Increased neutrophil-derived IL-17A identified in generalized pustular psoriasis.

Generalized pustular psoriasis (GPP) is considered to be a distinct clinical entity from psoriasis vulgaris (PV), with different clinical and histological manifestations. The pathogenesis of GPP has not been thoroughly elucidated, especially in those patients lacking interleukin (IL)36RN. In present study, we performed RNA sequence analysis on skin lesions from 10 GPP patients (4 with and 6 without IL36RN mutation) and 10 PV patients without IL36RN mutation. Compared with PV, significantly overexpressed genes in GPP patients were enriched in IL-17 signalling pathway (MMP1, MMP3, DEFB4A and DEFB4B, etc.) and associated with neutrophil infiltration (MMP1, MMP3, ANXA and SERPINB, etc.). GPP with IL36RN mutations evidenced WNT11 upregulation and IL36RN downregulation in comparison to those GPP without IL36RN mutations. The expression of IL-17A/IL-36 in skin or serum and the origin of IL-17A in skin were also investigated. IL-17A expression in skin was significantly higher in GPP than PV patients, whereas, there were no differences in skin IL-36α/IL-36γ/IL-36RA or serum IL-17A/IL-36α/IL-36γ between GPP than PV. Besides, double immunofluorescence staining of MPO/IL-17A or CD3/IL-17A further confirmed that the majority of IL-17A in GPP skin was derived from neutrophils, but not T cells. These data emphasized the role of neutrophil-derived IL-17A in the pathogenesis of GPP with or without IL36RN mutations. Targeting neutrophil-derived IL-17A might be a promising treatment for GPP.

Tranexamic acid use in arthroscopic rotator cuff repair is an effective and safe adjunct to improve visualization: a systematic review and meta-analysis.

PURPOSE: Although tranexamic acid (TXA) is being increasingly used in orthopedic arthroplasty and lower-extremity arthroscopic procedures, its use in arthroscopic rotator cuff repair (ARCR) is less widely reported. The aim of this study was to evaluate the clinical effectiveness and safety of TXA administration in ARCR. METHODS: A systematic review and meta-analysis of randomized controlled trials was performed to compare clinical outcomes in patients who underwent ARCR with or without TXA. Literature was retrieved using the Cochrane Library, MEDLINE, PubMed, and Embase electronic databases. The primary outcome of this study was visual clarity. Secondary outcomes contained total operative time, postoperative pain score, amount of blood loss, shoulder swelling (change in shoulder circumference), volume of irrigation fluid, number of adjustments of the pump pressure for irrigation, and adverse cardiovascular events. RESULTS: Seven studies (3 and 4 with level I and II evidence, respectively), which included 272 and 265 patients who underwent arthroscopy with and without TXA, respectively, met the eligibility criteria. Pooled analysis showed significant improvements in visual clarity (mean difference, 9.10%; 95% CI, 4.05-14.15; P = .0004) and total operative time (mean difference, -11.24 minute; 95% CI, -19.90 to -2.57) associated with perioperative TXA application. None of the trials reported adverse events and complications associated with TXA. CONCLUSION: The best available evidence indicates that TXA administration could significantly improve arthroscopic visual clarity and effectively save operative time in ARCR without increasing the incidence of adverse events. Furthermore, the optimal dose, route, and timing of TXA application in ARCR surgery remains to be validated by future high-level evidence studies.

Efficacy of platelet-rich plasma injections for treating Achilles tendonitis : Systematic review of high-quality randomized controlled trials.

BACKGROUND: The Achilles tendon is the coarsest tendon in the body. Achilles tendonitis is relatively common and its incidence is increasing. PURPOSE: To evaluate the efficacy of platelet-rich plasma (PRP) injections for treating Achilles tendonitis. METHODS: A literature search was carried out in the Cochrane Library Central Register of Controlled Trials (2017), PubMed (January 1976-March 2017) and EMBASE (January 1976-March 2017) databases to retrieve the available clinical evidence for PRP in the treatment of Achilles tendon lesions for a systematic review. The inclusion criteria were (1) conservative PRP treatment of Achilles tendon inflammation in a randomized controlled trial (RCT), (2) level I clinical research evidence and (3) published in English. The exclusion criteria were (1) unclear experimental methods and data and (2) PRP treatment of other diseases. RESULTS: A total of 4 articles involving 152 cases were included in the analysis. The mean age of subjects was 49 years. Data on the Victorian Institute of Sport Assessment-Achilles (VISA-A) score, color Doppler ultrasound index and recovery time to normal exercise were extracted. There were no significant differences between the treatment groups and control groups following the PRP injections. CONCLUSION: The lack of differences between data from the control group and the patient groups included in the studies may be related to the difficulty of performing a randomized controlled trial (RCT). A strong basis for using PRP to treat Achilles tendonitis was not found, although PRP has important clinical significance for treating Achilles tendonitis.

