[Effectiveness of vacuum sealing drainage combined with modified external fixation antibiotic-impregnated cement semi-open technique in treating chronic ulcer wounds].

Objective: To investigate the effectiveness of debridement-vacuum sealing drainage (VSD)-modified external fixation antibiotic-impregnated cement semi-open technique in treatment of chronic ulcer wounds. Methods: Clinical data of 43 patients with chronic ulcer wounds who met the selection criteria and admitted between January 2019 and June 2023 were retrospectively analyzed. Among them, 23 cases were treated with debridement-VSD-modified external fixation antibiotic-impregnated cement semi-open technique (improved group), and 20 cases were treated with debridement-VSD-traditional antibiotic-impregnated cement technique (control group). There was no significant difference in gender, age, constituent ratio of patients with type 2 diabetes mellitus, constituent ratio of patients with smoking history, body mass index, wound site, and other baseline data between the two groups ( P>0.05). The healing quality and healing time, the positive rate of bacterial culture after bone cement coating, the loosening rate of bone cement, the number of operations, the number of hospitalizations, the length of hospitalization, and the cost of hospitalization were recorded and compared between the two groups. Results: Compared with the control group, the positive rate of bacterial culture after bone cement coating and the loosening rate of bone cement in the improved group was significantly lower, as well as the number of operations, the number of hospitalizations, the length of hospitalization, and hospitalization cost significantly reduced ( P<0.05). Wound repair was completed in both groups without amputation. The wound healing quality of the improved group was better than that of the control group and the wound healing time was shorter, the differences were significant ( P<0.05). All patients were followed up 1-5 years (mean 3.4 years), and no ulcers recurred during follow-up. Conclusion: Debridement-VSD-modified external fixation antibiotic-impregnated cement semi-open technique in the treatment of chronic ulcer wounds can effectively reduce the loosening rate of bone cement, facilitate the induced membrane formation and wound healing, and significantly reduce the number of operations and shorten the length of hospital stay.

Induced membrane technique for malignant bone tumours of the humerus.

PURPOSE: The aim of this study was to report on mid- to long-term results following large humeral tumoral resection and reconstruction with the induced-membrane technique in skeletally immature patients suffering from primary malignant bone tumours. METHODS: A retrospective analysis identified all children who underwent the two stages of a humeral reconstruction using the induced-membrane technique for primary malignant humerus tumours between 2002 and 2020. Functional assessment was conducted by an independent observer using the Musculoskeletal Tumor Society (MSTS) scoring system for the upper limb. Radiological assessment was performed by two independent observers and the healing index was calculated (i.e., months/cm). RESULTS: Eight adolescents (5 osteosarcomas and 3 Ewing sarcoma), with a mean age of 14.2 years (SD = 2.7), were included. The mean length of the bone resection was 17.4 cm (SD = 3.8), and the mean delay of the resection and reconstruction stages was 9.4 months (SD = 4). The mean follow-up was 6.6 years (SD = 4.3). The mean MSTS score was 77.4% and the global average healing index was 1.04 months/cm (SD = 2.2). Four complications (i.e., prominence device, fracture, aseptic pseudarthrosis, radial palsy) and one local recurrence were observed in four patients, requiring four unplanned surgical procedures in three patients. One patient died fourteen years after the initial treatment due to a lung recurrence. CONCLUSION: The induced-membrane technique is an effective and safe alternative for reconstructing large humeral bone defects after tumour resection in adolescents. Although this is a two-stage technique, it gives good functional results comparable to other strategies found in the literature. LEVEL OF EVIDENCE: IV.

Induced membrane technique and intramedullary beaming for the extensive bone defect of the talonavicular joint: A case report and literature review.

Cases involving both the induced membrane technique (IMT) and intramedullary beaming (IB) are generally rare. Here, we report such a case in an 83-year-old man who presented with left midfoot pain. Pyogenic arthritis was suspected based on clinical findings, and curettage was performed, revealing an extensive bone defect. The patient was clinically diagnosed with seronegative rheumatoid arthritis (RA). Therefore, the patient underwent both IMT and IB for the extensive bone defect in the talus and navicular regions caused by seronegative RA. The patient exhibited satisfactory short-term outcomes.

