Platelet-rich plasma treatment for ligament and tendon injuries

Histological study of the influence of plasma rich in growth factors (PRGF) on the healing of divided Achilles tendons in sheep

BACKGROUND

The use of plasma rich in growth factors (PRGF) has been proposed to improve the healing of Achilles tendon injuries, but there is debate about the effectiveness of this therapy. The objective of the present study was to evaluate the histological effects of PRGF, which is a type of leukocyte-poor platelet-rich plasma, on tendon healing.

METHODS

The Achilles tendons of twenty-eight sheep were divided surgically. The animals were randomly divided into four groups of seven animals each. The repaired tendons in two groups received an infiltration of PRGF intraoperatively and every week for the following three weeks under ultrasound guidance. The tendons in the other two groups received injections with saline solution. The animals in one PRGF group and one saline solution group were killed at four weeks, and the animals in the remaining two groups were killed at eight weeks. The Achilles tendons were examined histologically, and the morphometry of fibroblast nuclei was calculated.

RESULTS

The fibroblast nuclei of the PRGF-treated tendons were more elongated and more parallel to the tendon axis than the fibroblast nuclei of the tendons in the saline solution group at eight weeks. PRGF-treated tendons showed more packed and better oriented collagen bundles at both four and eight weeks. In addition to increased maturation of the collagen structure, fibroblast density was significantly lower in PRGF-infiltrated tendons. PRGF-treated tendons exhibited faster vascular regression than tendons in the control groups, as demonstrated by a lower vascular density at eight weeks.

CONCLUSIONS

PRGF was associated with histological changes consistent with an accelerated early healing process in repaired Achilles tendons in sheep after experimental surgical disruption. PRGF-treated tendons showed improvements in the morphometric features of fibroblast nuclei, suggesting a more advanced stage of healing. At eight weeks, histological examination revealed more mature organization of collagen bundles, lower vascular densities, and decreased fibroblast densities in PRGF-treated tendons than in tendons infiltrated with saline solution. These findings were consistent with a more advanced stage of the healing process.

CLINICAL IMPLICATIONS

Based on the findings in this animal model, PRGF infiltration may improve the early healing process of surgically repaired Achilles tendons.

Low-level laser therapy combined with platelet-rich plasma on the healing calcaneal tendon: a histological study in a rat model

The objective of this study was to investigate the effects of low-level laser therapy (LLLT) treatment alone (λ = 660 nm and λ = 830 nm) or associated with platelet-rich plasma (PRP). We used 54 male rats divided into six groups, with nine animals each: group 1, partial tenotomy; group 2 (GII), PRP; group 3 (GIII): λ660 nm; group 4 (GIV), λ830 nm; group 5 (GV), PRP + λ660 nm; and group 6 (GVI), PRP + λ830 nm. The protocol used was power density 0.35 W/cm(2), energy 0.2 J, energy density 7.0 J/cm(2), time 20 s per irradiated point, and number of points 3. Animals in groups GII, GV, and GVI received treatment with PRP, consisting of a single dose of 0.2 mL directly into the surgical site, on top of the tenotomy. Animals were killed on the 13th day post-tenotomy and their tendons were surgically removed for a quantitative analysis using polarization microscopy. The percentages of collagen fibers of types I and III were expressed as mean ± SD. Higher values of collagen fibers type I were obtained for groups GV and GVI when compared with all other groups (p < 0.05), whereas groups GIII and GIV showed no significant difference between them (p > 0.05). For collagen type III, a significant difference was observed between GII and all other groups (p < 0.5), but no significant difference was found between GIII and GIV and between GV and GVI. Results showed that the deposition of collagen type I was higher when treatment with PRP and LLLT was combined, suggesting a faster regeneration of the tendon.

