The Induced Membrane Technique for the Management of Segmental Tibial Defect or Nonunion: A Systematic Review and Meta-Analysis

Clinical outcome of chronic haematogenous osteomyelitis of the femur or tibia in adults using selective segmental osteotomy and induced membrane technique

Identification of infected lesions in chronic haematogenous osteomyelitis (CHOM) is challenging due to no distinct boundary. The optimal methods of debridement and bone reconstruction remain controversial. The aim of this study was to evaluate the clinical efficacy of selective segmental osteotomy with induced membrane technique in adult CHOM patients of the femur or tibia. The patients who underwent a staged surgery of induced membrane technique were include. In the first stage. the patients were treated by selective segmental osteotomy for debridement according to imaging result preoperatively. In the second stage, spacer removing, fixation and bone grafting were performed sequentially. 16 patients were included. The mean age was 34.7 years. After debridement, the mean bone defects length was 7.9 cm. At a mean followed-up of 30.5 months, no infection recurrence in all patients. At the last follow-up, all patients achieved bone union on average at 6.9 months. Visual Analogue Scale (VAS) score, Self-rated Anxiety Scale (SAS) score, and Hospital for Special Surgery (HSS) score improved at 3 months after the second stage of surgery and at the final follow-up compared with initial admission (P < 0.05). For adult patients with CHOM of femur and tibia, selective segmental osteotomy with induced membrane technique is a feasible and effective treatment method.

Custom-Made 3D-Printed Titanium Implants for Managing Segmental Distal Tibial Bone Defects: A Systematic Literature Review

Background: The management of diaphyseal and distal tibial defects and non-unions is a significant challenge. Traditional treatments, such as distraction osteogenesis or Masquelet, are characterized by extended treatment times and elevated complication rates. Innovative approaches, such as customized 3D-printed titanium implants, are often required to restore structural integrity and function. This systematic review aimed to analyze the results achieved to date with this technique. Methods: A systematic review of the literature written in English was performed in PubMed, Scopus, and Cochrane to identify all cases of tibial non-unions or defects treated with customized 3D-printed titanium implants, excluding defects from tumor resection. Studies with a minimum of 12 months of follow-up were included. Results: The causes of treatment were infection in 10 patients, non-union in 6 patients, and severe bone loss after trauma in 3 cases. The size of the defect ranged from 3 to 8.5 cm. Osteointegration was 100% in all studies. The mean time to union was 5.3 months. The complication rate was 16%. Conclusions: Good results were reported in most patients. However, the data are insufficient to define the role of customized 3D-printed implants compared to traditional techniques. Further studies comparing them are needed to draw explicit guidelines.

Surgical nonunion treatment of large-sized defects of femur and tibia based on the diamond concept

Aims

The aim of this study was to evaluate the radiological outcome of patients with large bone defects in the femur and tibia who were treated according to the guidelines of the diamond concept in our department (Centre for Orthopedics, Trauma Surgery, and Paraplegiology).

Methods

The following retrospective, descriptive analysis consists of patients treated in our department between January 2010 and December 2021. In total, 628 patients were registered, of whom 108 presented with a large-sized defect (≥ 5 cm). A total of 70 patients met the inclusion criteria. The primary endpoint was radiological consolidation of nonunions after one and two years via a modified Lane-Sandhu Score, including only radiological parameters.

Results

The mean defect size was 6.77 cm (SD 1.86), with the largest defect being 12.6 cm. Within two years after surgical treatment, 45 patients (64.3%) presented consolidation of the previous nonunion. After one year, six patients (8.6%) showed complete consolidation and 23 patients (32.9%) showed a considerable callus formation, whereas 41 patients (58.6%) showed a Lane-Sandhu score of 2 or below. Two years after surgery, 24 patients (34.3%) were categorized as Lane-Sandhu score 4, another 23 patients (32.9%) reached a score of 3, while 14 patients (20.0%) remained without final consolidation (score ≤ 2). A total of nine patients (12.9%) missed the two-year follow-up. The mean follow-up was 44.40 months (SD 32.00). The mean time period from nonunion surgery to consolidation was 16.42 months (SD 9.73).

Conclusion

Patients with presentation of a large-sized nonunion require a structured and sufficiently long follow-up to secure the consolidation of the former nonunion. Furthermore, a follow-up of at least two years is required in order to declare a nonunion as consolidated, given that a significant part of the nonunions declared as not consolidated at one year showed consolidation within the second year. Moreover, the proven "gold standard" of a two-step procedure, so called Masquelet technique, shows effectiveness.

