Optimizing Tissue Engineering for Clinical Relevance in Rotator Cuff Repair

Rotator cuff tear (RCT) is the most common cause of disability in the upper extremity. It results in 4.5 million physician visits in the United States every year and is the most common etiology of shoulder conditions evaluated by orthopedic surgeons. Over 460,000 RCT repair surgeries are performed in the United States annually. Rotator cuff (RC) retear and failure to heal remain significant postoperative complications. Literature suggests that the retear rates can range from 29.5% to as high as 94%. Weakened and irregular enthesis regeneration is a crucial factor in postsurgical failure. Although commercially available RC repair grafts have been introduced to augment RC enthesis repair, they have been associated with mixed clinical outcomes. These grafts lack appropriate biological cues such as stem cells and signaling molecules at the bone-tendon interface. In addition, they do little to prevent fibrovascular scar tissue formation, which causes the RC to be susceptible to retear. Advances in tissue engineering have demonstrated that mesenchymal stem cells (MSCs) and growth factors (GFs) enhance RC enthesis regeneration in animal models. These models show that delivering MSCs and GFs to the site of RCT enhances native enthesis repair and leads to greater mechanical strength. In addition, these models demonstrate that MSCs and GFs may be delivered through a variety of methods including direct injection, saturation of repair materials, and loaded microspheres. Grafts that incorporate MSCs and GFs enhance anti-inflammation, osteogenesis, angiogenesis, and chondrogenesis in the RC repair process. It is crucial that the techniques that have shown success in animal models are incorporated into the clinical setting. A gap currently exists between the promising biological factors that have been investigated in animal models and the RC repair grafts that can be used in the clinical setting. Future RC repair grafts must allow for stable implantation and fixation, be compatible with current arthroscopic techniques, and have the capability to deliver MSCs and/or GFs.

Assessing Bioprinted Functionalized Grafts for Biological Tendon Augmentation In Vitro

Tendinopathy, characterized by inflammatory and degenerative changes, presents challenges in sports and medicine. In addressing the limitations of conservative management, this study focuses on developing tendon grafts using extrusion bioprinting with platelet-rich plasma (PRP)-infused hydrogels loaded with tendon cells. The objective is to understand paracrine interactions initiated by bioprinted tendon grafts in either inflamed or non-inflamed host tissues. PRP was utilized to functionalize methacrylate gelatin (GelMA), incorporating tendon cells for graft bioprinting. Bioinformatic analyses of overexpressed proteins, predictive of functional enrichment, revealed insights into PRP graft behavior in both non-inflamed and inflamed environments. PRP grafts activated inflammatory pathways, including Interleukin 17 (IL-17), neuroinflammation, Interleukin 33 (IL-33), and chemokine signaling. Interleukin 1 beta (IL-1b) in the graft environment triggered p38 mitogen-activated protein kinase (MAPK) signaling, nuclear factor kappa light chain enhancer of activated B cells (NF-kB) canonical pathway, and Vascular Endothelial Growth Factor (VEGF) signaling. Biological enrichment attributed to PRP grafts included cell chemotaxis, collagen turnover, cell migration, and angiogenesis. Acellular PRP grafts differed from nude grafts in promoting vessel length, vessel area, and junction density. Angiogenesis in cellular grafts was enhanced with newly synthesized Interleukin 8 (IL-8) in cooperation with IL-1b. In conclusion, paracrine signaling from PRP grafts, mediated by chemokine activities, influences cell migration, inflammation, and angiogenic status in host tissues. Under inflammatory conditions, newly synthesized IL-8 regulates vascularization in collaboration with PRP.

Using RAFT Polymerization Methodologies to Create Branched and Nanogel-Type Copolymers

This review aims to highlight the most recent advances in the field of the synthesis of branched copolymers and nanogels using reversible addition-fragmentation chain transfer (RAFT) polymerization. RAFT polymerization is a reversible deactivation radical polymerization technique (RDRP) that has gained tremendous attention due to its versatility, compatibility with a plethora of functional monomers, and mild polymerization conditions. These parameters lead to final polymers with good control over the molar mass and narrow molar mass distributions. Branched polymers can be defined as the incorporation of secondary polymer chains to a primary backbone, resulting in a wide range of complex macromolecular architectures, like star-shaped, graft, and hyperbranched polymers and nanogels. These subcategories will be discussed in detail in this review in terms of synthesis routes and properties, mainly in solutions.

Immediate Results of the Use of Split-Thickness Skin Autografts With and Without Acellular Dermal Matrix in Patients with Burns: A Comparative Study in a Colombian Population

Dermal substitutes have become fundamental tools for covering skin defects, most recently with biological subtypes such as glycerolized acellular dermal matrix (GADM). However, literature regarding this matter is scarce in Latin America and Colombia. In this descriptive observational study, we compared the use of partial skin autografts (PSA) combined with GADM and autografts without GADM. Patients were selected from the burn unit of a hospital in northeastern Colombia between 2021 and 2022. Two study groups were defined: one receiving GADM plus PSA and the other control receiving only a partial split-thickness autograft. A total of 29 patients with 68 body areas were included, with an average age of 20 years. Most cases involved third-degree burns caused by flame. Hospitalization time was the same for both groups (41 days). The percentage of grafts taken was similar in both groups; in the GADM with autografts group, it was 94.7% compared with 96% in the control group. The presence of complications was similar in both groups. GADM produced in local tissue banks is a cost-effective alternative. It can be used in a single surgical procedure without increasing complications, providing a postsurgical course similar to autografts alone. Granting the potential long-term benefits that dermal matrices give for healing in these patients, which should be evaluated in subsequent studies.

Early Postoperative Complications in Microtia Reconstruction: An Analysis of the NSQIP-P Database

OBJECTIVES

Microtia and anotia repair require techniques that consider both aesthetics and function. The outcomes of different reconstructive frameworks such as costal cartilage or a porous polyethylene implant have not been evaluated on a national scale. We aim to understand differences in outcomes/complication rates and operative times between different reconstructive frameworks used in microtia/anotia reconstruction.

METHODS

This was a retrospective review of the National Surgical Quality Improvement Program Pediatric database between 2012-2019. Patients with ICD-9/10 codes for microtia/anotia were isolated. Reconstruction methods were identified using CPT codes for rib graft, ear cartilage graft, and alloplastic implants (biocompatible implants, porous polyethylene, etc). Outcomes included operative-time, wound complications, and unplanned re-operations within 30 days of surgery. Multivariable logistic regression was performed to control for confounders.

RESULTS

We included 593 patients for analysis. Reconstruction with rib grafts (N = 506, 85%) was the most common. In 58 patients (9.8%), an implant was used for the auricular framework, whereas in 47 (7.9%) ear cartilage grafts were used. The overall wound complication rate was 3.4%. On univariate analysis, alloplastic implants exhibited a higher rate of wound complications (8.6% vs. 2.8%, p = 0.037) and longer operative times (350 min vs. 235 min, p < 0.001). After controlling for demographics and comorbidities, implants conferred an independently increased risk of wound complications (OR 3.52, 1.10-9.54, p = 0.020).

CONCLUSION

Although the use of alloplastic implants (e.g., porous polyethylene) may confer an increased risk of early complications, the long-term clinical implications of these findings are unclear relative to aesthetic benefits. Multi-institutional studies are needed to validate these findings using patient-specific and surgeon-specific data.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1214-1219, 2024.

Comparison of perichondrium-cartilage button technique and traditional over-underlay technique for repairing large perforations

OBJECTIVE

This study was performed to compare the operation time, graft outcomes and complications between the endoscopic cartilage-perichondrium button technique and over-under technique for repairing large perforations.

METHODS

A total of 52 chronic large perforations were randomly allocated to receive treatment using the endoscopic cartilage-perichondrium button technique (n = 26) or over-under technique (n = 26). The graft outcomes, mean operation time and post-operative complications were compared between the two groups at 12 months.

RESULTS

The study population consisted of 52 patients with unilateral chronic large perforations. All patients completed 12 months of follow up. The mean operation time was 32.3 ± 4.2 minutes in the button technique group and 51.6 ± 2.8 minutes in the over-underlay technique group (p < 0.01). The graft success rate at 12 months was 92.3 per cent (24 out of 26) in the button technique group and 96.2 per cent (25 out of 26) in the over-underlay group (p = 0.552).

