Induced membrane technique for the treatment of bone defects due to post-traumatic osteomyelitis

Alginate-containing 3D-printed hydrogel scaffolds incorporated with strontium promotes vascularization and bone regeneration

Bone defects persist as a significant challenge in the field of clinical orthopedics. This study focuses on the fabrication and characterization of 3D-printed composite hydrogel scaffolds composed of sodium alginate, gelatin, and α-tricalcium phosphate (α-TCP) with varying ratios of Strontium ions (Sr2+). These scaffolds aim to address the clinical challenges associated with bone defect repair by providing mechanical support and promoting bone formation and vascularization. The degradation, swelling, mechanical properties, and release profiles of Sr2+ from the hydrogel scaffolds were comprehensively characterized. In vitro tests were conducted to assess cell viability and proliferation, as well as osteogenic and angiogenic gene expression, to investigate the osteogenic and pro-angiogenic potential of the composite hydrogel scaffolds. Furthermore, skull defect simulations were performed, and composite scaffolds with varying Sr2+ ratios were implanted to evaluate their effectiveness in bone repair. This research establishes a foundation for advancing bone tissue engineering through composite scaffolds containing biological macromolecules and strontium, with alginate serving as a key element in enhancing performance and expanding clinical applicability.

Activated allograft combined with induced menbrane technique for the reconstruction of infected segmental bone defects

This study was desinged to evaluate the efficacy and safety of activated allograft combined with the induced membrane technique for reconstruction of infected segment bone defects of lower limbs. A retrospective analysis was conducted on 19 patients from May 2015 to February 2017. After debridements, the bone defects were filled with antibiotic bone cement to form the induced membrane. Autologous mesenchymal stem cells were seeded onto allografts to construct activated allograft, which was implanted into the induced membrane after infection was controlled. The clinical efficacy and complications were observed. 19 patients with 20 infected segment bone defect were evaluated. The average deficit size was 11.08 (4-17) cm in length. After a mean follow-up of 71.84 (61-82) months, bone union was achieved in 16 patients (17 sites), resulting in a final union rate of 84.21% (16/19 patients). The average bone union time was 10.18 (5-28) months. There were 2 patients with recurrence of infection, 3 patients with graft absorption, and 1 patient with malunion due to implant breakage. There were no graft-related complications. This study provides clinical significance for the treatment of patients with insufficient autologous bone.

The induced membrane technique for the management of infected segmental bone defects

Aims

The aim of the present study was to assess the outcomes of the induced membrane technique (IMT) for the management of infected segmental bone defects, and to analyze predictive factors associated with unfavourable outcomes.

Methods

Between May 2012 and December 2020, 203 patients with infected segmental bone defects treated with the IMT were enrolled. The digital medical records of these patients were retrospectively analyzed. Factors associated with unfavourable outcomes were identified through logistic regression analysis.

Results

Among the 203 enrolled patients, infection recurred in 27 patients (13.3%) after bone grafting. The union rate was 75.9% (154 patients) after second-stage surgery without additional procedures, and final union was achieved in 173 patients (85.2%) after second-stage surgery with or without additional procedures. The mean healing time was 9.3 months (3 to 37). Multivariate logistic regression analysis of 203 patients showed that the number (≥ two) of debridements (first stage) was an independent risk factor for infection recurrence and nonunion. Larger defect sizes were associated with higher odds of nonunion. After excluding 27 patients with infection recurrence, multivariate analysis of the remaining 176 patients suggested that intramedullary nail plus plate internal fixation, smoking, and an allograft-to-autograft ratio exceeding 1:3 adversely affected healing time.

Conclusion

The IMT is an effective method to achieve infection eradication and union in the management of infected segmental bone defects. Our study identified several risk factors associated with unfavourable outcomes. Some of these factors are modifiable, and the risk of adverse outcomes can be reduced by adopting targeted interventions or strategies. Surgeons can fully inform patients with non-modifiable risk factors preoperatively, and may even use other methods for bone defect reconstruction.

Non‑contact locking plate: A useful alternative to external fixation in second‑stage treatment of post‑traumatic tibial osteomyelitis

The treatment of infected tibial bone defects can be challenging for the orthopedic surgeon. Therefore, the aim of the present study was to compare the fixation endurance, bone union time, lower limb joint function and complications associated with different fixation methods in the treatment of bone defects caused by debridement in the treatment of post-traumatic osteomyelitis. The clinical data of 55 patients with infected bone defects of the lower extremities following traumatic injury, who had undergone radical debridement between January 2017 and September 2020, were retrospectively analyzed. The patients were divided into three groups according to the type of fixation during reconstruction, namely the external fixation (EX), internal fixation (IX) and non-contact locking plate (LP) groups. The demographic data, time to bone union, bacterial culture results, complications and Self-Rating Anxiety Scale (SAS) scores of the patients were compared among the three groups. The results indicated that the differences in time to bone union and recurrence rates of osteomyelitis among the three groups were not statistically significant. By contrast, functional status after surgery was significantly higher in the LP group compared with the EX group. In total, 8/22 patients (36.4%) in the EX group, 4/13 patients (30.8%) in the IX group and 4/20 patients (20.0%) in the non-contact LP group had shortened limbs and deformed tibia. The SAS assessment results revealed that patients in the non-contact LP group had the lowest rates of moderate and severe anxiety. In conclusion, the results of the present study demonstrate that the non-contact locking plate technique provided stable fixation without any contact between the implant and bone tissues. Therefore, this technique may be viable for use during the reconstruction stage of post-traumatic tibial osteomyelitis.

Evaluating the efficacy of combined flap coverage, antibiotic-loaded bone cement and negative pressure irrigation in traumatic osteomyelitis management

Traumatic osteomyelitis with accompanying soft tissue defects presents a significant therapeutic challenge. This prospective, randomised controlled trial aims to evaluate the efficacy of antibiotic-impregnated bone cement, flap coverage and negative pressure sealed irrigation in the management of traumatic osteomyelitis complicated by soft tissue defects. A total of 46 patients with clinically diagnosed traumatic osteomyelitis and soft tissue defects were randomised into a control group (n = 23) and an observation group (n = 23). The control group underwent standard flap coverage and negative-pressure lavage, while the observation group received an additional treatment with antibiotic-loaded bone cement. Efficacy was measured based on clinical criteria, surgical metrics and morphometric assessment of bone and soft tissue defects. Statistical analyses were performed using SPSS version 27.0. The observation group, treated with an integrated approach of flap coverage, negative pressure wound therapy (NPWT) and antibiotic-impregnated bone cement, demonstrated significantly higher overall treatment efficacy (91.3%) compared to the control group, which received only flap coverage and NPWT (65.2%) (p < 0.01). This enhanced efficacy was evidenced through various outcomes: the observation group experienced reduced surgical times, shorter hospital stays, fewer dressing changes and accelerated wound healing, all statistically significant (p < 0.001). Additionally, a quantitative analysis at 6-month post-treatment revealed that the observation group showed more substantial reductions in both bone and soft tissue defect sizes compared to the control group (p < 0.001). The multi-modal treatment strategy, combining skin flap coverage, antibiotic bone cement and negative-pressure irrigation, showed marked efficacy in treating traumatic osteomyelitis and associated soft tissue defects. This approach accelerated postoperative recovery and lowered costs.

Current Management of Diaphyseal Long Bone Defects-A Multidisciplinary and International Perspective

The treatment of defects of the long bones remains one of the biggest challenges in trauma and orthopedic surgery. The treatment path is usually very wearing for the patient, the patient's environment and the treating physician. The clinical or regional circumstances, the defect etiology and the patient´s condition and mental status define the treatment path chosen by the treating surgeon. Depending on the patient´s demands, the bony reconstruction has to be taken into consideration at a defect size of 2-3 cm, especially in the lower limbs. Below this defect size, acute shortening or bone grafting is usually preferred. A thorough assessment of the patient´s condition including comorbidities in a multidisciplinary manner and her or his personal demands must be taken into consideration. Several techniques are available to restore continuity of the long bone. In general, these techniques can be divided into repair techniques and reconstructive techniques. The aim of the repair techniques is anatomical restoration of the bone with differentiation of the cortex and marrow. Currently, classic, hybrid or all-internal distraction devices are technical options. However, they are all based on distraction osteogenesis. Reconstructive techniques restore long-bone continuity by replacing the defect zone with autologous bone, e.g., with a vascularized bone graft or with the technique described by Masquelet. Allografts for defect reconstruction in long bones might also be described as possible options. Due to limited access to allografts in many countries and the authors' opinion that allografts result in poorer outcomes, this review focuses on autologous techniques and gives an internationally aligned overview of the current concepts in repair or reconstruction techniques of segmental long-bone defects.

