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

MiR-26b-5p/TET3 regulates the osteogenic differentiation of human bone mesenchymal stem cells and bone reconstruction in female rats with calvarial defects

BACKGROUND

MicroRNAs (miRNAs) play critical roles in the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs), but the mechanism by which miRNAs indirectly modulate osteogenesis remains unclear. Here, we explored the mechanism by which miRNAs indirectly modulate gene expression through histone demethylases to promote bone regeneration.

METHODS AND RESULTS

Bioinformatics analysis was performed on hBMSCs after 7 days of osteogenic induction. The differentially expressed miRNAs were screened, and potential target mRNAs were identified. To determine the bioactivity and stemness of hBMSCs and their potential for bone repair, we performed wound healing, Cell Counting Kit-8 (CCK-8), real-time reverse transcription quantitative polymerase chain reaction (RT‒qPCR), alkaline phosphatase activity, alizarin red S (ARS) staining and radiological and histological analyses on SD rats with calvarial bone defects. Additionally, a dual-luciferase reporter assay was utilized to investigate the interaction between miR-26b-5p and ten-eleven translocation 3 (TET3) in human embryonic kidney 293T cells. The in vitro and in vivo results suggested that miR-26b-5p effectively promoted the migration, proliferation and osteogenic differentiation of hBMSCs, as well as the bone reconstruction of calvarial defects in SD rats. Mechanistically, miR-26b-5p bound to the 3' untranslated region of TET3 mRNA to mediate gene silencing.

CONCLUSIONS

MiR-26b-5p downregulated the expression of TET3 to increase the osteogenic differentiation of hBMSCs and bone repair in rat calvarial defects. MiR-26b-5p/TET3 crosstalk might be useful in large-scale critical bone defects.

Novel Approach to Difficult Spinal Reconstruction: Bilateral Simultaneous Rib and Iliac Crest Vascularized Bone Graft Spinoplastic Surgery

Pseudoarthrosis is a severe complication of spinal fusion surgery with occurrence rates as high as 35%-40%. Current options of revision surgery to correct pseudoarthrosis frequently carry high failure rates and risk of developing junctional kyphosis. Pedicled vascularized bone grafts (VBGs) are an innovative approach to boost spinal fusion rates via improving structural integrity and increasing the delivery of blood to the donor site. This versatile technique can be performed at different spinal levels without additional skin incisions and with minimal added operative time. Here we present the first bilateral rib and iliac crest VBG spinoplastic surgery performed to augment spinal fusion in a 68-year-old woman with distal junctional kyphosis and severe positive sagittal balance with low back and neck pain and significant difficulty standing upright. The patient had history of multiple spinal operations with preoperative CT imaging demonstrating loosening and pull out of L3 and fracture of L2 screws. She underwent two-stage surgical treatment involving anterior lumbar interbody fusion L3-S1 followed by removal of hardware, T4 to pelvis fusion with L2-3 prone lateral interbody fusion, and T11-S1 posterior column osteotomies. The surgery was augmented by bilateral rib and iliac crest VBGs performed by plastic surgery. At three-month follow-up the patient demonstrated functional improvement, being able to maintain upright posture and walk; was satisfied with the result of the surgery; and demonstrated no graft-related complications. In conclusion, utilization of pedicled VBGs is a novel, promising approach to augment spinal surgery in high risk patients.

Reconstruction With Flow-Through Chimeric Anterolateral Thigh Flap Combining Vascularized Fibular Bone Graft for Extensive Composite Tissue Defect of the Forearm: A Case Report

ABSTRACT

The management of critical limb trauma is challenging because limb salvage is preferable to amputation. For upper limb reconstruction, the surgical restoration of functionality, and appearance, a multidisciplinary approach is needed. We report the case of an extensive composite tissue defect of the forearm caused by a machine-crushing injury that was repaired by a flow-through chimeric anterolateral thigh flap with a vascularized fibular graft. Reconstruction was performed as a single-stage procedure; no complications occurred, and both functional and aesthetic outcomes were satisfactory.

Non-vascularised corticocancellous (tricortical) iliac bone graft longer than 3 cm for non-union after failed surgical treatment

PURPOSE

We hypothesised that traditional iliac tricortical bone grafts (no vascularised) still have a reasonable role in promoting satisfactory bony healing in non-union defects of certain sizes. Here, we report the clinical/radiological outcomes through a retrospective case series.

METHODS

We screened 74 patients with definitive non-union in the long bones of the upper extremities who visited the outpatient department from 2008 to 2018. Among these patients, 25 who met our inclusion/exclusion criteria were investigated.

