growth factors in the wound healing process.

Hyaluronic Acid

In recent times, the field of tissue engineering and regenerative medicine (TERM) has considerably increased the extent of therapeutic strategies for clinical application in orthopedics. However, TERM approaches have its rules and requirements, in the respect of the biologic response of each tissue and bioactive agents which need to be considered, respected, and subject of ongoing studies. Different medical devices/products have been prematurely available on the market and used in clinics with limited success. However, other therapeutics, when used in a serious and evidence-based approach, have achieved considerable success, considering the respect for solid expectations from doctors and patients (when properly informed).Orthobiologics has appeared as a recent technological trend in orthopedics. This includes the improvement or regeneration of different musculoskeletal tissues by means of using biomaterials (e.g., hyaluronic acid), stem cells, and growth factors (e.g., platelet-rich plasma). The potential symbiotic relationship between biologic therapies and surgery makes these strategies suitable to be used in one single intervention.However, herein, the recent clinical studies using hyaluronic acid (HA) in the treatment of orthopedic conditions will mainly be overviewed (e.g., osteochondral lesions, tendinopathies). The possibilities to combine different orthobiologic agents as TERM clinical strategies for treatment of orthopedic problems will also be briefly discussed.

Evaluation of a filter-prepared platelet concentrate for the treatment of suspensory branch injuries in horses

Objectives: Platelet preparations have become a treatment for soft tissue injuries in horses. This study evaluated a novel filter-based system to concentrate platelets and assesses its value in the treatment of suspensory ligament branch desmitis.

Methods: Filtered platelet concentrate was prepared from 55 ml of venous blood obtained from 21 normal horses. Platelets and white blood cells in whole blood and filtered platelet concentrate were measured, as was platelet activating factor (PAF)–induced platelet-derived growth factor-BB (PDGF-BB) release. Eleven horses with 18 focal acute suspensory ligament branch injuries were treated intra-lesionally with autologous filtered platelet concentrate and evaluated clinically and ultrasonographically for one to three years.

Results: The increase in concentration of platelets in the filtered concentrate in comparison with whole blood (6.9 ± 1.9-fold) was significantly greater than the increase in white blood cells (3.8 ± 0.8-fold) (p <0.0001). There was no effect of sex or breed on platelet concentration. Platelets were responsive to PAF with >100-fold higher levels of PDGF release over basal levels. All hypoechoic lesions re-evaluated within three months had resolved. Five of the 11 horses returned to their previous level of work, one was exercising at a lower level, three were retired, one died for unrelated reasons, and one was still convalescing.

Clinical significance: Filtered platelet concentrate was easily and reliably prepared and injected into suspensory ligament branch injuries without short-term complications. This treatment was associated with rapid resolution of ultrasonographic lesions and lameness. Filtered platelet concentrate represents a convenient alternative for the treatment of suspensory ligament branch injuries.

Noninsertional Tendinopathy of the Achilles

Noninsertional Achilles tendinosis is differentiated from insertional Achilles tendinosis based on anatomic location. Tendinosis, as opposed to tendonitis, is primarily a degenerative process and the role of inflammation is believed limited. The etiology of Achilles tendinopathy may include overuse leading to repetitive microtrauma, poor vascularity of the tissue, mechanical imbalances of the extremity, or combination of these elements. There is evidence to support eccentric exercise nonoperative management for patients with noninsertional Achilles tendinopathy. Operative treatment options include percutaneous longitudinal tenotomies, minimally invasive tendon scraping, open débridement and tubularization, and tendon augmentation with flexor hallucis longus.

Adipose-derived stem cells in orthopaedic pathologies

INTRODUCTION

To examine the current literature regarding the clinical application of adipose-derived stem cells (ADSCs) for the management of orthopaedic pathologies.

SOURCES OF DATA

MEDLINE,SCOPUS, CINAHL and EMBASE (1950 to April 14, 2017) were searched by two independent investigators for articles published in English. Reviews, meta-analyses, expert opinions, case reports, mini case series and editorials were excluded. Furthermore, we excluded animal studies, cadaveric studies and in vitro studies.

AREAS OF AGREEMENT

ADSCs seem to produce excellent clinical results. However, the length and modalities of follow-up in the different conditions are extremely variable. Nevertheless, it appears that the use of adipose-derived stem cells is associated with subjective and objective clinical improvements and minimal complication rates.