CONCLUSION

The endoscopic cartilage-perichondrium button technique had similar graft success rates and hearing outcomes for large chronic perforations to the over-under technique, but significantly shortened the mean operation time.

Critical-size defects reconstruction with four different bone grafts associated with e-PTFE membrane: A histomorphometric experimental in vivo study

OBJECTIVES

The goal of this study was to assess the newly formed bone and the remnant biomaterial by comparing four different bone grafts used to treat critical-size defects, associated or not with the non-resorbable membrane.

MATERIALS AND METHODS

Two calvaria critical-size bone defects were created in 50 male Wistar rats. They were divided into blood (G1), autogenous (G2), bioglass (G3), hydroxyapatite (G4), and xenograft (G5) groups, associated or not with e-PTFE. The experimental periods were 15 and 45 days. Sections were prepared for histomorphometric assessment. All data were analyzed by the mixed-effects model with multiple comparisons (significance level, p < .05).

RESULTS

A similar level of new bone was observed for all groups, associated with a high level of vascularization. G1 and G2 ensured sovereignty over the greater quantity of new bone. A non-significant result was reported comparing groups with and without membranes. No significant result was found between the experimental synthetic biomaterials (G3 and G4). G5L achieved 22.0% of new bone after 45 days (p > .05). All groups had a stable volume of biomaterial kept in the short term (p > .05). G2 was the best material for new bone formation and final volume of biomaterial, followed by G4 < G5 < G3. Thus, it is possible that G4 had a better degradation profile among the experimental groups.

CONCLUSIONS

The best results were found in the autogenous group, with higher resorption and integration; non-significative new bone was found among the experimental groups; and the regeneration of critical bone defects using an e-PTFE barrier did not present significant results on new bone formation.

The Effects of IL-23/IL-18-Polarized Neutrophils on Renal Ischemia-Reperfusion Injury and Allogeneic-Skin-Graft Rejection in Mice

Neutrophils display heterogeneity and plasticity with different subgroups and immune-regulatory functions under various surrounding conditions. Neutrophils induced by IL-23/IL-18 (referred to N(IL-23+IL-18) neutrophils) have a unique gene-expression profile, with highly expressing IL-17, MHC-II, and costimulatory molecules. The adoptive transfer of N(IL-23+IL-18) neutrophils significantly increased the pathogenesis in a renal ischemia-reperfusion injury mouse model. N(IL-23+IL-18) neutrophils directly and efficiently induced allogeneic T cell proliferation in vitro. N(IL-23+IL-18) neutrophils enhanced the syngeneic T cell response to allogeneic antigens in mixed-lymphocyte reaction assays. The adoptive transfer of the donor or host N(IL-23+IL-18) neutrophils significantly enhanced the antidonor antibody production in an allogeneic-skin-transplanted mouse model, accompanied by increased Tfh cells in the spleens. Therefore, the neutrophil subset induced by IL-23/IL-18 promotes tissue injury and antidonor humoral response in the allogeneic transplantation mouse model.

Exploring the Impact of Blend and Graft of Quinoline Derivative in Low-Temperature Curable Polyimides

The utilization of accelerators has been a common approach to prepare low-temperature curable polyimide (PI). However, the accelerators have gradually fallen out of favor because of their excessive dosages and negative effect on the properties of PI. In this work, a new strategy of introducing accelerators by grafting to eliminate these disadvantages is presented. A novel quinoline derivative named 6-([1,1'-biphenyl]-4-yl)-4-chloroquinoline (NQL) is designed for this purpose, and an ultralow dosage of only 2.5 mol% is sufficient to prepare low-temperature curable PI. The favorable low-temperature curing effect of NQL is attributed to its strong alkalinity (pKa = 18.47) and electron-donating ability. At a curing temperature of 200 °C, the PI with 2.5 mol% NQL showed outstanding properties (Young's modulus of 5.73 GPa, elongation of 37.3%, tensile strength of 237 MPa, and coefficient of thermal expansion of 16 ppm K-1 ). In particular, NQL can even lower the curing temperature to 180 °C and the ultralow temperature curable PI film still retains excellent properties. These results demonstrate that introducing low-temperature curable accelerators by partial grafting instead of blending is a promising way to furnish low-temperature curable PI, and provide insights into the preparation of polyimide with high performance in advanced packaging.

Deep palm burn treated with enzymatic debridement followed by autologous skin cell suspension: a case study

Despite improvements in treatment methods and outcomes, burns remain one of the principal causes of mortality and morbidity worldwide. Burns involving the hands are estimated to occur in >80% of people with burns. Hand burns have also been associated with long-term social, psychological and physical consequences that can impede a patient's full reintegration to the community and decrease their overall quality of life. Clinically, when the trajectory towards complete re-epithelialisation stalls in deep burn wounds of the hand, skin grafting is indicated, but cosmetic problems often remain. A recent publication highlighted common complications for burns involving the hand such as scar disturbances (26%) and scar contractures (14%). Innovative approaches with the potential to reduce the occurrence of complicating scar disturbances and contractures are sought by healthcare providers specialising in burns. This case report describes a novel approach to wound closure using a topical concentrate of proteolytic enzymes followed by the application of an autologous skin cell suspension. This combination was effective in achieving early and complete re-epithelialisation of a deep burn of the palm of a 28-year-old male patient, while potentially affording a favourable impact on hypertrophic scarring or scar contracture.

Bone Marrow Stem Cells with Tissue-Engineered Scaffolds for Large Bone Segmental Defects: A Systematic Review

Critical-sized bone defects (CSBDs) represent a significant clinical challenge, stimulating researchers to seek new methods for successful bone reconstruction. The aim of this systematic review is to assess whether bone marrow stem cells (BMSCs) combined with tissue-engineered scaffolds have demonstrated improved bone regeneration in the treatment of CSBD in large preclinical animal models. A search of electronic databases (PubMed, Embase, Web of Science, and Cochrane Library) focused on in vivo large animal studies identified 10 articles according to the following inclusion criteria: (1) in vivo large animal models with segmental bone defects; (2) treatment with tissue-engineered scaffolds combined with BMSCs; (3) the presence of a control group; and (4) a minimum of a histological analysis outcome. Animal research: reporting of in Vivo Experiments guidelines were used for quality assessment, and Systematic Review Center for Laboratory animal Experimentation's risk of bias tool was used to define internal validity. The results demonstrated that tissue-engineered scaffolds, either from autografts or allografts, when combined with BMSCs provide improved bone mineralization and bone formation, including a critical role in the remodeling phase of bone healing. BMSC-seeded scaffolds showed improved biomechanical properties and microarchitecture properties of the regenerated bone when compared with untreated and scaffold-alone groups. This review highlights the efficacy of tissue engineering strategies for the repair of extensive bone defects in preclinical large-animal models. In particular, the use of mesenchymal stem cells, combined with bioscaffolds, seems to be a successful method in comparison to cell-free scaffolds.

Reconstruction of the anterior cruciate ligament: a historical view

Management of anterior cruciate ligament (ACL) tears has continuously evolved since its first description in approximately 170 A.D. by Claudius Galenus of Pergamum and Rome. The initial immobilization using casts was replaced by a variety of surgical and conservative approaches over the past centuries. The first successful case of ACL repair was conducted by Mayo Robson in 1885, suturing cruciate at the femoral site. In the nineteenth century, surgical techniques were focused on restoring knee kinematics and published the first ACL repair. The use of grafts for ACL reconstruction was introduced in 1917 but gained popularity in the late 1900s. The introduction of arthroscopy in the 1980s represented the greatest milestones in the development of ACL surgery, along with the refinements of indications, development of modern strategies, and improvement in rehabilitation methods. Despite the rapid development and multitude of new treatment approaches for ACL injuries in the last 20 years, autografting has remained the treatment of choice. Compared to the initial methods, arthroscopic procedures are mainly performed, and more resistant and safer fixation devices are available. This results in significantly less trauma from the surgery and more satisfactory long-term results. The most commonly used procedures are still patellar tendon or hamstring autograft. Additionally, popular, but less common, is the use of quadriceps tendon (QT) grafts and allografts. In parallel with surgical developments, biological reconstruction focusing on the preservation of ACL remnants through the use of cell culture techniques, partial reconstruction, tissue engineering, and gene therapy has gained popularity. In 2013, Claes reported the discovery of a new ligament [anterolateral ligament (ALL)] in the knee that could completely change the treatment of knee injuries. The intent of these modifications is to significantly improve the primary restriction of rotational laxity of the knee after ACL injury. Kinematic studies have demonstrated that anatomic ACL reconstruction and anterolateral reconstruction are synergistic in controlling pivot displacement. Recently, there has been an increased focus on the application of artificial intelligence and machine learning to improve predictive capability within numerous sectors of medicine, including orthopedic surgery.

