A Safe Technique for Excising the Perpendicular Plate of the Ethmoid Bone in Patients with Crooked Nose: A Finite Element Analysis.

BACKGROUND: Correction of the crooked nose, especially the perpendicular plate of the ethmoid bone, has the potential to cause skull base injury. At present, the safe and effective method for perpendicular plate resection has not been clearly defined through biomechanics. METHOD: CT scan data of 48 patients with crooked nose and deviated nasal septum were divided into C-type, angular deformity-type, and S-type based on the morphology of the 3D model. Different types of finite element models of the nasal bony septum and skull base were established. The osteotomy depth, angle, and force mode of the PPE resection were simulated by assembling different working conditions for the models. The von Mises stress of the anterior cranial fossa was observed. RESULTS: When the osteotomy line length was 0.5 cm, the angle was at 30° to the Frankfurt plane, and 50 N·mm torque was applied, the von Mises stress of the skull base was minimal in the four models, showing 0.049 MPa (C-type), 0.082 MPa (S-type), 0.128 MPa (angular deformity-type), and 0.021 MPa (control model). The maximum von Mises stress values were found at the skull base when the osteotomy line was 1.5 cm, the angle was 50°, and the force was 10 N along the X-axis, showing 0.349 MPa (C-type), 0.698 MPa (S-type), 0.451 MPa (angular deformity-type), and 0.149 MPa (control model). CONCLUSION: The use of smaller resection angle with the Frankfurt plane, conservative resection depth, and torsion force can better reduce the stress value at the skull base and reduce the risk of basicranial fracture. It is a safe and effective technique for perpendicular plate resection of the ethmoid bone in the correction of crooked nose. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The SHH-GLI1 pathway is required in skin expansion and angiogenesis.

To investigate the role of GLI1 on skin proliferation and neovascularization during skin expansion in mice. We constructed GLI1-cre/R26-Tdtomato and GLI1-cre/R26-mtmg gene-tagged skin expansion mouse models. Using a two-photon in vivo imaging instrument to observe the changes in the number and distribution of GLI1(+) cells during the expansion process and to clarify the spatial relationship between GLI1(+) cells and blood vessels during the expansion process. In vitro proliferation assays were performed to further validate the effects of SHH (sonic hedgehog) and its downstream component GLI1 on cell proliferation viability. Finally, qRT-PCR was used to verify the changes in proliferation, angiogenesis-related factors, SHH signalling pathway-related factors, and the role of GLI1 cells in the process of skin expansion in mice. The number of GLI1(+) cells increased during dilation and were attached to the outer membrane of the vessel. The epidermis was thickened and the dermis thinned after the dilated skin was taken, while the epidermal thickening was suppressed and the dermis became thinner after the GLI1 cells were inhibited. The non-inhibited group showed a significant increase in PCNA positivity with prolonged dilation compared to the GANT61(GLI specificity inhibitor) inhibited group; CD31 immunofluorescence showed a significant increase in the number of dilated skin vessels and a significant decrease in the number of vessels after treatment with GANT61 inhibitor. In vitro proliferation results showed that SHH signalling activator significantly increased the proliferation viability of GLI1(+) hair follicle mesenchymal stem cells, while GNAT61 significantly inhibited the proliferation viability of GLI1(+) hair follicle mesenchymal stem cells. GLI1 is necessary for proliferation and neovascularization in expansion skin of mice through activation of the SHH signalling pathway.

Negative pressure wound therapy for flap closed-incisions after 3D-printed prosthesis implantation in patients with chronic osteomyelitis with soft tissue defects.

BACKGROUND: The flap closed-incisions healing after 3D-printed prosthesis implantation in Chronic Osteomyelitis with Soft Tissue Defects (COSTD) is critical. This study aimed to explore the safety and effectiveness of Negative Pressure Wound Therapy (NPWT) in promoting flap closed-incisions healing. METHODS: Retrospective analysis of clinical data was performed, including baseline, surgical and hospitalization information. The efficacy of NPWT was assessed by comparing the ASEPSIS scores, Visual Analogue Scale (VAS), Activity of Daily Living Scale (ADLS), and Lower Extremity Functional Scale (LEFS), as well as the major postoperative complications. RESULTS: The study included 20 patients, 13 received conventional dressing (Control group) and 7 received NPWT treatment (NPWT group). These two groups exhibited a notable disparity in the distribution of ASEPSIS scores, and the median scores were 24 in Control group and 9 in NPWT group (p = 0.001). Eight patients in the Control group experienced major incisional complications, including 7 cases of exudation, 3 cases of infection, 2 cases of non-healing, and 1 case of dehiscence, while none were observed in the NPWT group (p = 0.015). The VAS, ADLS, and LEFS scores were significantly improved in the NPWT group compared to the Control group (p = 0.003, 0.017, and 0.043, respectively). CONCLUSIONS: The study findings suggest that NPWT applied to the healing process of flap closed-incisions after 3D prosthesis implantation in patients with COSTD can reduce the occurrence of postoperative major complications and promote the recovery of lower limb function and daily activities, which should be recommended for clinical practice.

