Bone reconstruction with modified Masquelet technique in open distal femoral fractures: a case series.

BACKGROUND: Large bone defects require complex treatment, multidisciplinary resources, and expert input, with surgical procedures ranging from reconstruction and salvage to amputation. The aim of this study was to provide the results of a case series of open comminuted intra-articular distal femoral fractures with significant bone loss that were managed by early fixation using anatomical plates and a modified Masquelet technique with the addition of surgical propylene mesh. METHODS: This retrospective study included all patients referred to our institution with OTA/AO C3 distal femur open fractures and meta-diaphyseal large bone loss between April 2019 and February 2021. We treated the fractures with irrigation and debridement, acute primary screw and plate fixation in the second look operation, and Masquelet method using shell-shaped antibiotic beads supplemented by propylene surgical mesh to keep the cements in place. The second step of the procedure was conducted six to eight weeks later with bone grafting and mesh augmentation to contain bone grafts. Surprisingly, hard callus formation was observed in all patients at the time of the second stage of Masquelet procedure. RESULTS: All five patients' articular and meta-diaphyseal fractures with bone loss healed without major complications. The average union time was 159 days. The mean knee range of motion was 5-95 degrees. The average Lower Extremity Functional Score (LEFS) was 49 out of 80. CONCLUSIONS: Combination of early plate fixation and the modified Masquelet technique with polypropylene mesh is an effective method for managing large bone defects in open intra-articular distal femoral fractures with bone loss, resulting in shorter union time possibly associated with the callus formation process. This technique may also be applicable to the management of other similar fractures specially in low-income and developing areas.

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

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

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

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

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

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

Surgical repair of large segmental bone loss with the induced membrane technique: patient reported outcomes are comparable to nonunions without bone loss.

OBJECTIVE: To compare the outcomes of patients with segmental bone loss who underwent repair with the induced membrane technique (IMT) with a matched cohort of nonunion fractures without bone loss. DESIGN: Retrospective analysis on prospectively collected data. SETTING: Academic medical center. PATIENTS: Two cohorts of patients, those with upper and lower extremity diaphyseal large segmental bone loss and those with ununited fractures, were enrolled prospectively between 2013 and 2020. Sixteen patients who underwent repair of 17 extremities with segmental diaphyseal or meta-diaphyseal bone defects treated with the induced membrane technique were identified, and matched with 17 patients who were treated for 17 fracture nonunions treated without an induced membrane. Sixteen of the bone defects treated with the induced membrane technique were due to acute bone loss, and the other was a chronic aseptic nonunion. MAIN OUTCOME MEASUREMENTS: Healing rate, time to union, functional outcome scores using the Short Musculoskeletal Functional Assessment (SMFA) and pain assessed by the Visual Analog Scale (VAS). RESULTS: The initial average defect size for patients treated with the induced membrane technique was 8.85 cm. Mean follow-up times were similar with 17.06 ± 10.13 months for patients treated with the IMT, and 20.35 ± 16.68. months for patients treated without the technique. Complete union was achieved in 15/17 (88.2%) of segmental bone loss cases treated with the IMT and 17/17 (100%) of cases repaired without the technique at the latest follow up visit. The average time to union for patients treated with the induced membrane technique was 13.0 ± 8.4 months and 9.64 ± 4.7 months for the matched cohort. There were no significant differences in reported outcomes measured by the SMFA or VAS. Patients treated with the induced membrane technique required more revision surgeries than those not treated with an induced membrane. CONCLUSION: Outcomes following treatment of acute bone loss from the diaphysis of long bones with the induced membrane technique produces clinical and radiographic outcomes similar to those of long bone fracture nonunions without bone loss that go on to heal. LEVEL OF EVIDENCE: III.

Increased Yield of Extracellular Vesicles after Cytochalasin B Treatment and Vortexing.

