One-stage debridement and bone transport versus first-stage debridement and second-stage bone transport for the management of lower limb post-traumatic osteomyelitis

Single versus two-stage management of long-bone chronic osteomyelitis in adults: a systematic review and meta-analysis

BACKGROUND

Chronic osteomyelitis is a debilitating bone infection, characterized by a persistent infection over months to years, poses diagnostic and therapeutic challenges due to its insidious nature and potential for severe bone and soft tissue destruction. This systematic review and meta-analysis aims to review the literature on the treatment of chronic osteomyelitis in long bones and assess cure rates in single versus two-stage surgery.

METHODS

Following the PRISMA guidelines and registered with PROSPERO (ID: CRD42021231237), this review included studies that reported on the management of chronic osteomyelitis in long bones using either a planned one-stage or two-stage surgical approach in adult patients. Databases searched included Medline, Embase, Web of Science, CINAHL, HMIC, and AMED, using keywords related to osteomyelitis, long bones, and surgical management. Eligibility criteria focused on adults with chronic osteomyelitis in long bones, with outcomes reported after a minimum follow-up of 12 months. The meta-analysis utilized the random-effects model to pool cure rates.

RESULTS

The analysis included 42 studies with a total of 1605 patients. The overall pooled cure rate was 91% (CI 95%) with no significant difference observed between single-stage and two-stage surgeries (X2 = 0.76, P > 0.05). Complications were reported in 26.6% of cases in single-stage procedures and 27.6% in two-stage procedures, with prolonged wound drainage noted as a common issue. Dead space management techniques varied across studies, with antibiotic-loaded calcium sulphate beads used in 30.4% of cases.

CONCLUSION

This meta-analysis reveals no significant difference in cure rates between single and two-stage surgical treatments for chronic osteomyelitis in long bones, supporting the efficacy of both approaches. The current treatment strategy should include a combination of debridement, dead space management using local and systematic antibiotics and soft tissue reconstruction if necessary.

Hierarchically Assembled Nanofiber Scaffold Guides Long Bone Regeneration by Promoting Osteogenic/Chondrogenic Differentiation of Endogenous Mesenchymal Stem Cells

Critical-sized segmental long bone defects represent a challenging clinical dilemma in the management of battlefield and trauma-related injuries. The residual bone marrow cavity of damaged long bones contains many bone marrow mesenchymal stem cells (BMSCs), which provide a substantial source of cells for bone repair. Thus, a three-dimensional (3D) vertically aligned nanofiber scaffold (VAS) is developed with long channels and large pore size. The pore of VAS toward the bone marrow cavity after transplantation, enables the scaffolds to recruit BMSCs from the bone marrow cavity to the defect area. In vivo, it is found that VAS can significantly shorten gap distance and promote new bone formation compared to the control and collagen groups after 4 and 8 weeks of implantation. The single-cell sequencing results discovered that the 3D nanotopography of VAS can promote BMSCs differentiation to chondrocytes and osteoblasts, and up-regulate related gene expression, resulting in enhancing the activities of bone regeneration, endochondral ossification, bone trabecula formation, bone mineralization, maturation, and remodeling. The Alcian blue and bone morphogenetic protein 2 (BMP-2) immunohistochemical staining verified significant cartilage formation and bone formation in the VAS group, corresponding to the single-cell sequencing results. The study can inspire the design of next-generation scaffolds for effective long-bone regeneration is expected by the authors.