Clinical Observations of the Effectiveness of the Masquelet Induced Membrane Technique in the Treatment of Critical Long-Bone Defects of the Lower and Upper Extremities

Background and Objectives: Successful treatment of severe trauma and fractures of the long bones with successful healing and bone union is still a significant challenge for surgeons. Unfortunately, up to 10% of long-bone fractures develop bone healing disorders. The aim of this study was to evaluate the results of treating bone defects with different etiologies in the upper and lower extremities using the induced membrane technique. Materials and Methods: We prospectively evaluated the radiological and clinical outcomes of 45 patients with severe bone defects treated with the induced membrane technique during the period from May 2021 to October 2023. The time to bone defect regeneration, size of the bone defect, and the cost of treatment were evaluated. Functional outcomes were assessed using the Disabilities of the Arm Shoulder and Hand (DASH) scale, SF-36, and the Lower Limb Functional Index (LLFI). Results: The mean follow-up time was 31 months (12-35). There were 20 patients with upper extremity bone defects and 25 with lower extremity bone defects. The mean defect length was 7.9 cm for the upper extremity (3.5-18) and 5.3 cm for the lower extremity (3-11). The mean times to achieve bone union and remodeling were 6.0 months (3-12) and 9 months (3-13) for the upper and lower limbs, respectively. Clinical evaluation at the end of treatment (achieving bone union) showed statistically significant improvements in the DASH, SF-36, and LLFI scales for pre- and postoperative outcomes. There was no statistical significance in the SF-36 clinical scale scores after surgical treatment compared to reconstructive treatment of upper and lower extremity bone defects. Results: The presented reconstructive approach to the treatment of bone defects and healing disorders and extensive analysis demonstrate the effectiveness of the induced membrane technique in a short follow-up period, with a relatively high level of patient comfort and good clinical results in the treatment of severe bone defects with particularly infectious etiologies.

FixThePig: a custom 3D-printed femoral intramedullary nailing for preclinical research applications

Background

Critical-size bone defects (CSBDs) pose significant challenges in clinical orthopaedics and traumatology. Developing reliable preclinical models that accurately simulate human conditions is crucial for translational research. This study addresses the need for a reliable preclinical model by evaluating the design and efficacy of a custom-made 3D-printed intramedullary nail (IMN) specifically for CSBDs in minipigs. The study aims to answer the following questions: Can a custom-made 3D-printed IMN be designed for femoral osteosynthesis in minipigs? Does the use of the custom-made IMN result in consistent and reproducible surgical procedure, particularly in the creation and fixation of CSBDs? Can the custom-made IMN effectively treat and promote bone consolidation of CSBDs?

Hypothesis

The custom-made 3D-printed IMN can be designed to effectively create, fix and treat CSBDs in minipigs, resulting in consistent surgical outcomes.

Materials and Methods

The IMN was designed based on CT scans of minipig femurs, considering factors such as femoral curvature, length, and medullary canal diameters. It was 3D-printed in titanium and evaluated through both in vitro and in vivo testing. Female Aachen minipigs underwent bilateral femoral surgeries to create and fix CSBDs using the custom-made IMN. Post-operative follow-up included X-rays and CT scans every 2 weeks, with manual examination of explanted femurs to assess consolidation and mechanical stability after 3 months.

Results

The custom-made IMN effectively fitted the minipig femoral anatomy and facilitated reproducible surgical outcomes. Symmetric double osteotomies were successfully performed, and allografts showed minimal morphological discrepancies. However, proximal fixation faced challenges, leading to non-union in several cases, while most distal osteotomy sites achieved stable consolidation.

Discussion

The custom-made 3D-printed IMN demonstrated potential in modelling and treating CSBDs in minipigs. While the design effectively supported distal bone healing, issues with proximal fixation highlight the need for further refinements. Potential improvements include better screw placement, additional mechanical support, and adaptations such as a reduction clamp or a cephalic screw to enhance stability and distribute forces more effectively.

[Modified Masquelet technique : Technique of the induced membrane in the course of time]

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

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

Introduction

Distal femur fractures are high-velocity injuries which accounts for 7-10% of all femoral fractures of which 5-10% are open fractures. Despite advances in techniques and implants, treatment remains a challenge, in many situations due to increased risk of infection, non-union and loss of range of motion. Surgical management of such complex injury includes radical debridement with stabilization followed by management of gap non-union with appropriate techniques and restores the range of motion.

Case Report

We present a case of 20-year-old man who had suffered multiple orthopedic trauma following accident. The patient had open comminuted fracture of the right distal femur, closed fracture of the same side tibia shaft, and right side closed both bone forearm shaft fracture. The patient was initially treated with debridement and knee-spanning limb reconstruction system (LRS). The patient developed infection and subsequently osteomyelitis of the distal femur shaft and gap non-union of 8 cm. The patient was operated for two-stage-induced membrane technique (IMT) and bone grafting using LRS followed by non-vascularized fibula strut grafting and plating. Quadriceps contracture was later on treated with quadricepsplasty to get good functional and radiological outcome.

