Treatment of chronic tendinopathy with ultrasound-guided needle tenotomy and platelet-rich plasma injection

The Use of Platelet-Rich Plasma in De Quervain's Tenosynovitis: A Systematic Review

De Quervain's disease (DQVD) is the stenosing tenosynovitis of tendons in the first extensor compartment of the forearm. It is a common inflammatory condition that is often treated conservatively. While conservative therapy is an effective modality of treatment for a large number of patients suffering from DQVD, some patients do not improve with conservative measures. Many alternative treatment modalities are recognized in the treatment of DQVD. One of the non-surgical treatment strategies that is currently on the rise is platelet-rich plasma (PRP) injections into the first dorsal extensor compartment. It is thought that PRP injections contain growth factors that may provide a regenerative stimulus to tendon healing. Various studies evaluated as a treatment modality for different tendinopathies including DQVD. There remains, however, controversy as to the efficacy of its benefit and efficacy in treating DQVD. This paper is a systematic review of the literature conducted to evaluate the effectiveness of PRP in the treatment of DQVD. The review was conducted in line with PRISMA guidelines for systematic reviews. The review included a systematic search through PubMed, Embase, Cochrane Library, Medline, Amed, and the Web of Sciences, and was supplemented by manual search through other published online resources. The period of search was defined as January 2013 to October 2023, and the search included all studies that evaluated the use of PRP in the treatment of DQVD. A total of 1,029 records were screened; only eight studies met the inclusion criteria and were included in the study. Three randomized clinical trials and five experimental studies were included in the review. A systematic review of the evidence suggested that PRP is a promising and safe alternative to conventional steroid injections in the treatment of De Quervain's tenosynovitis. Further large sample studies are needed prior to the definitive recommendation of PRP as the gold standard for the treatment of De Quervain's tenosynovitis.

Platelet-rich plasma for de Quervain’s tenosynovitis: A systematic review and meta-analysis

BACKGROUND

Platelet-rich plasma (PRP) injection is used as an alternative non-operative management for de Quervain’s tenosynovitis (DQT) to regenerate tendon healing.

AIM

To assess and conclude the research-based study systematically to analyse the efficacy of PRP on DQT.

METHODS

This systematic review used the Cochrane Handbook for Systematic Reviews and the guideline of preferred reporting items for systematic review and meta-analysis. A systematic literature search was applied to 11 databases. The authors assessed the study quality and risk of bias of each included study. Results of the meta-analysis were presented using mean difference (MD)/standardized mean difference (SMD) and 95% confidence interval (CI).

RESULTS

The authors evaluated 275 studies found in the literature search; 12 studies met the criteria for this review, and then the study quality and risk of bias were assessed. Pooled analysis of data from two studies involving 194 subjects with DQT showed that, compared with conservative treatment, PRP injection was associated with a greater reduction in visual analog scale pain in one month and six months after treatment (MD: -0.67, P value < 0.00001; MD: -1.16, P value < 0.00001) and the increase of Mayo’s wrist score in one month and six months after treatment (SMD: 3.72, P value < 0.00001; SMD: 4.44, P value < 0.00001).

CONCLUSION

PRP can be used as an alternative non-operative treatment for DQT due to the tissue regenerative effect of PRP.

Stem Cell‐Based Therapies and Tissue Engineering Innovations for Tendinopathy: A Comprehensive Review of Current Strategies and Future Directions

Tendon diseases commonly lead to physical disability, exerting a profound impact on the routine of affected patients. These conditions respond poorly to existing treatments, presenting a substantial challenge for orthopedic scientists. Research into clinical translational therapy has yet to yield highly versatile interventions capable of effectively addressing tendon diseases, including tendinopathy. Stem cell‐based therapies have emerged as a promising avenue for modifying the biological milieu through the secretion of regenerative and immunomodulatory factors. The current review provides an overview of the intricate tendon microenvironment, encompassing various tendon stem progenitor cells within distinct tendon sublocations, gene regulation, and pathways pertinent to tendon development, and the pathology of tendon diseases. Subsequently, the advantages of stem cell‐based therapies are discussed that utilize distinct types of autologous and allogeneic stem cells for tendon regeneration at the translational level. Moreover, this review outlines the challenges, gaps, and future innovations to propose a consolidated stem cell‐based therapy to treat tendinopathy. Finally, regenerative soluble therapies, insoluble bio‐active therapies, along with insoluble bio‐active therapies, and implantable 3D scaffolds for tendon tissue engineering are discussed, thereby presenting a pathway toward enhanced tissue regeneration and engineering.

Assessment of short-term effect of platelet-rich plasma treatment of tendinosis using texture analysis of ultrasound images

BACKGROUND

Computer-aided diagnosis (i.e., texture analyses) tools are becoming increasingly beneficial methods to monitor subtle tissue changes. The aim of this pilot study was to investigate short-term effect of platelet rich plasma (PRP) treatment in supraspinatus and common extensor of the forearm tendinosis by using texture analysis of ultrasound (US) images as well as by clinical questionnaires.

PATIENTS AND METHODS

Thirteen patients (7 male and 6 female, age 36-60 years, mean age 51.2 ± 5.2) were followed after US guided PRP treatment for tendinosis of two tendons (9 patients with lateral epicondylitis and 4 with supraspinatus tendinosis). Clinical and US assessment was performed prior to as well as 3 months after PRP treatment with validated clinical questionnaires. Tissue response in tendons was assessed by using gray level run length matrix method (GLRLM) of US images.

RESULTS

All patients improved of tendinosis symptoms after PRP treatment according to clinical questionnaires. Almost all GLRLM features were statistically improved 3 months after PRP treatment. GLRLM-long run high gray level emphasis (LRLGLE) revealed the best moderate positive and statistically significant correlation after PRP (r = 0.4373, p = 0.0255), followed by GLRLM-low gray level run emphasis (LGLRE) (r = 0.3877, p = 0.05).

