Search Results (572)

Reconstruction of craniomaxillofacial (CMF) bony defects requires individualized strategies based on defect characteristics and graft bed biology, with traditional approaches relying on autogenous non-vascularized bone grafts or vascularized free flaps that, while reliable, are associated with donor-site morbidity and operative complexity. Biologically driven reconstructive strategies, including tissue engineering, cellular bone matrix allografts (CBMs), and growth factor adjuncts, have emerged as alternatives or complements to autograft-based reconstruction. This review introduces and details these new innovations with emphasis on the current literature, thus empowering surgeons to enhance their clinical armamentarium. Full article

Objectives: To clarify the characteristics of Basosquamous cell carcinoma (BSC), this study compares demographic, clinical, therapeutic, histological, and outcome findings of BSCs with those of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Methods: The authors classified various definitions of BSC into three groups: the broadest, modest, and narrowest definitions. This study adopted the narrowest definition (both BCC and SCC features with transition zones in between) due to its wide use, its adoption by the World Health Organization, and the least heterogeneous definition. From 2009 to 2018, 20 consecutive cases of BSC presented in a single institution, along with 130 cases of BCC and 81 cases of SCC. Results: The statistically different parameters of BSC compared to BCC or SCC were age (SCC > BSC, BCC), duration (BSC, BCC > SCC), unclear border (BSC > BCC, SCC), higher NCCN classification (BSC, SCC > BCC), safety margin (SCC > BSC > BCC), operation time (BSC, SCC > BCC), reconstruction (less primary closure in BSC than BCC), microscopic size (BSC, SCC > BCC), perineural invasion (BSC > BCC), free lateral margin (BSC, SCC > BCC), and follow-up period (BSC > BCC, SCC). Regarding outcome, one distant metastasis (6.3%) in BSCs, no aggressive consequences in BCCs, and four local recurrences (11.1%), two lymph node metastases (5.6%), and one distant metastasis (2.7%) in SCCs were observed. Conclusions: In this Asian cohort, BSC has a trend toward higher rates of overall adverse outcomes compared to BCC, although this difference did not reach definitive statistical significance, unlike the findings reported in Caucasian populations. Early detection and appropriate treatment at the individual patient level are warranted to minimize rare but clinically relevant adverse events and reproduce favorable outcomes at the population level. Wide local excision followed by local flaps could be a successful surgical option with an adequate safety margin and double histopathologic intraoperative and postoperative check-up. Full article

Reconstruction of the ear and temporal region presents unique challenges due to the complex anatomy of the lateral skull base and the need to restore both structural integrity and auditory function. Historically managed as separate entities, auricular reconstruction and hearing rehabilitation are increasingly approached in an integrated manner, supported by advances in microsurgical techniques and implantable hearing technologies. This narrative review synthesizes contemporary evidence on microsurgical reconstruction of the ear and temporal region in conjunction with hearing rehabilitation, analyzing a wide range of existing surgical techniques in an integrative manner. Reconstructive techniques discussed include local and regional flaps, free tissue transfer, auricular framework reconstruction using autologous cartilage or alloplastic materials, external auditory canal reconstruction, and subtotal petrosectomy. Hearing rehabilitation options reviewed encompass bone-anchored hearing systems, active and passive transcutaneous devices, middle ear implants, and cochlear implantation. Simultaneous reconstruction and implantation may reduce surgical burden and enable earlier hearing restoration in carefully selected patients, while staged approaches remain advantageous in complex or high-risk scenarios, particularly in the presence of chronic infection or extensive temporal bone surgery. Multidisciplinary collaboration, meticulous preoperative planning, and long-term follow-up are essential to optimize outcomes. Full article