Anatomy of the anterior cruciate ligament and the common autograft specimens for anterior cruciate ligament reconstruction

A thorough understanding of the anatomical properties of the native anterior cruciate ligament (ACL), as well as the native specimens that are most commonly considered as viable autograft choices for anterior cruciate ligament reconstruction (ACLR), is warranted for continuing to pursue the best-possible graft choice for patients undergoing ACLR. While a wide variety of graft choices remain available to the operating surgeon, choosing the correct graft choice remains a consideration and discussion with patients on the pros and cons of each option. This article combines a review of the current literature on the quantitative and qualitative anatomy of the native ACL and common autograft specimens with the expert consensus of the senior author on the surgically-pertinent anatomy of these structures. The purpose of this article is to review the anatomy pertaining to the native ACL, along with the distal anatomy of the hamstring tendons, patellar tendon and quadriceps tendon (QT). Multiple tendinous and ligamentous structures exist around the knee that serve as viable candidates for use as autologous grafts for ACLR, and the anatomy of these distal extents of these structures are discussed thoroughly, including bony attachments, quantitative and relational anatomy, cross sectional area, and histological features of these structures.

Physicochemical Characterization of Novel Biomaterial Consisting of Biphasic Calcium Phosphate, Chitosan, Casein and Ethanolic Leaves Extract of Ormocarpum Cochinchinense

Background

Bioceramics are widely used as a biomaterial to promote bone regeneration. Bone defect management requires the placement of bone grafts. Though there are many bone grafts available, these have certain limitations like limited supply and second surgical site morbidity. Phytochemicals in plants are known to have bone regeneration capacity and are used in traditional medicine for bone fracture healing.

Objective

The purpose of the study was to create a novel biomaterial consisting of a composite of biphasic calcium phosphate (BCP), chitosan (CH), casein (CA), and ethanolic leaves extract of Ormocarpum Cochinchinense (OC) fabricated and characterized for physicochemical properties.

Materials and Methods

BCP-CH-CA-OC material was prepared and immersed in Simulated body fluid (SBF) for 21 days. Physical properties were analysed through X-Ray diffraction (XRD), Fourier Transform Spectroscopy (FTIR), and Scanning Electron Microscopy with Energy dispersion spectroscopy (SEM/EDS). Mechanical properties were analysed by compressive strength and diametral tensile strength tests. Using BET (Brunauer-Emmett-Teller) analysis and Nano computed tomography (CT) scan, porosity measurements were made.

Results

XRD did not show any significant change after immersion in SBF, indicating that the material was not under change and is stable. FTIR showed an increase in chitosan content, due to the loss of casein. SEM analysis showed the deposition of crystals and porous structure. EDS showed the deposition of minerals. Nano CT and BET analysis showed clinically significant porosity of 30%.

Conclusion

The mechanical and physical properties of this novel biomaterial could be used in tissue engineering for the repair of bone defects in non-load-bearing areas. The physicochemical properties are at par with other materials used for the purpose of bone grafting. The novel biomaterial has the potential to be used in bone regenerative medicine in non-load-bearing applications.

Aneurysmal degeneration in the Omniflow II biosynthetic vascular graft

Despite advances in endovascular treatments, femoropopliteal bypass is still the best option for the treatment of lower-extremity occlusive artery disease. Omniflow II biosynthetic vascular grafts are often chosen as bypass grafts when autologous vein grafting is not possible. A negative feature of this graft is the tendency towards late biodegeneration with possible formation of graft aneurysms. In this case report, we present a thrombosed non-anastomotic biosynthetic graft aneurysm, which caused only a pulsatile mass in the inguinal region, in a 62-year-old male patient who had undergone a femoropopliteal bypass operation three years earlier. Aneurysm formation in vascular grafts is multifactorial and can cause life-threatening consequences. Therefore, all patients with biosynthetic vascular grafts should remain under lifetime surveillance with duplex ultrasound for aneurysmal graft degeneration and graft thrombosis.

Sandwich Technique for Large Osteochondral Lesions of the Knee

OBJECTIVE

To evaluate whether a sandwich technique procedure for large osteochondral lesions (OCL) of the medial femur condyle reduces clinical symptoms and improves activity level as well as to assess repair tissue integration on MRI over 2 years.

DESIGN

Twenty-one patients (median age: 29 years, 18-44 years) who received matrix-associated autologous chondrocyte transplantation (MACT) combined with cancellous bone grafting at the medial femur condyle in a 1-step procedure were prospectively included. Patients were evaluated before surgery (baseline) as well as 3, 6, 12, and 24 months postoperatively, including clinical evaluation, Lysholm score, Tegner Activity Rating Scale, and MRI with Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score and a modified Whole-Organ Magnetic Resonance Imaging Score (WORMS).

RESULTS

Seventeen patients were available for the 24-month (final) follow-up (4 dropouts). Lysholm significantly improved from 48 preoperatively stepwise to 95 at final follow-up (P < 0.05). Tegner improvement from 2.5 at baseline to 4.0 at final follow-up was not significant (P = 1.0). MOCART score improved significantly and stepwise from 65 at 3 months to 90 at 24 months (P < 0.05). Total WORMS improved from 14.5 at surgery to 7.0 after 24 months (P < 0.05). Body mass index and defect size at surgery correlated with total WORMS at final follow-up (P < 0.05) but did not correlate with clinical scores or defect filling.

CONCLUSION

MACT combined with cancellous bone grafting at the medial femoral condyle reduces symptoms continuously over 2 years. A 1-step procedure may reduce perioperative morbidity. However, despite improvements, patients' activity levels remain low, even 2 years after surgery.

Histologic characterization of orbicularis oris muscle with a new acellular dermal matrix grafts in a rabbit model

Muscular dysplasia is the key factor in influencing surgical outcomes in patients with cleft lip/palate. In this research, we attempted to evaluate a new acellular dermal matrix (ADM) as a substitute for reconstruction of the orbicularis oris muscle with growth factors such as Insulin-Like Growth Factor I (IGF-I), vascular endothelial growth factor (VEGF) in a rabbit model. 30 male New Zealand Rabbits (2-3 m, 1700-2000 g) were divided into four groups as follows; a group in which the orbicularis oris muscle of the upper lip was implanted with ADM, a group in which the orbicularis oris muscle of the upper lip was implanted with ADM + IGF-I + VEGF, a group in which the upper lip was operated without implantation of an ADM scaffold, and a normal upper lip for comparison. Macroscopic observation, histological evaluation, and immunohistochemistry were employed to evaluate levels of the muscle regeneration, vascularization, and inflammation at 1, 2, 4, 6, and 12 weeks after the operation. All wounds healed well without infection, immune rejection and so on. Histological evaluation showed that ADM was totally degraded and replaced by connective tissue. The area in which the ADM scaffold was coated with growth factors show a significant increase in the formation of new myofibers after injury, and the vascularization improved compared to the control group and the normal group. In regard to the degrees of inflammation, there were no notable differences among the groups. In conclusion, Our study indicated that ADM grafts combined with IGF-I and VEGF have potential advantages in alleviating muscular dysplasia in cleft lip treatment.

Buccal Mucosal Grafts as a Novel Treatment for the Repair of Rectovaginal Fistulas: Protocol for an Upcoming Prospective Single-Surgeon Case Series

Background

Rectovaginal fistulas (RVFs) are abnormal communications between the rectum/anus and the vagina. They are most frequently formed a result of obstetric injury and have deleterious effects on patients’ quality of life. Despite several treatment modalities, RVFs remain difficult problems to manage, and many patients fail multiple attempts at surgical repair. Buccal mucosal grafts (BMGs) may be a solution to this problem. A BMG is an oral mucosal tissue harvested from the inner cheek. There are 2 case reports that describe the successful use of BMGs in the repair of RVFs.

Objective

Our objective is to validate these findings with a prospective case series while also addressing the key issues of indication, technical details, procedure safety, and short-term outcomes.

