Follow-up on a Biological Revision Technique for Large, Recurrent, Retracted, Rotator Cuff Tears

INTRODUCTION

Revision of large recurrent rotator cuff tears by simple repair has a structural failure rate of 40% to 90%. The author presents a minimum 2-year follow-up study of revision rotator cuff reconstructions using a bridging patch graft composed of autogenous biceps tendon saturated with concentrated autologous iliac bone marrow, to determine how the technique compares to the reported outcome of simple repair as a treatment alternative.

METHODS

The principal entrance criterion was a symptomatic rotator cuff retear with retraction creating a 3- to 5-cm defect. Twenty-five consecutive patients (with an average age of 62 years) were enrolled. Twenty-two (88%) were available for follow-up at 24 to 120 months (mean 68 months) for interview and examination. Questionnaires using Constant, American Shoulder and Elbow Surgeons, and University of California at Los Angeles (UCLA) Shoulder scores were completed. In the terminal 15 patients, the presence of viable marrow mesenchymal cells fixed to the tendon graft at the time of implantation was determined by histological verification. Rotator cuff integrity was evaluated by ultrasonography examination. The Wilcoxon rank-sum test was used to compare nonparametric preoperative with postoperative questionnaire outcome scores.

RESULTS

Twenty of 22 patients (91%) demonstrated an intact tendon construct. Two of 22 patients (9%) demonstrated structural failure. Viable mesenchymal cells were identified on all graft specimens in high concentration. All patients showed improved results: The mean Constant score increased from 13 to 76; American Shoulder and Elbow Surgeons from 17 to 81; UCLA from 6 to 29 (P < 0.001).

DISCUSSION

The autogenous graft/marrow technique consistently and successfully reconstructed a large, recurrent rotator cuff tear in a clinical setting where the primary cuff repair had failed. The observation that an autogenous tendon graft saturated with concentrated marrow has the biological potential to reconstruct a difficult soft-tissue defect in the shoulder strongly implies its potential as a reconstructive tool for other soft-tissue defects.

Platelet-Rich Plasma for Knee Osteoarthritis: Internet Marketing and Patient Education-An Appraisal of Content for Websites with the Greatest Search Engine Visibility

OBJECTIVE

The internet is increasingly being used as a resource for health-related information by the general public. We sought to establish the authorship, content, and accuracy of the information available online regarding platelet-rich plasma (PRP) therapy for knee osteoarthritis.

DESIGN

Top 200 search results from each of the 3 leading search engines available online (Google, Yahoo!, Bing) were screened, and 181 websites were finally reviewed for content with emphasis on specific claims, comparing between websites authored by private physicians/groups and other authorship types.

RESULTS

Nearly 80% of the websites claimed that PRP injections for osteoarthritis of the knee improve patients' pain. A total of 42.8% of the private websites and 27.6% of nonprivate websites have stated that the procedure can delay or eliminate the need for future surgery. Costs were only mentioned by few (11.6%), and mainly by the nonprivate websites. Both website groups were unlikely to mention that PRP therapy is not the treatment of choice for end-stage knee osteoarthritis (7.9% of private and 17.2% of the nonprivate sites), or to state that patients with less advanced disease may benefit more from the treatment (11.8% and 20.6%, respectively). Private websites were less likely to refer to peer-reviewed literature (18.4% vs. 41.4%) and were more than 3 times less likely to mention lack of adequate evidence (13.2% vs. 48.2%).

CONCLUSIONS

Patients seeking online information regarding PRP therapy are vulnerable to websites presenting a narrow viewpoint of this treatment modality, putting emphasis on unsubstantiated benefits while disregarding potential drawbacks and concerns.

Intraarticular Platelet Rich Plasma vs Corticosteroid Injections for Sacroiliac Joint Pain-a Double Blinded, Randomized Clinical Trial

OBJECTIVE

Using stringent inclusion criteria, a double-blinded study protocol, and fluoroscopic guided injections, we compare intraarticular sacroiliac joint platelet rich plasma injections to intraarticular steroids.

DESIGN

Double-blind, randomized controlled trial.

SETTING

Two large university-based interdisciplinary spine centers.

SUBJECTS

26 patients after positive diagnostic block (>80% relief).

METHODS

Subjects who a positive diagnostic block were randomized to either undergo a fluoroscopically-guided intra-articular injection of steroid or platelet rich plasma injection. Follow-up was at 1-month, 3 months, and 6-months. Outcomes included level of pain as indicated on a 0- to 100-mm Numeric Pain Rating Scale and functional disability score using the Oswestry Disability Index (ODI).

RESULTS

At one, three, and six months, both groups improved, however subjects who received steroid injections reported lower pain scores than subjects who received platelet rich plasma. Using categorical data, we observed significantly more responders (defined as pain scores which improved by 50% or more from baseline) at one and three months in the group that received steroids compared to the group that received platelet rich plasma.

CONCLUSION

While both groups showed improvements in pain and function, the steroid group had significantly greater response and significantly more responders than the PRP group.

The Effect of a Single Freeze-Thaw Cycle on Matrix Metalloproteinases in Different Human Platelet-Rich Plasma Formulations

Storing platelet-rich plasma (PRP) for future use is a compelling approach, presuming the retention of biological properties is maintained. However, certain factors in PRP preparations have deleterious effects for the treatment of certain musculoskeletal conditions. The purpose of this study was to measure and compare matrix metalloproteinase protein (MMP) concentrations between fresh and freeze-thawed leukocyte-rich PRP (LR-PRP) inactivated (LR-I) and activated (LR-A) preparations, and leukocyte-poor PRP (LP-PRP) inactivated (LP-I) and activated (LP-A) preparations. A volume of 60 mL of whole blood was drawn from 19 healthy donors. LP-I and LR-I samples were processed using a manual extraction and centrifugation methodology. LP-A and LR-A products were activated with 10% CaCl2 and recombinant thrombin. Blood fractions were either immediately assayed and analyzed or stored at -80 °C for 24, 72 and 160 h. Multiplex immunoassay was used to measure MMP-1, MMP-2, MMP-3, MMP-9, MMP-10, and MMP-12. MMP-1 concentrations increased in LR-A (p < 0.05) and MMP-9 significantly increased in LR-I (p < 0.05), while MMP-2 significantly decreased in LR-I (p < 0.05) and MMP-3 concentrations significantly decreased in LR-A (p < 0.05). MMP-12 concentrations also significantly decreased in LR-I (p < 0.05) from baseline concentrations. There were no significant differences between LP-A and LP-I preparations and MMP concentrations. MMP-10 concentrations in all PRP samples compared to each freezing time point were also not significantly different. MMPs regulate components of the extracellular matrix (ECM) in the remodeling phase of musculoskeletal injury. In this study, we observed a significant increase and decrease in MMP concentrations in response to a single freeze-thaw cycle in inactivated PRP and activated PRP preparations. This evidence contributes to the growing body of literature on the optimization of PRP preparation and storage strategies prior to delivery. Our findings suggest that specific PRP preparations after a single freeze-thaw may be more advantageous for certain musculoskeletal applications based on the presence of MMP concentrations.

Autologous Platelet-Rich Plasma Efficacy in the Field of Regenerative Medicine: Product and Quality Control

Platelet-rich plasma (PRP) has emerged as a significant regenerative therapy used alone or combined mainly with stem cells, autologous fat grafts, hyaluronic acid, and biomaterials in a variety of medical fields, especially in hair regrowth, wound healing, and sports and rehabilitation medicine. However, the results obtained with this biologic therapy are heterogeneous and conflicting. The observed disparities in the effectiveness of PRP therapies may be due to a lack of standardization in blood processing and preparation. This article is aimed at reviewing the main biological parameters that need to be documented for a thorough reporting of quantitative and qualitative characteristics of the PRP injected, to allow a comparison between the quality of samples and the clinically obtained results and advance the efforts towards treatment standardization.

