The Masquelet technique, also known as the ‘induced membrane technique’ has been utilised in adult reconstruction with varied success. However, there is limited literature on its use in children and this study aims to share our experience. Materials & Methods. Between 2014 and 2022, 7 children underwent bone defect/infection reconstruction using Masquelet technique, four for complications of Congenital Pseudoarthrosis of Tibia (CPT) treatment, two with chronic osteomyelitis and one for Osteogenesis imperfecta with infected nonunion. The length of the defect relative to the length of the bone (index of reconstruction expressed as a percentage), time to union and complications were evaluated with standard radiographs and from electronic medical records. Results. The mean age was 11 years and the procedure was done in five tibiae, one femur and a metatarsal. The mean time interval was 7.1 weeks between the first and second stage surgery. The mean index of reconstruction was 25.8% and the mean follow up period was 17 months. Though six patients achieved union with a mean time to union of 6.5 months (range 4.5 to 10), two patients with multiple previous surgeries for CPT decided to have ablation despite union. The interosseous Masquelet technique of cross synostosis between the tibia and fibula is being highlighted. Conclusions. The Masquelet technique is a reliable method in complex aetiologies and complications that require methodical planning to achieve good results especially in rescue situations of the tibia

The Masquelet technique is a variable method for treating critical-sized bone defects, but there is a need to develop a technique for promoting bone regeneration. In recent studies of bone fracture healing promotion, macrophage-mesenchymal stem cell (MSC) cross-talk has drawn attention. This study aimed to investigate macrophage expression in the induced membrane (IM) of the Masquelet technique using a mouse critical-sized bone defect model. The study involved a 3-mm bone defect created in the femur of mice and fixed with a mouse locking plate. The Masquelet (M) group, in which a spacer was inserted, and the Control (C) group, in which the defect was left intact, were established. Additionally, a spacer was inserted under the fascia of the back (B group) to form a membrane due to the foreign body reaction. Tissues were collected at 1, 2, and 4 weeks after surgery (n=5 in each group), and immunostaining (CD68, CD163: M1, M2 macrophage markers) and RT-qPCR were performed to investigate macrophage localization and expression in the tissues. The study found that CD68-positive cells were present in the IM of the M group at all weeks, and RT-qPCR showed the highest CD68 expression at 1 week. In addition, there was similar localization and expression of CD163. The C group showed lower expression of CD68 and CD163 than the M group at all weeks. The B group exhibited CD68-positive cells in the fibrous capsule and CD163-positive cells in the connective tissue outside the capsule, with lower expression of both markers compared to the M group at all weeks. Macrophage expression in IM in M group had different characteristics compared to C group and B group. These results suggest that the IM differs from the fibrous capsules due to the foreign body reaction, and the macrophage-MSC cross-talk may be involved in Masquelet technique

In a consecutive retrospective analysis of 190 patients treated with the Masquelet technique at the BG Klinikum Hamburg from January 2012 to January 2022, defect-specific features such as the extent and morphology of the defect were recorded, and their influence on the time to reach full weight-bearing of the affected limb was investigated. A total of 217 defects were treated in 190 patients using the Masquelet technique. 70% of all defects were located in the tibia, followed by 22% in the femur and only about 7% in the upper extremity. The average length of all defects was 58 mm (+/−31 mm), with the largest defect measuring 180 mm and the smallest measuring 20 mm. 89% of the patients achieved full weight-bearing at the end of therapy. The average time from initiation of therapy to reaching safe full weight-bearing was 589 days. There was a significant correlation between defect length and time to reach full weight-bearing (p = 0.0134). These results could serve as a basis for creating a score for prognostics and evaluation of bone healing after treatment with the Masquelet technique. Additionally, the results could help guide indications for secondary stabilization using internal fixation