CONCLUSIONS

Texture analysis of tendinosis US images was a useful quantitative method for the assessment of tendon remodeling after minimally invasive PRP treatment. GLRLM features have the potential to become useful imaging biomarkers to monitor spatial and time limited tissue response after PRP, however larger studies with similar protocols are needed.

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.

Total Healing of a Partial Rupture of the Supraspinatus Tendon Using Barbotage Technique Associated with Platelet-Rich Plasma: A Randomized, Controlled, and Double-Blind Clinical Trial

The prevalence of partial rotator cuff tears (PRCTs) is high in the general population. Our hypothesis is that barbotage, when associated with platelet-rich plasma (PRP), is an effective method for healing these tears. The aim of this study was to compare the effects of barbotage with or without PRP on the healing of partial supraspinatus tendon tears (PSTTs). This study assessed the Western Ontario Rotator Cuff Index score and ultrasound (US) images at 6 weeks and 6 months after treatment. Patients in both groups showed clinical improvement, with no significant difference in scores at 6 weeks. However, at 6 months, the PRP group exhibited significant improvement (p = 0.019). Both groups experienced a reduction in ST tear size, but the PRP group demonstrated a significant enhancement at 6 weeks and 6 months. In conclusion, the US-guided barbotage technique, whether associated with PRP or saline solution, proved to be an effective treatment for clinical improvement and reduction in the size of PSTT. Better clinical improvement results were observed with PRP at 6 months. The combination of PRP with barbotage was superior in reducing the size of the ST tear at both 6 weeks and 6 months, resulting in complete healing in 79.3% of the tears.

Nonoperative Treatment of the Biceps-Labral Complex

The long head of the biceps and superior labrum should be evaluated as an interdependent functional unit. A focused patient history and physical examination including multiple provocative tests should be performed alongside advanced imaging studies to obtain an accurate diagnosis. Nonoperative treatment modalities including nonsteroidal anti-inflammatory drugs, glucocorticoid injections, and a standardized physical therapy regimen should be exhausted before operative intervention. Significant improvements in pain, functional outcomes, and quality of life are achieved in patients treated nonoperatively. Although these outcomes are less consistent for overhead athletes, return to play and performance metrics seem comparable to those who undergo surgery.

Effectiveness of lyophilized growth factors injection for subacromial impingement syndrome: a prospective randomized double-blind placebo-controlled study

BACKGROUND

Platelet-derived lyophilized growth factors (L-GFs) use a standardized number of allogenic pathogen-free platelets instead of autologous platelets used in PRP as a source of growth factors. This study aimed to evaluate the efficacy of L-GF injection versus placebo in subacromial impingement (SIS) treatment.

METHODS

The current randomized double-blind placebo-controlled study included sixty patients (40 females and 20 males, aged between 24 and 75 years) diagnosed with SIS (both clinically and sonographically). Patients were randomly assigned to two equal groups. Under ultrasound guidance, group 1 received subacromial saline injection, and group 2 received L-GF injection. Clinical examination, pain visual analogue scale (VAS), shoulder pain and disability index (SPADI) and shoulder ultrasound were performed before and at the 8th week after injection.

RESULTS

Follow-up assessment showed statistically significant improvement in the L-GF group regarding active flexion, active and passive internal rotation and extension, SPADI-disability scale, VAS and thickness of the supraspinatus tendon by US. Regression analysis showed that group 1 was approximately 30 times more likely than the L-GF group to experience painful arc at follow-up. Both groups showed statistically significant improvement in SPADI-pain scale and SPADI-total, flexion and abduction (still the mean value of abduction was significantly higher in the L-GF group).

CONCLUSIONS

L-GF injection resulted in clinically significant reductions in pain and functional disability outcomes in patients with SIS. An objective significant reduction in the thickness of the supraspinatus tendon, measured by ultrasound, in the L-GF group hopefully encourages proper healing and functioning in SIS.

TRIAL REGISTRATION

The identification number is NCT04330027, date of first registration (01/04/2020). Unique on 21/11/2019, Protocol ID: 0106178.

ICON 2020-International Scientific Tendinopathy Symposium Consensus: A Systematic Review of Outcome Measures Reported in Clinical Trials of Achilles Tendinopathy

BACKGROUND

Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated.

OBJECTIVE

To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains.

DESIGN

Systematic review.

DATA SOURCES

Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series.

RESULTS

9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain.

CONCLUSION

233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures.

PROSPERO REGISTRATION

CRD42020156763.

Platelet-Rich Plasma Injection Associated With Microtenotomy in Lateral Epicondylitis – is a Tendon Tear Associated with the Therapeutic Response?

Objective

Ultrasound-guided platelet-rich plasma (PRP) injections, as well as needle tenotomy, are becoming increasingly popular in the treatment of epicondylitis. Whether ultrasound (US) findings predict the clinical benefit of these techniques is unclear at the moment. This study aimed to investigate the relationship between the presence of tendon tear assessed by US and the therapeutic response of the PRP injection following needle microtenotomy in patients with epicondylitis.

Methodology

This is a retrospective observational study. Twenty-six patients with chronic (>three months) lateral epicondylitis recalcitrant to conservative treatment or corticosteroid injection. Patients underwent US-guided microtenotomy followed by PRP injection. Data regarding gender, age, US findings at baseline, and numeric pain rating scale (NPRS) scores before and after intervention were collected. Pain improvement rates were calculated at several follow-up time points, namely one, three, six, and 12 months post-intervention. Results are stated as mean ± standard deviation.

Results

At the time of intervention, the mean age was 47.6±6.5 years, and 57.7% of patients were men. Overall, the mean initial NPRS score was 7.5±1.2, and there were no statistically significant differences in mean initial NPRS scores between the groups with or without tendon tear on the US imaging. The mean improvement rate at one, three, and six months was similar between patients with and without tendon tear. However, a statistically significant difference was observed at 12 months (73.1±37.6% vs. 16.0±21.9, p=0.029). 