Platelet-Therapeutics to Improve Tissue Regeneration and Wound Healing-Physiological Background and Methods of Preparation

Besides their function in primary hemostasis, platelets are critically involved in the physiological steps leading to wound healing and tissue repair. For this purpose, platelets have a complex set of receptors allowing the recognition, binding, and manipulation of extracellular structures and the detection of pathogens and tissue damage. Intracellular vesicles contain a huge set of mediators that can be released to the extracellular space to coordinate the action of platelets as other cell types for tissue repair. Therapeutically, the most frequent use of platelets is the intravenous application of platelet concentrates in case of thrombocytopenia or thrombocytopathy. However, there is increasing evidence that the local application of platelet-rich concentrates and platelet-rich fibrin can improve wound healing and tissue repair in various settings in medicine and dentistry. For the therapeutic use of platelets in wound healing, several preparations are available in clinical practice. In the present study we discuss the physiology and the cellular mechanisms of platelets in hemostasis and wound repair, the methods used for the preparation of platelet-rich concentrates and platelet-rich fibrin, and highlight some examples of the therapeutic use in medicine and dentistry.

Age-based inter-subject variability in platelet and white blood cell concentrations of platelet-rich plasma prepared using a new application to blood separation system

The benefit of autologous platelet‐rich plasma (PRP) treatment is still under discussion. Variations in PRP products, consequence of the lack of a standardised protocol for the multitude of commercially available blood separation systems and the lack of knowledge of the optimal composition of PRP or its suitability for the proposed indication are some of the reasons behind clinical inconsistencies. The impact of inter‐subject variability in PRP has received less attention in comparison. The purpose of this study was to determine the inter‐subject variability, based on age, in the concentrates prepared by a new blood concentration system. Twenty‐six healthy volunteers of both genders (29‐93 years) were enrolled. Whole blood (WB) was collected from each participant to prepare PRP using the Easy PRP kit. Platelets and white blood cells (WBC) from WB and PRP were analysed after split population by age; patients younger than 65 years (n = 13) and patients ≥65 years old (n = 13). Among the demographic characteristics tested, only age was significantly different between the groups. Cell capture efficiency of the system was specific for each type of blood cell and identical for both age groups. Platelets and WBC in PRP were higher than in WB (P < .001). In WB, platelets and WBC concentrations were significantly lower in older group (P ≤ .035). These differences persisted in the prepared PRP (P ≤ .004). The ageing of population has a strong influence on the haematocrit and therefore on the composition of PRP. Because the efficiency of blood separator system seems to be constant across individuals, the inter‐subject haematocrit variability based on age could be used as a predictor of resulting PRP. The clinical application of PRP should be restricted to the specific cell capture capacity of the different commercial devices.

Effect of platelet-rich plasma on fracture healing

Bone has the ability to completely regenerate under normal healing conditions. Although fractures generally heal uneventfully, healing problems such as delayed union or nonunion still occur in approximately 10% of patients. Optimal healing potential involves an interplay of biomechanical and biological factors. Orthopedic implants are commonly used for providing the necessary biomechanical support. In situations where the biological factors that are needed for fracture healing are deemed inadequate, additional biological enhancement is needed. With platelets being packed with granules that contain growth factors and other proteins that have osteoinductive capacity, local application of platelet concentrates, also called platelet-rich plasma (PRP) seems an attractive biological to enhance fracture healing. This review shows an overview of the use PRP and its effect in enhancing fracture healing. PRP is extracted from the patient's own blood, supporting that its use is considered safe. Although PRP showed effective in some studies, other studies showed controversial results. Conflicts in the literature may be explained by the absence of consensus about the preparation of PRP, differences in platelet counts, low number of patients, and absence of a standard application technique. More studies addressing these issues are needed in order to determine the true effect of PRP on fracture healing.

Platelet-Rich Plasma: Evolving Role in Plastic Surgery

BACKGROUND

The use of platelet-rich plasma has emerged as one of the most desired nonsurgical treatments for facial rejuvenation and hair restoration. It has grown to encompass a wide variety of applications within the field of plastic surgery, including its use in combination with microneedling, laser, and fat-grafting procedures.

METHODS

In this article, the authors aim to (1) describe the preparation process of platelet-rich plasma; (2) discuss the proposed science behind platelet-rich plasma with regard to its evolving role in hair restoration and facial rejuvenation; and (3) highlight the recent literature examining its widespread use.

RESULTS

Based on the available literature, there is a therapeutic advantage to the use of platelet-rich plasma as a single treatment modality for alopecia and skin rejuvenation and in combination with laser skin treatment and fat grafting. There is, however, a considerable amount of variability in the processing, preparation, and treatment modalities.

CONCLUSIONS

Despite a lack of standardized protocols for platelet-rich plasma preparation and a scarcity of large-scale studies with long-term follow-up, there is convincing evidence with objective measurement modalities that display positive outcomes after treatment for skin rejuvenation, hair regrowth, wound healing, and fat graft take.

Recalcitrant lateral epicondylitis: Early results with a new technique combining ultrasonographic percutaneous tenotomy with platelet-rich plasma injection

PURPOSE

Surgical treatment of recalcitrant lateral epicondylitis [LE] remains difficult, with suboptimal results. This prospective study aimed to determine whether percutaneous epicondylar tenotomy combined with PRP injection under ultrasonography control would optimize the surgery results, with an early gain on pain and strength and a rapid return to professional activities at 3 months. The secondary objective was to determine whether clinical or biological risk factors (e.g., composition of the PRP) affected the outcomes.

METHODS

A total number of 261 Patients with recalcitrant LE underwent percutaneous epicondylar tenotomy under ultrasonography control, coupled with PRP injection. All patients were clinically assessed using VAS pain scale, the functional scores: QuickDASH [Disabilities of the Arm, Shoulder and Hand], Patient-Rated Tennis Elbow Evaluation [PRTEE] and MEPS [Mayo Elbow Performance Score]; Elbow Self-Assessment Score [ESAS]; grip strength; and return to work.

RESULTS

At 3-month follow-up, the VAS score decreased by 3.4 points (SD 2.2; p<0.0001), the QuickDASH decreased by 32.9 points (SD 18.9, range 56.1-23.1; p<0.0001), the PRTEE decreased by 14.8 points (SD 19.1, 49.8-26.4; p=0.017), and the MEPS increased by 19.4 points (SD 13.1, 67.4-86.9; p<0.0001); grip strength increased to 8.3kg (SD 10.7; p<0.0001) and increased by 26% (SD 0.60, 0.7-0.96; p<0.0001) as compared with the opposite side. The ESAS showed 78.3% improvement.

CONCLUSION

Treatment of recalcitrant LE by percutaneous tenotomy combined with PRP injection under ultrasonography control provides rapid recovery in terms of pain and strength, with a high level of satisfaction and a high rate of early return to work.

STUDY DESIGN

Case series.

Recovering from nonspecific low back pain despair: Ultrasound-guided intervention in iliolumbar syndrome

Background:

Iliolumbar syndrome is a frequent cause of chronic nonspecific low back pain. The cornerstone of its treatment lies upon the specific diagnosis of the iliolumbar syndrome. The ultrasound guided interventions have the potential for the specific diagnosis and treatment of the iliolumbar syndrome.

Objective:

To assess the role of ultrasound-guided intervention for the diagnosis and treatment of the iliolumbar syndrome.