Recent researches indicate that both M1 and M2 macrophages play vital roles in tissue repair and foreign body reaction processes. In this study, we investigated the dynamics of M1 macrophages in the induced membrane using a mouse femur critical-sized bone defect model. The Masquelet method (M) and control (C) groups were established using C57BL/6J male mice (n=24). A 3mm-bone defect was created in the right femoral diaphysis followed by a Kirschner wire fixation, and a cement spacer was inserted into the defect in group M. In group C, the bone defect was left uninserted. Tissues around the defect were harvested at 1, 2, 4, and 6 weeks after surgery (n=3 in each group at each time point). Following Hematoxylin and eosin (HE) staining, immunohistochemical staining (IHC) was used to evaluate the CD68 expression as a marker of M1 macrophage. Iron staining was performed additionally to distinguish them from hemosiderin-phagocytosed macrophages. In group M, HE staining revealed a hematoma-like structure, and CD68-positive cells were observed between the spacer and fibroblast layer at 1 week. The number of CD68-positive cells decreased at 2 weeks, while they were observed around the new bone at 4 and 6 weeks. In group C, fibroblast infiltration and fewer CD68-positive cells were observed in the bone defect without hematoma-like structure until 2 weeks, and no CD68-positive cells were observed at 4 and 6 weeks. Iron staining showed hemosiderin deposition in the surrounding area of the new bone in both groups at 4 and 6 weeks. The location of hemosiderin deposition was different from that of macrophage aggregation. This study suggests that M1 macrophage aggregation is involved in the formation of induced membranes and osteogenesis and may be facilitated by the presence of spacers

Aim. infected segmental bone defect (ISBD) is frequent in developing countries. The aim of this study was to assess the efficacy of the Masquelet technique in the treatment of ISBD in a low-resource setting. Patients and Method. We performed a prospective cohort study during the period from 2018 to 2022. Patients with infected bone defect of long bones were included. Management protocol consisted of two stages in all patients. The first stage consisted in debridement, tissues biopsy for microbiological culture, stabilization with external fixator and defect filling with gentamicin cement spacer. The second stage consisted of reconstruction using a cancellous bone autograft alone, or a mixture of autograft with allograft (demineralized bone matrix + tricalcium phosphate) and 1 gram of vancomycin powder. All patients were followed-up for at least one year. The results were assessed based on both objective (clinical and radiographic evaluation) and subjective (limb function and patient satisfaction) criteria. Main outcomes were bone union, reoperation and failure rates, union time, and limb function. Results. We included 31 patients in this study (80.6% men), with a median age of 35 [9 – 80] years. The tibia was affected in 12 cases and the femur in 15 cases. The median size of bone defect was 4 [1.5 – 12] cm. The most prevalent microorganisms were Klebsiella pneumoniae and Staphylococcus aureus. The mean interval between both stages was 14 (8 – 36) weeks and the median follow-up period after the second stage was 20 [12-62] months. External fixation was used in both stages in 25(80%) cases. Bone union was achieved in 26 (83.8%) patients of whom 24 without recurrence of infection, over a median time of 9 [6 – 16] months. All patients with a mixed graft (allograft and autograft) impregnated with local antibiotics achieved bone union. Two patients needed reoperation for relapse of infection between both stages, and subsequently achieved bone union without recurrence of infection. There were three cases of failure related to persistent infection or insufficient fixation stability in the second stage. Conclusions. Masquelet technique is a reliable procedure that can be safely performed in limited resources settings with satisfactory results. The mixture of autograft and allograft when available, all mixed with vancomycin seems to give promising results

Aim. Which patients is bone-defect-reconstruction with the Masquelet-technique suitable and which problems did we see?. Method. From 11/2011 to 4/2016 we treated 49 Patients (12f/37m) with bone-defects up to 150mm after septic complications with the Masquelet-technique. We had infected-non-unions of upper and lower extremity, chronic osteomyelitis, infected knee-arthrodesis and upper-ancle-empyema. On average the patients were 48 (8–74) years old. The mean bone-defect-size was 60 mm (25–150). From other hospitals came 47 of the 49 patient, where they had up to 20 (mean 4,9) operations caused by the infection. The time before transfer to our hospital was on average 177days (6–720). 40 patients receaved flaps because of soft tissue-defects (12 free flaps, 28 local flaps). 21 patients suffered a polytrauma. In 8 cases the femur, in 4 cases a knee-arthrodesis, in 34 cases tibia, in 2 cases humerus and in 1 case the ulna were infected resulting in bone defects. Indication for the Masquelet-technique was low-/incompliance in 35 cases due to higher grade of traumatic brain injury and polytrauma and difficult soft-tissue conditions, in 9 times problems with segment-transport and in 5 cases as dead space management. Positive microbial detection succeeded in 32 patients at the first operation. Mainly we found difficult to treat bacteria. After treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with antibiotic loaded cement spacer and external fixation we removed the spacer6–8 weeks later and filled the defect with bone graft. In 23 cases we stabilized the defect then with an internal angle stable plate. All patients were examined clinically and radiologically every 4–6 weeks in our outpatient-department until full weight bearing, later every 3 months. Results. In 41 of 49 cases the infection was clinically treated successfully. 21 patients are allowed for full weight bearing (all with secondary internal plates). There were 8 recurrences of infection, 22 instabilities needing internal stabilization and further bone graft. We saw “Plate-breaks” in 4 cases. 2 patients underwent amputation. Conclusions. For patients with low-/incompliance for various reasons and for those with difficult soft tissue conditions following flaps the Masquelet technique is a valuable alternative to the normal bone graft and to the segment transport. The stiffness of the new Masquelet bone like a rod is a problem. Internal fixation is often necessary