Modified fourth lumbar artery local perforator flap: an alternative for reconstruction of nonhealing lumbosacral spinal defects.

BACKGROUND: The reconstruction of nonhealing lumbosacral spinal defects remains a challenge, with limited options. The aim of this article was to review the authors' technique and experience with the modified fourth lumbar artery local perforator (MFLALP) flap for the coverage of nonhealing lumbosacral defects after spinal surgery. METHODS: Between August 2012 and May 2021, we reviewed all MFLALP flaps performed for lumbosacral spinal defects. Patient demographics, wound aetiologies, surgical characteristics, and outcomes were reviewed retrospectively. RESULTS: A total of 31 MFLALP flaps were performed on 24 patients during the research period. The median flap size was 152 cm2 (range, 84-441 cm2). All flaps survived successfully, although there were two cases of minor complications. One patient had a haematoma and required additional debridement and skin grafting at 1 week postoperatively. The other patient suffered wound dehiscence at the donor site at 2 weeks postoperatively and required reclosure. The follow-up time ranged from 6 months to 5 years. CONCLUSIONS: The MFLALP flap has the advantages of a reliable blood supply, sufficient tissue bulk and low complication rate. This technique is an alternative option for the reconstruction of nonhealing lumbosacral spinal defects.

Effect of Bone-Borne Trans -Sutural Distraction Osteogenesis Therapy on the Cranial Base of Children With Midfacial Hypoplasia Due to Cleft Lip and Palate.

Bone-borne trans -sutural distraction osteogenesis (TSDO) is widely used to treat midfacial hypoplasia in children with cleft lip and palate; however, its effects on the cranial base are still poorly understood. The authors aimed to study morphological changes in the cranial base after TSDO. Pre and postoperative computed tomography (CT) images of cleft lip and palate children with midfacial skeleton dysplasia who underwent TSDO were collected retrospectively, and their corresponding 3-dimensional models were measured. Results showed no significant change in the length of the anterior or posterior cranial fossa, but the length of the middle cranial fossa increased significantly. The anterior cranial base rotated upward with the sella turcica at the center, whereas the cranial base angle increased. The sphenoid bone exhibited morphological changes. Post-TSDO, the lateral plate of the pterygoid process increased in length. The angle of the 2 lateral plates of the pterygoid process, the greater wings of the sphenoid bone, and the smaller wings of the sphenoid bone decreased. Posterior inclination of the pterygoid process increased. Mean volume of the sphenoidal sinus increased postoperatively compared with the preoperative volume. Apparent changes in the cranial base after TSDO are primarily in the middle cranial fossa, manifesting as an increase in the sphenoid bone body length, expansion of the sphenoidal sinus volume, growth of the pterygoid process forward and downward, a decrease in the angle of both the greater and smaller wings of the sphenoid bone, and an increase in the posterior inclination of the pterygoid process.

The Effect of Trans-Sutural Distraction Osteogenesis on Nasal Bone, Nasal Septum, and Nasal Airway in the Treatment for Midfacial Hypoplasia in Growing Patients.