AREAS OF CONTROVERSY

None of the studies identified is a randomized double-blinded trial, and most of the selected studies present major limitations, and different methods, confounding the results of our review.

GROWING POINTS

It is necessary to conduct more and better studies to ascertain whether ADSCs really play a role in orthopaedic surgery with particular attention to ADSCs harvesting method, type of administration and the conditions treated.

AREAS TIMELY FOR DEVELOPING RESEARCH

The current literature regarding the use of ADSCs for orthopaedic pathologies is limited. At present, long-term safety is the biggest challenge of ADSCs based regenerative medicine.

LEVEL OF EVIDENCE

Level IV-Study of Level I, II, III, IV.

Effectiveness of Biologic Factors in Shoulder Disorders

Background:

Shoulder pathology can cause significant pain, discomfort, and loss of function that all interfere with activities of daily living and may lead to poor quality of life. Primary osteoarthritis and rotator cuff diseases with its sequalae are the main culprits. Management of shoulder disorders using biological factors gained an increasing interest over the last years. This interest reveals the need of effective treatments for shoulder degenerative disorders, and highlights the importance of a comprehensive and detailed understanding of the rapidly increasing knowledge in the field.

Methods:

This study will describe most of the available biology-based strategies that have been recently developed, focusing on their effectiveness in animal and clinical studies.

Results:

Data from in vitro work will also be briefly presented; in order to further elucidate newly acquired knowledge regarding mechanisms of tissue degeneration and repair that would probably drive translational work in the next decade. The role of platelet rich-plasma, growth factors, stem cells and other alternative treatments will be described in an evidence-based approach, in an attempt to provide guidelines for their clinical application. Finally, certain challenges that biologic treatments face today will be described as an initiative for future strategies.

Conclusion:

The application of different growth factors and mesenchymal stem cells appears as promising approaches for enhancing biologic repair. However, data from clinical studies are still limited, and future studies need to improve understanding of the repair process in cellular and molecular level and evaluate the effectiveness of biologic factors in the management of shoulder disorders.

Comparison of corticosteroid, autologous blood or sclerosant injections for chronic tennis elbow

OBJECTIVES

To compare three different ultrasound-guided injections for chronic tennis elbow.

DESIGN

Assessor-blinded, randomized controlled comparative trial.

METHODS

44 patients with clinically diagnosed tennis elbow, confirmed by Doppler ultrasound, received under ultrasound guidance, a single corticosteroid injection (n=14), or two injections (separated by 4 weeks) of either autologous blood (n=14) or polidocanol (n=16). Clinical and ultrasound examination was performed at baseline, 4, 12 and 26 weeks.

RESULTS

Complete recovery or much improvement was greater for corticosteroid injection than autologous blood and polidocanol at 4 weeks (p<0.001, number needed to treat 1 (95% CI 1-2)). In contrast, at 26 weeks corticosteroid was significantly worse than polidocanol (p=0.004, number needed to harm 2 (1-6)). Recurrence after corticosteroid injection was significantly higher than autologous blood or polidocanol (p=0.007, number needed to harm 2 (1-4)). Corticosteroid injection produced greater reduction in tendon thickness and vascularity than autologous blood at 4 weeks only. Compared to autologous blood, polidocanol reduced tendon thickness at 4 and 12 weeks and reduced echogenicity and hyperaemia after 12 or 26 weeks respectively.

CONCLUSIONS

Injections of corticosteroid cannot be recommended over polidocanol or autologous blood, because despite beneficial short-term effect there were inferior long-term effects. Whether polidocanol or autologous blood injections are effective is unknown, especially as their global effect profiles are not unlike previously reported for wait-and-see.

No evidence for the use of stem cell therapy for tendon disorders: a systematic review

INTRODUCTION

Stem cells have emerged as a new treatment option for tendon disorders. We systematically reviewed the current evidence for stem cell therapy in tendon disorders.

METHODS

Randomised and non-randomised controlled trials, cohort studies and case series with a minimum of 5 cases were searched in MEDLINE, CENTRAL, EMBASE, CINAHL, PEDro and SPORTDiscus. In addition, we searched grey literature databases and trial registers. Only human studies were included and no time or language restrictions were applied to our search. All references of included trials were checked for possibly eligible trials. Risk of bias assessment was performed using the Cochrane risk of bias tool for controlled trials and the Newcastle-Ottawa scale for case series. Levels of evidence were assigned according to the Oxford levels of evidence.