Extracellular vesicles (EVs) are promising therapeutic instruments and vectors for therapeutics delivery. In order to increase the yield of EVs, a method of inducing EVs release using cytochalasin B is being actively developed. In this work, we compared the yield of naturally occurring extracellular vesicles and cytochalasin B-induced membrane vesicles (CIMVs) from mesenchymal stem cells (MSCs). In order to maintain accuracy in the comparative analysis, the same culture was used for the isolation of EVs and CIMVs: conditioned medium was used for EVs isolation and cells were harvested for CIMVs production. The pellets obtained after centrifugation 2300× g, 10,000× g and 100,000× g were analyzed using scanning electron microscopy analysis (SEM), flow cytometry, the bicinchoninic acid assay, dynamic light scattering (DLS), and nanoparticle tracking analysis (NTA). We found that the use of cytochalasin B treatment and vortexing resulted in the production of a more homogeneous population of membrane vesicles with a median diameter greater than that of EVs. We found that EVs-like particles remained in the FBS, despite overnight ultracentrifugation, which introduced a significant inaccuracy in the calculation of the EVs yield. Therefore, we cultivated cells in a serum-free medium for the subsequent isolation of EVs. We observed that the number of CIMVs significantly exceeded the number of EVs after each step of centrifugation (2300× g, 10,000× g and 100,000× g) by up to 5, 9, and 20 times, respectively.

Feasibility evaluation of the induced membrane technique with structural autologous strip bone graft management of phalangeal and metacarpal segmental defects using radiography.

PURPOSE: The purpose of this study was to explore the feasibility and evaluate the clinical outcomes of treatment for phalangeal and metacarpal segmental defects with the induced membrane technique and autologous structural bone grafting. METHODS: Sixteen patients who sustained phalangeal or metacarpal bone segmental defects were treated by the induced membrane technique and autologous structural bone grafting from June 2020 to June 2021 at our center. RESULTS: The average follow-up was 24 weeks (range, 12-40 weeks). Radiography demonstrated union of all bone grafts after an average of 8.6 weeks (range, 8-12 weeks). All incisions at donor and recipient sites demonstrated primary heal without infection complications. The mean visual analog scale score of the donor site was 1.8 (range, 0-5), with a good score in 13 cases and a fair score in 3. The mean total active motion of the fingers was 179.9°. CONCLUSIONS: The feasibility of the induced membrane technique and structural treatment with a cylindrical bone graft for segmental bone defects of the metacarpal or phalanx is demonstrated by follow-up radiography results. The bone graft provided much more stability and structural support in the bone defects, and the bone healing time and bone union rate were ideal.

Varying degrees of spontaneous osteogenesis of Masquelet's induced membrane: experimental and clinical observations.

BACKGROUND: Masquelet's induced membrane (IM) has osteogenesis activity, but IM spontaneous osteogenesis (SO) has not been described previously. OBJECTIVES: To report on varying degrees of IMSO and analyze its possible causes. METHODS: Twelve eight-week-old male Sprague-Dawley rats with 10 mm right femoral bone defects who received the first stage of IM technique (IMT) were used to observe the SO. In addition, clinical data from patients with bone defects who received the first stage of IMT with an interval of > 2 months post-operatively and exhibited SO between January 2012 and June 2020 were retrospectively analyzed. The SO was divided into four grades according to the amount and characteristics of the new bone formation. RESULTS: At twelve weeks, grade II SO was observed in all rats, and more new bone was formed in the IM near the bone end forming an uneven margin. Histology revealed bone and cartilage foci in the new bone. Four of the 98 patients treated with the first stage of IMT exhibited IMSO, including one female and three males with a median age of 40.5 years (range 29-52 years). The bone defects were caused by severe fractures and infection in two cases and by infection or tumor in one case each. Partial or segmental defects occurred in two cases. The time interval between inserting a cement spacer and diagnosis of SO ranged from six months to nine years. Two cases were grade I, and one case each of grades III and IV. CONCLUSION: Varying degrees of SO confirm the existence of the IMSO phenomenon. Bioactive bone tissue or local inflammation and a long time interval are the primary reasons underlying enhancement of the osteogenic activity of IM and leading to SO, which tends to take place as endochondral osteogenesis.

Vascularized Bone Grafting Versus the 2-Stage Masquelet Technique for Upper-Extremity Bone Reconstruction: A Meta-Analysis.

