Effect of Protein-Glutaminase on Calcium Sulphate-Induced Gels of SPI with Different Thermal Treatments.

The effects of protein-glutaminase (PG) on calcium sulphate (CaSO4)-induced gels of soy protein isolate (SPI) with different heat treatment levels were investigated. The time-dependent degree of deamidation showed that the mild denaturation of the protein favored the deamidation. The particle size distribution showed that the heat treatment increased the SPI particle size, and the particle size distribution of the SPI shifted to the right or increased the proportion of the large particle size component as the degree of deamidation increased for each sample. Rheological analysis showed that the deamidation substantially pushed up the gel temperature and decreased the value of G'. The gel strength and water-holding capacity showed that the higher the amount of enzyme added, the more significant the decrease in gel strength, while the gel water-holding capacity increased. In summary, the deamidation of PG and heat treatment can affect the gel properties of SPI synergistically.

Intramedullary application of local antibiotic bullets for the treatment of long bone fracture related infection.

PURPOSE: The optimal means of local antibiotic delivery for fracture related infection is unknown. Until now, intramedullary application of calcium sulphate based local antibiotics has been challenging. We report on the use of a newly available mode of preparation and delivery: the Stimulan Bullet Mat and Introducer (Biocomposites Ltd, Staffordshire, England). METHODS: A retrospective analysis of prospectively collected data for infection cases at two separate tertiary referral institutions was performed. We included cases of long bone FRI with a retained intramedullary nail, treated with a single stage protocol of metalwork removal, debridement, local antibiotic application using the novel mould and applicator, with additional bony stabilisation and soft tissue reconstruction where required. RESULTS: All 13 patients achieved infection remission rate with an average follow-up of 19.7 months (range 12-28). All 6 patients with infection around an unhealed fracture achieved union at an average 8 months (range 4-12) from debridement. No patients developed aseptic wound leak. CONCLUSIONS: Antibiotic impregnated calcium sulphate can be used safely as part of a single stage treatment protocol for the treatment of long bone fracture related infection following intramedullary nailing. We have demonstrated high rates of infection remission and union, using a newly available intramedullary applicator.

Evaluation of correlated studies using liquid cell and cryo-transmission electron microscopy: Hydration of calcium sulphate and the phase transformation pathways of bassanite to gypsum.

Insight into the nucleation, growth and phase transformations of calcium sulphate could improve the performance of construction materials, reduce scaling in industrial processes and aid understanding of its formation in the natural environment. Recent studies have suggested that the calcium sulphate pseudo polymorph, gypsum (CaSO4 ·2H2 O) can form in aqueous solution via a bassanite (CaSO4 ·0.5H2 O) intermediate. Some in situ experimental work has also suggested that the transformation of bassanite to gypsum can occur through an oriented assembly mechanism. In this work, we have exploited liquid cell transmission electron microscopy (LCTEM) to study the transformation of bassanite to gypsum in an undersaturated aqueous solution of calcium sulphate. This was benchmarked against cryogenic TEM (cryo-TEM) studies to validate internally the data obtained from the two microscopy techniques. When coupled with Raman spectroscopy, the real-time data generated by LCTEM, and structural data obtained from cryo-TEM show that bassanite can transform to gypsum via more than one pathway, the predominant one being dissolution/reprecipitation. Comparisons between LCTEM and cryo-TEM also show that the transformation is slower within the confined region of the liquid cell as compared to a bulk solution. This work highlights the important role of a correlated microscopy approach for the study of dynamic processes such as crystallisation from solution if we are to extract true mechanistic understanding.

A Histologic and Histomorphometric Evaluation of an Allograft, Xenograft, and Alloplast Graft for Alveolar Ridge Preservation in Humans: A Randomized Controlled Clinical Trial.