Background: Complex head and neck defects often require simultaneous reconstruction of multiple tissue types. The thoracodorsal artery-based chimeric flap offers the potential to address these requirements through a single vascular pedicle. Methods: A retrospective review of patients who underwent head and neck reconstruction using thoracodorsal chimeric flaps at two institutions (2009–2026) was performed. Flap configurations incorporated combinations of the thoracodorsal artery perforator skin paddle, latissimus dorsi muscle, and serratus anterior muscle. Results: Nineteen patients (mean age 63.2 years) were included. Primary sites were the hypopharynx (42.1%) and oral cavity (36.8%). Flap survival was 100%. Reconstruction-related complications occurred in 47.4% of patients, most commonly pharyngocutaneous fistula or leakage (31.6%), all managed conservatively or with secondary closure. Among survivors, 100% achieved tracheostomy decannulation and oral intake. Conclusions: The thoracodorsal chimeric flap may be a useful option for complex head and neck reconstruction requiring multiple tissue components through a single pedicle. However, the complication rate highlights the challenges inherent in this high-risk population, warranting further prospective validation. Full article

Background/Objectives: Recent meta-analyses have established that factors such as sarcopenia, male sex, and low serum albumin significantly correlate with increased postoperative complications in head and neck surgery, with routine neck computed tomography (CT) at the third cervical vertebra (C3) serving as a practical tool for muscle mass assessment. This study aimed to confirm the prognostic value of C3-based sarcopenia and specific clinical comorbidities in predicting early postoperative complications in patients with oral squamous cell carcinoma (OSCC). Methods: A retrospective cohort study was conducted on 167 patients undergoing primary surgery for OSCC. Sarcopenia was assessed using the C3-vertebra skeletal muscle index (SMI) derived from routine preoperative neck CT scans. Clinical and surgical variables, including preoperative serum albumin levels, comorbidities, and flap reconstruction types, were evaluated. A priori multivariate logistic regression models were utilized to identify independent predictors of surgical site and pulmonary and total complications (Clavien–Dindo classification) within 30 days. Results: The overall complication rate was 51%. Multivariate analysis revealed that sarcopenia (aOR: 3.26; 95% CI: 1.11–9.56), male sex (aOR: 3.48; 95% CI: 1.11–10.85), coronary artery disease (CAD) (aOR: 4.30; 95% CI: 1.21–15.36), and free-flap reconstruction (aOR: 15.06; 95% CI: 2.47–92.01) were robust independent predictors of total complications. Male sex (aOR: 4.17; 95% CI: 1.51–11.58) and preoperative hypoalbuminemia (<3.5 g/dL) (aOR: 3.43; 95% CI: 1.20–9.82) were independent predictors of surgical site complications, while regional flap reconstruction was independently associated with pulmonary complications (aOR: 5.97; 95% CI: 1.38–25.97). Conclusions: Sarcopenia, male sex, CAD, and flap reconstruction type are strong independent predictors of postoperative morbidity in OSCC. These findings advocate for “opportunistic screening” of muscle mass via routine preoperative neck CT, alongside rigorous cardiovascular profiling, to identify high-risk phenotypes for targeted perioperative optimization. Full article

The role of soft tissue reconstruction in infection control of knee periprosthetic joint infection (PJI) treated with a two-stage exchange strategy remains controversial. This retrospective observational study analysed consecutive patients with chronic knee PJI managed with a two-stage protocol between 2010 and 2023, comparing outcomes between cases requiring flap-based soft tissue reconstruction and those achieving primary closure. A total of 118 patients with a minimum follow-up of 24 months were included. Forty patients (33.9%) required soft tissue reconstruction (STR), including 25 pedicled medial gastrocnemius flaps and 15 anterolateral thigh (ALT) microsurgical free flaps. Patients requiring STR showed greater baseline complexity, with a higher number of previous surgical procedures (3.03 vs. 2.08; p = 0.0057) and a higher prevalence of diabetes mellitus and sinus tracts. Despite this, infection control was superior compared with non-reconstructed cases (100% vs. 88.5%; p = 0.029). Within the STR group, both pedicled and microsurgical techniques achieved complete infection eradication; however, ALT flaps were associated with higher complication rates (46.7%), with partial flap necrosis being the most frequent event. The use of microsurgical reconstruction increased progressively over time, reflecting growing reconstructive complexity. Formal soft tissue reconstruction does not compromise and may facilitate infection control within a multidisciplinary pathway. Full article