The Treatment of Very Large Traumatic Bone Defects of the Tibia With a Polycaprolactone-Tricalcium Phosphate 3D-Printed Cage: A Review of Three Cases.

The need for an artificial scaffold in very large bone defects is clear, not only to limit the risk of graft harvesting but also to improve clinical success. The use of custom osteoconductive scaffolds made from biodegradable polyester and ceramics can be a valuable patient-friendly option, especially in case of a concomitant infection. Multiple types of scaffolds for the Masquelet procedure (MP) are available. However, these frequently demonstrate central graft involution when defects exceed a certain size and the complication rates remain high. This paper describes three infected tibial defect nonunions with a segmental defect over 10 centimeters long treated with a three-dimensional (3D)-printed polycaprolactone-tricalcium phosphate (PCL-TCP) cage in combination with biological adjuncts. Three male patients, between the ages of 37 and 47, were treated for an infected tibial defect nonunion after sustaining Gustilo grade 3 open fractures. All had a segmental midshaft bone defect of more than 10 centimeters (range 11-15cm). First-stage MPs consisted of extensive debridement, external fixation, and placement of anterior lateral thigh flaps. Positive cultures were obtained from all patients during this first stage, which were treated with specific systemic antibiotics for 12 weeks. The second-stage MP was carried out at least two months after the first stage. CT scans were obtained after the first stage to manufacture defect-specific cages. In the final procedure, a custom 3D-printed PCL-TCP cage (Osteopore, Singapore) was placed in the defect in combination with biological adjuncts (BMAC, RIA-derived autograft, iFactor, and BioActive Glass). Bridging of the defect, assessed at six months by CT, was achieved in all cases. SPECT scans six months post-operatively demonstrated active bone regeneration, also involving the central part of the scaffold. All three patients regained function and reported less pain with full weight bearing. This case report shows that 3D-printed PCL-TCP cages in combination with biological adjuncts are a novel addition to the surgical treatment of very large bone defects in (infected) post-traumatic nonunion of the tibia. This combination could overcome some of the current drawbacks in this challenging indication.

[Modified Masquelet technique : Technique of the induced membrane in the course of time]. / Modifizierte Masquelet-Plastik : Technik der induzierten Membran im Wandel der Zeit.

The reconstruction of long bone defects as a result of primary traumatic, secondary infection or tumor-related loss of substance continues to represent a surgical challenge. Callus distraction via segment transport, vascularized bone transfer and the induced membrane technique (IMT) are established methods of reconstruction. In recent decades IMT has experienced increasing popularity due to its practicability, reproducibility and reliability. At the same time, the original technique has undergone numerous modifications. The results are correspondingly heterogeneous. This overview is intended to explain the basic principles of IMT and to provide an overview of the various modifications and their complications.

Curvature-Assisted Vesicle Explosion Under Light-Induced Asymmetric Oxidation.

Exposure of cell membranes to reactive oxygen species can cause oxidation of membrane lipids. Oxidized lipids undergo drastic conformational changes, compromising the mechanical integrity of the membrane and causing cell death. For giant unilamellar vesicles, a classic cell mimetic system, a range of mechanical responses under oxidative assault has been observed including formation of nanopores, transient micron-sized pores, and total sudden catastrophic collapse (i.e., explosion). However, the physical mechanism regarding how lipid oxidation causes vesicles to explode remains elusive. Here, with light-induced asymmetric oxidation experiments, the role of spontaneous curvature on vesicle instability and its link to the conformational changes of oxidized lipid products is systematically investigated. A comprehensive membrane model is proposed for pore-opening dynamics incorporating spontaneous curvature and membrane curling, which captures the experimental observations well. The kinetics of lipid oxidation are further characterized and how light-induced asymmetric oxidation generates spontaneous curvature in a non-monotonic temporal manner is rationalized. Using the framework, a phase diagram with an analytical criterion to predict transient pore formation or catastrophic vesicle collapse is provided. The work can shed light on understanding biomembrane stability under oxidative assault and strategizing release dynamics of vesicle-based drug delivery systems.