RESULTS

4 published and three unpublished/pending trials were found with a total of 79 patients. No unpublished data were available. Two trials evaluated bone marrow-derived stem cells in rotator cuff repair surgery and found lower retear rates compared with historical controls or the literature. One trial used allogenic adipose-derived stem cells to treat lateral epicondylar tendinopathy. Improved Mayo Elbow Performance Index, Visual Analogue Pain scale and ultrasound findings after 1-year follow-up compared with baseline were found. Bone marrow-derived stem cell-treated patellar tendinopathy showed improved International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score subscales and Tegner scores after 5-year follow-up. One trial reported adverse events and found them to be mild (eg, swelling, effusion). All trials were at high risk of bias and only level 4 evidence was available.

CONCLUSIONS

No evidence (level 4) was found for the therapeutic use of stem cells for tendon disorders. The use of stem cell therapy for tendon disorders in clinical practice is currently not advised.

Analysis of Platelet-Rich Plasma Extraction: Variations in Platelet and Blood Components Between 4 Common Commercial Kits

Background:

Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP.

Purpose:

To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons.

Study Design:

Controlled laboratory study.

Methods:

Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine.

Results:

Three kits taking samples from the “buffy coat layer” were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples.

Conclusion:

This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored, being considered insignificant. The lack of standardization of PRP preparation for clinical use has contributed at least in part to the varying clinical efficacy in PRP use.

Clinical Relevance:

The variation of platelet and other blood component concentrations between commercial PRP kits may affect clinical treatment outcomes. There is a need for standardization of PRP for clinical use.

The Effectiveness of Platelet-Rich Plasma in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Clinical Trials

BACKGROUND

Tendinopathy is very common in the general population. There are increasing numbers of clinical studies referring to platelet-rich plasma (PRP) and platelet-poor plasma (PPP) as treatments for tendinopathy.

PURPOSE

To perform a meta-analysis of the outcomes of the PRP groups by preparation method and injection technique in tendinopathy. To determine the clinical effectiveness of the preparations and to evaluate the effect of controls used in the studies reviewed.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The PubMed, EMBASE, CINAHL, and Medline databases were searched in March 2012, April 2014, and August 2015, and randomized controlled trials using autologous blood, PRP, PPP, or autologous conditioned plasma in tendinopathy with outcome measures of pain and follow-up time of 3 months were included in this review. Trials including surgery, tendon tears, and muscle or ligament injuries were excluded. Study quality was assessed using the Cochrane Collaboration risk-of-bias tool by 2 reviewers. Data were pooled using random-effects meta-analysis. The primary outcome measure was a change in pain intensity. Where more than 1 pain scale was included, a functional score was selected ahead of a visual analog scale score.

RESULTS

A total of 18 studies (1066 participants) were included. Eight studies were deemed to be at low risk of bias. The most significant outcomes in the PRP groups were seen in those treated with highly cellular leukocyte-rich PRP (LR-PRP) preparations: GPS kit (standardized mean difference [SMD], 35.75; 95% CI, 28.40-43.10), MyCells kit (SMD, 31.84; 95% CI, 17.56-46.13), Prosys kit (SMD, 42.99; 95% CI, 37.73-48.25), and unspecified LR-PRP (SMD, 34.62; 95% CI, 31.69-37.55). When the LR-PRP system types were grouped, there was a strongly positive effect (SMD, 36.38; 95% CI, 34.00-38.77) when compared with leukocyte-poor PRP (SMD, 26.77; 95% CI, 18.31-35.22). In assessing the control groups, there was no clear difference between different types of control injections: saline (SMD, 14.62; 95% CI, 10.74-18.50), local anesthetic (SMD, 15.00; 95% CI, 7.66-22.34), corticosteroid (SMD, 23.82; 95% CI, 10.74-18.50), or dry needling (SMD, 25.22; 95% CI, 21.27-29.16).

CONCLUSION

There is good evidence to support the use of a single injection of LR-PRP under ultrasound guidance in tendinopathy. Both the preparation and intratendinous injection technique of PRP appear to be of great clinical significance.