Mn Single-Atom Nanozyme Functionalized 3D-Printed Bioceramic Scaffolds for Enhanced Antibacterial Activity and Bone Regeneration

Infective bone defect is increasingly threatening human health. How to achieve the optimal antibacterial activity and regenerative repair of infective bone defect simultaneously is a huge challenge in clinic. Herein, this work reports a rational integration of Mn single-atom nanozyme into the 3D-printed bioceramic scaffolds (Mn/HSAE@BCP scaffolds). The integrated Mn/HSAE@BCP scaffolds can catalyze the conversion of H2O2 to produce hydroxyl radical (•OH) and superoxide anion (O2 •-) through cascade reaction. Besides, the prominent thermal conversion efficiency of Mn/HSAE@BCP scaffolds can be utilized for sonodynamic therapy (SDT). The synergetic strategy of chemodynamic therapy (CDT)/SDT enables the sufficient generation of reactive oxygen species (ROS) to kill Staphylococcus aureus (S. aureus) or Escherichia coli (E. coli). Furthermore, the enhanced antibacterial efficacy of Mn/HSAE@BCP scaffolds is beneficial to upregulate the expression of osteogenesis-related markers (such as collagen 1(COL1), Runt-related transcription factor 2 (Runx2), osteocalcin (OCN), and osteoprotegerin (OPG)) in vitro and further promote bone regeneration in vivo. The results demonstrate the good potential of Mn/HSAE@BCP scaffolds for the enhanced antibacterial activity and bone regeneration, which provide an effective method for the treatment of clinical infective bone defect.

Bone transport combined with sequential nailing technique for the management of large segmental bone defects after trauma

Background

Bone transport technique is widely used for the management of large segmental bone defects. However, several reasons may prevent its successful completion, such as poor osteogenesis, docking site nonunion, severe chronic pain and psychological problems. We used sequential nailing technique to solve these problems. The objective of this study was to analyze the clinical effects of our modified technique for the management of large segmental bone defects after trauma.

Methods

Twenty-three patients using bone transport combined with sequential nailing technique in our institution from June 2011 to June 2020 were included and analyzed retrospectively. There were 15 males and eight females. The age ranged from 19 to 64 years. There were eight cases suffering from basic medical diseases. The initial injury was open in 14 patients. Seven cases encountered femoral defects and 16 for tibia. The main reasons for sequential nailing technique were docking site nonunion (nine cases), poor osteogenesis (five cases), severe chronic pain (five cases) and psychological problems (four cases). The residual bone defects after removing the external fixator, operation plans, complications and follow-up time were recorded. Bone defect healing was evaluated by Paley score.

Results

The mean residual bone defects were (2.9 ± 1.9) cm. The mean time in external fixator was (9.5 ± 3.4) months. The average follow-up time was (23 ± 3) months. With respect to complications, two cases suffered from nonunion again and were treated by bone graft with augmented plate fixation. No infection recurrence was found in these cases. The excellent and good rate of bone defect healing was 91.3%.

Conclusion

Bone transport combined with sequential nailing technique could shorten the external fixation time, overcome the inconvenience of the external frame to patients, eliminate chronic pain and be easy for patients to accept. Patients using this modified technique achieved high satisfaction.

Hematoma-like dynamic hydrogelation through natural glycopeptide molecular recognition for infected bone fracture repair

Infected bone fractures remain a major clinical challenge for orthopedic surgeons. From a tissue regeneration perspective, biomaterial scaffolds with antibacterial and osteoinductive activities are highly desired, while advanced materials capable of mimicking the pathological microenvironment during the healing process of infected tissues remain an area deserving more research. Hematoma, the gel-like blood coagulum, plays an essential role in bone fracture repair because of its ability to serve as a dynamic and temporary scaffold with cytokines for both pathogen elimination and tissue healing. In light of this, we designed a dynamic hydrogel with hematoma-like antimicrobial or reparative performance for infected bone fracture repair in this study. The proposed dynamic hydrogel network was based on the reversible recognition of a natural glycopeptide antibiotic vancomycin (Van) and its target dipeptide D-Ala-D-Ala (AA), which could serve as a hematoma-like scaffold for obliterating bacteria in the fracture region and promoting bone repair by introducing an endogenous osteogenic peptide (OGP). In vivo experiments demonstrated that the hydrogel could rapidly eradicate bacteria, improve bone regeneration and restore the local inflammatory microenvironment. Together, findings from this study imply that the use of hematoma-like dynamic hydrogel could lead to a biomimetic revolution in surgical strategies against susceptible bone fractures.