Management of Infected Gap Non-union of Distal Femur with Induced Membrane Technique using Limb Reconstruction System Followed by Augmentation Plating and Bone Grafting: A Case Report.

Introduction: Distal femur fractures are high-velocity injuries which accounts for 7-10% of all femoral fractures of which 5-10% are open fractures. Despite advances in techniques and implants, treatment remains a challenge, in many situations due to increased risk of infection, non-union and loss of range of motion. Surgical management of such complex injury includes radical debridement with stabilization followed by management of gap non-union with appropriate techniques and restores the range of motion. Case Report: We present a case of 20-year-old man who had suffered multiple orthopedic trauma following accident. The patient had open comminuted fracture of the right distal femur, closed fracture of the same side tibia shaft, and right side closed both bone forearm shaft fracture. The patient was initially treated with debridement and knee-spanning limb reconstruction system (LRS). The patient developed infection and subsequently osteomyelitis of the distal femur shaft and gap non-union of 8 cm. The patient was operated for two-stage-induced membrane technique (IMT) and bone grafting using LRS followed by non-vascularized fibula strut grafting and plating. Quadriceps contracture was later on treated with quadricepsplasty to get good functional and radiological outcome. Conclusion: A case of open distal femur comminuted fracture with a very small distal fragment complicated with osteomyelitis and gap non-union. We have shown that the use of IMT followed by non-vascularized fibula strut grafting and plating along with quadricepsplasty can give a very good outcome.

Treatment of infected humeral shaft nonunion and presumed aseptic nonunion with positive intraoperative cultures: a retrospective single-center study.

PURPOSE: The management of infected humeral shaft nonunion (HSN) remains challenging due to the lack of consensus and the potential for occult infection. The aim of this study was to evaluate a surgical strategy based on a two-stage treatment for suspected infection or a one-stage treatment for infection diagnosed retrospectively based on systematic bacteriological sampling. METHODS: We retrospectively reviewed 16 patients with a median age of 36 years who were treated for septic HSN: 9 patients underwent a two-stage procedure using the induced membrane technique, and 7 patients were treated in a single stage. Revision parameters included achieving bone union, its time frame, and a functional assessment based on joint motion and the Quick-DASH score. RESULTS: At a median follow-up of 47.5 months, 12 out of 16 patients were cured with acquired bone union and no septic recurrence. The median time to bone union was 5.5 months. Smoking and previous surgeries were adverse factors for bone healing. Radiological and functional outcomes were comparable between patients treated in a single stage and those treated in two stages. CONCLUSIONS: This study confirms the relevance of one-stage surgery for HSN with occult infection and the value of systematic bacteriological sampling during the revision of humeral diaphyseal osteosynthesis.

Assessment, Diagnosis and Management Strategies for Forearm Shaft Non-union: A Contemporary Perspective.

Forearm non-union poses a challenge in orthopaedic surgery due to its intricate anatomy and functional significance. This review provides a comprehensive overview of the assessment, diagnosis and management of forearm non-union. Initial evaluation involves a meticulous history, physical examination and imaging studies to identify factors contributing to non-union, including infection. Surgical approaches are discussed, with emphasis on restoring biomechanical stability and promoting bone healing. Treatment options range from autografts to allografts, with considerations for vascularised bone transfers in complex cases. Decision-making strategies are outlined, considering patient-specific factors and individualised treatment plans. Special considerations for specific types of forearm non-unions are addressed, along with postoperative care protocols to optimise healing and functional outcomes. Overall, this review aims to provide clinicians with a comprehensive understanding of forearm non-union management based on current evidence and clinical practice. Level of Evidence: Level V (Therapeutic).

Hemi-Masquelet technique and nailing in a circumferential bone defect of 7 cm after open femoral shaft fracture. A case report.

