Clinical experience with the Medpor porous polyethylene implant

Submucosal Trans-Septal Suturing Technique After a Septal Extension Graft with Porous High-Density Polyethylene: A Technical Report

BACKGROUND

Porous high-density polyethylene (pHDPE) is an alternative material for a septal extension graft (SEG) in oriental rhinoplasty when autologous cartilage is limited. Although nasal packing (NP) and trans-septal suturing (TSS) techniques are routine procedures to obviate the dead space after septoplasty, they are associated with certain discomforts and complications.

OBJECTIVE

To investigate the application of a submucosal trans-septal suturing (STSS) technique after SEG with pHDPE.

METHODS

A prospective study was conducted on 60 female participants who underwent SEG with pHDPE. The participants were randomly divided into the NP group and STSS group. The extra surgical duration of NP and STSS, pain, nasal obstruction, and sleeping disturbance as well as postoperative complications were recorded and compared between groups.

RESULTS

No significant difference was found between group NP and group STSS in terms of mean age. The mean extra surgical duration of group STSS was significantly longer than group NP. There were significant higher pains of group NP at 24 hours and 48 hours postoperatively, compared with group STSS. The NP group also experienced significantly more nasal obstruction and sleep disturbance within 48h postoperatively compared to the STSS group. There was one infection in each group, minor bleeding in two NP patients, and one STSS patient. There was no major bleeding, hematoma, graft exposure, or septal perforation in both groups.

CONCLUSION

Although STSS needs a longer extra surgical duration than NP, it significantly improves the patient's postoperative comfort with a faster return to normal respiration compared to NP.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Polycaprolactone Fiber and Laminin and Collagen IV Protein Incorporation in Implants Enhances Wound Healing in a Novel Mouse Skin Splint Model

Wound healing is an intricate process involving multiple cells and distinct phases, presenting challenges for comprehensive investigations. Currently available treatments for wounds have limited capacity to fully restore tissue and often require significant investments of time in the form of repetitive dressing changes and/or reapplications. This article presents a novel study that aims to enhance wound healing by developing biomaterial scaffolds using Medpor®, a porous polyethylene implant, as a model scaffold. The study incorporates electrospun poly(e-caprolactone) (PCL) fibers and a protein mixture (PM) containing collagen IV and laminin onto the Medpor® scaffolds. To evaluate the impact of these implants on wound healing, a unique splinted wound model in mice is employed. The wounds were evaluated for closure, inflammation, collagen deposition, angiogenesis, epithelialization, and proliferation. The results show that wounds treated with Medpor® + PCL + PM implants demonstrate accelerated closure rates, improved epithelialization, and enhanced angiogenesis compared to other implant groups. However, there were no significant differences observed in collagen deposition and inflammatory response among the implant groups. This study provides valuable insights into the potential benefits of incorporating PCL fibers and a PM onto scaffolds to enhance wound healing. Furthermore, the developed splinted wound model with integrated implants offers a promising platform for future studies on implant efficacy and the advancement of innovative wound healing strategies.

Unveiling the safety landscape: A comprehensive review of the toxicological profile of facial aesthetic implants and biomaterials

Exploring diverse biomaterials and implants in the ear, nose, and throat by understanding adverse effects and post-usage events. Literature was obtained from Scopus, PubMed, Google Scholar, and Web of Science. A comprehensive analysis was conducted on original research studies, case reports, and case series spanning from December 2010 to May 2022. Our analysis underscores that the effectiveness of cochlear implants (CIs) relies on factors such as biocompatibility, anti-inflammatory measures, and fibrosis reduction. Although silicone is employed in otologic applications, allergic reactions leading to CI extrusion are rare. In the context of partial ossicular replacement prostheses or total ossicular replacement prostheses, polyethylene grafts (Teflon) are utilized, and Nitinol-pistons are employed in stapedotomy, with adverse consequences encompassing graft extrusion and residual perforation. Chronic sphenoid sinusitis is linked to the use of Medpor porous polyethylene implants in sellar reconstruction during skull-based surgeries. Injectable collagen preparations in vocal cord paralysis lead to submucosal deposits and resultant dysphonia. Montgomery T-tubes are employed for subglottic stenosis but are associated with granulation tissue formation. Metallic tracheostomy tubes give rise to secondary foreign bodies, and double-lumen tracheostomy tubes are prone to biofilm formation. Despite numerous research studies, there remains a necessity for the refinement of implant designs to mitigate complications and enhance the overall quality of life for patients.

Auricle reconstruction with autologous costal cartilage versus polyethylene implants in microtia patients: a meta-analysis

BACKGROUND

Auricle reconstruction is among the most challenging procedures in plastic and reconstructive surgery, and the choice of framework material is a critical decision for both surgeons and patients. This meta-analysis compared the outcomes of autologous auricle reconstruction using costal cartilage with those of alloplastic reconstruction using porous polyethylene implants.

METHODS

A literature review was conducted using the PubMed and Embase databases to retrieve articles published between January 2000 and June 2024. The outcomes analyzed included postoperative complications such as framework exposure, infection, skin necrosis, hematoma, and hypertrophic scars, as well as patient satisfaction. The proportions of reconstructive outcomes from each selected study were statistically analyzed using the "metaprop" function in R software.

RESULTS

Fourteen articles met our inclusion criteria. The group undergoing polyethylene implant reconstruction exhibited higher rates of framework exposure, infection, and skin necrosis, whereas the autologous reconstruction group experienced higher rates of hematoma and hypertrophic scars. Of all the complications, framework exposure was the only one to show a statistically significant difference between the two groups (p < 0.0001). In terms of patient satisfaction, those who underwent autologous cartilage reconstruction reported a higher rate of satisfaction, although this difference did not reach statistical significance in the meta-analysis (p = 0.076).

CONCLUSION

There is no statistically significant difference in postoperative complications such as infection, hematoma, skin necrosis, and hypertrophic scars between auricle reconstructions using autologous costal cartilage and those using polyethylene implants. However, reconstructions with polyethylene implants show a significantly higher rate of framework exposure.

Custom-Made Implant Fabrication for Chin Augmentation Using Piled-Up Expanded Polytetrafluoroethylene Sheets: An Innovative Surgical Technique and Literature Review

BACKGROUND

Alloplastic chin augmentation is the most common esthetic surgical treatment to reshape the chin. However, factory-made chin implants are typically standardized rather than custom-made and have potential to cause complications. Although the fabrication of custom-made implants by using computer-assisted planning and 3D-printing technology has become widespread, the process has several disadvantages, including long preoperative prosthesis preparation times, high costs, and unsuitability for patients with asymmetric chins or those who undergo combined mandibuloplasty before implant placement. The present study developed an innovative chin augmentation technique involving stacked expanded polytetrafluoroethylene (e-PTFE) sheets that is suitable for most patients and has minimal side effects.