The clinical case refers to a male patient, 34 years old, admitted at the Emergency Department after a fall of 2 meters. Of that trauma, resulted an exposed Monteggia fracture type III – Gustillo & Anderson IIA – on his left arm. With this work, the authors intend to describe the evolution of the patient's clinical condition, as well as the surgical procedures he was submitted to. The authors used the patient's records from Hospital's archives, namely from the Emergency Department, Operating Room, Infirmary and Consultation, and also the diagnostic exams performed throughout the patient's clinical evolution. The clinical case began in December 2011, when the patient suffered a fall of 2 meters in his workplace. From the evaluation in the Emergency Department, it was concluded that the patient presented, at the left forearm, an exposed Monteggia type III fracture – Gustillo & Anderson IIA – combined with a comminuted fracture of the radial head. At the admission day, the wound site was thoroughly rinsed, the fracture was reduced and immobilized with an above-the-elbow cast, and antibiotics were initiated. Six days after admission, the patient was submitted to open reduction with internal fixation with plate and screws of the fracture of the ulna and radial head arthroplasty. The postoperative period was uneventful. Two months after the surgical procedure, inflammatory signals appeared with purulent secretion in the ulnar suture. Accordingly, the patient was submitted to fistulectomy, rinsing of the surgical site and a cycle of antibiotics with Vancomycin, directed to the S. aureus isolated from the purulent secretion. The clinical evolution was unfavorable, leading to the appearance of a metaphyseal pseudarthrosis or the ulna and dislocation of the radial head prosthesis. The previously implanted material was therefore removed, 4 months after the traumatic event; at the same time an external fixation device was applied and the first part of a Masquelet Technique was conducted. The second part of the aforementioned procedure was carried out in December 2012. The patient was discharged from the consultation after a 2 years follow-up, with a range of motion of the left elbow acceptable for his daily living activities. In spite of the multiple surgical rinsing procedures and directed antibiotics, the development of a metaphyseal pseudarthrosis of the ulna was inevitable. This clinical case illustrates how the Masquelet Technique presents itself as a good solution for the cases of non-union of fractures in the context of infection

For which patients is bone-defect-reconstruction with the Masquelet-technique suitable?. Between 11/2011 and 1/2015 we treated 27 Patients (4 female/ 23 male) with bone-defects up to 150mm after septic complications with the Masquelet-technique. Reason of the bone defects were infected-non-unions of lower extremity, chronic osteomyelitis, infected knee-arthrodesis, chronic upper-ancle-empyema and infect-defect-non-union of the humerus. On average the patients were 47,5 (18–74) years old. The mean bone-defect-size was 62,6 mm (25–150). 26 of the 27 patients came from other hospitals, where they had up to 20 (mean 4,9) operations caused by the infection. The time before transfer to our hospital was on average 177days (6–720). 25 patients receaved flaps because of soft tissue-defects (7 free flaps, 18 local flaps). 13 patients suffered a polytrauma. In 5 cases the femur, in 3 cases a knee-arthrodesis, in 18 cases the tibia and in 1 case the humerus was affected by infection resulting in bone defects. Indication for the Masquelet-technique was low-/incompliance in 10 cases due to higher grade of traumatic brain injury and polytrauma and difficult soft-tissue conditions, in 6 times after problems with segment-transport and in 1 case as dead space management. Positiv microbial detection succeeded in 19 patients at the first operation although most of the patients underwent long term antibiotic therapy. Mainly we found problematic bacteria. At the time of defect reconstruction with spongious graft we found persistant bacteria in 4 cases. The first operation aimed treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with an antibiotic loaded cementspacer as well as external fixation. 6–8 weeks later we removed the spacer and filled the defect with autologous bonegraft. In 2 cases we needed 2 bone grafts to fill the defect. In 9 cases we removed the fixateur and stabilized the defect with an internal anglestable plate. All patients were examined clinically and radiologically every 4–6 weeks in our outpatient-department for osteitis until full weight bearing and later every 3months. In 22 of 27 cases the infection was clinically treated successfully. 5 patients are allowed for full weight bearing (all with secondary internal plates). No patient underwent amputation. There were 4 recurrences of infection, 9 instabilities needing internal stabilization and further bonegraft. For patients with low-/incompliance for various reasons and for those with difficult soft tissue conditions following flaps the Masquelet technique is a valuable alternative to the normal autologious spongegraft and to the segmenttransport. Internal fixation seems necessary

