There is a role for allografts in reconstructive surgery of the elbow and forearm

Allografts use in orthopedic surgery: trend change over the past 11 years from a regional tissue bank

Allografts are the second most transplanted tissue in medicine after blood and are now increasingly used for both primary and revision surgery. Allografts have the advantages of lower donor site morbidity, availability of multiple grafts, and shorter operative time. The Banks represents the bridge between Donor and Recipient and guarantees the quality and safety of the distributed allografts Given the increasing interest in these tissues, a retrospective analysis of data collected from the Regional Musculoskeletal Tissue Bank registry over an 11-year period (2009-2019) was conducted. The statistical analyses used were the Shapiro-Wilk normality test and a Poisson regression model. From January 2009 to December 2019, a total of 14,199 musculoskeletal tissues stored in the Regional Musculoskeletal Tissue Bank were provided for surgical allograft procedures. In 2009, the number of allografts performed was 925; this figure has steadily increased to 1599 in 2019. Epiphyses were taken as the reference tissue with an almost constant trend over the period, while a significant increase was denoted for extensor mechanism allograft, ligaments, tendons and long bone corticals (p < 0.001), processed bone tissues had no change in trend (p = 0.841). There was also a gradual decrease in the rate of microbiological positivity, as determined by bacteriological and serological tests performed on the collected tissues. This phenomenon is due to improved sampling techniques and the training of a dedicated team. Thus, we have seen how the use of allografts in orthopedic surgery has increased over the past 11 years, uniformly in terms of tissue type, except for the noticeable increase in ligamentous tissue.

Outcomes of management of primary benign aggressive or malignant bone tumors around the elbow by limb-salvage surgery

PURPOSE

Bone tumors around the elbow are rare, with frequently delayed diagnosis. The current study aimed to assess the functional and oncological outcomes of limb salvage surgery for primary benign aggressive or malignant bone tumors around the elbow.

METHODS

We conducted a retrospective review of patients with primary aggressive benign and malignant bone tumors around the elbow treated with limb salvage surgery between 1995 and 2020 at a single musculoskeletal oncology center. The minimum follow-up period was 24 months. Functional results were assessed using the Musculoskeletal Tumor Society (MSTS) scoring system at the last follow-up visit. Local recurrence, chest metastasis, and complications were recorded.

RESULTS

This study included 30 patients, 19 males and 11 females, with a mean age of 25.4 ± 14.2 years. The tumor location was the distal humerus (n = 21), proximal radius (n = 5), and proximal ulna (n = 4). Reconstruction was done by elbow fusion using fibular graft (n = 10), mobile endoprosthesis (n = 9), excision arthroplasty (n = 7), and extracorporeal freezing and reimplantation (n = 4). The mean follow-up period was 36.2 ± 21.3 months. The median follow-up MSTS score was 27 [Interquartile range (IQR): 26-30]. Skeletally immature patients had a significantly higher MSTS score. The rate of postoperative complications was 26.7%.

CONCLUSION

Limb salvage surgery with different reconstructive options for benign aggressive and malignant bone tumors around the elbow can achieve good functional and oncological outcomes.

LEVEL OF EVIDENCE

Level IV.

Exosomes derived from mesenchymal stromal cells promote bone regeneration by delivering miR-182-5p-inhibitor

Exosomes, small extracellular vesicles that function as a key regulator of cell-to-cell communication, are emerging as a promising candidate for bone regeneration. Here, we aimed to investigate the effect of exosomes from pre-differentiated human alveolar bone-derived bone marrow mesenchymal stromal cells (AB-BMSCs) carrying specific microRNAs on bone regeneration. Exosomes secreted from AB-BMSCs pre-differentiated for 0 and 7 days were cocultured with BMSCs in vitro to investigate their effect on the differentiation of the BMSCs. MiRNAs from AB-BMSCs at different stages of osteogenic differentiation were analyzed. BMSCs seeded on poly-L-lactic acid(PLLA) scaffolds were treated with miRNA antagonist-decorated exosomes to verify their effect on new bone regeneration. Exosomes pre-differentiated for 7 days effectively promoted the differentiation of BMSCs. Bioinformatic analysis revealed that miRNAs within the exosomes were differentially expressed, including the upregulation of osteogenic miRNAs (miR-3182, miR-1468) and downregulation of anti-osteogenic miRNAs (miR-182-5p, miR-335-3p, miR-382-5p), causing activation of the PI3K/Akt signaling pathway. The treatment of BMSC-seeded scaffolds with anti-miR-182-5p decorated exosomes demonstrated enhanced osteogenic differentiation and efficient formation of new bone. In conclusion, Osteogenic exosomes secreted from pre-differentiated AB-BMSCs were identified and the gene modification of exosomes provides great potential as a bone regeneration strategy. DATA AVAILABILITY STATEMENT: Data generated or analyzed in this paper partly are available in the GEO public data repository(http://www.ncbi.nlm.nih.gov/geo).

