Cement Spacer Research Articles

Creation of a Custom-Length, Humeral Antibiotic Cement Spacer for Use in Treatment of Shoulder Periprosthetic Joint Infection

Periprosthetic joint infection of the shoulder is a challenging clinical situation to manage owing to the fastidious organisms often present and delayed clinical presentation. While several treatment options have been described, the mainstay of treatment remains a staged revision with the use of a humeral antibiotic cement spacer. Such spacers are commercially available or can be made by hand. When an extended humeral osteotomy is required to remove a well-fixed long stem humeral component, it may be advantageous to place an antibiotic spacer with a stem length approximately as long as the hardware being removed. This technique demonstrates creation of a custom length, humeral antibiotic cement spacer for use in treatment of shoulder periprosthetic joint infection.

A Cost-effective 3D Printed Antibiotic Spacer for Management of Periprosthetic Joint Infection of the Knee: A Case Report

Introduction: The 3-dimensional (D) printed customized bone cement spacer molds provide a single solution to various difficulties faced during the first stage of 2-stage exchange revision knee arthroplasty in periprosthetic joint infection. Materials and Methods: A 60-year-old lady presented with periprosthetic joint infection of the knee. The spacer molds were designed using computer-aided-design (CAD) software and intraoperatively antibiotic spacer was formed after assessing the bone gaps at a very low price ($100). Results: The infection was eradicated for over 3 months. The spacer was designed perfectly to the bone gaps and bone defects leading to proper gap balancing and wound closure. Conclusions: The CAD-articulating spacer helps to reduce the complexity of the surgical procedure. 3D printing provides a cost-effective measure to tackle such complex surgeries. The CAD-articulating spacer gives a futuristic guiding tool using 3D printing to make the surgery easier and more effective.

Masquelet's induced membrane technique: Review of current concepts and future directions.

Masquelet's induced membrane technique (MIMT) is a relatively new, two-stage surgical procedure to reconstruct segmental bone defects. First performed by Dr. Masquelet in the mid-1980s, MIMT has shown great promise to revolutionize critical-sized bone defect repair and has several advantages over its alternative, distraction osteogenesis (DO). Also, its success in extremely challenging cases (defects > 15 cm) suggests that its study could lead to discovery of novel biological mechanisms that might be at play during segmental defect healing and fracture non-union. MIMT's advantages over DO have led to a world-wide increase in MIMT procedures over the past decades. However, MIMT often needs to be repeated and so the average initial success rate in adults lags significantly behind that of DO (86% vs 95%, respectively). The autologous foreign-body membrane created during the first stage by the immune system's response to a polymethyl methacrylatebone cement spacer is critical to supporting the morselized bone graft implanted in the second stage. However, the biological and/or physical mechanisms by which the membrane supports graft to bone union are unclear. This lack of knowledge makes refining MIMT and improving the success rates through technique improvements and patient selection a significant challenge and hinders wider adoption. In this review, current knowledge from basic, translational, and clinical studies is summarized. The dynamics of both stages under normal conditions as well as with drug or material perturbations is discussed along with perspectives on high-priority future research directions.

Customized intraoperatively molded articulating cement spacers for two-stage revisions TKA with major bone defects.

The use of articulating spacers, molded or prefabricated, becomes difficult in case of severe bone losses. Our idea was to customize the Molded Articulating Cement Spacers with cement stem extensions and if necessary metaphyseal cement augmentations in order to use them also in case of major bone defects. Fifty-four knees in fifty-three patients undergoing 2-stage exchange arthroplasty were divided in 4 groups, treated with 4 different types of spacers (Static, articulating molded, customized molded and metal on Poly) and evaluated in terms of Range of Motion (ROM), Knee Society Score (KSS), patients' related outcome measures (PROMs), rate of complication and ease of the surgical exposure at the time of reimplantation. At final follow-up, no statistical differences in terms of ROM and KSS were found between the articulating groups. Static Spacers showed statistically significant lower results both in terms of ROM and KSS comparing to the other 3 groups (P < 0.05). Considering PROMs, statistically better outcomes for all articulating spacers were found both when spacer was in place and at final follow-up comparing to the static spacers group (P < 0.05). No statistically significant difference was found between the 3 articulating spacers groups. Radiographic analysis did not show signs of loosening, migration or major bone loss. Customized Intraoperatively Molded Articulating Cement Spacers are a safe solution for two-stage revisions TKA with major bone defects and may provide a better quality of life for patients when in place comparing to static ones.