The effective mode of growth and differentiation factor-5 in promoting the chondrogenic differentiation of adipose-derived stromal cells.

Our study aimed to find out the most effective mode for chondrogenic differentiation based on time, dose and culture method. ADSCs were cultured and identified by CD44, CD49d, and CD106 immumohistochemical staining method, and their differentiation potential to chondrocyte were detected by Alizarin red staining. ADSCs induced by different concentrations of GDF-5 for chondrogenic differentiation were detected by blue and toluidine blue staining and collagen type II and X immumohistochemical staining. The expression of collagen I, II, X and aggrecan gene in GDF-induced ADSCs cultured in 2- and 3-dimension was identified by real-time PCR. Cell microstructure and proliferation in three-dimensional scaffolds at day 7, 14, 21 and 28 were analyzed by scanning electron microscopy and MTS assay. The ADSCs were successfully identified by CD44 and CD49d, and their differentiation potential was detected by Alizarin red staining. Real-time PCR showed that collagen and aggrecan were expressed at high levels in 100 or 200 ng/mL GDF-5 treated cells. The collagen types (I, II) and aggrecan genes were higher expressed in GDF-5 induced scaffold group than that in monolayer group. MTS showed that the cell counts were not significantly different among different treated time. Both collagen type II and aggrecan gene were highly expressed at day 14, while collagen types I and X gene expressions peaked at day 21 and 28. The 100 ng/mL GDF-5 is effective and cost-effective for chondrogenic differentiation when cultured at day 14 in vitro under three-dimensional culture conditions.

Identification of genes associated with the differentiation potential of adipose-derived stem cells to osteocytes or myocytes.

Adipose-derived stem cells (ADSCs) have been considered as the optimal cells for regenerative medicine because ADSCs have the potential of multi-directional differentiation. To study the mechanisms of ADSCs differentiation, we analyzed microarray of GSE37329. GSE37329 was downloaded from Gene Expression Omnibus including 3 ADSCs, 2 ADSCs-derived osteocytes, and 2 ADSCs-derived myocytes samples. The differentially expressed genes (DEGs) were screened using limma package. Their underlying functions were predicted by gene ontology and pathway enrichment analyses. Besides, the interaction relationships of the proteins encoded by DEGs were obtained from STRING database, and protein-protein interaction (PPI) network was constructed using Cytoscape. Furthermore, modules analysis of PPI network was performed using MCODE in Cytoscape. We screened 662 and 484 DEG separately for the ADSCs-derived osteocytes and myocytes compared with ADSCs. There were 205 common up-regulated and 128 common down-regulated DEGs between the two groups. Function enrichment indicated that these common DEGs, especially, VEGFA, FGF2, and EGR1 may be related to cell differentiation. PPI network for common DEGs also suggested that VEGFA (degree = 29), FGF2 (degree = 17), and EGR1 (degree = 12) might be more important because they had higher connectivity degrees, and they might be involved in cell differentiation by interacting with other genes in module A (e.g., EGR1-NGF and EGR1-LEP), and B (e.g., VEGFA-PDGFD). Additionally, the IGF1 and BTG1 may be, respectively, specific for osteocytes and myocytes differentiation. VEGFA, PDGFD, FGF2, EGR1, NGF, LEP, IGF1, and BTG1 might serve as target genes in regulating ADSCs differentiation.

Arthroscopic Lateral Meniscus Root Repair With Reverse Suture Anchor Technique.

The stability of the knee joint is crucially dependent on the integrity of the lateral meniscus posterior root, which is often accompanied by anterior cruciate ligament injury. Anchor suture repair for lateral meniscus posterior root injury not only achieves better biomechanical effects but also ensures favorable prognosis. However, the placement of anchors often requires the establishment of a posterior approach, and the insertion of an anchor is a technical challenge. In light of this, we have applied the technique of reverse anchor fixation for repairing the lateral meniscus posterior root, which not only simplifies the procedure but also effectively reduces the "bungee effect."