Materials and Methods:

The study comprised of fifty-seven patients of nonspecific low back pain with the clinically suspected iliolumbar syndrome. Two-staged ultrasound-guided interventions were performed: Primary diagnostic and secondary therapeutic interventions. Favorable response after the injection of local anesthetic agent in iliolumbar ligament (defined as VAS score to ≥3) was classified as confirmed Ilio-lumbar syndrome. Clinico radiological efficacy after platelet-rich plasma (PRP) injection in confirmed iliolumbar syndrome patients was done.

Results:

Out of 57 patients, 45 (78.95%) were diagnosed with confirmed Iliolumbar syndrome after primary diagnostic intervention. The mean value of VAS at presentation was 8.02 ± 0.72 which was decreased to 3.16 ± 1.63; P < 0.0001. All 45 patients underwent PRP injection in iliolumbar ligament and 42 patients (93.33%) showed reduction in mean VAS score from 8 ± 0.67 (at presentation) to 0.89 ± 1.23 after 6 weeks follow up; P < 0.0001. Iliolumbar ligament thickness was decreased from the day of presentation (2.66 ± 0.22) to 6 weeks after therapeutic intervention (0.91 ± 0.42); P < 0.0001.

Conclusion:

The ultrasound guided diagnostic and therapeutic intervention were found to result in a specific diagnosis and remarkable recovery in the iliolumbar syndrome group of nonspecific low back pain patients.

Post-decellularization techniques ameliorate cartilage decellularization process for tissue engineering applications

Due to the current lack of innovative and effective therapeutic approaches, tissue engineering (TE) has attracted much attention during the last decades providing new hopes for the treatment of several degenerative disorders. Tissue engineering is a complex procedure, which includes processes of decellularization and recellularization of biological tissues or functionalization of artificial scaffolds by active cells. In this review, we have first discussed those conventional steps, which have led to great advancements during the last several years. Moreover, we have paid special attention to the new methods of post-decellularization that can significantly ameliorate the efficiency of decellularized cartilage extracellular matrix (ECM) for the treatment of osteoarthritis (OA). We propose a series of post-decellularization procedures to overcome the current shortcomings such as low mechanical strength and poor bioactivity to improve decellularized ECM scaffold towards much more efficient and higher integration.

Platelet-rich plasma and/or sildenafil topical applications accelerate and better repair wound healing in rats through regulation of proinflammatory cytokines and collagen/TGF-β1 pathway

Platelet-rich plasma (PRP) composites of various cytokines and growth factors which have the potential to activate and speed the process of wound repair. Sildenafil also is a potent stimulator of angiogenesis which favors its potential effects on wound healing in several models. Existing work planned to examine the effectiveness of topical application of PRP and/or sildenafil citrate hydrogel (SCH) in a non-splinted excision skin wound model. Adult male rats were allocated into control, PRP, SCH, and PRP/SCH groups. On the 7th and 14th days, blood and tissue samples were collected for hematobiochemical, histopathological, and immunohistochemistry analyses. PRP and/or SCH topical treatments caused an enhancement of wound healing parameters, including a rapid switch from inflammatory phase to connective tissue stage evident by less systemic hematological changes and decreased values of proinflammatory cytokines (IL-6, TNF-α, and IL-1β) and C-reactive protein (CRP) on the 7th or 14th days post-wounding. Also, tissue hydroxyproline, collagen, nitrite, and total protein contents were higher in therapeutically handled wounded rats. Histologically, PRP- and/or SCH-treated wounded rats exhibited less necrosis, inflammation, and fibrin with a higher level of granulation tissue formation on the 7th day post-wounding and abundant collagen remodeling, epithelization, and vascularization on the 14th day relative to control. Interestingly, combined PRP and SCH treatment was more efficient in wound healing scoring with less inflammation, more collagen remodeling, and more epithelization. Our findings confirm the effectiveness of PRP and/or SCH as a topical wound healing treatment, with better skin wound healing with their combination.

Preparation Methods and Clinical Outcomes of Platelet-Rich Plasma for Intra-articular Hip Disorders: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background:

Despite its increasing use in the management of musculoskeletal conditions, questions remain regarding the preparation methods of platelet-rich plasma (PRP) and its clinical applications for intra-articular hip disorders, including femoroacetabular impingement syndrome (FAIS), labral pathology, and osteoarthritis (OA).

Purpose:

To systematically review and assess the preparation methods and clinical outcomes from randomized clinical trials (RCTs) on the use of PRP for intra-articular hip disorders.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

A systematic review in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed in September 2019. The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, Ovid Medline, and Embase were queried for studies regarding the use of PRP to treat intra-articular hip disorders. Qualifying articles were English-language RCTs describing the use of PRP for intra-articular hip disorders, either as standalone treatment or surgical augmentation. Two authors independently assessed article eligibility. Data pertaining to patient characteristics, indication for treatment, PRP preparation method, follow-up period, and clinical outcomes were extracted. Study results were qualitatively reported and quantitatively compared using meta-analysis when appropriate.

Results:

Seven RCTs met inclusion criteria. Four studies described the use of PRP for hip OA and 3 utilized PRP at arthroscopy for FAIS and labral tears. Outcomes after PRP for OA demonstrated improvement in validated patient-reported outcome measures for up to 1 year; however, pooled effect sizes found no statistically significant difference between PRP and hyaluronic acid (HA) regarding pain visual analog scale scores at short-term (≤2 months; P = .27), midterm (4-6 months; P = .85), or long-term (1 year; P = .42) follow-up. When injected at arthroscopy, 1 study reported improved outcomes, 1 reported no difference in outcomes, and 1 reported worse outcomes compared with controls. The meta-analysis demonstrated no statistically significant difference on the modified Harris Hip Score (mHHS) between PRP and control cohorts at a minimum 1-year follow-up. There were considerable deficiencies and heterogeneity in the reporting of PRP preparation methods for both indications.

Conclusion:

Treatment of OA with PRP demonstrated reductions in pain and improved patient-reported outcomes for up to 1 year. However, there was no statistically significant difference between PRP and HA in pain reduction. Likewise, for FAIS and labral surgery there was no statistically significant difference in mHHS outcomes between patients treated with PRP and controls. Given the limited number of studies and variability in PRP preparations, additional high-quality randomized trials are warranted.

The Stryker Regenkit PRP Kit Does Not Concentrate Canine Platelets

Platelet Rich Plasma (PRP) works to recruit growth factors, anti-inflammatory mediators, and blood supply to an area that may not heal well under normal conditions (e.g., joints, tendons, ligaments). Previous research has demonstrated that various PRP systems create vastly different final products. The objective of this study was to evaluate the cellular composition of the final plasma product using the Stryker RegenKit system in dogs. A peripheral blood sample was obtained from ten healthy adult dogs and compared to the final plasma product. A standard CBC was performed prior to testing and an additional sample was processed according the manufacturing guidelines for obtaining PRP (10 ml total blood). Comparisons of mean platelet count, erythrocyte count, and leukocyte count were made between the peripheral blood sample and the final plasma product. Results showed that there was no significant difference in platelet count between the peripheral blood CBC and final PRP CBC (p = 0.349). There were significantly fewer erythrocytes and leukocytes in the final plasma product when compared with peripheral blood (p = < 0.0001, p = 0.0318, respectively). These results indicate that the Stryker Regenkit PRP Kit decreases leukocyte and erythrocyte concentrations but does not consistently change platelet concentrations in its final plasma product. This study, in combination with results from similar studies, may allow clinicians to better choose the appropriate PRP system to treat various musculoskeletal conditions in dogs.

Prospective Evaluation of Feline Sourced Platelet-Rich Plasma Using Centrifuge-Based Systems

Objective: To evaluate the hematologic components of platelet-rich plasma (PRP) generated using feline blood with two commercially available centrifuge-based systems^1,2.