The Influence of Cement Spacer Thickness on Retentive Strength of Monolithic Zirconia Crowns Cemented with Different Luting Agents (A Comparative in-vitro Study)

Aims of Study: to evaluate and compare the retentive strength and the failure-modes of monolithic zirconiacrowns with different cement spacer thickness, cemented with two different types of luting agents.Materials and Methods: Forty sound maxillary first premolar teeth were divided into two main groups(n=20): Group A: cement spacer thickness of 80?m; Group B: cement spacer thickness of 120?m. Thegroups were further subdivided into two subgroups (n=10): (A1, B1) cemented with Panavia F2.0 resincement; (A2, B2) cemented with Riva luting plus RMGIC. All the teeth were prepared to receive monolithiczirconia crowns with the following features: (6º convergence angle, 0.8mm deep chamfer finishing line,4mm axial wall height with planar occlusal reduction). Afterwards, the teeth were scanned and the crownswere fabricated and cemented. Zirconia crowns were pulled-out along its path of insertion using universaltesting machine. Failure stresses were calculated in MPa. Failure-modes was assessed using magnifyinglens (2.5X).Results: The highest mean retentive values (in Mpa) was recorded by subgroup B1 (8.651); followed bysubgroup B2 (7.765); subgroup A1 (7.309) and subgroup A2 (6.875). Independent t-test showed a statisticallysignificant difference between A1 and B1 subgroups. Concerning the failure-mode, the majority of samplesrevealed adhesive failure between teeth and cement.Conclusion: All the tested crowns have mean retentive values within the clinically acceptable limit,increasing cement space resulted in a significant increase in the retention when Panavia F2.0 used as a lutingagent, while, it has no significant effect on the retention when RIVA luting plus was used.

Mechanical Safety Study and Antibiotic-loaded Polymethylmethacrylate Spacers Threshold, Manufactured Intraoperatively, in Orthopaedic Surgery

The study performed the biomechanical testing of polymethylmethacrylate (PMMA) specimens with unreinforced progressive antibiotic loading, compared to samples reinforced with Kirschner wires, by subjecting these specimens to mechanical compression forces. A difference was observed in the yield of the reinforced specimens with Kirschner wires, in which an antibiotic concentration that exceeded the usual amount was used. In this antibiotic combination of vancomycin powder and liquid gentamicin, the spacer seemed to have a superior structure compared to using only the antibiotic in liquid form. These results are superior to the usually loaded specimens (not exceeding the threshold of 4 g of antibiotic per 40 g of cement), the maximum force recorded being of 20.98 kN and the minimum of 11.54 kN. The reinforced specimens indicated higher values of force, registering differences that varied between 10 kN and approximately 19 kN, thus considering that through the reinforcement with Kirschner wires, the biomechanical qualities of the cement spacers considerably improved.

In vitro elution characteristics of gentamicin-impregnated Polymethylmethacrylate: premixed with a second powder vs. liquid Lyophilization