MATERIALS AND METHODS

A retrospective review of a single surgeon's experience was performed over a 2 year period for patients who underwent a procedure involving piled-up e-PTFE sheets for alloplastic chin augmentation. This study analyzed the outcomes, complications (temporary nerve numbness, wound infection, hematoma formation, and implant displacement), and patient satisfaction during follow-up.

RESULTS

Between January 2018 and December 2020, 38 patients underwent the procedure involving piled-up e-PTFE sheets for alloplastic chin augmentation. Six patients (15.8%) experienced nerve-related temporary numbness, and one (2.6%) experienced wound infection. None had developed major complications such as implant displacement or wound infection at follow-up. Moreover, the patients demonstrated a high level of satisfaction with the surgical results.

CONCLUSION

Piled-up e-PTFE sheets can be used to produce custom-fit porous polyethylene chin implants that result in minimal complications and a very high satisfaction rate.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Surgical Correction of Cicatricial Lower Eyelid Retraction: A Systematic Review

BACKGROUND

Cicatricial lower eyelid retraction is a challenging condition. It involves scarring of the lower eyelid, which causes it to retract and expose the sclera. This can lead to complications such as dry eye syndrome and corneal melting. It can be caused by trauma, burns, or previous eyelid surgery. Detailed assessment and understanding of eyelid anatomy and retraction are critical for successful surgical planning. Dynamic and static examinations of the eyelid including measurements of the lower eyelid margin reflex distance (MRD2) and scleral show are also essential to determine the appropriate treatment approach.

METHODS

A systematic review was conducted using Medline, Scopus, and Cochrane databases with keywords related to cicatricial lower eyelid retraction. The publication language was limited to English after 2000. A total of 29 articles were included for data extraction and analysis.

RESULTS

The main surgical techniques include tarsoconjunctival grafts, spacers, midface lift, and lateral canthal tendon suspension, although no single procedure has been universally recognized as the gold standard. New innovations such as synthetic grafts and xenografts are being explored for their potential in eyelid reconstruction. Severe cases, defined as those with inferior scleral show greater than 2 mm, may require a combination of reconstruction methods.

CONCLUSIONS

Correcting cicatricial lower eyelid retraction is a major challenge in oculoplastic reconstruction. The surgical approach should be individualized, considering the pathologies and etiologies of lid retraction. In-depth knowledge and careful surgical planning are essential for best outcomes. There is no gold standard technique, and postoperative outcomes, complications, and management vary depending on the surgical approach used.

Application of a Single T-Shaped Porous High-Density Polyethylene in Oriental Nasal Tip-Plasty

Porous high-density polyethylene (pHDPE) is an alternative material for septal extension grafts. This study investigated the clinical application of a single T-shaped pHDPE graft combined with auricular cartilage in oriental nasal tip-plasty. A retrospective analysis was conducted of 66 patients who underwent septal extension graft with a T-shaped pHDPE and auricular cartilage graft from December 2018 to November 2021. All patients were female from 19 to 51 years old (average: 28.9 years). Patients were followed up for 5 to 40 months with an average of 23.8 months. The postoperative nasal length (39.8±3.7 mm) was significantly improved (35.6±5.7 mm preoperatively, P <0.0001) with the tip projection increasing from 23.9±2.3 mm preoperatively to 25.3±2.4 mm postoperatively ( P =0.0005). There was a significant difference in the nasolabial angle (96.8±14.1 degrees preoperatively versus 101.8±7.2 degrees postoperatively, P =0.0105) but no significant change in the nasofrontal angle (143.3±9.5 degrees preoperatively versus 143.7±5.5 degrees postoperatively, P =0.7546), with an improved tip projection achieved in 93.9% of patients. One patient had an abscess in the nasal septum and a tip graft was performed using auricular cartilage in another patient because of an insufficient postoperative tip projection. There was a slight tip deviation in 2 patients, 1 case of a deviated nasal tip was corrected with a pHDPE sheet graft, while the other was left intact. Two patients had excess cartilaginous graft protruding to the nasal cavity that did not affect nasal ventilation and the shape of the nasal tip was relatively good, so the prominent cartilaginous graft was not addressed. In conclusion, this technique not only improved the bulbous nasal tip, lengthened the short nose, and increase the tip projection, but also prevented absorption of the existing septal cartilage and reduced infection or extrusion of the pHDPE.

Complications Following Alloplastic Chin Augmentation: A Systematic Review of Implant Materials and Surgical Techniques

BACKGROUND

Alloplastic implantation has become a popular method of chin augmentation. Historically, silicone was the most commonly used implant, but porous materials have grown in favor due to improved fibrovascularization and stability. Nevertheless, it is unclear which implant type has the most favorable complication profile. This systematic review aims to compare the complications of published chin implants and surgical approaches to provide data-driven recommendations for optimizing chin augmentation outcomes.

METHODS

The PubMed® database was queried on March 14, 2021. We selected studies reporting data on alloplastic chin augmentation excluding additional procedures such as osseous genioplasty, fat grafting, autologous grafting, and fillers. The following complications were extracted from each article: malposition, infection, extrusion, revision, removal, paresthesias, and asymmetry.

RESULTS

Among the 39 articles analyzed, the year of publication ranged from 1982 to 2020; additionally, 31 were retrospective case series, 5 were retrospective cohort or comparative studies, 2 were case reports, and 1 was a prospective case series. More than 3104 patients were included. Among the 11 implants reported, the 3 implants with the highest number of publications were silicone, high-density porous polyethylene (HDPE), and expanded polytetrafluoroethylene (ePTFE). Silicone demonstrated the lowest rates of paresthesias (0.4%) compared to HDPE (20.1%, P < 0.01) and ePTFE (3.2%, P < 0.05). In contrast, there were no statistically significant differences in rates of implant malposition, infection, extrusion, revision, removal, or asymmetry when stratified by implant type. Various surgical approaches were also documented. Compared with subperiosteal implant placement, the dual-plane technique demonstrated higher rates of implant malposition (2.8% vs 0.5%, P < 0.04), revision (4.7% vs 1.0%, P < 0.001), and removal (4.7% vs 1.1%, P < 0.01), but a lower incidence of paresthesias (1.9% vs. 10.8%, P < 0.01). Compared with extraoral incisions, intraoral incisions resulted in higher rates of implant removal (1.5% vs 0.5%, P < 0.05) but lower rates of asymmetry (0.7% vs 7.5%, P < 0.01).

CONCLUSION

Silicone, HDPE, and ePTFE had low overall complication rates, demonstrating an acceptable safety profile regardless of implant selection. Surgical approach was found to significantly influence complications. Additional comparative studies on surgical approach while controlling for implant type would be beneficial for optimizing alloplastic chin augmentation practices.