Use of platelet rich plasma in an isolated complete medial collateral ligament lesion in a professional football (soccer) player: a case report

Purpose

Platelet-rich plasma (PRP) is derived from centrifuging whole blood to obtain a high platelet concentration containing numerous growth factors. Despite its widespread use, there is still a lack of high-level evidence regarding randomized clinical trials assessing the efficacy of PRP in treating ligament injuries. Although there is research showing an improvement in the early stages of healing in the animal model of acute medial collateral ligament (MCL) injury of the knee, there is no strong evidence to support the efficacy of PRP injections for treating MCL lesions in humans.

Case Report

In this report, we present a case of an elite football player, treated with multiple PRP local injections followed by rehabilitation, for a high grade MCL lesion of the knee. He was able to resume training at day 18, painfree, with full range of motion and the ability to complete a functional test based on all sport specific movements. He played matches at 25 days with no residual symptoms or functional deficit. There were no further complaints or recurrences at the 16 months follow up.

Conclusions

On the basis of this report, we can assume that the treatment of high grade acute MCL lesions of the knee with PRP is a promising therapeutic option to be further explored with good quality Randomized Controlled Trials (RCTs).

Platelet-rich plasma therapy for knee joint problems: review of the literature, current practice and legal perspectives in Korea

Platelet-rich plasma (PRP) is a concentrate extract of platelets from autologous blood, and represents a possible treatment option for the stimulation and acceleration of soft-tissue healing and regeneration in orthopedics. Currently, the availability of devices for outpatient preparation and delivery contributes to the increase in the clinical use of PRP therapy in practical setting of orthopedic fields. However, there is still paucity of scientific evidence in the literature to prove efficacy of PRP therapy for the treatment of ligament or tendon problems around the knee joint. Moreover, strong evidence from well-designed clinical trials to support the PRP therapy for osteoarthritis of the knee joint is yet scanty in the literature. Scientific studies need to be performed to assess clinical indications, efficacy, and safety of PRP, and this will require high powered randomized controlled trials. Nonetheless, some hospitals exaggeratedly advertise PRP procedures as the ultimate treatment and a novel technology with abundant scientific evidence for the treatment of knee problems. As a matter of fact, PRP protocols are currently approved only for use in clinical trials and research, and are not allowed for treatment purpose by any institutions in Korea. At present, clinical use of PRP therapy for ligament or tendon problems or osteoarthritis of knee joint is defined as illegal medical practice, regardless of whether it is performed as a sole procedure or as a part of prolotherapy, because the safety and validity are not yet approved by the Ministry of Health and Welfare and Health Insurance Review and Assessment Service. Practicing physicians should remember that injection of PRP to patients by imposing medical charge is still illegal as per the current medical law in Korea.

Surgical reconstruction and mobilization therapy for a retracted extensor hallucis longus laceration and tendon defect repaired by split extensor hallucis longus tendon lengthening and dermal scaffold augmentation

A reconstructive technique and physical therapy protocol is presented for the treatment of extensor hallucis longus (EHL) lacerations with critical size defects caused by tendon retraction. The primary goal of treatment was to restore EHL structure and function without the use of a bridging allograft or tendon transfer. The technique is performed by split lengthening the distal segment of the lacerated EHL and rotating the lengthened segment proximally 180° to bridge the tendon defect. The lengthened tendon is then sutured to the proximal segment of the EHL. The EHL is then tubularized with an acellular dermal scaffold at the region of tendon rotation to improve tendon strength, minimize the probability of tendon overlengthening or re-rupture, and improve the tendon gliding motion, which can be compromised by the tendon irregularity caused by rotation of the tendon. Postoperative range of motion therapy should be initiated at 3 weeks postoperatively. A case report of this technique and postoperative mobilization protocol is presented. The American Orthopaedic Foot and Ankle Society midfoot score at 3 and 6 months postoperatively was 90 of 100. The patient regained active dorsiflexion motion of the hallux without functional limitations, deformity, or contracture of the hallux. The advantages of this technique include that a large cadaveric allograft is not needed to bridge a critical size tendon defect and tendon lengthening provides a biologically active tendon graft without the secondary comorbidities and dysfunction commonly associated with tendon transfer procedures.