BackgroundAntibiotic-loaded bone cement, or antibiotic-impregnated polymethylmethacrylate (PMMA), were developed to prevent and treat bone and joint infections. Gentamicin is an antibiotic that is commonly used in combination with PMMA; however, gentamicin powder is hard to obtain in many countries. This study aimed to evaluate the elution characteristics of gentamicin-impregnated PMMA made with lyophilized liquid gentamicin, compared with PMMA; which is made from commercial gentamicin powder.MethodsThe experimental sample was divided into 2 groups: the gentamicin power group (PG-PMMA) and the lyophilized liquid gentamicin group (LG-PMMA). Ten cement spacers were prepared in each group. These were produced by mixing gentamicin powder, or lyophilized liquid gentamicin, with a powder polymer before adding the liquid monomer (2 g of gentamicin and 40 g of PMMA). The volume and surface area of the antibiotic-impregnated cement spacers were 50 cm3 and 110 cm2, respectively. Each spacer was immersed in phosphate-buffered saline, which was changed daily under sterile conditions. The solutions were collected to measure the level of gentamicin using the enzyme multiplied immunoassay technique (EMIT), at days 1, 2, 3, 4, 5, 6, 7, 14, 21, 28, 35 and 42.ResultsThe collections from both groups had high concentrations of gentamicin on day 1 (113.63 ± 23.42 mg/dL in LG-PMMA and 61.7 ±8.37 mg/dL in PG-PMMA), but experienced a continuous decrease over time. The PMMA spacers from both groups could release gentamicin for up to 6 weeks (3.28 ± 1.17 mg/dL in LG-PMMA and 1.21 ± 0.28 mg/dL in PG-PMMA). However, there were significantly higher levels of gentamicin concentrations in the LG-PMMA group compared to the PG-PMMA group at all time points (P< 0.05).ConclusionGentamicin-impregnated PMMA made with lyophilized liquid gentamicin had approximately a two times higher rate of antibiotic elution in preliminary in vitro studies, as compared with PMMA made with premixed gentamicin powder.

Outcomes of major musculoskeletal oncological reconstructions using prolene mesh-a retrospective analysis from a tertiary referral centre

BackgroundAdequate reconstruction of the soft tissue defect following resection of bone tumors is challenging. Prolene mesh, despite being a useful tool, is not widely used due to the fear of deep infection. The aim of this study was to evaluate the functional outcome and complications of using a Prolene mesh in oncological reconstructions. MethodsA retrospective study was conducted in bone tumor patients with soft tissue reconstruction using Prolene mesh between January 2017 and June 2019. Functional evaluation was done using MSTS 93 score. Complications were recorded and were classified as mechanical (dislocation and extension lag) or biological failure (wound problems and deep infection). Comparison was performed between groups with and without biological failure to identify predictive variables. ResultsOf 116 patients, 68 were males and 48 were females, with median age of 22.5 years. Thirty nine patients had tumors of proximal tibia, 23 of proximal femur, 25 of proximal humerus, 24 of pelvis, and five tumors at other sites. Approximately two-thirds (62.9%) of our patients underwent endoprosthetic reconstruction while the rest underwent either biological or cement spacer reconstructions. Excellent or good functional outcomes were reported in 98.3% patients as per MSTS 93 scoring. Complications were noted in 22 patients (18.9%), of which 16 had biological failure, with four patients requiring debridement and mesh removal. Dislocation of prosthesis occurred in 2 patients of proximal femur replacement. Overall re-surgery rate was 5.1% (6 patients). There was no statistically significant difference between the groups with or without biological failure with respect to demographics, site of tumor, type of procedure, blood loss, duration of surgery and history of chemotherapy. ConclusionProlene mesh is a useful tool to reconstruct the soft tissue defects following bone tumor resections. It is readily available, reliable and provides reproducible results, with no added risk of wound complications.

Management of tibial non-unions with Masquelet technique after failed previous treatment options for Grade III open fractures.

Non-union is a serious complication of open tibial fractures. This case series investigates the efficiency of the induced membrane technique in patients with tibial exposed non-union. Eleven consecutive male patients with non-union after an open tibia fracture were enrolled into the study. The mean age of the patients was 40.7 (25-63). Induced membrane technique described by Masquelet was performed. Operative treatment with a temporary polymethylmethacrylate cement spacer to induce membrane formation followed by spacer removal and bone grafting at 7.35 (6-10) weeks were performed. Time to union, time to full weight-bearing, and any complications were evaluated. The average follow-up period of patients was 24.6 (13-40) months after the second stage. The mean length of bone defects after radical debridement was 51 mm (25-98). Fracture healing was observed in 9 patients (81%). The mean time needed to obtain bony union healing was 8.1 (8-12) weeks after second stage of surgery. Patients were allowed to full weight bearing as tolerated at 12 weeks. Two patients were failed to obtain bony union and infection control. One patient had below knee amputation due to persistant infection. Vascularized bone graft was performed for other patient due to the inability to obtain bone union. The induced membrane technique is a reliable and reproducible treatment modality for tibial non-unions after failed open fracture treatment. However, it is unpredictable to obtain bony union and control of infection in initial infected non-unions with a large bone defect.

