Does Pure Platelet-Rich Plasma Affect Postoperative Clinical Outcomes After Arthroscopic Rotator Cuff Repair? A Randomized Controlled Trial

Clinical efficacy and safety of platelet-rich plasma in arthroscopic full-thickness rotator cuff repair: A meta-analysis

BACKGROUND

Arthroscopic repair of rotator cuff tears, although commonly performed, carries the risk of retears. Therefore, bioremediation techniques such as platelet-rich plasma injections have been used as adjuvant therapies. The clinical efficacy of platelet-rich plasma in the arthroscopic repair of full-thickness rotator cuff injury is controversial. We performed a meta-analysis to evaluate the clinical effectiveness and safety of platelet-rich plasma and provide evidence-based medical recommendations for selecting the proper clinical treatment plan for full-thickness rotator cuff injuries.

METHODS

A search for the terms "platelet-rich plasma" and "rotator cuff" was performed in the PubMed, EMBASE, and Cochrane Library databases using a computer. After conducting quality evaluations and data extraction, RevMan 5.3 software was used to combine the effect sizes, and the GRADEpro Guideline Development Tool was used to rate the level of evidence from aspects of functional score, pain score and retear rate.

RESULTS

Eight randomized controlled trials involving 566 patients were included. The long-term retear rate(RR = 0.96, 95% CI [0.52, 1.78], P = .89), Constant score(RR = 0.96, 95% CI [0.52, 1.78], P = .89), and Visual Analog Scale score for pain (SMD = -0.28, 95% CI [-0.60, 0.04], P = .08), as well as both the long-term and short-term Disabilities of the Arm, Shoulder, and Hand scores(SMD = -0.13, 95% CI [-0.44, 0.18], P = .41;SMD = -0.02, 95% CI [-0.40, 0.36], P = .93), were not significantly different between the platelet-rich plasma and control groups. However, the short-term retear rate(RR = 0.29, 95% CI [0.13, 0.65], P = .003) and Visual Analog Scale score (SMD = -0.41, 95% CI [-0.62, -0.19], P = .0002) were significantly lower, while the short-term Constant score(SMD = 0.37, 95% CI [0.19, 0.55], P < .0001) and short-term and long-term University of California at Los Angeles activity scores (SMD = 0.38, 95% CI [0.16, 0.60], P = .0008;SMD = 0.85, 95% CI [0.48, 1.22], P < .00001) were significantly higher, in the platelet-rich plasma group than in the control group.

CONCLUSION

Platelet-rich plasma injection can effectively improve the short-term outcomes following arthroscopic repair of full-thickness rotator cuff tears, thus reducing the rate of retears, alleviating pain, and improving patients' shoulder function. Specifically, the clinical outcomes are better with the use of platelet-rich plasma in single-row fixation than in other fixation techniques. Therefore, platelet-rich plasma injection can be recommended as an adjuvant therapy in single-row repair for improved short-term results.

Rationale for Biologic Augmentation of Rotator Cuff Repairs

The structural integrity of rotator cuff repair (RCR) has been a primary focus for shoulder surgeons seeking long-term clinical and functional success. Improvements in surgical techniques have allowed for superior initial biomechanical fixation. However, tendon healing remains a significant clinical problem even after rigid time-zero repair. The lack of long-term healing has led to increased interest in biologic augmentation to improve tendon-to-bone healing. This interest has led to a rise in the investigation of small molecular therapies, cell-based strategies, and tissue-derived treatments offering surgeons a new therapeutic toolbox for potentially improving RCR long-term outcomes. However, the delivery, efficacy, and safety of these treatments remain under investigation. Additional well-designed, high-level studies are of paramount importance in creating evidence-based guidelines for the implementation of new biologic solutions. This review article discusses the current preclinical, translational, and clinical experience with and rationale for biologic augmentation in RCR.

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.