We hypothesise that the Masquelet induced membrane used for the reconstruction of large bone defects were likely to involve mesenchymal stem cells (MSCs), given the excellent resultant skeletal repair. This study represents the first characterisation in humans of the induced membrane formed as a result of the Masquelet technique. Methods. Induced membranes and matching periosteum were harvested from 7 patients. Cytokines (BMP2, VEGF, SDF1) and cell lineage markers (CD31, CD271, CD146) were studied by immunohistochemisty. Flow cytometry was used to measure the cellularity and cellular composition. MSCs were enumerated using a colony forming unit fibroblast assay. In expanded cultures, a 96-gene array card was used to assess their transcriptional profile. Alkaline phophatase, alizarin red and calcium assays were employed to measure their in vitro osteogenic potential. Results. Membrane was more cellular(p=0.028), had more MSC phenotype(p=0.043) compared to matched periosteum. The molecular profiles were similar, except for 2-fold abundance of SDF-1 in membrane (p=0.043)compared to periosteum. Membrane and periosteum had a similar proportion of endothelial cells and CFU-F colonies; expanded MSCs from both sources were highly osteogenic. Discussion. These results indicate that the induced membrane possesses a rich source of MSC and therefore our findings support the view that the induced membrane plays an active role in bone regeneration

Aim. For which patients is bone defect reconstruction with the Masquelet-technique after the treatment of osteomyelitis suitable and which results did we have. Methods. From 11/2011 to 4/2018 we treated 112 Patients (36f, 76m) with bone defects up 150mm after septic complications with the Masquelet-technique. We had infected-non-unions of upper and lower extremity, chronic osteomyelitis, infected knee-arthrodesis and knee- and ankle-joint-empyema. On average the patients were 52 (10–82) years old. The mean bone defect size was 48 mm (15–150). Most of our patients came from other hospitals, where they had up to 20 (mean 5.1) operations caused by the infection. Time before transfer in our hospital was on average 7,1 months (0,5–48). 77 patients received free (25) or local (52) flaps because of soft tissue-defects. 58 patients suffered a polytrauma. In 23 cases femur, in 4 cases a knee arthrodesis, in 68 cases tibia, in 1 case foot, 6 times ankle-joint arthrodesis, in 6 cases humerus, in 4 cases forearm were infected resulting in bone defects,. In most cases the indication for the Masquelet-technique was low-/incompliance due to higher grade of brain injury and polytrauma followed by difficult soft tissue conditions and problems with segmenttransport. In 2/3 positive microbial detection succeeded at the first operation. Mainly we found difficult to treat bacteria. After treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with antibiotic loaded cementspacer and external fixation we removed the spacer in common 6–8 weeks later and filled the defect with autologeous bone graft. Most of the patients needed an internal fixation after removing of the fixex. All patients were examined clinically and radiologically every 4–6 weeks in our outpatient department until full weight bearing, later every 3 Months. Results. in 93 of 112 cases the infection was clinically treated successful. 48 patients are allowed full weight bearing (45 with secondary internal plates). There were 18 recurrences of infection, 3 patients underwent lower limb amputation. Conclusions. For patients with low-/incompliance for various reasons and for those with difficult soft tissue conditions following flaps the masquelet technique is a valuable alternative to normal bone graft or segmenttransport. The stiffness of the new masquelet-bone as a rod seems a problem and internal fixation is necessary