PURPOSE: Vascularized bone grafting (VBG) has been described as the technique of choice for larger bone defects in bone reconstruction, yielding excellent results at the traditional threshold of 6 cm as described in the literature. However, we hypothesize that the 2-stage Masquelet technique provides equivalent union rates for upper-extremity bone defects regardless of size, while having no increase in the rate of patient complications. METHODS: A systematic literature review was conducted using PubMed and Scopus for outcomes after VBG and the Masquelet technique for upper-extremity bone defects of the humerus, radius, ulna, metacarpal, or phalanx (carpal defects were excluded). A meta-analysis was performed to compare outcomes following VBG and the Masquelet technique at varying defect sizes. RESULTS: There were 77 VBG (295 patients) and 25 Masquelet (119 patients) studies that met inclusion criteria. Patients undergoing the Masquelet technique had defect sizes ranging from 0-15 cm (average 4.5 cm), while patients undergoing VBG had defect sizes ranging from 0-24 cm (average 5.9 cm). The union rate for Masquelet patients was 94.1% with an average time to union of 5.8 months, compared to 94.9% and 4.4 months, respectively, for VBG patients. We did not identify a defect size threshold at which VBG demonstrated a significantly higher union rate. No statistically significant difference was found in union rates between techniques when using multivariable logistic regression analysis. CONCLUSION: There was no statistically significant difference in union rates between VBG and the Masquelet technique in upper-extremity bone defects regardless of defect size. Surgeons may consider the Masquelet technique as an alternative to VBG in large bone defects of the upper extremity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Outcomes After Use of the Induced Membrane Technique for Fractures of the Upper Extremity.

PURPOSE: The purpose of this study was to review a series of cases in which the induced membrane technique was used for fractures with segmental bone loss in the upper extremity. We aimed to examine patient indications, outcomes based on union rates, and complications associated with this technique. METHODS: An institutional review board-approved database at our institution was used to identify patients based on either diagnosis or procedure codes commonly used during the induced membrane treatment. The database was queried between 2003 and 2020 and included patients with segmental bone defects from acute trauma, nonunions, and infections. Demographic data, mechanism of injury, size and extent of the bone defect, treatment indication and methods along with intraoperative and postoperative complications were retrospectively reviewed. RESULTS: We identified 23 patients who met our inclusion criteria, including 15 patients with traumatic segmental bone loss and 8 patients with chronic nonunions and/or infections. Fourteen cases involving the bones of the forearm, 8 cases involving the metacarpals and 3 cases involving the phalanges were identified. Radiographic union was ultimately demonstrated in 21/23 patients (91.3%) with a median time to union of 20 weeks (range 13-29 weeks). A total of 10 patients required unplanned reoperation, with 4 nonunions requiring repeat plating and grafting procedures, and 1 patient ultimately underwent amputation for persistent infection. CONCLUSIONS: The induced membrane technique represents an effective treatment option for acute traumatic bone loss as well as chronic fracture nonunions. The technique has potential challenges, as 10 patients (43.5%) in our series required unplanned reoperations with 4 patients (17.4%) requiring a repeat intervention for persistent nonunion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Functional outcomes and health-related quality of life after reconstruction of segmental bone loss in femur and tibia using the induced membrane technique.

INTRODUCTION: The induced membrane technique (IMT), frequently called Masquelet technique, is an operative, two-staged technique for treatment of segmental bone loss. Previous studies mainly focused on radiological outcome parameters and complication rates, while functional outcomes and health-related quality of life after the IMT were sparsely reported. MATERIALS AND METHODS: Retrospective study containing of a chart review as well as a clinical and radiological follow-up examination of all patients treated with the IMT at a single institution. The clinical outcomes were evaluated using the Lower Extremity Functional Scale (LEFS), the Short-Form-36 (SF-36) and the visual analog scale (VAS) for pain. The radiographic evaluation contained of standard anteroposterior and lateral, as well as hip-knee-ankle (HKA) radiographs. RESULTS: Seventeen patients were included in the study. All had suffered high-energy trauma and sustained additional injuries. Ten bone defects were localized in the femur and seven in the tibia. Ten patients underwent additional operative procedures after IMT stage 2, among them three patients who contracted a postoperative deep infection. The median LEFS was 59 (15-80), and the SF-36 physical component summary (PCS) and mental component summary (MCS) were 41.3 (24.0-56.1) and 56.3 (13.5-66.2), respectively. The median length of the bone defect was 9 (3-15) cm. In 11 patients, union was obtained directly after IMT stage 2. Bone resorption was observed in two patients. At follow-up, 16 of the 17 bone defects had healed. The median follow-up was 59 months (13-177). CONCLUSION: Our results show a high occurrence of complications after IMT stage 2 in segmental bone defects of femur and tibia requiring additional operative procedures. However, fair functional outcomes as well as a good union rate were observed at follow-up.