The aim of this study was to clinically evaluate the guided bone regeneration (GBR) potential of allograft, xenograft, and alloplastic materials in combination with resorbable membranes in extraction sockets. The qualitative and quantitative assessments of this prospective study were accomplished through histologic and histomorphometric analysis. Three experimental groups and 1 control group for comparison (n = 8) received either an allograft (human cancellous bone, freeze dried, Deutsches Institut für Zell und Gewebeersatz, Berlin, Germany), xenograft (BioOss, Geistlich Pharma AG, Wolhusen, Switzerland), or alloplast (biphasic calcium sulphate, Bondbone, MIS Implants Technologies Ltd., Charlotte, NC). The negative control group received no regenerative material. Tissue samples were then qualitatively and quantitatively evaluated as a function of percentage of new vital bone, graft particles content, soft tissue, and bone marrow over time. All 3 study groups presented bone volume suitable for the successful placement of a dental implant. The xenograft group yielded significantly less amount of vital bone compared with the allograft and alloplast groups. When comparing the percentage of residual graft particles, there was significantly greater amounts associated with the xenograft group in contrast to the allograft and alloplast groups. Similarly, a significantly increased amount of soft tissue percentage was observed within the xenograft group relative to all other groups. No significant differences were observed in the percentage of residual graft particles between the allograft and alloplast groups. There were also no significant differences detected in vital bone percentage between the allograft, alloplast, and control groups. When evaluating the bone marrow percentage, the only significant difference detected was between the xenograft and alloplast materials. Overall, no complications (ie, fever, malaise, purulence or fistula) were observed during the entirety of clinical trial among all patients. The greatest GBR potential was associated with the allograft material because of the greater degree of vital bone and the lowest percentage of residual graft particles. All studied bone substitute materials resulted in bone apposition for efficient use in alveolar ridge preservation procedures.

Asprin-loaded strontium-containing α-calcium sulphate hemihydrate/nano-hydroxyapatite composite promotes regeneration of critical bone defects.

Our laboratory originally synthesized strontium(Sr)-containing α-calcium sulphate hemihydrate/nano-hydroxyapatite composite (Sr-α-CSH/n-HA) and demonstrated its ability to repair critical bone defects. This study attempted to incorporate aspirin into it to produce a better bone graft material for critical bone defects. After 5% Sr-α-CSH was prepared by coprecipitation and hydrothermal methods, it was mixed with aspirin solution of different concentrations (50 µg/ml, 200 µg/ml, 800 µg/ml and 3200 µg/ml) at a fixed liquid-solid ratio (0.54 v/w) to obtain aspirin-loaded Sr-α-CSH/n-HA composite. In vitro experiments were performed on the composite extracts. The tibial defects (3 mm*5 mm) in SD rat model were filled with the composite for 4 weeks and 12 weeks to evaluate its osteogenic capacity in vivo. Our results showed its capability of proliferation, migration and osteogenesis of BMSCs in vitro got improved. In vivo treatment with 800 µg/ml aspirin-loaded Sr-α-CSH/n-HA composite led to significantly more new bone formation in the defects compared with Sr-α-CSH/n-HA composite and significantly promoted the expression of osteogenic-related genes and inhibited osteoclast activity. In general, our research suggests that aspirin-loaded Sr-α-CSH/n-HA composite may have a greater capacity of repairing tibial defects in SD rats than simple Sr-α-CSH/n-HA composite.

Calcium sulphate for control of bleeding after oral surgery in anticoagulant therapy patients.

Control of bleeding after oral surgery is mandatory in patients taking anticoagulants. There are different haemostatic measures to prevent post-surgical bleeding. The aim of the present paper is to study the use of a haemostatic agent, calcium sulphate (CaS) (P30, Ghimas, Bologna, Italy) for controlling post-surgical bleeding in a group of patients treated with warfarin therapy for thromboembolic states. Twenty teeth (12 mandibular molars, 8 maxillary molars) in 20 patients (14 male and 6 females) with a mean age of 54.3 years (±10.3 years) were included in the study. The patients were divided into 2 groups; in the study group of 10 patients calcium sulphate was used in layers to fill the socket after extraction, while for the 10 patients in the control group put a gauze with tranexamic acid was put in the extraction site immediately after extraction, and half an hour after extraction. The outcome was bleeding in subsequent days. Bleeding at post-operative day 1 was significant in 5 patients of the control group, however, in the study group treated with calcium sulfate there was no bleeding in any patient (p value 0.0055). CaS demonstrated to be a good haemostatic agent for controlling bleeding after oral surgery in patients taking anticoagulants.

Extensive eggshell-like debridement technique plus antibiotic-loaded calcium sulphate for one-stage treatment of chronic calcaneal osteomyelitis.