Methods

A prospective single-surgeon case series will be undertaken at a university-affiliated academic tertiary care hospital in Calgary, Alberta (Canada). The estimated recruitment is between 3 and 5 patients. Patients will undergo surgical repair of their RVFs with an autologous BMG. Data on patient characteristics, fistula characteristics, and surgical variables will be collected and analyzed prospectively. The primary outcome is fistula closure. This study has been approved by the Conjoint Health Research Ethics Board at the University of Calgary (REB20-1123).

Results

Two previous case reports have described the successful use of BMGs in the repair of RVFs. We have received ethics approval to attempt to validate these findings through a prospective case series.

Conclusions

RVFs cause significant patient morbidity and are difficult problems to manage. Bolstered by the successful use of BMGs in urologic surgery and the previously published case reports demonstrating success in RVFs, we believe that BMGs may be a solution to RVFs.

International Registered Report Identifier (IRRID)

PRR1-10.2196/31003

Biomechanical Effects of Graft Shape for the Evans Lateral Column Lengthening Procedure: A Patient-Specific Finite Element Investigation

BACKGROUND

The Evans calcaneal lengthening osteotomy procedure is widely used for correcting progressive collapsing foot deformity. However, it can result in overcorrection and degenerations of the calcaneocuboid joint. Different shapes of graft have been used in the Evans calcaneal osteotomy, but potential differences in their biomechanical effects is still unclear. The present study was designed to explore the biomechanical effects of graft shape and improve the Evans procedure to avoid or minimize detrimental effects.

METHODS

Twelve patient-specific finite element models were established and validated. A triangular or rectangular wedge of varying size was inserted at the lateral edge of calcaneus, and the degree of correction was quantified. The stress in spring ligaments and plantar fascia and the contact characteristics of the talonavicular and calcaneocuboid joints were calculated and compared accordingly.

RESULTS

The rectangular graft provided a much higher degree of correction than triangular grafts did. However, the contact characteristics of the calcaneocuboid joint and talonavicular joint were abnormal, with clear sensitivity to increased graft size, and the modeled strain of the spring ligament increased.

CONCLUSION

The finite element analysis predicts that the rectangular grafts provide a higher degree of correction, but risks overcorrection compared with triangular grafts. The triangular graft may have a lower degree of disturbance to the biomechanical behaviors of the midtarsal joint.

CLINICAL RELEVANCE

The model shows that both the shape and size of an Evans osteotomy bone wedge can have effects on the contiguous joints and ligamentous structures. Those effects should be considered when selecting a bone wedge for an Evans calcaneal osteotomy.

LEVEL OF EVIDENCE

Level III, case-control study.

Brushite bone cement containing polyethylene glycol for bone regeneration

BACKGROUND

Bone cements aid in bone regeneration; however, if the handling time is not well established for the material to harden, complications may arise.

OBJECTIVE

This work investigates the effect of using polyethylene glycol (PEG) and characterize it in brushite bone cement in order to obtain desirable handling times as well as its regeneration in vivo to analyse if addition of this polymer may significantly modify its properties.

METHODS

PEG 4000 was synthesised with wollastonite by phosphorization reaction in order to form brushite which was further cured by oven drying. They were further characterised and tested in vivo as tibial bone defect model using rabbits.

RESULTS

Addition of PEG exhibited handling times of 60 min with a low increase in temperature when curing. Brushite phase of ∼71% was obtained after cement hardening with good compressive strength (25 MPa) and decent values of porosity (33%). In vivo presented that, at 40 days postoperatively, accelerated bone neoformation with partial consolidation at 30 days and total after 60 days when using bone cement.

CONCLUSIONS

Addition of PEG does not disrupt the beneficial properties of the bone cement and can be a potential alternative for control the time-temperature profile of hardening these materials.

Long-Term Survivorship and Clinical Outcomes of Osteochondral Autologous Transplantation for Steroid-Induced Osteonecrosis of the Knee

OBJECTIVE

Treatments for steroid-induced osteonecrosis of the knee remains challenging, and there has not been sufficient evidence to support joint preservation surgery. This study evaluated long-term outcomes of osteochondral autologous transplantation (OAT) for steroid-induced osteonecrosis of the knee.

DESIGN

This retrospective case series included patients who underwent OAT for steroid-induced osteonecrosis of the knee from 1998 to 2008. The survivorship and need for secondary surgery were evaluated, and the clinical outcome was evaluated with the International Knee Documentation Committee (IKDC) subjective score. Preoperative and final Kellgren-Lawrence (KL) grade of the femorotibial and patellofemoral joints were individually evaluated.

RESULTS

Fourteen knees of 10 patients whose mean age was 32.5 (95%CI 26.4-38.6) years were included and followed for 14.0 (12.4-15.7) years. The mean lesion size of 6.9 (5.3-8.5) cm² was repaired using 4 median (minimum 2, maximum 5) osteochondral plugs. No revision surgeries were performed for transplanted osteochondral plugs. The IKDC subjective score improved from 32.9 (24.5-41.3) to 74.2 (61.9-88.5) (P < 0.001). Knee flexion was improved at the final follow-up, and Seiza sitting was finally possible in 9 knees in 7 patients. Although the osteoarthritic change did not progress in femorotibial joint, patellofemoral joint showed early osteoarthritic changes at the final follow-up (mean KL grade: 0.8 [0.5-1.1]).

CONCLUSIONS

Prosthetic joint replacement was successfully avoided for at least the first decade by OAT in young patients with steroid-induced osteonecrosis of the knee. The progression of KL grade of the patellofemoral joint is of concern.

Osteochondral Repair and Electromechanical Evaluation of Custom 3D Scaffold Microstructured by Direct Laser Writing Lithography

OBJECTIVE

The objective of this study was to assess a novel 3D microstructured scaffold seeded with allogeneic chondrocytes (cells) in a rabbit osteochondral defect model.

DESIGN

Direct laser writing lithography in pre-polymers was employed to fabricate custom silicon-zirconium containing hybrid organic-inorganic (HOI) polymer SZ2080 scaffolds of a predefined morphology. Hexagon-pored HOI scaffolds were seeded with chondrocytes (cells), and tissue-engineered cartilage biocompatibility, potency, efficacy, and shelf-life in vitro was assessed by morphological, ELISA (enzyme-linked immunosorbent assay) and PCR (polymerase chain reaction) analysis. Osteochondral defect was created in the weight-bearing area of medial femoral condyle for in vivo study. Polymerized fibrin was added to every defect of 5 experimental groups. Cartilage repair was analyzed after 6 months using macroscopical (Oswestry Arthroscopy Score [OAS]), histological, and electromechanical quantitative potential (QP) scores. Collagen scaffold (CS) was used as a positive comparator for in vitro and in vivo studies.

RESULTS

Type II collagen gene upregulation and protein secretion was maintained up to 8 days in seeded HOI. In vivo analysis revealed improvement in all scaffold treatment groups. For the first time, electromechanical properties of a cellular-based scaffold were analyzed in a preclinical study. Cell addition did not enhance OAS but improved histological and QP scores in HOI groups.

CONCLUSIONS

HOI material is biocompatible for up to 8 days in vitro and is supportive of cartilage formation at 6 months in vivo. Electromechanical measurement offers a reliable quality assessment of repaired cartilage.

Health-Related Quality of Life in Ankle Osteoarthritis: A Case-Control Study

OBJECTIVE

Ankle osteoarthritis (OA) has a prevalence of 3.4% in the general population of which 70% to 78% is posttraumatic, affecting younger patients with a longer projected life span compared with hip and knee OA. The current literature reports the physical and mental quality of life (QoL) of patients with ankle OA, to be similar to end-stage hip OA, end-stage kidney disease and digestive heart failure. However, the QoL of ankle OA patients has not yet been determined compared with a matched control group representing the general population. Our aim is to determine the physical and mental QoL compared with a matched control group.

DESIGN

The Physical and Mental Component Summaries of the Short Form-36 of 100 patients with ankle OA were compared with 91 age- and gender-matched controls. This case-control study is a substudy of the PRIMA trial, in which the efficacy of platelet-rich plasma injections for ankle OA is determined.

RESULTS

A clinically relevant difference was found for both the Physical (P=0.003; 95% CI -6.7 to -1.3) and Mental Component Summary scores (P < 0.001; 95% CI -10 to -6). Patients with ankle OA had a median of 45 points (matched controls 52 points) and 43 points (matched controls 53 points) for the Physical and Mental Component summary scores, respectively.