Materials and methods: Twenty healthy adult cats were enrolled in this prospective study from November 2018 to January 2019. Feline blood samples were obtained for analysis of whole blood (WB) cellular components and preparation of PRP product. PRP was prepared using two commercial systems and complete blood count (CBC) testing was performed on both WB and PRP samples. The cellular composition of the PRP product was compared to the WB sample for each patient.

Results: Both systems showed significant decrease of median RBC concentration in PRP products compared to WB samples (P = 0.002 for both systems). System 1 significantly decreased median WBC concentration (P = 0.002). System 2 decreased WBC concentration, though statistical significance was not reached (P = 0.63). Median platelet concentration was decreased by 3% using System 1, and increased by 187% using System 2. Platelet aggregation presented a challenge with 8/20 (40%) of samples demonstrating platelet aggregation.

Clinical relevance: Commercial systems available for generation of PRP may be useful for creating a feline sourced product and in this study showed promise in decreasing RBC and WBC concentration. Neither system tested achieved 2–5 times platelet concentration from baseline. Platelet aggregation presented a significant obstacle to reliable generation of PRP products using feline blood. This treatment modality may be particularly beneficial for feline patients with osteoarthritis and soft tissue injuries, though first characterizing the PRP product made using feline blood is critical to validate its use in further clinical studies.

Nonoperative Treatments for Knee Osteoarthritis: An Evaluation of Treatment Characteristics and the Intra-Articular Placebo Effect: A Systematic Review

BACKGROUND

Guidelines recommending various nonoperative treatments for patients with knee osteoarthritis remain inconsistent. Much of this controversy relates to what constitutes a clinically important effect. The purposes of the present study were to compare treatment effect sizes from recent meta-analyses evaluating pharmacological or medical device interventions for the treatment of knee osteoarthritis and to further assess the clinical impact that the intra-articular placebo effect may have on intra-articular injection therapies.

METHODS

A search of PubMed, MEDLINE, and Embase from the inception date of each database through May 30, 2017 was conducted for all articles involving meta-analyses of pharmacological or medical device knee osteoarthritis treatments compared with controls. Two reviewers independently screened articles for eligibility and extracted data for analysis. We present effect estimates on a standardized mean difference (SMD) scale and compare them all against a threshold for clinical importance of 0.50 standard deviation (SD) unit.

RESULTS

Ten meta-analyses (sample size range, 110 to 39,814) providing a total of 19 different effect sizes for pain were included in this review. SMD estimates ranged from 0.08 to 0.79 for various electrical modalities, orthotic devices, topical and oral nonsteroidal anti-inflammatory drugs (NSAIDs), dietary supplements, and intra-articular injection therapies. Seventeen treatments demonstrated significant improvements in terms of pain when patients who had received treatment were compared with controls. After accounting for the intra-articular placebo effect, the greatest effect estimates were those of intra-articular platelet-rich plasma and high molecular weight hyaluronic acid. When these were judged according to our threshold for clinical importance, high molecular weight intra-articular hyaluronic acid was found to have the most precise effect estimate that surpassed this threshold. Platelet-rich plasma was found to provide the greatest point estimate of the treatment effect, but the precision around this estimate had the largest amount of uncertainty across all treatments.

CONCLUSIONS

While many nonoperative treatments demonstrated significant improvements in pain, we found the greatest effect estimates for intra-articular treatments. While platelet-rich plasma provided the greatest point estimate of the treatment effect, variability among studies suggests that future research into optimal formulations is required. The strongest current evidence supports clinically important and significant treatment effects with intra-articular hyaluronic acid formulations between 1,500 and >6,000 kDa.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

New method in treatment of post-operative air leakage with fresh frozen plasma

BACKGROUND

No consensus regarding the best post-operative treatment option for air leak has been established. In this study, we evaluate the use of intra-pleural fresh frozen plasma (FFP) as a promising treatment method.

METHODS

Treatment for a sustained air leak (3 days) was warranted in approximately 12% of the lung surgeries at our institution. Fifty-two patients were treated with FFP by application of 250 mL daily. The patients were divided into two cohorts: cohort 1 consisted of 35 patients undergoing anatomical lung resections and cohort 2 consisted of 17 patients after miscellaneous types of lung surgery. Successfulness of the procedure as well as the potential influential factors was evaluated statistically and validated by a bootstrapping. Area under receiver operating characteristic curve was used to establish a cut-off value of the predictor.

RESULTS

In the first cohort, air leakage was successfully treated in 28 (80%), while in seven (20%) it was still present after third treatment with FFP. The success rate in cohort 2 was 76.5%. The only covariate which appeared to remain significant in both cohorts was flow as displayed on the digital suction device prior to application of FFP. Flow ≤375 mL/min was indicative of successful aerostasis.

CONCLUSION

Intra-pleural instillation of FFP seems to be a feasible method for the treatment of post-operative air leakage. Although the optimum strategy regarding its application as well as its limitations is yet to be established, an absence of complications or undesirable events makes this (off label) method a safe and promising alternative to existing options.

Impact of Platelet-Rich Plasma Use on Pain in Orthopaedic Surgery: A Systematic Review and Meta-analysis

CONTEXT

Amid extensive debate, evidence surrounding the use of platelet-rich plasma (PRP) for musculoskeletal injuries has rapidly proliferated, and an overall assessment of efficacy of PRP across orthopaedic indications is required.

OBJECTIVES

(1) Does PRP improve patient-reported pain in musculoskeletal conditions? and (2) Do PRP characteristics influence its treatment effect?

DATA SOURCES

MEDLINE, EMBASE, Cochrane, CINAHL, SPORTDiscus, and Web of Science libraries were searched through February 8, 2017. Additional studies were identified from reviews, trial registries, and recent conferences.

STUDY SELECTION

All English-language randomized trials comparing platelet-rich therapy with a control in patients 18 years or older with musculoskeletal bone, cartilage, or soft tissue injuries treated either conservatively or surgically were included. Substudies of previously reported trials or abstracts and conference proceedings that lacked sufficient information to generate estimates of effect for the primary outcome were excluded.

STUDY DESIGN

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level 1.

DATA EXTRACTION

All data were reviewed and extracted independently by 3 reviewers. Agreement was high between reviewers with regard to included studies.

RESULTS

A total of 78 randomized controlled trials (5308 patients) were included. A standardized mean difference (SMD) of 0.5 was established as the minimum for a clinically significant reduction in pain. A reduction in pain was associated with PRP at 3 months (SMD, -0.34; 95% CI, -0.48 to -0.20) and sustained until 1 year (SMD, -0.60; 95% CI, -0.81 to -0.39). Low- to moderate-quality evidence supports a reduction in pain for lateral epicondylitis (SMD, -0.69; 95% CI, -1.15 to -0.23) and knee osteoarthritis (SMD, -0.91; 95% CI, -1.41 to -0.41) at 1 year. PRP characteristics did not influence results.

CONCLUSION

PRP leads to a reduction in pain; however, evidence for clinically significant efficacy is limited. Available evidence supports the use of PRP in the management of lateral epicondylitis as well as knee osteoarthritis.

Mesenchymal stem cells as adjuvant therapy for limb lengthening in achondroplasia

Staged leg lengthening allows achondroplastic dwarfs to reach nearly normal height, but it takes long periods of external fixation and it can be burdened by delayed unions. Between 2009 and 2013, eight achondroplastic dwarfs showed delayed unions in the callus formation during femoral lengthening stages in our institute. We performed in-situ injections of bone marrow-derived stem cell concentrates. Patients underwent monthly clinical and radiographic assessment for determination of the healing rate. All eight patients showed an improvement in the regenerated bone, with an average healing index of 23.1 days/cm (range: 18.7-23.8 days/cm). The complete recovery of the delayed consolidation took on an average of 5.2 months (range: 2-10 months). The use of cellular therapy in these patients could represent an innovative application.