The purposes of this study were to analyze the effect of trans-sutural distraction osteogenesis (TSDO) on nasal bone, nasal septum, and nasal airway in the treatment of midfacial hypoplasia. A total of 29 growing patients with midfacial hypoplasia who underwent TSDO by a single surgeon were enrolled. The 3-dimensional measurement of nasal bone and nasal septum changes was performed using computed tomography (CT) images obtained preoperatively (T0) and postoperatively (T1). One patient was selected to establish 3-dimensional finite element models to simulate the characteristics of nasal airflow field before and after traction. After traction, the nasal bone moved forward significantly ( P <0.01). The septal deviation angle was lower than that before traction (14.43±4.70 versus 16.86 ±4.59 degrees) ( P <0.01). The length of the anterior and posterior margin of the vomer increased by 21.4% ( P <0.01) and 27.6% ( P <0.01), respectively, after TSDO. The length of the posterior margin of the perpendicular plate of ethmoid increased ( P <0.05). The length of the posterior inferior and the posterior superior margin of the nasal septum cartilage increased ( P <0.01) after traction. The cross-sectional area of nasal airway on the deviated side of nasal septum increased by 23.0% after traction ( P <0.05). The analysis of nasal airflow field showed that the pressure and velocity of nasal airflow and the nasal resistance decreased. In conclusion, TSDO can promote the growth of the midface, especially nasal septum, and increase the nasal space. Furthermore, TSDO is conductive to improve nasal septum deviation and decrease nasal airway resistance.

The Morphological and Functional Effects of the Endoscope-Assisted One-Stage Approach for Crooked Nose.

BACKGROUND: A crooked nose is an external nose deformity predominantly caused by congenital aplasia or acquired secondary to trauma or surgery, often accompanied by a deviated nasal septum. Patients with crooked nose have dual needs to improve both esthetic and functional problems. METHODS: The clinical and photographic information of 48 patients diagnosed with a crooked nose and nasal septum deviation treated from January 2018 to January 2022 was acquired. The morphology and functional effects were investigated by evaluating the general condition of the operation, measuring the esthetic indexes of the nose, and subjectively scoring. RESULTS: For both morphology and function, endoscopy-assisted one-stage correction showed positive results in this study. The external nose deviation distance postoperatively measured 1.28 (0.85, 1.97) mm, which significantly decreased from the preoperative value of 3.96 (3.31, 5.29) mm. The scores of doctors and irrelevant medical students on nose morphology increased significantly from 4.75±1.88 and 3.84±0.76 to 6.48±1.21 and 7.21±0.67, respectively. The rhinoplasty outcome evaluation score and the "nasal obstruction symptom evaluation "score of patients were both significantly improved ( t = -7.508 and t =6.310, respectively, P < 0.001). CONCLUSION: Endoscope-assisted one-stage correction of the crooked nose can restore nasal morphology, improve the symptoms of nasal obstruction, and achieve patient satisfaction. It is a minimally invasive, safe, effective, and fast recovery approach for patients who need to solve both esthetic and functional problems.

Autologous Shuffling Lipo-Aspirated Fat Combined Mechanical Stretch in Revision Rhinoplasty for Severe Contractures in Asian Patients.

BACKGROUND: A severely contracted nose is a common occurrence. Intraoperative expansion is not sufficient to soften the severely constricted nasal envelope, which poses challenges in revision rhinoplasty. In recent years, adjuvant therapies, including nasal fat grafting and cell component injection, are applied before revision rhinoplasty to soften the nasal envelope. Herein, autologous shuffling lipo-aspirated fat and manual mechanical stretch were combined as adjuvant therapy before revision rhinoplasty. METHODS: A total of 24 patients with severe nasal contracture were included in this study. Of these, 8 received autologous shuffling lipo-aspirated fat and manual mechanical stretch before revision rhinoplasty (comprehensive therapy), 8 underwent mechanical stretch and revision rhinoplasty, and 8 patients underwent only revision rhinoplasty. The objective and subjective outcome assessment was processed in the follow-up period of 6 months. Nasal length, nasal tip projection, nasofrontal angle, and nasolabial angle were measured, and potential complications were assessed. RESULTS: All 24 patients underwent a successful revision rhinoplasty. In the comprehensive therapy group, no patient had postoperative wound infection and defect of the nasal column mucous. The comprehensive treatment group had the most significant improvement in nasal length and nasal tip projection, and the nasolabial angle was the closest to 90°, which indicated the most effective nasal revision and aesthetic contour. CONCLUSIONS: The adjuvant therapy combines autologous shuffling lipo-aspirated fat and manual mechanical stretch before revision rhinoplasty could effectively improve the surgical outcome and decrease the postoperative complications regarding severe nasal contractures. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Viability and Stability of Various-Sized Free Diced Cartilage in an Experimental Study.