Epidemiological Analysis of Changes in Clinical Practice for Full-Thickness Rotator Cuff Tears From 2010 to 2015

Background:

Rotator cuff injuries are a leading cause of shoulder disability among adults. Surgical intervention is a common treatment modality; however, conservative management has been described for the treatment of rotator cuff tears. As the cost of health care increases, the industry has shifted to optimizing patient outcomes, reducing readmissions, and reducing expenditure. In 2010, the American Academy of Orthopaedic Surgeons created clinical practice guidelines (CPGs) to guide the management of rotator cuff injuries. Since their publication, there have been several randomized controlled trials assessing the management of rotator cuff injuries.

Purpose:

To quantitatively describe changes in the management of full-thickness rotator cuff tears over time with regard to the publication of the CPGs and prospective clinical trials.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Included in the study were Humana-insured patients in the PearlDiver database with the diagnosis of a full-thickness rotator cuff tear from 2010 to 2015. Patients undergoing rotator cuff repair (CPT-29827, CPT-23410, CPT-23412, CPT-23420) and patients undergoing nonoperative management in the queried years were identified. The incidence of physical therapy (PT), nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroid injections was assessed.

Results:

In 2015, patients with full-thickness rotator cuff tears were less likely to receive a corticosteroid injection (16.5% vs 23.9%, respectively; odds ratio [OR], 0.6; P < .001) or undergo PT (7.8% vs 12.1%, respectively; OR, 0.6; P < .001) before rotator cuff repair in comparison with 2010. Additionally, patients were no more likely to be prescribed NSAIDs before rotator cuff repair in 2015 in comparison with 2010 (OR, 1.0; P = .6). Patients with full-thickness rotator cuff tears were less likely to undergo acromioplasty in 2015 in comparison with 2010 (48.2% vs 76.9%, respectively; OR, 0.4; P < .001); however, the rate of concomitant biceps tenodesis slightly increased (14.8% vs 14.6%, respectively; OR, 1.1; P = .01).

Conclusion:

From 2010 to 2015, there were changes in the management of full-thickness rotator cuff tears, including decreased preoperative utilization of corticosteroid injections and PT as well as a decrease in concomitant acromioplasty, and the rate of biceps tenodesis slightly increased. As CPGs and prospective investigations continue to proliferate, management practices of patients with full-thickness rotator cuff tears continue to evolve.

Autologous Conditioned Plasma for tendon healing following arthroscopic rotator cuff repair. Prospective comparative assessment with magnetic resonance arthrography at 6 months' follow-up

INTRODUCTION

Despite improvements in technique and materials for rotator cuff repair, mean re-tear rates remain close to 30%. The aim of the present study was to assess injection of Autologous Conditioned Plasma (ACP™, Arthrex) for tendon healing after arthroscopic repair. The study hypothesis was that ACP™ improves the tendon-healing rate.

MATERIAL AND METHOD

A non-randomized comparative prospective study included all patients aged over 18 years operated on in 2010 for arthroscopic repair of full-thickness rotator cuff tear with≤2 fatty degeneration on the Goutallier classification, whatever the severity of retraction, on virgin non-osteoarthritic shoulder without contraindications for magnetic resonance (MR) arthrography. The surgical protocol was standardized. The first half of the patient sample received end-of-procedure ACP™ injection to the repaired tendon, tuberosity freshening surface and subacromial space, and the second (control) half received no supplementary treatment. The main endpoint was tendon healing on MR arthrography at 6 months according to Sugaya. Secondary endpoints comprised shoulder pain at rest on a numerical scale (0=no pain to 10=worst imaginable pain) and Constant functional score.

RESULTS

Two of the 58 patients refused MR arthrography and 7 were lost to follow-up. Forty-nine patients (26 ACP™, 23 controls) were analyzed: 20 male, 29 female; mean age, 61±7.3 years. There were no significant intergroup differences in healing rate at 6 months (ACP™ 73.1% vs. 78.3% controls; p=0.75), shoulder pain (2±1.8 vs. 2.6±1.7, respectively; p=0.24), or Constant score (77±13.5/100 vs. 72.4±12.3, respectively; p=0.18).

CONCLUSION

Associating ACP™ did not improve healing after arthroscopic rotator cuff repair. Sample size, however, had been calculated for a large expected difference, leading to lack of power.

LEVEL OF EVIDENCE

III; case-control study.