Cellular Components and Growth Factor Content of Platelet-Rich Plasma With a Customizable Commercial System

BACKGROUND

Platelet-rich plasma (PRP) is an autologous orthobiologic treatment option for musculoskeletal conditions with favorable results in a limited number of high-quality clinical trials. Because different blood-processing methods result in PRP with varying cellular and growth factor content, it is critical that clinicians understand the content of the specific PRP being used in clinical practice. One adjustable system, the Angel System, has few independent laboratory reports on the specific composition of its PRP. The goal of this study was to quantify the cellular and growth factor composition of PRP produced by this system at its lowest hematocrit settings.

HYPOTHESIS

The authors hypothesized that the system would significantly concentrate platelets over baseline and, at the lowest hematocrit settings, would reduce leukocytes to produce leukocyte-poor PRP.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten healthy male volunteers donated 150 mL of whole blood for processing. Three separate processing cycles were performed for each sample at the 0%, 1%, and 2% hematocrit settings. The resultant PRP from each cycle was sent for complete blood counts and enzyme-linked immunosorbent assay to quantify the following growth factors: platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF).

RESULTS

The system consistently concentrated platelets 5-fold over baseline, with no significant differences among settings. Leukocytes were concentrated at all settings, between 2 and 5 times over baseline. The 0% and 1% settings had significantly lower leukocyte concentrations than the 2% setting. Lymphocytes made up >89% of the leukocyte differential, while neutrophils represented <11% of the differential at each setting. There was a significant increase in PDGF and bFGF, a significant decrease in IGF-1, and no change in VEGF, with no difference among settings.

CONCLUSION

The system consistently concentrated platelets 5 times but was unable to reduce leukocytes, therefore resulting in leukocyte-rich PRP at each setting tested. Leukocytes had a differential composition of >89% lymphocytes and <11% neutrophils. For all settings, PDGF and bFGF were concentrated; IGF-1 was reduced; and VEGF was not significantly different from baseline.

CLINICAL RELEVANCE

These data can serve to guide clinicians considering using this particular PRP system. It consistently yielded leukocyte-rich PRP with a lymphocyte-predominant/neutrophil-reduced profile. Further research is needed to better understand how to apply this specific PRP in clinical practice.

Introduction of New Technologies in Orthopaedic Surgery

The introduction of new devices, biologics, and combination products to the orthopaedic marketplace is increasing rapidly. The majority of these new technologies obtain clearance to market by demonstrating substantial equivalence to a predicate (previously approved device) according to the U.S. Food and Drug Administration (FDA) 510(k) process. Surgeons play a critical role in the introduction of new technologies to patients and must take a leadership role in promoting safe, efficacious, appropriate, and cost-effective care, especially for operative procedures. Surgeons should monitor and document their patients' clinical outcomes and adverse events when using new technology, to ensure that the new technology is performing as desired.

Critical-Size Bone Defects: Is There a Consensus for Diagnosis and Treatment?

There is a significant burden of disease associated with bone defects, and their management is challenging. These injuries have a profound clinical and economic impact, and outcomes are limited by high rates of complication and reoperation, as well as poor functional outcomes. There remains a lack of consensus around definitions, reliable models, and best practices for the surgical management of bone defects. The current state of the literature on bone defects is reviewed here, with a focus on defining critical-size bone defect, the use of the induced membrane technique, the role of biologics, and the management of infected bone defects.

Leukocyte depletion does not affect the in vitro healing ability of platelet rich plasma

The clinical use of platelet-rich plasma (PRP) containing or deprived of leukocytes remains a subject of debate and a controversial issue. It is not yet clear whether leukocyte content has a positive or negative effect on tissue healing processes. Several studies, conducted mainly in the orthopedic field, support the use of leukocyte-poor (LP) PRP, whereas other studies have not identified any significant differences between the use of LP and leukocyte-rich PRP. In the present study, the role of leukocytes contained in PRP was assessed to verify their in vitro effect on fibroblasts and endothelial cells, which have a leading role in the biological processes associated with wound healing (including angiogenesis and matrix remodeling). The original sample of PRP was divided into two aliquots, one of which remained unaltered, while the other was deprived of leukocytes. The two aliquots were used in in vitro tests in order to verify the effects of leukocytes on proliferation, wound healing and tube formation, and in molecular analyses of growth factor and enzyme content. The present results highlighted a substantial overlap between the two formulations. This may be explained by similar levels of growth factors (vascular endothelial growth factor, thrombospondin-1, interferon-γ, platelet-derived growth factor-BB, -AA and -B, tumor growth factor-β1, fibroblast growth factor 7 and tumor necrosis factor-α) and enzymes (gelatinases and plasminogen activators) in the two formulations. These results support the hypothesis that the ability of the PRP to affect the in vitro biological response of endothelial cells and fibroblasts does not rely on the presence of leukocytes.

Men and Women Differ in the Biochemical Composition of Platelet-Rich Plasma

BACKGROUND

Autologous platelet-rich plasma (PRP) is widely used for a variety of clinical applications. However, clinical outcome studies have not consistently shown positive effects. The composition of PRP differs based on many factors. An improved understanding of factors influencing the composition of PRP is important for the optimization of PRP use.

HYPOTHESIS

Age and sex influence the PRP composition in healthy patients.

STUDY DESIGN

Controlled laboratory study.

METHODS

Blood from 39 healthy patients was collected at a standardized time and processed into leukocyte-poor PRP within 1 hour of collection using the same laboratory centrifuge protocol and frozen for later analysis. Eleven female and 10 male patients were "young" (aged 18-30 years), while 8 male and 10 female patients were "older" (aged 45-60 years). Thawed PRP samples were assessed for cytokine and growth factor levels using a multiplex assay and enzyme-linked immunosorbent assay. The platelet count and high-sensitivity C-reactive protein levels were measured. Two-way analysis of variance determined age- and sex-based differences.

RESULTS

Platelet and high-sensitivity C-reactive protein concentrations were similar in PRP between the groups ( P = .234). Male patients had higher cytokine and growth factor levels in PRP compared with female patients for inflammatory cytokines such as interleukin-1 beta (IL-1β) (9.83 vs 7.71 pg/mL, respectively; P = .008) and tumor necrosis factor-alpha (TNF-α) (131.6 vs 110.5 pg/mL, respectively; P = .048); the anti-inflammatory IL-1 receptor antagonist protein (IRAP) (298.0 vs 218.0 pg/mL, respectively; P < .001); and growth factors such as fibroblast growth factor-basic (FGF-basic) (237.9 vs 194.0 pg/mL, respectively; P = .01), platelet-derived growth factor (PDGF-BB) (3296.2 vs 2579.3 pg/mL, respectively; P = .087), and transforming growth factor-beta 1 (TGF-β1) (118.8 vs 92.8 ng/mL, respectively; P = .002). Age- but not sex-related differences were observed for insulin-like growth factor-1 (IGF-1) ( P < .001). Age and sex interaction terms were not significant. While mean differences were significant, there was also substantial intragroup variability.

CONCLUSION

This study in healthy patients shows differences in the composition of PRP between men and women, with sex being a greater factor than age. There was also proteomic variability within the groups. These data support a personalized approach to PRP treatment and highlight the need for a greater understanding of the relationships between proteomic factors in PRP and clinical outcomes.

CLINICAL RELEVANCE

Variability in the proteomic profile of PRP may affect tissue and clinical responses to treatment. These data suggest that clinical studies should account for the composition of PRP used.

The Assessment of Quality, Accuracy, and Readability of Online Educational Resources for Platelet-Rich Plasma

PURPOSE

To critically evaluate the quality, accuracy, and readability of readily available Internet patient resources for platelet-rich plasma (PRP) as a treatment modality for musculoskeletal injuries.