Conclusions

Patients with tendon tear demonstrated a higher pain improvement rate at 12 months follow-up. This finding could predict the clinical response to this technique, thus allowing a better selection of the candidates.

Ultrasound-guided percutaneous needle tenotomy (PNT) alone versus PNT plus platelet-rich plasma injection for the treatment of chronic tendinosis: A randomized controlled trial

BACKGROUND

Tendinosis is a chronic degenerative condition. Current research suggests both percutaneous needle tenotomy (PNT) and leukocyte-rich platelet-rich plasma (LR-PRP) may be effective treatments for chronic tendinosis, but no studies have assessed the effectiveness of PNT alone versus PNT with intratendinous LR-PRP for multiple tendon types in a single study.

OBJECTIVE

To assess the efficacy of PNT versus PNT + LR-PRP to treat chronic tendinosis.

STUDY DESIGN

Double-blind, randomized, controlled comparative treatment study.

SETTING

Primary academic institution.

PARTICIPANTS

A convenience sample of 40 participants who had chronic tendinosis (rotator cuff, wrist extensor, wrist flexor, hip abductor, proximal hamstring, patellar, or Achilles) confirmed via ultrasound, failed conservative treatment, and did not have tendon tears, known coagulopathy, or systemic illnesses.

INTERVENTIONS

Participants were randomly assigned to PNT (n = 19) or PNT + LR-PRP (n = 21). Participants and outcomes assessors were blinded to treatment assignments. PNT was performed with 20-30 passes of a 22-gauge needle under ultrasound guidance, with 1% lidocaine given outside the tendon. LR-PRP was processed from whole blood (30-60 mL) and injected into the affected tendon using the same PNT technique.

MAIN OUTCOME MEASURES

Primary outcome was current numerical rating scale pain at 6 weeks. Secondary outcomes were average pain, function, general well-being, and sleep quality at 6, 52, and 104 weeks.

RESULTS

Baseline characteristics were similar between groups. Overall, there were no significant differences between groups over time for any of the outcomes (P > .05). Between-group analyses showed significantly lower current and average pain after PNT compared to PNT + LR-PRP at 6 weeks (estimated-mean [SE]: 3.1[0.4] vs. 4.6[0.6], P = .04; 3.4[0.4] vs. 4.9[0.5], P = .03) only. Adverse event rates were low (PNT-3.9%; PNT + LR-PRP-5.0%) and related primarily to postprocedural pain and inflammation.

CONCLUSIONS

Although pain scores were lower after PNT compared to PNT + LR-PRP at 6 weeks, there were no between-group differences in outcomes at 52 or 104 weeks.

Biologic therapies for foot and ankle injuries

Introduction: The use of orthobiologics as supplemental treatment for foot and ankle pathologies have increased in the past decades. They have been used to improve the healing of bone and soft tissue injuries. There have been several studies that examined the use of biologics for knee and hip pathologies but the foot and ankle construct has unique features that must be considered.Areas covered: The biologics for foot and ankle injuries that are covered in this review are platelet-rich plasma (PRP), stem cells, growth factors, hyaluronic acid, bone grafts, bone substitutes, and scaffolds. These modalities are used in the treatment of pathologies related to tendon and soft tissue as well as cartilage.Expert opinion: The utilization of biological adjuncts for improved repair and regeneration of ankle injuries represents a promising future in our efforts to address difficult clinical problems. The application of concentrated bone marrow and PRP each represents the most widely studied and commonly used injection therapies with early clinical studies demonstrating promising results, research is also being done using other potential therapies such as stem cells and growth factors; further investigation and outcome data are still needed.

Molecular and Structural Effects of Percutaneous Interventions in Chronic Achilles Tendinopathy

Achilles tendinopathy (AT) is a common problem, especially in people of working age, as well as in the elderly. Although the pathogenesis of tendinopathy is better known, therapeutic management of AT remains challenging. Various percutaneous treatments have been applied to tendon lesions: e.g., injectable treatments, platelet-rich plasma (PRP), corticosteroids, stem cells, MMP inhibitors, and anti-angiogenic agents), as well as percutaneous procedures without any injection (percutaneous soft tissue release and dry needling). In this review, we will describe and comment on data about the molecular and structural effects of these treatments obtained in vitro and in vivo and report their efficacy in clinical trials. Local treatments have some impact on neovascularization, inflammation or tissue remodeling in animal models, but evidence from clinical trials remains too weak to establish an accurate management plan, and further studies will be necessary to evaluate their value.

Ultrasound-Guided Iliopsoas Tendon Release: A Cadaveric Investigation

BACKGROUND

The iliopsoas is a common source of anterior hip pain. Refractory cases may require surgical intervention, with reported complication rates ranging from 3% to 50%. Development of a minimally invasive, outpatient method of iliopsoas tendon release is desirable and may reduce costs, lower complications, and improve recovery time.

OBJECTIVE

To describe and evaluate the safety and reproducibility of an ultrasound-guided (USG) iliopsoas tendon release using a spinal needle in a cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Academic Institution Procedural Skills Laboratory.

PARTICIPANTS

Five unembalmed cadaveric specimens (three female, two male), 69 to 93 years of age (mean 83.2 years), with a mean body mass index (BMI) of 24.5 kg/m² (range 19.2 to 30.3 kg/m² ).

INTERVENTIONS

Two operators each performed five USG iliopsoas tendon releases. Three additional investigators dissected the pelves to assess completeness of tendon release and damage to adjacent structures.

MAIN OUTCOME MEASURES

Successful transection, completeness (%) of the tendon transection, damage to adjacent structures, and procedural time.

RESULTS

Nine of 10 releases achieved the target release of ≥75% tendon transection. One procedure achieved 50% tendon release. No injury to adjacent structures was identified. The mean duration of the procedure was 6.19 minutes.