Surgical treatment of critical size bone defects with Masquelet technique versus bone transport: a systematic review and meta-analysis of comparative studies.

INTRODUCTION: To date, the management of critical-sized bone defects lacks a universally accepted approach among orthopedic surgeons. Currently, the main options to treat severe bone loss include autologous grafting, free vascularized bone transfer, bone transport and induced-membrane technique. The purpose of this study is to critically compare the outcomes of Masquelet technique and bone transport to provide a higher level of evidence regarding the indexed techniques. MATERIAL AND METHODS: The authors conducted a systematic search on several databases according to the PRISMA guidelines. English-written reports comparing outcomes of the Masquelet technique versus the bone transport technique in patients with critical-sized defects in lower extremities were included. RESULTS: Six observational studies involving 364 patients were included. The systematic review and meta-analysis of pooled data showed no significant difference in most outcomes, except for ASAMI bone outcomes and residual deformity, which showed better results in the bone transport group. The 64% of patients treated with Masquelet technique obtained excellent/good bone ASAMI results compared to 82.8% with bone transport (p = 0.01). Post-operative residual deformity was 1.9% with the bone transport method versus 9.7% with the Masquelet technique (p = 0.02). CONCLUSIONS: Both the Masquelet technique and bone transport showed comparable results for the management of critical-sized bone defects of the lower limb. However, these findings must be carefully interpreted due to the high risk of bias. Further prospective randomized controlled trials are necessary to better clarify the strengths and limitations of these two techniques and to identify the variables affecting the outcomes.

Management of wounds with exposed bone structures using an induced-membrane followed by polymethyl methacrylate and second-stage skin grafting in the elderly with a 3-year follow-up.

The treatment of traumatic wounds with exposed bone or tendons is often challenging. An induced membrane (IM) is used to reconstruct bone defects, as it provides an effective and sufficient blood supply for bone and soft-tissue reconstruction. This study explored a novel two-stage strategy for wound management, consisting of initial wound coverage with polymethyl methacrylate (PMMA) and an autologous split-thickness skin graft under the IM. Fifty inpatients were enrolled from December 2016 to December 2019. Each patient underwent reconstruction according to a two-stage process. In the first stage, the defect area was thoroughly debrided, and the freshly treated wound was then covered using PMMA cement. After 4-6 weeks, during the second stage, the PMMA cement was removed to reveal an IM covering the exposed bone and tendon. An autologous split-thickness skin graft was then performed. Haematoxylin and eosin (H&E) staining and immunohistochemical analysis of vascular endothelial growth factor (VEGF), CD31 and CD34 were used to evaluate the IM and compare it with the normal periosteal membrane (PM). The psychological status and the Lower Extremity Function Scale (LEFS) as well as any complications were recorded at follow-up. We found that all skin grafts survived and evidenced no necrosis or infection. H&E staining revealed vascularised tissue in the IM, and immunohistochemistry showed a larger number of VEGF-, CD31- and CD34-positive cells in the IM than in the normal PM. The duration of healing in the group was 5.40 ± 1.32 months with a mean number of debridement procedures of 1.92 ± 0.60. There were two patients with reulceration in the group. The self-rating anxiety scale scores ranged from 35 to 60 (mean 48.02 ± 8.12). Postoperatively, the LEFS score was 50.10 ± 9.77. Finally, our strategy for the management of a non-healing wound in the lower extremities, consisting of an IM in combination with skin grafting, was effective, especially in cases in which bony structures were exposed in the elderly. The morbidity rate was low.

Starfish oocytes of A. pectinifera reveal marked differences in sperm-induced electrical and intracellular calcium changes during oocyte maturation and at fertilization.