Bone marrow stimulation decreases retear rates after primary arthroscopic rotator cuff repair: a systematic review and meta-analysis

BACKGROUND

Despite the optimization of biomechanical and patient factors in the setting of rotator cuff repair (RCR), postoperative retear rates remain high in many series reported in the literature. Preclinical studies have suggested bone marrow stimulation (BMS) at the rotator cuff footprint may reduce the rate of retear after RCR. The objective of this meta-analysis was to analyze the clinical evidence investigating the effect of arthroscopic RCR, with and without BMS, on rotator cuff healing and functional outcomes.

METHODS

PubMed, MEDLINE, Embase, and the Cochrane Library were searched through December 2017. Two reviewers selected studies based on the inclusion criteria and assessed methodologic quality. Pooled analyses were performed for continuous and binomial variables where appropriate.

RESULTS

Four studies (365 patients), including 2 Level I randomized controlled trials and 2 Level III retrospective comparative cohort studies were included. There was no statistical difference in the Disabilities of the Arm, Shoulder and Hand score, University of California Los Angeles Shoulder Rating Scale score, or the Constant score between the BMS and conventional repair groups. The pooled retear rates were 18.4% (28 of 152) and 31.8% (56 of 176) for patients treated with and without BMS, respectively. The pooled analysis of rotator cuff retear rates from the 4 studies (328 patients) showed a statistically significant difference favoring BMS over conventional repair (odds ratio, 0.42; 95% confidence interval, 0.25-0.73; P = .002; I² = 0%).

CONCLUSION

BMS reduces the retear rate after RCR but shows no difference in functional outcomes compared with conventional repair. This study provides evidence for the use of BMS as a potential cost-effective biological approach toward improving rotator cuff healing.

The Efficacy of Platelet-Rich Plasma and Platelet-Rich Fibrin in Arthroscopic Rotator Cuff Repair: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Basic science studies suggest that platelet-rich therapies have a positive effect on tendon repair. However, the clinical evidence is conflicted on whether this translates to increased tendon healing and improved functional outcomes.

PURPOSE

To perform a systematic review of randomized controlled trials (RCTs) in the literature to ascertain whether platelet-rich plasma (PRP) or platelet-rich fibrin (PRF) improved patient outcomes in arthroscopic rotator cuff repair.

STUDY DESIGN

Meta-analysis.

METHODS

Two independent reviewers performed the literature search based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, with a third author resolving any discrepancies. RCTs comparing PRP or PRF to a control in rotator cuff repair were included. Quality of evidence was assessed using the Jadad score. Clinical outcomes were compared using the risk ratio for dichotomous variables and the mean difference for continuous variables. A P value <.05 was deemed statistically significant.

RESULTS

Eighteen RCTs with 1147 patients were included in this review. PRP resulted in significantly decreased rates of incomplete tendon healing for all tears combined (17.2% vs 30.5%, respectively; P < .05), incomplete tendon healing in small-medium tears (22.4% vs 38.3%, respectively; P < .05), and incomplete tendon healing in medium-large tears (12.3% vs 30.5%, respectively; P < .05) compared to the control. There was a significant result in favor of PRP for the Constant score (85.6 vs 83.1, respectively; P < .05) and the visual analog scale score for pain at 30 days postoperatively (2.9 vs 4.3, respectively; P < .05) and at final follow-up (1.2 vs 1.4, respectively; P < .05) compared to the control. PRF did not result in a significantly decreased rate of incomplete tendon healing for all tears combined (23.0% vs 24.6%, respectively; P = .74) or an improved Constant score (80.8 vs 79.8, respectively; P = .27) compared to the control. PRF resulted in a significantly longer operation time (99.1 vs 83.3 minutes, respectively; P< .05) compared to the control.

CONCLUSION

The current evidence indicates that the use of PRP in rotator cuff repair results in improved healing rates, pain levels, and functional outcomes. In contrast, PRF has been shown to have no benefit in improving tendon healing rates or functional outcomes.