Conclusion

A case of open distal femur comminuted fracture with a very small distal fragment complicated with osteomyelitis and gap non-union. We have shown that the use of IMT followed by non-vascularized fibula strut grafting and plating along with quadricepsplasty can give a very good outcome.

Management of infected bone defects of the femoral shaft by Masquelet technique: sequential internal fixation and nail with plate augmentation

BACKGROUND

To evaluate the effectiveness of a sequential internal fixation strategy and intramedullary nailing with plate augmentation (IMN/PA) for bone reconstruction in the management of infected femoral shaft defects using the Masquelet technique.

METHODS

We performed a retrospective descriptive cohort study of 21 patients (mean age, 36.4 years) with infected bone defects of the femoral shaft treated by the Masquelet technique with a minimum follow-up of 18 months after second stage. After aggressive debridement, temporary stabilisation (T1) was achieved by an antibiotic-loaded bone cement spacer and internal fixation with a bone cement-coated locking plate. At second stage (T2), the spacer and the locking plate were removed following re-debridement, and IMN/PA was used as definitive fixation together with bone grafting. We evaluated the following clinical outcomes: infection recurrence, bone union time, complications, and the affected limb's knee joint function.

RESULTS

The median and quartiles of bone defect length was 7 (4.75-9.5) cm. Four patients required iterative debridement for infection recurrence after T1. The median of interval between T1 and T2 was 10 (9-19) weeks. At a median follow-up of 22 (20-27.5) months, none of the patients experienced recurrence of infection. Bone union was achieved at 7 (6-8.5) months in all patients, with one patient experiencing delayed union at the distal end of bone defect due to screws loosening. At the last follow-up, the median of flexion ROM of the knee joint was 120 (105-120.0)°.

CONCLUSIONS

For infected femoral shaft bone defects treated by the Masquelet technique, sequential internal fixation and IMN/PA for the reconstruction can provide excellent mechanical stability, which is beneficial for early functional exercise and bone union, and does not increase the rate of infection recurrence.

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.

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

BACKGROUND

There is no effective consensus on the choice of internal fixation method for the Masquelet technique in the treatment of large segmental bone defects of the distal tibia. Thus, the study aimed to investigate the outcomes of the Masquelet technique combined with double plate fixation in the treatment of large segmental bone defects.

METHODS

This was a retrospective study involving 21 patients with large segmental bone defects of the distal tibia who were treated between June 2017 and June 2020. The length of bone defect ranged from 6.0 cm to 11 cm (mean, 8.19 cm). In the first stage of treatment, following complete debridement, a cement spacer was placed to induce membrane formation. In the second stage, double plate fixation and autologous cancellous bone grafting were employed for bone reconstruction. Each patient's full weight-bearing time, bone healing time, and Iowa ankle score were recorded, and the occurrence of any complications was noted.

RESULTS

All patients were followed up for 16 to 26 months (mean, 19.48 months). The group mean full weight-bearing time and bone healing time after bone grafting were 2.41 (± 0.37) months and 6.29 (± 0.66) months, respectively. During the treatment, one patient had a wound infection on the medial side of the leg, so the medial plate was removed. The wound completely healed after debridement without any recurrence. After extraction of iliac bone for grafting, one patient had a severe iliac bone defect, which was managed by filling the gap with a cement spacer. Most patients reported mild pain in the left bone extraction area after surgery. The postoperative Iowa ankle score range was 84-94 (P < 0.05). In this cohort, 15 cases were rated as "excellent", and 6 cases as "good" on the Iowa ankle scoring system.

CONCLUSION

The Masquelet technique combined with double plate fixation is a safe and effective method for the treatment of large segmental bone defects of the distal tibia.

Semi-focal bone transport versus traditional bone transport technique for the management of large tibial bone defects after trauma

How to deal with large tibial bone defects is still controversial. The purpose of this research was to compare the semi-focal bone transport (SFBT) technique with traditional bone transport (TBT) technique for treating such patients. Sixty-two patients were included and retrospectively analyzed. In all cases, after radical debridement large tibial bone defects remained. Patients were treated by the SFBT or TBT technique. The distraction, consolidation duration and complications were recorded by the patients' medical files. Based on the Association for the Study and Application of Methods of Ilizarov (ASAMI) standard, the bone and functional results were evaluated. The mean bone defect size was 7.7 ± 1.6 cm and 7.5 ± 2.1 cm for SFBT and TBT patients. The mean external fixation index (EFI) was 1.51 ± 0.14 months/cm and 1.89 ± 0.25 months/cm for SFBT and TBT patients (p < 0.05), respectively. With respect to bone and function results, there was no significant differences between the two groups (p > 0.05). The mean number of complications per patient was 1.1 ± 0.6 and 1.6 ± 0.7 for SFBT and TBT patients (p < 0.05). Compared to the traditional bone transport technique, patients using the semi-focal bone transport technique achieved better clinical effects, including shorter EFI and less complications. Therefore, the SFBT technique could be a new option for patients with large tibial bone defects.