METHODS

Using the 3 most commonly used Internet search engines (Google, Bing, Yahoo), the search term "platelet rich plasma" was entered, and the first 50 websites from each search were reviewed. The website's affiliation was identified. Quality was evaluated using 25-point criteria based on guidelines published by the American Academy of Orthopaedic Surgeons, and accuracy was assessed with a previously described 12-point grading system by 3 reviewers independently. Readability was evaluated using the Flesch-Kincaid (FK) grade score.

RESULTS

A total of 46 unique websites were identified and evaluated. The average quality and accuracy was 9.4 ± 3.4 (maximum 25) and 7.9 ± 2.3 (maximum 12), respectively. The average FK grade level was 12.6 ± 2.4, which is several grades higher than the recommended eighth-grade level for patient education material. Ninety-one percent (42/46) of websites were authored by physicians, and 9% (4/46) contained commercial bias. Mean quality was significantly greater in websites authored by health care providers (9.8 ± 3.1 vs 5.9 ± 4.7, P = .029) and in websites without commercial bias (9.9 ± 3.1 vs 4.5 ± 3.2, P = .002). Mean accuracy was significantly lower in websites authored by health care providers (7.6 ± 2.2 vs 11.0 ± 1.2, P = .004). Only 24% (11/46) reported that PRP remains an investigational treatment.

CONCLUSIONS

The accuracy and quality of online patient resources for PRP are poor, and the information overestimates the reading ability of the general population. Websites authored by health care providers had higher quality but lower accuracy. Additionally, the majority of websites do not identify PRP as an experimental treatment, which may fail to provide appropriate patient understanding and expectations.

CLINICAL RELEVANCE

Physicians should educate patients that many online patient resources have poor quality and accuracy and can be difficult to read.

Use of a Cyclooxygenase-2 Inhibitor Does Not Inhibit Platelet Activation or Growth Factor Release From Platelet-Rich Plasma

BACKGROUND

It remains unestablished whether use of cyclooxygenase (COX)-2 inhibitors impairs platelet activation and anabolic growth factor release from platelets in platelet-rich plasma (PRP).

PURPOSE

The purpose of this study was to assess the effects of a COX-2 inhibitor on platelet activation and anabolic growth factor release from canine PRP when using a clinically applicable PRP activator and to determine whether a 3-day washout would be sufficient to abrogate any COX-2 inhibitor-related impairment on platelet function.

STUDY DESIGN

Controlled laboratory study.

METHODS

Ten healthy dogs underwent blood collection and PRP preparation. Dogs were then administered a COX-2 inhibitor for 7 days, after which PRP preparation was repeated. The COX-2 inhibitor was continued for 4 more days and PRP preparation performed a third time, 3 days after discontinuation of the COX-2 inhibitor. Immediately after PRP preparation, the PRP was divided into 4 aliquots: 2 unactivated and 2 activated using human γ-thrombin (HGT). One activated and 1 unactivated sample were assessed using flow cytometry for platelet expression of CD62P and platelet-bound fibrinogen using the canine activated platelet-1 (CAP1) antibody. The 2 remaining samples were centrifuged and the supernatant assayed for transforming growth factor-β1 (TGF-β1), platelet-derived growth factor-BB (PDGF-BB), and thromboxane B2 (TXB2) concentrations. Differences in platelet activation and TGF-β1, PDGF-BB, and TXB2 concentrations over the 3 study weeks were evaluated using a 1-way repeated-measures ANOVA, and comparisons between activated and unactivated samples within a study week were assessed with paired t tests.

RESULTS

There were no statistically significant ( P > .05) effects of the COX-2 inhibitor on percentage of platelets positive for CD62P or CAP1 or on concentrations of TGF-β1, PDGF-BB, or TXB2. All unactivated samples had low levels of activation or growth factor concentrations and significantly ( P < .05) greater activation and growth factor concentrations in HGT-activated samples.

CONCLUSION

This COX-2 inhibitor did not impair platelet activation, growth factor release, or TXB2 production in this canine PRP when using HGT as an activator. Studies are warranted to determine whether COX-2 inhibitors affect platelet activation and growth factor release from human PRPs.

CLINICAL RELEVANCE

These results suggest that there is no need to withhold a COX-2 inhibitor before PRP preparation, particularly if thrombin is going to be used to activate the PRP. This is clinically relevant information because many patients who are candidates for PRP therapy for treatment of musculoskeletal injury are also using COX-2 inhibitors.

Advances in Aesthetic Therapies: Plasma-Rich Protein Procedure for the Treatment of Alopecia

Predominance of aesthetic options is growing and evolving to include procedures that have traditionally been much more invasive and fiscally challenging for the average patient. It is not uncommon now for the Canadian consumers to begin to look for lesser invasive options that show results significant enough to improve their appearance but that may not fall under the traditional health care coverage. One area that is evolving quickly is the nonsurgical treatment of hair loss. This is not a new condition, but generally the methods of treatment are not under the current health coverage; therefore, consumers are paying out of pocket to reduce or replace their hair loss. Recently, more options have evolved, and utilizing platelet-rich plasma has become more prevalent as a method to support hair growth and prevent hair loss.

Biologic Approaches to Problems of the Hand and Wrist

Orthobiologics are not used as frequently in the hand and wrist as in other sites. The most frequently reported is the use of bone morphogenetic protein for the treatment of Kienböck disease. Animal studies have described improved tendon healing with the use of platelet-rich plasma (PRP), but no clinical studies have confirmed these results. PRP has been reported to produce improvements in the outcomes of distal radial fractures and osteoarthritis of the trapeziometacarpal in small numbers of patients. The use of orthobiologics in the hand and wrist are promising, but clinical trials are necessary to establish efficacy and safety.

Platelet-Rich Plasma Augmentation for Hip Arthroscopy

Biological augmentation and therapeutics are being increasingly used in musculoskeletal and orthopaedic care. Platelet-rich plasma (PRP) is produced from centrifugation of peripheral blood, a process that concentrates platelets within autologous plasma. The process of PRP preparation is fundamental in controlling the contents, and it influences its therapeutic potential. Platelets contain alpha granules that store and release a variety of growth factors and other proteins that may augment the healing environment; PRP also has the added benefit of promoting postsurgical hemostasis. The purpose of this report was to detail our institutional preparation protocol and method of administration of PRP during hip arthroscopy.

Commercial Separation Systems Designed for Preparation of Platelet-Rich Plasma Yield Differences in Cellular Composition

BACKGROUND

The role of platelet-rich plasma (PRP) in the treatment of sport-related injuries is unclear, largely due to the heterogeneity of clinical results. This may relate to compositional differences in PRP from different separation systems.

QUESTIONS/PURPOSES

This study aims to compare the composition of PRP produced with five different commercially available systems, focusing on cellular concentrations and pH.

METHODS

Seven donors (41 ± 12 years) provided blood for PRP preparation using five systems (Arthrex Angel, Emcyte Genesis CS, Arteriocyte Magellan, Harvest SmartPrep, and Biomet GPS III). Post processing, cellular composition was measured including platelets (PLT), white blood cells (WBC), neutrophils (NE), and red blood cells (RBC), as well as pH.

RESULTS

Platelet concentration and capture efficiency were similar between systems, except the Angel 7% preparation had a greater concentration than Genesis CS (2310 ± 524 vs. 1129 ± 264 k/μL). WBC concentration was variable between systems; however, significant differences were only found between the Angel 2% and GPS III preparations (11.0 ± 4.5, 27.3 ± 7.1 k/μL). NE concentration was significantly lower in the Angel 2% and 7% preparations compared with GPS III (0.6 ± 0.6 and 1.8 ± 1.3 k/μL vs. 9.4 ± 7.0 k/μL). RBC concentration was highest in SmartPrep (3.2 ± 0.6 M/μL) and Genesis CS systems (3.1 ± 0.6 M/μL) compared with all other systems (≤1.1 ± 1.2 M/μL). Finally, pH was significantly lower with the SmartPrep system (6.95 ± 0.06) compared with all others (≥7.26 ± 0.06).