CONCLUSIONS

USG iliopsoas tendon release can be performed in a cadaveric model, consistently achieve the desired percentage of tendon release, does not result in injury to adjacent neurovascular structures, and takes approximately 6 minutes to perform. Although results cannot be generalized to a clinical setting, due to the minimally invasive nature of the procedure, it is likely that this procedure can be performed safely in an outpatient setting under local anesthesia, will cost less, and will facilitate a more rapid recovery when compared to standard surgical procedures. Further research is warranted for clinical application.

Post-Procedure Protocols Following Platelet-Rich Plasma Injections for Tendinopathy: A Systematic Review

OBJECTIVE

Platelet-rich plasma (PRP) has been increasingly studied as a treatment for tendinopathy. Many factors may influence outcomes after PRP, including different protocols following administration. It was hypothesized that there would be heterogeneity in post-PRP protocols.

LITERATURE SURVEY

A systematized review of the literature on post-PRP protocols for tendinopathy was conducted using an electronic search of MEDLINE and Embase databases through September 2018.

METHODOLOGY

After duplicates were removed, English language articles involving adult patients who received PRP for tendinopathy were reviewed. Exclusion criteria included studies with fewer than 10 patients, PRP used to treat pathology other than tendinopathy, multiple protocols in one study, and surgical settings. Protocol specifics were extracted including nonsteroidal anti-inflammatory drugs (NSAID) restrictions before and after injection, postinjection restrictions on movement and weight bearing, use of orthoses, activity modifications, and postinjection rehabilitation protocols. Given limitations in the data, a meta-analysis was not performed.

SYNTHESIS

Eighty-four studies met inclusion criteria. Following PRP injection, weight-bearing restrictions were mentioned rarely (12% of protocols). Orthosis use was uncommon overall (18%) but more common in Achilles tendinopathy protocols (53%). The majority of protocols instituted a period of stretching (51%) and strengthening (54%). Stretching programs generally began 2-7 days following injection, and strengthening programs began within 2-3 weeks. Preinjection NSAID restriction was reported rarely (20%), whereas postinjection NSAID restriction was more common (56%), with a typical restriction of greater than 2 weeks (38%). Return to play or full activity was reported in 42% of protocols, most commonly at 4-6 weeks following injection.

CONCLUSION

Although the clinical effectiveness of PRP remains controversial, even less is known about the effect of post-PRP protocols, which may affect the outcomes attributed to PRP itself. No studies directly compare post-PRP protocols, and the protocols studied demonstrate substantial heterogeneity. Some consensus regarding post-PRP protocols exists, although the rationale for these recommendations is limited.

Platelet Concentrates in Musculoskeletal Medicine

Platelet concentrates (PCs), mostly represented by platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are autologous biological blood-derived products that may combine plasma/platelet-derived bioactive components, together with fibrin-forming protein able to create a natural three-dimensional scaffold. These types of products are safely used in clinical applications due to the autologous-derived source and the minimally invasive application procedure. In this narrative review, we focus on three main topics concerning the use of platelet concentrate for treating musculoskeletal conditions: (a) the different procedures to prepare PCs, (b) the composition of PCs that is related to the type of methodological procedure adopted and (c) the clinical application in musculoskeletal medicine, efficacy and main limits of the different studies.

Brief Ultrasound-Aided Teaching to Improve the Accuracy and Confidence of Resident Musculoskeletal Palpation

BACKGROUND

Multiple studies demonstrate poor musculoskeletal palpation accuracy of physiatry residents. With the growing use of ultrasound clinically, it could serve as a powerful educational tool. However, there are no published studies examining the efficacy of ultrasound-aided education at the bedside, where much learning takes place during postgraduate training.

OBJECTIVE

To determine if brief ultrasound-aided teaching improves residents' accuracy and confidence of musculoskeletal palpation.

DESIGN

Before/After Trial.

SETTING

Academic Institution.

PARTICIPANTS

Ten physical medicine and rehabilitation residents were voluntary participants.

INTERVENTION

Each resident was given a survey to assess confidence in palpating the hook of the hamate and medial calcaneal tubercle. They then attempted to palpate and place a marker over these two structures in a model patient. Marker placement accuracy was verified by ultrasound. Faculty spent less than 1 minute per landmark, sonographically teaching its correct localization. The resident, after moving to a new model patient, was then re-tested on accurate marker placement for both landmarks. A repeat survey to assess confidence was administered.

MAIN OUTCOME MEASUREMENTS

Preintervention and postintervention accuracy and confidence of correct localization of both landmarks.

RESULTS

We used McNemar's and Wilcoxon's tests to determine whether the intervention improved the location accuracy and confidence of successful palpation, respectively. Confidence level of correct localization of two landmarks improved on average from 4.3 to 8.15 on a scale of 10 after intervention. Of 20 palpation attempts, 11 correctly placed the marker postintervention after an incorrect placement, 8 made no change, and one changed from correct to incorrect placement. The odds of improvement in accuracy was 11 (95% confidence interval [CI] 1.60-473.47, P < .01). Both tests showed significant improvements after the intervention at the significance level of .05.

CONCLUSIONS

Brief, ultrasound-aided teaching increases accuracy and confidence of residents' musculoskeletal palpation.

Platelet rich plasma compared to dry needling in the treatment of non-insertional Achilles tendinopathy

OBJECTIVES

The efficacy of platelet rich plasma in the treatment of Achilles tendinopathy is controversial. Despite positive results observed in open studies, randomized controlled trials failed to show difference against saline or rehabilitation. Aims of this retrospective observational study were to compare the efficacy of platelet-rich plasma and dry needling and to assess possible differences age and sex-related.

METHODS

Groups of 46 and 38 patients with non-insertional Achilles tendinopathy were treated with platelet-rich plasma and dry needling (once a week for 3 weeks), respectively. At baseline, 3 and 6 months, pain and function scores and the percentage of satisfactory outcomes were evaluated. Sub-group analyses were performed according to age and sex.