The polymicrobial infection affects the infection recurrence rate (not failure) in treating femoral and tibial bone defects with the Masquelet technique-a comparative retrospective analysis of 54 patients with mono- and polymicrobial infections

INTRODUCTION

This study evaluated whether polymicrobial infection affects reoperation rates due to infection recurrence and treatment failure with the Masquelet technique in infected posttraumatic segmental bone defects of the femur and tibia.

METHODS

 We retrospectively analyzed patients treated between 2012 and 2021 in two trauma referral centers. We evaluated demographic data, injury, treatment, infection recurrence, failures, and bone healing rates according to whether the infection was mono- or polymicrobial. After uni-bivariate analysis between patients with polymicrobial and monomicrobial infection, we identified the variables associated with infection recurrence and failure through multivariate analysis.

RESULTS

 We analyzed 54 patients, 30 (55.55%) with tibial and 24 (44.44%) femoral segmental bone defects, with a mean follow-up of 41.7 ± 15.0 months. Forty-four (81.48%) presented monomicrobial, and 10 (18.51%) polymicrobial infections. Comparatively, the need for soft tissue reconstruction and the infection recurrence rate was significantly higher in patients with polymicrobial infections. There was no significant difference in the failure rate (20 vs. 6.81% p = 0.23). Multivariable logistic regression analysis identified the polymicrobial infection as the only independent variable associated with infection recurrence (Odds Ratio = 11.07; p = 0.0017).

CONCLUSION

 Our analysis suggests that polymicrobial infection is associated with a higher risk of infection recurrence in treating the femur and tibia segmental bone defects with the Masquelet technique. This information can help surgeons to inform patients about this and give them a realistic expectation of the outcome and the possibility of reoperation.

[Diagnostic and therapeutic work-up of infected tibial nonunion]

BACKGROUND

The failure of bone fracture healing is one of the major complications of fracture treatment, especially of the tibia due to its limited soft tissue coverage and high rate of open injuries. Although implant development is constantly progressing and modern surgical techniques are continuously improving, infected tibial nonunion plays a decisive role in terms of its variable clinical presentation.

OBJECTIVE

This article provides guidelines for the successful surgical treatment of infected tibial nonunion.

MATERIAL AND METHOD

Strategies are presented to identify infection as a cause of failure of fracture healing and to achieve infection and bone healing.

RESULTS

A significant amount of tibial nonunions primarily thought to be aseptic ultimately turn out to be infected nonunions.

CONCLUSION

The treatment of infected tibial nonunion requires extensive clinical, radiological and laboratory diagnostics as well as a profound biomechanical and biological understanding of the bone situation. This is the only way to achieve rapid osseous healing with as few revision interventions as possible.

Comparative bone healing with induced membrane technique (IMT) versus empty defects in septic and aseptic conditions in a novel rabbit humerus model

BACKGROUND

Long bone defects resulting from primary trauma or secondary to debridement of fracture-related infection (FRI) remain a major clinical challenge. One approach often used is the induced membrane technique (IMT). The effectiveness of the IMT in infected versus non-infected settings remains to be definitively established. In this study we present a new rabbit humerus model and compare the IMT approach between animals with prior infection and non-infected equivalents.

METHODS

A 5 mm defect was created in the humerus of New Zealand White rabbits (n = 53) and fixed with a 2.5 mm stainless steel plate. In the non-infected groups, the defect was either left empty (n = 6) or treated using the IMT procedure (PMMA spacer for 3 weeks, n = 6). Additionally, both approaches were applied in animals that were inoculated with Staphylococcus aureus 4 weeks prior to defect creation (n = 5 and n = 6, respectively). At the first and second revision surgeries, infected and necrotic tissues were debrided and processed for bacteriological quantification. In the IMT groups, the PMMA spacer was removed 3 weeks post implantation and replaced with a beta-tricalcium phosphate scaffold and bone healing observed for a further 10 weeks. Infected groups also received systemic antibiotic therapy. The differences in bone healing between the groups were evaluated radiographically using a modification of the radiographic union score for tibial fractures (RUST) and by semiquantitative histopathology on Giemsa-Eosin-stained sections.

RESULTS

The presence of S. aureus infection at revision surgery was required for inclusion to the second stage. At the second revision surgery all collected samples were culture negative confirming successful treatment. In the empty defect group, bone healing was increased in the previously infected animals compared with non-infected controls as revealed by radiography with significantly higher RUST values at 6 weeks (p = 0.0281) and at the end of the study (p = 0.0411) and by histopathology with increased cortical bridging (80% and 100% in cis and trans cortical bridging in infected animals compared to 17% and 67% in the non-infected animals). With the IMT approach, both infected and non-infected animals had positive healing assessments.