CONCLUSION

Aside from platelet concentration and capture efficiency, significant compositional differences were identified between preparation systems. Caution should be employed when interpreting clinical results of studies utilizing PRP, as the role of compositional differences and their effect on outcome are unknown. Further study is necessary to determine the clinical significance of these differences.

The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials

Background

Quite a few randomized controlled trials (RCTs) investigating the efficacy of platelet-rich plasma (PRP) for treatment of knee osteoarthritis (OA) have been recently published. Therefore, an updated systematic review was performed to evaluate the temporal effect of PRP on knee pain and physical function.

Methods

Pubmed, Embase, Cochrane library, and Scopus were searched for human RCTs comparing the efficacy and/or safety of PRP infiltration with other intra-articular injections. A descriptive summary and quality assessment were performed for all the studies finally included for analysis. For studies reporting outcomes concerning Western Ontario and McMaster Universities Arthritis Index (WOMAC) or adverse events, a random-effects model was used for data synthesis.

Results

Fourteen RCTs comprising 1423 participants were included. The control included saline placebo, HA, ozone, and corticosteroids. The follow-up ranged from 12 weeks to 12 months. Risk of bias assessment showed that 4 studies were considered as moderate risk of bias and 10 as high risk of bias. Compared with control, PRP injections significantly reduced WOMAC pain subscores at 3, 6, and 12 months follow-up (p = 0.02, 0.004, <0.001, respectively); PRP significantly improved WOMAC physical function subscores at 3, 6, and 12 months (p = 0.002, 0.01, <0.001, respectively); PRP also significantly improved total WOMAC scores at 3, 6 and 12 months (all p < 0.001); nonetheless, PRP did not significantly increased the risk of post-injection adverse events (RR, 1.40 [95% CI, 0.80 to 2.45], I² = 59%, p = 0.24).

Conclusions

Intra-articular PRP injections probably are more efficacious in the treatment of knee OA in terms of pain relief and self-reported function improvement at 3, 6 and 12 months follow-up, compared with other injections, including saline placebo, HA, ozone, and corticosteroids.

Review registration

PROSPERO CRD42016045410. Registered 8 August 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-017-0521-3) contains supplementary material, which is available to authorized users.

Short term storage stability at room temperature of two different platelet-rich plasma preparations from equine donors and potential impact on growth factor concentrations

Background

The increasing interest in platelet-rich plasma (PRP) based therapies is as yet accompanied by inconsistent information regarding nearly all aspects of handling and application. Among these storage stability of processed platelet-rich products may be the basis for a more flexible application mode. The objective of this study was (1) to estimate the storage stability of growth factors platelet derived growth factor BB (PDGF-BB) and transforming growth factor ß1 (TGF-ß1) in both, a single-step softspin centrifugation-based pure-PRP (P-PRP, ACP®), and a gravity filtration system-based leukocyte-rich-PRP (L-PRP, E-PET), over a six hours time span after preparation at room temperature and (2) to identify possible factors influencing these growth factor concentrations in an equine model.

Results

Growth factor concentrations remained stable over the entire investigation period in L-PRP as well as P-PRP preparations revealing a mean of 3569 pg/ml PDGF-BB for E-PET and means of 1276 pg/ml PDGF-BB and 5086 pg/ml TGF-ß1 for ACP®. Pearson correlations yielded no significant impact of whole blood platelet (PLT), white blood cell (WBC) and red blood cell (RBC) counts on resulting cytokine values. In case of ACP® no significant dependencies between PLT, WBC and RBC counts of the processed platelet-rich product and resulting cytokine content occurred with exception of TGF-ß1 concentrations showing a strong correlation with the WBC content. PDGF-BB content of E-PET preparations showed a strong positive correlation with PLT and a strong negative with WBC of these preparations but not with RBC.

Conclusions

L-PRP ad modum E-PET and P-PRP ad modum ACP® are applicable over at least a six hours time span at room temperature without loss of growth factor content. Based on the results of this study factors influencing the resulting growth factor concentrations still remain questionable. Additional studies implicating a further standardization of preparation protocols are necessary to identify consistent impact on cytokine content after PRP processing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0920-4) contains supplementary material, which is available to authorized users.

Platelet-Rich Plasma Activates Proinflammatory Signaling Pathways and Induces Oxidative Stress in Tendon Fibroblasts

BACKGROUND

Tendon injuries are one of the most common musculoskeletal conditions in active patients. Platelet-rich plasma (PRP) has shown some promise in the treatment of tendon disorders, but little is known as to the mechanisms by which PRP can improve tendon regeneration. PRP contains numerous different growth factors and cytokines that activate various cellular signaling cascades, but it has been difficult to determine precisely which signaling pathways and cellular responses are activated after PRP treatment. Additionally, macrophages play an important role in modulating tendon regeneration, but the influence of PRP on determining whether macrophages assume a proinflammatory or anti-inflammatory phenotype remains unknown.

PURPOSE

To use genome-wide expression profiling, bioinformatics, and protein analysis to determine the cellular pathways activated in fibroblasts treated with PRP. The effect of PRP on macrophage polarization was also evaluated.

STUDY DESIGN

Controlled laboratory study.

METHODS

Tendon fibroblasts or macrophages from rats were cultured and treated with either platelet-poor plasma (PPP) or PRP. RNA or protein was isolated from cells and analyzed using microarrays, quantitative polymerase chain reaction, immunoblotting, or bioinformatics techniques.

RESULTS

Pathway analysis determined that the most highly induced signaling pathways in PRP-treated tendon fibroblasts were TNFα and NFκB pathways. PRP also downregulated the expression of extracellular matrix genes and induced the expression of autophagy-related genes and reactive oxygen species (ROS) genes and protein markers in tendon fibroblasts. PRP failed to have a major effect on markers of macrophage polarization.

CONCLUSION

PRP induces an inflammatory response in tendon fibroblasts, which leads to the formation of ROS and the activation of oxidative stress pathways. PRP does not appear to significantly modulate macrophage polarization.

CLINICAL RELEVANCE

PRP might act by inducing a transient inflammatory event, which could then trigger a tissue regeneration response.

Biological Therapies for Cartilage Lesions in the Hip: A New Horizon

Treatment of hip cartilage disease is challenging, and there is no clear algorithm to address this entity. Biomarkers are arising as promising diagnostic tools because they could play a role in the early assessment of the prearthritic joint and as a prognostic factor before and after treatment. The potential effect of biomarkers may be used to categorize individuals at risk of evolving to severe osteoarthritis, to develop new measures for clinical progression of the disease, and to develop new treatment options for the prevention of osteoarthritis progression. A trend toward a less invasive biological treatment will usher in a new treatment era. With the growth of surgical skills in hip arthroscopy, cartilage restoration techniques are evolving in a fast and exponential manner. Biological and surgical treatments have been proposed to treat these pathologies. Biological treatments include platelet-rich plasma, stem cells or bone marrow aspirate concentration, hyaluronic acid, losartan, and fish oil. Surgical treatments include microfracture alone or augmented, direct repair, autologous chondrocyte implantation, matrix-induced chondrocyte implantation, autologous matrix-induced chondrogenesis, mosaicplasty, osteochondral allograft transplantation, and stem cells implanted in matrix (stem cells in membranes/expanded stem cells). This article reviews new evidence available on treatment options for chondral lesions and early osteoarthritis of the hip. [Orthopedics. 2016; 39(4):e715-e723.].