The treatment of Gustilo-Anderson type III open femoral fracture with large segmental bone defect remains a challenge for orthopedic trauma surgeons. The aims of management are first to prevent the risk of infection and then to reconstruct the bone loss with correct alignment and length. The induced membrane technique (or Masquelet technique) was initially described for tibia nonunion but became over the years an established procedure to treat any kind of large bone defect. The case of a 22-year old male who sustained an open femoral shaft fracture with a circumferential 7-cm bone defect after a car accident is presented. Given the critical size of the bone loss, we chose to manage this patient using a modified-Masquelet technique, in which we stabilized the fracture by an intramedullary femoral nail and filled only the lateral side of the defect with a cement spacer. He went on to have a full and successful union of his fracture 16-weeks after the second stage surgery. The final functional outcomes were excellent allowing the patient to resume all activities without restriction.

A Novel Method to Assess Healing of Segmental Bone Defects using the Induced Membrane Technique.

OBJECTIVE: Clinical concerns exist regarding the quality of bony consolidation in the context of the induced membrane technique. This study evaluates the clinical process of bone grafting in the second stage of induced membrane bone union in patients with tibial bone defects to infer the possibility of non-union and establish a reliable and effective evaluation method combined with computed tomography (CT) to assess fracture healing. METHODS: Patients with tibial bone defects who underwent the induced membrane technique at our hospital between February 2017 and February 2020 were retrospectively analyzed. The Hounsfield unit (HU) values of the patients were evaluated at different times during the second stage of bone grafting. Bone healing at the boundary value of the 120 HU output threshold (-1024 HU-3071 HU) was directionally selected, and the changes in the growth volume of union (new bone volume [selected according to HU value]/bone defect volume) were compared with analyzing individual class bone union. Method 1 involved X-rays revealing that at least three of the four cortices were continuous and at least 2 mm thick, with the patient being pain free. For Method 2, new bone volume (selected according to HU value/bone defect volume) at the stage was compared with analyzing individual class healing. Receiver operating characteristic curve analysis was used for Methods 1 and 2. RESULTS: A total of 42 patients with a segmental bone defect with a mean age of 40.5 years (40.5 ± 8.3 years) were included. The relationship between bone graft volume and time variation was analyzed by single factor repeated variable analysis (F = 6.477, p = 0.016). Further, curve regression analysis showed that the change in bone graft volume over time presented a logarithmic curve pattern (Y = 0.563 + 0.086 × ln(X), Ra2 = 0.608, p = 0.041). ROC curve analysis showed that Method 2 is superior to Method 1 (AUC: 86.3% vs. 68.3%, p < 0.05). CONCLUSION: The induced membrane technique could be used to treat traumatic long bone defects, with fewer complications and a higher healing rate. The proposed imaging grading of HU (new bone volume/bone defect volume) can be used as a reference for the quality of bony consolidation with the induced membrane technique.

Membrane Formed Around Liquid Nitrogen-treated Bone Promotes Osteogenesis and Revitalization in a Rat Model.

BACKGROUND/AIM: This study aimed to investigate the structure and functions of the membrane formed around liquid nitrogen-treated bones in the osteogenesis and revitalization of frozen bone using a rat model. MATERIALS AND METHODS: Segmental defects were created in femurs of rats, and resected bones treated with liquid nitrogen [frozen bone (FB) group, n=20] or polymethylmethacrylate (PMMA group; n=20) were implanted as spacers. Histological analysis and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) of the membrane around each spacer were performed for bone morphogenetic protein 2 (BMP2), transforming growth factor (TGF)-ß1, and vascular endothelial growth factor (VEGF). Furthermore, in week 2, spacers were removed from both groups (n=5 each), and autologous cancellous bone (ACB) harvested from the ilium was grafted into the defect. Radiological analysis was performed until bone union was observed. RESULTS: In week 2, similar two-layered membrane structures were observed in both groups; these matured into fibrous tissues over time. At each evaluation point, qRT-PCR showed higher expression of all factors in the FB than in the PMMA group. In the ACB graft model, the mean period to bone union and new bone volume were significantly shorter and greater, respectively, in the FB. Chondrocytes invaded the osteotomy site from the membrane in the FB, suggesting that endochondral ossification may occur and be related to osteogenesis. Additionally, fibroblasts and capillaries in the membrane invaded the surface of treated bone in week 2, and osteocytes were observed around them in weeks 6 and 8. CONCLUSION: Fibrous membranous tissue formed around liquid nitrogen-treated bones may be vital for osteogenesis and revitalization of frozen bones.