A high volume of trauma and limited resources means that traditional methods of bone reconstruction are not feasible in parts of Africa. We present the management and outcomes of using Masquelet's concept, of an induced membrane and secondary morcellised cancellous bone grafting, in patients with severe lower limb trauma. Eleven patients were treated in an orthopaedic department in rural southern Africa between 2011 and 2012. This is a subgroup that is part of a larger study of open fractures that received ethical approval. All patients were male, with ten aged between 20 and 35 and one aged 70. Two were HIV positive. There were three open femur and eight open tibia fractures. Three required fasciocutaneous flaps and one required a muscle flap to achieve adequate soft tissue coverage. Eight cases were performed as the primary treatment and three were to treat septic non-unions. Bone defects ranged from 4 to 10 cm. Definitive bony stabilisation was maintained by mono-lateral external fixator in three patients. In other cases this was converted to a circular frame or internal fixation. The results have been mixed. In three patients bone grafting was delayed due to wound or pin site problems. In one case the bone graft was lost due to infection but repeating the procedure produced a good result. Time to bony union in each case is difficult to quantify. However, there is clear evidence of new bone forming in most cases. Four patients are weight bearing with external fixation removed, as are five patients with internal fixation. In a few cases bony union appears to be taking significantly longer, if at all. Masquelet technique is a welcome addition to the options available in bone reconstruction. However, time to achieve bony union is unpredictable. Refinement of the technique for use in the developing world is needed

The Masquelet or induced membrane technique (IMT) is a two-stage surgical procedure used for the treatment of segmental bone defects. In this technique, the defect is first filled with a polymethyl methacrylate (PMMA) spacer, which triggers the formation of a membrane that will encapsulate the defect. During the second surgery, the spacer is carefully removed and replaced by autologous bone graft while preserving the membrane. This membrane is vascularized, contains growth factors, and provides mechanical stability to the graft, all of which are assumed to prevent graft resorption and promote bone healing. The technique is gaining in popularity and several variations have been introduced in the clinical practice. For instance, orthopaedic surgeons now often include antibiotics in the spacer to treat or prevent infection. However, the consequences of this approach on the properties of the induce membrane are not fully understood. Accordingly, in a small animal model, this study aimed to determine the impact on the induced membrane of impregnating spacers with antibiotics frequently used in the IMT. We surgically created a five-mm segmental defect in the right femur of 25 adult male Sprague Dawley rats. The bone was stabilized with a plate and screws before filling the defect with a PMMA spacer. Animals were divided into five equal groups according to the type and dose of antibiotics impregnated in the spacer: A) no antibiotic (control), B) low-dose tobramycin (1.2 g/40 g of PMMA), C) low-dose vancomycin (1 g/40 g of PMMA), D) high-dose tobramycin (3.6 g/40 g of PMMA), E) high-dose vancomycin (3 g/40 g of PMMA). The animals were euthanized three weeks after surgery and the induced membranes were collected and divided for analysis. We assessed the expression of selected genes (Alpl, Ctgf, Runx2, Tgfb1, Vegfa) within the membrane by quantitative real-time PCR. Moreover, frozen sections of the specimens were used to quantify vascularity by immunohistochemistry (CD31 antigen), proliferative cells by immunofluorescence (Ki-67 antigen), and membrane thickness. Microscopic images of the entire tissue sections were taken and analyzed using FIJI software. Finally, we measured the concentration of vascular endothelial growth factor (VEGF) in the membranes by ELISA. No significant difference was found among the groups regarding the expression of genes related to osteogenesis (Alpl, Runx2), angiogenesis (Vegfa), or synthesis of extracellular matrix (Ctgf, Tgfb1) (n = four or five). Similarly, the density of proliferative cells and blood vessels within the membrane, as well as the membrane thickness, did not vary substantially between the control, low-dose, or high-dose antibiotic groups (n = four or five). The concentration of VEGF was also not significantly influenced by the treatment received (n = four or five). The addition of tobramycin or vancomycin to the spacer, at the defined low and high doses, does not significantly alter the bioactive characteristics of the membrane. These results suggest that orthopaedic surgeons could use antibiotic-impregnated spacers for the IMT without compromising the induced membrane and potentially bone healing