Debridement-Reconstruction-Docking Management System Versus Ilizarov Technique for Lower-Extremity Osteomyelitis

BACKGROUND

Osteomyelitis causes marked disability and is one of the most challenging diseases for orthopaedists to treat because of the considerable rate of infection recurrence. In this study, we proposed and assessed the debridement-reconstruction-docking (DRD) system for the treatment of lower-extremity osteomyelitis. This procedure comprises 3 surgical stages and 2 preoperative assessments; namely, pre-debridement assessment, debridement, pre-reconstruction assessment, reconstruction, and docking-site management. We evaluated the use of the DRD system compared with the Ilizarov technique, which is defined as a 1-stage debridement, osteotomy, and bone transport.

METHODS

This retrospective cohort included 289 patients who underwent either DRD or the Ilizarov technique for the treatment of lower-extremity osteomyelitis at a single institution between January 2013 and February 2021 and who met the eligibility criteria. The primary outcome was the rate of infection recurrence. Secondary outcomes included the external fixator index (EFI), refracture rate, and the Paley classification for osseous and functional results. An inverse-probability-weighted regression adjustment model was utilized to estimate the effect of the DRD system and Ilizarov technique on the treatment of lower-extremity osteomyelitis.

RESULTS

A total of 131 and 158 patients underwent DRD or the Ilizarov technique, respectively. The inverse-probability-weighted regression adjustment model suggested that DRD was associated with a significant reduction in infection recurrence (risk ratio [RR], 0.26; 95% confidence interval [CI], 0.13 to 0.50; p < 0.001) and EFI (-6.9 days/cm, 95% CI; -8.3 to -5.5; p < 0.001). Patients in the DRD group had better Paley functional results than those in the Ilizarov group (ridit score, 0.55 versus 0.45; p < 0.001). There was no significant difference between the 2 groups in the rate of refracture (RR, 0.87; 95% CI, 0.42 to 1.79; p = 0.71) and Paley osseous results (ridit score, 0.51 versus 0.49; p = 0.39).

CONCLUSIONS

In this balanced retrospective cohort of patients with lower-extremity osteomyelitis, the use of the DRD system was associated with a reduced rate of infection recurrence, a lower EFI, and better Paley functional results compared with the use of the Ilizarov technique.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

The Use of Free Fibula Flap in Different Extremities and Our Clinical Results

Background and objectives Plastic, orthopedic, otolaryngology, and oromaxillofacial surgery specialists rely on fibula grafts to solve reconstructive problems. The aim of this study is to discuss the use and results of vascular fibula flaps in the treatment of bone and soft tissue defects in various regions with different etiologies. Materials and methods In our clinic, we treated 32 patients with osteocutaneous fibular flaps due to bone and soft tissue defects of different etiologies and varying anatomical regions. In our study, age, gender, side, cause of injury, surgical technique, treatment results, and complications were evaluated for each patient. Results Of the 32 patients, 25 were male, and 7 were female. The average age is 37.2 (27-56). The mean bone defect size was 10.45 cm. Bone defect occurred in eight patients due to osteomyelitis, eleven patients due to gunshot wounds, nine patients due to pseudoarthrosis, and four patients due to a giant cell tumor. We applied osteocutaneous fibula flap in 27 patients and vascularized fibular flap in five patients. Bone union could not be achieved in four patients, and bone grafting was performed as a secondary surgery. Local infection occurred in five patients, and their treatment was completed with debridement and antibiotic administration. Wound complications occurred in three patients at the donor site, which were treated with debridement and skin grafting. The mean duration of radiological union was three months, and complete union was achieved in the seventh month. Conclusions We have shown in our case series that free vascularized fibula transfer has gained an important place in the field of skeletal reconstruction and is a reliable method for various bone reconstructions.