3D-printed high-density polyethylene scaffolds with bioactive and antibacterial layer-by-layer modification for auricle reconstruction

High-density polyethylene (HDPE) is a promising material for the development of scaffold implants for auricle reconstruction. However, preparing a personalized HDPE auricle implant with favorable bioactive and antibacterial functions to promote skin tissue ingrowth is challenging. Herein, we present 3D-printed HDPE auricle scaffolds with satisfactory pore size and connectivity. The layer-by-layer (LBL) approach was applied to achieve the improved bioactive and antibacterial properties of these 3D printed scaffolds. The HDPE auricle scaffolds were fabricated using an extrusion 3D printing approach, and the individualized macrostructure and porous microstructure were both adjusted by the 3D printing parameters. The polydopamine (pDA) coating method was used to construct a multilayer ε-polylysine (EPL) and fibrin (FIB) modification on the surface of the 3D HDPE scaffold via the LBL self-assembly approach, which provides the bioactive and antibacterial properties. The results of the in vivo experiments using an animal model showed that LBL-coated HDPE auricular scaffolds were able to significantly enhance skin tissue ingrowth and ameliorate the inflammatory response caused by local stress. The results of this study suggest that the combination of the 3D printing technique and surface modification provides a promising strategy for developing personalized implants with biofunctional coatings, which show great potential as a scaffold implant for auricle reconstruction applications.

Management Options for Linear Scleroderma ("En Coup de Sabre")

BACKGROUND

En coup de sabre (ECDS) is a form of linear-scleroderma, primarily affecting the face. Despite effectiveness of pharmacological interventions in the management of lesions, sequelae of cutaneous deformities are common.

OBJECTIVE

Review the existing surgical tools for the correction of "en coup de sabre" ECDS lesions and facial deformities.

MATERIALS AND METHODS

The authors conducted a literature search for reports on surgical interventions for ECDS deformations, in the electronic databases of PubMed, Scopus, and Cochrane Library Databases.

RESULTS

Twenty-six publications reporting 39 patients were found in the literature. The average age of patients was 25 ± 4.7 years. Thirty-one of the patients were females. Six methods were found in the literature for surgical correction of ECDS. Fat grafting was performed in 41% of patients, surgical reconstruction in 18%, injectable fillers in 15%, implants in 10%, botulinum toxin injections in 8%, and bone/cartilage grafts in 8%. Imaging studies of the skull and face were performed in 36% of patients. Bony defects were found in 64.3% of them.

CONCLUSION

Different surgical and minimally invasive options exist in the armamentarium of clinicians correcting ECDS deformities. Tailoring the method of correction to patient's needs and expectation is crucial in ensuring patient satisfaction.

Current Practices in Dorsal Augmentation Rhinoplasty

BACKGROUND

Dorsal augmentation rhinoplasty addresses the aesthetic and functional impairments caused by a deficient nasal dorsum. Augmentation rhinoplasty can be performed using a variety of different surgical techniques and grafting materials that all have distinct advantages and disadvantages.

METHODS

Grafting materials have unique characteristics, uses, and safety profiles. A detailed overview of various grafting materials and their uses, risks, and benefits is provided.

RESULTS

Autologous grafting materials include septal cartilage, auricular cartilage, and costal cartilage. These donor sites can provide various amounts of en bloc or diced cartilage. Alternatively, bone may be used when strong structural stability is required, and soft tissue may be used to fill mild to moderate defects. Homologous grafts (e.g., irradiated and nonirradiated rib) and acellular dermal matrices are alternatives to autologous graft with many similar advantages and no need for an additional surgical site. Lastly, alloplastic implants may be successfully used for dorsal augmentation if both patient and surgeon understand their associated risks.

CONCLUSION

To perform successful dorsal augmentation, surgeons should be familiar with the wide variety of operative approaches and augmentation materials that are currently available and understand their risks, benefits, and uses.

Facial Masculinization from Procedures to Payment: A Review

As the demand for gender-affirming procedures continues to increase, patients and providers have a greater imperative to understand the current state of facial masculinization. Facial reconstruction for transgender women has been shown to treat gender dysphoria effectively and reduce rates of discrimination and victimization. Although facial masculinization surgery for transgender men is less common, there are multiple surgical and nonsurgical options to supplement the effect of hormone therapy on facial appearance, including but not limited to: receding the hair line, flattening the forehead, expanding the supraorbital ridge, increasing the dorsal nasal projection, squaring the jaw, and augmenting the chin. This review aims to summarize these techniques for providers who wish to inform transgender male patients about their options and discuss them in the context of patient satisfaction and availability of insurance coverage.

Complications of Alloplast Rhinoplasty and Their Management: A Comprehensive Review

In Asian countries, augmentation rhinoplasty is especially common, where alloplastic implants are used much more commonly than autologous tissues. In rhinoplasty, such artificial materials include silicone, expanded polytetrafluoroethylene (ePTFE), porous high-density polyethylene (pHDPE), and acellular human dermis. As the use of implants has become increasingly common in rhinoplasty, more adverse effects such as infection, extrusion, movement, irregularities, absorption, prolonged swelling, seroma, and contracture have been recognized and reported in the literature. Surgeons should be able to recognize these probable complications and manage them successfully. Early detection and prompt management of the complication are essential for minimizing the severity of the deformity. Proper management of complications is key for the success of dorsal augmentation using alloplastic implants.

Sino-Cutaneous Fistula After Using Medpor Implant in Orbital Blowout Fracture

In surgical repair of orbital fracture, implant materials play an important role in restoring the functional and anatomic structure of the orbit. Alloplastic implant materials are widely used for this surgery, but they have the risk of complications such as infections, pain, and extrusion. Because they are artificial implants, infection can occur more than autologous implants and is the most challenging problem to manage. Sino-cutaneous fistula is a rare complication of chronic sinusitis and it can be caused by this implant materials. The authors report a case of formation of sino-cutaneous fistula after using Medpor (Stryker Co, MI) implant in orbital blowout fracture repair.

Outcomes and complications associated with malar onlays: literature review and case series of 119 implants

Alloplastic malar onlays have been used by surgeons to correct or enhance the midfacial skeleton for over 40 years. Case series have shown respectable results using different alloplastic materials in various maxillofacial subsites. However, these articles include small numbers of patients with limited follow up. We present a literature review specifically concentrating on porous polyethylene (Medpor, Stryker) and polyethyl ether ketone (PEEK) malar onlays. We illustrate the technique used by a single oral and maxillofacial surgeon for placement of 119 implants in 61 patients over a 14-year period, and show the results of this work with long-term follow up. A complication rate of 2.5% in this cohort was reported, with follow up of three years, demonstrating that this technique for midfacial correction is successful in both the short and the long term.