BACKGROUND: Historically, research of diced cartilage for rhinoplasty has mainly explored the efficacy of wrapped materials, with few studies dedicated to various sizes of diced cartilage. OBJECTIVES: The authors of this study sought to evaluate the viability and stability of various-sized free diced cartilage. METHODS: The remaining costal cartilage was harvested during rhinoplasties and implanted into subcutaneous pockets on the backs of nude mice: shaved cartilage (group A, n = 8), diced cartilage with a diameter <0.5 mm (group B, n = 8), 0.5 to 1.0 mm (group C, n = 8), and 1.0 to 1.5 mm (group D, n = 8). After 12 weeks, weight and volume retention rates, histopathological examinations, and biomechanical properties were evaluated. RESULTS: Cartilage grafts in groups A and B showed an obvious loss of contour and severe dispersion. The weight and volume of cartilage graft in group A were significantly decreased (all P < 0.05). Although there was no significant difference, group D (122.8 ± 15.4%) achieved the highest weight retention rate compared with groups B and C (114.6 ± 7.1% and 114.3 ± 10.1%, respectively). Group A showed the most apparent chondrocyte nucleus loss with the least peripheral proliferation, and group D showed the best regeneration potential (all P < 0.05). Group C achieved less chondrocyte nucleus loss than group B (P < 0.05). The compressive elastic modulus increased with the diameter of diced cartilage (all P < 0.05). CONCLUSIONS: Diced cartilage with a diameter of 1.0 to 1.5 mm may have the highest viability and stability, followed by those of 0.5 to 1.0 mm and <0.5 mm.

Application of VSD technique in adults with chronic osteomyelitis of the extremities combined with soft tissue defects.

To investigate the clinical application of vacuum sealing drainage (VSD) in chronic osteomyelitis of the extremities combined with soft tissue defects in adults. This study retrospectively included 32 adult patients with clearly diagnosed chronic osteomyelitis of the extremities combined with local soft tissue defects, and the trauma was covered by VSD after debridement, osteotomy, and vancomycin-laden bone cement filling of the occupancy, and the trauma was covered by selecting a suitable flap transfer repair according to the site and extent of the soft tissue defect after the trauma condition was suitable, and the secondary trauma was taken from the abdominal full-thickness skin free skin slice graft, according to whether the skin graft area was performed. The skin flap hematoma and infection rate, as well as the skin flap survival rate and implant fixation time were compared and analysed between the two groups. The primary outcome is the implant fixation time, and the secondary outcome is the skin fragment survival rate. In 32 patients, VSD was performed on the bone cement surface to cover the trauma, and 33.2 to 39.8 kPa continuous vacuum sealing drainage was set. The average VSD time duration before soft tissue coverage was 47.87 ± 23.14 days, and the average number of VSD use was 7.18 ± 3.23. The use of VSD before soft tissue coverage did not cause complications such as negative pressure could not be maintained, vacuum sealing drainage was not smooth, skin blistering, trauma. Among the 32 patients, 12 cases of soft tissue coverage were followed by trauma free skin grafting with packing + VSD, and 20 cases were fixed with packing alone, and the duration of continuous packing and fixation of free skin pieces in the VSD group was significantly less than that in the control group (P = .006). The survival rate was significantly higher than that of the control group (P = .019). VSD in adult patients with chronic osteomyelitis of the extremities combined with soft tissue defects can effectively improve the trauma condition, provide the possibility of second-stage soft tissue coverage, and significantly shorten the preparation time for soft tissue coverage. In addition, when soft tissue coverage trauma is performed, VSD combined with skin graft packing technique can significantly improve the survival rate of skin pieces, shorten the time of skin graft fixation.

Regional flap: A reliable coverage for post-radiation ulcer.

Ulcer in radiation-damaged tissue is a dilemma with limited treatment strategies. The study aimed to evaluate the safety and efficacy of regional flaps for patients with post-radiation ulcers through a 10-year experience. A retrospective study of consecutive patients with post-radiation ulcers at a single institute from 2012 to 2022 was conducted. Reconstruction included complete excision of irradiated tissue and coverage with well-vascularised tissue, including local flaps, regional flaps and free flaps. Study outcomes included complications, reoperation rates, overall flap success and recurrence rates. Thirteen patients (six males and seven females; mean age, 56.85 ± 13.87 years) with a mean 10-month history of post-radiation ulcers were enrolled. Ulcers are predominantly located in the chest (n = 3, 23.1%), head (n = 2, 15.4%) and neck (n = 2, 15.4%), with a mean size of 33.1 cm2 (range from 1 cm2 to 120 cm2 ). Eleven patients underwent reconstruction with 15 regional flaps and three local flaps, one patient received a free anterolateral thigh fasciocutaneous flap and one patient underwent amputation. Among these 15 regional flaps, one (6.7%) had wound dehiscence and four (26.7%) had localised necrosis requiring reoperation. In addition, one patient with a non-healing sinus tract underwent reoperation. The overall success rate of the regional flap was 100% and no recurrence was observed with a mean follow-up of 23.3 months. Regional flaps seem a safe and effective reconstructive method for post-radiation ulcers.