A Reverse Suture Anchor Technique for Arthroscopic Medial Meniscus Root Repair.

Injuries of the posterior root of the medial meniscus can be accompanied by damage to the anterior cruciate ligament or often occur independently in cases of degenerative meniscal injury in older individuals. Anchor suture repair can achieve favorable biomechanical effects and clinical outcomes. However, anchor placement is technically challenging and requires a posterior medial approach, which increases the risk of iatrogenic injury. To address these issues, we have utilized the reverse anchor technique to repair the posterior root of the medial meniscus. This technique offers advantages such as reduced surgical time, simplified operation, and reduced risk of the "bungee effect" and iatrogenic injury.

Exosomal miR-429 derived from adipose-derived stem cells ameliorated chondral injury in osteoarthritis via autophagy by targeting FEZ2.

BACKGROUND: Osteoarthritis (OA) is the most prevalent musculoskeletal disease, imposing a significant public health burden. Exosomes might be an effective means of treating OA. PURPOSE: To investigate the role of exosomes from adipose tissue-derived stromal cells (ADSCs) in OA. We explored whether exosomes from ADSCs could be absorbed by OA chondrocytes, whether there were differences in miR-429 expression in the exosomes of ADSCs and chondrocytes, and whether ADSC exosomal miR-429 could enhance chondrocyte proliferation to exert therapeutic effects in OA. STUDY DESIGN: Controlled laboratory study. METHODS: ADSCs were isolated and cultured from 4-week-old Sprague-Dawley rats. ADSCs and chondrocytes were identified by flow cytometry assay and fluorescent staining, respectively. The exosomes were extracted and identified. Exosome transport was verified by cell staining and co-culture. Beclin 1, collagen II, LC3-II/I, miR-429, and FEZ2 mRNA and protein expression were investigated with real-time PCR and western blotting, respectively. Chondrocyte proliferation was investigated with Cell Counting Kit-8 (CCK-8) assay. The association between miR-429 and FEZ2 was verified with luciferase assay. A rat OA model was established and rat knee joint cartilage tissue was examined with hematoxylin-eosin and toluidine blue staining. RESULTS: Both ADSCs and chondrocytes secreted exosomes and ADSC-derived exosomes could be absorbed by the chondrocytes. ADCS exosomes contained higher miR-429 levels than chondrocyte exosomes. The luciferase assay demonstrated that miR-429 directly targeted FEZ2. Compared with the OA group, miR-429 promoted chondrocyte proliferation while FEZ2 decreased it. miR-429 promoted autophagy by targeting FEZ2 to ameliorate cartilage injury. In vivo, miR-429 promoted autophagy to alleviate OA by targeting FEZ2. CONCLUSION: ADSC exosomes could be beneficial for OA and could be absorbed by chondrocytes to promote chondrocyte proliferation through miR-429. miR-429 ameliorated cartilage injury in OA by targeting FEZ2 and promoting autophagy.

Administration of Tranexamic Acid to Reduce Intra-articular Hemarthrosis in ACL Reconstruction: A Systematic Review.

BACKGROUND: Although tranexamic acid (TXA) has been shown to reduce bleeding in joint replacement procedures, its effectiveness for anterior cruciate ligament reconstruction (ACLR) has not been widely reported. PURPOSE: To evaluate the effectiveness of TXA to reduce postoperative hemarthrosis and improve clinical outcomes after ACLR. STUDY DESIGN: Systematic review; Level of evidence, 2. METHODS: A systematic review of the literature following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) was performed; literature retrieval was carried out using the MEDLINE, Embase, and Cochrane Library electronic databases. The inclusion criteria were comparative studies in English that reported the administration of intravenous or intra-articular TXA versus other modalities or placebo in patients undergoing ACLR. RESULTS: Six studies comprising 418 patients who were treated with TXA were included. Heterogeneity among studies did not allow for the pooling of data. Five studies showed decreased drainage volume in the first 24 or 48 hours postoperatively as compared with control (ACLR with no TXA). Four studies showed lower hemarthrosis grades and visual analog scale scores in TXA versus control in the early postoperative period, although this difference was not evident at 4 weeks postoperatively. No studies showed differences in infection, deep venous thrombosis, or adverse events between the TXA and control groups. CONCLUSION: The current best available evidence suggests that TXA administration at the time of ACLR results in decreased intra-articular bleeding (measured using a drainage system), hemarthrosis grade, and pain when compared with control.

