Promotion effect of TGF-β-Zfp423-ApoD pathway on lip sensory recovery after nerve sacrifice caused by nerve collateral compensation / 国际口腔科学杂志·英文版

Resection of oral and maxillofacial tumors is often accompanied by the inferior alveolar nerve neurectomy, resulting in abnormal sensation in lower lip. It is generally believed that spontaneous sensory recovery in this nerve injury is difficult. However, during our follow-up, patients with inferior alveolar nerve sacrifice showed different degrees of lower lip sensory recovery. In this study, a prospective cohort study was conducted to demonstrate this phenomenon and analyze the factors influencing sensory recovery. A mental nerve transection model of Thy1-YFP mice and tissue clearing technique were used to explore possible mechanisms in this process. Gene silencing and overexpression experiments were then conducted to detect the changes in cell morphology and molecular markers. In our follow-up, 75% of patients with unilateral inferior alveolar nerve neurectomy had complete sensory recovery of the lower lip 12 months postoperatively. Patients with younger age, malignant tumors, and preservation of ipsilateral buccal and lingual nerves had a shorter recovery time. The buccal nerve collateral sprouting compensation was observed in the lower lip tissue of Thy1-YFP mice. ApoD was demonstrated to be involved in axon growth and peripheral nerve sensory recovery in the animal model. TGF-β inhibited the expression of STAT3 and the transcription of ApoD in Schwann cells through Zfp423. Overall, after sacrificing the inferior alveolar nerve, the collateral compensation of the ipsilateral buccal nerve could innervate the sensation. And this process was regulated by TGF-β-Zfp423-ApoD pathway.

Masquelet technique combined with tissue flap transfer in treatment of early and middle stage infected composite bone and soft tissue defects after internal fixation of tibial fractures / 中华显微外科杂志

Objective:To explore the clinical efficacy of Masquelet technique combined with tissue flap transfer in the treatment of infectious composite bone and soft tissue defects in the early and middle stages after internal fixation for tibial fractures.Methods:From October 2017 to November 2020, 12 patients (13 tibial fractures) with infectious bone and soft tissue defects in the early and middle stages after internal fixation were treated in the Department of Orthopaedics, 988th Hospital of the Joint Logistics Support Force of CPLA by two-phased surgery with retaining internal fixation. Phase I procedures were thoroughly removal of the infected lesions and failed screws, preserving internal implants as many as possible, implantation of absorbable calcium sulphate and an antibiotics blended string of beads into the distal and proximal medullary cavity of the fractured bones, filling the bone defect and wrapping the internal implants with antibiotics loaded bone cement. The size of defects was 3.5 cm × 5.0 cm-7.5 cm × 14.5 cm, and the flaps for wound coverage sized 4.0 cm × 5.5 cm-8.0 cm × 15.0 cm. As for the repair of donor site, 8 limbs were sutured directly, 5 limbs could not be closed completely, and the remaining wounds were covered by skin grafting after suture. Based on well control of infection and stable clinical signs, fillings of bone cement were then removed in Phase II surgery, or 6-9 weeks after primary surgery. Autologous cancellous bone pieces or composite allogeneic bone were fully implanted around the induction membrane formed by Masquelet technique, and auxiliary steel plates were implanted for internal fixation of unstable fractures. After discharge, the patients visited the outpatient clinic regularly, and combined with Wechat follow-up. The texture, colour and bone healing were observed. At the last follow-up, the function of the affected limbs were assessed according to Johner-Wruhs evaluation standard.Results:After Phase I surgery, 13 flaps survived smoothly without vascular compromise. The wounds healed in Phase I. Two patients (2 sides) had recurrent infections. Re-debridement was performed and external fixation was applied after removal of internal fixation. After Phase II surgery, all patients were included in 12-26 months of follow-up, with an average of 18 months. Thirteen lower leg fractures healed well, and the time of bone healing was 16-25 (average 19.5) weeks. The Johner Wruhs criteria was used in evaluation of the function of affected limbs, and it was found that 6 patients were in excellent, 5 in good and 2 in fair.Conclusion:It is feasible while preserving the internal implants, to use membrane induction technique (Masquelet technique) combined with flap transfer, together with the absorbable calcium sulphate antibiotic sustained-release beads as a carrier in the phased treatment of infectious bone defects and bone exposure in the early and middle stages after the surgery of tibial internal fixation. It also gives a higher rate of excellence in surgical outcome. This study explores a treatment procedure for traumatic bone infection combined with composite soft tissue defects.