Proteomic Difference Analysis of Whole Blood and Bloodstains.

OBJECTIVES: To study the changes of protein levels in peripheral blood after it dried. METHODS: The proteins from whole blood and bloodstains were detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and normalized by the label-free quantification (LFQ) method. The differential proteins were analyzed by using R 4.2.1 software, limma and edgeR package. The analysis of biological function, signaling pathway and subcellular localization for the differential proteins was then performed. RESULTS: A total of 623 and 596 proteins were detected in whole blood and bloodstains, respectively, of which 31 were statistically significant in the quantitative results, including 10 up-regulated and 21 down-regulated proteins in bloodstains. CONCLUSIONS: The protein abundances in whole blood and bloodstains are highly correlated, and the variation of protein abundances may be related to the changes of endogenous and structural proteins in cells. The application of proteomics technology can assist the screening and identification of protein biomarkers, thereby introducing new biomarkers for forensic research.

Suture Cells in a Mechanical Stretching Niche: Critical Contributors to Trans-sutural Distraction Osteogenesis.

Trans-sutural distraction osteogenesis has been proposed as an alternative technique of craniofacial remodelling surgery for craniosynostosis correction. Many studies have defined the contribution of a series of biological events to distraction osteogenesis, such as changes in gene expression, changes in suture cell behaviour and changes in suture collagen fibre characteristics. However, few studies have elucidated the systematic molecular and cellular mechanisms of trans-sutural distraction osteogenesis, and no study has highlighted the contribution of cell-cell or cell-matrix interactions with respect to the whole expansion process to date. Therefore, it is difficult to translate largely primary mechanistic insights into clinical applications and optimize the clinical outcome of trans-sutural distraction osteogenesis. In this review, we carefully summarize in detail the literature related to the effects of mechanical stretching on osteoblasts, endothelial cells, fibroblasts, immune cells (macrophages and T cells), mesenchymal stem cells and collagen fibres in sutures during the distraction osteogenesis process. We also briefly review the contribution of cell-cell or cell-matrix interactions to bone regeneration at the osteogenic suture front from a comprehensive viewpoint.

Influence of Bone-Borne Trans-Sutural Distraction Osteogenesis Therapy on the Hard Palate of Growing Children With Cleft Lip and Palate.

ABSTRACT: The efficacy of trans-sutural distraction osteogenesis therapy (TSDO) in treating midfacial hypoplasia in children with cleft lip and palate has been confirmed. However, few studies have reported that changes occur in the palate after TSDO treatment. To study the effect of TSDO on palatal morphology and its relative position in the craniofacial region, we retrospectively collected and measured the computed tomography images of 29 growing children with cleft lip and palate and midfacial hypoplasia, before and after TSDO. The results showed that the length and height of the palate did not change significantly, but the width and arch length increased, and the anterior area was more pronounced than the posterior area, with the median palatine suture still centered without obvious deviation. This suggests lateral palate growth after distraction, most likely around the median palatine suture. The distance from the palate to the cranial base also increased after distraction, and the anterior nasal spine moved forward, whereas the palate rotated by an average of 10.04° downward from the center of the anterior nasal spine. The increasing distance between the palate and cranial base may result from the growth of the nasal bone or the skull base. The oropharyngeal airway volume was also increased by an average of 2256.36 mm3, which may be beneficial to children's ventilatory function. In conclusion, TSDO therapy has influence on patients' palatal morphology and position, which should be considered before surgery.

Four cases of abdominal expander implantation in adult chronic osteomyelitis of lower extremity with soft tissue defect and literature review.