CONCLUSION

We successfully developed an in vivo model of bone defect healing with IMT with and without infection. Bone defects can heal after an infection with even better outcomes compared to the non-infected setting, although in both cases, the IMT achieved better healing.

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.

Matched-Pair Analysis: Large-Sized Defects in Surgery of Lower Limb Nonunions

BACKGROUND

The treatment of large-sized bone defects remains a major challenge in trauma and orthopaedic surgery. Although there are many treatment options, there is still no clear guidance on surgical management, and the influence of defect size on radiological and clinical outcome remains unclear due to the small number of affected patients. The aim of the present study was to determine the influence of defect size on the outcome of atrophic and infected nonunions of the tibia or the femur based on the diamond concept in order to provide recommendations for treatment guidance.

PATIENTS AND METHODS

All medical records, surgical reports, laboratory data and radiological images of patients treated surgically for atrophic or infected nonunions of the lower limbs (femur or tibia) between 1 January 2010 and 31 December 2020 were examined. Patients with proximal, diaphyseal or distal nonunions of the femur or tibia who were surgically treated at our institution according to the "diamond concept" and attended our standardised follow-up program were included in a database. Surgical treatment was performed as a one- or two-step procedure, depending on the type of nonunion. Patients with a segmental bone defect ≥5 cm were matched with patients suffering a bone defect <5 cm based on five established criteria. According to our inclusion and exclusion criteria, 70 patients with a bone defect ≥5 cm were suitable for analysis. Two groups were formed by matching: the study group (bone defect ≥5 cm; n = 39) and control group (bone defect <5 cm; n = 39). The study was approved by the local ethics committee (S-262/2017).

RESULTS

The mean defect size was 7.13 cm in the study and 2.09 cm in the control group. The chi-square test showed equal consolidation rates between the groups (SG: 53.8%; CG: 66.7%). However, the Kaplan-Meier curve and log-rank test showed a significant difference regarding the mean duration until consolidation was achieved, with an average of 15.95 months in the study and 9.24 months in the control group (α = 0.05, p = 0.001). Linear regression showed a significant increase in consolidation duration with increasing defect size (R² = 0.121, p = 0.021). Logistic regression modelling showed a significant negative correlation between consolidation rate and revision performance, as well as an increasing number of revisions, prior surgeries and total number of surgeries performed on the limb. Clinical outcomes showed equal full weight bearing of the lower extremity after 5.54 months in the study vs. 4.86 months in the control group (p = 0.267).

CONCLUSION

Surprisingly, defect size does not seem to have a significant effect on the consolidation rate and should not be seen as a risk factor. However, for the treatment of large-sized nonunions, the follow-up period should be prolonged up to 24 months, due to the extended time until consolidation will be achieved. This period should also pass before a premature revision with new bone augmentation is performed. In addition, it should be kept in mind that as the number of previous surgeries and revisions increases, the prospects for consolidation decrease and a change in therapeutic approach may be required.

Management of bone loss in acute severe open tibial fractures: a retrospective study of twenty nine cases-a treatment strategy with bone length preservation

PURPOSE

The present study investigated the outcomes of bone loss associated with acute open tibial fractures classified as Gustilo-Anderson classification grade III B (GIIIB) using a bone length preservation strategy.

METHODS

Among acute GIIIB open tibial fractures, 29 limbs of 29 patients requiring bone loss treatment were included. The reconstruction methods for bone loss were selected among the Masquelet technique (MT), bone transport (BT), acute shortening followed by gradual lengthening (ASGL), and free vascularized fibula graft (FVFG). Primary outcome measures were the rate of bone union and time to bone union.

RESULTS

The median radiographic apparent bone gap (RABG) was 46.75 mm. Bone loss was treated with ASGL only in two patients in whom it was not possible to cover large soft tissue defects by a single free latissimus dorsi (LD) myocutaneous flap (with the serratus anterior (SA) muscle). The other 27 patients underwent soft tissue reconstruction and bone loss treatment with the preservation of bone length, including the MT for 23, BT for six, and FVFG for one. The bone union rate was 75.9%, and the median time to bone union was six months. Salvage surgeries were performed on all seven patients with nonunion; all of whom eventually achieved bony union.

CONCLUSION

Bone loss associated with acute GIIIB open tibial fractures were treated with "bone length preservation" if the size of the soft tissue defect was less than the size that was covered by a single LD myocutaneous flap (with the SA muscle).