Delayed Reconstruction of the Perforator Pedicle Propeller Flap after the Induced Membrane Technique for Gustilo IIIB Open Distal Tibial Fracture

This study aimed to evaluate the safety and efficacy of delayed reconstruction of the perforator pedicle propeller flap after the induced membrane technique in the treatment of Gustilo IIIB open distal tibial fracture, and to evaluate the clinical outcome and complications of two different perforator pedicle propeller flaps.Thirty-four patients with Gustilo IIIB open distal tibial fractures treated by the induced membrane technique and delayed reconstruction of two different perforator pedicle propeller flaps from May 2017 to March 2022 were retrospectively analyzed. Patients were divided into two groups according to the different kinds of perforator pedicle propeller flaps covered. The operation required two stages. The Radiographic Union Score for Tibial fractures (RUST) was used to evaluate the healing of the tibial bone defect. The American Orthopaedic Foot and Ankle Society (AOFAS) score was used to evaluate ankle function. The complications associated with the technique were recorded.The number of serial debridements, excluding those performed during emergency and final operations, was a mean of 2.28 ± 0.83 in the PAPF group. The PAPF group had a mean bone defect length of 6.76 ± 0.69 cm, the median healing time of 13.11 ± 0.96 months, RUST score 12.68 ± 1.63, and AOFAS score of 84.12 ± 6.38. On the other hand the PTAPF group's mean bone defect length was 6.73 ± 0.95 cm, the median healing time 12.63 ± 1.46 months, RUST score 13.73 ± 1.53 and AOFAS score 82.79 ± 5.49. There were no observed significant differences the two groups in the number of serial debridements, bone defect length, bone union time, RUST score, or AOFAS score (p > 0.05). Flap size ranged from 9 × 6 cm2 to 14 × 7 cm2 in the PAPF group and from 9 × 6 cm2 to 13 × 7 cm2 in the PTAPF group. There were no severe complications such as flap-related complications or amputation. The differences in complications in the two groups were not statistically significant.In cases of severe open tibial fracture, the reconstructive method is important. When delayed reconstruction is inevitable, surgeons should first perform radical debridement, followed by vacuum sealing drainage as a bridging therapy; both PAPF and PTAPF can be considered for definitive soft tissue coverage.

Treatment of infected bone defects with the induced membrane technique

Aims

This study aimed to evaluate the effectiveness of the induced membrane technique for treating infected bone defects, and to explore the factors that might affect patient outcomes.

Methods

A comprehensive search was performed in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases between 1 January 2000 and 31 October 2021. Studies with a minimum sample size of five patients with infected bone defects treated with the induced membrane technique were included. Factors associated with nonunion, infection recurrence, and additional procedures were identified using logistic regression analysis on individual patient data.

Results

After the screening, 44 studies were included with 1,079 patients and 1,083 segments of infected bone defects treated with the induced membrane technique. The mean defect size was 6.8 cm (0.5 to 30). After the index second stage procedure, 85% (797/942) of segments achieved union, and 92% (999/1,083) of segments achieved final healing. The multivariate analysis with data from 296 patients suggested that older age was associated with higher nonunion risk. Patients with external fixation in the second stage had a significantly higher risk of developing nonunion, increasing the need for additional procedures. The autografts harvested from the femur reamer-irrigator-aspirator increased nonunion, infection recurrence, and additional procedure rates.

Conclusion

The induced membrane technique is an effective technique for treating infected bone defects. Internal fixation during the second stage might effectively promote bone healing and reduce additional procedures without increasing infection recurrence. Future studies should standardize individual patient data prospectively to facilitate research on the affected patient outcomes.

Bifunctional Hydrogel-Integrated 3D Printed Scaffold for Repairing Infected Bone Defects

The clinical treatment of infectious bone defects is difficult and time-consuming due to the coexistence of infection and bone defects, and the simultaneous control of infection and repair of bone defects is considered a promising therapy. In this study, a dual-drug delivery scaffold system was fabricated by the combination of a three-dimensional (3D) printed scaffold with hydrogel for infected bone defects repair. The 3D printed polycaprolactone scaffold was incorporated with biodegradable mesoporous silica nanoparticles containing the small molecular drug fingolimod (FTY720) to provide structural support and promote angiogenesis and osteogenesis. The vancomycin (Van)-loaded hydrogel was prepared from aldehyde hyaluronic acid (AHA) and carboxymethyl chitosan (NOCC) by the Schiff base reaction, which can fill the pores of the 3D-printed scaffold to produce a bifunctional composite scaffold. The in vitro results demonstrated that the composite scaffold had Van concentration-dependent antimicrobial properties. Furthermore, the FTY720-loaded composite scaffold demonstrated excellent biocompatibility, vascularization, and osteogenic ability in vitro. In the rat femoral defect model with bacterial infection, the dual-drug composite scaffold showed a better outcome in both infection control and bone regeneration compared to other groups. Therefore, the prepared bifunctional composite scaffold has potential application in the treatment of infected bone defects.

Incidence and risk factors of recurrence in limb osteomyelitis patients after antibiotic-loaded cement spacer for definitive bone defect treatment

Aims

This study was designed to characterize the recurrence incidence and risk factors of antibiotic-loaded cement spacer (ALCS) for definitive bone defect treatment in limb osteomyelitis.

Methods

We included adult patients with limb osteomyelitis who received debridement and ALCS insertion into the bone defect as definitive management between 2013 and 2020 in our clinical centre. The follow-up time was at least two years. Data on patients' demographics, clinical characteristics, and infection recurrence were retrospectively collected and analyzed.

Results

In total, 314 patients with a mean age of 52.1 years (SD 12.1) were enrolled. After a mean of 50 months' (24 to 96) follow-up, 53 (16.9%) patients had infection recurrence including 32 tibiae, ten femora, ten calcanea, and one humerus. Of all patients with recurrence, 30 (9.6%) occurred within one year and 39 (12.4%) within two years. Among them, 41 patients needed reoperation, five received antibiotics treatment only, and seven ultimately required amputations. Following multivariable analysis, we found that patients infected with Gram-negative bacilli were more likely to have a recurrence (odds ratio (OR) 2.38, 95% confidence interval (CI) 1.20 to 6.94; p = 0.046) compared to Staphylococcus aureus; segmental bone defects (OR 5.25, 95% CI 1.80 to 15.26; p = 0.002) and smoking (OR 3.00, 95% CI 1.39 to 6.50; p = 0.005) were also independent risk factors for recurrence after treatment.

Conclusion

Permanent ALCS might be an alternative strategy for definitive bone defect management in selected osteomyelitis cases. However, the overall high recurrence found suggests that it should be cautiously treated. Additionally, segmental defects, Gram-negative infections, and smoking were associated with an increased risk of infection recurrence.

Induced membrane technique combined with a retrograde intramedullary nail for the treatment of infected bone defects of the ankle

In this study, we treated infected ankle bone defects with the induced membrane two-stage technique. The ankle was fused with a retrograde intramedullary nail in the second stage, and the aim of this study was to observe the clinical effect. We retrospectively enrolled patients with infected bone defects of the ankle admitted to our hospital between July 2016 and July 2018. In the first stage, the ankle was temporarily stabilized with a locking plate, and antibiotic bone cement was used to fill the defects after debridement. In the second stage, the plate and cement were removed, the ankle was stabilized with a retrograde nail, and tibiotalar-calcaneal fusion was performed. Then, autologous bone was used to rebuild the defects. The infection control rate, fusion success rate and complications were observed. Fifteen patients were enrolled in the study with an average follow-up of 30 months. Among them, there were 11 males and 4 females. The average bone defect length after debridement was 5.3 cm (2.1-8.7 cm). Finally, 13 patients (86.6%) achieved bone union without recurrence of infection, and 2 patients experienced recurrence after bone grafting. The average ankle-hindfoot function score (AOFAS) increased from 29.75 ± 4.37 to 81.06 ± 4.72 at the last follow-up. The induced membrane technique combined with a retrograde intramedullary nail for the treatment of infected bone defects of the ankle after thorough debridement is an effective treatment method.

Does the use of antibiotic spacer disrupt induced membrane function?