CONCLUSIONS

Patients with ankle OA had a clinically relevant poorer mental and physical QoL compared with matched controls from the general population. Furthermore, the physical QoL of patients with ankle OA from younger age categories was affected more than those in older age categories.

SF-36 Physical Component Score Is Predictive of Achieving a Clinically Meaningful Improvement after Osteochondral Allograft Transplantation of the Femur

BACKGROUND

Osteochondral allograft (OCA) transplantation is an increasingly common treatment for patients with symptomatic focal chondral lesions of the knee. There has been increasing interest in determining predictive factors to maximize patient benefit after this operation. The aim of the present study is to evaluate the predictive association of the physical component (PCS) and mental component (MCS) scores of the Short Form 36 (SF-36) questionnaire for achievement of the minimal clinically important difference (MCID) after OCA transplantation.

METHODS

This retrospective study of a longitudinally maintained institutional registry included 91 patients who had undergone OCA transplantation for symptomatic focal osteochondral lesions of the femoral condyle. Included patients were those with complete preoperative questionnaires for the SF-36 and IKDC and completed postoperative IKDC at 2-year follow-up. Multivariate analysis was performed evaluating predictive association of the preoperative MCS and PCS with achievement of the MCID for the IKDC questionnaire.

RESULTS

Logistic multivariate modeling demonstrated a statistically significant association between lower preoperative PCS and achievement of the MCID (P = 0.022). A defect diameter >2 cm was also associated with achievement of MCID (P = 0.049). Preoperative MCS did not demonstrate a significant association (P = 0.09) with achievement of the MCID.

CONCLUSIONS

For this cohort of 91 patients, the preoperative SF-36 PCS and lesion size were predictive of achievement of the MCID at 2-year follow-up after femoral OCA transplantation. These findings support an important role of baseline physical health scores for predicting which patients will obtain a meaningful clinical benefit from this surgery.

Comparison of Clinical Outcome following Cartilage Repair for Patients with Underlying Varus Deformity with or without Additional High Tibial Osteotomy: A Propensity Score-Matched Study Based on the German Cartilage Registry (KnorpelRegister DGOU)

BACKGROUND

Even though realignment procedures have gained popularity as concomitant techniques in cartilage repair approaches with underlying malalignment, the clinical efficacy has not been proven to full extent.

METHODS

Out of 5474 patients from the German Cartilage Registry, 788 patients with focal cartilage defects on the medial femoral condyle having received either no accompanying surgery or high tibial osteotomy (HTO) were identified. After a 1:1 propensity score matching, outcome of 440 patients was evaluated using KOOS (Knee Injury and Osteoarthritis Outcome Score), VAS (visual analogue scale), and satisfaction during the 3-year follow-up.

RESULTS

Patients having received a concomitant HTO had significantly higher postoperative KOOS values (12 months: 67.26 ± 15.69 vs.75.10 ± 16.12, P = 0.001; 24 months: 67.14 ± 23.85 vs. 77.11 ± 16.50, P = 0.010; 36 months: 74.40 ± 16.57 vs. 81.75 ± 14.22, P = 0.023) and lower pain levels (6 months: 3.43 ± 2.18 vs. 2.89 ± 2.15, P = 0.009; 12 months: 3.64 ± 2.20 vs. 2.17 ± 1.96, P < 0.001; 24 months: 4.20 ± 3.12 vs. 2.94 ± 2.45, P = 0.005; 36 months: 3.20 ± 2.18 vs. 2.02 ± 1.98, P = 0.003). One and 3 years postoperatively, concomitant HTO led to significantly higher satisfaction in patients. These advantages of accompanying HTO were also seen in the group of patients with a varus deformity of 5° or more, in which pain levels without concomitant HTO even increased during the 3-year follow-up.

CONCLUSION

The results of the present study underline the importance and safety of concomitant HTO in patients with cartilage defects and varus deformity. HTO should therefore be considered and recommended generously in patients with focal cartilage defects of the medial femoral condyle and varus deformity.

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

The aim of the present systematic review was to investigate the effect of residual bone height (RBH) and vertical bone gain on new bone formation (NBF) and graft shrinkage after lateral sinus lifts using different biomaterials.

METHODS

An electronic search was conducted on three databases to identify randomized controlled trials (RCTs) published until January 2021 with at least one follow-up at 6 months and at least five patients treated, comparing biomaterials used for maxillary sinus augmentation with a lateral approach. Graft volumetric changes, RBH, vertical bone gain, implant failure, and post-operative complications were evaluated. The risk of bias was assessed using the Cochrane tool.

RESULTS

We used 4010 identified studies, of which 21 were RCTs. Overall, 412 patients and 533 sinuses were evaluated. Only three publications had an overall low risk of bias. After 6 months, xenograft (XG) showed the least volume reduction (7.30 ± 15.49%), while autogenous graft (AU) was the most reabsorbed (41.71 ± 12.63%). NBF appeared to not be directly correlated with RBH; on the contrary, the overall linear regression analysis showed that NBF significantly decreased by 1.6% for each mm of postoperative vertical graft gain. This finding suggests that the greater the augmentation, the lower the NBF. A similar tendency, with a regression coefficient even higher than the overall one, was also observed with alloplast (AP) and XG.

CONCLUSIONS

The present results suggested that NBF was essentially independent of preoperative bone height. On the contrary, the smaller the volume was of the graft placed, the higher the amount of new bone formed, and the smaller the graft shrinkage was. Minimizing the augmentation volume might be beneficial to graft healing and stability especially when using AP and XG.

Superdrainage Using the Cephalic Vein Due to Unsuitable Internal Thoracic Vein for Microvascular Anastomosis in Esophageal Reconstruction Using Pedicled Jejunum

The progress and popularization of microvascular surgical techniques may improve the outcomes of esophageal reconstruction using non-gastric tube (GT) grafts. A pedicled jejunum (PJ) with microvascular anastomoses is frequently selected as a reconstructed conduit for esophageal reconstruction when the GT is unavailable, and the internal thoracic (IT) vein is frequently selected as a recipient blood vessel for microvascular anastomosis. However, the IT vein may be inadequate for microvascular anastomosis because of its absence or underdevelopment. Since it is difficult to preoperatively predict such rare cases, it becomes necessary to urgently and rapidly prepare an alternative blood vessel. Herein, we present surgical procedures for superdrainage using the cephalic vein (CeV). Due the superficial nature of the CeV, it is both easy to identify and collect sufficient length. Thus, the CeV is very useful as an urgent substitute blood vessel when the IT vein is unavailable for microvascular anastomosis in esophageal reconstruction.

Osteochondritis Dissecans of Smaller Joints: The Elbow

This review presents the current understanding of the etiology, pathogenesis, and how to diagnose and treat osteochondritis dissecans (OCD) at the elbow joint followed by an analysis of particular characteristics and outcomes of the treatment. OCD is seen in patients with open growth plates (juvenile OCD [JOCD] and in adults [AOCD] with closed growth plates [adult OCD). The etiology at smaller joints remains as unclear as for the knee. Mechanical factors (throwing activities [capitulum] seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important for the diagnosis. In low-grade and stable lesions, treatment involves rest and different degrees of immobilization until healing. When surgery is necessary, the procedure depends on the OCD stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable while with damaged cartilage, several techniques are used. Techniques such as drilling and microfracturing produce a reparative cartilage while other techniques reconstruct the defect with osteochondral grafts or cell-based procedures such as chondrocyte implantation. There is a tendency toward better results when reconstructive procedures for both the bone and cartilage are used. In addition, comorbidities at the joint have to be treated. Severe grades of osteoarthritis are rare.