The Cost-Effectiveness of Using Platelet-Rich Plasma During Rotator Cuff Repair: A Markov Model Analysis

PURPOSE

To perform a cost-utility analysis to determine if the use of platelet-rich plasma (PRP) products during arthroscopic rotator cuff repair (RCR) is cost-effective.

METHODS

A cost-utility analysis was conducted using a Markov decision model. Model inputs including health utility values, retear rates, and transition probabilities were derived from the best evidence available in the literature regarding full-thickness rotator cuff tears and their repair, as well as the augmentation of their repair with PRP. Costs were determined by examining the typical patient undergoing treatment for a full-thickness rotator cuff tear in a private orthopaedic clinic and outpatient surgery center.

RESULTS

The cost per quality-adjusted life-year ($/QALY) of RCR with and without PRP was $6,775/QALY and $6,612/QALY, respectively. In our base case, the use of PRP to augment RCR was not cost-effective because it had exactly the same "effectiveness" as RCR without PRP augmentation while being associated with a higher cost (additional $750). Sensitivity analysis showed that to achieve a willingness-to-pay threshold of $50,000/QALY, the addition of PRP would need to be associated with a 9.1% reduction in retear rates. If the cost of PRP were increased to $1,000, the retear rate would need to be reduced by 12.1% to reach this same threshold. This compared with a necessary reduction of only 6.1% if the additional cost of PRP was $500.

CONCLUSIONS

This cost-utility analysis shows that, currently, the use of PRP to augment RCR is not cost-effective. Sensitivity analysis showed that PRP-augmented repairs would have to show a reduced retear rate of at least 9.1% before the additional cost would be considered cost-effective.

LEVEL OF EVIDENCE

Level III, analysis of Level I, II, and III studies.

A Novel Technique to Treat Air Leak Following Lobectomy: Intrapleural Infusion of Plasma

Background

Persistent air leak following pulmonary lobectomy can be very difficult to treat and results in prolonged hospitalization. We aimed to evaluate the efficacy of a new method of postoperative air leak management using intrapleurally infused fresh frozen plasma via the chest tube.

Material/Methods

Between June 2008 and June 2014, we retrospectively reviewed 98 consecutive patients who underwent lobectomy for lung cancer and postoperatively developed persistent air leak treated with intrapleural instillation of fresh frozen plasma.

Results

The study identified 89 men and 9 women, with a median age of 65.5 years (range 48–77 years), with persistent postoperative air leak. Intrapleural infusion of fresh frozen plasma was successful in stopping air leaks in 90 patients (92%) within 24 hours, and in 96 patients (98%) within 48 hours, following resumption of the procedure. In the remaining 2, air leak ceased at 14 and 19 days.

Conclusions

Intrapleural infusion of fresh frozen plasma is a safe, inexpensive, and remarkably effective method for treatment of persistent air leak following lobectomy for lung cancer.

Multiple injections of leukoreduced platelet rich plasma reduce pain and functional impairment in a canine model of ACL and meniscal deficiency

Platelet rich plasma (PRP) is used to treat many musculoskeletal disorders. We used a canine model to determine the effects of multiple intra-articular injections of leukoreduced PRP (ACP) on anterior cruciate ligament healing, meniscal healing, and progression of osteoarthritis (OA). With Animal Care and Use Committee (ACUC) approval, 12 dogs underwent partial ACL transection and meniscal release in one knee. At weeks 1, 2, 3, 6, and 8 after insult, dogs were treated with intra-articular injections (2 ml) of either ACP (n = 6) or saline (n = 6). Dogs were assessed over 6 months to determine comfortable range of motion (CROM), lameness, pain, effusion, kinetics, and radiographic and arthroscopic assessments. At 6-month endpoint, dogs were assessed for ACL material properties and histopathology. Saline-treated dogs had significantly (p < 0.04) more CROM loss, significantly (p < 0.01) more pain, significantly (p < 0.05) more severe lameness, significantly (p < 0.05) lower function, and significantly (p < 0.05) lower %Total Pressure Index in affected hindlimbs compared to ACP-treated dogs. Radiographic OA increased significantly (p < 0.01) over time within each group. Arthroscopically, saline-treated knees showed moderate to severe synovitis, further ACL disruption, and medial compartment cartilage loss, and ACP-treated knees showed evidence of ACL repair and less severe synovitis. ACL material properties in ACP-treated knees were closer to normal than in saline-treated knees, however, the differences were not statistically significant. ACL histopathology was significantly (p< 0.05) less severe in ACP-treated knees compared to saline-treated knees. Five intra-articular injections of leukoreduced PRP had beneficial effects for ACL healing, improved range of motion, decreased pain, and improved limb function for up to 6 months in this model.

Effect of Leukocyte Concentration on the Efficacy of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis

BACKGROUND

Leukocyte-poor platelet-rich plasma (LP-PRP) is hypothesized to be more suitable for intra-articular injection than leukocyte-rich PRP (LR-PRP) in the treatment of knee osteoarthritis.

PURPOSE

To compare clinical outcomes and rates of adverse reactions between LP-PRP and LR-PRP for this application.

STUDY DESIGN

Meta-analysis.

METHODS

The MEDLINE, EMBASE, and Cochrane databases were reviewed. The primary outcome was the incidence of local adverse reactions. Secondary outcomes were the changes in International Knee Documentation Committee (IKDC) subjective score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between baseline and final follow-up measurements. A Bayesian network meta-analysis was performed, with a post hoc meta-regression to correct for baseline differences in WOMAC scores. Treatment rankings were based on surface under the cumulative ranking (SUCRA) probabilities.

RESULTS

Included in the analysis were 6 randomized controlled trials (evidence level 1) and 3 prospective comparative studies (evidence level 2) with a total of 1055 patients. Injection of LP-PRP resulted in significantly better WOMAC scores than did injection of hyaluronic acid (mean difference, -21.14; 95% CI, -39.63 to -2.65) or placebo (mean difference, -17.84; 95% CI, -34.95 to -0.73). No such difference was observed with LR-PRP (mean difference, -14.28; 95% CI, -44.80 to 16.25). All treatment groups resulted in equivalent IKDC subjective scores. The SUCRA analysis showed that LP-PRP was the highest ranked treatment for both measures of clinical efficacy (WOMAC and IKDC). Finally, PRP injections resulted in a higher incidence of adverse reactions than hyaluronic acid (odds ratio, 5.63; 95% CI, 1.38-22.90), but there was no difference between LR-PRP and LP-PRP (odds ratio, 0.78; 95% CI, 0.05-11.93). These reactions were nearly always local swelling and pain, with a single study reporting medical side effects including syncope, dizziness, headache, gastritis, and tachycardia (17/1055 total patients).

CONCLUSION

LP-PRP results in improved functional outcome scores compared with hyaluronic acid and placebo when used for treatment of knee osteoarthritis. LP-PRP and LR-PRP have similar safety profiles, although both induce more transient reactions than does hyaluronic acid. Adverse reactions to PRP may not be directly related to leukocyte concentration.

Platelet-rich plasma versus open surgical release in chronic tennis elbow: A retrospective comparative study

PURPOSE

To compare short and mid-term results in the treatment of chronic elbow tendinosis with platelet-rich plasma (PRP) or Nirschl surgical technique.

METHOD

A retrospective study was conducted on patients with chronic lateral epicondylitis, treated by Nirschl surgical technique (50 elbows) or PRP (60 elbows). Outcome was evaluated with Visual Analog Score (VAS), Mayo Elbow Scores and grip strength measurements.

RESULTS

VAS and Mayo Elbow Scores of the PRP group had improved as a mean of 83% (p = 0.0001), 74% (p = 0.0001) over baseline and 34.2 pounds gain of grip strength.

CONCLUSION

The PRP seems to be better for pain relief and functionality in the short and mid-term periods.