Treatment of large segmental bone defects has been a challenging and long process for both physicians and patients. At present, the induced membrane technique is one of the reconstruction techniques commonly utilized in treating large segmental bone defects. It consists of a two-step procedure. In the first one, after bone debridement, the defect is filled with bone cement. The aim at this stage is to support and protect the defective area with cement. A membrane is formed around the area where cement was inserted 4-6 weeks after the first surgical stage. This membrane secretes vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), as shown in the earliest studies. In the second step, the bone cement is removed, and the defect is filled with cancellous bone autograft. In the first stage, antibiotics can be added to the applied bone cement, depending on the infection. Still, the histological and micromolecular effects of the added antibiotic on the membrane are unknown.This study investigates the molecular and histological effects of antibiotics addition into bone cement on the induced membrane.In this study, conducted on 27 male New Zealand rabbits, the 2 cm long defects of a bone were created in the rabbit femurs. Three groups were formed by placing antibiotic-free, gentamicin, and vancomycin-containing cement in the defect area.These groups were followed for six weeks, and the membrane formed at the end of 6 weeks was examined histologically. As a result of this study, it found that the membrane quality markers (Von Willebrand factor (vwf), Interleukin 6-8 (IL), Transforming growth factor beta (TGF-β), Vascular endothelial growth factor (VEGF) were significantly higher in the antibiotic-free bone cement group. Our study has shown that antibiotics added to the cement have negative effects on the membrane. Based on the results we obtained, it would be a better choice to use antibiotic-free cement in aseptic nonunions. However, more data is needed to understand the effects of these changes on the cement on the membrane.

Functional Approaches in Promoting Vascularization and Angiogenesis in Bone Critical-Sized Defects via Delivery of Cells, Growth Factors, Drugs, and Particles

Critical-sized bone defects, or CSDs, are defined as bone defects that cannot be regenerated by themselves and require surgical intervention via employing specific biomaterials and a certain regenerative strategy. Although a variety of approaches can be used to treat CSDs, poor angiogenesis and vascularization remain an obstacle in these methods. The complex biological healing of bone defects depends directly on the function of blood flow to provide sufficient oxygen and nutrients and the removal of waste products from the defect site. The absence of vascularization can lead to non-union and delayed-union defect development. To overcome this challenge, angiogenic agents can be delivered to the site of injury to stimulate vessel formation. This review begins by introducing the treatment methods for CSDs. The importance of vascularization in CSDs is subsequently highlighted. Delivering angiogenesis agents, including relevant growth factors, cells, drugs, particles, cell secretion substances, their combination, and co-delivery to CSDs are fully explored. Moreover, the effects of such agents on new bone formation, followed by vessel formation in defect areas, are evaluated.

Definitive fixation in the first stage of the induced membrane technique for septic segmental bone defects. Why not?

Background

Infected segmental bone defects (I-SBD) are challenging and complex to manage. This study aimed to show the outcomes achieved in I-SBD of the femur and tibia, treated with the induced membrane technique performing a definitive bone stabilization in the first stage.

Methods

We retrospectively reviewed 30 patients with infected non-articular segmental bone defects of the femur (n = 11) and tibia (n = 19), operated consecutively between January 2015 and May 2021. The need for fixation exchange, bone defect length, allo/autograft ratio used, bone healing, reoperation (discriminating between mechanical and infection-related causes), and failure rates (graft resorption or nonunion) were recorded.

Results

Fixation in the first stage was performed with 28 (93.33%) intramedullary nails, ten coated with antibiotic cement, and 2 (6.67%) locked plates. None were removed during the second stage of the technique. The mean length of the bone defects was 5cm (range 3.5-12). The most commonly used allo-/autograft ratio was 50-50. The bone healing rate was 93.33% (n = 28), with a median follow-up of 7 months (range 3-12). The reoperation rate due to mechanical instability was 3.33% (n = 1) and for recurrence of infection was 10.0% (n = 3). The overall failure rate was 6.67% (n = 2). The median follow-up was 42 months (range 12-85).

Conclusion

Masquelet technique appears feasible and effective in treating infected segmental bone defects of the femur and tibia. Definitive fixation at the first stage showed a success rate of 93.33%, with a re-operation rate of 10.0% related to infection.

Masquelet Technique for the Tibia: A Systematic Review and Meta-Analysis of Contemporary Outcomes

OBJECTIVE

To systematically review outcomes of the Masquelet "induced membrane" technique (MT) in treatment of tibial segmental bone loss and to assess the impact of defect size on union rate when using this procedure.

DATA SOURCES

PubMed, EBSCO, Cochrane, and SCOPUS were searched for English language studies from January 1, 2010, through December 31, 2019.

STUDY SELECTION

Studies describing the MT procedure performed in tibiae of 5 or more adult patients were included. Pseudo-arthrosis, nonhuman, pediatric, technique, nontibial bone defect, and non-English studies were excluded, along with studies with less than 5 patients. Selection adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

DATA EXTRACTION

A total of 30 studies with 643 tibiae were included in this meta-analysis. Two reviewers systematically screened titles or abstracts, followed by full texts, to ensure quality, accuracy, and consensus among authors for inclusion or exclusion criteria of the studies. In case of disagreement, articles were read in full to assess their eligibility by the senior author. Study quality was assessed using previously reported criteria.

DATA SYNTHESIS

Meta-analysis was performed with random-effects models and meta-regression. A meta-analytic estimate of union rate independent of defect size when using the MT in the tibia was 84% (95% CI, 79%-88%). There was no statistically significant association between defect size and union rate ( P = 0.11).

CONCLUSIONS

The MT is an effective method for the treatment of segmental bone loss in the tibia and can be successful even for large defects. Future work is needed to better understand the patient-specific factors most strongly associated with MT success and complications.

LEVEL OF EVIDENCE

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

Outcome of multi-staged induced membrane technique based on post-debridement cultures for the management of critical-sized bone defect following fracture-related infection

The authors' institution utilizes multi-staged induced membrane technique protocol based on post-debridement culture in treating patients with critical-sized bone defect in lower extremity due to infected nonunion or post-traumatic osteomyelitis. This study aimed to evaluate the success rate of this limb reconstruction method and which risk factors are associated with recurrence of infection. 140 patients were treated with multi-staged induced membrane technique from 2013 to 2018 and followed up more than 24 months after bone grafting. The primary success rate of limb reconstruction was 75% with a mean follow-up of 45.3 months. The mean Lower Extremity Functional Scale in success group improved from 12.1 ± 8.5 to 56.6 ± 9.9 after the treatment. There were 35 cases of recurrence of infection at a mean of 18.5 months after bone grafting. Independent risk factors for recurrence of infection were infected free flap, surprise positive culture, deviation from our surgical protocol, and elevated ESR before final bone graft procedure. In conclusion, this study showed that multi-staged induced membrane technique protocol based on post-debridement culture resulted in 75% success rate and revealed a number of risk factors for recurrence of infection.

Is immediate internal fixation safe in induced membrane technique?

OBJECTIVES

This study aimed to evaluate the treatment outcomes of patients treated with induced membrane technique (IMT) for the reconstruction of bone defects and to identify factors associated with the success and failure of the modified technique.

PATIENTS AND METHODS

Between January 2016 and April 2021, a total of 23 adult patients (20 males, 3 females; median age: 39.9 years; range, 20 to 69 years) who underwent bone reconstruction using the IMT for established pseudoarthrosis and acute bone loss were retrospectively analyzed. Fracture type, the size and location of bone defect, the nature of the index injury, the type of fixation, the interval between stages of the operation, and any diagnosis of infection or other complications of the patients were assessed.

RESULTS

The median bone union was achieved in 6.6 (range, 4 to 11) months. The median index of reconstruction was 19 (range, 10 to 30%). The main complications were recurrent infection in two cases and nonunion in one case. Massive graft resorption occurred in two cases.

CONCLUSION

Immediate internal fixation is a reliable and effective method in the treatment of complex bone defects. A large volume of autograft is required for the reconstruction of long defects, which presents as a limiting factor, particularly in patients undergoing previous surgical interventions.

Application of the induced membrane technique of tibia using extracorporeal vs. intracorporeal formation of a cement spacer: a retrospective study

Background

There were two ways of preparing the cement spacer: intracorporeal and extracorporeal formation. This study aimed to investigate the outcomes of extracorporeal vs. intracorporeal formation of a spacer using the induced membrane technique (IMT) for repairing bone defects of the tibia.

Methods

Sixty-eight patients with tibial defects treated with IMT were analyzed retrospectively. According to the mode of bone cement preparation, patients were divided into intracorporeal and extracorporeal groups (36 vs. 32 respectively). All patients were followed up for 12–48 months (average 18.7 months). The time interval between the first and second stages, the time required to remove the spacer, injury of the IM or bone ends, bone healing and infection control, as well as the functional recovery (Johner—Wruhs scoring), were compared.

Results

There was no significant difference in the preoperative data between the two groups (P > 0.05). There was no significant difference in the time interval (12.64 ± 4.41vs. 13.22 ± 4.96 weeks), infection control (26/28 vs. 20/23), bone healing time (7.47 ± 2.13vs. 7.50 ± 2.14 mos), delayed union (2/36 vs. 2/32), nonunion (2/36 vs. 1/32), an excellent or good rate of limb functional recovery (30/36 vs. 26/32) between the intracorporeal and extracorporeal groups (P > 0.05). However, the time required to remove (3.97 ± 2.34 min) was longer and the injury of IM or bone ends (28/36) was greater in the intracorporeal group than those in the extracorporeal group (0.56 ± 0.38 min and 1/32, respectively), showing a significant difference (P < 0.05).