Reconstruction of the Swine Pulmonary Artery Using a Graft Engineered With Syngeneic Cardiac Pericytes

The neonatal heart represents an attractive source of regenerative cells. Here, we report the results of a randomized, controlled, investigator-blinded preclinical study, which assessed the safety and effectiveness of a matrix graft cellularized with cardiac pericytes (CPs) in a piglet model of pulmonary artery (PA) reconstruction. Within each of five trios formed by 4-week-old female littermate piglets, one element (the donor) was sacrificed to provide a source of CPs, while the other two elements (the graft recipients) were allowed to reach the age of 10 weeks. During this time interval, culture-expanded donor CPs were seeded onto swine small intestinal submucosa (SIS) grafts, which were then shaped into conduits and conditioned in a flow bioreactor. Control unseeded SIS conduits were subjected to the same procedure. Then, recipient piglets were randomized to surgical reconstruction of the left PA (LPA) with unseeded or CP-seeded SIS conduits. Doppler echocardiography and cardiac magnetic resonance imaging (CMRI) were performed at baseline and 4-months post-implantation. Vascular explants were examined using histology and immunohistochemistry. All animals completed the scheduled follow-up. No group difference was observed in baseline imaging data. The final Doppler assessment showed that the LPA’s blood flow velocity was similar in the treatment groups. CMRI revealed a mismatch in the average growth of the grafted LPA and contralateral branch in both treatment groups. Histology of explanted arteries demonstrated that the CP-seeded grafts had a thicker luminal cell layer, more intraparietal arterioles, and a higher expression of endothelial nitric oxide synthase (eNOS) compared with unseeded grafts. Moreover, the LPA stump adjacent to the seeded graft contained more elastin and less collagen than the unseeded control. Syngeneic CP engineering did not accomplish the primary goal of supporting the graft’s growth but was able to improve secondary outcomes, such as the luminal cellularization and intraparietal vascularization of the graft, and elastic remodeling of the recipient artery. The beneficial properties of neonatal CPs may be considered in future bioengineering applications aiming to reproduce the cellular composition of native arteries.

Ultrasonographic evaluation of the titanium-prepared platelet-rich fibrin effect in free gingival graft procedures

BACKGROUND

Complications after free gingival graft (FGG) operations are generally related to the donor site. The titanium-prepared, platelet-rich fibrin (T-PRF) placement in the donor site accelerate the wound healing and prevent postoperative complications such as pain and hemorrhage. We aim to evaluate the effect of T-PRF regarding vascularization and tissue thickness and to report the advantages of the ultrasonography (US) in FGG.

METHODS

Ten individuals were divided into two groups as T-PRF and control. While the T-PRF membrane was placed at the donor site in the T-PRF group, a gelatin sponge was placed in the control group. All patients underwent US examination in terms of vascularization and tissue thickness of left and right donor sites. The correlation between the right and left donor sites was analyzed with the Pearson correlation test. Tissue thicknesses and pulsatility index (PI) were analyzed with independent samples t-test. The results were evaluated statistically at the P <0.05 significance level.

RESULTS

The T-PRF group showed increased vascularity which can be interpreted to improve healing in soft tissue. However, not a difference, but a positively very high correlation was observed between the right and left tissue thicknesses (P = 0,00; r = +0902).

CONCLUSIONS

Evaluation of tissue thickness and vascularization density of donor sites with US not only increases clinical success rate but also reduces the risk of complications during surgery and postoperative pain in FGG. Studies evaluating T-PRF membrane as palatal dressing after FGG are only clinical, however, the efficiency of T-PRF was evaluated radiologically in this study for the first time.

Postmortem Studies of Fetal Grafts in Parkinson's Disease: What Lessons Have We Learned?

Neural transplantation is a potential therapeutic method for Parkinson’s disease (PD). Fetal dopaminergic (DA) neurons have been important transplantation cell sources in the history of replacement therapy for PD. Several decades of preclinical animal experiments and clinical trials using fetal DA neuron transplantation in PD therapy have shown not only promising results but also problems. In order to reveal possible factors influencing the clinical outcomes, we reviewed fetal DA neuron transplantation therapies from 1970s to present, with a special focus on postmortem studies. Firstly, we gave a general description of the clinical outcomes and neuroanatomy of grafted cases; secondly, we summarized the main available postmortem studies, including the cell survival, reinnervation, and pathology development. In the end, we further discussed the link between function and structure of the grafts, seeking for the possible factors contributing to a functional graft. With our review, we hope to provide references for future transplantation trials from a histological point of view.

Preclinical study analysis of massive magnesium alloy graft for calcaneal fractures

The highly comminuted calcaneal fractures represent a challenge for surgeons and require bone grafts for a good clinical outcome. Postoperative results are generally associated with increased morbidity and long periods of inactivity. The biomedical community promotes the use of artificial materials for grafts in order to achieve improved results. In an era when cosmetic concerns as well as the satisfaction of patients are mandatory and the use of autologous bone grafts is not without complications, an artificial replacement appears to be a favorable option. Synthetic bone grafts are known to fail under stress shield or are associated with systemic side effects. The purpose of the present study was to investigate and determine an already commercially available magnesium (Mg) alloy whose design is most suitable for long-term use. The mechanical properties of Mg1Ca and MgYREZr compared with normal cortical and cancellous bone were assessed. Another discussed aspect was the influence of the alloy in the graft fixation. The results revealed that Mg1Ca and MgYREZr alloys had a low tensile strength of 75 and 250 MPa, respectively. For this reason, it was surmised that MgYREZr alloy could be an optimal choice with favorable corrosion resistance. Since calcaneal fractures are prone to skin necrosis and septic complications, the need for antibacterial procedures and antibiotic prophylaxis is highlighted. Thus, an in vivo attempt was also made to identify the relationship between Mg alloy products and bacterial load. However, the most important feature of the present study was the creation of a 3D model grafting, with an anti-sliding design, which can be potentially used with the preferred Mg alloy in this type of fractures. In conclusion, artificial materials are the future in medicine, replacing the body-limiting capabilities of grafts. They are safe and incur less comorbidities. This method could pave the way for reducing patient discomfort and increasing patient satisfaction. Although further testing is required, this research represents a great starting point for calcaneal fractures.

Sural nerve harvest for infants: integrated with information based on anatomical dissections

Background/aim

The aim of the present study was to determine the course and possible variations of the sural nerve with all anatomical details in human fetal cadavers.

Materials and methods

This study was performed on 60 fetal cadavers. Formation type and level of the sural nerve was detected.

Results

According to trimesters, it was determined that the mean transverse and vertical distance between the lowest point of the LM and the SN varied between 1.1 and 2.9 mm and 1.54 and 3.58 mm, respectively. Type 2 was the most common seen type of sural nerve (35.83%). It was determined that the sural nerve was mostly formed at the middle third of the leg (42.5%).

Conclusion

Sural nerve graft with the knowledge of the anatomical details may be used for peripheral nerve reconstruction is required in congenital lesions, such as facial paralysis, obstetric brachial paralysis, and posttraumatic lesions in infants and children.

Clinical and Histological Differences between Guided Tissue Regeneration with Acellular Dermal Matrix of Porcine Origin and Autologous Connective Tissue: An Animal Study

This research aims to evaluate the clinical and histological parametric differences concerning keratinized tissue that result from two regeneration techniques, the subepithelial autologous connective tissue graft (ACTG) and the acellular dermal matrix (MD) of porcine origin, performed on surgical beds on edentulous spaces in an animal model. The parameters of the MD and ACTG groups were compared with samples of the control group (CG) after 15, 45, and 90 days. Nine female white pigs (Sus scrofa domestica) were used, and each animal provided 20 study areas (12 MD and 8 ACTG). At 15 days, the keratin layer thickness in the MD group was greater than those of the ACTG (25.27 vs. 19.95 μm) and the CG (21.2 μm). After 45 days, the MD and ACTG thickness values decreased but were higher than the CG. At 90 days, MD (19.46 μm) obtained a value close to that of CG, and the ACTG decreased to CG (15.53 μm, p < 0.001). The use of an MD may be a viable alternative to the ACTG because of its ability to provide increased keratinized tissue in comparison to the ACTG.

Therapeutic approach to electric burn with platelet rich plasma, grafts and hyperbaric oxygenation

Contact electrical burns are more severe than other forms of contact burn injury. Moreover, treatment of hand burns is an important therapeutic challenge. We present a 17 year-old female of low voltage electric hand injury, admitted 5 days after injury. The patient was treated with autologous platelet rich plasma, porcine dermis heterograft and partial autologous skin graft, all of them with hyperbaric oxygen therapy (HBOT) at 1.45 ATA "100% O2 like adjuvant therapy. Good evolution and acceptable aesthetic results were reported. Although more studies are required, we suggest that multi-therapeutic approach could be effective in treatment for electric burns in hands.