Comparison of limb reconstruction with vascularized fibula flap versus induced membrane technique in 54 pediatric cases over 16 years.

BACKGROUND: Children's bone loss of limbs represents a significant challenge for surgeons, especially given that children are growing individuals. In the pediatric population, we compared bone reconstruction using vascularized fibula flaps with the induced membrane technique. The primary purpose of this study was to evaluate the delay and quality of consolidation. METHODS: Data from patients who underwent limb reconstruction using either the fibula flap or the induced membrane were retrospectively collected from files across two centers. Perioperative and long-term complications were documented, along with functional and aesthetic outcome. RESULTS: Between 2004 and 2020, 31 children underwent limb reconstruction using a fibula flap, and 13 patients were treated using the induced membrane technique. The etiologies included 76% tumors, 20% congenital pseudarthroses, and 3.7% infections. The median size of the bone resection was 12.5 cm (range: 1.8 to 31 cm). The median time to consolidation after free fibula flap transfer was 10 months (range: 2 to 55 months) versus 7.5 months (range: 1 to 64 months) for the Masquelet technique (p = 0.54). Limb length inequality occurred in 52% of fibula cases and 39% of the induced membrane cases (p = 0.55). CONCLUSIONS: Both of free fibula flap and the induced membrane technique are effective options for bone reconstructing long bones in children. These techniques yield good functional outcomes and have comparable consolidation times.

Boosting Upconversion Efficiency in Optically Inert Shelled Structures with Electroactive Membrane through Electron Donation.

This study innovatively addresses challenges in enhancing upconversion efficiency in lanthanide-based nanoparticles (UCNPs) by exploiting Shewanella oneidensis MR-1, a microorganism capable of extracellular electron transfer. Electroactive membranes, rich in c-type cytochromes, are extracted from bacteria and integrated into membrane-integrated liposomes (MILs), encapsulating core-shelled UCNPs with an optically inactive shell, forming UCNP@MIL constructs. The electroactive membrane, tailored to donate electrons through the inert shell, independently boosts upconversion emission under near-infrared excitation (980 or 1550 nm), bypassing ligand-sensitized UCNPs. The optically inactive shell restricts energy migration, emphasizing electroactive membrane electron donation. Density functional theory calculations elucidate efficient electron transfer due to the electroactive membrane hemes' highest occupied molecular orbital being higher than the valence band maximum of the optically inactive shell, crucial for enhancing energy transfer to emitter ions. The introduction of a SiO2 insulator coating diminishes light enhancement, underscoring the importance of unimpeded electron transfer. Luminescence enhancement remains resilient to variations in emitter or sensitizing ions, highlighting the robustness of the electron transfer-induced phenomenon. However, altering the inert shell material diminishes enhancement, emphasizing the role of electron transfer. This methodology holds significant promise for diverse biological applications. UCNP@MIL offers an advantage in cellular uptake, which proves beneficial for cell imaging.

Mechanisms of the Masquelet technique to promote bone defect repair and its influencing factors.

The Masquelet technique, also known as the induced membrane technique, is a surgical technique for repairing large bone defects based on the use of a membrane generated by a foreign body reaction for bone grafting. This technique is not only simple to perform, with few complications and quick recovery, but also has excellent clinical results. To better understand the mechanisms by which this technique promotes bone defect repair and the factors that require special attention in practice, we examined and summarized the relevant research advances in this technique by searching, reading, and analysing the literature. Literature show that the Masquelet technique may promote the repair of bone defects through the physical septum and molecular barrier, vascular network, enrichment of mesenchymal stem cells, and high expression of bone-related growth factors, and the repair process is affected by the properties of spacers, the timing of bone graft, mechanical environment, intramembrane filling materials, artificial membrane, and pharmaceutical/biological agents/physical stimulation.