Coating Medpor® Implant with Tissue-Engineered Elastic Cartilage

Inert biomaterials used for auricular reconstruction, which is one of the most challenging and diverse tasks in craniofacial or head and neck surgery, often cause problems such as capsule formation, infection, and skin extrusion. To solve these problems, scaffold consisting of inert biomaterial, high-density polyethylene (Medpor^®) encapsulated with neocartilage, biodegradable poly(DL-lactic-co-glycolic acid) (PLGA) was created using a tissue engineering strategy. PLGA scaffold without Medpor^® was created to serve as the control. Scaffolds were vacuum-seeded with rabbit chondrocytes, freshly isolated from the ear by enzymatic digestion. Then, cell-seeded scaffolds were implanted subcutaneously in the dorsal pockets of nude mice. After 12 weeks, explants were analyzed by histological, biochemical, and mechanical evaluations. Although the PLGA group resulted in neocartilage formation, the PLGA-Medpor^® group demonstrated improved outcome with the formation of well-surrounded cartilage around the implants with higher mechanical strength than the PLGA group, indicating that Medpor^® has an influence on the structural strength of engineered cartilage. The presence of collagen and elastin fibers was evident in the histological section in both groups. These results demonstrated a novel method of coating implant material with engineered cartilage to overcome the limitations of using biodegradable scaffold in cartilage tissue regeneration. By utilizing the patient's own chondrocytes, our proposed method may broaden the choice of implant materials while minimizing side effects and immune reaction for the future medical application.

Evaluation of tissue ingrowth and reaction of a porous polyethylene block as an onlay bone graft in rabbit posterior mandible

Purpose

A new form of porous polyethylene, characterized by higher porosity and pore interconnectivity, was developed for use as a tissue-integrated implant. This study evaluated the effectiveness of porous polyethylene blocks used as an onlay bone graft in rabbit mandible in terms of tissue reaction, bone ingrowth, fibrovascularization, and graft-bone interfacial integrity.

Methods

Twelve New Zealand white rabbits were randomized into 3 treatment groups according to the study period (4, 12, or 24 weeks). Cylindrical specimens measuring 5 mm in diameter and 4.5 mm in thickness were placed directly on the body of the mandible without bone bed decortication, fixed in place with a titanium screw, and covered with a collagen membrane. Histologic and histomorphometric analyses were done using hematoxylin and eosin-stained bone slices. Interfacial shear strength was tested to quantify graft-bone interfacial integrity.

Results

The porous polyethylene graft was observed to integrate with the mandibular bone and exhibited tissue-bridge connections. At all postoperative time points, it was noted that the host tissues had grown deep into the pores of the porous polyethylene in the direction from the interface to the center of the graft. Both fibrovascular tissue and bone were found within the pores, but most bone ingrowth was observed at the graft-mandibular bone interface. Bone ingrowth depth and interfacial shear strength were in the range of 2.76-3.89 mm and 1.11-1.43 MPa, respectively. No significant differences among post-implantation time points were found for tissue ingrowth percentage and interfacial shear strength (P>0.05).

Conclusions

Within the limits of the study, the present study revealed that the new porous polyethylene did not provoke any adverse systemic reactions. The material promoted fibrovascularization and displayed osteoconductive and osteogenic properties within and outside the contact interface. Stable interfacial integration between the graft and bone also took place.

Biomimetic UHMWPE/HA scaffolds with rhBMP-2 and erythropoietin for reconstructive surgery

A promising direction for the replacement of expanded bone defects is the development of bioimplants based on synthetic biocompatible materials impregnated with growth factors that stimulate bone remodeling. Novel biomimetic highly porous ultra-high molecular weight polyethylene (UHMWPE)/40% hydroxyapatite (HA) scaffold for reconstructive surgery with the porosity of 85 ± 1% vol. and a diameter of pores in the range of 50-800 μm was developed. The manufacturing process allowed the formation of trabecular-like architecture without additional solvents and thermo-oxidative degradation. Biomimetic UHMWPE/HA scaffold was biocompatible and provided effective tissue ingrowth on a model of critical-sized cranial defects in mice. The combined use of UHMWPE/HA with Bone Morphogenetic Protein-2 (BMP-2) demonstrated intensive mineralized bone formation as early as 3 weeks after surgery. The addition of erythropoietin (EPO) significantly enhanced angiogenesis in newly formed tissues. The effect of EPO of bacterial origin on bone tissue defect healing was demonstrated for the first time. The developed biomimetic highly porous UHMWPE/HA scaffold can be used separately or in combination with rhBMP-2 and EPO for reconstructive surgery to solve the problems associated with difference between implant architecture and trabecular bone, low osteointegration and bioinertness.

Correction of the Over-resected Nose

Overzealous reduction during rhinoplasty may result in manifold functional as well as aesthetic injuries to the nose and is a prevailing antecedent of revision rhinoplasty. Although challenges for the revision rhinoplasty surgeon abound, careful assessment of the anatomic deficiencies of the nose, accurate evaluation and management of a patient's expectations, and precise planning and execution of surgical technique serve to facilitate a successful result. Contemporary techniques for correction of the over-resected nose are discussed, with special attention directed toward costal cartilage grafting and diced cartilage fascia techniques.

Design and fabrication of a hybrid alginate hydrogel/poly(ε-caprolactone) mold for auricular cartilage reconstruction

The aim of this study was to design and manufacture an easily assembled cartilage implant model for auricular reconstruction. First, the printing accuracy and mechanical properties of 3D-printed poly-ε-caprolactone (PCL) scaffolds with varying porosities were determined to assess overall material properties. Next, the applicability of alginate as cell carrier for the cartilage implant model was determined. Using the optimal outcomes of both experiments (in terms of (bio)mechanical properties, cell survival, neocartilage formation, and printing accuracy), a hybrid auricular implant model was developed. PCL scaffolds with 600 μm distances between strands exhibited the best mechanical properties and most optimal printing quality for further exploration. In alginate, chondrocytes displayed high cell survival (~83% after 21 days) and produced cartilage-like matrix in vitro. Alginate beads cultured in proliferation medium exhibited slightly higher compressive moduli (6 kPa) compared to beads cultured in chondrogenic medium (3.5 kPa, p > .05). The final auricular mold could be printed with 300 μm pores and high fidelity, and the injected chondrocytes survived the culture period of 21 days. The presented hybrid auricular mold appears to be an adequate model for cartilage tissue engineering and may provide a novel approach to auricular cartilage regeneration for facial reconstruction. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1711-1721, 2019.

Recommendations for the Development and Reform of Microtia and Atresia Services

BACKGROUND

The initial step in setting up standardized microtia-atresia service is investigating the current status of the service and comparing this to internationally recognized guidelines or care standards. In many countries, documented information about microtia care is lacking. This study is an initiative to guide reform efforts of national microtia service in any country. The UK care standards for microtia-atresia can be a useful model to help set up a comprehensive microtia-atresia service.

