Trends in utilization, demographics, and costs of platelet-rich plasma injections: a ten-year nationwide investigation

INTRODUCTION

Platelet-Rich Plasma (PRP) has become one of the most popular biologic treatments in orthopedic surgery. Despite this, its utilization over the last decade has not been investigated.

METHODS

We conducted a search using Current Procedural Terminology codes to identify patients who received PRP injections between 2010 and 2019 using the PearlDiver database. The purpose was to 1) determine annual trends of PRP injections of the ankle, hip, knee, shoulder, and elbow for cartilaginous, tendinous, ligamentous, meniscal/labral, and miscellaneous pathologies; 2) compare baseline demographics of patients receiving these injections; and 3) analyze costs.

RESULTS

A total of 23,716 patients who received PRP injections were identified; 54.4% were female. The incidence of PRP injections was between 1.6 and 4.3 per 100,000 orthopedic patients. The most common anatomic locations targeted for PRP therapy was the knee (36.7%), followed by the shoulder/elbow (30.5%), then the ankle (19.6%) and hip (13.6%). Subgroup analysis revealed that most common use of PRP was for knee cartilaginous pathologies, followed by shoulder/elbow tendinous pathologies. The number of injections used in the knee significantly increased between 2010 and 2019 (p< 0.001), and trended toward significantly increasing in the shoulder/elbow (p = 0.055). Average annual costs for PRP injections ranged from $711.65 for ankles and $1,711.63 for hips; costs significantly changed for 3 of the 4 anatomic locations. By 2019, average PRP injection costs for each area clustered around $1000.

CONCLUSION

Between 2010 and 2019, there was an increase in usage of PRP injections in the knee (cartilaginous pathologies) and the shoulder/elbow (tendinous pathologies). PRP costs demonstrated early variability but clustered around $1000 by 2019. Further studies into drivers of prices and cost-effectiveness of PRP are needed to provide clarity into the true costs to patients and healthcare providers.

Sourcing and development of tissue for transplantation in reconstructive surgery: A narrative review

The wealth of allogeneic and xenogeneic tissue products available to plastic and reconstructive surgeons has allowed for the development of novel surgical solutions to challenging clinical problems, often obviating the need to inflict donor site morbidity. Allogeneic tissue used for reconstructive surgery enters the tissue industry through whole body donation or reproductive tissue donation and has been regulated by the FDA as human cells, tissues, and cellular and tissue-based products (HCT/Ps) since 1997. Tissue banks offering allogeneic tissue can also undergo voluntary regulation by the American Association of Tissue Banks (AATB). Tissue prepared for transplantation is sterilized and can be processed into soft tissue or bone allografts for use in surgical reconstruction, whereas non-transplant tissue is prepared for clinical training and drug, medical device, and translational research. Xenogeneic tissue, which is most often derived from porcine or bovine sources, is also commercially available and is subject to strict regulations for animal breeding and screening for infectious diseases. Although xenogeneic products have historically been decellularized for use as non-immunogenic tissue products, recent advances in gene editing have opened the door to xenograft organ transplants into human patients. Herein, we describe an overview of the modern sourcing, regulation, processing, and applications of tissue products relevant to the field of plastic and reconstructive surgery.

Effect of CCR2 Knockout on Tendon Biomechanical Properties in a Mouse Model of Delayed Rotator Cuff Repair

BACKGROUND

The high incidence of incomplete or failed healing after rotator cuff repair (RCR) has led to an increased focus on the biologic factors that affect tendon-to-bone healing. Inflammation plays a critical role in the initial tendon-healing response. C-C chemokine receptor type 2 (CCR2) is a chemokine receptor linked to the recruitment of monocytes in early inflammatory stages and is associated with an increase in pro-inflammatory macrophages. The purpose of this study was to evaluate the role of CCR2 in tendon healing following RCR in C57BL/6J wildtype (WT) and CCR2-/- knockout (CCR2KO) mice in a delayed RCR model.

METHODS

Fifty-two 12-week-old, male mice were allocated to 2 groups (WT and CCR2KO). All mice underwent unilateral supraspinatus tendon (SST) detachment at the initial surgical procedure, followed by a delayed repair 2 weeks later. The primary outcome measure was biomechanical testing. Secondary measures included histology, gene expression analysis, flow cytometry, and gait analysis.