A Clinical, Biological, and Biomaterials Perspective into Tendon Injuries and Regeneration

Tendon injury is common and debilitating, and it is associated with long-term pain and ineffective healing. It is estimated to afflict 25% of the adult population and is often a career-ending disease in athletes and racehorses. Tendon injury is associated with high morbidity, pain, and long-term suffering for the patient. Due to the low cellularity and vascularity of tendon tissue, once damage has occurred, the repair process is slow and inefficient, resulting in mechanically, structurally, and functionally inferior tissue. Current treatment options focus on pain management, often being palliative and temporary and ending in reduced function. Most treatments available do not address the underlying cause of the disease and, as such, are often ineffective with variable results. The need for an advanced therapeutic that addresses the underlying pathology is evident. Tissue engineering and regenerative medicine is an emerging field that is aimed at stimulating the body's own repair system to produce de novo tissue through the use of factors such as cells, proteins, and genes that are delivered by a biomaterial scaffold. Successful tissue engineering strategies for tendon regeneration should be built on a foundation of understanding of the molecular and cellular composition of healthy compared with damaged tendon, and the inherent differences seen in the tissue after disease. This article presents a comprehensive clinical, biological, and biomaterials insight into tendon tissue engineering and regeneration toward more advanced therapeutics.

Treatment of midportion Achilles tendinopathy: an evidence-based overview

In Achilles tendinopathy, differentiation should be made between paratendinopathy, insertional- and midportion Achilles tendinopathy. Midportion Achilles tendinopathy is clinically characterized by a combination of pain and swelling at the affected site, with impaired performance as an important consequence. The treatment of midportion Achilles tendinopathy contains both non-surgical and surgical options. Eccentric exercise has shown to be an effective treatment modality. Promising results are demonstrated for extracorporeal shockwave therapy. In terms of the surgical treatment of midportion Achilles tendinopathy, no definite recommendations can be made.

LEVEL OF EVIDENCE

IV.

PRP IN THE TREATMENT OF TROCHANTERIC SYNDROME: A PILOT STUDY

OBJECTIVE

To compare the efficacy of platelet rich plasma (PRP) against corticosteroid on the treatment of trochanteric pain syndrome .

METHODS

From July 2011 to November 2012, eighteen patients (20 hips) with trochanter pain syndrome were randomized in two groups and treated with platelet rich plasma or triamcinolone infiltration guided by ultrasound. Pain and function were evaluated prior to the intervention and after 10, 30 and 60 days, through the Facial Expressions Scale for Pain and the Western Ontario McMaster and Harris Hip Score questionnaires. Inter-group analysis was performed by Student t-test and intragroup analysis by ANOVA, followed by Bonferroni post hoc test. Statistical significance was set at p <0.05 .

RESULTS

There was no difference between the groups. The triamcinolone group showed pain reduction (p=0.004) and improved function (p=0.036) through the Harris Hip Score questionnaire at 10, 30 and 60 days after treatment, when compared with the pre- intervention period. The platelet rich plasma group showed no statistical improvement in any of the variables .

CONCLUSION

Up to 60 days, PRP infiltration has no influence on pain relief and function improvement in trochanteric syndrome treatment. Level of Evidence II, Prospective Comparative Study.

Management of Lateral Elbow Tendinopathy: One Size Does Not Fit All

Synopsis Clear guidelines for the clinical management of individuals with lateral elbow tendinopathy (LET) are hampered by many proposed interventions and the condition's prognosis, ranging from immediate resolution of symptoms following simple advice in some patients to long-lasting problems, regardless of treatment, in others. This is compounded by our lack of understanding of the complexity of the underlying pathophysiology of LET. In this article, we collate evidence and expert opinion on the pathophysiology, clinical presentation, and differential diagnosis of LET. Factors that might provide prognostic value or direction for physical rehabilitation, such as the presence of neck pain, tendon tears, or central sensitization, are canvassed. Clinical recommendations for physical rehabilitation are provided, including the prescription of exercise and adjunctive physical therapy and pharmacotherapy. A preliminary algorithm, including targeted interventions, for the management of subgroups of patients with LET based on identified prognostic factors is proposed. Further research is needed to evaluate whether such an approach may lead to improved outcomes and more efficient resource allocation. J Orthop Sports Phys Ther 2015;45(11):938-949. Epub 17 Sep 2015. doi:10.2519/jospt.2015.5841.