Blood and synovial fluid calprotectin as biomarkers to diagnose chronic hip and knee periprosthetic joint infections.

Calprotectin (CLP) is produced in neutrophils and monocytes and released into body fluids as a result of inflammation or infection. The aim of this study was to evaluate the utility of blood and synovial CLP in the diagnosis of chronic periprosthetic joint infection (PJI). Blood and synovial fluid samples were collected prospectively from 195 patients undergoing primary or revision hip and knee arthroplasty. Patients were divided into five groups: 1) primary total hip and knee arthroplasty performed due to idiopathic osteoarthritis (OA; n = 60); 2) revision hip and knee arthroplasty performed due to aseptic failure of the implant (AR-TJR; n = 40); 3) patients with a confirmed diagnosis of chronic PJI awaiting surgery (n = 45); 4) patients who have finished the first stage of the PJI treatment with the use of cemented spacer and were qualified for replantation procedure (SR-TJR; n = 25), and 5) patients with rheumatoid arthritis undergoing primary total hip and knee arthroplasty (RA; n = 25). CLP concentrations were measured quantitatively in the blood and synovial fluid using an immunoturbidimetric assay. Additionally, blood and synovial CRP, blood interleukin-6 (IL-6), and ESR were measured, and a leucocyte esterase (LE) strip test was performed. Patients with PJI had higher CLP concentrations than those undergoing aseptic revision in blood (median PJI 2.14 mg/l (interquartile range (IQR) 1.37 to 3.56) vs AR-TJR 0.66 mg/l (IQR 0.3 to 0.83); p < 0.001) and synovial fluid samples (median PJI 20.46 mg/l (IQR 14.3 to 22.36) vs AR-TJR 0.7 mg/l (IQR 0.41 to 0.95); p < 0.001). With a cut-off value of 1.0 mg/l, blood CLP showed a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 87.5%, 89.4%, and 92.1%, respectively. For synovial fluid with a cut-off value of 1.5 mg/l, these were 95.6%, 95%, 95.5%, and 95%, respectively. This small study suggests that synovial and blood CLP are useful markers in chronic PJI diagnosis with similar or higher sensitivity and specificity than routinely used markers such as CRP, ESR, IL-6, and LE. CLP was not useful to differentiate patients with PJI from those with rheumatoid arthritis. Cite this article: Bone Joint J 2021;103-B(1):46-55.

Embedded sensing package for temporary bone cement spacers in infected total knee arthroplasty

The re-infection rate of total knee arthroplasty (TKA) after two stage revision (15%) remains high as it can be challenging to determine whether the infection has been fully cleared between the first and second stage procedures. Temporary embedded sensor systems could be a potential solution to indicate whether the infection has been cleared. In this study a telemetric sensor system to integrate with a bone cement spacer and measure knee joint temperature was designed and evaluated. The sensor package precision, accuracy, hysteresis, and thermal equilibrium were empirically determined. Cadaveric testing was performed with the sensor package implanted inside the femoral notch alongside a pre-formed femoral and tibial bone cement spacer. The limb was tested though 30,000 cycles at 0.5 Hz under a 500 N load. Accuracy and precision of the sensing package were found to be ±0.24 °C and 0.09 °C respectively with negligible hysteresis. Thermal insulation caused by the implant itself was found to produce a thermal time constant of 263 ± 5 s, resulting in a 17 min rise time. Memory capacity enabled data logging every 20 s for a 6 week period before necessitating data transfer. Bluetooth was suitable for data transmission while the package was implanted. Following cyclic loading of the cadaveric specimen, imaging and debridement revealed no issues related to mechanical integrity of the bone cement spacer or encapsulated sensor package. While additional validation is required before use in patients, the concept of temporary embedded sensing technology to aid management of infection treatments is promising.