The aerodynamics of avian flight provides critical inspiration for the design of bioinspired aerial vehicles, yet the quantitative characterization of free-flight wing kinematics remains challenging. This study employs a neural-network-based motion tracking approach (DeepLabCut) to analyze wingbeat kinematics in free-flying birds from video data. We automatically digitize key wing points and reconstruct three-dimensional trajectories to quantify asymmetric flapping patterns. Our analysis reveals that while wing oscillations approximate sinusoidal motion, they exhibit statistically significant velocity differences between upstroke and downstroke phases, confirming the stroke asymmetry of avian flapping. Furthermore, using video of a flying frigatebird (Fregata ariel), we quantify the changes in the effective wing area throughout the wingbeat cycle, showing a ~19% variation that significantly impacts lift generation efficiency. These findings provide quantitative benchmarks for avian-inspired wing design and offer insights for optimizing flapping kinematics in bioinspired aerial systems, particularly for enhancing takeoff and landing capabilities in micro air vehicles. Full article

Background/Objectives: Virtual surgical planning (VSP) and CAD/CAM technologies have revolutionized complex maxillofacial reconstruction. While high-resolution imaging is critical for these workflows, the specific clinical impact of photon-counting computed tomography (PCCT) remains to be fully established. This prospective pilot study evaluates the feasibility and clinical utility of integrating PCCT into the preoperative planning and surgical workflow of complex maxillofacial reconstructive cases. Methods: This feasibility study included ten patients requiring complex maxillofacial reconstruction with microvascular free flaps. All underwent preoperative imaging with photon-counting CT. Primary endpoints included clinical assessment of osseous invasion, reliability of donor-site vascular mapping from a single acquisition, and compatibility of PCCT datasets with VSP/CAD-CAM platforms. Secondary endpoints included resection margin status, flap survival, and short-term oncologic outcomes. Results: PCCT provided high-resolution visualization of cortical and medullary bone, enabling detailed assessment of tumor-related osseous involvement. In selected cases, findings supported refinement of resection planning when prior imaging had been inconclusive. Spectral reconstructions reduced metal artifacts and facilitated precise segmentation for multi-segment osteotomies. Donor-site vascular anatomy was successfully evaluated within the same scan, supporting operative planning without additional imaging. PCCT datasets were fully compatible with the virtual surgical planning (VSP) software used in this study (CMX Portal, version 2.6.1158, Medartis AG, Basel, Switzerland; or ProPlan CMF, version 5.7.8.025, Materialise NV, Leuven, Belgium) in all cases (100%). Reconstruction was completed successfully in all patients, with 100% flap survival and R0 margins in all malignant cases. No technical failures occurred during imaging transfer or CAD/CAM fabrication. Conclusions: The integration of PCCT into the surgical workflow proved technically feasible and clinically impactful. This pilot data supports its potential to enhance surgical precision and preoperative planning in complex jaw reconstruction. Full article

Ornithopters generate lift and thrust through periodic flapping-wing motion. While control-based optimization has been widely studied to improve the flight efficiency of ornithopters, passive mechanical tuning remains underexplored. This study investigates whether integrating a lightweight torsional spring can passively tune a flapping-wing system toward resonance to reduce input power and enhance aerodynamic performance. We evaluated springs of different stiffness on a 3D-printed, motor-driven flapping rig, recording input voltage and current as well as flapping frequency and thrust. Wing kinematics were analyzed using high-speed video, and free-oscillation tests identified a resonant period of ~0.14 s (~7.1 Hz). Experimental results show that an optimally tuned spring-assisted system achieves up to a threefold improvement in thrust efficiency and up to a twofold improvement in kinematic efficiency, compared to the no-spring baseline. Indoor flight tests using a commercial ornithopter (MetaFly) confirmed the improvement, showing a 12.8% increase in average endurance. The spring-assisted configuration also produced smoother stroke reversals, consistent with reduced energy losses. These results demonstrate that a low-complexity, lightweight torsional spring tuned near resonance can provide an effective passive means to enhance both energy efficiency and aerodynamic output in flapping-wing UAVs, serving as a practical, low-cost complement to control-based optimization methods. Full article

