An alternative therapeutic strategy for infected large bone defect and massive soft-tissue loss of leg-is free flap reconstruction inevitable?

3D and 4D printing of MXene-based composites: from fundamentals to emerging applications

The advent of three-dimensional (3D) and four-dimensional (4D) printing technologies has significantly improved the fabrication of advanced materials, with MXene-based composites emerging as a particularly promising class due to their exceptional electrical, mechanical, and chemical properties. This review explores the fundamentals of MXenes and their composites, examining their unique characteristics and the underlying principles of their synthesis and processing. We highlight the transformative potential of 3D and 4D printing techniques in tailoring MXene-based materials for a wide array of applications. In the field of tissue regeneration, MXene composites offer enhanced biocompatibility and mechanical strength, making them ideal for scaffolds and implants. For drug delivery, the high surface area and tunable surface chemistry of MXenes enable precise control over drug release profiles. In energy storage, MXene-based electrodes exhibit superior conductivity and capacity, paving the way for next-generation batteries and supercapacitors. Additionally, the sensitivity and selectivity of MXene composites make them excellent candidates for various (bio)sensing applications, from environmental monitoring to biomedical diagnostics. By integrating the dynamic capabilities of 4D printing, which introduces time-dependent shape transformations, MXene-based composites can further adapt to complex and evolving functional requirements. This review provides a comprehensive overview of the current state of research, identifies key challenges, and discusses future directions for the development and application of 3D and 4D printed MXene-based composites. Through this exploration, we aim to underscore the significant impact of these advanced materials and technologies on diverse scientific and industrial fields.

Ilizarov Distraction for Congenital Pseudoarthrosis of the Tibia in Adults

OBJECTIVE

The clinical evidence on the management for congenital pseudoarthrosis of the tibia (CPT) in adults is limited. The aim of this study is to assess the functional and radiological outcomes of Ilizarov distraction for treating CPT in adults.

METHODS

A retrospective analysis was conducted. Between 2013 and 2022, an Ilizarov distraction technique was performed on 14 adults (14 limbs) with CPT in our limb deformity center. There were seven females and seven males with a mean age of 33.7 (range, 18 ~ 53) years. The diagnosis of NF-1 was confirmed in seven (50.0%) patients. Eight patients had a history of previous surgical failure. The pseudoarthrosis occurred in the middle and lower tibia in all limbs (six left and eight right). The CPT was classified by Crawford classification and Paley classification. The surgical procedures, external fixation time (EFT), and all outcomes and complications were recorded. The Kolmogorov-Smirnov test was performed to test the normality of the data. The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score at the preoperative and final follow-up was compared by using the Wilcoxon's signed-rank test. The limb-length discrepancy (LLD) and a self-made exercise capacity score at the preoperative and final follow-up were compared by using the student's t-test. The clinical and radiological outcomes were assessed by the Inan scale.

RESULTS

The mean EFT of Ilizarov fixator was 19.5 months (range, 7.3 ~ 39.1). At a median follow-up of 26.8 months (IQR, 20.2 ~ 34.3), bone union of the pseudarthrosis and consolidation of the distraction zone were achieved in all patients. The mean LLD was decreased from 11.3 cm (range, 3.4 ~ 17.3) preoperatively to 1.1 cm (range, 0.3 ~ 3.7) (p < 0.05). The mean or median AOFAS ankle-hindfoot score was improved from 53.5 (IQR, 26.5 ~ 60.5) preoperatively to 63.9 (range, 53 to 73) at final follow-up (p < 0.05). The mean score for exercise capacity were improved from 4.9 (range, 1 to 8) preoperatively to 9.6 (range, 7 ~ 12) at final follow-up (p < 0.05). According to the criteria described by Inan et al., the clinical results were classified as good in 10 and fair in 4, while the radiological results were classified as excellent in three, good in 8, and fair in 2. The success rate was 92.9%, as refracture was defined as treatment failure and occurred in one patient.

CONCLUSION

Ilizarov distraction provided a suitable treatment option for the CPT in adults, as it could achieve a high rate of bone union, a good correction of secondary deformity, a low risk of refracture, and consequently restore a relatively functional limb.

Masquelet combined with free-flap technique versus the Ilizarov bone transport technique for severe composite tibial and soft-tissue defects

BACKGROUND

The treatment of bone and soft-tissue defects after open fractures remains challenging. This study aimed to evaluate the clinical efficacy of the Masquelet technique combined with the free-flap technique (MFFT) versus the Ilizarov bone transport technique (IBTT) for the treatment of severe composite tibial and soft-tissue defects.