Platelet-Rich Plasma

Platelet-rich plasma (PRP) is a promising treatment for musculoskeletal maladies and clinical data to date have shown that PRP is safe. However, evidence of its efficacy has been mixed and highly variable depending on the specific indication. Additional future high-quality large clinical trials will be critical in shaping our perspective of this treatment option. The heterogeneity of PRP preparations, both presently and historically, leads sweeping recommendations about its utility impossible to make. This heterogeneity has also made interpreting existing literature more complicated.

Current Clinical Recommendations for Use of Platelet-Rich Plasma

PURPOSE OF REVIEW

This review evaluates current clinical literature on the use of platelet-rich plasma (PRP), including leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP), in order to develop evidence-based recommendations for various musculoskeletal indications.

RECENT FINDINGS

Abundant high-quality evidence supports the use of LR-PRP injection for lateral epicondylitis and LP-PRP for osteoarthritis of the knee. Moderate high-quality evidence supports the use of LR-PRP injection for patellar tendinopathy and of PRP injection for plantar fasciitis and donor site pain in patellar tendon graft BTB ACL reconstruction. There is insufficient evidence to routinely recommend PRP for rotator cuff tendinopathy, osteoarthritis of the hip, or high ankle sprains. Current evidence demonstrates a lack of efficacy of PRP for Achilles tendinopathy, muscle injuries, acute fracture or nonunion, surgical augmentation in rotator cuff repair, Achilles tendon repair, and ACL reconstruction. PRP is a promising treatment for some musculoskeletal diseases; however, evidence of its efficacy has been highly variable depending on the specific indication. Additional high-quality clinical trials with longer follow-up will be critical in shaping our perspective of this treatment option.

The effect of autologous platelet rich plasma on tenocytes of the human rotator cuff

Background

Platelet rich plasma (PRP) is widely used in rotator cuff repairs but its effect on the healing process is unclear. Several cell culture studies on the effect of allogenic PRP have reported promising results but are not transferable to clinical practice.

The aim of the present study is to assess the possible effect of autologous PRP on rotator cuff tendon cells. The amount of growth factors involved with tendon-bone healing (PDGF-AB, IGF-1, TGF-β1, BMP-7 and -12) is quantified.

Methods

Rotator cuff tissue samples were obtained from (n = 24) patients grouped by age (>/< 65 years) and sex into four groups and cells were isolated and characterized. Later, autologous PRP preparations were obtained and the effect was analyzed by means of cell proliferation, collagen I synthesis and expression of collagen I and III. Furthermore, the PRPs were quantified for growth factor content by means of platelet-derived growth factor (PDGF-AB), insulin-like growth factor (IGF-1), transforming growth factor (TGF-β1), as well as bone morphogenetic protein (BMP) -7 and − 12.

Results

Cell proliferation and absolute synthesis of collagen I were positively affected by PRP exposure compared to controls (p < 0.05), but expression and relative synthesis of collagen I (normalized to cell proliferation) were significantly reduced.

PRP contained high amounts of IGF-1 and lower levels of TGF-β1 and PDGF-AB. The amounts of BMP-7 and -12 were below the detection limits.

Conclusions

PRP is a source of growth factors such involved with tendon-bone healing. PRP had an anabolic effect on the human rotator cuff tenocytes of the same individual in vitro by means of cell proliferation and absolute, but not relative collagen I synthesis.

These results encourage further studies on clinical outcomes with more comparable standards in terms of preparation and application methods.

Level of evidence

Controlled laboratory study.

Myths and Facts of In-Office Regenerative Procedures for Tendinopathy

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

Differing efficacies of autologous platelet-rich plasma treatment in reducing pain following rotator-cuff injury in a single patient