Evidence for the Durability of Autologous Tenocyte Injection for Treatment of Chronic Resistant Lateral Epicondylitis: Mean 4.5-Year Clinical Follow-up

BACKGROUND

Chronic lateral epicondylitis (LE) induces cell apoptosis and autophagy, which lead to the reduction of tendon-derived cells in the torn tendon. Our previous study has shown that ultrasound-guided autologous tenocyte injection (ATI) to the torn tendon in patients with chronic resistant LE significantly improves pain, function, and structural repair at 1 year. This report is the continued assessment of the clinical outcomes of these patients at mean 4.5-year follow-up.

HYPOTHESIS

Improvements in LE clinical function and structural repair after ATI will be maintained at mean 4.5-year follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with severe refractory LE underwent clinical evaluation and MRI before intervention. A patellar tendon needle biopsy was performed under local anesthetic, and tendon cells were expanded by in vitro culture. Autologous tenocytes were injected into the central tendinopathy identified at the common extensor tendon origin under ultrasound guidance on a single occasion. Patients underwent serial clinical evaluations for up to 5 years after ATI, including the visual analog scale (VAS) for pain, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Upper Extremity Functional Scale (UEFS), and grip strength. Post-ATI MRI scanning was performed at 1 year and final follow-up.

RESULTS

A total of 16 patients (9 male, 7 female), aged between 37 and 63 years, were included in the study. The mean duration of symptoms before study recruitment was 29.24 months (range, 6-240 months). One patient elected to proceed to surgery 3 months after ATI due to reinjury at work, and 1 patient died of prostate cancer with metastases during the follow-up period. The mean final follow-up time for the remaining 15 patients was 4.51 years (range, 3.08-5.17 years). No complications were observed at the patellar tendon biopsy site for any patient. No adverse events, infection, or excessive fibroblastic reactions were observed in any patient at the injection site. Clinical evaluation revealed significant (P < .001) improvement in mean VAS pain score from 5.73 at initial assessment to 1.21 (78% improvement) at final follow-up. Mean QuickDASH, UEFS, and grip strength scores also significantly (P < .001) improved from initial assessment to final follow-up (from 45.88 to 6.61 [84%], from 31.73 to 9.20 [64%], and from 19.85 to 46.60 [208%], respectively). There was no difference in mean QuickDASH and UEFS scores at 1 year and final follow-up (P > .05); however, grip strength continued to improve (P < .001). A validated MRI scoring system indicated that the mean grade of tendinopathy at the common extensor origin improved significantly (P < .001) from initial assessment (4.31) to 1 year (2.88) and was maintained (P > .05) at final follow-up (2.87). At final follow-up, 93% of patients were either highly satisfied or satisfied with their ATI treatment.

CONCLUSION

ATI significantly improved clinical function and MRI tendinopathy scores for up to 5 years in patients with chronic resistant LE who had previously undergone unsuccessful nonsurgical treatment. This study provides evidence for the midterm durability of ATI for treatment of LE tendinopathy.

Continuous Shear Wave Elastography: A New Method to Measure Viscoelastic Properties of Tendons in Vivo

Viscoelastic mechanical properties are frequently altered after tendon injuries and during recovery. Therefore, non-invasive measurements of shear viscoelastic properties may help evaluate tendon recovery and compare the effectiveness of different therapies. The objectives of this study were to describe an elastography method for measuring localized viscoelastic properties of tendons and to discuss the initial results in healthy and injured human Achilles and semitendinosus tendons. The technique used an external actuator to generate the shear waves in the tendon at different frequencies and plane wave imaging to measure shear wave displacements. For each of the excitation frequencies, maps of direction-specific wave speeds were calculated using local frequency estimation. Maps of viscoelastic properties were obtained using a pixel-wise curve fit of wave speed and frequency. The method was validated by comparing measurements of wave speed in agarose gels with those obtained using magnetic resonance elastography. Measurements in human healthy Achilles tendons revealed a pronounced increase in wave speed as a function of frequency, which highlights the importance of tendon viscoelasticity. Additionally, the viscoelastic properties of the Achilles tendon were larger than those reported for other tissues. Measurements in a tendinopathic Achilles tendon indicated that it is feasible to quantify local viscoelastic properties. Similarly, measurement in the semitendinosus tendon revealed substantial differences in viscoelastic properties between the healthy and contralateral tendons. Consequently, this technique has the potential to evaluate localized changes in tendon viscoelastic properties caused by injury and during recovery in a clinical setting.