Conclusion

Both approaches were shown to have similar effects on bone defect repair and infection control. However, intracorporeal formation had advantages in terms of additional stability, while extracorporeal formation had advantages in terms of removal. Therefore, the specific method should be selected according to specific clinical needs. We recommended the extracorporeal or the modified extracorporeal formation in most cases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05355-0.

3D Printed Gelatin/Sodium Alginate Hydrogel Scaffolds Doped with Nano-Attapulgite for Bone Tissue Repair

INTRODUCTION

Bone tissue engineering (BTE) is a new strategy for bone defect repair, but the difficulties in the fabrication of scaffolds with personalized structures still limited their clinical applications. The rapid development in three-dimensional (3D) printing endows it capable of controlling the porous structures of scaffolds with high structural complexity and provides flexibility to meet specific needs of bone repair.

METHODS

In this study, sodium alginate (SA)/gelatin (Gel) hydrogel scaffolds doped with different contents of nano-attapulgite were fabricated via 3D printing. The surface microstructure, hydrophilicity and mechanical properties were fully evaluated. Furthermore, mouse bone marrow-derived mesenchymal stem cells (BMSCs) were cultured with the composite hydrogels in vitro, and proliferation and osteoblastic differentiation were assessed. A rabbit tibia plateau defect model was used to evaluate the osteogenic potential of the composite hydrogel in vivo.

RESULTS

When increasing nano-ATP content, the Gel/SA/nano-ATP composite hydrogels showed better mechanical property and printability. Moreover, Gel/SA/nano-ATP composite hydrogels showed excellent bioactivity, and a significant mineralization effect was observed on the surface after being incubated in simulated body fluid (SBF) for 14 days. The Gel/SA/nano-ATP composite hydrogel also showed good biocompatibility and promoted the osteogenesis of BMSCs. Finally, histological analysis demonstrates that the Gel/SA/nano-ATP composite hydrogels could effectively enhance bone regeneration in vivo.

CONCLUSION

These properties render the Gel/SA/nano-ATP composite hydrogel scaffolds an ideal bone tissue engineering material for the repair of bone defects.

Is the bioactivity of induced membranes time dependent?

PURPOSE

The induced membrane technique (IMT) is a two-stage surgical procedure for reconstruction of bone defects. Bone grafting (second stage of IMT) is recommend after 4-8 weeks assuming the highest bioactivity of IMs. However, larger studies concerning the biology and maturation of IMs and a potential time dependency of the bioactivity are missing. Therefore, aim of this study was the time-dependent structural and cellular characterization of cement spacer IMs concomitantly to an analysis of membrane bioactivity.

METHODS

IMs from 60 patients (35-82 years) were obtained at different maturation stages (1-16 weeks). IMs were studied by histology and co-culture with mesenchymal stem cells (MSC). IM lysates were analyzed by ELISA and protein microarray.

RESULTS

Increasing vascularization and fibrosis were found in membranes older than 4 and 7 weeks, respectively. MSC grew out from all membranes and all membranes enhanced proliferation of cultured MSC. Osteocalcin and osteopontin (in membrane lysates or induced in MSC by membrane tissue) were found over all time points without significant differences. In contrast to alkaline phosphatase activity, increasing levels of osteoprotegerin were found in membranes.

CONCLUSION

The histological structure of IMs changes during growth and maturation, however, biologically active MSC and factors related to osteogenesis are found over all time points with minor changes. Thus, membranes older than 8 weeks exert regenerative capacities comparable to the younger ones. The postulated narrow time frame of 4-8 weeks until bone grafting can be questioned and surgeons may choose timing for the second operation more independently and based on other clinical factors.

3D-printed, bioactive ceramic scaffold with rhBMP-2 in treating critical femoral bone defects in rabbits using the induced membrane technique

Although autogenous bone grafts are an optimal filling material for the induced membrane technique, limited availability and complications at the harvest site have created a need for alternative graft materials. We aimed to investigate the effect of an rhBMP-2-coated, 3D-printed, macro/microporous CaO-SiO2 -P2 O5 -B2 O3 bioactive ceramic scaffold in the treatment of critical femoral bone defects in rabbits using the induced membrane technique. A 15-mm segmental bone defect was made in the metadiaphyseal area of the distal femur of 14 rabbits. The defect was filled with polymethylmethacrylate cement and stabilized with a 2.0 mm locking plate. After the membrane matured for 4 weeks, the scaffold was implanted in two randomized groups: Group A (3D-printed bioceramic scaffold) and Group B (3D-printed, bioceramic scaffold with rhBMP-2). Eight weeks after implantation, the radiographic assessment showed that the healing rate of the defect was significantly higher in Group B (7/7, 100%) than in Group A (2/7, 29%). The mean volume of new bone formation around and inside the scaffold doubled in Group B compared to that in Group A. The mean static and dynamic stiffness were significantly higher in Group B. Histological examination revealed newly formed bone in both groups. Extensive cortical bone formation along the scaffold was found in Group B. Successful bone reconstruction in critical-sized bone defects could be obtained using rhBMP-2-coated, 3D-printed, macro/microporous bioactive ceramic scaffolds. This grafting material demonstrated potential as an alternative graft material in the induced membrane technique for reconstructing critical-sized bone defects.

Current opinions on the mechanism, classification, imaging diagnosis and treatment of post-traumatic osteomyelitis

Post-traumatic osteomyelitis (PTO) is a worldwide problem in the field of orthopaedic trauma. So far, there is no ideal treatment or consensus-based gold standard for its management. This paper reviews the representative literature focusing on PTO, mainly from the following four aspects: (1) the pathophysiological mechanism of PTO and the interaction mechanism between bacteria and the body, including fracture stress, different components of internal fixation devices, immune response, occurrence and development mechanisms of inflammation in PTO, as well as the occurrence and development mechanisms of PTO in skeletal system; (2) clinical classification, mainly the etiological classification, histological classification, anatomical classification and the newly proposed new classifications (a brief analysis of their scope and limitations); (3) imaging diagnosis, including non-invasive examination and invasive examination (this paper discusses their advantages and disadvantages respectively, and briefly compares the sensitivity and effectiveness of the current examinations); and (4) strategies, including antibiotic administration, surgical choices and other treatment programs. Based on the above-mentioned four aspects, we try to put forward some noteworthy sections, in order to make the existing opinions more specific.

Clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture

Objective

This study was designed for the first time to analyze clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture.

Methods

This study retrospectively analyzed 220 older patients with infectious bone nonunion after open tibial fracture. There were 110 patients receiving bone transport technology (Group A) and 110 patients receiving membrane induction technique with antibiotic bone cement (Group B).

Results

There were 164 male patients and 56 female patients, with an age range of 65 to 71 years and an average age of 67 ± 1.3 years. Traffic accident, high-fall injury and crush injury account for 45.5, 27.7 and 26.8%, respectively. Age, gender, histories, causes and fracture location had no significant difference between the two groups (P > 0.05 for all). Operation time in the Group A was significantly shorter than that in the Group B (P < 0.05). Linear and positional alignment (70.9 vs. 57.3), American Knee Society knee function score (167.7 ± 14.9 vs. 123.8 ± 15.7), Baird-Jackson ankle function score (89.9 ± 3.5 vs. 78.4 ± 4.9), bone healing index (43.0 ± 2.0 vs. 44.3 ± 3.0) and clinical recovery (8.2 vs. 4.5) of patients in the Group A were significantly better than those in the Group B (P < 0.05 for all). Wound infection in the Group A (7.3%) was significantly less than that in the Group B (16.4%; P < 0.05). There were neither a neurovascular complication nor a recurrence of infection in the two groups.

Conclusion

Bone transport technology achieved better knee and ankle joint function recovery and superior bone healing and clinical efficacy than membrane induction technique with antibiotic bone cement, suggesting that bone transport technique is worthy of extensive promotion to improve clinical condition of older patients with infectious bone nonunion after open tibial fracture.

Effect of Anti-Infective Reconstituted Bone Xenograft Combined with External Fixator on Serum CRP and PCT Levels and Prognosis of Patients with Bone Infection after Lower Extremity Long Bone Trauma

Bone infection is one of the common complications of orthopedic surgery. After bone trauma occurs in the human body, the infection of Staphylococcus aureus and Gram-negative bacteria into the fracture area can lead to double infection of the soft tissue and bone tissue at the fracture site, leading to a variety of complications, mostly in the lower extremities. Bone infection easily causes bone destruction, bone nonunion, and bone defect, seriously affecting the quality of life of patients. The traditional treatment method of bone infection is to control the infection first and then repair the bone graft, but this method has a long course, poor efficacy, and high disability rate. In this study, anti-infective reconstituted bone xenograft (ARBX) combined with external fixation was used to treat patients with posttraumatic bone infections of the long bones of the lower extremities, to explore its efficacy, and to analyze its effects on serum CRP, PCT levels, and prognosis. Our results showed that ARBX combined with the external fixator had a good effect on the treatment of patients with bone infection after lower extremity long bone trauma, which could effectively enhance the repair and functional recovery of the limb bone, significantly alleviate the infection degree of patients, reduce the inflammatory response of the body, and have a good prognosis.