Proximal Humeral Replacement With Osteoarticular Allograft Prosthetic Composite in Failed Revision Total Elbow Arthroplasty With Marked Bone Loss

Total elbow arthroplasty (TEA) procedures are becoming more prevalent with an associated increase in revision procedures. Revision TEA in the setting of marked bone loss poses a challenge for the treating surgeon. We present a viable surgical option for patients with extensive proximal humeral bone loss treated with proximal humerus osteoarticular allograft prosthetic composites prepared with intact rotator cuff, pectoralis, and deltoid soft tissue attachments along with a rehabilitative protocol and follow up. Revision techniques involving the use of strut allografts and allograft prosthetic composites have previously been described in the distal humerus, but none to our knowledge have been published regarding composite allograft replacement of the proximal humerus in in combination with a TEA.

The potential of radiation sterilized and banked tissue allografts for management of nuclear casualties

Processed and radiation sterilized allograft tissues that can be banked for use on demand are a precious therapeutic resource for the repair or reconstruction of damaged or injured tissues. Skin dressings or skin substitutes like allograft skin, amniotic membrane and bioengineered skin can be used for the treatment of thermal burns and radiation induced skin injuries. Bone grafts can be employed for repairing fracture defects, filling in destroyed regions of bone, and treatment of spinal and joint injuries. A nuclear scenario would result in a large number of casualties due to the heat, blast and radiation effects of the weapon. Perspective of radiation sterilized biological tissues provided by the tissue banks for management of casualties in a nuclear disaster scenario is presented.

Subtrochanteric femoral fracture with postoperative chronic osteomyelitis treated successfully by 1-stage operation: a case report

Chronic osteomyelitis is a chronic infectious disease of bone tissue, which can cause necrosis of bone and surrounding soft tissue, and is a common complication of open fracture, internal fixation, diabetic foot and blood-borne bone infection. Traumatic osteomyelitis is caused by bone tissue infection after open fracture surgery or open reduction of fracture or other bone and joint surgery. The lesion is near the fracture end. Intramedullary infection is the most serious infection in acute stage, with high fever, chills and other toxemia symptoms, similar to acute hematogenous osteomyelitis. The other is the skin and muscle necrosis infection near the fracture, which makes Fractures that lose blood supply are exposed to air and become dry and necrotic, and the course of disease turns to chronic, often accompanied by infectious nonunion or bone damage. The course of disease is prolonged and the treatment is difficult. Subtrochanteric femoral fracture with postoperative chronic osteomyelitis is a rare condition requiring complex treatment. In the present study, we report on a 49-year-old male patient who received open reduction with intramedullary nail fixation due to subtrochanteric femoral fracture, but later suffered postoperative infection and developed chronic osteomyelitis. On the basis of the complete removal of the osteomyelitis lesion, we performed a 1-stage operation where free vascularized fibula was used to repair the bone defect, followed by effective internal fixation. The patient was followed up for 24 months and finally recovered from chronic osteomyelitis, with good functional recovery of the hip joint and a Harris score of 85.

Rabbit umbilical cord mesenchymal stem cells: A new option for tissue engineering

BACKGROUND

The source and availability of cells for tissue engineering in large scale research or clinical trials requires special attention. We propose the idea of applying rabbit umbilical cord mesenchymal stem cells for this purpose.

METHODS

Here, the structure of the rabbit umbilical cord was analyzed and compared to that of human umbilical cord, both macroscopically and histologically. Next, we isolated, cultured and identified the proliferative activity and immunological characteristics of rabbit umbilical cord mesenchymal stem cells in vitro using mixed lymphocyte reaction, flow cytometry and an enzyme-linked immunosorbent assay. Furthermore, we evaluated the effects of biphasic calcium phosphate ceramic scaffolds seeded with rabbit umbilical cord mesenchymal stem cells in rat cranial defect models using multiple techniques, including radiological, histological and immunohistochemistry.

RESULTS

In vitro studies demonstated a high level of proliferation and multi-lineage differentiation potential in rabbit umbilical cord mesenchymal stem cells. Rabbit umbilical cord mesenchymal stem cells exibited low immunogenicity properties and immune suppression capability with respect to both the allogeneic and xenogeneic immune response. The results of the in vivo study showed that rabbit umbilical cord mesenchymal stem cells could promote osteogenesis in heterogeneous hosts.

CONCLUSIONS

The rabbit umbilical cord mesenchymal stem cells may be a new source for tissue engineering.