Induced membrane technique using beta-tricalcium phosphate for reconstruction of clavicle bone defect after fracture related infection - A case report.

The induced membrane technique (IMT) is among the most innovative reconstructive methods for clavicle defects after fracture-related infection (FRI). Herein, we report a case in which a clavicle bone defect after FRI was reconstructed with an autogenous cancellous bone graft mixed with ß-tricalcium phosphate (ß-TCP) in the second stage of the IMT. A 62-year-old male patient with left clavicle fracture underwent open reduction and internal fixation. Refracture occurred immediately after the implant was removed. The patient was diagnosed with FRI after reopen reduction and internal fixation and was then referred to our hospital. The surgery was performed using the IMT. In the second stage of the IMT, the bone defect was filled with an autogenous cancellous bone mixed with wool-type ß-TCP. At 8 months after surgery, the nonunion area had fused, and the patient had no restrictions in activities of daily living. The IMT with ß-TCP can be a reconstructive method for bone defects after clavicular nonunion.

Application of double plate fixation combined with Masquelet technique for large segmental bone defects of distal tibia: a retrospective study and literature review.

BACKGROUND: There is no effective consensus on the choice of internal fixation method for the Masquelet technique in the treatment of large segmental bone defects of the distal tibia. Thus, the study aimed to investigate the outcomes of the Masquelet technique combined with double plate fixation in the treatment of large segmental bone defects. METHODS: This was a retrospective study involving 21 patients with large segmental bone defects of the distal tibia who were treated between June 2017 and June 2020. The length of bone defect ranged from 6.0 cm to 11 cm (mean, 8.19 cm). In the first stage of treatment, following complete debridement, a cement spacer was placed to induce membrane formation. In the second stage, double plate fixation and autologous cancellous bone grafting were employed for bone reconstruction. Each patient's full weight-bearing time, bone healing time, and Iowa ankle score were recorded, and the occurrence of any complications was noted. RESULTS: All patients were followed up for 16 to 26 months (mean, 19.48 months). The group mean full weight-bearing time and bone healing time after bone grafting were 2.41 (± 0.37) months and 6.29 (± 0.66) months, respectively. During the treatment, one patient had a wound infection on the medial side of the leg, so the medial plate was removed. The wound completely healed after debridement without any recurrence. After extraction of iliac bone for grafting, one patient had a severe iliac bone defect, which was managed by filling the gap with a cement spacer. Most patients reported mild pain in the left bone extraction area after surgery. The postoperative Iowa ankle score range was 84-94 (P < 0.05). In this cohort, 15 cases were rated as "excellent", and 6 cases as "good" on the Iowa ankle scoring system. CONCLUSION: The Masquelet technique combined with double plate fixation is a safe and effective method for the treatment of large segmental bone defects of the distal tibia.

Induced-membrane technique for lower limb reconstruction after malignant bone tumour resection in paediatric patients: Complication and re-operation rates.

BACKGROUND: The objective of this study was to assess the complication and re-operation rates, evaluate the risk of non-union, and describe the functional outcomes at last follow-up in children and adolescents after lower-limb malignant tumour resection and reconstruction using the induced-membrane technique. HYPOTHESIS: Weight-bearing resumption 6 weeks after the second stage of the induced-membrane procedure promotes bone healing. MATERIAL AND METHODS: The study included 13 patients (9 with osteosarcoma, 3 with Ewing's sarcomas, and 1 with alveolar sarcoma) managed between 2000 and 2020 by oncological femoral or tibial resection followed, at a distance from adjuvant chemotherapy, by reconstruction using the induced-membrane technique. Non-union was the primary outcome measure and the MusculoSkeletal Tumor Society (MSTS) lower-limb functional score was the secondary outcome measure. Mean follow-up was 6.1 years (range, 2.0-12.7). At last follow-up, mean age was 18.1 years (range, 11.0-26.0) and the mean MSTS score was 66.6% (37.0-93.0%). RESULTS: After the second reconstruction stage, 8 complications developed in 6 patients (46%). Either a complication or limb-length inequality required 12 re-operations in 8 patients (61.5%). Non-union occurred after reconstruction in 5 (38.5%) patients. Early resumption of 50% weight-bearing 6 weeks after reconstruction was associated with bone healing (p=0.02). CONCLUSION: The non-union rate was 38.5%. Partial, 50% weight-bearing with two elbow crutches and an orthosis, if allowed by construct stability, may promote bone healing. LEVEL OF EVIDENCE: IV.