RESULTS

At 3 and 6 months no differences in terms of pain and function between groups were observed, but the percentage of subjects reporting satisfactory results, at 6 months, was higher in platelet rich plasma group. Better results were observed in younger subjects, with a greater reduction of pain, improvement of function, and accordingly of the percentage of positive outcomes. A trend toward better results was also observed in males.

CONCLUSION

Beneficial effects of platelet rich plasma and dry needling in non-insertional Achilles tendinopathy have been observed only in some subjects, but not in others; platelet rich plasma shows a slight superiority against dry needling, mainly in younger persons; finally, a gender difference in the therapeutic response can be hypothesized.

Predictors of Outcome Following Tenotomy in Patients with Recalcitrant Epicondylopathy

BACKGROUND

Elbow tendinopathies are associated with tenderness, pain, and functional disability with ensuing socioeconomic costs. There is lack of consensus regarding the best treatment for patients recalcitrant to first-line conservative treatments. Percutaneous needle tenotomy is considered a regenerative approach that injures the tendon to elicit a healing response.

OBJECTIVE

To investigate whether demographic characteristics, clinical factors, baseline sonographic entities, or their interactions are related to the likelihood of responding positively to needle tenotomy over a 1-year follow-up period.

DESIGN

Prospective case series.

SETTING

Tertiary institutional hospital.

PARTICIPANTS

Patients with elbow tendinopathy for whom conservative treatments had failed and who had persistent symptoms lasting for at least 3 months.

METHODS

Patients underwent needle tenotomy with or without PRP followed by a lighter needle tenotomy within a 2-week interval as part of treatment.

MAIN OUTCOME MEASUREMENTS

Disabilities of the Arm, Shoulder and Hand (DASH) and Visual Analogue Scale for pain (VAS-P) scores were assessed before intervention (baseline) and at 6 weeks and 3, 6, and 12 months after intervention. A generalized linear mixed effects model was created to examine whether injectate type, clinical, demographic, or pretreatment sonographic entities or their interactions influenced clinical outcomes.

RESULTS

The authors analyzed 74 elbows (71 patients). At baseline, analyzed patients (mean age: 49.48 years; 51.35% women) scored 43.30 and 5.83 on the DASH and VAS-P, respectively. Pretreatment tendon vascularization was a predictor of pain (P = .011) and DASH score changes (P = .019). The linear mixed effect model revealed that male gender and hypercholesterolemia were associated with enhanced functional recovery, (P = .020 and P < .001, respectively). Moreover, the interactions between pretreatment vascular status (P = .039), echotexture (P = .037) and enthesophytes (P = .028) influenced the temporal pattern of functional recovery after needle tenotomy.

CONCLUSIONS

Baseline patient characteristics, such as gender and hypercholesterolemia, along with ultrasound features may be predictive of outcomes following needle tenotomy for elbow tendinopathy.

LEVEL OF EVIDENCE

IV (NCT01945528).

[Insertional Achilles tendinopathy : Differentiated diagnostics and therapy]

Achilles tendinopathy at the calcaneal insertion is classified into insertional tendinopathy, retrocalcaneal and superficial bursitis. The aim of this study was to present the current evidence on conservative and surgical treatment of insertional tendinopathy of the Achilles tendon. Conservative first-line therapy includes reduction of activity levels, administration of non-steroidal anti-inflammatory drugs (NSAID), adaptation of footwear, heel wedges and orthoses or immobilization. In addition, further conservative therapy options are also available. Eccentric stretching exercises should be integral components of physiotherapy and can achieve a 40% reduction in pain. Extracorporeal shock wave therapy has been shown to reduce pain by 60% with a patient satisfaction of 80%. Due to the limited evidence, injections with platelet-rich plasma (PRP), dextrose (prolotherapy) or polidocanol (sclerotherapy) cannot currently be recommended. Operative therapy is indicated after 6 months of unsuccessful conservative therapy. Open debridement allows all pathologies to be addressed, including osseous abnormalities and intratendinous necrosis. The success rate of over 70% is contrasted by complication rates of up to 40%. The Achilles tendon should be reattached, if detached by >50%. No valid data are available for the transfer of the tendon of the flexor hallucis longus (FHL) muscle but it is frequently applied in cases of more than 50% debridement of the diameter of the Achilles tendon. Lengthening of the gastrocnemius muscle cannot be recommended because insufficient data are available. Tendoscopy is a promising treatment option for isolated retrocalcaneal bursitis and has shown similar success rates to open debridement with significantly lower complication rates.

Real-time sonoelastography evaluation of the Achilles tendon following ultrasound-guided platelet-rich plasma injection and eccentric exercise for the treatment of refractory Achilles tendinopathy

The objective of this study was to investigate the feasibility of using sonoelastography to depict Achilles tendon stiffness after platelet-rich plasma injection and eccentric exercise for chronic Achilles tendinopathy, and to correlate sonoelastography findings with clinical outcome up to 12 months after treatment. Forty-five Achilles tendons from 45 patients (33 males, 12 females; mean age 51 years) were examined using sonoelastography and ultrasound at baseline, 4-6 weeks, 6 months and 12 months post-treatment. The strain ratio (between Achilles tendon and Kager's fat) during sonoelastography was obtained. The proportion of tendons with hypoechogenicity and neovascularity were documented. Clinical outcomes were assessed by the Victorian Institute of Sport Assessment-Achilles questionnaire and correlated with sonographic findings. The Victorian Institute of Sport Assessment-Achilles improved significantly from 38.4 (±14.1) at baseline, 77.2 (±12.5) at 6 months (p < 0.001) to 81.2 (±10.8) at 12 months (p < 0.001). The strain ratio values were 2.16 (±1.02) at baseline, 2.03 (±0.67) at 4-6 weeks, 1.81 (±0.62) at 6 months and 1.19 (±0.34) at 12 months with a significant reduction observed at 6 months (p = 0.006) and 12 months (p < 0.001). At 12-month evaluation, none of the tendons regained a normal echotexture. Strain ratio demonstrated a moderately good inverse correlation with Victorian Institute of Sport Assessment-Achilles (r = -0.610, p<0.001) while B-mode and Doppler ultrasound did not show a significant correlation (r = -0.041, p = 0.817, and r = -0.116, p = 0.514). Achilles tendon stiffness shows moderately good correlation with clinical symptom at 12-month post-treatment. Sonoelastography using strain ratio could be a promising ancillary tool for monitoring Achilles tendon healing after treatment.

