Reconstruction of traumatic tubular bone defects using vascularized fibular graft

Potential of periosteal cells in bone and cartilage regeneration: a systematic review

Introduction: The unavailability of adequate human primary cells presents multiple challenges in terms of bone and cartilage regeneration and disease modeling experiments in vitro. Periosteal cells (PCs), which represent promising skeletal stem cell sources, could be a promising strategy in tissue engineering. The present study aimed to summarize the characteristics of PCs to investigate the efficacy of these cells in bone and cartilage regeneration in different models, paying special attention to the comparison of bone marrow stromal cells (BMSCs). Methods: A comprehensive literature search was conducted in Embase, PubMed/MEDLINE, Web of Science, and Scopus for articles published in English until April 2023. Only original researches in which PCs were employed for bone or cartilage regeneration experiments were included. Results: A total of 9140 references were retrieved. After screening the results, 36 publications were considered to be eligible for inclusion in the present literature review. Overall, PCs demonstrated beneficial bone and cartilage regenerative efficacy compared to the bare scaffold since almost all included studies reported positive results. The 9 studies assessing the differences in bone formation capacity between PCs and BMSCs indicated that PCs exhibited stronger in vivo osteogenic differentiation capabilities compared to BMSCs, while the other study demonstrated stronger chondrogenic potential of BMSCs. Discussion: PCs demonstrated beneficial to bone regenerative efficacy compared to the bare scaffold with a low risk of most studies included. However, the cartilage formation capacity of BMSCs still needs to be investigated due to the limited research available and the certain risk of bias. PCs exhibited higher osteogenic capabilities compared to BMSCs in combination with various scaffolds in vivo with good evidence. Further researches are needed to elucidate the comparative benefits of cartilage regeneration. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023411522, CRD42023411522.

Fibula flap in upper extremity segmental/critical size bone defects fixed with locking plates. Single-institution observational cohort

INTRODUCTION

Management of bone defects in the upper extremity can vary depending on the size and location of the defect. Large defects may require complex reconstruction techniques. Vascularized bone grafts, mainly free vascularized fibula flap (FVFF), have many advantages in the treatment of bone or osteocutaneous defects. However, complications such as graft fracture are the most common, with a free fibula flap for bone defects in the upper extremity. This study aimed to describe the results and complications associated with the treatment of posttraumatic bone defects in the upper extremity using FVFF. We hypothesized that performing osteosynthesis using locking plates would prevent or reduce the fracture of the fibula flap MATERIALS AND METHODS: This was a retrospective single-centre cohort study. Patients with segmental bone defects caused by trauma who underwent reconstructive surgery with FVFF fixed with locking compression plates (LCP) between January 2014 and 2022 were included. Demographic variables and preoperative data, such as bone defect, location, and time until reconstruction, were collected. Bone defects were classified according to the Testworth classification. Intraoperative variables included the length of the FVFF, type of graft (osteocutaneous or not), type and technique of arterial and venous sutures, number of veins used as output flow, and the osteosynthesis technique used.

RESULTS

Ten patients were included (six humerus, three ulna, and one radius). All patients had critical-size bone defects, and nine patients had a history of infection. In 9 of 10 patients, bone fixation was performed with a bridge LCP and in one patient with two LCP plates. In eight cases, the FVFF was osteocutaneous. All the patients showed bone healing at the end of the follow-up period. There was one early complication, donor site wound dehiscence, and two long-term complications (proximal radioulnar synostosis and soft-tissue defect).

CONCLUSION

A high rate of bone union with a low rate of complications can be obtained with an FVFF in upper extremity segmental/critical-size bone defects. Rigid fixation with locking plates avoids stress fractures of the grafts, mainly in humeral reconstruction. However, in these cases, a bridge plate should be used.

The Pedicled Fibula Flap for Lower Limb Reconstruction

The pedicled fibula flap is a reliable technique to treat large defects in the tibia. Despite increasing evidence of its efficacy and good long-term outcomes, a knowledge gap exists in its indications and technique. This instructional article presents a comprehensive overview of the indications, pre-operative planning, step-by-step surgery, and subsequent post-operative management.

How to cite this article

Noorlander-Borgdorff MP, Giannakópoulos GF, Winters HAH, et al. The Pedicled Fibula Flap for Lower Limb Reconstruction. Strategies Trauma Limb Reconstr 2023;18(3):186-193.