Use of Antibiotics-Impregnated Cement Spacers for the Management of Postoperative Infection Following Anterior Cervical Discectomy and Fusion: A Case Report

Use of Antibiotics-Impregnated Cement Spacers for the Management of Postoperative Infection Following Anterior Cervical Discectomy and Fusion: A Case Report

Successful Two-Stage Exchange Arthroplasty for Periprosthetic Infection Following Total Knee Arthroplasty: The Impact of Timing on Eradication of Infection.

Background: Periprosthetic joint infection (PJI) represents a serious complication following total knee arthroplasty. In the setting of chronic infections, the two-staged approach has traditionally been the preferred treatment method. The aim of this study was to determine the optimal period of rest between the first and second stage. Furthermore, we analyzed potentially outcome-relevant parameters, such as general and local conditions and the presence of difficult-to-treat or unidentified microorganisms, with regard to their impact on successful treatment of PJI.Patients and Methods: We performed a retrospective analysis of prospectively collected data for all patients treated for PJI at our institution. Seventy-seven patients who had undergone two-stage revision arthroplasty for PJI of the knee were included into the study. Antibiotic-loaded cement spacers were used for all patients.Results: After a median follow-up time of 24.5 months, infection had reoccurred in 14 (18.7%) patients. A prolonged spacer-retention period of more than 83 days was related to a significantly higher proportion of reinfections. Furthermore, significant compromising local conditions of the prosthetic tissue and surrounding skin, as well as repeated spacer-exchanges between first- and second-stage surgery, negatively influenced the outcome. Neither the patients' age nor gender exerted a significant influence on the outcome regarding reinfection rates for patients' age or gender.Conclusions: We observed the best outcome regarding infection control in patients who had undergone second-stage surgery within 12 weeks after first-stage surgery. Nearly 90% of these patients stayed free from infection until the final follow-up. An increased number of performed spacer-exchanges and a bad local extremity grade also had a negative impact on the outcome.

330. Risk Factors for Acute Kidney Injury after the Use of Antibiotic Loaded Bone Cement in Orthopedic Surgery – a Retrospective Case-control Study

BackgroundAs the number of joint replacement surgeries continues to rise, so does the number of joint infections. Many patients end up needing the implantation of antibiotic loaded bone cement (ALBC) to treat their infection. The use of localized high dose vancomycin, tobramycin, and gentamicin may be linked to acute kidney injury (AKI) in certain patients. Our hypothesis is that patients who developed AKI after receiving a joint spacer had a predisposition to AKI due to other comorbidities, high antibiotic doses in ALBC, immunosuppression, or the use of other nephrotoxic drugs pre-op. These patients may need close monitoring of their renal function and serum antibiotic levels after surgery.MethodsWe performed a chart review of 428 patients who underwent an orthopedic surgery that involved insertion of ALBC at our institution between 2015 and 2018. We excluded patients under age 18, those who had antibiotic irrigation only, trauma patients, non-arthroplasty surgeries (such as fractures and debridement of deep wounds), and patients with missing data for 30 days after the surgery. We identified 57 patients who fit our inclusion criteria and received a bone cement spacer or beads to treat an infection of the hip, knee, shoulder, or ankle. We matched patients who had AKI to 2 patients who did not have AKI. Matching was based on age (± 5 years), joint operated on, and antibiotics used.Results15 patients showed an elevated serum creatinine level of over 1.2 within 30 days of surgery. 86.7% of these patients were male, their average age was 64.1 ± 6.2 years old, 40% had hip surgery, 46.7% knee surgery, 6.7% ankle, and 6.7% shoulder. All received vancomycin and tobramycin in Palacos bone cement. Compared to their case-control matches, these patients had more frequent use of immunosuppressive medication, a history of malignancy, a history of previous kidney disease, and obesity. The use of combined intravenous vancomycin and piperacillin-tazobactam post-operatively may also be linked to higher rates of AKI.ConclusionImmunosuppression, obesity, male gender, and history of kidney injury and cancer are factors associated with AKI after ALBC spacer implantation. Further analysis and study are needed to identify potential causation between ALBC use and AKI.Disclosures All Authors: No reported disclosures

Treatment of hindfoot and ankle infections with Ilizarov external fixator or spacer, followed by secondary arthrodesis.