Rotator-cuff tears (RCTs) are typically associated with chronic pain. The most common treatment for reducing pain is the injection of cortisone into the injury site. An alternative and increasingly used technique is the injection of autologous platelet-rich plasma (PRP). A limitation of cortisone is its pain relief is short-lived, while PRP has the limitation of providing pain relief to only about 50% of patients, making its efficacy questioned, although when it is effective, its efficacy is longer than cortisone. Little is known about what accounts for these limitations. This paper presents results from a patient with RCTs causing excruciating pain who received an injection of PRP into that shoulder resulting in complete pain elimination that was ongoing at 2 years and 2 months. When 7-month severe posttrauma pain associated with the RCT developed in the contralateral shoulder, PRP prepared the same way and injected by the same person who performed the first injection provided no pain relief. However, a subsequent single cortisone injection resulted in complete pain elimination, which was ongoing at >15 months. These observations indicate that PRP can have inconsistent effects in reducing pain, not only between patients but also within the same patient. Further, although the pain relief induced by cortisone is normally not long-lasting, when given following a PRP injection, it can induce complete pain relief lasting >15 months. This paper discusses possible reasons for the variability in PRP efficacy on pain relief and addresses the possibility that when administered together, PRP and cortisone may act in a complementary manner, leading to significantly greater and longer-lasting pain relief.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

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

Bone marrow mesenchymal stem cells do not enhance intra-synovial tendon healing despite engraftment and homing to niches within the synovium

Background

Intra-synovial tendon injuries display poor healing, which often results in reduced functionality and pain. A lack of effective therapeutic options has led to experimental approaches to augment natural tendon repair with autologous mesenchymal stem cells (MSCs) although the effects of the intra-synovial environment on the distribution, engraftment and functionality of implanted MSCs is not known. This study utilised a novel sheep model which, although in an anatomically different location, more accurately mimics the mechanical and synovial environment of the human rotator cuff, to determine the effects of intra-synovial implantation of MSCs.

Methods

A lesion was made in the lateral border of the lateral branch of the ovine deep digital flexor tendon within the digital sheath and 2 weeks later 5 million autologous bone marrow MSCs were injected under ultrasound guidance into the digital sheath. Tendons were recovered post mortem at 1 day, and 1–2, 4, 12 and 24 weeks after MSC injection. For the 1-day and 1–2-week groups, MSCs labelled with fluorescent-conjugated magnetic iron-oxide nanoparticles (MIONs) were tracked with MRI, histology and flow cytometry. The 4, 12 and 24-week groups were implanted with non-labelled cells and compared with saline-injected controls for healing.

Results

The MSCs displayed no reduced viability in vitro to an uptake of 20.0 ± 4.6 pg MIONs per cell, which was detectable by MRI at minimal density of ~ 3 × 10⁴ cells. Treated limbs indicated cellular distribution throughout the tendon synovial sheath but restricted to the synovial tissues, with no MSCs detected in the tendon or surgical lesion.

The lesion was associated with negligible morbidity with minimal inflammation post surgery. Evaluation of both treated and control lesions showed no evidence of healing of the lesion at 4, 12 and 24 weeks on gross and histological examination.

Conclusions

Unlike other laboratory animal models of tendon injury, this novel model mimics the failed tendon healing seen clinically intra-synovially. Importantly, however, implanted stem cells exhibited homing to synovium niches where they survived for at least 14 days. This phenomenon could be utilised in the development of novel physical or biological approaches to enhance localisation of cells in augmenting intra-synovial tendon repair.

Injection Therapies for Rotator Cuff Disease

Rotator cuff disease affects a large proportion of the overall population and encompasses a wide spectrum of pathologies, including subacromial impingement, rotator cuff tendinopathy or tear, and calcific tendinitis. Various injection therapies have been used for the treatment of rotator cuff disease, including corticosteroid, prolotherapy, platelet-rich plasma, stem cells, and ultrasound-guided barbotage for calcific tendinitis. However, the existing evidence for these therapies remains controversial or sparse. Ultimately, improved understanding of the underlying structural and compositional deficiencies of the injured rotator cuff tissue is needed to identify the biological needs that can potentially be targeted with injection therapies.

The Role of Biologic Therapy in Rotator Cuff Tears and Repairs

PURPOSE OF REVIEW

The purpose of this review was to establish the foundation of the major biologic adjuvants to rotator cuff repairs and review recent scientific findings.