Divided Eyelid Nevus: Surgical Repair Discussion and Case Reports From Northwestern China

Currently, due to the lack of long-term postoperative follow-up outcomes of the congenital divided eyelid nevus, we described our surgical approaches and presented the functional and cosmetic results of 13 patients with an average of 5-year follow-up. Based on the surgical treatments and the follow-ups, the selection of total or subtotal excision depends on the lesion location and the use of blepharoplasty approaches is determined by defect size. The CO₂ laser may be a useful second-stage procedure to ablate remnant lesions, but long-term monitoring is required.

From Grafts to Human Bioengineered Vascularized Skin Substitutes

The skin plays an important role in the maintenance of the human's body physiological homeostasis. It acts as a coverage that protects against infective microorganism or biomechanical impacts. Skin is also implied in thermal regulation and fluid balance. However, skin can suffer several damages that impede normal wound-healing responses and lead to chronic wounds. Since the use of autografts, allografts, and xenografts present source limitations and intense rejection associated problems, bioengineered artificial skin substitutes (BASS) have emerged as a promising solution to address these problems. Despite this, currently available skin substitutes have many drawbacks, and an ideal skin substitute has not been developed yet. The advances that have been produced on tissue engineering techniques have enabled improving and developing new arising skin substitutes. The aim of this review is to outline these advances, including commercially available skin substitutes, to finally focus on future tissue engineering perspectives leading to the creation of autologous prevascularized skin equivalents with a hypodermal-like layer to achieve an exemplary skin substitute that fulfills all the biological characteristics of native skin and contributes to wound healing.

Validation of the Oswestry Risk of Knee Arthroplasty Index (ORKA-1) for Patients Undergoing Autologous Chondrocyte Implantation

OBJECTIVE

The purpose of this study was first to externally validate the Oswestry Risk of Knee Arthroplasty index (ORKA-1) by applying it to an autologous chondrocyte implantation (ACI) patient cohort in the United States with a broader definition of failure than only arthroplasty, and second, to determine predictive factors for the risk of ACI failure as defined by the senior author.

DESIGN

A total of 171 patients that underwent ACI were included to validate the ORKA-1 as all factors needed for calculation and outcomes were recorded. For Cox regression analysis, 154 patients were included as they completed preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner, Lysholm, International Knee Documentation Committee (IKDC), and 12-item Shor Form (SF-12) scores. Patient- and lesion-associated parameters were recorded for each patient.

RESULTS

At final follow-up (maximum of 10 years post-ACI), a total of 27 patients (15.8%) were considered a failure by senior author's definition. With ACI failure as endpoint, the mean survival was 7.96 years in risk group 1 and 5.4 years in risk group 5. Cox regression analysis identified preoperative KOOS Sport/Recreation as the only significant predictive factor for ACI failure (P = 0.007).

CONCLUSION

The ORKA-1 is a helpful tool for surgeons to estimate an individual patient's likelihood of ACI survival. Further studies with larger patient cohorts as well as a consensus definition of failure are needed to further refine predictors of ACI failure.

Diffusion Tensor Imaging for Quantitative Assessment of Anterior Cruciate Ligament Injury Grades and Graft

BACKGROUND

As the need for quantitative assessment of anterior cruciate ligament (ACL) injuries and ACL graft increases, diffusion tensor imaging (DTI) becomes a more valuable measuring tool. However, DTI changes in differing injury grades of ACL and longitudinal graft remain unclear.

PURPOSE

To investigate the diagnostic performance of DTI in quantitatively assessing ACL injury severity and the development of ACL grafts within 6 months of surgery.

STUDY TYPE

A cohort study.

SUBJECTS

Thirty-five patients diagnosed with grades I-IV ACL injuries and 20 volunteers as controls were recruited.

FIELD STRENGTH/SEQUENCE

T₁ -weighted, T₂ -weighted, proton density (PD)-weighted, and DTI at 3.0T MRI.

ASSESSMENT

ACL injury grades in arthroscopic images and DTI quantitative data were evaluated from July 2016 to July 2018.

STATISTICAL TESTS

Chi-square test, analysis of variance, Spearman correlation analysis, and receiver operator characteristic (ROC) curves.

RESULTS

Both fractional anisotropy (FA) (r = -0.898, P < 0.05) and apparent diffusion coefficient (ADC) (r = 0.851, P < 0.05) were significantly correlated with the severity of ACL injuries. The area under the curve (AUC) values for differentiation between low- and high-grade ACL injuries with FA and ADC were 0.973 and 0.963, respectively. Although there were no significant differences in FA (P > 0.05) and ADC (P > 0.05) between grades I and II ACL injuries or in ADC (P > 0.05) between grades III and IV, there were significant differences in FA and ADC between two grades (P < 0.05). There were significant differences in FA (P < 0.05) and ADC (P < 0.05) between normal ACL and 3-month graft postoperation, as well as in ADC values between 3-month and 6-month graft postoperation (P < 0.05).

DATA CONCLUSION

DTI could be used to quantitatively evaluate the ACL injury grades and the development of ACL grafts. The diagnostic efficiency of FA values was higher than that of ADC values.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 3.

A simple technique to reconstruct medium to large scalp defects with exposed bone

Medium to large scalp defects with exposed bone can pose particular challenges to the dermatologic surgeon. Most of the publications pertaining to the repair of such defects are presented in the plastic surgery literature. Dermatologic surgeons may have less experience in this area and be hesitant to pursue surgery when these defects may be encountered. The technique described below is a simple, one-stage reconstruction, with a short healing period, providing adequate cosmesis, and is within the capability of most dermatologic surgeons.

Periodontal regeneration by leukocyte and platelet-rich fibrin with autogenous bone graft versus enamel matrix derivative with autogenous bone graft in the treatment of periodontal intrabony defects: A randomized non-inferiority trial

BACKGROUND

Aim of the present study was to ascertain if a combination of leukocyte and platelet-rich fibrin (L-PRF) + autogenous bone graft (ABG) may be a clinically "non-inferior" treatment modality as compared with the association of enamel matrix derivative (EMD) with ABG in the management of intrabony defects (IBDs).

METHODS

A total of forty-four patients, exhibiting at least one unfavorable intraosseous defect, were treated by L-PRF associated with ABG (22 patients; test group) or EMD+ABG (control group) in each defect. At baseline and 12 months, a complete clinical and radiographic examination was done. Pre- and post-therapy clinical (probing pocket depth [PPD], clinical attachment level [CAL], gingival recession [GR]) and radiographic (defect Bone level [(DBL)] parameters for the different treatments were compared. To guarantee the test treatment's efficacy 1mm was chosen as non-inferiority margin; for clinical relevance, a second non-inferiority margin = 0.5 mm was set.

RESULTS

Clinical and radiographic parameters significantly improved 12 months after surgery in both test and control sites, without inter-groups differences for each measurement. The control group - test group differences for the parameters CAL gain -0.248 mm (-0.618 to 0.122), PPD Reduction -0.397 mm (-0.810 to 0.015), GR Change 0.059 mm (-0.300 to 0.418), DBL Gain -0.250 mm (-0.746 to 0.246) were all within the non-inferiority margin of 0.5 mm.

CONCLUSION

Our results suggest that the L-PRF+ABG combined treatment of non-contained IBDs produces non-inferior results in terms of CAL gain, PPD reduction, GR increase and DBL gain in comparison with the EMD+ABG combination.

Use of bacterial cellulose film for repair of bile duct injury in pigs

BACKGROUND/OBJECTIVE

The aim was to evaluate the use of bacterial cellulose film and bile duct autograft in repairing critical common bile duct injury in pigs.

METHODS

A prospective experimental analytical study was carried out on 20 Sus Domesticus, Piau suidae swine, divided into a control group (n = 10) and an experimental group (n = 10) divided into two subgroups: bacterial cellulose film E1 and bacterial cellulose film E2 to which bacterial cellulose film was randomly allocated. The control group underwent two complete critical common bile duct sections 10 mm apart, while the experimental group with a single critical common bile duct defect underwent a 10 mm section of the longitudinal shaft with edge resection. The defects in the control group were treated with end-to-end conventional anastomosis using polyglycolic 6-0 surgical thread and the experimental group with bacterial cellulose film by continuous suture using the same material. The animals were clinically evaluated throughout the experiment on days D150 (bacterial cellulose film E1), D225 (control group), and D330 (bacterial cellulose film E2) and by intraoperative ultrasound examination related to histopathological and biochemical findings.