The antibiotics supplemented bone cement improved the masquelet's induced membrane in a rat femur critical size defect model

BACKGROUND

Masquelet technique is a two-stage surgical procedure used in the treatment of critical-size bone defects (CSD). Adding antibiotics to polymethylmethacrylate (PMMA) is still questionable to create higher quality induced membrane (IM). The aim of the study was to evaluate the effects of three antibiotic-supplemented cement, fusidic acid, teicoplanin, and gentamicin, on osteogenesis and IM progression applied to rat femur CSD model by comparing histopathological, biochemical, and immunohistochemical findings.

METHODS

Twenty-eight male rats were divided into four groups control, gentamicin (G), teicoplanin (T), and fusidic acid (FA). A 10 mm CSD was created in rat femurs. In the postoperative 4th week, intracardiac blood samples were collected for biochemical analysis of bone alkaline phosphatase (BALP), osteocalcin (OC), and tumor necrosis factor-alpha (TNF-α) levels. IMs obtained in secondary operation were fixed and prepared for histopathological scoring of membrane progression and immunohistochemical evaluation of rat-specific Transforming Growth Factor-Beta (TGF-β), Runt-related Transcription Factor 2 (Runx2), and Vascular Endothelial Growth Factor (VEGF) expressions.

RESULTS

Levels of BALP and OC in serum didn't change among groups significantly while serum TNF-α levels significantly decreased in all antibiotic groups compared to the control group (P = 0.017). Histological scores of groups FA and T were significantly higher than those of groups Control and G (P = 0.0007). IMs of groups T and FA showed good progression while those of groups Control and G were also moderately progressed. A significant increase in TGF-β expression was observed in group G and FA (P = 0.001) while a significant increase in the expression of VEGF was observed in groups G and T compared to the control group (P = 0.036).

CONCLUSIONS

The bone cement impregnated with thermostable and safe antibiotics, gentamicin, fusidic acid, and teicoplanin can increase osteogenesis and support IM progression by increasing the expressions of TGF-β and VEGF. Anabolic effects of induced membranes used in the treatment of critical-size bone defects can be enhanced by antibiotic-supplemented PMMAs applied by altering the original technique.

Induced Membrane Technique for the Management of Segmental Femoral Defects: A Systematic Review and Meta-Analysis of Individual Participant Data

Several modifications of the induced membrane technique (IMT) have been reported, but there is no consensus regarding their results and prognosis. Moreover, most studies have focused on tibial defects; no meta-analysis of the treatment of femoral defects using the IMT has been reported. This systematic review and meta-analysis aimed to identify the potential risk factors of post-procedural complications following the treatment of segmental femoral defects using the IMT. A comprehensive search was performed on the Cochrane Library, EBSCO, EMBASE, Ovid, PubMed, Scopus, and Web of Science databases, using the keywords "femur," "Masquelet technique," and "induced membrane technique." Original articles composed in English, having accessible individual patient data, and reporting more than two cases of bony defect or nonunion of femur or more than five cases of any body part were included. Post-procedural bone graft infections, final union status, and union time after second-stage operation were analyzed. Fourteen reports, including 90 patients, were used in this study. External fixation in second-stage surgery had an odds ratio of 9.267 for post-procedural bone graft infection (p = 0.047). The odds ratio of post-procedural bone graft infection and age >65 years for final non-union status was 51.05 (p = 0.003) and 9.18 (p = 0.042). Shorter union time was related to impregnated antibiotics in the spacer (p = 0.005), transplanting all-autologous grafts (p = 0.042), and the application of intramedullary nails as the second-stage fixation method (p = 0.050). The IMT appears to be reasonable and reproducible for femoral segmental bone defects. Several preoperative and surgical factors may affect post-procedural complications and union time.

Masquelet technique in military practice: specificities and future directions for combat-related bone defect reconstruction

Because of its simplicity, reliability, and replicability, the Masquelet induced membrane technique (IMT) has become one of the preferred methods for critical bone defect reconstruction in extremities. Although it is now used worldwide, few studies have been published about IMT in military practice. Bone reconstruction is particularly challenging in this context of care due to extensive soft-tissue injury, early wound infection, and even delayed management in austere conditions. Based on our clinical expertise, recent research, and a literature analysis, this narrative review provides an overview of the IMT application to combat-related bone defects. It presents technical specificities and future developments aiming to optimize IMT outcomes, including for the management of massive multi-tissue defects or bone reconstruction performed in the field with limited resources.

[Infected nonunion: diagnostic and therapeutic work-up]

BACKGROUND

Septic nonunion is one of the major complications in fracture healing. The challenge is to identify the infection as the cause of nonunion first and then to achieve healing of the infection and the bone.

OBJECTIVE

Because of the more heterogeneous appearance of an infected nonunion, the prevalence of germ detection in surgical nonunion revision is often underestimated.