RECENT FINDINGS

Platelet-rich plasma (PRP) overall has no significant impact on functional outcomes and repair integrity, but may be more advantageous in small to medium tears. Further studies should focus on leukocyte-rich versus poor preparations and the use of PRP in patients that are high risk for repair failure. Biologic and synthetic patches or augments provide mechanical stability for large and massive rotator cuff tears and decrease re-tear rates. Mesenchymal stem cells have demonstrated improved healing rates without an impact on outcomes. Cytokines and growth factors show promise in animal models, but require human trials to further evaluate. In massive or revision repairs, allograft or synthetic patch augmentation should be considered. Platelet-rich plasma may have benefit in smaller tears. Further studies are needed to evaluate the value of mesenchymal stem cells and various cytologic chemical signals.

Comparative Analysis of Different Platelet Lysates and Platelet Rich Preparations to Stimulate Tendon Cell Biology: An In Vitro Study

The poor healing potential of tendons is still a clinical problem, and the use of Platelet Rich Plasma (PRP) was hypothesized to stimulate healing. As the efficacy of PRPs remains unproven, platelet lysate (PL) could be an alternative with its main advantages of storage and characterization before use. Five different blood products were prepared from 16 male donors: human serum, two PRPs (Arthrex, (PRP-ACP); RegenLab (PRP-BCT)), platelet concentrate (apheresis, PC), and PL (freezing-thawing destruction of PC). Additionally, ten commercial allogenic PLs (AlloPL) from pooled donors were tested. The highest concentration of most growth factors was found in AlloPL, whereas the release of growth factors lasted longer in the other products. PRP-ACP, PRP-BCT, and PC significantly increased cell viability of human tenocyte-like cells, whereas PC and AlloPL increased Col1A1 expression and PRP-BCT increased Col3A1 expression. MMP-1, IL-1β, and HGF expression was significantly increased and Scleraxis expression decreased by most blood products. COX1 expression significantly decreased by PC and AlloPL. No clear positive effects on tendon cell biology could be shown, which might partially explain the weak outcome results in clinical practice. Pooled PL seemed to have the most beneficial effects and might be the future in using blood products for tendon tissue regeneration.

Editorial Commentary: Don't Pig Out When Selecting a Shoulder, Rotator Cuff Augmentation Graft! Xenografts Are Not the Way to Go

Porcine xenograft dermal onlay augmentation of rotator cuff repair does not provide improved cuff integrity or provide better clinical outcomes. The retear rate was actually higher in repairs augmented with a porcine xenograft than the control group. Adverse events occurred in 60% of the xenograft patients compared with 40% of the controls. The use of liquid platelet-rich plasma had no discernible impact. A total of 85% of the observed failures with the suture-bridging double-row repair were at the medial cuff (Cho type 2).

Porcine Dermis Patch Augmentation of Supraspinatus Tendon Repairs: A Pilot Study Assessing Tendon Integrity and Shoulder Function 2 Years After Arthroscopic Repair in Patients Aged 60 Years or Older

PURPOSE

To investigate the 2-year postoperative clinical and subjective outcomes after arthroscopic rotator cuff repair (ARCR) with xenologous porcine dermal patch augmentation compared with ARCR alone.

METHODS

Patients aged 60 years or older with a complete supraspinatus (SSP) tendon tear underwent primary ARCR with a transosseous-equivalent technique. By use of a matched-pair comparative trial design, a consecutive series of 20 patients receiving additional xenologous porcine dermal patch augmentation (patch group) was matched by tear location with 20 patients who received ARCR only (control group). Prior conservative treatment failed in all patients. Patients with concomitant pathologies precluding accurate repair assessment, partial or open reconstruction, or a latissimus dorsi and/or pectoralis major muscle transfer were excluded. Patients reported daily pain levels for 10 days after surgery. Clinical parameters and various patient-reported outcome scores were documented preoperatively and at 3, 6, and 24 months after surgery. Repair integrity was determined by magnetic resonance imaging or ultrasound at 24 months. Adverse events were recorded. Group outcome differences were analyzed with t tests, Fisher exact tests, and mixed models.