An established treatment strategy in surgical site infection after hindfoot and ankle surgery is a two-stage procedure with debridement and placement of a cement spacer, followed by antibiotic treatment and secondary arthrodesis. However, there is little evidence to favor this treatment over a one-stage procedure with debridement, followed by primary arthrodesis with an Ilizarov external fixator and antibiotic treatment. We compared the infection control andclinical and radiological outcome of a two-stage and a one-stage procedure. In this study, 7 patients with a two-stage revision and 11 patients with a one-stage revision between 2005 and 2015 were included. The primary outcome was infection control (absence of the Musculoskeletal Infection Society PJI criteria) 2 years after the ankle or hindfoot arthrodesis. Secondary outcome measures were the AOFAS hindfoot score and radiological consolidation rate. Infection control was 85% (6 out of 7 patients) in the two-stage group and 81% (9 out of 11 patients) in the one-stage group (p = 1.0). One patient (14%) of the two-stage and two patients (18%) in the one-stage group needed below-knee amputation. In the two-stage group, the mean postoperative AOFAS score was 74.8 (SD:±11.3) versus 71.7 (SD:±17.8) in the one-stage group. Radiological consolidation could be achieved in 71% in the spacer group (n = 5) and in 72% in the Ilizarov external fixator group (n = 9). Infection control, AOFAS score, and radiologic consolidation of hindfoot and ankle arthrodesis were comparable in both groups of patients with complicated postsurgical hindfoot or ankle infections.

Morphological Changes in the Tibial Nerve During the Treatment of Large Tibia Defects Using Ilizarov Apparatus Combining with the Masquelet Technique: Experimental Study

Background. The use of Masquelet technology in combination with non-free osteoplasty according to Ilizarov in order to compensate large defects of the lower leg bones provides proper bone union and recurrence-free course of the disease, but the problem of patient rehabilitation remains relevant. The course and duration of the recovery period depend on the morphofunctional state of the tibial nerves. The purpose of this study was to determine morphological changes in the tibia nerve of dogs during the experimental treatment of large tibial defects using Ilizarov apparatus combining with the Masquelet technique. Materials and Methods. A defect of the upper third of the tibia in the form of false joint was created in 10 mongrel dogs. Then this defect was replaced with 25 mm diastasis, into which a cement spacer was placed. After 30 days, the latter was removed. At the level of the lower third, transverse osteotomy was performed, as well as distraction of 1 mm rate for 4 times per day, until complete contact of the fragments in the defect zone. The tibial nerves were studied within the periods of 60 days of fixation (F60) and 30 days after the fixator removal (FR30). Results. There were no mechanical damages of the nerves. During the experiment a part of epineural veins and arteries had obliterated lumens, two-fold decrease in the numerical density of endoneural arterioles, venules and capillaries was observed in FR30 — 97.5±2.5 in 1 mm2 (normally — 182.0±22.0), that evidenced of microcirculatory disorders progressing towards the end of the experiment. Patterns of Wallerian degeneration were found along with typical damages to fibers during distraction osteosynthesis demyelination and axonal degeneration. In F60 the proportion of modified fibers was 7.7±1.5%, which was 4.8 times higher (р = 0.52×10-5) above normal, the numerical densities and dimensional characteristics of fibers decreased. At the end of the experiment, the proportion of modified conductors 2.3-fold exceeded the norm (p = 0.33×10-4) — 3.7±0.4%, the numerical density of fibers remained 10.2% below the norm (p = 0.0362), making up 17436±865, but the average axon diameter and thickness of myelin sheaths were restored. Conclusion. Microcirculatory dysfunction, axonal atrophy, demyelination, Wallerian degeneration of a part of myelin nerve fibers and a decrease in their number revealed in the tibial nerves during the treatment of large tibia defects using the Masquelet technique combining with Ilizarov non-free bone grafting indicated the need for the use of adequate neurometabolic pharmacotherapy and effective rehabilitation.