Adipose stem cells-derived exosomes modified gelatin sponge promotes bone regeneration

Background: Large bone defects resulting from trauma and diseases still a great challenge for the surgeons. Exosomes modified tissue engineering scaffolds are one of the promising cell-free approach for repairing the defects. Despite extensive knowledge of the variety kinds of exosomes promote tissue regeneration, little is known of the effect and mechanism for the adipose stem cells-derived exosomes (ADSCs-Exos) on bone defect repair. This study aimed to explore whether ADSCs-Exos and ADSCs-Exos modified tissue engineering scaffold promotes bone defects repair. Material/Methods: ADSCs-Exos were isolated and identified by transmission electron microscopy nanoparticle tracking analysis, and western blot. Rat bone marrow mesenchymal stem cells (BMSCs) were exposed to ADSCs-Exos. The CCK-8 assay, scratch wound assay, alkaline phosphatase activity assay, and alizarin red staining were used to evaluate the proliferation, migration, and osteogenic differentiation of BMSCs. Subsequently, a bio-scaffold, ADSCs-Exos modified gelatin sponge/polydopamine scaffold (GS-PDA-Exos), were prepared. After characterized by scanning electron microscopy and exosomes release assay, the repair effect of the GS-PDA-Exos scaffold on BMSCs and bone defects was evaluated in vitro and in vivo. Results: The diameter of ADSCs-exos is around 122.1 nm and high expressed exosome-specific markers CD9 and CD63. ADSCs-Exos promote the proliferation migration and osteogenic differentiation of BMSCs. ADSCs-Exos was combined with gelatin sponge by polydopamine (PDA)coating and released slowly. After exposed to the GS-PDA-Exos scaffold, BMSCs have more calcium nodules with osteoinductive medium and higher expression the mRNA of osteogenic related genes compared with other groups. The quantitative analysis of all micro-CT parameters showed that GS-PDA-Exos scaffold promote new bone formed in the femur defect model in vivo and confirmed by histological analysis. Conclusion: This study demonstrates the repair efficacy of ADSCs-Exos in bone defects, ADSCs-Exos modified scaffold showing a huge potential in the treatment of large bone defects.

Clinical Efficacy and Safety Analysis of Levofloxacin for the Prevention of Infection after Traumatic Osteoarthrosis and Internal Fixation: Systematic Review and Meta-Analysis

Objective

Levofloxacin has been widely used in clinical anti-infection treatment; however, its adverse reactions to levofloxacin were also obvious in patients. Herein we aimed to systematically evaluate the clinical efficacy and safety of systemic administration of levofloxacin in the prevention of postoperative infection after traumatic osteoarthrosis and internal fixation.

Methods

PubMed, Cochrane Library, OVID, EBSCO, CNKI, VIP database, and Wanfang Database were searched from December 1993 to December 2021. Meanwhile, China ADR Information Bulletin and WHO Pharmaceutical were searched manually. Newsletter and FDA Drug Safety Newsletter, also to retrieve the Websites of Chinese, Chinese, and drug regulatory authorities; To obtain data on adverse events in children with systemic administration of levofloxacin. The literature was screened according to inclusion and exclusion criteria. The risk of bias was evaluated for the included RCT literature.

Results

There was a statistical difference in the comparison of the incidence of fever between the experimental group and the control group (OR = 2.29, 95% CI (1.75,2.98),P < 0.00001, I² = 0%, Z = 6.11); elevated white blood cell count (OR = 1.82, 95% CI (1.31,2.52),P=0.0003, I² = 0%, Z = 3.60); incidence of wound infection (OR = 2.11, 95% CI (1.54,2.90),P < 0.00001, I² = 0%, Z = 4.64); adverse drug reaction (OR = 1.82, 95% CI (1.21,2.74),P=0.004, I² = 0%, Z = 2.86).

Conclusion

In the clinical use of levofloxacin, adverse drug reactions including fever, elevated white blood cell count, and wound infection should be concerned.

A systematic review of bone marrow stromal cells and periosteum-derived cells for bone regeneration

Bone marrow stromal cells (BMSCs) and periosteum-derived cells (PDCs) represent promising skeletal stem cell sources to treat critical-size bone defects. However, the large number of preclinical tests with a variety of in vivo data complicates the selection of cells for further clinical translation. This systematic review aims to analyze the in vivo bone-forming efficacy of BMSCs- and PDCs-based approaches in all published preclinical experiments until November 2020. For this purpose, four databases (PubMed, Embase, Cochrane Central Register of Controlled Trial, and Web of Science) were searched for eligible literature, which yielded a total of 94 full-text articles for systematic review. This review generated an evidence-based list of BMSC- or PDC-based approaches, which have been evaluated for bone formation in different animal models. Among them, 74 studies were included for pairwise and network meta-analysis. The results revealed that both PDC and BMSC had beneficial bone-forming efficacy compared to bare scaffold. In addition, BMSC- and PDC-based approaches had no significant difference regarding in vivo bone-forming efficacy. However, BMSC-based approach had a higher probability to be ranked better than PDC-based approach. Furthermore, the review discusses (i) the possible risk of bias of the in vivo evaluation of cell-based approaches, (ii) the difficulty in replication of such experiments due to frequent poor reporting of the methods and results, and (iii) the clinical relevance of the currently utilized BMSC- and PDC-based approaches. Systematic review registration: The study was prospectively registered in PROSPERO, Registration No. CRD42021270922.