In this study, we intend to explore the clinical efficacy of abdominal expander implantation combined with flap technique in adult chronic osteomyelitis of lower limb with soft tissue defects, and to provide the basis for the promotion of the technique in clinical practice. Four patients diagnosed with chronic osteomyelitis of lower extremity with soft tissue defect were enrolled in this prospective study. Evaluation indicators included state of flap survival, state of abdominal incision, surrounding of abdominal wound scar, satisfaction of the patient, state of flap survival half a year after surgery, whether the 3D prosthesis is successfully implanted and limb movement. Four patients had complete flap survival, two of whom had a small amount of skin graft survival disorder in the vascular pedicle area, which improved after 1 month of dressing change. The expander had an average expansion time of 31.5 days, an average water injection of 525 mL, and an average skin volume taken of 159 cm2 . No incision exudation, incision dehiscence, subcutaneous exudate and other complications occurred. The mean Vancouver Scar Scale score at 3 months after surgery was 3.5 (range from 3 to 6) points. Four patients showed good flap survival at six-month follow-up. 3D printed prosthesis were all successfully implanted. The treatment of adult chronic osteomyelitis of lower extremities with lower abdominal implantable expander combined with flap technique can effectively increase the skin harvesting area, reduce the suture tension of abdominal skin harvesting area and the scar hyperplasia of abdominal skin harvesting area.

Island sternocleidomastoid myocutaneous flap for posterior pharyngeal wall defect repair after anterior cervical spine surgery.

Injuries and tumours of the cervical spine represent therapeutic challenges to the treating surgeon due to the complex anatomical relationships and biomechanical features. The anterior cervical midline (ACM) and anterior cervical retropharyngeal (ACR) approaches are effective and safe surgical approaches for certain cervical spine lesions, such as cervical spine neoplasms, atlantoaxial subluxation, and certain odontoid fractures. Posterior pharyngeal wall defects (PPWDs) is one of the most frequently encountered surgical morbidities after anterior cervical spine surgery (ACSS). However, limited information has been published concerning effective approaches for PPWD reconstruction after ACSS. The manuscript aimed to describe a novel application of the island sternocleidomastoid myocutaneous flap (ISMF) in the management of PPWDs after ACSS, including surgery with the ACM approach and ACR approach. From April 2015 to November 2019, the clinical data of three patients with PPWDs repaired using the ISMF in Peking university third hospital were retrospectively analysed. The observational indexes are as follows: postoperative survival of the flap, wound healing 2 weeks after surgery, eating and pronunciation function 2 months after surgery. The above indexes of these three cases recovered well. Three patients did not have any persistent PPWD after repair with the ISMF and did not require any further surgical procedures related to the cervical spine.

Clinical significance of the secondary pedicle amputation of the repair of distal defects with pedicled axial flap.

We aimed to explore the clinical significance of the secondary pedicle amputation of the repair of distal defects with pedicled axial flap. Five patients who underwent pedicled axial flap transfer to repair a large area of skin and soft tissue defects in our hospital were included in this retrospective study. Detailed information including general data and clinical data, such as preoperative complication, type of primary wound, the distance between the primary wound and the donor site (cm), postoperative complications, and types of axial flap were collected. The patients had good joint movement at 6 months after pedicle amputation. At 48 hours after transplantation, except for the last patient (NO.5), there were no obvious complications such as blood supply disorder, infection, and incision dehiscence of the patients, and the flaps survived well. Just after pedicle amputation, 3 and 6 months after pedicle amputation, the flaps survived well with good local morphology. Forty-eight hours after operation, part of the distal flap in the last patient (NO.5) was necrotic. After 6 months of pedicle amputation, part of the flap was transferred to the distal wound again. At 6 months after pedicle amputation, these patients could accept local scars even though the scar of the last patient was obvious. The secondary pedicle amputation of the repair of distal defects with axial flap could avoid the compression of the vascular pedicle in the subcutaneous tunnel between the donor site and the primary wound, which may ensure the bold supply and increase the survival rate of the flap.

Clinical study on orthopaedic treatment of chronic osteomyelitis with soft tissue defect in adults.