MATERIAL AND METHODS

In a retrospective study between 2010 and 2017, 86 patients with radiologically confirmed femoral shaft nonunion without clinical evidence and unremarkable medical history of a florid infection as the cause of nonunion, who had undergone primary single-stage surgical nonunion revision were analyzed. At least four intraoperatively obtained samples were evaluated for microbiological diagnosis. A distinction was made between tissue samples with subsequent 48‑h short-term incubation and tissue samples with 14-day long-term cultivation. The finding "germ detection" was made if at least two of the samples demonstrated bacterial growth.

RESULTS

In 18 of 86 patients with a nonunion preoperatively judged to be aseptic, positive bacterial evidence was obtained after short-term incubation. After long-term cultivation, positive bacterial detection was possible in 38 of 86 patients with a femoral shaft nonunion initially classified as aseptic. Regarding potential risk factors, the two groups demonstrated no relevant differences. In 29 patients, 1 pathogen was isolated from the obtained samples, whereas in the remaining 9 patients, a mixed culture with an average of 2.9 ± 0.5 different bacteria was detected. Identification revealed mainly low-virulence bacteria, most commonly Staphylococcus epidermidis.

CONCLUSION

If the preoperative diagnostics including clinical, laboratory and radiological examination as well as a careful anamnesis reveal indications of a possible infectious event, the surgical nonunion revision should be performed in two stages with specimen collection before definitive nonunion revision. For microbiological diagnosis, several representative tissue samples should independently be obtained from the nonunion site and incubated for 14 days. Only in the absence of evidence of septic nonunion is a single-stage procedure suggested.

Induced membrane technique for acute bone loss and nonunion management of the tibia

Objectives:

To report our experience and clinical results of using the Masquelet technique for the treatment of tibial nonunions and acute traumatic tibial bone defects.

Design:

Retrospective study of prospectively collected data (Level IV).

Setting:

Level I trauma center in the UK.

Patients/Participants:

Consecutive patients with tibial nonunions and open fractures associated with bone loss.

Intervention: Two-stage Masquelet Procedure for the tibia.

Main Outcome Measurements:

Clinical and imaging assessment at 6 weeks, 3,6,9,12 months, or until pain-free mobilization and union.

Results:

There were 17 eligible patients, with a mean size of bone defect of 6 cm (range, 4–8 cm) and an 88.2% union rate at a mean of 8 months (range 5–18 months). Mean range of motion was 95 degrees of knee flexion (range 80°–130°). All patients but 2 returned to their previous occupation.

Conclusions:

The Masquelet technique is simple, effective, and has a high rate of success for the management of a variety of situations including acute bone loss or infected nonunions and is associated with a low incidence of complications.

Effects of PMMA spacer loaded with varying vancomycin concentrations on bone regeneration in the Masquelet technique

Whether antibiotics should be included remains greatly debated in Masquelet technique. This study intended to determine the effect of polymethyl methacrylate (PMMA) spacer loaded with different vancomycin concentrations on bone defect repair. Hollow cylindrical spacers consisting of PMMA and varying vancomycin concentrations (0, 1, 2, 4, 6, 8, and 10 g) were prepared. Critical bone defects of rabbits were created at the radial shaft, and spacers were implanted and subsequently intramedullary fixed with retrograde Kirschner’s wires (n = 4 for each vancomycin concentration). After 4 weeks, the induced membranes were opened and cancellous allografts were implanted into the defects. Eight weeks post-operatively, the results of X-ray, histology, and micro-CT revealed that some cortical bone was formed to bridge the gap and the bone marrow cavity was formed over time. Quantitatively, there was more new bone formation in the groups with a relatively lower vancomycin concentration (1–4 g) compared with that in the groups with a higher vancomycin concentration (6–10 g). Our findings suggested that PMMA spacers loaded with relatively lower vancomycin concentrations (1–4 g) did not interfere with new bone formation, whereas spacers loaded with relatively higher vancomycin concentrations (6–10 g) had negative effects on bone formation.

Advances in 3D printing of composite scaffolds for the repairment of bone tissue associated defects

The conventional methods of using autografts and allografts for repairing defects in bone, the osteochondral bone and the cartilage tissue have many disadvantages, like donor site morbidity and shortage of donors. Moreover, only 30% of the implanted grafts are shown to be successful in treating the defects. Hence, exploring alternative techniques such as tissue engineering to treat bone tissue associated defects is promising as it eliminates the above-mentioned limitations. To enhance the mechanical and biological properties of the tissue engineered product, it is essential to fabricate the scaffold used in tissue engineering by the combination of various biomaterials. Three-dimensional (3D) printing, with its ability to print composite materials and with complex geometry seems to have a huge potential in scaffold fabrication technique for engineering bone associated tissues.This review summarizes the recent applications and future perspectives of 3D printing technologies in the fabrication of composite scaffolds used in bone, osteochondral and cartilage tissue engineering. Key developments in the field of 3D printing technologies involves the incorporation of various biomaterials and cells in printing composite scaffolds mimicking physiologically relevant complex geometry & gradient porosity. Much recently, the emerging trend of printing smart scaffolds which can respond to external stimulus such as temperature, pH and magnetic field, known as 4D printing is gaining immense popularity and can be considered as the future of 3D printing applications in the field of tissue engineering. This article is protected by copyright. All rights reserved.