The efficacy of combining a vascularized biogenic conduit and a decellularized nerve graft in the treatment of peripheral nerve defects: An experimental study using the rat sciatic nerve defect model

BACKGROUND

Although decellularized nerve grafts are often used as a bridging material in nerve defect repair, the lack of perfusion support in this procedure limits the regeneration capacity. To address this, we applied vascularized biogenic conduits, which are fibrous membranes prefabricated around the silicone rod that contain rich vascularity and macrophages, to nerve defect repair procedures using decellularized nerve grafts. The purpose of this study is to investigate the capacity of combining a vascularized biogenic conduit and a decellularized nerve graft for peripheral nerve regeneration using a 10-mm nerve defect model in rats.

MATERIALS AND METHODS

Sixteen adult male rats (F344 rats, 10-12 weeks, 200-250 g) were used in this study. For the prefabrication of vascularized biogenic conduits, a silicone rod was transplanted next to the sciatic nerve. After 8 weeks, this silicone rod was enveloped in connective tissue, called a vascularized biogenic conduit. The first rat was used to investigate the histological characteristics of vascularized biogenic conduits through immunofluorescence studies. The remaining 15 rats were divided into three groups to evaluate the efficacy of the combination of a decellularized nerve graft and a vascularized biogenic conduit: a decellularized nerve graft (DNG) group, a decellularized nerve graft with a vascularized biogenic conduit (DNG-w-VBC) group, and an autologous nerve graft (ANG) group. Eight weeks after nerve graft surgery, the assessment results of both functional recovery (electrophysical studies and target muscle atrophy) and morphological recovery (total number, diameter, and myelin thickness of the regenerated axons) of the regenerated nerves were examined.

RESULTS

Immunofluorescence studies revealed that the VBC contains extracellular matrix, vascular tissue, and macrophages. The results of the DNG-w-VBC group were superior to the DNG group in electrophysiological studies (CMAP; 6.29 ± 0.80% vs. 4.02 ± 3.35%, MNCV; 50.6 ± 8.4% vs. 25.7 ± 15.6%, p < .05, respectively), regenerated axon number (11,348 ± 812 vs. 7697 ± 2197, p < .05), and mean axon diameter (2.72 ± 0.33 μm vs. 1.64 ± 0.12 μm, p < .05).

CONCLUSIONS

Our study confirms that vascularized biogenic conduits supply vascularity and macrophages to nerve defect sites. Combining vascularized biogenic conduits with decellularized nerve grafts to treat nerve defects offers superior functional and morphological recovery of regenerated axons.

Vascularized bone grafts for post-traumatic defects in the upper extremity

Vascularized bone grafts (VBGs) are widely employed to reconstruct upper extremity bone defects. Conventional bone grafting is generally used to treat defects smaller than 5–6 cm, when tissue vascularization is adequate and there is no infection risk. Vascularized fibular grafts (VFGs) are mainly used in the humerus, radius or ulna in cases of persistent non-union where traditional bone grafting has failed or for bone defects larger than 6 cm. Furthermore, VFGs are considered to be the standard treatment for large bone defects located in the radius, ulna and humerus and enable the reconstruction of soft-tissue loss, as VFGs can be harvested as osteocutaneous flaps. VBGs enable one-stage surgical reconstruction and are highly infection-resistant because of their autonomous vascularization. A vascularized medial femoral condyle (VFMC) free flap can be used to treat small defects and non-unions in the upper extremity. Relative contraindications to these procedures are diabetes, immunosuppression, chronic infections, alcohol, tobacco, drug abuse and obesity. The aim of our study was to illustrate the use of VFGs to treat large post-traumatic bone defects and osteomyelitis located in the upper extremity. Moreover, the use of VFMC autografts is presented.

Managing bone loss in open fractures

Segmental bone loss continues to pose substantial clinical and technical challenges to orthopaedic surgeons. While several surgical options exist for the treatment of these complex patients, there is not a clear consensus or specific guidelines on the optimal management of these injuries as a whole. Many factors must be taken into consideration when planning surgery for these individuals. In order for these techniques to yield optimal results, each injury must be approached in a step-wise and multidisciplinary fashion to ensure that care is taken in bone and wound bed preparation, that soft tissues are healthy and free of contaminants, and that the patient's medical condition has been optimized. Through this article, we will answer relevant questions and discuss common obstacles and challenges encountered with these complex injuries. We will also review the many treatment options available or in development to address this problem.