METHODS

We retrospectively analysed the data of 65 patients with tibial and soft-tissue defects and Gustilo type IIIB/C open fractures treated at our hospital between April 2015 and December 2021. The patients were divided into two groups based on the treatment method: group A (n = 35) was treated with the MFFT and internal fixation, and group B (n = 30) was treated with the IBTT.

RESULTS

The mean follow-up period was 28 months (range 13-133 months). Complete union of both soft-tissue and bone defects was achieved in all cases. The mean bone-union times were 6 months (range 3-12 months) in group A and 11 months (range 6-23 month) in group B, with a significant difference between the two groups (Z = -4.11, P = 0.001). The mean hospital stay was 28 days (range 14-67 d) in group A which was significantly longer than the mean stay of 18 days (range 10-43 d) in group B (Z = -2.608, P = 0.009). There were no significant differences in the infection rate between group A (17.1 %) and group B (26.7%) (χ2 = 0.867, P = 0.352). The Total Physical Health Scores were 81.51 ± 6.86 (range 67-90) in group A and 75.83±16.14 (range 44-98) in group B, with no significant difference between the two groups (t = 1.894, P = 0.063). The Total Mental Health Scores were significantly higher in group A (90.49 ± 6.37; range 78-98) than in group B (84.70 ± 13.72; range 60-98) (t = 2.232, P = 0.029).

CONCLUSION

Compared with IBTT, MFFT is a better choice of treatment for open tibial and soft-tissue defects with Gustilo IIIB/C fractures. IBTT is the preferred option when the tibial bone defect is large or if the surgeon's expertise in microsurgery is limited.

Photoactivated MXene Nanosheets for Integrated Bone-Soft Tissue Therapy: Effect and Potential Mechanism

The bone defects caused by trauma are inevitably accompanied by soft tissue damage. The development of multifunctional bioactive biomaterials with integrated bone and soft tissue regeneration is necessary and needed urgently in orthopedics. In this work, we found that the photoactivated MXene (Ti3C2Tx) nanosheet showed positive effects on promoting both bone and soft tissue regeneration. We further investigated the detailed effect and potential mechanism of photoactivated MXene on tissue regeneration. Photoactivated MXene shows a good thermal effect and robust antibacterial activity to inhibit the expression of inflammation factors and methicillin-resistant Staphylococcus aureus (MRSA) infection and induces the expression of pro-angiogenic factors and soft tissue wound repair. Photoactivated MXene can also regulate the osteogenic differentiation of adipose-derived stem cells (ADSCs) through the ERK signaling pathway by activating the heat shock protein 70 (HSP70) and enhancing the repair of bone tissue. This work sheds light on the development of bioactive MXene with photothermal activation as an efficient strategy for bone and soft tissue regeneration simultaneously.

Ankle joint salvage and reconstruction by limited ORIF combined with an Ilizarov external fixator for complex open tibial pilon fractures (AO 43-C3.3) with segmental bone defects

Background

Open pilon fractures combined with sizeable segmental bone defects are rare, difficult to treat, and often result in the loss of ankle joint function. The purpose of this study was to determine clinical outcomes in patients with open pilon fractures and sizeable segmental bone defects treated by limited ORIF combined with an Ilizarov external fixator.

Methods

We conducted a retrospective analysis of open pilon fractures with sizeable segmental bone defects treated by limited ORIF combined with the Ilizarov external fixator strategy between July 2014 and August 2019. All patients were included for assessments of fracture healing and infection rates. Ankle functional outcomes were assessed in all patients according to the Paley criteria and American Orthopedic Foot and Ankle Society Score (AOFAS) at least 24 months post-injury.

Results

All patients were followed up for a mean of 41.09 months. The mean bone defect size was 5.64 ± 1.21 cm. The average EFI and BTI were 1.56 ± 0.28 months/cm and 11.12 ± 0.74 days/cm, respectively. According to the Paley evaluation system, the success rate of ankle joint reconstruction was 64% (7/11). The mean score based on the AOFAS functional assessment was 77.73 ± 8.87. Five patients showed posttraumatic arthritis, one of whom required ankle arthrodesis. Three patients developed pin site infections, and one patient developed a deep infection after bone grafting.

Conclusion

The strategy of limited ORIF combined with an Ilizarov external fixator can restore ankle function in most patients with complex open tibial pilon fractures. Ankle stiffness, pin tract infection, and traumatic arthritis were the most common complications associated with this therapy.