Pain and activity levels before and after platelet-rich plasma injection treatment of patellar tendinopathy: a prospective cohort study and the influence of previous treatments

Purpose

The aim of this study was to evaluate the outcome of patients with patellar tendinopathy treated with platelet-rich plasma injections (PRP). Additionally, this study examined whether certain characteristics, such as activity level or previous treatment affected the results.

Methods

Patients (n = 36) were asked to fill in the Victorian Institute of Sports Assessment – Patellar questionnaire (VISA-P) and visual analogue scales (VAS), assessing pain in activities of daily life (ADL), during work and sports, before and after treatment with PRP. Of these patients, 14 had been treated before with cortisone, ethoxysclerol, and/or surgical treatment (group 1), while the remaining patients had not been treated before (group 2).

Results

Overall, group 1 and group 2 improved significantly on the VAS scales (p < .0.05). However, group 2 also improved on VISA-P (p = .0.003), while group 1 showed less healing potential (p = 0.060). Although the difference between group 1 and group 2 at follow-up was not considered clinically meaningful, over time both groups showed a clinically significant improvement.

Conclusion

After PRP treatment, patients with patellar tendinopathy showed a statistically significant improvement. In addition, these improvements can also be considered clinically meaningful. However, patients who were not treated before with ethoxysclerol, cortisone, and/or surgical treatment showed the improvement.

Platelet-rich plasma: a milieu of bioactive factors

Platelet concentrates such as platelet-rich plasma (PRP) have gained popularity in sports medicine and orthopaedics to promote accelerated physiologic healing and return to function. Each PRP product varies depending on patient factors and the system used to generate it. Blood from some patients may fail to make PRP, and most clinicians use PRP without performing cell counts on either the blood or the preparation to confirm that the solution is truly PRP. Components in this milieu have bioactive functions that affect musculoskeletal tissue regeneration and healing. Platelets are activated by collagen or other molecules and release growth factors from alpha granules. Additional substances are released from dense bodies and lysosomes. Soluble proteins also present in PRP function in hemostasis, whereas others serve as biomarkers of musculoskeletal injury. Electrolytes and soluble plasma hormones are required for cellular signaling and regulation. Leukocytes and erythrocytes are present in PRP and function in inflammation, immunity, and additional cellular signaling pathways. This article supports the emerging paradigm that more than just platelets are playing a role in clinical responses to PRP. Depending on the specific constituents of a PRP preparation, the clinical use can theoretically be matched to the pathology being treated in an effort to improve clinical efficacy.

Musculoskeletal diseases--tendon

INTRODUCTION

Tendons establish specific connections between muscles and the skeleton by transferring contraction forces from skeletal muscle to bone thereby allowing body movement. Tendon physiology and pathology are heavily dependent on mechanical stimuli. Tendon injuries clinically represent a serious and still unresolved problem since damaged tendon tissues heal very slowly and no surgical treatment can restore a damaged tendon to its normal structural integrity and mechanical strength. Understanding how mechanical stimuli regulate tendon tissue homeostasis and regeneration will improve the treatment of adult tendon injuries that still pose a great challenge in today's medicine.

SOURCE OF DATA

This review summarizes the current status of tendon treatment and discusses new directions from the point of view of cell-based therapy and regenerative medicine approach. We searched the available literature using PubMed for relevant original articles and reviews.

GROWING POINTS

Identification of tendon cell markers has enabled us to study precisely tendon healing and homeostasis. Clinically, tissue engineering for tendon injuries is an emerging technology comprising elements from the fields of cellular source, scaffold materials, growth factors/cytokines and gene delivering systems.

AREAS TIMELY FOR DEVELOPING RESEARCH

The clinical settings to establish appropriate microenvironment for injured tendons with the combination of these novel cellular- and molecular-based scaffolds will be critical for the treatment.