Management of surgical site infection post-open reduction and internal fixation for tibial plateau fractures

AIMS

In contrast to operations performed for other fractures, there is a high incidence rate of surgical site infection (SSI) post-open reduction and internal fixation (ORIF) done for tibial plateau fractures (TPFs). This study investigates the effect of induced membrane technique combined with internal fixation for managing SSI in TPF patients who underwent ORIF.

METHODS

From April 2013 to May 2017, 46 consecutive patients with SSI post-ORIF for TPFs were managed in our centre with an induced membrane technique. Of these, 35 patients were included for this study, with data analyzed in a retrospective manner.

RESULTS

All participants were monitored for a mean of 36 months (24 to 62). None were subjected to amputations. A total of 21 patients underwent two-stage surgeries (Group A), with 14 patients who did not receive second-stage surgery (Group B). Group A did not experience infection recurrence, and no implant or cement spacer loosening was noted in Group B for at least 24 months of follow-up. No significant difference was noted in the Lower Extremity Functional Scale (LEFS) and the Hospital for Special Surgery Knee Score (HSS) between the two groups. The clinical healing time was significantly shorter in Group B (p＜0.001). Those with longer duration of infection had poorer functional status (p＜0.001).

CONCLUSION

Management of SSI post-ORIF for TPF with induced membrane technique combined with internal fixation represents a feasible mode of treatment with satisfactory outcomes in terms of infection control and functional recovery. Cite this article: Bone Joint Res 2021;10(7):380-387.

Biodegradable magnesium combined with distraction osteogenesis synergistically stimulates bone tissue regeneration via CGRP-FAK-VEGF signaling axis

Critical size bone defects are frequently caused by accidental trauma, oncologic surgery, and infection. Distraction osteogenesis (DO) is a useful technique to promote the repair of critical size bone defects. However, DO is usually a lengthy treatment, therefore accompanied with increased risks of complications such as infections and delayed union. Here, we demonstrated that magnesium (Mg) nail implantation into the marrow cavity degraded gradually accompanied with about 4-fold increase of new bone formation and over 5-fold of new vessel formation as compared with DO alone group in the 5 mm femoral segmental defect rat model at 2 weeks after distraction. Mg nail upregulated the expression of calcitonin gene-related peptide (CGRP) in the new bone as compared with the DO alone group. We further revealed that blockade of the sensory nerve by overdose capsaicin blunted Mg nail enhanced critical size bone defect repair during the DO process. CGRP concentration-dependently promoted endothelial cell migration and tube formation. Meanwhile, CGRP promoted the phosphorylation of focal adhesion kinase (FAK) at Y397 site and elevated the expression of vascular endothelial growth factor A (VEGFA). Moreover, inhibitor/antagonist of CGRP receptor, FAK, and VEGF receptor blocked the Mg nail stimulated vessel and bone formation. We revealed, for the first time, a CGRP-FAK-VEGF signaling axis linking sensory nerve and endothelial cells, which may be the main mechanism underlying Mg-enhanced critical size bone defect repair when combined with DO, suggesting a great potential of Mg implants in reducing DO treatment time for clinical applications.

Three-dimensional-printed individualized porous implants: A new "implant-bone" interface fusion concept for large bone defect treatment

Bone defect repairs are based on bone graft fusion or replacement. Current large bone defect treatments are inadequate and lack of reliable technology. Therefore, we aimed to investigate a simple technique using three-dimensional (3D)-printed individualized porous implants without any bone grafts, osteoinductive agents, or surface biofunctionalization to treat large bone defects, and systematically study its long-term therapeutic effects and osseointegration characteristics. Twenty-six patients with large bone defects caused by tumor, infection, or trauma received treatment with individualized porous implants; among them, three typical cases underwent a detailed study. Additionally, a large segmental femur defect sheep model was used to study the osseointegration characteristics. Immediate and long-term biomechanical stability was achieved, and the animal study revealed that the bone grew into the pores with gradual remodeling, resulting in a long-term mechanically stable implant-bone complex. Advantages of 3D-printed microporous implants for the repair of bone defects included 1) that the stabilization devices were immediately designed and constructed to achieve early postoperative mobility, and 2) that osseointegration between the host bone and implants was achieved without bone grafting. Our osseointegration method, in which the “implant-bone” interface fusion concept was used instead of “bone-bone” fusion, subverts the traditional idea of osseointegration.

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A new “implant-bone” interface fusion concept for large bone defect treatment was realized using 3D-printed porous implants.

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Osseointegration was achieved without bone grafting.

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An animal study revealed that the bone grew into the pores with gradual remodeling.

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Immediate and long-term biomechanical stability was achieved by this method.

Comparison of amniotic membrane versus the induced membrane for bone regeneration in long bone segmental defects using calcium phosphate cement loaded with BMP-2

Thanks to its biological properties, the human amniotic membrane (HAM) combined with a bone substitute could be a single-step surgical alternative to the two-step Masquelet induced membrane (IM) technique for regeneration of critical bone defects. However, no study has directly compared these two membranes. We first designed a 3D-printed scaffold using calcium phosphate cement (CPC). We assessed its suitability in vitro to support human bone marrow mesenchymal stromal cells (hBMSCs) attachment and osteodifferentiation. We then performed a rat femoral critical size defect to compare the two-step IM technique with a single-step approach using the HAM. Five conditions were compared. Group 1 was left empty. Group 2 received the CPC scaffold loaded with rh-BMP2 (CPC/BMP2). Group 3 and 4 received the CPC/BMP2 scaffold covered with lyophilized or decellularized/lyophilized HAM. Group 5 underwent a two- step induced membrane procedure with insertion of a polymethylmethacrylate (PMMA) spacer followed by, after 4 weeks, its replacement with the CPC/BMP2 scaffold wrapped in the IM. Micro-CT and histomorphometric analysis were performed after six weeks. Results showed that the CPC scaffold supported the proliferation and osteodifferentiation of hBMSCs in vitro. In vivo, the CPC/BMP2 scaffold very efficiently induced bone formation and led to satisfactory healing of the femoral defect, in a single-step, without autograft or the need for any membrane covering. In this study, there was no difference between the two-step induced membrane procedure and a single step approach. However, the results indicated that none of the tested membranes further enhanced bone healing compared to the CPC/BMP2 group.

Radiological and clinical outcomes using induced membrane technique combined with bone marrow concentrate in the treatment of chronic osteomyelitis of immature patients

Aims

Treatment of chronic osteomyelitis (COM) for young patients remains a challenge. Large bone deficiencies secondary to COM can be treated using induced membrane technique (IMT). However, it is unclear which type of bone graft is optimal. The goal of the study was to determine the clinical effectiveness of bone marrow concentrator modified allograft (BMCA) versus bone marrow aspirate mixed allograft (BMAA) for children with COM of long bones.

Methods

Between January 2013 and December 2017, 26 young patients with COM were enrolled. Different bone grafts were applied to repair bone defects secondary to IMT procedure for infection eradication. Group BMCA was administered BMCA while Group BMAA was given BMAA. The results of this case-control study were retrospectively analyzed.

Results

Patient infection in both groups was eradicated after IMT surgery. As for reconstruction surgery, no substantial changes in the operative period (p = 0.852), intraoperative blood loss (p = 0.573), or length of hospital stay (p = 0.362) were found between the two groups. All patients were monitored for 12 to 60 months. The median time to bone healing was 4.0 months (interquartile range (IQR) 3.0 to 5.0; range 3 to 7) and 5.0 months (IQR 4.0 to 7.0; range 3 to 10) in Groups BMCA and BMAA, respectively. The time to heal in Group BMCA versus Group BMAA was substantially lower (p = 0.024).

Conclusion

IMT with BMCA or BMAA may attain healing in large bone defects secondary to COM in children. The bone healing time was significantly shorter for BMCA, indicating that this could be considered as a new strategy for bone defect after COM treatment.

Cite this article: Bone Joint Res 2021;10(1):31–40.

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

PURPOSE

This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018.

METHODS

A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

RESULTS

Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6-80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1-624) and mean follow-up 51 months (range 6-126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79-87) of all cases, increasing to 94% (95% CI 92-96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6-11) and amputation in 3% (95% CI 2-3). Final outcomes overlapped across treatment strategies.