RESULTS

The mean load-to-failure was 1.64 ± 0.41 N in the WT group and 2.50 ± 0.42 N in the CCR2KO group (p = 0.030). The mean stiffness was 1.43 ± 0.66 N/mm in the WT group and 3.00 ± 0.95 N/mm in the CCR2KO group (p = 0.008). Transcriptional profiling demonstrated 7 differentially expressed genes (DEGs) when comparing the CCR2KO and WT groups (p < 0.05) and significant differences in Type-I and Type-II interferon pathway scores (p < 0.01). Flow cytometry demonstrated significant differences between groups for the percentage of macrophages present (8.1% for the WT group compared with 5.8% for the CCR2KO group; p = 0.035). Gait analysis demonstrated no significant differences between groups.

CONCLUSIONS

CCR2KO may potentially improve tendon biomechanical properties by decreasing macrophage infiltration and/or by suppressing inflammatory mediator pathways in the setting of delayed RCR.

CLINICAL RELEVANCE

CCR2 may be a promising target for novel therapeutics that aim to decrease failure rates following RCR.

Poster 130: Tendon-to-bone Healing in a CCR2 Knockout Mouse Model of Delayed Rotator Cuff Repair

Objectives:

Rotator cuff tears are one of the most prevalent musculoskeletal injuries with over 250,000 rotator cuff repairs performed annually in the Unites States. While surgical techniques have advanced, incomplete/failed healing after rotator cuff repair is still relatively common with rates ranging from 11-95%. Extrinsic factors such as excessive early activity and patient comorbidities such as smoking and diabetes have been previously identified as factors which may contribute to decreased rates of rotator cuff repair healing. However, there has been a recent focus on the intrinsic biologic factors which affect repair healing at the tendon-bone interface. CCR2 is a chemokine receptor that has been linked to the recruitment of monocytes into wound sites in early inflammatory stages and is associated with an increase in “pro-inflammatory” macrophages. The purpose of this study was to evaluate the role of CCR2 on rotator cuff tendon healing by evaluating relative gene expression and biomechanics following rotator cuff repair in wildtype (WT) and CCR2-/- knockout (KO) mice in a chronic rotator cuff injury model. We hypothesized that CCR2 KO would lead to decreased inflammatory cell recruitment and increased biomechanical properties after rotator cuff repair compared to WT mice.

Methods:

All procedures were approved by our Institutional Animal Care and Use Committee (Protocol# 2019-0021). A total of 28 12-week-old male mice were utilized for this study and divided into 2 groups (wildtype C57BL/6J and CCR2 KO). All mice underwent unilateral supraspinatus tendon detachment at the initial surgery, followed by delayed supraspinatus repair 2 weeks following the initial procedure. They were sacrificed at the 4-week time point following the second procedure (Fig 1). The primary outcome measures included biomechanical testing and gene expression analysis. Biomechanical testing was performed on the repaired rotator cuff tendons on a custom-designed materials testing system. Contralateral intact tendons were also tested as controls. Specimens were prepared and loaded to failure at a rate of 1mm/min. Load-to-failure data were recorded and stiffness was calculated from the load-deformation curves. Following total RNA isolation from both the control and repaired tendons (50ng) and muscles (100ng), gene expression was measured using the NanoString nCounter® Fibrosis Panel. Genes were assessed based on fold change and significance level, determined by adjusted p-values using the Benjamini-Yekutieli procedure. The significance level was set at p=0.05 for all statistical analyses.

Results:

All repaired tendons remained intact at the time of sacrifice 4 weeks following repair. The CCR2 KO group had thicker, more robust tendons on gross inspection than the WT controls. Biomechanical analysis demonstrated a significantly increased load-to-failure and stiffness of the supraspinatus tendon repair in the CCR2 KO group compared to the WT group. Mean load-to-failure in the WT group was 1.64 N ± 0.41 N versus 2.50 N ± 0.42 N in the CCR2 KO group (p<0.001) (Fig 2A). Mean stiffness in the WT group was 1.43 ± 0.66 N/mm versus 3.00 ± 0.95 N/mm in the CCR2 KO group (p=0.001) (Fig 2B). There were significant differences in both load-to-failure and stiffness between the repaired tendons and the intact contralateral tendons in both the WT and CCR2 KO groups (p<0.001). There were no significant differences in load-to-failure or stiffness between the WT and CCR2 KO controls. The site of failure was in the tendon midsubstance for all of the rotator cuff repair samples in both groups. NanoString analysis comparing WT repaired tendons with WT controls revealed 42 differentially expressed genes (see Fig 3 for relative pathway scores). There was significantly increased expression of Ccr2 in the WT repair group compared to the WT control group (log2 fold ratio: 3.28, 95% CI 2.63 to 3.94, p=0.003). NanoString analysis of the repaired tendon samples confirmed lower expression of Ccr2 in the repaired tendons of the CCR2 KO mice compared to WT tendons. There were no significant differences in expression ratios of the supraspinatus muscle samples between the CCR2 KO repair group and the WT repair group. There were also no significant differences in gene expression between the CCR2 KO repair group and the CCR2 KO control group muscles.