By using virtual surgical planning (VSP) and 3D printed guides, complex maxillofacial defects can be reconstructed with high accuracy and predictability. A fully digital workflow resulting in a modular all-in-one 3D printed guide system for fibula osteotomies, bone segment positioning, fully guided dental implant placement and dental prosthesis fixation for mandibular reconstruction was developed at Ghent University Hospital. A follicular ameloblastoma of the left mandible was resected in a 28-year-old male. The defect was reconstructed with a two-segment fibular free flap with immediate placement of three dental implants and immediate implant loading with a screw-retained bridge. A split thickness skin graft and Elemental PerioPlast were used as wound dressing. Comparison of the preoperative planning with the postoperative CT-scan showed a deviation immediately after surgery, which was no longer present at the 6-month follow-up. The patient achieved a stable occlusion and 44 mm mouth opening and reported high satisfaction. This case illustrates that fully digital, immediate mandibular reconstruction with simultaneous implant placement and prosthetic rehabilitation is feasible and accurate and enhances early functional recovery. Future improvements in intraoperative validation may further refine accuracy and reproducibility in complex oncologic reconstructions. Full article

Background: Inguinoscrotal sarcomas are a rare sarcoma subtype. The treatment of choice is radical inguinal orchiectomy with wide local resection of the surrounding soft tissues. However, consensus regarding prognostic factors is lacking. We present our experience at a referral sarcoma center concerning the management, oncologic results, and prognostic factors pertaining to this disease. Methods: We conducted a retrospective analysis of patients who underwent surgery for inguinoscrotal sarcomas between 2005 and 2023 at a sarcoma referral hospital. Results: The study included 39 patients. The most frequent histology was liposarcoma. Seven patients required surgical reconstruction with a microvascularized free flap. Four patients presented major postoperative complications. Mean follow-up was 46 months. Overall survival rates were 97.4%, 81.7%, and 64.8% at one, three, and five years. High-grade tumors were correlated with worse overall and disease-free survival. Conclusions: The chance finding of a sarcoma in the inguinal region poses a diagnostic and therapeutic dilemma when considering options for treatment with curative intent. Vascular and muscle resection followed by vascular and/or free flap reconstruction may be necessary to achieve complete surgical resections; therefore, a multidisciplinary approach is needed. A preoperative biopsy should be performed to establish the histological grade, which may be the main prognostic factor. Full article

Flap reconstruction remains a cornerstone after oncologic resection, trauma, and complex wounds, yet partial necrosis, venous congestion, and delayed healing continue to drive morbidity and unplanned re-exploration. Even when macroscopic inflow and outflow are re-established, distal and border-zone tissue may remain constrained by microcirculatory dysfunction. This review frames flap compromise as a biomimetics-relevant failure of a hierarchical transport network and summarizes the vascular repair mechanisms that regenerative interventions aim to replicate. We outline key concepts governing flap perfusion, including angiosomes, choke vessels, endothelial barrier failure, mural cell support, and immune regulation within the angiogenic niche, and relate these to no-reflow, thrombo-inflammation, and impaired vascular regeneration. We then synthesize regenerative strategies aimed at durable reperfusion, spanning recombinant factors, gene and nucleic acid delivery, cell-based therapies, cell-free biologics, including extracellular vesicles and platelet-derived products, pharmacologic modulators, and biomaterial platforms that localize and sustain bioactivity. Translation will require functional perfusion endpoints, standardized reporting of delivery parameters, and safety-conscious designs that minimize aberrant angiogenesis and vector-related risks in post-resection settings. Full article

This paper investigates the flight kinematics and unsteady aerodynamics of butterfly flight using high-speed schlieren imaging. Butterfly trajectories are reconstructed to examine flight control mechanisms, with particular emphasis on thorax-driven manoeuvring and body reorientation. By reconstructing free-flight trajectories utilizing image recognition algorithms, we isolate the mechanisms of flight control, with particular emphasis on how thoracic oscillation drives manoeuvring and body reorientation. Phase-resolved analysis reveals distinct wingbeat modes, including clap-and-fling motions associated with hovering and low-speed ascent. Schlieren visualization further captures a detailed view of the wake topology, displaying the formation and evolution of wingtip vortices during the downstroke, as well as attached and entrained flow structures during cupped wing configurations. The results demonstrate the strong coupling between body dynamics, wing kinematics, and wake structure, highlighting how butterflies combine aerodynamic and inertial mechanisms to achieve efficient lift generation and control. These findings provide biomimetic insights relevant to the design of flapping wing micro air vehicles, particularly for low-speed flight, hover efficiency, and passive stability and control through body–wing coupling. Full article