Although changes in membrane potential and intracellular Ca2+ (Cai ) during fertilization in starfish oocytes have been known for long time, little is known precisely about how and what kind of channels are involved during oocyte maturation and in fertilization, and how the mechanisms of changes in Cai in oocytes develop during oocyte maturation. Since in starfish, oocyte maturation-inducing hormone, 1-methyladenine (1MA) is well known, we took advantage of it to investigate the developmental process of channel-function and changes in Cai in three different developmental stages using 1MA. Sperm-induced membrane current at voltage clamp and changes in Cai in starfish oocytes, Asterina pectinifera, were examined in stages of immature, partly mature (a state in 15-20 min after sufficient concentration, 1 µM of 1MA addition, or 30-40 min exposure to subthreshold concentration of 1MA), and mature oocytes (MO). We found some immature and many partly MOs showed fluctuating responses in membrane current, membrane potential, and corresponding changes in Cai , which are distinct from those in MOs. The responses in immature and partly MOs indicate physiologically characteristic responses of insufficient changes in Cai and its corresponding electrical responses at the partial developmental stage during maturation. Our data should shed light on the mechanism of egg activation and oocyte maturation in terms of examining membrane current and corresponding changes in Cai .

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.

Matched comparative study of trifocal bone transport versus induced membrane followed by trifocal bone transport in the treatment of segmental tibial defects caused by posttraumatic osteomyelitis.

OBJECTIVES: To compare the efficacy and clinical outcomes of trifocal bone transport (TBT) versus induced membrane followed by trifocal bone transport (IM + TBT) in the treatment of tibial defects > 6 cm caused by posttraumatic osteomyelitis. METHODS: A total of 69 eligible patients with tibial defects > 6 cm who were treated between January 2010 and January 2018 were retrospectively reviewed. Overall, 18 patients treated by IM + TBT and 18 treated by TBT were matched by propensity score analysis. The mean tibial defect after radical debridement was 6.97 ± 0.76 cm (range, 6.0 to 8.9 cm). The measurements, including demographic data, external fixation index (EFI), external fixation time (EFT), duration of docking union, bone and functional outcomes evaluated by the Association for the Study and Application of the Method of Ilizarov (ASAMI) scoring system, and postoperative complications evaluated by Paley classification during follow-up were recorded. RESULTS: Age, gender, injury mechanism, affected side, defect size, previous operation time, and follow-up time were not significantly different between the two groups (P > 0.05). The mean EFT was 293.8 ± 12.1 days in the TBT group vs. 287.5 ± 15.3 days in the IM + TBT group. The mean EFI was 36.02 ± 2.76 days/cm vs. 34.69 ± 2.83 days/cm, respectively. The mean duration of docking union was 210.7 ± 33.6 days vs. 179.7 ± 22.9 days, respectively. There was no significant difference in postoperative bone and functional results between the two groups. Delayed union or nonunion and soft tissue incarceration were significantly reduced in the IM + TBT group compared to those in the TBT group. CONCLUSION: Both TBT and IM + TBT achieved satisfactory postoperative bone and functional outcomes in patients with segmental tibial defects > 6 cm following posttraumatic osteomyelitis, while IM + TBT had a significantly lower incidence of postoperative complication in delayed union or nonunion and soft tissue incarceration, as well as faster docking union.

Comparison of the clinical outcomes between vascularized bone graft and the Masquelet technique for the reconstruction of Gustilo type III open tibial fractures.

BACKGROUND: Gustilo type III tibial fractures commonly involve extensive soft tissue and bony defects, requiring complex reconstructive operations. Although several methods have been proposed, no research has elucidated the efficacies and differences between vascular bone graft (VBG) and the Masquelet technique (MT) to date. We aimed to evaluate and compare the clinical effectiveness of VBG and the MT for the reconstruction of Gustilo type III tibial fractures. METHODS: This retrospective cohort study enrolled patients who underwent reconstruction for Gustilo type III tibial fractures using VBG or the MT in a single center from January 2000 to December 2020. The patients' demographics, injury characteristics, and surgical interventions were documented for analysis. The clinical outcomes including union status, time to union, postoperative infections, and the causes of union failure were compared between the two groups. RESULTS: We enrolled 44 patients: 27 patients underwent VBG, and 17 underwent MT. The average union time was 20.5 ± 15.4 and 15.1 ± 9.0 months in the VBG and MT groups, respectively (p = 0.232). The postoperative deep infection rates were 70.4% and 47.1% in the VBG and MT groups (p = 0.122), respectively. Though not statistically significant, the VBG group had a shorter union time than did the MT group when the bone defect length was > 60 mm (21.0 ± 17.0 versus 23.8 ± 9.4 months, p = 0.729), while the MT group had a shorter union time than did the VBG group when the bone defect was length < 60 mm (17.2 ± 5.6 versus 10.7 ± 4.7 months, p = 0.067). CONCLUSIONS: VBG and MT are both promising reconstruction methods for Gustilo type III tibial fractures. VBG appears to have more potential in reconstructing larger bone defects, while MT may play an important role in smaller bone defects, severe surgical site infections, and osteomyelitis. Therefore, flexible treatment strategies are required for good outcomes in Gustilo type III open tibial fractures.