Conclusions:

In this study, we utilized a delayed rotator cuff repair model, which is more clinically relevant than previously established models of acute tendon transection and repair. Utilizing CCR2 KO mice, we found that there were significant differences in biomechanical properties – both load-to-failure and stiffness – between the WT mice and the CCR2 KO mice. Given the role of CCR2 in recruitment and accumulation of pro-inflammatory macrophages, these data suggest that excessive or unresolved inflammation may hinder tendon healing. Our results suggest that CCR2 KO leads to improved biomechanical properties in a mouse model of delayed rotator cuff repair. Additional studies are necessary to further elucidate the role of CCR2 in inflammation in the setting of chronic rotator cuff disease; however, CCR2 may be a promising target for novel therapeutics which aim to improve tendon healing and decrease re-tear rates following rotator cuff repair.

Off-the-Shelf Nipple Engineering: Neonipple Formation via Implantation of Scaffolded Decellularized Ovine Xenograft

BACKGROUND

Nipple reconstruction is widely regarded as the final step in postmastectomy breast reconstruction. While grafts, local flaps, or combination approaches have been used in nipple reconstruction, none has been able to achieve reliable long-term projection preservation. In response, we have sought to bioengineer neonipples in situ via the implantation of processed, decellularized cartilage xenografts placed within 3-dimensional-printed polylactic acid (PLA) scaffolds.

MATERIALS AND METHODS

External nipple scaffolds were designed in-house and 3-dimensional-printed with PLA filament. Decellularized ovine xenograft infill was prepared and processed by mincing or zesting. All nipple scaffolds were placed subcutaneously on the dorsa of Sprague-Dawley rats and explanted after 1, 3, and 6 months for analysis.

RESULTS

Explanted nipple scaffolds demonstrated gross maintenance of scaffold shape, diameter, and projection with accompanying increases in tissue volume. Histologic analyses revealed preservation of native cartilage architecture after 6 months without evidence of degradation. Analysis of formed tissue within the scaffolds revealed a progressive invasion of fibrovascular tissue with identifiable vascular channels and adipose tissue after 6 months in vivo. Confined compression testing revealed equilibrium moduli of both minced and zested samples that were within the expected range of previously reported human nipple tissue, while these data revealed no differences in the mechanical properties of the neotissue between time points or processing techniques.

CONCLUSIONS

These preliminary data support potential use of decellularized allograft to foster healthy tissue ingrowth within a PLA scaffold, thereby offering a novel solution to current limitations in nipple reconstruction.

World trauma education: hemorrhage control training for healthcare providers in India

Background

Hemorrhage remains a major cause of death around the world. Eighty percent of trauma patients in India do not receive medical care within the first hour. The etiology of these poor outcomes is multifactorial. We describe findings from the first Stop the Bleed (StB) course recently offered to a group of medical providers in southern India.

Methods

A cross-sectional survey of 101 participants who attended StB trainings in India was performed. Pre-training and post-training questionnaires were collected from each participant. In total, 88 healthcare providers’ responses were analyzed. Three bleeding control skills were presented: wound compression, wound packing, and tourniquet application.

Results

Among participants, only 23.9% had received prior bleeding control training. Participants who reported feeling ‘extremely confident’ responding to an emergency medical situation rose from 68.2% prior to StB training to 94.3% post-training. Regarding hemorrhage control abilities, 37.5% felt extremely confident before the training, compared with 95.5% after the training. For wound packing and tourniquet application, 44.3% and 53.4%, respectively, felt extremely confident pre-training, followed by 97.7% for both skills post-training. Importantly, 90.9% of StB trainees felt comfortable teaching newly acquired hemorrhage control skills. A significant majority of participants said that confidence in their wound packing and tourniquet skills would improve with more realistic mannequins.