Myths and Facts of In-Office Regenerative Procedures for Tendinopathy

Tendinopathy carries a large burden of musculoskeletal disorders seen in both athletes and aging population. Treatment is often challenging, and progression to chronic tendinopathy is common. Physical therapy, nonsteroidal anti-inflammatory drugs, and corticosteroid injections have been the mainstay of treatment but are not optimal given that most tendon disorders seem to involve degenerative changes in addition to inflammation. The field of regenerative medicine has taken the forefront, and various treatments have been developed and explored including prolotherapy, platelet rich plasma, stem cells, and percutaneous ultrasonic tenotomy. However, high-quality research with standardized protocols and consistent controls for proper evaluation of treatment efficacy is currently needed. This will make it possible to provide recommendations on appropriate treatment options for tendinopathy.

Platelet-rich plasma: myth or reality?

Platelet-rich plasma (PRP) is a preparation for therapeutic purposes that is increasingly accepted for various musculoskeletal disorders, due to its theoretical potential to repair tissues with poor healing capacity. Several randomised clinical trials have investigated the capacity of PRP to repair tendons, ligaments, muscles and cartilage, and to date there is level 1a evidence to support its use for lateral epicondylitis, osteoarthritis of the knee, plantar fasciitis and rotator cuff tendinopathy; and level 1b for patellar tendinopathy and osteoarthritis of the hip. Retrospective cohort studies and case series describe promising results with PRP for treating other musculoskeletal disorders. Since its side effects are fewer than those of the control groups, the treatment is considered practically harmless and is being increasingly used. Further randomised clinical trials are necessary to establish future indications, and to confirm effectiveness and safety.

Regenerative Sports Medicine: Past, Present, and Future (Adapted From the PASSOR Legacy Award Presentation; AAPMR; October 2016)

Regenerative medicine has shown dramatic expanse and evolution in the past decade. Within that milieu, physiatrists are taking an active role in research, clinical care delivery, and education. The purpose of this review is to provide a balance among evidence, theory, experience, clinical trends, and the foreseeable future. We focus on the literature that reports the research with the best methodology in each practice area, recognizing that the level of evidence varies substantially among different treatment modalities and conditions. The following elements are included: an overview of the evolution of currently available regenerative techniques, evidence base for each available modality (prolotherapy, platelet rich plasma, bone marrow aspirate concentrate and stem cells, adipose-derived stem cells, and amniotic tissue products), general principles in the application of these treatments, and discussion and a vision of what lies ahead. We expect that practitioners will use this review to facilitate clinical decision making and to provide a core knowledge base to assist when counseling patients. LEVEL OF EVIDENCE: IV.

Regional Rheumatic Disorders and Rehabilitation in Older Adults: An Update

Musculoskeletal problems are the most frequently reported complaints among older adults living in the community. The impact of the aging process on skeletal muscles and joints can have a profound effect on the ability of individuals to function. This article reviews the rehabilitation medicine approach to the evaluation of older adults with regional rheumatic disorders and the rehabilitation medicine considerations for clinical intervention. Future research is required to gain a greater understanding of the subject matter and its impact on the provision of care and patients' quality of life.

Platelet-rich plasma in tendon-related disorders: results and indications

PURPOSE

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.

METHODS

A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies.

RESULTS

The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative).

CONCLUSION

Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders.

LEVEL OF EVIDENCE

Systematic review of level I-IV trials, Level IV.

Ultrasonic Percutaneous Tenotomy of Common Extensor Tendons for Recalcitrant Lateral Epicondylitis

Tennis elbow is a common musculoskeletal condition affecting middle-aged patients with symptoms usually lasting from 6 months to 2 years. The vast majority of individuals will respond to conservative therapy; however, some will require surgical intervention. A new treatment system has been developed for use with ultrasound guidance in the ultrasonic microresection of tendinopathic tissue. This technology has been implemented in the TX1 Tissue Removal System and is used to treat various tendinopathies by debridement using targeted ultrasonic energy. We describe the surgical technique for the TX1 system as well as provide pain and functional outcome scores for a series of patients with recalcitrant lateral epicondylitis treated with percutaneous tenotomy with ultrasonic energy utilizing ultrasound guidance.

Nonoperative treatment of five common shoulder injuries: A critical analysis

Economic pressure highlights the critical need for appropriate diagnosis and treatment of various shoulder pathologies since under-diagnosis and under-treatment can result in increased costs to society in the form of disability and lost production. On the other hand, aggressive over-treatment can further inflate already burgeoning health-care costs and potentially harm the patient. Therefore, it is crucial to distinguish the indications between operative and nonoperative management, especially in common shoulder pathologies such as rotator cuff tears, anterior shoulder instability, biceps tendinitis, lesions to the acromioclavicular joint, and proximal humeral fractures. As a result, a detailed analysis of individual risk factors for potential failures should be performed and treatment should be based on individualized care with consideration given to each patient’s particular injury pattern, functional demands, and long-term goals.

Platelet-Rich Plasma Injection With Percutaneous Needling for Recalcitrant Lateral Epicondylitis: Comparison of Tenotomy and Fenestration Techniques

Background

Recalcitrant lateral epicondylitis (LE) is a common debilitating condition, with numerous treatment options of varying success. An injection of platelet-rich plasma (PRP) has been shown to improve LE, although it is unclear whether the method of needling used in conjunction with a PRP injection is of clinical importance.