Tendinopathies and platelet-rich plasma (PRP): from pre-clinical experiments to therapeutic use

OBJECTIVES

The restorative properties of platelets, through the local release of growth factors, are used in various medical areas. This article reviews fundamental and clinical research relating to platelet-rich plasma applied to tendinous lesions.

MATERIALS AND METHOD

Articles in French and English, published between 1 January 2012 and 31 December 2014. dealing with PRP and tendons were searched for using the Medline and Scopus data bases.

RESULTS

Forty-seven articles were identified which addressed pre-clinical and clinical studies: 27 relating to in vitro and in vivo animal studies and 20 relating to human studies. Of these, five addressed lateral epicondylitis, two addressed rotator cuff tendinopathies, ten dealt with patellar tendinopathies and three looked at Achilles tendinopathies.

CONCLUSIONS

The majority of pre-clinical studies show that PRP stimulates the tendon's healing process. However, clinical series remain more controversial and level 1, controlled, randomised studies are still needed.

The past, present and future in scaffold-based tendon treatments

Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained release of therapeutics/biologics; and the ability to positively interact with the host to promote repair and regeneration. Herein, we critically discuss current therapies and emerging technologies that aim to transform tendon treatments in the years to come.

Study quality on groin injury management remains low: a systematic review on treatment of groin pain in athletes

Background

Groin pain in athletes is frequent and many different treatment options have been proposed. The current level of evidence for the efficacy of these treatments is unknown.

Objective

Systematically review the literature on the efficacy of treatments for groin pain in athletes.

Methods

Nine medical databases were searched in May 2014. Inclusion criteria: treatment studies in athletes with groin pain; randomised controlled trials, controlled clinical trials or case series; n>10; outcome measures describing number of recovered athletes, patient satisfaction, pain scores or functional outcome scores. One author screened search results, and two authors independently assessed study quality. A best evidence synthesis was performed. Relationships between quality score and outcomes were evaluated. Review registration number CRD42014010262.

Results

72 studies were included for quality analysis. Four studies were high quality. There is moderate evidence that, for adductor-related groin pain, active exercises compared with passive treatments improve success, multimodal treatment with a manual therapy technique shortens the time to return to sports compared with active exercises and adductor tenotomy improves treatment success over time. There is moderate evidence that for athletes with sportsman's hernia, surgery results in better treatment success then conservative treatment. There was a moderate and inverse correlation between study quality and treatment success (p<0.001, r=−0.41), but not between study quality and publication year (p=0.09, r=0.20).

Conclusions

Only 6% of publications were high quality. Low-quality studies showed significantly higher treatment success and study quality has not improved since 1985. There is moderate evidence for the efficacy of conservative treatment (active exercises and multimodal treatments) and for surgery in patients with adductor-related groin pain. There is moderate evidence for efficacy of surgical treatment in sportsman's hernia.

Long term results in refractory tennis elbow using autologous blood

Tennis elbow (TE) is one of the commonest myotendinosis. Different treatment options are available and autologous blood injection has emerged as the one of the acceptable modalities of treatment. Long term studies over a larger group of patients are however lacking. The purpose of this study was to evaluate these patients on longer durations. One-hundred and twenty patients of TE, who failed to respond to conventional treatment including local steroid injections were taken up for this prospective study over the period from year 2005 to 2011 and were followed up for the minimum of 3 years (range 3-9 years). Two mL of autologous blood was taken from the ipsilateral limb and injected into the lateral epicondyle. The effectiveness of the procedure was assessed by Pain Rating Sscale and Nirschl Staging, which was monitored before the procedure, at first week, monthly for first three months, at 6 months and then 3 monthly for first year, six monthly for next 2 years and then yearly. Statistical analysis was done and a P value of <0.05 was taken as significant. The patients (76 females and 44 males) were evaluated after procedure. The mean age group was 40.67±8.21. The mean follow up was 5.7±1.72 (range 3 to 9 years). The mean pain score and Nirschl stage before the procedure was 3.3±0.9 and 6.2±0.82 respectively. At final follow up the pain score and Nirschl were 1.1±0.9 and 1.5±0.91 respectively. Autologous blood injection was found to be one of the modalities for treatment of TE. Being cheap, available and easy method of treatment, it should be considered as a treatment modality before opting for the surgery. Universal guidelines for the management of tennis elbow should be made as there is lot of controversy regarding the treatment.