Fibula lengthening then centralization for the treatment of pseudoarthrosis at the middle third of tibia with large leg-length discrepancy - A case report

INTRODUCTION AND IMPORTANCE

Tibial dysplastic pseudoarthrosis associated with large leg-length discrepancy and extensive scarring was a great challenge for orthopedic surgeons. The treatment for these lesions was not defined.

CASE PRESENTATION

We report a 24-year-old case of dysplastic pseudoarthrosis at the middle third of the right tibia with a 10 cm leg-length discrepancy and a 250 medial deviation and 200 internal torsion due to osteomyelitis 14 years previously. She was treated by fibula lengthening then centralization for the treatment of tibial pseudoarthrosis. Eight months after the operation, the patient reported no pain and became capable of walking without an orthosis. X-rays showed full bone union at the proximal tibiofibular synostosis and the lengthening site of the right fibula. The distal tibiofibular synostosis was healing. The range of movement of the knee and ankle was restored.

CLINICAL DISCUSSION

This technique was different from the Huntington procedure. A good union between the transposed fibula and the remaining part of the fibula brought a better strength of the reconstructed tibia. The tibial pseudoarthrosis, leg-length discrepancy, and malalignment had been solved by our techniques. The procedure was easy, rapid, and inexpensive without requiring microsurgery skills and special devices.

CONCLUSION

Leg lengthening then centralization of ipsilateral fibular graft is an excellent option for reconstruction of a tibial pseudarthrosis with a large leg-length discrepancy. It is a safe, rapid, and inexpensive procedure. The procedure was not difficult, and microvascular skills and special devices were not required.

LEVEL OF EVIDENCE

A case report.

Treatments, cost and healthcare utilization of patients with segmental bone defects

BACKGROUND

Treatment of large segmental defects in skeletal long bones is challenging. Heterogeneity in patient presentation further increase the difficulty in designing and running randomized trials, hence the paucity of published data with large patient numbers. This study was designed to help understand patient presentation, costs and outcomes, using real world data sources.

METHODS

Two data sources (Premier healthcare database (PHD) and IBM® MarketScan® Commercial Claims and Medicaid databases) were utilized, PHD for intraoperative and cost analyses, MarketScan for payer costs and longitudinal (2-year) outcomes. Patients were included in the analysis if they had diagnoses of osteomyelitis, non-union or open (acute) fractures, treated with bone graft and/or spacers, using either the Masquelet or external frames. Patient cohorts were defined by diagnosis at index (acute fracture, osteomyelitis, non-union) and descriptive statistics were conducted for patient variables (demographic, comorbidities) and outcomes. Risk of complications were estimated using logistic regression models. Hospital and payer costs for index and follow-up periods, were estimated using least means square estimators from generalized linear model outputs. All costs and payments were adjusted for inflation to 2019 consumer price-index.

RESULTS

904 patients were identified in PHD (414 fractures, 388 osteomyelitis and 102 nonunion patients). Main comorbidities at time of initial surgery were hypertension (32.7%) followed by obesity (22.1%), diabetes with complications (20.9%) and chronic pulmonary disease (20.6%). Significant variability in surgical operating room time and length of stay were observed, with averages of 484.7 minutes and 11.7 days, respectively. Two-year postoperative infection rates ranged from 33.1% - 58.5%, the highest infection rates being reflective of ongoing infections in patients initially treated for osteomyelitis. Amputation rates ranged from 10.0% in patients with bone loss due to acute factures to 14.5% in patients with osteomyelitis. Osteomyelitis patients were also the costliest, with 12-months hospital costs averaging US$ 156.818 (95%CI: 112,970-217,685).

CONCLUSION

This study identified high complication rates and costs of segmental bone repair surgery. All patients with segmental bone defects had high costs and risks but patients with osteomyelitis were at significant risk for increased cost and complications, including amputation. Medical innovation is particularly important for this high-risk patient group.

The Basic Science Behind the Clinical Success of the Induced Membrane Technique for Critical-Sized Bone Defects

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The induced membrane technique (IMT) takes advantage of an osteoinductive environment that is created by the placement of a cement spacer into a bone defect.

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Most commonly, a polymethylmethacrylate (PMMA) spacer has been used, but spacers made from other materials have emerged and achieved good clinical outcomes.

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The IMT has demonstrated good results for long-bone repair; however, more research is required in order to optimize union rates as well as delineate more precise indications and surgical timing.

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.