Surgical Strategies: Cement Spacer for Staged First Metatarsophalangeal Arthrodesis After Failed Arthroplasty

Revision arthrodesis following surgery for first metatarsophalangeal arthritis (hallux rigidus) is a complex problem. Failed implants, arthroplasty, primary fusion, or infection may result in bone loss with abnormal soft tissue tensions. This requires technically challenging revision surgery necessitating debridement of nonviable bone, culture, and bone grafting of resultant defects. We describe a 2-stage technique for first metatarsophalangeal arthrodesis in the setting of osteolysis, infection, or bone loss. This staged technique allows for the restoration of appropriate soft tissue tension through the use of a temporary cement spacer before structural grafting.

The induced membrane technique for the management of long bone defects.

The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT. A systematic search was performed in CINAHL, The Cochrane Library, Embase, Ovid MEDLINE, and PubMed. We included articles from 1 January 1980 to 30 September 2019. Studies with a minimum sample size of five cases, where the IMT was performed primarily in adult patients (≥ 18 years old), in a long bone were included. Multivariate regression models were performed on patient-level data to determine variables associated with nonunion, postoperative infection, and the need for additional procedures. A total of 48 studies were included, with 1,386 cases treated with the IMT. Patients had a mean age of 40.7 years (4 to 88), and the mean defect size was 5.9 cm (0.5 to 26). In total, 82.3% of cases achieved union after the index second stage procedure. The mean time to union was 6.6 months (1.4 to 58.7) after the second stage. Our multivariate analysis of 450 individual patients showed that the odds of developing a nonunion were significantly increased in those with preoperative infection. Patients with tibial defects, and those with larger defects, were at significantly higher odds of developing a postoperative infection. Our analysis also demonstrated a trend towards the inclusion of antibiotics in the cement spacer having a protective effect against the need for additional procedures. The IMT is an effective management strategy for complex segmental bone defects. Standardized reporting of individual patient data or larger prospective trials is required to determine the optimal implementation of this technique. This is the most comprehensive review of the IMT, and the first to compile individual patient data and use regression models to determine predictors of outcomes. Cite this article: Bone Joint J 2020;102-B(12):1723-1734.

Application of innovative lost circulation cement spacer for production casing in deepwater wells.

Application of innovative lost circulation cement spacer for production casing in deepwater wells.

Комбинированное применение несвободной костной пластики по Илизарову и техники Masquelet при реабилитации пациентов с приобретенными костными дефектами и ложными суставами

Introduction The Masquelet induced membrane technique is effective in the management of acquired heterogeneous long bone defects and pseudarthrosis. The combination of the Masquelet technology and Ilizarov non-free bone grafting seems promising and reduces the risks of recurrence at long-term in patients with congenital pseudarthrosis. Purpose Presentation of new technological solutions that allow combining the advantages of the Ilizarov bone transport and Masquelet bone grafting in patients with acquired bone defects. Materials and methods Retrospective assessment of the results of bone reconstruction in 10 patients who were treated by a combination of Ilizarov and Masquelet bone grafting technologies to repair long bone defects after failures of previous treatment. Fragments of the biomembrane formed around the cement spacer temporarily replacing the tibial gap after resection bone defect or pseudarthrosis were examined in all patients. The studies were carried out using a Reichard sledge microtome, an AxioScope stereomicroscope and an AxioCam ICc 5 digital camera, a JSM- 840 scanning electron microscope and an INCA-200 Energy X-ray electron probe microanalyzer. Results and discussion The combined Masquelet technique and Ilizarov non-free bone plasty provide the conditions that are favorable for reparative processes of the transported fragments. After removal of the spacer, there is a tunnel formed in the interfragmental gap, the walls of which are made of the induced membrane. Bone transport is carried out without technical problems through the compromised tissues which are debrided at the time of distraction initiation, outside the scars. At the same time, there are low risks of inflammation around the transosseous elements; there is no danger of cutting and perforation of soft tissues by transported fragments. Conclusions Complete organotypic rearrangement of the distraction regenerate with the use of Ilizarov non-free bone plasty and the Masquelet technique excludes the possibility of deformities or fractures at the level of newly formed bone areas. Active distraction histogenesis ensures the closure of soft tissue defects without additional reconstructive plastic interventions. The revealed dependence of the induced membrane blood supply on the method of treatment previously used might be a criterion for predicting the treatment outcome in patients with acquired bone defects and pseudarthrosis.