No abstract

Giant cell tumor is a relatively uncommon but painful tumor of bone, which can metastasize to the lungs. The RANK pathway is often reported to be involved in the pathogenesis of giant cell tumor of bone (GCTB). This pathway is a key signaling pathway of bone remodeling that plays a critical role in differentiation of precursors into multinucleated osteoclasts, and activation of osteoclasts leading to bone resorption. Dysregulation of RANK ligand (RANKL)-RANK-osteoprotegerin (OPG) signaling cascade induces the imbalance between bone formation and bone resorption, which leads to the changes in bone mass, increases osteoclast-mediated bone destruction, bone metastasis, and the progression of existing skeletal tumors. Recent evidences have shown that targeting the components of RANKL-RANK-OPG signaling pathway is a promising approach in the treatment of GCTB. This review study has focused on the association of RANKL-RANK-OPG pathway in the pathogenesis and progression of GCTB as well as discussed the possible therapeutic strategies by targeting this pathway.

Background One‐stage reconstruction of complex soft tissue defects of the extremities is a challenging problem. Repair of complex soft tissue defects requires adequate skin tissues to cover the large surface wound and special tissues for obliterating the dead space. The chimeric flap is one of the most popular approaches for reconstruction of complex soft tissue defects. However, the problems of donor‐site morbidity and inability to repair very large defects at one‐stage remain. The purpose of this study was to present our clinical experience using sequential chimeric perforator flaps for reconstruction of complex extremity defects with primary closure of the donor site. Methods From August 2013 to March 2017, 12 patients with complex soft tissue defects underwent extremity reconstruction using sequential chimeric perforator flaps, which were composed of a chimeric anterolateral thigh perforator (ALTP) flap and an additional free perforator flap. The skin paddles were placed side‐by‐side to cover the large surface soft tissue defects, and the muscle component was used to obliterate the dead space. Of these patients, one was injured by a crushing accident, while the other 11 patients were injured in traffic accidents. Results The size of the skin paddles ranged from 26 cm × 8 cm–10 cm × 6 cm to 30 cm × 8.5 cm–29 cm × 9 cm. The muscle paddle size ranged from 2 cm × 3 cm × 4 cm to 22 cm × 4 cm × 2 cm. All‐components of the sequential chimeric flaps survived in all‐patients. Vascular compromise was observed in one case. One case suffered minor wound‐edge necrosis and was treated conservatively. Primary closure of donor‐site was successfully achieved in all‐patients, and all‐donor‐site wounds healed uneventfully. The mean follow‐up time was 15.25 months. Most of the cases showed a satisfactory contour, and only two patients presented with mildly bulky appearance that treated with a debulking procedure. Conclusions The sequential chimeric perforator flap is an alternative procedure for reconstruct complex soft tissue defects of the extremities. This approach allows for flexible design, a larger cutaneous area, and low donor site morbidity.

The success of free vascularized fibular bone graft (FVFBG) has accelerated the osteo reconstruction which results from trauma, resection of a tumor or an infectious bone segment, or correction of congenital deformity. But the complication behind should not be overlooked. The failure could necessitate a second surgery, which prolong the rehabilitation period and produce further health cost. Worst, the patients may suffer a permanent impaired ankle function, or a sustained morpho-functional loss on reconstructive area which are hard to save. To provide an overview of the complication related to reconstruction by FVFBG, a narrative review is conducted to identify the complications including their types and rates, the contributing factors, the approaches to measure and the techniques to avoid. Methodologically, by quick research on Pubmed and abstract reading of reviews, we characterize five reconstructive areas where FVFBG were most frequently applied: extremities, mandible, spine, osteonecrosis of femoral head, and penile. Following, the complications on different reconstructive areas are retrieved, studied and presented in five (or more specifically, six) separate sections. By the way, meaningful difference between FVFBG and other bone flap was presented in a few words if necessary. Donor-site morbidities were studied and summarized as a whole. In these literatures, the evidences documented on limb and mandibular reconstruction have the fullest detail, followed by the spine and lastly the penile. In conclusion, FVFBG, though a mature technique, needs further deep and comprehensive study and maybe device-based assistance to achieve better reconstructive effect and minimize donor-site damage.

Our experience showed that the flow-through ALTP flap is reliable and suitable for reconstruction of complex defects of the extremities, as well as for various other clinical purposes.