RESULTS

Patients in both groups were aged 67 years on average (range, 60-74 years), and 70% of patients were men. Patients in the patch group had slightly more SSP fatty infiltration preoperatively. Patch surgical procedures were on average 22 minutes longer than control interventions (P = .003). At 24 months, 4 patients and 9 patients were diagnosed with a recurrent SSP tendon defect in the control group (n = 20) and patch group (n = 19), respectively (relative risk, 2.4; P = .096). Of 11 defects (85%) identified as medial cuff failure, 8 occurred in the patch group. Pain rated by all patients decreased from postoperative day 1 to day 10 without any significant group difference (P = .348). No significant group differences were noted for other outcome parameters, and recurrent defects had no relevant effect on functional outcomes. Local complications (including recurrent defects) occurred in 8 patients in the control group and 12 in the patch group (P = .343).

CONCLUSIONS

Our pilot study supports the view that an SSP tear repair with porcine dermal xenograft augmentation does not benefit patients in terms of reducing the risk of a recurrent tendon defect or improving shoulder function up to 24 months after surgical repair.

LEVEL OF EVIDENCE

Level III, therapeutic study, retrospective comparative trial.

A Midterm Evaluation of Postoperative Platelet-Rich Plasma Injections on Arthroscopic Supraspinatus Repair: A Randomized Controlled Trial

BACKGROUND

Platelet-rich plasma (PRP) has been applied as an adjunct to rotator cuff repair to improve tendon-bone healing and potentially reduce the incidence of subsequent tendon retears.

PURPOSE

To investigate whether the midterm clinical and radiographic outcomes of arthroscopic supraspinatus repair are enhanced after repeated postoperative applications of PRP.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 60 patients (30 control; 30 PRP) were initially randomized to receive 2 ultrasound-guided injections of PRP to the tendon repair site at 7 and 14 days after double-row arthroscopic supraspinatus repair or not. A total of 55 patients (91.7%) underwent a clinical review and magnetic resonance imaging (MRI) at a mean of 3.5 years after surgery (range, 36-51 months). Patient-reported outcome measures (PROMs) included the Constant score, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire, Oxford Shoulder Score (OSS), and visual analog scale (VAS) for pain. Global rating of change (GRC) scale and patient satisfaction scores were evaluated. Structural integrity of the surgical repair was assessed via MRI using the Sugaya classification system.

RESULTS

At the midterm review, there was no difference between the groups for any of the PROMs. No differences between the groups were demonstrated for the subjective and range of motion subscales of the Constant score, although a significantly higher Constant strength subscale score was observed in the PRP group (3.3 points; 95% CI, 1.0-5.7; P = .006). There was no evidence for any group differences in MRI scores or retear rates, with 66.7% of PRP patients and 64.3% of control patients rated as Sugaya grade 1. Two control patients had symptomatic retears (both full thickness) within the first 16 weeks after surgery compared with 2 PRP patients, who suffered symptomatic retears (both partial thickness) between 16 weeks and a mean 3.5-year follow-up.

CONCLUSION

Significant postoperative clinical improvements and high levels of patient satisfaction were observed in patients at the midterm review after supraspinatus repair. While pain-free, maximal abduction strength was greater in the midterm after PRP treatment, repeated applications of PRP delivered at 7 and 14 days after surgery provided no additional benefit to tendon integrity.

Advances in biologic augmentation for rotator cuff repair

Rotator cuff tear is a very common shoulder injury that often necessitates surgical intervention for repair. Despite advances in surgical techniques for rotator cuff repair, there is a high incidence of failure after surgery because of poor healing capacity attributed to many factors. The complexity of tendon-to-bone integration inherently presents a challenge for repair because of a large biomechanical mismatch between the tendon and bone and insufficient regeneration of native tissue, leading to the formation of fibrovascular scar tissue. Therefore, various biological augmentation approaches have been investigated to improve rotator cuff repair healing. This review highlights recent advances in three fundamental approaches for biological augmentation for functional and integrative tendon-bone repair. First, the exploration, application, and delivery of growth factors to improve regeneration of native tissue are discussed. Second, applications of stem cell and other cell-based therapies to replenish damaged tissue for better healing are covered. Finally, this review will highlight the development and applications of compatible biomaterials to both better recapitulate the tendon-bone interface and improve delivery of biological factors for enhanced integrative repair.