The Impact of Defect Size on Bone Healing in Critical-Size Bone Defects Investigated on a Rat Femur Defect Model Comparing Two Treatment Methods.

Critical-size bone defects up to 25 cm can be treated successfully using the induced membrane technique established by Masquelet. To shorten this procedure, human acellular dermis (HAD) has had success in replacing this membrane in rat models. The aim of this study was to compare bone healing for smaller and larger defects using an induced membrane and HAD in a rat model. Using our established femoral defect model in rats, the animals were placed into four groups and defects of 5 mm or 10 mm size were set, either filling them with autologous spongiosa and surrounding the defect with HAD or waiting for the induced membrane to form around a cement spacer and filling this cavity in a second operation with a cancellous bone graft. Healing was assessed eight weeks after the operation using µ-CT, histological staining, and an assessment of the progress of bone formation using an established bone healing score. The α-smooth muscle actin used as a signal of blood vessel formation was stained and counted. The 5 mm defects showed significantly better bone union and a higher bone healing score than the 10 mm defects. HAD being used for the smaller defects resulted in a significantly higher bone healing score even than for the induced membrane and significantly higher blood vessel formation, corroborating the good results achieved by using HAD in previous studies. In comparison, same-sized groups showed significant differences in bone healing as well as blood vessel formation, suggesting that 5 mm defects are large enough to show different results in healing depending on treatment; therefore, 5 mm is a viable size for further studies on bone healing.

Induced membrane technique with plate fixation has a lower complication rate than bone transport over a plate for segmental tibial defects larger than 5 cm.

INTRODUCTION: The treatment of segmental tibial bone defects remains a surgical challenge. While Bone Transport (BT) and Induced Membrane Technique (IMT) are effective strategies for regenerating bone, there are few comparative studies between them. This investigation undertakes a comparative analysis of BT and IMT for large segmental tibial defects stabilised through plate fixation. MATERIALS AND METHODS: Patients with segmental tibial defects exceeding 5 cm were prospectively enrolled from 2008 to 2021 in a single institution, with a minimum follow-up duration of two years. All patients underwent either BT or IMT with plate fixation of the tibia. Procedural success, primary union as well as bone and functional outcome scores were compared. Complications, including non-unions, joint contractures and deep infections requiring surgical intervention, were also compared. RESULTS: 41 patients were recruited in total. 28 patients underwent Bone Transport Over a Plate (BTOP), while 13 patients underwent IMT with Plate fixation (IMTP). The procedural success rate trended higher in IMTP compared to BTOP (100% vs. 85.7%). The primary union rate also trended higher in IMTP compared to BTOP (92.3% vs. 79.2%). BTOP and IMTP achieved similar rates of satisfactory bone outcome scores (78.6% vs. 84.6%) and functional outcome scores (75% vs. 76.5%). There was no statistical difference between procedural success, primary union, bone and functional outcome scores. The complication rate in BTOP was 78.6% (22 of 28), including five docking site or regenerate non-unions, eight deep infections and nine joint contractures. IMTP had a 38.5% (5 of 13) complication rate, including one non-union, two deep infections and two joint contractures. The complication rate was 2.04 times higher in BTOP compared to IMTP (p = 0.0117). CONCLUSIONS: BTOP and IMTP are both equally effective techniques for regenerating bone in large tibial bone defects. However, IMTP may be a safer procedure than BTOP, with a lower probability of requiring additional procedures to address complications.