CONCLUSION

Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies.

Clinicoradiological outcomes following single-stage treatment using external fixator, copious bone grafting and high dose antibiotics for infected postosteomyelitic nonunion of femoral shaft

We aimed to study clinical and radiological outcomes following a 'single-stage protocol' in postosteomyelitic-infected nonunion of the femur in children. The report is based on a retrospective chart review (2010-2018) of 10 children below 12 years of age presenting with nonunion following a pathological fracture after osteomyelitis of hematogenous origin treated with above-mentioned operative modality. All patients were grade A (normal host) on the basis of the physiological classification. Patients with posttraumatic or surgical osteomyelitis were excluded. All patients were treated with a combination of debridement of dead bone and necrotic tissues, acute bone docking, use of external fixator and addition of copious nonvascularized autogenous bone graft obtained from fibula/tibia. The postsurgical period was covered by high dose broad spectrum antibiotics for 6 weeks. At follow up, union, infection, deformity, leg-length discrepancy, motion of hip and knee and ability to perform unaided walking was recorded. Mean age for studied patients (five males and five females) was 6.6 years. Average time elapsed since pathological fracture was 7.7 months (range: 3-15 months). MRSA and MSSA were cultured in three and four patients, respectively. Union occurred in all patients with average time of 3.7 months and total follow up being 2.9 years (range: 1-7 years). There was persistence of deep infection despite union in three patients. Average limb shortening was 4.3 cm (range: 2-7 cm). The knee motion was severely restricted (≤30°) in three patients. According to Paley's criteria, there were 2 excellent, 4 good, 2 fair and 2 poor results. Single-stage protocol as described above is a usable option for postosteomyelitic femoral nonunions in children. Union occurred in all cases. Healing occurred in three patients despite the persistence of infection. The restriction of range of motion at knee and limb length discrepancy was main complication encountered with this procedure.

Functional outcome and complications after treatment of comminuted tibial fractures or deformities using Ilizarov bone transport: a single-center study at 15- to 30-year follow-up

INTRODUCTION

The aim of this retrospective study was to evaluate long-term outcomes and complications of a single-center and single-surgeon patient series of isolated and comminuted tibial fractures with bone defects or tibial deformities treated by Ilizarov bone transport.

MATERIALS AND METHODS

Data from a consecutive series of patients with isolated comminuted tibial fractures (Fracture Group: FG) or deformities (Deformity Group: DG) treated between 1987 and 2002 were included. For clinical assessment, the Lower Extremities Functional Scale was used; complications were recorded according to the Dindo classification and statistical analysis was performed.

RESULTS

Overall, 72 patients were enrolled with a mean follow-up of 21.6 years (range 15-30) a mean LEFS of 36.4 (range 0-100). In the FG, the mean LEFS was 21.3 (range 0-98.75), and the external fixation time (EFT) lasted 7.6 months (range 3-18 months) months. In the DG, the mean LEFS was 76.7 (range 55-100), and the EFT was 10.6 months (range 3-20 months). Between the two groups, the clinical evaluation was significantly different, while the EFT was not (p = 0.14). In the FG, the worst results were obtained in the cases of open fractures with a higher percentage of complications and the need for further surgical procedures. The cumulative rate of complications was 55.6% during the first 36 months and 66.7% at the minimum follow-up of 180 months.

CONCLUSIONS

Ilizarov bone transport, even at a long follow-up period, proved to be an effective technique for both definitive treatment of comminuted tibial fractures with bone defects or tibial deformities. Although our functional outcomes were lower in patients with exposed fractures, they were in line with the literature, but not influenced by the EFT when properly managed. Most complications occurred during the first 3 years; however, they could also arise much later, even until almost 30 years.

The induced membrane technique for the management of long bone defects

AIMS

The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT.

METHODS

A systematic search was performed in CINAHL, The Cochrane Library, Embase, Ovid MEDLINE, and PubMed. We included articles from 1 January 1980 to 30 September 2019. Studies with a minimum sample size of five cases, where the IMT was performed primarily in adult patients (≥ 18 years old), in a long bone were included. Multivariate regression models were performed on patient-level data to determine variables associated with nonunion, postoperative infection, and the need for additional procedures.

RESULTS

A total of 48 studies were included, with 1,386 cases treated with the IMT. Patients had a mean age of 40.7 years (4 to 88), and the mean defect size was 5.9 cm (0.5 to 26). In total, 82.3% of cases achieved union after the index second stage procedure. The mean time to union was 6.6 months (1.4 to 58.7) after the second stage. Our multivariate analysis of 450 individual patients showed that the odds of developing a nonunion were significantly increased in those with preoperative infection. Patients with tibial defects, and those with larger defects, were at significantly higher odds of developing a postoperative infection. Our analysis also demonstrated a trend towards the inclusion of antibiotics in the cement spacer having a protective effect against the need for additional procedures.

CONCLUSION

The IMT is an effective management strategy for complex segmental bone defects. Standardized reporting of individual patient data or larger prospective trials is required to determine the optimal implementation of this technique. This is the most comprehensive review of the IMT, and the first to compile individual patient data and use regression models to determine predictors of outcomes. Cite this article: Bone Joint J 2020;102-B(12):1723-1734.

Treatment of posttraumatic patella osteomyelitis with MRSA infection and knee stiffness: a case report

BACKGROUND

Posttraumatic patella osteomyelitis is rare, and the treatment of osteomyelitis remains to be challenging. Control of the infection commonly costs a long time, and it is easily to cause knee stiffness. In addition, there is no unified protocol for the treatment of knee stiffness.

CASE PRESENTATION

We reported a case of posttraumatic patella osteomyelitis that successive infected with methicillin-resistant staphylococcus aureus (MRSA) after multiple surgeries. We successfully treated osteomyelitis by one-staged surgery, but the patient present knee stiffness after treatment. Thus Ilizarov external fixation system was further used to gradually adjust the mobility by exerting mechanical stress to the joint. After adjusting the frame under a scheduled plan, the patient successfully restored satisfactory knee function.

CONCLUSIONS

Adequate debridement is the key to control infections of posttraumatic osteomyelitis. Control the infection of posttraumatic patella osteomyelitis by one-staged surgery is achievable and could shorten the knee immobilization period. When knee stiffness occurs, scheduled range of motion (ROM) adjustment using Ilizarov frame with hinges might be a safe and useful method to restore function.

What is the optimal timing for bone grafting during staged management of infected non-unions of the tibia? A systematic review and best evidence synthesis

PURPOSE

To summarize the best available evidence with regards to timing of staged bone grafting for infected tibial non-union, and to extract evidence-based criteria indicating when bone grafting can be safely performed.

METHODS

Medline, Embase, Scopus, and Google Scholar were searched, and publications of evidence Level I-IV from 2000 to 2020 were included. Risk of bias was assessed with the Cochrane Collaboration's Risk of Bias Tool and ROBINS-I tool. Study quality was assessed with the GRADE system, Coleman methodology score, and Methodological Index for Non-Randomized Studies (MINORS). Heterogeneity was assessed with the I² statistic. A forest plot was used to pool the timing of bone grafting for all included studies. For data synthesis and analysis, a best evidence synthesis was used.

RESULTS

A total of 15 studies were included (353 cases). Risk of bias was high in 8 studies and the quality for 14 studies was assessed as very low, with a mean Coleman score of 33.5 and a mean MINORS score of 7.9. The mean time from the index surgery to bone grafting was 7.03 weeks ranging from 2 to 15 weeks (lower limit 6 weeks, upper limit 8.07 weeks). Best evidence analysis demonstrated that 8 of the 15 studies (53%) with 237 cases (67%) performed staged bone grafting inside this window. Union was achieved in 92%.

CONCLUSION

The results of this best evidence systematic review suggest that, for most infected tibial non-unions, secondary bone grafting can be successfully performed between 6-8 weeks with expected union rates over 90%.

Induced Membrane Technique (Masquelet) for Bone Defects in the Distal Tibia, Foot, and Ankle: Systematic Review, Case Presentations, Tips, and Techniques

Bone defects to the distal tibia, foot, and ankle can be challenging to reconstruct. The induced membrane (Masquelet) technique has become an established method of repair for challenging areas of bone loss. It has been applied in acute open fractures, chronic nonunion, osteomyelitis, and gout erosion. This article presents a systematic review of distal tibia, foot, and ankle results using the Masquelet procedure, which should be considered in cases of challenging critical bone loss. Further work is needed to present large studies of the procedure on foot and ankle patients to consolidate current knowledge.