RESULTS

The mean age was 51.92 years, and there were 12, 9, 1, and 3 lesions of the radius, ulna, clavicle, and humerus, respectively. The tools for primary fixations were plate and intramedullary nails in 24 and 1 patients, respectively. Six patients presented with atrophic non-union. The mean period from a previous surgery was 6.84 months. The mean defective bone sizes were 1.81 and 3.50 cm pre-debridement and post-debridement, respectively. All devices had locking plates longer than the previous plate, and the graft was concurrently fixed by screws in three patients. At a mean of 15.92 weeks after the revision surgery, all patients experienced union. At the final follow-up, the clinical outcomes were satisfactory. No significant differences in clinical outcomes were found according to the lesion, type of non-union, period from the previous surgery, or harvest length of the iliac bone.

CONCLUSIONS

If the proper indications and some technical aspects are considered, a non-vascularised iliac bone graft longer than 3 cm could still be a reasonable option for treating diaphyseal non-union of the upper extremities.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Osteocutaneous Radial Forearm Flap: Harvest Technique and Prophylactic Volar Locked Plating

Background

The osteocutaneous radial forearm (OCRF) flap is a variation of the traditional radial forearm flap with incorporation of an anterolateral segment of corticocancellous bone of the radius, periosteum, and overlying skin. The OCRF flap is indicated in traumatic injuries or extirpation defects with segmental bone loss and is well suited to foot and ankle reconstruction due to its thin pliable skin.

Methods

In this single-center case series, a retrospective review was conducted to identify patients who underwent OCRF free flap for foot and ankle reconstruction that required harvest of more than 50% of the cross-sectional area of the radius with prophylactic volar locked plating of the donor site. Outcome measures included flap failure rates, postoperative fracture, thrombotic events, time to follow-up, and time to full weightbearing. Flap harvest technique is extensively discussed.

Results

Six cases were included in this series. There were no flap failures or thrombotic events. Recipient site healing was confirmed in all patients, with partial distal skin paddle loss in one patient requiring operative debridement. No patients sustained donor site complications or functional impairment. Full lower extremity weightbearing was achieved at 12.4 ± 3.3 weeks after surgery.

Conclusions

The OCRF free flap transfer provides a reliable means of obtaining thin, supple soft tissue coverage with a large, vascularized segment of bone for reconstruction in the foot and ankle. Here, we describe use of more than 50% of the cross-sectional area of the radius with volar locked prophylactic plating. These updates expand use of this reconstructive technique.

Vascularized Bone Grafting Versus the 2-Stage Masquelet Technique for Upper-Extremity Bone Reconstruction: A Meta-Analysis

PURPOSE

Vascularized bone grafting (VBG) has been described as the technique of choice for larger bone defects in bone reconstruction, yielding excellent results at the traditional threshold of 6 cm as described in the literature. However, we hypothesize that the 2-stage Masquelet technique provides equivalent union rates for upper-extremity bone defects regardless of size, while having no increase in the rate of patient complications.

METHODS

A systematic literature review was conducted using PubMed and Scopus for outcomes after VBG and the Masquelet technique for upper-extremity bone defects of the humerus, radius, ulna, metacarpal, or phalanx (carpal defects were excluded). A meta-analysis was performed to compare outcomes following VBG and the Masquelet technique at varying defect sizes.

RESULTS

There were 77 VBG (295 patients) and 25 Masquelet (119 patients) studies that met inclusion criteria. Patients undergoing the Masquelet technique had defect sizes ranging from 0-15 cm (average 4.5 cm), while patients undergoing VBG had defect sizes ranging from 0-24 cm (average 5.9 cm). The union rate for Masquelet patients was 94.1% with an average time to union of 5.8 months, compared to 94.9% and 4.4 months, respectively, for VBG patients. We did not identify a defect size threshold at which VBG demonstrated a significantly higher union rate. No statistically significant difference was found in union rates between techniques when using multivariable logistic regression analysis.