Purpose

To determine whether percutaneous needle tenotomy is superior to percutaneous needle fenestration when each is combined with a PRP injection for the treatment of recalcitrant LE.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 93 patients with recalcitrant LE were treated with a PRP injection and percutaneous needle fenestration (n = 45) or percutaneous needle tenotomy (n = 48) over a 5-year study interval. Preoperative patient data, including visual analog scale for pain (VAS-P), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Patient-Rated Tennis Elbow Evaluation (PRTEE) scores and grip strength, were obtained from a chart review and compared with postoperative values obtained prospectively. Secondary outcomes included the incidence of complications, need for additional interventions, return to work, and patient satisfaction.

Results

At a mean follow-up of 40 months, significant improvements in VAS-P (mean, -6.1; 95% CI, -6.8 to -5.5; P < .0001), QuickDASH (mean, -46; 95% CI, -52 to -40; P < .0001), and PRTEE (mean, -57; 95% CI, -64 to -50; P < .0001) scores and grip strength (mean, +6.1 kg; 95% CI, 4.9 to 7.3; P < .0001) were observed across the entire study cohort, with no significant differences noted between the fenestration and tenotomy groups. Nine of 45 patients (22%) underwent additional procedures to treat recurrent symptoms in the fenestration group compared with 5 of 48 patients (10%) in the tenotomy group (P = .05). No complications occurred in any patients, and no patients expressed dissatisfaction with their treatment course.

Conclusion

A PRP injection with concomitant percutaneous needling is an effective treatment for recalcitrant LE, with sustained improvements in pain, strength, and function demonstrated at a mean follow-up of longer than 3 years. Although the method of concomitant needling does not appear to have a significant effect on treatment outcomes, more aggressive needle tenotomy is less likely to require conversion to open tenotomy than needle fenestration in the short term to midterm.

Lengthening of knee flexor muscles by percutaneous needle tenotomy: Description of the technique and preliminary results

Background

Knee flexion contractures occur frequently in non-ambulatory, aged persons and persons with central nervous system lesions, rendering positioning and nursing care difficult. There are often risks associated with surgical interventions.

Objective

To evaluate the effectiveness of percutaneous needle tenotomy to lengthen the knee flexor muscles and improve passive function.

Methods

This was a retrospective study of all patients who underwent percutaneous needle tenotomy between 2012 and 2014. Tenotomy was carried out in the semi-tendinosus, biceps femoris and gracillis muscles under local anesthesia. The procedure took no more than 40 minutes. Range of motion (ROM) was evaluated immediately post-operatively and 3 months later.

Results

Thirty-four needle tenotomies were carried out. Mean lack of knee extension was 94.2° (range 35–120°) pre-op, (range 15–90°; p<0.05) immediately post-op and 50.1° (range 10–90°; p<0.05) three months later, thus a mean increase of 44.1° knee extension (range 0–90°). All care and positioning objectives were achieved. There were no complications and procedure-related pain was rated as 3-4/ 10.

Conclusions

Needle tenotomy was well tolerated and yielded a significant increase in ROM with no unwanted effects. All objectives were achieved. This technique could be used in an ambulatory care setting or within institutions for severely disabled individuals.

Outcomes of prolotherapy for intra-tendinous Achilles tears: a case series

BACKGROUND

The intra-tendinous tear is a new pathology that is defined as a discontinuity of fibres situated entirely within the tendon. Prolotherapy involves injecting an irritant, such as hyperosmolar dextrose, to stimulate a tissue healing response and ultimately reduce pain.

METHODS

43 consecutive patients diagnosed with an intra-tendinous tear were included (27 males: 16 females, mean (SD) age 41 (11.3). Patients were injected with 0.4ml-1.5ml (mean 0.8ml) of 50% dextrose and 0.5% marcaine mixed in a 1:1 ratio. A 4-6 week period of walking boot immobilisation was followed by progressive rehabilitation (6-8 weeks). Outcomes were assessed with a VISA-A questionnaire at baseline, 3 months and a mean 12.6 (7.0) months post-treatment. Ultrasound scans were conducted before treatment and 5.2 (2.3) weeks later to assess sonographic changes.

RESULTS

30 patients (70%) responded with VISA-A scores increasing by 31 (30.5) points after 3 months (f=0.62, p<0.05) and by 40 (29.3) points after 12.60 (7.0) months (f=0.87, p<0.05). After 5.2 (2.3) weeks, echogenicity was significantly reduced (p<0.05) and 27% of tears were no longer detectable. No significant differences were observed in remaining tears with respect to tear size, tendon thickness or neovascularisation.

CONCLUSION

Treatment resulted in clinically significant improvements and controlled trials are warranted.

LEVEL OF EVIDENCE

IV.

Percutaneous planter fasciitis release under local anesthesia: A prospective study

PURPOSE

Plantar fasciitis is the most common cause of pain on the bottom of the heel. It occurs when the strong band of the tissue supporting the arch of foot becomes irritated and inflamed. The majority of patients can be treated conservatively but some resistant cases need surgery eventually. This study aims to evaluate the outcome results of percutaneous planter fascia release under local anesthesia for chronic planter fasciitis.

METHODS

This prospective study was conducted in the Department of Orthopaedic Surgery in the School of Medical Science and Research, Sharda University, India from December 2010 to December 2013. Totally 78 patients with planter fasciitis for more than 6-12 months were recruited from the outpatient department. All patients were operated on under local anesthesia and followed up for a year.

RESULTS

The clinical results were evaluated in terms of pain, activity level and patient satisfaction. Pain relief was achieved averagely at eight weeks after surgery. The results were excellent in 88.46% (69/78) patients and good in 6.41% (9/78) patients. Neither complications of lateral column instability, sinus tarsitis and metatarsalgia nor wound-related complications were encountered. On subjective evaluations, 88.46% (69/78) patients reported full satisfaction and 6.41% (9/78) reported partial satisfaction after treatment.