Repair of rotator cuff tears in patients aged 75 years and older: Does it make sense? A systematic review.

Background: Rotator cuff injuries are common, and morbidity increases with age. The asymptomatic full-thickness tear rate is 40% in the over 75-year-old population. Purpose: This study aimed to systematically review the literature on the outcomes of rotator cuff repair among >75 years old patients. Study design: Systematic review. Methods: A systematic review of the literature was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A literature search was performed in the electronic databases of PubMed, Medline, Embase, and The Cochrane Library. Studies in English evaluating repair of full-thickness rotator cuff tears in patients aged >75 years were included. Results: Six studies were reviewed, including 311 patients (313 shoulders) treated with arthroscopic and/or open rotator cuff repair. Sixty-one patients were lost to follow-up, leaving 252 shoulders with outcome data. Patients in this age group demonstrated a significant improvement in the clinical and functional scores after rotator cuff repair, with a high satisfaction rate. The mean American Shoulder and Elbow Surgeons scores improved from 43.8 (range, 42.0-45.5) preoperatively to 85.3 (range, 84.0 to 86.5) postoperatively, and the mean Constant scores improved from 45.4 (range, 34.7-55.5) to 78.6 (range, 67.0-91.6). Pain, evaluated in all studies by the visual analog scale for pain, showed a significant improvement at the last follow-up compared with the mean preoperative score. Furthermore, range of motion and return to daily activities and sports gained marked improvements. Conclusion: Rotator cuff repair in patients aged >75 years could achieve high clinical success rates with good outcomes and pain relief. Although patients in this age group are at a high risk of retear, rotator cuff repair may offer a good option with significant functional and clinical improvement.

Is Isolated Hip Strengthening or Traditional Knee-Based Strengthening More Effective in Patients With Patellofemoral Pain Syndrome? A Systematic Review With Meta-analysis.

BACKGROUND: Focus on the importance of hip muscle strength in patients with patellofemoral pain syndrome (PFPS) has recently increased. It is unknown whether patients with PFPS will benefit more from hip strengthening compared with traditional knee-based strengthening. PURPOSE: To compare the efficiency of isolated hip strengthening versus traditional knee-based strengthening for patients with PFPS. STUDY DESIGN: Systematic review; Level of evidence, 2. METHODS: We conducted a search for studies comparing isolated hip strengthening and knee-based strengthening by using the MEDLINE, Embase, and Cochrane Library electronic databases. The methodological quality of included studies was assessed using the PEDro scale. Predetermined variables from each study were extracted and analyzed. RESULTS: A total of 5 comparative studies were included in this review; all studies were of moderate to high quality and reflected good internal and external validity. Pain (visual analog scale [VAS]) and function (Anterior Knee Pain Scale) scores improved in both the hip and knee groups after strengthening intervention, although no statistically significant differences were seen between groups in the pooled analysis. In 2 studies, VAS pain scores were reduced earlier for patients in the hip group than for those in the knee group (P < .05). In 1 study, improvement in Western Ontario and McMaster Universities Osteoarthritis Index function scores in the hip group was statistically superior compared with those in the knee group after intervention and at 6-month follow-up (P < .05). In 2 studies, patients in the hip group exhibited statistically greater hip abductor and extensor strength than did those in the knee group after intervention (P < .05). CONCLUSION: The best-available evidence suggests that overall, isolated hip strengthening and knee strengthening were equivalent for treatment of PFPS.

Association of MIR17HG and MIR155HG gene variants with steroid-induced osteonecrosis of the femoral head in the population of northern China.