METHODS

The authors conducted a survey to investigate different aspects of microtia service in Egypt. The major plastic surgery centers (n = 22) were surveyed by a structured questionnaire. The results were compared with the UK care standards for microtia-atresia to identify the aspects that need improvement. Thorough analysis of the main problems in microtia-atresia service is presented.

RESULTS

The authors found that microtia service is fragmented between the surveyed centers with 65% of the centers treating less than 10 microtia cases annually. Multiple surgeons are responsible for ear reconstruction in 90% of centers and only 25% of them practise a multidisciplinary team approach. None of the centers uses validated tools of aesthetic or psychological patient-reported outcome measures.

RECOMMENDATIONS

These 5 recommendations are the keys to reforming microtia service in any country:(1) Establishing nationally designated centers to concentrate the required expertise.(2) Assigning fewer high-volume surgeons to optimize the surgical outcomes.(3) Providing treatment by experienced multidisciplinary teams.(4) Using validated tools of patient-reported outcome measures.(5) Collecting and keeping standardized records for regular audit and intercenter studies.

Alloplastic Facial Implants: A Systematic Review and Meta-Analysis on Outcomes and Uses in Aesthetic and Reconstructive Plastic Surgery

BACKGROUND

Alloplastic materials in facial surgery have been used successfully for various applications in the reconstructive restoration or aesthetic augmentation of the facial skeleton. The objective of this study was to conduct a comprehensive systematic review of alloplastic implant materials utilized to augment the facial skeleton stratified by anatomical distribution, indication, specific material used, and respective outcomes.

METHODS

A comprehensive systematic review on alloplastic facial implant data was conducted utilizing Medline/PubMed database. Articles were stratified by (1) anatomic localization in the face, as well as (2) alloplastic material.

RESULTS

A total of 17 studies (n = 2100 patients, follow-up range = 1 month-27 years) were included. Overall, mersilene mesh implants were associated with the highest risk of infection (3.38%). Methyl methacrylate implants were associated with the highest rate of hematoma (5.98%). Implants placed in the malar region (2.67%) and frontal bones (2.50%) were associated with the highest rates of infection. Implants placed in the periorbital region were associated with the highest rate of inflammation (8.0%), explantation (8.0%), and poor cosmetic outcome (17.0%). Porous implants were shown to be more likely to potentiate infection than non-porous implant types.

CONCLUSIONS

Alloplastic facial implants are a reliable means of restoring facial symmetry and achieving facial skeletal augmentation with a relatively low complication profile. It is important for plastic surgeons to understand the relative risks for each type of implant to develop postoperative complications or poor long-term cosmetic results. Interestingly, porous implants were shown to be more likely to potentiate infection than non-porous implant types.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Craniofacial Microsomia

Clinicians use different diagnostic terms for patients with underdevelopment of facial features arising from the embryonic first and second pharyngeal arches, including first and second branchial arch syndrome, otomandibular dysostosis, oculoauriculovertebral syndrome, and hemifacial microsomia. Craniofacial microsomia has become the preferred term. Although no diagnostic criteria for craniofacial microsomia exist, most patients have a degree of underdevelopment of the mandible, maxilla, ear, orbit, facial soft tissue, and/or facial nerve. These anomalies can affect feeding, compromise the airway, alter facial movement, disrupt hearing, and alter facial appearance.

Extent of Inflammation and Foreign Body Reaction to Porous Polyethylene In Vitro and In Vivo

BACKGROUND/AIM

High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo.

MATERIALS AND METHODS

Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines.

RESULTS

Cells showed a significantly decreased proliferation (p<0.001) after 48 h and a significantly increased expression of TNF-α (p<0.05) at 24, 48 and 72 h. All animals showed foreign body cell reactions and signs of chronic inflammation. Expression of all but one of the investigated cytokines dropped to non-significant levels after an initial increase.

CONCLUSION

Application of porous polyethylene can cause local chronic inflammatory reactions. Although clinical application seems to be immunologically safe, indication and risks should be evaluated carefully when using PP implants.

Causes of the Removal of High-Density Polyethylene Sheets (Medpor) in Revision Rhinoplasty

The aim of this study was to identify the causes of complications in rhinoplasties using Medpor. The medical records of 71 patients who had undergoing a reoperation after a rhinoplasty using Medpor were reviewed. From each patient's history, examination records, and operative records, the method of the previous rhinoplasty using Medpor was extracted. The previously inserted Medpor and the septal mucosa covering it were removed during the reoperation and observed in 3 cases. A turned-up or short nose (43.8%) and tip stiffness (25.3%) were significantly more common than other complaints (P < 0.05). The strut type (49.2%) and the septal extension type (43.8%) were significantly more common than the spreader type (P < 0.001). In the reoperation, extension grafts (47.1%) and by tip grafts (39.7%) were significantly more common than other procedures (P < 0.001). Grossly, the specimens were covered with septal mucosa and multiple ball-like granulation tissues (cobblestone appearance) at the "pores" of the Medpor. Microscopically, Medpor was covered with fibrous collagenous tissue, partially bridging through the pores. Inflammatory cells had infiltrated around the polyethylene. The authors classify the patients in the present series as: those with a long columella strut to the anterior nasal spine, those with Medpor inserted onto the membranous septum (septal extension graft or too large), and those with Medpor used as spreader graft covered with nasal mucosa (causing weakness of the nasal septum and thinning or necrosis of the mucosa). Using Medpor as a strut graft seems to be relatively safe if the floating type is used.

Microtia and Related Facial Anomalies

Infants may be born with external ear deformities or malformations that can present a diagnostic clue to an affiliated syndrome while also presenting the possibility of surgical intervention. Microtia is a malformation of the ear that is associated with other craniofacial or systemic anomalies in 50% of cases. Surgical correction of microtia and associated facial anomalies is complex and must be integrated thoughtfully into the overall care plan for children with complex medical needs. Familiarity with types of ear and facial anomalies and their association with more global concerns can allow perinatal practitioners to better serve their patients.

Auricular Reconstruction Using Porous Polyethylene Implant Technique

Alloplast-based ear reconstruction has become more popular over the years because it offers many advantages compared with the traditional staged autologous costal cartilage approach. Advantages include earlier reconstruction in the setting of microtia, fewer procedures, less donor site morbidity, shorter surgeon learning curve, and improved consistency in the final aesthetic result. Although other implantable materials have been used in auricular reconstruction with variable success, porous high-density polyethylene frameworks combined with recent advances in the creation of the soft tissue coverage have significantly improved outcomes with minimal complications and long-term viability. This article describes the authors' technique.

Early Experience With Nonporous Polyethylene Barrier Sheet in Orbital Fracture Repair

PURPOSE

The aim of this study was to evaluate the efficacy of the nonporous polyethylene barrier sheet as an alternative for nylon foil (SupraFOIL) implants in repair of orbital fractures.