Background/Objectives: Locally advanced midface malignant tumors require extensive resection, resulting in complex defects involving bone and multiple soft tissue structures. Reconstructing these substantial defects presents a significant challenge to restore both function and aesthetics. This study aims to compare the functional and aesthetic outcomes of chimeric free flaps versus single free flaps in midface microvascular reconstructions. Methods: This retrospective analysis included fifty consecutive patients with Type III Cordeiro defects who underwent midface reconstruction with free tissue transfer between 2020 and 2024. The cohort included fourteen patients who received prefabricated chimeric flaps and thirty-six patients who received single free flaps. Outcomes were assessed six months postoperatively using a modified University of Washington Quality of Life Questionnaire (UW-QOL), analyzing domains including speech, chewing, sensation, appearance, pain, and social activity. Statistical analysis was performed using the Mann–Whitney U test. Results: In the chimeric flap group, no major flap necrosis or complications were observed. In unadjusted comparisons, the chimeric flap group showed higher transformed UW-QOL scores in several domains. Statistically significant between-group differences were observed for opening and speech (p = 0.004), change in appearance (p = 0.022), sensation (p = 0.011), and social activity (p = 0.006). Aesthetic outcomes, assessed via patient rating of appearance, were also significantly higher in unadjusted comparisons with the chimeric flap approach. Furthermore, in Type IIIa defects, titanium mesh successfully provided reliable orbital support. Conclusions: Chimeric free flaps represent a feasible reconstructive option in selected cases of complex maxillary and midface reconstruction. Their main advantages—providing the proper amount of specific, well-vascularized tissue and offering greater mobility of components— may be associated with more favorable functional, aesthetic, and social outcomes in unadjusted comparisons compared to reconstruction using single free flaps. Full article

Background: Computer-aided design and manufacturing (CAD/CAM) technology has been increasingly adopted for mandibular and maxillary reconstruction using fibula free flaps. However, its clinical and economic advantages over the conventional freehand technique remain debated. The objective of this study was to compare perioperative outcomes and institutional costs between CAD/CAM-guided and conventional freehand fibula flap reconstructions. Methods: An ambispective observational study was conducted including patients who underwent mandibular or maxillary reconstruction with an osteocutaneous free fibula flap between 2017 and 2024. Reconstructions were performed either using CAD/CAM-guided virtual surgical planning or the conventional freehand technique. Demographic data, perioperative variables, postoperative outcomes, oncologic margin status, transfusion requirements, and total institutional costs were analyzed. Univariate comparisons were performed between groups, and multivariate linear regression models were used to assess the independent association of CAD/CAM guidance with operative time and hospital length of stay. Results: Fifty-one patients were included (25 CAD/CAM-guided and 26 freehand). CAD/CAM-guided reconstruction was associated with a significantly shorter operative time (542.3 ± 65.8 vs. 604.9 ± 79.5 min; p = 0.0036) and a shorter overall hospital stay (19.6 ± 7.2 vs. 30.6 ± 26.2 days; p = 0.047) in univariate analysis. The need for perioperative blood transfusion was significantly lower in the CAD/CAM group. No significant differences were observed in ICU stay, flap failure, reintervention rate, or postoperative hemoglobin decrease. Although margin status did not differ significantly between groups, a higher proportion of negative margins was observed in the CAD/CAM cohort. In multivariate analysis adjusting for age and perioperative variables, CAD/CAM guidance remained independently associated with reduced operative time, but not with hospital length of stay. Despite higher upfront planning costs, total per-patient cost was lower in the CAD/CAM group due to improved perioperative efficiency. Conclusions: CAD/CAM-guided fibula free flap reconstruction is a safe and effective technique that is associated with reduced operative time and lower transfusion requirements while maintaining comparable oncologic outcomes. When perioperative efficiency gains are achieved, these advantages may offset the higher planning costs, resulting in overall cost savings at the institutional level. CAD/CAM-assisted reconstruction may therefore be particularly advantageous in high-volume oncologic centers and anatomically complex cases. Full article