New bone formation using antibiotic-loaded calcium sulfate beads in bone transports for the treatment of long-bone osteomyelitis

PURPOSE

Bone transport is one of the most frequently used techniques for critical-sized bone defects due to trauma or infection. To fill the defect area and avoid the collapse of soft tissues during transport, some authors have described the use of polymethylmethacrylate or absorbable antibiotic carriers in the form of cylindrical blocks.

METHODS

In this article, we present our experience in the treatment of post-traumatic osteomyelitis of the lower and upper limbs, using a bone transport technique with antibiotic-loaded calcium sulfate in the form of beads. Results With the progressive absorption of calcium sulfate, we observed the formation of a bone-like tissue envelope at the periphery of the defect area. Histological analysis and direct visualization during open revision surgery of the docking site in all patients confirmed the presence of newly formed bone tissue with a high presence of osteoblasts and few osteoclasts; no areas of necrosis or signs of infection were observed. This bone envelope maintained the mechanical protective function of the transport path and docking site, and also provided a biological stimulus to avoid the development of necrotic areas and optimize the consolidation phase. Conclusion Bone transport with calcium sulfate beads improves biological and mechanical support and reduces the number of surgeries required.

Does the Use of Local Antibiotics Affect Clinical Outcome of Patients with Fracture-Related Infection?

This international, multi-center study evaluated the effect of antibiotic-loaded carriers (ALCs) on outcome in patients with a fracture-related infection (FRI) and evaluated whether bacterial resistance to the implanted antibiotics influences their efficacy. All patients who were retrospectively diagnosed with FRI according to the FRI consensus definition, between January 2015 and December 2019, and who underwent surgical treatment for FRI at any time point after injury, were considered for inclusion. Patients were followed-up for at least 12 months. The primary outcome was the recurrence rate of FRI at follow-up. Inverse probability for treatment weighting (IPTW) modeling and multivariable regression analyses were used to assess the relationship between the application of ALCs and recurrence rate of FRI at 12 months and 24 months. Overall, 429 patients with 433 FRIs were included. A total of 251 (58.0%) cases were treated with ALCs. Gentamicin was the most frequently used antibiotic (247/251). Recurrence of infection after surgery occurred in 25/251 (10%) patients who received ALCs and in 34/182 (18.7%) patients who did not (unadjusted hazard ratio (uHR): 0.48, 95% CI: [0.29-0.81]). Resistance of cultured microorganisms to the implanted antibiotic was not associated with a higher risk of recurrence of FRI (uHR: 0.75, 95% CI: [0.32-1.74]). The application of ALCs in treatment of FRI is likely to reduce the risk of recurrence of infection. The high antibiotic concentrations of ALCs eradicate most pathogens regardless of susceptibility test results.

Cefazolin/BMP-2-Loaded Mesoporous Silica Nanoparticles for the Repair of Open Fractures with Bone Defects

The study aimed to explore the feasibility of a nanodrug delivery system to treat open fractures with bone defects. We developed a cefazolin (Cef)/bone morphogenetic protein 2 (BMP-2)@mesoporous silica nanoparticle (MSN) delivery system; meanwhile, Cef/MBP-2@ poly(lactic-co-glycolic acid) (PLGA) was also developed as control. For the purpose of determining the osteogenic and anti-inflammatory actions of the nanodelivery system, we cultured bone marrow mesenchymal stem cells (BMSCs) and constructed a bone defect mouse model to evaluate its clinical efficacy. After physicochemical property testing, we determined that MSN had good stability and did not easily accumulate or precipitate and it could effectively prolong the Cef’s half-life by nearly eight times. In BMSCs, we found that compared with the PLGA delivery system, MSNs better penetrated into the bone tissue, thus effectively increasing BMSCs’ proliferation and migration ability to facilitate bone defect repair. Furthermore, the MSN delivery system could improve BMSCs’ mineralization indexes (alkaline phosphatase [ALP], osteocalcin [OCN], and collagen I [Col I]) to effectively improve its osteogenic ability. Moreover, the MSN delivery system could inhibit inflammation in bone defect mice, which was mainly reflected in its ability to reduce the release of IL-1β and IL-4 and increase IL-10 levels; it could also effectively reduce apoptosis of CD4+ and CD8+ T cells, thus improving their immune function. Furthermore, the percentage of new bones, bone mineral density, trabecular volume, and trabecular numbers in the fracture region were improved in mice treated with MSN, which allowed better repair of bone defects. Hence, Cef/BMP-2@MSN may be feasible for open fractures with bone defects.