METHODS

This is a prospective, case series using the Stryker 0.4-mm-thick nonporous polyethylene barrier sheet in all patients over the age of 18 years presenting with orbital fractures from December 2014 to June 2015. Patient's age, location of fracture, etiology of injury, presence of preoperative restriction and diplopia, and postoperative diplopia and/or enophthalmos was recorded. Institutional review board approval was received, and consent was obtained from all participants. Patients were followed for at least 6 months when possible. Scanning electron microscopy was used to compare the thickness, surface characteristics, and porosity of the nonporous polyethylene barrier and nylon foil implants. Beam deflection testing was also performed to compare the biomechanical properties of each implant.

RESULTS

Forty-six patients who underwent repair of orbital fractures with the nonporous polyethylene barrier sheet were included in this series. Average age was 43.3 years (range: 18-84 years). Twenty-six of 46 patients (56.5%) were males, and 20 (43.4%) were females. The most common causes of injuries were assault (38.3%), falls (25.5%), motor vehicle accident (14.9%), and sports related (10.5%). Twenty of 46 patients (43.4%) had isolated orbital floor, and 2 patients (4.3%) had isolated medial wall fractures. Fifteen patients (32.6%) had combined floor and medial wall fractures involving the inferomedial orbital strut, and 9 (19.6%) had floor fractures associated with zygomaticomaxillary complex or lateral wall fractures. Twenty-eight patients (60.9%) had preoperative diplopia. Timing of surgery was between 3 and 55 days, with the median of 11.5 days. Five of 46 patients (10.8%) had residual diplopia at their 1-week postoperative visit, 4 of those patients' diplopia had resolved at 2 months postoperatively. One patient had residual diplopia at 6-month follow up. Electron microscopy showed that the 0.4-mm nonporous polyethylene barrier implant was thinner (0.33 mm) than expected and thinner than 0.4-mm SupraFOIL (0.38 mm). Scanning electron microscopy exhibited that the surface of the nonporous polyethylene barrier was smooth and nonporous. Beam deflection testing showed that for small forces (<100 mN), the 2 materials behaved nearly identically, but at higher forces, the nonporous polyethylene implant exhibited less stiffness.

CONCLUSIONS

The use of nonporous polyethylene barrier sheet implant for orbital fracture repair is a safe and effective alternative to nonporous nylon foil implants. There were no complications and one case of residual diplopia (2.1%) in this case series.

Co-culture of adipose-derived stem cells and chondrocytes on three-dimensionally printed bioscaffolds for craniofacial cartilage engineering

OBJECTIVES/HYPOTHESIS

Reconstruction of craniofacial cartilagenous defects are among the most challenging surgical procedures in facial plastic surgery. Bioengineered craniofacial cartilage holds immense potential to surpass current reconstructive options, but limitations to clinical translation exist. We endeavored to determine the viability of utilizing adipose-derived stem cell-chondrocyte co-culture and three-dimensional (3D) printing to produce 3D bioscaffolds for cartilage tissue engineering. We describe a feasibility study revealing a novel approach for cartilage tissue engineering with in vitro and in vivo animal data.

METHODS

Porcine adipose-derived stem cells and chondrocytes were isolated and co-seeded at 1:1, 2:1, 5:1, 10:1, and 0:1 experimental ratios in a hyaluronic acid/collagen hydrogel in the pores of 3D-printed polycaprolactone scaffolds to form 3D bioscaffolds for cartilage tissue engineering. Bioscaffolds were cultured in vitro without growth factors for 4 weeks and then implanted into the subcutaneous tissue of athymic rats for an additional 4 weeks before sacrifice. Bioscaffolds were subjected to histologic, immunohistochemical, and biochemical analysis.

RESULTS

Successful production of cartilage was achieved using a co-culture model of adipose-derived stem cells and chondrocytes without the use of exogenous growth factors. Histology demonstrated cartilage growth for all experimental ratios at the post-in vivo time point confirmed with type II collagen immunohistochemistry. There was no difference in sulfated-glycosaminoglycan production between experimental groups.

CONCLUSION

Tissue-engineered cartilage was successfully produced on 3D-printed bioresorbable scaffolds using an adipose-derived stem cell and chondrocyte co-culture technique. This potentiates co-culture as a solution for several key barriers to a clinically translatable cartilage tissue engineering process.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E251-E257, 2018.

Scaffold-Assisted Artificial Hair Implantation in a Rat Model

IMPORTANCE

Current treatments for alopecia with autograft hair transplantation face limitations that may preclude complete hair restoration and leave patients with donor site scars. Scaffold assisted artificial hair implantation as demonstrated in a rat model may provide an adjunct for hair restoration without donor site morbidity.

OBJECTIVE

To design and create porous high-density polyethylene (PHDPE) and expanded polytetrafluoroethylene (ePTFE) hair-bearing scaffolds and evaluate their biocompatibility in a rat model.

DESIGN, SETTING, AND PARTICIPANTS

For this single-institution randomized prospective animal study, 34 Sprague Dawley rats were randomly selected into 2 groups: 24 rats for direct implantation and 10 rats for delayed implantation. The direct-implantation group was randomly divided into 3 subgroups of 8 rats, which were observed for 2, 12, and 24 week.

INTERVENTIONS

Each rat dorsum was implanted with 4 scaffolds-PHDPE and ePTFE with and without hair-in a randomized 4-quadrant manner. The rats in the direct-implantation group were observed to their selected time points of 2, 12, and 24 weeks. The rats in the delayed-implantation group were observed for 4 weeks at which, all well-healed scaffolds without hair were then percutaneously implanted with 2 follicular units of hair. These rats were then observed for another 4 weeks.

MAIN OUTCOMES AND MEASURES

During the clinical observation period, scaffolds were observed for signs of infection, extrusion, and persistence of follicular units. Following sacrifice, sagittal sections of scaffold and surrounding skin were fixed in formalin, stained with hematoxylin-eosin, and evaluated for degree of fibrovascular invasion and acute and chronic inflammation.

RESULTS

Overall 94.5% (86 of 91) of the scaffolds were well healed at time of evaluation (2 week, 100% [32 of 32]; 12 week, 96.3% [26 of 27]; 24 week, 87.5% [28 of 32]); while 85.6% of artificial hair follicular units were intact at time of evaluation (2 week, 93.8% [30 of 32]; 12 week, 86.7% [26 of 30]; 24 week, 75.0% [21 of 28]). Within the delayed implant group 100% (19 of 19) of the hair-implanted scaffolds were well healed at 8 weeks, with 94.7% (36 of 38) of the follicular units intact; 100% of the delayed-hair implant scaffolds were well healed with 86.1% (36 of 38) of the follicular units intact. Kaplan-Meier log-rank analysis showed no significant difference in survival between ePTFE and PHDPE scaffolds, as well as scaffolds with hair and scaffolds without hair. Upon histological analysis, overall scaffolds with hair were noted to have greater chronic inflammation (95% CI, -0.81 to -1.10; P = .01), and PHDPE was noted to have significantly great fibrovascular integration (95% CI, -11.42 to -1.96; P = .01) compared with ePTFE.