INTRODUCTION: Steroid-induced osteonecrosis of the femoral head (ONFH) is a disease of the bone. Metabolism and genetic factors are generally considered to play an important role. The purpose of this study was to investigate the relationship between single-nucleotide polymorphisms (SNPs) in MIR17HG and MIR155HG and the risk of steroid-induced ONFH in the population of northern China. METHODS: A total of 199 steroid-induced ONFH patients and 506 healthy controls were recruited for the study. Four SNPs of MIR17HG and seven SNPs of MIR155HG were genotyped by Sequenom MassARRAY. ORs and 95% CIs were used to evaluate the relationship between these SNPs and steroid-induced ONFH. RESULTS: In the codominant model, patients with the MIR17HG SNPs (rs7318578) AA genotype had an increased risk of steroid-induced ONFH (OR = 1.79, p = 0.039); in the recessive model, patients with the MIR17HG SNP (rs7318578) AA genotype had an increased risk of steroid-induced ONFH (OR = 1.78, p = 0.032). Stratified analysis showed that a MIR17HG SNP (rs7318578) and the MIR155HG SNPs (rs77218221, rs11911469, rs34904192 and rs4143370) were closely related to different unornamented phenotypes of steroid-induced ONFH. Analysis of the clinical indicators revealed significant differences in high-density lipoprotein (HDL-C) levels between the ONFH group and the control group (p = 0.005). In the MIR17HG SNP (rs75267932), patients with different genotypes had different levels of triglyceride (TG). The MIR155HG SNPs (rs77699734, rs1893650, and rs34904192) showed differences in triglyceride (TG), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) levels in patients with different genotypes. CONCLUSION: Our results confirm that MIR17HG and MIR155HG gene mutations are associated with steroid-induced ONFH susceptibility in the population of northern China, providing new evidence for the early detection and prevention of ONFH.

Polycyclic aromatic hydrocarbons in surface waters from the seven main river basins of China: Spatial distribution, source apportionment, and potential risk assessment.

In this study, we report long-term measurements of Polycyclic Aromatic Hydrocarbons (PAHs) collected from the surface waters of seven river basins across China. The spatial distribution, source apportionment, and potential risk assessment of 16 USEPA designated PAHs were reviewed. Water samples were collected from the Songhua River Basin (SRB), Yangtze River Basin (YtRB), Yellow River Basin (YRB), Pearl River Basin (PRB), Huai River Basin (HuRB), Liao River Basin (LRB), and Hai River Basin (HRB). Our results show that the total PAH concentration in the surface waters from primary river basins ranged from 99.60 to 3805.00 ng/L in the dry season with a geometric mean value of 797.96 ng/L, and from 235.84 to 11,812.20 ng/L in the wet season with a geometric mean value of 820.75 ng/L. In the river basins examined, the geometric concentration of Σ16PAHs ranged from 215.50 ng/L to 1969.91 ng/L, with a median value of 837.73 ng/L. In the decreasing order across seven river basins, the geometric mean Σ16PAHs content varied as: SRB (1969.91 ng/L) > LRB (1155.87 ng/L) > YRB (884.06 ng/L) > PRB (837.73 ng/L) > HuRB (559.10 ng/L) > HRB (261.84 ng/L) > YtRB (215.50 ng/L). Moreover, the total PAH concentration was slightly lower in the dry season than in the wet season. The pollution level of PAHs in North China was higher than in South China. No discernible temporal trend was observed in Σ16PAHs observed in China during the past decade. Overall, PAHs designated for priority control measures were Nap, Phe, and Flu; as 2- and 3-ring PAHs were the dominant compounds in the river basins, accounting for 33.7% and 36.9% of the total PAHs, respectively. Source analysis revealed that coal and biomass combustion were the main contributors to PAHs in the river basins, accounting for about 40% of the total. The geometric mean concentrations of individual PAH, including BaP, BaA, BbF, BkF, Ind, and DaA in some water samples exceeded the environmental quality standards of both China and the United States. According to metrics describing eco-toxicity from water contamination, the river basin was at moderate risk in YtRB, YRB, PRB, HuRB, and HRB, but at high risk in SRB and LRB, suggesting that targeted control measures or remedial actions should be undertaken to decrease PAH contamination in China.

Evaluation of risk correlation between recurrence of patellar dislocation and damage to the medial patellofemoral ligament in different sites caused by primary patellar dislocation by MRI: a meta-analysis.