To investigate the clinical application value of different flap transfer and repair techniques in adult patients with chronic osteomyelitis of limbs complicated with soft tissue defects. According to the characteristics and defects of 21 cases, different plastic surgery was applied, including debridement, negative pressure device, and tissue flap to cover wound. Among 21 cases of chronic osteomyelitis complicated with local soft tissue defect, 15 patients were repaired with sural neurotrophic musculocutaneous flap transfer, 2 patients were repaired with medial plantar skin flap transfer, 2 patients were repaired with ilioinguinal skin flap transfer, 1 patient was repaired with z-forming wound, and 1 patient was repaired with soleus muscle flap combined with full-thickness skin graft. All the 21 patients underwent bone cement implantation after dead bone osteotomy. Among them, 19 patients underwent bone cement replacement with 3D prosthesis within 6 months to 1 year after surgery, and 2 patients carried bone cement for a long time. Early intervention, thorough debridement, removal of necrotic or infection, and then selecting the appropriate wound skin flap coverage are important means of guarantee slow osteomyelitis wound healing and for providing a possible way to permanent prosthesis implantation subsequently.

Polarized M2 macrophages induced by mechanical stretching modulate bone regeneration of the craniofacial suture for midfacial hypoplasia treatment.

The underlying mechanism of the trans-sutural distraction osteogenesis (TSDO) technique as an effective treatment that improves the symptoms of midfacial hypoplasia syndromes is not clearly understood. Increasing findings in the orthopedics field indicate that macrophages are mechanically sensitive and their phenotypes can respond to mechanical cues. However, how macrophages respond to mechanical stretching and consequently influence osteoblast differentiation of suture-derived stem cells (SuSCs) remains unclear, particularly during the TSDO process. In the present study, we established a TSDO rat model to determine whether and how macrophages were polarized in response to stretching and consequently affected bone regeneration of the suture frontal edge. Notably, after performing immunofluorescence, RNA-sequencing, and micro-computed tomography, it was demonstrated that macrophages are first recruited by various chemokines factors and polarized to the M2 phenotype upon optimal stretching. The latter in turn regulates SuSC activity and facilitates bone regeneration in sutures. Moreover, when the activated M2 macrophages were suppressed by pharmacological manipulation, new bone microarchitecture could rarely be detected under mechanical stretching and the expansion of the sutures was clear. Additionally, macrophages achieved M2 polarization in response to the optimal mechanical stretching (10%, 0.5 Hz) and strongly facilitated SuSC osteogenic differentiation and human umbilical vein endothelial cell angiogenesis using an indirect co-culture system in vitro. Collectively, this study revealed the mechanical stimulation-immune response-bone regeneration axis and clarified at least in part how sutures achieve bone regeneration in response to mechanical force.

Sutural fibroblasts exhibit the function of vascular endothelial cells upon mechanical strain.

Midfacial hypoplasia is a type of facial dysplasia. The technique of trans-sutural distraction osteogenesis promotes midface growth so as to ameliorate this symptom. In the process of distraction osteogenesis, the fiber matrix in the suture acts as a mechanical sensor. Compared with osteogenesis, the formation of collagen fibers by fibroblasts is significant in the early stage of sutural distraction. However the transformation of fibroblasts during sutural bone formation induced by tensile force is poorly characterized. Here, we used single-cell RNA sequencing to define the cell classification of the zygomatic maxillary suture and the changes of cell clusters in the suture before and after seven-day distraction. We identified twenty-nine cell subsets spanning monocyte/macrophages, neutrophils, red blood cells, B cells and fibroblasts. Compared with the control group, Monocle analysis revealed the emergence of a unique fibroblast subset (Cdh5+, Col4a1+, Fat1-, and Acta2-) (cluster 27) that expressed vascular endothelial cell genes within the distracted zygomatic maxillary suture. We constructed the differentiation trajectories of the fibroblast population (cluster 23, 27) in the suture before and after distraction. In addition, we clarified that a subset of fibroblasts (cluster 27) lost expression of Fat1, an upregulator of the Hippo pathway, and upregulated Cyr61, a downstream gene of the Hippo pathway, during the distraction process. Further enrichment analysis suggests that cells of the new subset (cluster 27) are undergoing conversion of their identity into a vascular endothelial cell-like state in response to mechanical stimulation, associated with upregulation of angiogenesis genes along the single-cell trajectory. Further immunofluorescence staining confirmed this phenomenon. A combined general transcriptome RNA sequencing data analysis demonstrated that the fibroblasts expressed a number of extracellular matrix-related genes under mechanical strain. These data together provide a new view of the role of fibroblasts in tension-induced sutural angiogenesis via interaction with the Hippo pathway.