Induced membrane technique: a critical literature analysis and proposal for a failure classification scheme

The reconstruction of long-bone segmental defects remains challenging, with the three common methods of treatment being bone transport, vascularized bone transfer, and the induced membrane technique (IMT). Because of its simplicity, replicability, and reliability, usage of IMT has spread all over the world in the last decade, with more than 300 papers published in the PubMed literature database on this subject so far. Most of the clinical studies have reported high rates of bone union, yet some also include more controversial results with frequent complications and revision surgeries. At the same time, various experimental research efforts have been designed to understand and improve the biological properties of the induced membrane. This literature review aims to provide an overview of IMT clinical results in terms of bone union and complications and to compare them with those of other reconstructive procedures. In light of our findings, we then propose an original classification scheme of IMT failures distinguishing between preventable and nonpreventable failures.

Bone reconstruction by the induced membrane technique. What differences between conventional and ballistic trauma?

BACKGROUND

The induced membrane technique (IMT) has been widely evaluated for reconstruction of post-traumatic bone defects. However, no specific evaluation was conducted in ballistic injuries. The objective of the present study was to compare IMT in conventional trauma (CT) versus ballistic trauma (BT) managed in a military trauma center.

METHODS

A retrospective study was conducted between 2009 and 2018 in patients treated by IMT for post-traumatic bone defects, whatever the defect location. Endpoints comprised bone union, residual infection, additional bone grafting and lower-limb amputation.

RESULTS

Thirty-six patients were included: 24 in the CT and 12 in the BT group. Demographics and injury pattern were similar in both groups, with open fracture and infected lesions predominating. The only significant difference was that tibial bone defects were larger in the BT group. Operative parameters and results were also similar. At a mean 24 months' follow-up, bone union rate was 83% in both groups, without significant differences in residual infection, complementary grafting or late amputation.

CONCLUSION

IMT is appropriate to bone reconstruction in the aftermath of ballistic trauma, with similar results to those obtained in conventional trauma.

LEVEL OF EVIDENCE

IV, retrospective study.

Efficacy comparison of double-level and single-level bone transport with Orthofix fixator for treatment of tibia fracture with massive bone defects

PURPOSE

The aim of this study was to evaluate the clinical and functional outcomes of patients with large post-traumatic tibial bone defects managed by double-level bone transport using the Ilizarov technique and compare it with one-level bone transport technique.

METHODS

A retrospective cohort study was conducted on 26 patients with open tibial fracture from January 2010 to January 2017. All cases were Gustilo III. Depending on the site of osteotomy, the patients were divided into single-level (n = 13) and double-level groups (n = 13). The bone transport time, consolidation time of the distraction gap, docking site healing time, external fixation time, external fixation index, soft tissue defect area, soft tissue growth index, operating time, and surgical bleeding volume were recorded and compared between the two groups. Bone and functional results were evaluated according to the Association for the Study and Application of the Method of Ilizarov (ASAMI) criteria.

RESULTS

The mean duration of follow-up was 28.5 ± 5.8 months (range 13-38 months) since the Orthofix fixator was removed, all patients achieved complete union in the docking site and consolidation in the regenerate bone; moreover, the wound was closed The mean bone defect length after debridement was 7.2 cm (range 5.8-9.0 cm) in single-level group vs. 10.7 cm (range 7.5-15.0 cm) in the double-level group (P < 0.05). The mean docking site healing time was 10.85 ± 1.52 months in the single-level group vs. 8.93 ± 2.29 months in the double-level group (P < 0.05); external frame time was 18.06 months (range 15-20 months) in single-level group vs. 12.71 months (range 9.5-16.0 months) in the double-level group (P < 0.05); external fixation index was 2.52 months/cm (range 2.15-2.94 months/cm) versus 1.22 months/cm (range 0.96-1.67 months/cm) in double-level group (P < 0.01); and soft tissue growth index was 0.29 months/cm² (range 0.21-0.45 months/cm²) in the single-level group versus 0.62 months/cm² (range 0.47-0.86 months/cm²) in the double-level group (P < 0.01). According to the ASAMI classification, the clinical and functional results in the double-level group were better than in the single-level group.

CONCLUSION

The Ilizarov technique of double-level bone transport with Orthofix external fixator can be used successfully to repair and reconstruct the tibial bone loss and accompanying soft tissue defect.

Risk factors associated with recurrence of extremity osteomyelitis treated with the induced membrane technique

INTRODUCTION

Our aim was to observe the efficacy of the induced membrane technique in the treatment of extremity osteomyelitis and to analyse the causes of infection recurrence and its risk factors.

METHODS

We retrospectively analysed 424 cases of extremity osteomyelitis treated with the induced membrane technique in our department between May 2013 and June 2017. Infection recurrence time, recurrence sites and other relevant information were collected, summarized, and analysed.

RESULTS

A total of 424 patients were considered as "cured" of osteomyelitis after the first stage and the induced membrane technique was performed to rebuild the bone defects. After a mean follow-up of 31.6 (16-63) months, 52 patients had recurrence of infection, including 42 tibias and 10 femurs. The recurrence rate was 12.26%. Symptoms were relieved in 16 patients after intravenous antibiotic treatment. In the remaining 36 cases (8.49%), the infection was uncontrolled by intravenous antibiotics and surgical debridement was performed. The recurrence rate of infection of the tibia (16.22%) was higher than that of the femur (8.70%). The recurrence rate of post-traumatic osteomyelitis (14.66%) was significantly higher than that of hematogenous osteomyelitis (2.41%). Patients in whom Pseudomonas aeruginosa was isolated at the first stage had a recurrence rate of 28% (7/25), which was higher than that with the other isolated bacteria. Logistic regression analysis showed that repeated operations (≥3), post-traumatic osteomyelitis, and internal fixation at the first stage were risk factors for recurrence of infection, with odds ratios (ORs) of 2.30, 5.53 and 5.28 respectively.

CONCLUSIONS

The induced membrane technique is an effective method in the treatment of extremity osteomyelitis, although infection recurs in some cases. Repeated operations, post-traumatic osteomyelitis, and internal fixation at the first stage were risk factors for recurrence of infection. P. aeruginosa isolated at the first stage, tibia osteomyelitis, the presence of sinus, or flaps may also be associated with recurrence of infection.

Similarities and Differences of Induced Membrane Technique Versus Wrap Bone Graft Technique

BACKGROUND

There are no reports on the similarities and differences between induced membrane (IM) technique and wrap bone graft(WBG) technique.

OBJECTIVE

The aims of this study are to investigate the effects of IM technique and WBR technique in repairing segmental bone defects, and to analyze the similarities and differences between them.

MATERIALS AND METHODS

66 patients of tibial segmental bone defects treated by IM technique and WBG technique were retrospectively analyzed. Aged 13-69 years old with an average of 35.3 years old. IM technique was divided into early IM group (bone grafting at 6-8 weeks of bone cement filling) and late IM group (bone grafting after 8 weeks of bone cement filling). WBG was divided into titanium mesh group and line suturing cortical bone blocks group. There were 11 cases, 25 cases, 10 cases and 20 cases in the early IM group, late IM group, titanium mesh group and line suturing group, respectively. Bone healing, complications and functional recovery (Paley's method) were observed, the causes of nonunion and delayed union and factors affecting bone healing were analyzed.

RESULTS

There were no significant differences in terms of age, sex, defect length, course, fixation method, defect location and preoperative function of adjacent joints among the 4 groups. All patients were followed up for 12-50 months, with an average of 20.1 months. The clinical healing time of early IM group, late IM group, titanium mesh group and line suturing group were (5.81 ± 0.75) months, (7.56 ± 1.66) months, (7.50 ± 0.70) months and (7.81 ± 1.81) months, respectively, showing significant differences among the 4 groups (P = 0.005). However, only early IM group had significant difference with other groups (P < 0.05), while no significance was found between late IM group and WBR group, between titanium mesh group and suture group (P > 0.05). There were no significant differences in healing ration, complications and functional recovery of adjacent joints among the 4 groups (P > 0.05). There were 4 cases of nonunion and delayed union, all of which were caused by poor quantity or quality of bone graft or unstable bone graft or internal fixation.

CONCLUSION

Both IM technique and WBG technique are effective method for repairing segmental bone defects. In addition to mechanical encapsulation, early IM has biological osteogenesis. However, mechanical encapsulation is a common basis for repairing bone defects, and biological osteogenesis can enhance bone healing.