Evaluation of the Induced Membrane for Neurotrophic Factors.

PURPOSE: Despite gaining popularity as a bridge for small and moderate nerve gaps, an acellular nerve allograft (ANA) lacks many of the neurotrophic characteristics of a nerve autograft. Pseudomembranes induced to form around temporary skeletal spacers are rich in growth factors. Induced membranes may have beneficial neurotrophic factors which could support ANA. METHODS: Twenty-two male Sprague-Dawley rats underwent resection of 2 cm of the sciatic nerve. A silicone rod was inset in the defect of 11 experimental rats, and marking sutures only were placed in the nerve stumps of the remaining 11 control rats. After allowing 4 weeks for tissue maturation, tissue samples harvested from the induced membrane (experimental group) and the tissue bed (control group) were analyzed using Luminex multiplex assay to quantify differences in detectable levels of the following neurotrophic factors: nerve growth factor, glial-derived nerve factor, vascular endothelial growth factor, and transforming growth factor ß (TGF-ß) 1, 2, and 3, interleukin-1ß, and monocyte chemoattractant protein 1. RESULTS: No difference was detected between the control and experimental groups in levels of vascular endothelial growth factor. Higher levels of TGF-ß1, TGF-ß2, TGF-ß3, glial-derived nerve factor, nerve growth factor, monocyte chemoattractant protein 1, and interleukin-1ß were detected in the experimental group. CONCLUSIONS: In the setting of peripheral nerve injury, an induced membrane has higher levels of several neurotrophic factors that may support nerve regeneration compared to wound bed cicatrix. CLINICAL RELEVANCE: This investigation provides impetus for further study examining the utility of using a staged induced membrane technique in conjunction with delayed nerve grafting in reconstruction of some peripheral nerve defects.

Induced Membrane Technique for the Treatment of Infected Forearm Nonunion: A Retrospective Study.

PURPOSE: Infected forearm nonunion remains a challenge for the hand surgeon. Autologous bone grafting within an induced membrane following implantation of a cement spacer, also known as the Masquelet technique, is a procedure used for addressing segmental bone defects. This report summarized our experience using this technique to treat the infected forearm nonunion. METHODS: We retrospectively reviewed a series of 32 patients treated for infected forearm nonunion by the 2-stage Masquelet technique between 2009 and 2018. There was an infected nonunion of the ulna in 28 patients and an infected nonunion of the radius in 4 patients. All patients had undergone an average of 2.7 procedures before presenting at our institution. Treatment involved a staged procedure in which an antibiotic-impregnated cement spacer was implanted into the bone defect following debridement without internal fixation. It was left in place for 4-6 weeks, during which time a membrane formed around the cement spacer. In the second stage, the induced membrane was incised, and the cement spacer was removed. The defect was then filled with cancellous autograft with the addition of internal fixation. Postoperative radiographs were taken for the evaluation of bone healing. The functional results of the affected forearm were evaluated for motion loss of elbow or wrist and rotation loss of forearm. RESULTS: All nonunions healed without recurrent infection or loosening of internal fixation at the time of final follow-up. All the patients showed substantial functional improvement, with excellent results in 14 patients, satisfactory results in 13, and unsatisfactory results in 5. CONCLUSIONS: The induced membrane technique is an effective solution for infected forearm nonunion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Modified Masquelet technique in children.

Masquelet technique is one of the modalities for the treatment of long bone defect. Using cancellous bone graft to fill the bone defect is always a concern in children due to the small size of their iliac crest and open growth plate. We reported a case of 13-year-old male who presented with gap non-union of middle third of tibia. We applied a modified Masquelet technique by using only the cortical fibular graft instead of cancellous bone to fill the space surrounded by induced membrane. Fibula was used as a nonvascularized strut graft and matched stick graft to achieve complete union. We concluded that nonvascularized fibula grafting is an easy and effective option to fill the bone defect in children in the second stage of Masquelet technique.