Aim. The induced membrane technique (IMT) or Masquelet technique is a two-step surgical procedure used to treat bony defects (traumatic or resulting from tumoral resections) and pseudo arthroses, even caused by infections. The relatively small case series reported, sometimes with variants to the original technique, make it difficult to assess the real value of the technique. Aim of this study was then to undertake a systematic review of the literature with a particular focus on bone union, infection eradication and complication rates. Method. A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Individual Patient Data (PRISMA-IPD) guidelines. PubMed and other medical databases were searched using “Masquelet technique” and “induced membrane technique” keywords. English, French or Italian written articles were included if dealing with IMT employed to long bones in adults and reporting at least 5 cases with a 12 months minimum follow-up. Clinical and bone defect features, aetiology, surgical data, complications, re-interventions, union and infection eradication rates were recorded into a database. Fischer's exact test and unpaired t-test were used for the statistical analysis on the individual patient's data. Results. Ten papers met the inclusion criteria (312 patients), but only 5 reported individual patients data (65 cases). IMT was used for acute bone loss (53%), septic (47%) and aseptic (7%) pseudo arthroses and tumour resections (2%). Bone defect length ranged from 0.6 to 26 cm. Overall, union rate was achieved in 88% of the cases and infection cured in 93%. Complication rate was 53%. Surgical variants included the use of antibiotic-loaded spacers (59.9%), internal fixation during the first step (62.1%), use of Reamer-Irrigator-Aspirator technique (40.1%) instead of iliac crest (63.1%) grafting, bone substitutes (18.3%) and growth factors addition (41%). No statistical differences were found comparing patient-related factors or surgical variants in achieving the two outcomes. Conclusions. IMT is effective to achieve bone union and infection eradication, but is associated with a high rate of complications and re-interventions. This should be taken into consideration by the surgeons and be a part of the informed consent. This systematic review was limited by the few studies meeting the inclusion criteria and their high variability in data reporting, making a meta-analysis impossible to undertake. Further studies are needed to demonstrate the role the patients’ clinical features and IMT variants with respect to bone union and infection eradication

This work refers to a male patient, 25 years of age, admitted in the Emergency Department following a bicycle accident, of which resulted an open fracture of the right forearm bones – Gustillo & Anderson I. With this work, the authors have as objective the description of the patient's clinical condition – starting with the fracture, over to the osteomyelitis – as well as the surgical procedures and remaining treatments he was submitted to. The authors used the patient's records from Hospital's archives, namely records from the Emergency Department, Operating Room, Infirmary and Consultation, and also the diagnostic exams performed throughout the patient's clinical evolution. This clinical case began in May 2013, when the patient suffered an open fracture of the right forearm bones – Gustillo & Anderson I – due to a bicycle accident. At the time, the exposure site was thoroughly rinsed, a cast immobilization was made, and antibiotics were prescribed. In the fifth day following the trauma, the patient was submitted to an open reduction with internal fixation with plate and screws of both forearm bones. In the following period, the distal segment of the suture suffered necrosis, exposing the radial plate and the tendons of the first dorsal compartment. The Plastic Surgery team was then contacted, proposing the execution of a graft over the exposed area, which was made in August 2013. In the postoperative period, about half the graft lost its viability and it was noted that a radial pseudoarthrosis had developed – in the context of osteomyelitis – with a defect of about 9 centimeters. This condition prompted the extraction of the osteosynthesis material, about 4 months after its application, and at the same time the first stage of a Masquelet Technique was performed. The second stage of the aforementioned procedure was carried out two months later. Currently, the patient is clinically stable, with right hand mobility acceptable for his daily living activities. Analyzing the patient's clinical evolution, we concluded that, even though the adequate therapeutic decisions have been made in each stage, the development of osteomyelitis was inevitable. This realization, in association with the patient's young age, raises debatable questions of therapeutic order

Purpose of the study: The objective of this study was to establish an experimental sheep model for a surgical procedure which has been clinically successful for repairing major loss of bone stock: the Masquelet technique. Material and methods: A 25 mm bone defect was created in a metatarsal bone then filled with a cement filler. After six weeks, the cement was removed after opening the neoformed pseudosynovial membrane. The cavity was left empty in group 1 (n=6) or filled with a morcelized cancellous autograft harvested from the iliac crests in group 1 (n=6). Results: The surgery was well tolerated in all animals which were able to used the injured limb the day after the operation. Radiographic images and histological findings 24 weeks after surgery demonstrated that healing had not been achieved in all of the animals in group 1. Inversely, healing was achieved in all animals in group 2 at 24 weeks. Immunohistochemistry of the neoformed pseudosynovial demonstrated :. an abundant vascular network,. presence of cells expressing transcription factor CBFA1,. very few inflammatory CD14+ cells (macrophages),. an extracellular matrix positive for type I collagen. Conclusion: The sheep metatarsal model is a model of critical size with low morbidity. This model could be used to:. evaluate new therapeutic strategies for bone regeneration in conditions close to clinical situations,. study the role of the membrane in bone repair. The presence of a pseudosynovial membrane might:. be a barrier against the diffusion of bone morphogenetic proteins outside the lesion and. potentially be a reservoir of stem and vascular cells which could be useful for new technologies

Previous clinical studies have shown the efficacy of a foreign body-induced membrane combined with bone autograft for the reconstruction of traumatologic or pathologic large bone defects or, bone non union. This membrane, rich in mesenchymal stromal cells (MSC), avoids bone autograft resorption and promotes consolidation by revascularisation of the bone and secretion of growth factors. Reconstruction requires two different surgical stages: firstly, insertion of a cement spacer in the defect, and secondly, removal of the spacer, preservation of the foreign body-induced membrane and filling of the cavity by bone autograft. The optimal time to perform the second surgical stage remains unclear.