Conclusion

To our knowledge, this is the first StB training in India. Disparities in access to care, long transport times, and insufficient numbers of prehospital personnel contribute to its significant trauma burden. Dissemination of these critical life-saving skills into this region and the resulting civilian interventions will increase the number of trauma patients who survive long enough to reach a trauma center. Additionally, considerations should be given to translating the course into local languages to increase program reach.

Level of Evidence

Level IV.

Forebrain-Specific Transgene Rescue of 11β-HSD1 Associates with Impaired Spatial Memory and Reduced Hippocampal Brain-Derived Neurotrophic Factor mRNA Levels in Aged 11β-HSD1 Deficient Mice

Mice lacking the intracellular glucocorticoid-regenerating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) are protected from age-related spatial memory deficits. 11β-HSD1 is expressed predominantly in the brain, liver and adipose tissue. Reduced glucocorticoid levels in the brain in the absence of 11β-HSD1 may underlie the improved memory in aged 11β-HSD1 deficient mice. However, the improved glucose tolerance, insulin sensitisation and cardioprotective lipid profile associated with reduced peripheral glucocorticoid regeneration may potentially contribute to the cognitive phenotype of aged 11β-HSD1 deficient mice. In the present study, transgenic mice with forebrain-specific overexpression of 11β-HSD1 (Tg) were intercrossed with global 11β-HSD1 knockout mice (HSD1KO) to examine the influence of forebrain and peripheral 11β-HSD1 activity on spatial memory in aged mice. Transgene-mediated delivery of 11β-HSD1 to the hippocampus and cortex of aged HSD1KO mice reversed the improved spatial memory retention in the Y-maze but not spatial learning in the watermaze. Brain-derived neurotrophic factor (BDNF) mRNA levels in the hippocampus of aged HSD1KO mice were increased compared to aged wild-type mice. Rescue of forebrain 11β-HSD1 reduced BDNF mRNA in aged HSD1KO mice to levels comparable to aged wild-type mice. These findings indicate that 11β-HSD1 regenerated glucocorticoids in the forebrain and decreased levels of BDNF mRNA in the hippocampus play a role in spatial memory deficits in aged wild-type mice, although 11β-HSD1 activity in peripheral tissues may also contribute to spatial learning impairments in aged mice.

Short-term inhibition of 11β-hydroxysteroid dehydrogenase type 1 reversibly improves spatial memory but persistently impairs contextual fear memory in aged mice

High glucocorticoid levels induced by stress enhance the memory of fearful events and may contribute to the development of anxiety and posttraumatic stress disorder. In contrast, elevated glucocorticoids associated with ageing impair spatial memory. We have previously shown that pharmacological inhibition of the intracellular glucocorticoid-amplifying enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) improves spatial memory in aged mice. However, it is not known whether inhibition of 11β-HSD1 will have any beneficial effects on contextual fear memories in aged mice. Here, we examined the effects of UE2316, a selective 11β-HSD1 inhibitor which accesses the brain, on both spatial and contextual fear memories in aged mice using a vehicle-controlled crossover study design.

Short-term UE2316 treatment improved spatial memory in aged mice, an effect which was reversed when UE2316 was substituted with vehicle. In contrast, contextual fear memory induced by foot-shock conditioning was significantly reduced by UE2316 in a non-reversible manner. When the order of treatment was reversed following extinction of the original fear memory, and a second foot-shock conditioning was given in a novel context, UE2316 treated aged mice (previously on vehicle) now showed increased fear memory compared to vehicle-treated aged mice (previously on UE2316). Renewal of the original extinguished fear memory triggered by exposure to a new environmental context may explain these effects. Thus 11β-HSD1 inhibition reverses spatial memory impairments with ageing while reducing the strength and persistence of new contextual fear memories. Potentially this could help prevent anxiety-related disorders in vulnerable elderly individuals.

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Aged mice were treated with UE2316 using a vehicle-controlled crossover design.

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Short-term UE2316 treatment improves spatial memory in a reversible manner.

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Contextual fear memory retention was impaired with UE2316.

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Contextual fear memory effects persisted following reversal of treatment.