CONCLUSION

There was no statistically significant difference in union rates between VBG and the Masquelet technique in upper-extremity bone defects regardless of defect size. Surgeons may consider the Masquelet technique as an alternative to VBG in large bone defects of the upper extremity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The Use of Free Fibula Flap in Different Extremities and Our Clinical Results

Background and objectives Plastic, orthopedic, otolaryngology, and oromaxillofacial surgery specialists rely on fibula grafts to solve reconstructive problems. The aim of this study is to discuss the use and results of vascular fibula flaps in the treatment of bone and soft tissue defects in various regions with different etiologies. Materials and methods In our clinic, we treated 32 patients with osteocutaneous fibular flaps due to bone and soft tissue defects of different etiologies and varying anatomical regions. In our study, age, gender, side, cause of injury, surgical technique, treatment results, and complications were evaluated for each patient. Results Of the 32 patients, 25 were male, and 7 were female. The average age is 37.2 (27-56). The mean bone defect size was 10.45 cm. Bone defect occurred in eight patients due to osteomyelitis, eleven patients due to gunshot wounds, nine patients due to pseudoarthrosis, and four patients due to a giant cell tumor. We applied osteocutaneous fibula flap in 27 patients and vascularized fibular flap in five patients. Bone union could not be achieved in four patients, and bone grafting was performed as a secondary surgery. Local infection occurred in five patients, and their treatment was completed with debridement and antibiotic administration. Wound complications occurred in three patients at the donor site, which were treated with debridement and skin grafting. The mean duration of radiological union was three months, and complete union was achieved in the seventh month. Conclusions We have shown in our case series that free vascularized fibula transfer has gained an important place in the field of skeletal reconstruction and is a reliable method for various bone reconstructions.

Vascularized Bone Graft Reconstruction for Upper Extremity Defects: A Review

Upper extremity reconstruction may pose clinical challenges for surgeons due to the often-critical, complex functional demands of the damaged and/or missing structures. The advent of vascularized bone grafts (VBGs) has aided in reconstruction of upper extremity (UE) defects due to their superior regenerative properties compared with nonvascularized bone grafts, ability to reconstruct large bony defects, and multiple donor site options. VBGs may be pedicled or free transfers and have the potential for composite tissue transfers when bone and soft tissue are needed. This article provides a comprehensive up-to-date review of VBGs, the commonly reported donor sites, and their indications for the treatment of specific UE defects.

Free Vascularized Fibular Flap with Bilateral Bipolar Latissimus Transfer for Upper Extremity Reconstruction: A Case Report

CASE

A 19-year-old woman presented with bilateral mangled upper extremities after jumping in front of a moving train. After revascularization, osteocutaneous free vascularized fibula flap was performed to reconstruct the right humerus. The left forearm required transradial amputation with acute targeted muscle reinnervation. Finally, staged bilateral bipolar latissimus dorsi functional muscle flaps were performed to restore elbow flexion.

CONCLUSION

Staged orthoplastic reconstruction of the upper extremities is an effective treatment approach for traumatic bone and soft-tissue defects. This patient's recovery demonstrates improved quality of life after severe upper extremity trauma.

Treatment of Recalcitrant Femoral Shaft Nonunion With Medial Femoral Condyle Pedicled Autograft: Technical Trick

SUMMARY

Nonunited fractures of the femoral shaft and distal femur are usually successfully addressed with stabilization with or without autogenous bone grafting. For the small subset of these problems that prove recalcitrant to front-line treatment, a pedicled medial femoral condyle (MFC) bone flap can provide a source of vascularized autograft with minimal donor site morbidity. The MFC has gained recent widespread adoption as a free vascularized bone transfer, and here, we present a surgical technique and retrospective analysis of patients treated with a pedicled MFC technique. This serves as a useful treatment option for these difficult problems and may be especially helpful in low resource environments or where microsurgical anastomosis is not feasible.

[Reconstruction in polytraumatized burn patients]

BACKGROUND

Polytraumatized burn patients represent a rare patient collective and necessitate an individualized treatment concept due to the particular combination of injuries.

OBJECTIVE

Against the background of this special injury pattern, especially with deep burns overlying the fracture zone, the question of a specific and interdisciplinary treatment algorithm arises.

MATERIAL AND METHODS

This article is based on a PubMed database search and experiences of a trauma center for severely injured burn patients at a university hospital, with presentation of the special therapeutic requirements and goals exemplified by a case report.

RESULTS

The evaluation of the literature search and own treatment results comes to the conclusion that the rate and extent of amputations and infections can be reduced by an early and interdisciplinary involvement of the plastic surgeon by early combined fracture stabilization, excision of necrotic tissue and immediate skin grafting. Furthermore, plastic reconstructive procedures enable a functional and esthetic reconstruction with optimized prosthesis fitting.

CONCLUSION

Polytraumatized severely burned patients necessitate an interdisciplinary treatment approach, whereby preservation of length, functionality and esthetic appearance of the affected extremities and concurrent avoidance of bone and soft tissue infections have utmost priority.