Evidence-Based Recommendations for Local Antimicrobial Strategies and Dead Space Management in Fracture-Related Infection

Fracture-related infection (FRI) remains a challenging complication that imposes a heavy burden on orthopaedic trauma patients. The surgical management eradicates the local infectious focus and if necessary facilitates bone healing. Treatment success is associated with debridement of all dead and poorly vascularized tissue. However, debridement is often associated with the formation of a dead space, which provides an ideal environment for bacteria and is a potential site for recurrent infection. Dead space management is therefore of critical importance. For this reason, the use of locally delivered antimicrobials has gained attention not only for local antimicrobial activity but also for dead space management. Local antimicrobial therapy has been widely studied in periprosthetic joint infection, without addressing the specific problems of FRI. Furthermore, the literature presents a wide array of methods and guidelines with respect to the use of local antimicrobials. The present review describes the scientific evidence related to dead space management with a focus on the currently available local antimicrobial strategies in the management of FRI. LEVEL OF EVIDENCE:: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Modified Capanna's Technique (Vascularized Free Fibula Combined with Allograft) as a Single-Stage Procedure in Post-traumatic Long-Segment Defects of the Lower End of the Femur: Outcome Analysis of a Series of 19 Patients with an Average Gap of 14 cm

Objectives  Salvage and reconstruction of posttraumatic defects of the long bone are complex due to the multiple procedures involved and increased chances of poor outcomes. We present the outcomes of the modified Capanna’s technique—a reliable single-stage procedure of combining allograft and free vascularized fibular graft—in treating large posttraumatic bone defects in the distal third of the femur.

Study Design  This is a retrospective analysis.

Materials and Methods  Between April 2012 and September 2016, 19 patients with an average age of 33.8 years (range: 18–49 years) and an average defect of 14.5 cm (range: 9.5–20 cm) in the distal femur were managed by the modified Capanna’s technique. Bone union time and functional outcome using lower extremity functional score (LEFS) after union were noted.

Outcomes and Results  Eighteen grafts went onto achieve bony union at an average of 6.6 months (range: 5–9), with an average knee flexion of 80 degrees (range: 45–110 degrees) and an average LEFS of 63 (range: 46–72). One patient had a nonunion with graft resorption at 8 months following persistent infection and was revised with debridement and augmenting the vascularized fibula from the other leg which went on to achieve union. Three patients had superficial infection, and three patients had delayed union.

Conclusion  The modified Capanna’s technique provided increased biology and enhanced structural stability and therefore is a good single-stage procedure in the reconstruction of posttraumatic long-segment defects of the distal femur.

Level of Evidence  Level 4.

Level of Clinical Care  Level I tertiary trauma center.

Investigating clinical characteristics and prognostic factors in patients with chronic osteomyelitis of humerus

Background

Chronic osteomyelitis in the humerus, which has complex neuroanatomy and a good soft tissue envelope, represents a unique clinical challenge. However, there are relatively few related studies in the literature. This article retrospectively reviewed a large case series with the aims of sharing our management experiences and further determining factors associated with the outcomes.

Methods

Twenty-eight consecutive adult patients with a mean age of 36 years were identified by reviewing the osteomyelitis database of our clinic centre. The database was used to prospectively identify all osteomyelitis cases between 2013 and 2017, and all data then was retrospectively analysed.

Results

The mean follow-up period was 35 months (range 24–60). The aetiology was trauma in 43% (12) of the patients and haematogenous in 57% (16) of the patients, and Staphylococcus aureus was a solitary agent in 50% (14) of the patients. Host-type (Cierny’s classification) was IA in 8, IIIB in 11 and IVB in 9 patients. All patients required debridement followed by the placement of a temporary antibiotic-impregnated cement spacer (rod). Seventeen patients received a cement-coated plate for internal fixation after debridement, and 13 patients needed bone grafts when the spacer was staged removed. All patients attained an infection-free bone healing state at the final follow-up. The final average DASH (disabilities of the arm, shoulder and hand) score was 18.14 ± 5.39, while 6 patients (two developed traumatic olecranarthritis, four developed radial nerve injuries) showed the lowest levels of limb function (p = 0.000) and were unemployed. Three patients (type I; significant difference between type I versus type III and type IV patients, p < 0.05) experienced recurrence after debridement and underwent a second revision, which was not related to the bone graft (p = 0.226) or plate fixation (p = 0.050).

Conclusions

Humeral chronic osteomyelitis can be treated with general surgery and anti-infective therapy; medullary (type I) infection presents a challenge, and the antibiotic-coated cement plate provides favourable fixation without increasing recurrence of infections. Clinicians should be aware of potential iatrogenic nerve injuries when treating these patients with complicated cases, and an experienced surgeon may improve the outcome.

Unexpected synergistic and antagonistic antibiotic activity against Staphylococcus biofilms

Objectives

To evaluate putative anti-staphylococcal biofilm antibiotic combinations used in the management of periprosthetic joint infections (PJIs).

Methods

Using the dissolvable bead biofilm assay, the minimum biofilm eradication concentration (MBEC) was determined for the most commonly used antimicrobial agents and combination regimens against staphylococcal PJIs. The established fractional inhibitory concentration (FIC) index was modified to create the fractional biofilm eradication concentration (FBEC) index to evaluate synergism or antagonism between antibiotics.

Results

Only gentamicin (MBEC 64 mg/L) and daptomycin (MBEC 64 mg/L) were observed to be effective antistaphylococcal agents at clinically achievable concentrations. Supplementation of gentamicin with daptomycin, vancomycin or ciprofloxacin resulted in a similar or lower MBEC than gentamicin alone (FBEC index 0.25-2). Conversely, when rifampicin, clindamycin or linezolid was added to gentamicin, there was an increase in the MBEC of gentamicin relative to its use as a monotherapy (FBEC index 8-32).

Conclusions

This study found that gentamicin and daptomycin were the only effective single-agent antibiotics against established Staphylococcus biofilms. Interestingly the addition of a bacteriostatic antibiotic was found to antagonize the ability of gentamicin to eradicate Staphylococcus biofilms.

Effects of Vacuum Sealing Drainage Combined with Ilizarov Bone Transport Technique in the Treatment of Tibial Traumatic Osteomyelitis

Background

The aim of this study was to analyze the efficacy of vacuum sealing drainage combined with Ilizarov bone transport technique in the treatment of tibial traumatic osteomyelitis and risk factors for postoperative pin infection.

Material/Methods

We enrolled 78 patients with tibial traumatic osteomyelitis admitted at the First People’s Hospital of Kashgar from January 2015 to September 2017 and treated with vacuum sealing drainage combined with Ilizarov bone transport technique.

Results

After combined treatment, SAS and SDS scores decreased significantly, while SF-36 scores increased significantly. Comparisons showed that there were significant differences in the scores of patients after treatment (P<0.05). Univariate analysis showed that there were no significant differences in gender, BMI, hypertension, diabetes mellitus, COPD, smoking index, alcohol abuse history, or residence (P>0.05). There were significant differences in age, fracture type, fixation type, pin loosening, and indwelling time between the 2 groups (P<0.05). Multivariate logistic analysis showed that age, fracture type, fixation type, pin loosening, and indwelling time were independent risk factors for pin infection. Age, fracture type, fixation type, pin loosening, and indwelling time are independent risk factors for pin infection in patients with tibial traumatic osteomyelitis.

Conclusions

Combination of vacuum sealing drainage with Ilizarov bone transport technique can effectively improve the condition of tibial traumatic osteomyelitis, improve the quality of life of patients, and reduce the occurrence of adverse emotions of patients. Age, fracture type, fixation type, pin loosening, and indwelling time are independent risk factors for pin infection in patients with tibial traumatic osteomyelitis.

Use of Masquelet technique in treatment of septic and atrophic fracture nonunion

BACKGROUND

Treatment of atrophic non-unions and large bone defects or infections remains a challenging task for the treating surgeon. In the herein study, we present our experience of the 'Masquelet technique' according to the 'diamond concept' for the treatment of complex long bone reconstruction procedures.

METHODS

Between February 2010 and March 2015, 150 patients (mean age 51.4) with atrophic and- /or infected non-unions were included in this prospective study. All patients received autologous bone graft, a graft expander (TCP (tricalcium phosphate)) and BMP (bone morphogenic protein). Clinical and radiological parameters were assessed at 6 weeks, and at 3, 6 and 12 months. The SF-12 questionnaire was used to evaluate the subjective health of patients.

RESULTS

A successful bony consolidation of the non-unions was observed in 120 (80%) cases with a median healing time of 12.1 months. The mean defect gap was 4.4cm. Initial infection was documented in 54 cases. The most frequently identified pathogen was staphylococcus epidermidis and staphylococcus aureus. A successful removal of microorganisms with subsequent healing was achieved in 39 cases (72%). The SF-12 scores of subjective physical and mental health increased from PCS 31.5 preoperatively to 36.7 one year postoperatively, while MCS increased from 45.5 to 48.7.

CONCLUSIONS

Our study showed that the Masquelet technique according to the 'diamond concept' is a valid method to treat complex atrophic non-unions with large bone defects and associated infection. Following the principles of the 'diamond concept' (targeted optimization of tissue engineering and bone regeneration) a high rate of success can be expected in these difficult reconstruction cases.