RESULTS

The intraoperative ultrasonography detected the changes resulting from the common bile duct anastomosis in the control group that produced a considerable incidence of ductal narrowing and obstruction to the biliary flow. In the bacterial cellulose film E2 group, there was an increase in inflammation intensity, granulomatous reaction, fibrosis, and vessels density, without producing bile duct dilation in the ultrasonography assessment. Biochemical analysis of liver enzymes yielded results in the normal range confirming preservation of liver function at the different post-surgery time points.

CONCLUSION

Bacterial cellulose film, when used as a graft for bile duct repair, proved to be a biocompatible material that produced a complete healing process and biliary flow continuity.

Rebuilding the Interproximal Papilla: Description of "Tube" Technique and Two Case Reports

INTRODUCTION

Papilla reconstruction relies on similar principles as those applied to soft tissue grafting for recession defects; however, it is uniquely challenging from a surgical perspective because of the small size and lack of a blood supply. Several techniques have been used to reconstruct lost papilla; however, there are no prescribed techniques for this specific application.

CASE PRESENTATION

This report describes a novel technique, herein called, the "tube technique" for treating interproximal recession and reconstructing the interproximal papilla, and documents two cases using the tube technique. An increase in attachment levels was observed in Case 1 (5 mm) and in Case 2 (4 mm) after using this surgical technique for papilla reconstruction.

CONCLUSION

The tube grafting technique requires technical precision. Although when executed carefully, it results in predictable reconstruction of the interproximal papilla. Use of the tube technique helps mitigate issues associated with inadequate flap thickness, blood supply, and flap retraction.

In Vitro and In Vivo Preclinical Testing of Pericyte-Engineered Grafts for the Correction of Congenital Heart Defects

Background

We have previously reported the possibility of using pericytes from leftovers of palliative surgery of congenital heart disease to engineer clinically certified prosthetic grafts.

Methods and Results

Here, we assessed the feasibility of using prosthetic conduits engineered with neonatal swine pericytes to reconstruct the pulmonary artery of 9‐week‐old piglets. Human and swine cardiac pericytes were similar regarding anatomical localization in the heart and antigenic profile following isolation and culture expansion. Like human pericytes, the swine surrogates form clones after single‐cell sorting, secrete angiogenic factors, and extracellular matrix proteins and support endothelial cell migration and network formation in vitro. Swine pericytes seeded or unseeded (control) CorMatrix conduits were cultured under static conditions for 5 days, then they were shaped into conduits and incubated in a flow bioreactor for 1 or 2 weeks. Immunohistological studies showed the viability and integration of pericytes in the outer layer of the conduit. Mechanical tests documented a reduction in stiffness and an increase in strain at maximum load in seeded conduits in comparison with unseeded conduits. Control and pericyte‐engineered conduits were then used to replace the left pulmonary artery of piglets. After 4 months, anatomical and functional integration of the grafts was confirmed using Doppler echography, cardiac magnetic resonance imaging, and histology.

Conclusions

These findings demonstrate the feasibility of using neonatal cardiac pericytes for reconstruction of small‐size branch pulmonary arteries in a large animal model.

Use of Collagen Matrix Scaffolds as a Substitute for Soft Tissue Augmentation: Case Series

INTRODUCTION

The presence of keratinized mucosa (KM) around natural teeth is believed to be beneficial in certain restorative, prosthetic, and orthodontic situations. Lack of adequate KM is common and predictably treated by autogenous gingival grafts (AGGs); however, AGGs have the disadvantages of harvest site morbidity, limited donor site availability, and compromised esthetics.

CASE PRESENTATION

This case series presents the use of the xenogeneic porcine bilayer collagen matrix (BCM) in increasing the width of attached KM around natural teeth. Patients with a limited amount of KM, shallow vestibule, and aberrant frenum attachment were treated using this graft material. The patients were followed up to 4.5 years postoperatively and were evaluated regarding the amount of KM, gingival margin stability, and tissue esthetics.

CONCLUSIONS

Within the limitations of the sample size of patients in this report, the BCM appears to be a viable alternative option to AGG for increasing the width of KM gingiva around teeth. This method resulted in gain of KM, gingival margin stability, vestibular deepening, aberrant frenum elimination, and favorable esthetics in terms of color matching, texture, and contour blending. This xenogeneic graft material could be used in cases where the autogenous graft supply is limited or in highly esthetically demanding cases. Additionally, it could be an alternative option when a second surgical site is not desired by the patient or a less invasive procedure is preferred by the clinician in certain medical conditions. Well-controlled long-term studies are required to validate our limited clinical observations.

Treatment of Critical-Sized Calvarial Defects in Rats with Preimplanted Transplants

The local environment and the defect features have made the skull one of the most difficult regions to repair. Finding alternative strategies to repair large cranial defects, thereby avoiding the current limitations of autograft or polymeric and ceramic prostheses constitute an unmet need. In this study, the regeneration of an 8 mm critical-sized calvarial defect treated by autograft or by a monetite scaffold directly placed in the defect or preimplanted (either cranial bone transplant or subcutaneous pocket) and then transplanted within the bone defect is compared. The data reveal that transplantation of preimplanted monetite transplant scaffolds greatly improves the skull vault closure compared to subcutaneously preimplanted or directly placed materials. Autografts, while clearly filling the defect volume with bone appear effective since bone volume inside the defect volume is obviously high, but are not well fused to the skull. The preimplantation site has a large influence on the regeneration of the defect. Transplantation of induced bone inside materials has the potential to reduce the need for autograft harvest without damaging the skeleton. This first demonstration indicates that cranial repair may be possible without recourse to bioactives or cultured cell therapies.

Analyses of clinical and osteoimmunological parameters on keratinized mucosa around dental implants

Introduction

This study investigated the effects of keratinized mucosa width (KMW) on peri-implant tissues by evaluating peri-implant clinical and bone resorption parameters.

Subjects and Methods

Seventy-one dental implants (DIs) were separated based on adequacy/inadequacy of KMW. DIs with inadequacy KMW were grouped as peri-implant plastic surgery (PIPS) (free gingival graft/free periosteal graft groups) and maintenance (M) groups. DIs with adequacy KMW were grouped as the controls. Peri-implant clinical parameters were measured at the baseline and 6^th month. Levels of receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) in peri-implant sulcular fluid were determined after clinical measurements using enzyme-linked immunosorbent assay.

Results

In baseline, gingival index, bleeding on probing, and plaque index (PI) were lower in controls compared to the PIPS and M groups, and KMW was higher. At 6^th month, peri-implant pocket depth and PI were lower in the PIPS groups and controls compared to the M group, and KMW was higher. While RANKL and OPG values and RANKL/OPG ratio at baseline were not significantly different between groups, OPG concentration and RANKL/OPG ratio in the 6^th month were higher in the PIPS group compared to the M group (P < 0.05). The RANKL/OPG ratio decreased at 6^th month in the PIPS groups and controls (P < 0.05). Positive and negative correlations were observed between peri-implant clinical and osteoimmunological parameters.

Conclusion

This study demonstrated that adequate KMW and PIPS techniques exhibited positive effects on clinical peri-implant parameters and osteoimmunological mediators.

Effect of a Single Preoperative Dose of Oral Antibiotic to Reduce the Incidence of Surgical Site Infection Following Below-Knee Dermatological Flap and Graft Repair

Background

Surgical site infection (SSI) rates for below-knee dermatological surgery are unacceptably high, particularly following complex flap and graft closures. The role of antibiotic prophylaxis for these surgical cases is uncertain.

Objective

To determine whether SSI following complex dermatological closures on the leg could be reduced by antibiotic prophylaxis administered as a single oral preoperative dose.

Methods

A total of 115 participants were randomized to 2 g of oral cephalexin or placebo 40–60 minutes prior to surgical incision in a prospective, randomized, double-blind, placebo-controlled trial at a primary care skin cancer clinic in North Queensland, Australia.

Results

Overall 17/55 (30.9%) controls and 14/55 (25.5%) intervention participants developed infection (P = 0.525). There was no difference between the study groups in adverse symptoms that could be attributed to high-dose antibiotic administration (P = 1).

Conclusion

A single oral 2-g dose of cephalexin given before complex below-knee dermatological closure did not reduce SSI.