CONCLUSIONS AND RELEVANCE

Overall, PHDPE and ePTFE hair bearing scaffolds were well tolerated in a rat model. Progressive loss of artificial hair may be percutaneously implanted without significant increases in infection or extrusion.

LEVEL OF EVIDENCE

NA.

Burn Ear Reconstruction Using Porous Polyethylene Implants and Tissue Expansion

Reconstruction of the external ear after a burn is particularly challenging. The nature of the injury poses many problems including excessive scar tissue, poor blood supply, and the lack of adequate and appropriate materials for a framework. The use of costochondral grafts often leads to marginal outcomes which do not justify the morbidity. Children under the age of 10 years commonly have insufficient cartilage for a graft. Medpor (Stryker, Kalamazoo, MI) offers minimal morbidity and a very effective result. In this series, the authors describe the experience using Medpor and scalp tissue expansion to reconstruct severely burned ears. A total of 16 pediatric patients underwent 18 reconstructions, with two patients receiving bilateral procedures. All patients received Medpor implants. Thirteen patients were tissue expanded under the subgaleal plane before reconstruction, for concomitant scalp alopecia reconstruction. Eleven temporoparietal fascial flaps were performed. In the remaining patients, coverage of the implant was achieved by local advancement flaps. Only two patients had complications, with exposure of the construct after several years. In these two cases, the implants were removed. The experience has shown porous polyethylene reconstruction to be very efficient, with low morbidity and good cosmetic outcomes. Medpor is an excellent option for the reconstruction of both fully and partially burned ears as you may implant only the helical rim, base, or both pieces. The best results were achieved after tissue expansion and the use of the alopecic skin overlying a temporoparietal fascial flap. This has become the preferred method.

Recent advances in the reconstruction of cranio-maxillofacial defects using computer-aided design/computer-aided manufacturing

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

Computer-Assisted Planning and 3D Printing-Assisted Modeling for Chin Augmentation

BACKGROUND

Patients are frequently not satisfied with the outcome of chin augmentation.

OBJECTIVES

We report the use of three-dimensional (3D) imaging and printing to design custom fit porous polyethylene chin implants.

METHODS

Patients requesting chin augmentation received 3D computed tomography (CT) imaging of the facial area. Patients could select the chin contour they desired by viewing 3D images of their face and chin. A 3D mandible replicate was printed from the CT data, and used to sculpt the inner surface of the implant to match the shape of the mandible, and the outer surface to match the contour the patient desired. Implants were placed with a 2 cm mucosal incision. The primary outcome was patient satisfaction with the cosmetic result at 6 months postoperatively.

RESULTS

From April 2014 to March 2015, 107 females and 22 males (mean age, 29.7 years) received chin augmentation using 3D imaging and printing to create a custom fit porous polyethylene implant. No major complications (eg, infection, nerve injury) occurred. At 1 month, five of the 124 patients who returned for follow up were not satisfied; however, became satisfied after a minor adjustment procedure. All of the 78 patients that returned for the 6 month follow up were satisfied with the cosmetic result. No implant displacement, skin numbness, or infection was noted during the 6 months of follow up.

CONCLUSIONS

Three-dimensional imaging and printing can be used to produce custom fit porous polyethylene chin implants that results in minimal complications and a very high satisfaction rate.

LEVEL OF EVIDENCE

4.

Clinical Experience with the M4 Ahmed Glaucoma Drainage Implant

Aim

To evaluate the safety and efficacy of the M4 (porous polyethylene plate) Ahmed Glaucoma Valve (AGV) drainage implant in a multicenter retrospective study.

Materials and methods

A retrospective chart review of medical records of patients who had undergone the M4 Ahmed valve was performed from January 2013 to April 2015. The primary outcome measure was surgical failure defined as: Less than a 20% reduction in baseline intraocular pressure (IOP) to last follow-up visit, final IOP less than 5 mm Hg or greater than 18 mm Hg, reoperation for glaucoma, or loss of light perception vision. All eyes not meeting the above criteria were defined as success.

Results

A total of 291 eyes met all study inclusion criteria. The average follow-up in the study was 6 months (±7.6 months) with 112 patients achieving 12-month follow-up (38.5%). 208 eyes (71.5%) met the study success criteria at final follow-up. No statistically significant spikes in postoperative IOP at 1 and 4 months were detected. The average preoperative IOP was 26.0 on an average of 2.8 medications. At 6 months, the average IOP dropped to 16.7 on 0.9 medications and stayed relatively stable at 15.8 on 1.2 medications at 12-month follow-up.

Conclusion

The M4 valve appears to have less of a hypertensive phase compared with the other Ahmed class valves with a similar safety profile. While 71.5% success rate was achieved at final follow-up, the failure rate steadily increased over time.

Clinical significance

While the M4 production has been discontinued, the porous design of the M4 may avoid a pressure spike in the Ahmed valve class and warrants future investigation for valve design.How to cite this article: Sluch I, Gudgel B, Dvorak J, Ahluwalia MA, Ding K, Vold S, Sarkisian S. Clinical Experience with the M4 Ahmed Glaucoma Drainage Implant. J Curr Glaucoma Pract 2017;11(3):92-96.

A comparative multi-parametric in vitro model identifies the power of test conditions to predict the fibrotic tendency of a biomaterial

Despite growing effort to advance materials towards a low fibrotic progression, all implants elicit adverse tissue responses. Pre-clinical biomaterial assessment relies on animals testing, which can be complemented by in vitro tests to address the Russell and Burch’s 3R aspect of reducing animal burden. However, a poor correlation between in vitro and in vivo biomaterial assessments confirms a need for suitable in vitro biomaterial tests. The aim of the study was to identify a test setting, which is predictive and might be time- and cost-efficient. We demonstrated how sensitive in vitro biomaterial assessment based on human primary macrophages depends on test conditions. Moreover, possible clinical scenarios such as lipopolysaccharide contamination, contact to autologous blood plasma, and presence of IL-4 in an immune niche influence the outcome of a biomaterial ranking. Nevertheless, by using glass, titanium, polytetrafluorethylene, silicone, and polyethylene representing a specific material-induced fibrotic response and by comparison to literature data, we were able to identify a test condition that provides a high correlation to state-of-the-art in vivo studies. Most important, biomaterial ranking obtained under native plasma test conditions showed a high predictive accuracy compared to in vivo assessments, strengthening a biomimetic three-dimensional in vitro test platform.