So, we aimed to correlate bone healing and, phenotype and function of cells isolated from the induced membrane, in patients whose second surgery was performed on average after 6 months (i.e. beyond the recommended time of one month). Cell phenotype was determined by flow cytometry and cell function by: alkaline Phosphatase enzyme activity, secretion of calcium and von Kossa staining. Second, using histological and immunohistochemistry studies, we aimed to determine the nature and function of induced membrane over time. Seven patients were included with their consent.

Results showed Treated patients achieved in all cases bone union (except for one patient) and in in vitro and histology and immunohistochemistry gave some indications which need to be completed in the future. First, patient age seemed to be an indicator of bone union speed and recurrent infection, appeared to influence in vitro MSC osteogenic potential and induced membrane structure. Second, we reported, in bone repair situation, the commitment over time in osteogenic lineage of a surprising multipotent tissue (induced membrane) able of vascularisation/ osteogenesis/ chondrogenesis at a precocious time. Finally, best time to perform the second stage (one month) could be easily exceeded since bone union occurred even at very late times.

Aims. Musculoskeletal infection is a devastating complication in both trauma and elective orthopaedic surgeries that can result in significant morbidity. Aim of this study was to assess the effectiveness and complications of local antibiotic impregnated dissolvable synthetic calcium sulphate beads (Stimulan Rapid Cure) in the hands of different surgeons from multiple centres in surgically managed bone and joint infections. Methods. Between January 2019 and December 2022, 106 patients with bone and joint infections were treated by five surgeons in five hospitals. Surgical debridement and calcium sulphate bead insertion was performed for local elution of antibiotics in high concentration. In all, 100 patients were available for follow-up at regular intervals. Choice of antibiotic was tailor made for each patient in consultation with microbiologist based on the organism grown on culture and the sensitivity. In majority of our cases, we used a combination of vancomycin and culture sensitive heat stable antibiotic after a thorough debridement of the site. Primary wound closure was achieved in 99 patients and a split skin graft closure was done in one patient. Mean follow-up was 20 months (12 to 30). Results. Overall, six out of 106 patients (5.6%) presented with sepsis and poorly controlled comorbid conditions, and died in the hospital within few days of index surgery. Out of the remaining 100 patients, control of infection was achieved in 95 patients (95%). Persistence of infection was noted in five (5%) patients. Out of these 95 patients that had good control of infection, four patients (4.2%) with gap nonunion needed Masquelet procedure to achieve union. Conclusion. Our multicentre experience confirmed that surgical debridement along with calcium sulphate bead insertion was effective in treating bone and joint infections without any side effects and complications. Cite this article: Bone Jt Open 2023;4(7):516–522

The need for an artificial scaffold in very large bone defects is clear, not only to limit the risk of graft harvesting, but also to improve clinical success. The use of custom osteoconductive scaffolds made from biodegradable polyester and ceramics can be a valuable patient friendly option, especially in case of a concomitant infection. Multiple types of scaffolds for the Masquelet procedure (MP) are available, however these frequently demonstrate central graft involution when defects exceed a certain size and the complication rates remains high. This paper describes three infected tibial defect nonunions with a segmental defect over ten centimeters long treated with a customized 3D printed polycaprolactone-tricalcium phosphate (PCL-TCP) cage in combination with biological adjuncts. Three male patients, between the age of 37 and 47, were treated for an infected tibial defect nonunion after sustaining Gustilo grade 3 open fractures. All had a segmental midshaft bone defect of more than ten centimeters (range 11–15cm). First stage MPs consisted of extensive debridement, external fixation and placement of anterior lateral thigh flaps (ALT). Positive cultures were obtained from all patients during this first stage, that were treated with specific systemic antibiotics during 12 weeks. The second stage MP was carried out at least two months after the first stage. CT scans were obtained after the first stage to manufacture defect-specific cages. In the final procedure a custom 3D printed PCL-TCP cage (Osteopore, Singapore) was placed in the defect in combination with biological adjuncts (BMAC, RIA derived autograft, iFactor and BioActive Glass). Bridging of the defect, assessed at six months by CT, was achieved in all cases. SPECT-scans 6 months post-operatively demonstrated active bone regeneration, also involving the central part of the scaffold. All three patients regained function and reported less pain with full weight-bearing. This case report shows that 3D printed PCL-TCP cages in combination with biological adjuncts is a novel addition to the surgical treatment of very large bone defects in (infected) posttraumatic nonunion of the tibia. This combination could overcome some of the current drawbacks in this challenging indication