CONCLUSION

Percutaneous planter fasciitis release under local anesthesia is a minimally invasive procedure that can be performed in the outpatient setting. It is easy, quick, effective and moreover with few complications.

Advanced Ultrasound-Guided Interventions for Tendinopathy

Tendinopathy is increasingly recognized as an important cause of musculoskeletal pain and disability. Tendinopathy is thought to be principally a degenerative process, rather than inflammatory as was traditionally believed. Consequently, traditional tendinopathy treatments focused solely on decreasing inflammation have often been ineffective or even harmful. The advancement of ultrasonography as for guidance of outpatient musculoskeletal procedures has facilitated the development of novel percutaneous procedures for the treatment of tendinopathy, mostly by using mechanical intervention to stimulate regeneration. Several of these techniques, including percutaneous needle tenotomy, percutaneous ultrasonic tenotomy, high-volume injection, and percutaneous needle scraping, are reviewed in this article.

Follow-up of surgical and minimally invasive treatment of Achilles tendon pathology: a brief diagnostic imaging review

The follow-up of an operated tendon is primarily clinical, although clinical examination may not be sufficient in the presence of certain complications. The imaging techniques are of great value not only in the diagnosis of tendon pathologies, but also as an adjunct to clinical evaluation. This is particularly true in the follow-up of patients submitted to surgical tendon reconstruction, by monitoring morphological effects of different interventions and evaluating tendon healing processes. Interpretation of imaging findings requires knowledge of the imaging appearance of the operated tendon during the healing phase, to distinguish between normal postsurgical changes and real pathology, as well as knowledge of surgical technique, postoperative course (including type of prescribed therapy) and possible postoperative complications. The most important imaging modalities to examine the Achilles tendon are ultrasound and magnetic resonance imaging. This article gives a review of some of the most common treatment strategies for Achilles tendon pathology, expected postoperative imaging findings and postoperative complications.

What can be seen after rotator cuff repair: a brief review of diagnostic imaging findings

Diagnostic imaging plays an important role in the postoperative evaluation of the rotator cuff, as pain and disability may occur or persist after treatment. Postoperative imaging is therefore of paramount importance for clinicians before planning additional treatments. Multimodality imaging of the postoperative shoulder includes radiography, magnetic resonance (MR) imaging, MR arthrography, computed tomography (CT), CT arthrography, and ultrasound. Correct interpretation of imaging findings of the postoperative shoulder necessitates that the radiologist be familiar with the various treatment strategies, their possible complications and sources of failure, knowledge of normal and abnormal postoperative findings, and awareness of the advantages and weaknesses of the different imaging techniques. Imaging findings, however, should always be correlated with the clinical presentation because postoperative imaging abnormalities do not necessarily correlate with symptoms. This manuscript is a review of some of the most common treatment strategies for rotator cuff pathology, with a focus on expected postoperative imaging findings and postoperative complications.

Regional Rheumatic Disorders and Rehabilitation in Older Adults

Musculoskeletal problems are the most frequently reported complaints among older adults living in the community. The impact of the aging process on skeletal muscles and joints can have a profound effect on the ability of individuals with and without disabilities to function. This article reviews the rehabilitation medicine approach to the evaluation of older adults with regional rheumatic disorders, and the rehabilitation medicine considerations for clinical interventions. Future research considerations are encouraged in order to gain a greater understanding of the subject matter and its impact on the provision of care and patients' quality of life.

PRP Treatment Efficacy for Tendinopathy: A Review of Basic Science Studies

Platelet-Rich Plasma (PRP) has been widely used in orthopaedic surgery and sport medicine to treat tendon injuries. However, the efficacy of PRP treatment for tendinopathy is controversial. This paper focuses on reviewing the basic science studies on PRP performed under well-controlled conditions. Both in vitro and in vivo studies describe PRP's anabolic and anti-inflammatory effects on tendons. While some clinical trials support these findings, others refute them. In this review, we discuss the effectiveness of PRP to treat tendon injuries with evidence presented in basic science studies and the potential reasons for the controversial results in clinical trials. Finally, we comment on the approaches that may be required to improve the efficacy of PRP treatment for tendinopathy.

Platelet-Rich Plasma in a Murine Model: Leukocytes, Growth Factors, Flt-1, and Muscle Healing

BACKGROUND

It is well known that platelet-rich plasma (PRP) preparations are not the same and that not all preparations include white blood cells, but the part that leukocytes play on the healing role of PRP is still unknown.

PURPOSE

The primary aim of this study was to evaluate the influence of leukocytes in different PRP preparations with a special emphasis on growth factor concentrations. The secondary aim was to evaluate the influence of PRP on muscle healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

Two PRP preparation procedures were evaluated. Blood fractions were stained with Rapid Panoptic, and growth factors (transforming growth factor beta 1 [TGF-β1], vascular endothelial growth factor [VEGF], insulin-like growth factor [IGF], epidermal growth factor [EGF], hepatocyte growth factor [HGF], and platelet-derived growth factor [PDGF]) were quantified by enzyme-linked immunosorbent assay. Western blotting analysis was performed for Fms-related tyrosine kinase 1 (Flt-1). A muscle contusion injury was created and treated with PRP at different time points.

RESULTS

Leukocytes were the main source of VEGF, and all other growth factors measured had a higher concentration in the preparations that included the buffy coat and consequently had a higher concentration of white blood cells. Flt-1 was also found in platelet-poor plasma (PPP). There were higher concentrations of PDGF and HGF in the preparations that encompassed the buffy coat. A PRP injection 7 days after the injury provided significantly increased exercise performance and decreased the fibrotic area when compared with other PRP-treated groups.

CONCLUSION

VEGF is only present in PRP's buffy coat, while Flt-1 is present in PPP. A PRP injection 7 days after an injury resulted in improved exercise performance.

CLINICAL RELEVANCE

The presence of Flt-1 in PRP provides yet another explanation for results described in the literature after a PRP injection. This information is relevant for selecting the best PRP for each type of injury.