Soft and Firm Alloplastic Implants in Rhinoplasty: Why, When and How to Use Them: A Review of 311 Cases

BACKGROUND

Modern rhinoplasty is not just a reduction procedure. An optimal nasal esthetic result occasionally requires augmenting the nasal tip, the dorsum or the lateral wall with autografts or alloplasts. A large number of nasal implant types have been reported in the medical literature.

OBJECTIVE

The goal of this article is to demystify the role and indications of nasal implants in rhinoplasty. As well, it offers both the novice and experienced nasal surgeon a basic, simplified and organized approach to the use of soft and firm nasal implants in rhinoplasty.

METHODS

This article presents the authors experience with 311 rhinoplasties using both soft and firm alloplastic implants. The indications for both types of alloplasts are discussed, the surgical technique detailed and the outcomes analyzed.

RESULTS

A total of 311 nasal implant cases were reviewed. This series revealed a low incidence of postoperative infection (5.57% for soft implants and 0.1% for the firm ones). The revision rate was 2.7% for the soft implants group and 7.1% for the firm implants group.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Porous Polyethylene Implant as Aesthetic Complement in Orthognathic Surgery

Porous polyethylene implants have been used as an alternative in the treatment of patients with zygomatic and paranasal projections deficiency. These implants promote a facial rejuvenating effect due to the attenuation of the nasal and chin prominences. The advantages of porous polyethylene include biocompatibility, dimensional stability, easy adaptation and fixation, low complication rate, and its availability in different sizes and shapes. A 27-year-old woman presenting vertical deficiency associated with midface hypoplasia was treated with orthognathic surgery. Clockwise rotation and genioplasty were performed. In order to improve facial aesthetics, porous polyethylene implants were placed in the paranasal area, optimizing the facial contour with the correction of the midface projection.

Applications of Medpor Porous Polyethylene in Facial Bone Augmentation

We report our experience in facial bone augmentation and nasal dorsal onlays with the Medpor porous polyethylene implant. Medpor is a highly stable, somewhat flexible alloplast which has been sintered to form a network of interconnecting pores. Its surface characteristics and porosity have been shown to promote rapid tissue ingrowth, vascularization, and fixation to the underlying bone. A total of 88 implants were placed in 68 patients during a 5-year period. Implants were used for augmentation in the chin (15), malar area (11), nasal dorsum (20), the orbit (19), and the cranium (23). The patients ranged in age from 10 to 76 years old. The etiologies of deformities were related to trauma (40), burns (17), aesthetic (8), and congenital (3). One malar implant became infected and was removed. There were no other implant-related complications. As a result of rapid soft-tissue ingrowth all implants became firmly fixed in position. No subsequent bone resorption, implant migration, or exposure were observed in our patient group. On the basis of these findings, we recommend the Medpor porous polyethylene implant as a dependable choice in the array of alloplastic materials available for facial reconstruction. Its remarkable stability, conductivity for tissue ingrowth, and ease of use allow for an accurate and reliable establishment of contour and symmetry in the craniofacial skeleton.

Long-term infectious complications of using porous polyethylene mesh for orbital fracture reconstruction

Porous polyethylene is a widely used implants in orbital reconstruction, on which comprehensive clinical analysis, various treatments, and different prognosis according to specific classification principles on long-term complications have not been reported.To investigate the new clinical symptoms, intraoperative findings, treatments, and outcomes of complications long period after previous surgery, resulting from the use of porous polyethylene mesh for orbital fracture reconstruction.A retrospective study was conducted on 21 patients at the Department of Ophthalmology, Shanghai Ninth People's Hospital with orbital complications after orbital fracture reconstruction with porous polyethylene mesh for 4 ± 2.2 years from 2011 to 2013. These data included new clinical symptoms after previous surgery, computerized tomography data, intraoperative findings, treatments, and outcomes.Data from 21 patients were analyzed in this study. Two patients received conservative treatment, while the other 19 patients underwent surgical approaches. Classification principles for orbital complications after orbital wall defect reconstruction with porous polyethylene mesh were formulated according to patients' new clinical symptoms, computed tomography (CT), and intraoperative findings after previous surgery. In the last follow-up, 19 patients (90.5%) were cured or improved according to our assessment principle. The follow-up ranged from 3 to 45 months (35 months in average).According to specific classification for orbital complications resulting from the use of porous polyethylene mesh for orbital fracture reconstruction, various medical treatments should be carried out, and the prognosis may be different.

"Ride-on" technique and other simple and logical solutions to counter most common complications of silicone implants in augmentation rhinoplasty

Augmentation rhinoplasty can be carried out using a wide range of materials including autologous bone and/or cartilage as well as alloplasts. Use of biologic bone and cartilage grafts results in lower infection rates, but they are associated with long-term resorption and donor-site morbidity. Alloplastic materials, in particular silicone, have been associated in literature with extrusion, necrosis of the tip, mobility and deviation or displacement of the implant, immobile nasal tip and infection. However, they have the advantages of being readily available and easy to reshape with no requirement for harvesting autografts.

Biochemical properties of tissue-engineered cartilage

OBJECTIVE

Microtia is treated with rib cartilage sculpting and staged procedures; though aesthetically pleasing, these constructs lack native ear flexibility. Tissue-engineered (TE) elastic cartilage may bridge this gap; however, TE cartilage implants lead to hypertrophic changes with calcification and loss of flexibility. Retaining flexibility in TE cartilage must focus on increased elastin, maintained collagen II, decreased collagen X, with prevention of calcification. This study compares biochemical properties of human cartilage to TE cartilage from umbilical cord mesenchymal stem cells (UCMSCs). Our goal is to establish a baseline for clinically useful TE cartilage.

METHODS

Discarded cartilage from conchal bowl, microtic ears, preauricular tags, rib, and TE cartilage were evaluated for collagen I, II, X, calcium, glycosaminoglycans, elastin, and fibrillin I and III. Human UCMSCs were chondroinduced on 2D surfaces and 3D D,L-lactide-co-glycolic acid (PLGA) fibers.

RESULTS

Cartilage samples demonstrated similar staining for collagens I, II, and X, elastin, and fibrillin I and III, but differed from rib. TE pellets and PLGA-supported cartilage were similar to auricular samples in elastin and fibrillin I staining. TE samples were exclusively stained for fibrillin III. Only microtic samples demonstrated calcium staining.

CONCLUSIONS

TE cartilage expressed similar levels of elastin, fibrillin I, and collagens I and X when compared to native cartilage. Microtic cartilage demonstrated elevated calcium, suggesting this abnormal tissue may not be a viable cell source for TE cartilage. TE cartilage appears to recapitulate the embryonic development of fibrillin III, which is not expressed in adult tissue, possibly providing a strategy to control TE elastic cartilage phenotype.