Introduction. Treatment of non-union in open tibial fractures Gustilo-Anderson(GA)-3A/3B fractures remains a challenging problem. Most of these can be dealt using treatment methods that requires excision of the non-union followed by bone grafting, masquelet technique, or acute shortening. Circular fixators with closed distraction or bone transport also remains a useful option. However, sometimes due to patient specific factors these cannot be used. Recently antibiotic loaded bone substitutes have been increasingly used for repairing infected non-unions. They provide local antibiotic delivery, fill dead space, and act as a bone conductive implant, which is resorted at the end of a few months. We aimed to assess the outcome of percutaneous injection of bone substitute while treating non-union of complex open tibial fractures. Materials & Methods. Three cases of clinical and radiological stiff tibial non-union requiring further intervention were identified from our major trauma open fracture database. Two GA-3B cases, treated with a circular frame developed fracture-related-infection(FRI) manifesting as local cellulitis, loosened infected wires/pins with raised blood-markers, and one case of GA-3A treated with an intramedullary nail. At the time of removal of metalwork/frame, informed consent was obtained and Cerament-G. TM. (bone-substitute with gentamicin) was percutaneously injected through a small cortical window using a bone biopsy(Jamshedi needle). All patients were allowed to weight bear as tolerated in a well-fitting air-cast boot and using crutches. They were followed up at 6 weekly intervals with clinical assessment of their symptoms and radiographs. Fracture union was assessed using serial radiographs with healing defined as filling of fracture gap, bridging callus and clinical assessment including return to full painless weight bearing. Results. Follow-up at 6 months showed all fractures had healed with no defect or gaps with evidence of new trabecular bone and significant resorption of Cerament-G. TM. at final follow-up. There was no evidence of residual infection with restoration of normal limb function. Fractures with no internal fixation showed a mild deformity that had developed during the course of the healing, presumed due to mild collapse in the absence of fixation. These were less than 10 degrees in sagittal and coronal planes and were clinically felt to be insignificant by the patients. Conclusions. Cerament-G's unique combination of high dose antibiotics and hydroxy apatite matrix provided by calcium sulphate might help provide an osteoconductive environment to allow these stiff non-unions to heal. The matrix appears to provide a scaffold-like structure that allows new bone in-growth with local release of antibiotics helping reduce deep-seated infections. The final deformation at fracture site underlines the need for fixation- and it is very unlikely that this technique will work in mobile nonunions. Whilst similar fractures may heal without the use of bone substitute injections, the speed of healing in presence of significant fracture gap suggests the use of these bone substitutes did help in our cases. Further studies with a larger cohort, including RCTs, to evaluate the effectiveness of this technique compared to other methods are needed

Treatment of large bone defects represents a great challenge for orthopedic surgeons. The main causes are congenital abnormalities, traumas, osteomyelitis and bone resection due to cancer. Each surgical method for bone reconstruction leads its own burden of complications. The gold standard is considered the autologous bone graft, either of cancellous or cortical origin, but due to graft resorption and a limitation for large defect, allograft techniques have been identified. In the bone defect, these include the placement of cadaver bone or cement spacer to create the ‘Biological Chamber’ to restore bone regeneration, according to the Masquelet technique. We report eight patients, with large bone defect (for various etiologies and with an average size defect of 13.3 cm) in the lower and upper limbs, who underwent surgery at our Traumatology Department, between January 2019 and October 2020. Three patients were treated with both cortical and cancellous autologous bone grafts, while five received cortical or cement spacer allografts from donors. They underwent pre and postoperative radiographs and complete osseointegration was observed in all patients already undergoing monthly radiographic checks, with a restoration of length and range of motion. In our study, both the two stage-Masquelet and the cortical bone graft from a cadaver donor proved to be valid techniques in patients with very extensive defects to reconstruct the defect, restore the length, minimize implant left in situ and achieve complete functional recovery