PURPOSE: Non-surgical treatment of primary patellar dislocation has a high risk of recurrent dislocation; thus, we tried to identify injuries in which sites of the medial patellofemoral ligament (MPFL) were most associated with recurrent dislocation by analyzing relevant original literature in order to provide improved suggestions on early surgical treatment. METHODS: According to the preset retrieval strategy, the original studies were retrieved until January 2020 using MEDLINE, Embase and Cochrane Library. Review Manager 5.3 software was used to summarize and compare the differences of recurrent dislocation of MPFL injuries at different attachments. RESULTS: Although the incidence of recurrent patellar dislocation at the femoral attachment of MPFL was higher overall (femoral only vs. patellar only vs. combined: 37.6% vs. 32.3% vs. 35.8%), no statistical difference was found among the three groups (femoral only vs. patellar only, RR = 1.32 [95% CI 0.89-1.95]; P = 0.17) (femoral only vs. combined, RR = 1.15 [95% CI 0.59-2.22]; P = 0.68) (patellar only vs. combined, RR = 0.94 [95% CI 0.69-1.29]; P = 0.72). In addition, the sulcus angle of recurrent dislocation group is significantly greater than that in the non-recurrent dislocation group (MD = 3.06 [95% CI 0.42-5.70]; P = 0.02). CONCLUSIONS: Based on the pooled data collected from the original studies available, the risk of recurrent patellar dislocation due to damage to the MPFL at different sites did not differ. Additionally, the sulcus angle in the group with recurrent dislocation was considerably higher when comparing with the group without recurrent dislocation, that is, the shallower and flatter of the trochlear groove, the higher the risk of recurrent patellar dislocation.

A meta-analysis comparing tenotomy or tenodesis for lesions of the long head of the biceps tendon with concomitant reparable rotator cuff tears.

BACKGROUND: The best treatment for lesions of the long head of the biceps tendon (LHBT) with concomitant reparable rotator cuff tears is still controversial. The purpose of the meta-analysis was to compare clinical outcomes of biceps tenotomy and tenodesis for LHBT lesions. METHODS: A literature retrieval was conducted in MEDLINE, Embase, and Cochrane Library from 1979 to March 2018. Comparative studies (level of evidence I or II) comparing tenotomy and tenodesis for LHBT lesions with concomitant reparable rotator cuff tears were included. Risk of bias for all included studies was assessed using the Cochrane Collaboration's risk of bias tool. Clinical outcomes compared were Popeye sign, Constant score, VAS pain score, cramping pain, elbow flexion and forearm supination strength, and re-tear of the rotator cuff. RESULTS: Two randomized controlled trials (RCTs) and five prospective cohort studies (PCS) with 288 biceps tenotomy patients and 303 biceps tenodesis patients were included in this review. Tenotomy resulted in significantly greater rates of Popeye sign (RR, 2.70 [95% CI, 1.80 to 4.04]; P < 0.01) and a less favorable Constant score (MD, - 1.09 [95% CI, - 1.90 to - 0.28]; P < 0.01) compared to tenodesis. No significant heterogeneity was found between the two groups across all parameters except forearm supination strength. CONCLUSIONS: The current evidence indicates that biceps tenodesis for LHBT lesions with concomitant reparable rotator cuff tears results in decreased rate of Popeye sign and improved Constant score compared to biceps tenotomy. TRIAL REGISTRATION: PROSPERO, CRD42018105504. Registered on 13 August 2018.

Is platelet-rich plasma an ideal biomaterial for arthroscopic rotator cuff repair? A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Recently, many authors have reported the effects of platelet-rich plasma (PRP) on rotator cuff repair. Whether PRP treatment during arthroscopic rotator cuff repair improves tendon healing rates or restores full function remains unknown. The purpose of this meta-analysis was to evaluate the clinical improvement and radiological outcomes of PRP treatment in patients undergoing arthroscopic rotator cuff repair. METHODS: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched. The study included only level 1 or 2 randomized controlled trials (RCTs) that compared the injection of platelet-rich plasma or platelet-rich fibrin matrix. The methodological quality of the trials was assessed using the Cochrane Handbook for Systematic Reviews of Interventions, 5.3. Continuous variables were analysed using the weighted mean difference, and categorical variables were assessed using relative risks. P < 0.05 was considered statistically significant. RESULTS: The meta-analysis revealed a lower retear rate following PRP treatment than that following the control method (mean difference, 1.10; 95% CI, 1.03 to 1.18; P = 0.004). Constant shoulder scores improved with PRP (mean difference, 2.31; 95% CI, 1.02 to 3.61; P = 0.0005). PRP treatment also resulted in higher UCLA scores (mean difference, 0.98; 95% CI, 0.27 to 1.69; P = 0.007), and simple shoulder test scores were improved (mean difference, 0.43; 95% CI, 0.11 to 0.75; P = 0.008). Finally, lower visual analogue scale scores were observed with PRP augmentation (mean difference, - 0.35; 95% CI, - 0.57 to - 0.13; P = 0.002). CONCLUSIONS: The current systematic review and meta-analysis reveals that PRP treatment with arthroscopic repair of rotator cuff tears decreases the retear rate and improves the clinical outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42016048416.