Clinical translation of a patient-specific scaffold-guided bone regeneration concept in four cases with large long bone defects

Background

Bone defects after trauma, infection, or tumour resection present a challenge for patients and clinicians. To date, autologous bone graft (ABG) is the gold standard for bone regeneration. To address the limitations of ABG such as limited harvest volume as well as overly fast remodelling and resorption, a new treatment strategy of scaffold-guided bone regeneration (SGBR) was developed. In a well-characterized sheep model of large to extra-large tibial segmental defects, three-dimensional (3D) printed composite scaffolds have shown clinically relevant biocompatibility and osteoconductive capacity in SGBR strategies. Here, we report four challenging clinical cases with large complex posttraumatic long bone defects using patient-specific SGBR as a successful treatment.

Methods

After giving informed consent computed tomography (CT) images were used to design patient-specific biodegradable medical-grade polycaprolactone-tricalcium phosphate (mPCL-TCP, 80:20 ​wt%) scaffolds. The CT scans were segmented using Materialise Mimics to produce a defect model and the scaffold parts were designed with Autodesk Meshmixer. Scaffold prototypes were 3D-printed to validate robust clinical handling and bone defect fit. The final scaffold design was additively manufactured under Food and Drug Administration (FDA) guidelines for patient-specific and custom-made implants by Osteopore International Pte Ltd.

Results

Four patients (age: 23–42 years) with posttraumatic lower extremity large long bone defects (case 1: 4 ​cm distal femur, case 2: 10 ​cm tibia shaft, case 3: complex malunion femur, case 4: irregularly shaped defect distal tibia) are presented. After giving informed consent, the patients were treated surgically by implanting a custom-made mPCL-TCP scaffold loaded with ABG (case 2: additional application of recombinant human bone morphogenetic protein-2) harvested with the Reamer-Irrigator-Aspirator system (RIA, Synthes®). In all cases, the scaffolds matched the actual anatomical defect well and no perioperative adverse events were observed. Cases 1, 3 and 4 showed evidence of bony ingrowth into the large honeycomb pores (pores >2 ​mm) and fully interconnected scaffold architecture with indicative osseous bridges at the bony ends on the last radiographic follow-up (8–9 months after implantation). Comprehensive bone regeneration and full weight bearing were achieved in case 2 ​at follow-up 23 months after implantation.

Conclusion

This study shows the bench to bedside translation of guided bone regeneration principles into scaffold-based bone tissue engineering. The scaffold design in SGBR should have a tissue-specific morphological signature which stimulates and directs the stages from the initial host response towards the full regeneration. Thereby, the scaffolds provide a physical niche with morphology and biomaterial properties that allow cell migration, proliferation, and formation of vascularized tissue in the first one to two months, followed by functional bone formation and the capacity for physiological bone remodelling. Great design flexibility of composite scaffolds to support the one to three-year bone regeneration was observed in four patients with complex long bone defects.

The translational potential of this article

This study reports on the clinical efficacy of SGBR in the treatment of long bone defects. Moreover, it presents a comprehensive narrative of the rationale of this technology, highlighting its potential for bone regeneration treatment regimens in patients with any type of large and complex osseous defects.