BACKGROUND: Management of chronic calcaneal osteomyelitis is challenging. At present, there is still no widely accepted, simple, and effective surgical method to eradicate the infection and prevent osteomyelitis recurrence. The objective of this study was to assess the outcomes of one-stage treatment of chronic calcaneal osteomyelitis with a shape-preserving debridement technique combined with antibiotic-loaded calcium sulphate. METHODS: Between 2012 and 2018, 33 patients (33 limbs) with chronic calcaneal osteomyelitis were treated with a novel debridement technique, named "eggshell-like debridement", plus antibiotic-impregnated calcium sulphate. The infection remission rate, recurrence rate, and amputation rate were analyzed. The American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score was used to assess postoperative hindfoot function. RESULTS: 26 patients (81.8%) achieved infection remission without recurrence. In the patients with osteomyelitis remission, pain, limitation of movement, sinus tracts, and typical redness and swelling were generally eliminated. Most of the patients could tolerate full weight-bearing without pain. The average AOFAS ankle and hindfoot score was 88 points (range, 67-100 points), implying the foot function was mostly restored. 6 patients (18.2%) had osteomyelitis recurrence but no amputation was required to elimilate the infection. CONCLUSIONS: Eggshell-like debridement combined with antibiotic-loaded calcium sulphate is an effective method for one-stage management of chronic calcaneal osteomyelitis. With the application of this technique, secondary autogenous bone or muscle flap grafts are unnecessary. The surgical procedure can be simplified whlie the hindfoot function is well preserved.

Bleeding control with calcium sulphate after oral surgery in anticoagulant therapy patients.

Control of bleeding after oral surgery, is mandatory in patients taking anticoagulants. There are different haemostatic measure to prevent post-surgical bleeding. The aim of our study is to use a homeostatic agent, Calcium sulphate (P30, Ghimas, Bologna, Italy) for controlling post-surgical bleeding in a group of patients treated with warfarin therapy for thromboembolic states. Twenty teeth (12 mandibular molars, 8 maxillary molars) in 20 patients (14 men and 6 woman) with a mean age of 54.3 years (± 10.3 years) were included in the study. The patients were divided in 2 group; in 10 patients of the study group was used Calcium sulphate (P30, Ghimas, Bologna, Italy) in layers to fill the socket after extraction, while in control group was recommended to put a gauze with tranexamic acid in the extraction site immediately after extraction, and half an hour after extraction. The outcome was bleeding in subsequent days. Bleeding at post operative day 1 was significant in 5 patients of control group, otherwise in study group treated with calcium sulfate there was no bleeding in any patient (p. value 0.0055). CaS demonstrated to be a good hemostatic agent for controlling bleeding after oral surgery in patients taking anticoagulants.

One-stage surgery for adult chronic osteomyelitis: concomitant use of antibiotic-loaded calcium sulphate and bone marrow aspirate.

PURPOSE: To report our experience with one-stage treatment of chronic osteomyelitis using a prospective protocol involving the concomitant use of the antibiotic-loaded calcium sulphate pellets with addition of bone marrow aspirate after bony debridement. PATIENTS AND METHODS: A total of 30 patients with the mean age of 26.2 years were treated according to a protocol that included (1) surgical debridement of bone and infected tissues, (2) local antibiotic therapy including vancomycin and garamycin loaded on calcium sulphate space filling biodegradable pellets, (3) bone marrow aspirate added to the biocomposite, (4) primary closure with external fixation (when needed) and (5) intravenous antibiotics according to culture and sensitivity results. RESULTS: After a minimum of one year follow-up, infection was eradicated in 23 (76.7%) patients, the average rate of filling of the bony defect was 70.47%, complete filling of defect in 15 patients (50%) and pathological fracture in one patient. CONCLUSION: The technique proved safety and efficacy in eradicating the infection and bony healing of the defects after debridement. Simple bone marrow aspiration is cheap, reproducible, safe and not exhausting the scanty autograft resources.

Comparative maxillary bone-defect healing by calcium-sulphate or deproteinized bovine bone particles and extra cellular matrix membranes in a guided bone regeneration setting: an experimental study in rabbits.

OBJECTIVES: The aim of this study was to histologically compare the dynamics of bone healing response between calcium sulphate (CaS) and deproteinized bovine bone mineral (DBBM) particles in guided bone regeneration utilizing an extracellular matrix membrane (ECM) as barrier. MATERIALS AND METHODS: Eighteen rabbits were used in thisstudy. 5 × 5 mm defects were created in the edentulous space between the incisors and molars in the maxilla. The CaS and DBBM particles were placed in the defects, with or without the placement of a membrane by means of random selection. Healing was evaluated at 2, 4 and 8 weeks by histology. RESULTS: A total resorption of the CaS material was seen already at 2 weeks. Only minor resorption could be seen of the DBBM particles. The CaS group showed significantly more bone regeneration at all three healing periods compared to the DBBM group. The addition of an ECM membrane demonstrated significant additional effect on bone regeneration. The CaS group showed significant increased amounts of blood vessels compared to the DBBM group. CONCLUSIONS: Thisstudy showed that CaS in combination with an ECM membrane provided synergistic effects on bone regeneration, seemingly due to stimulating angiogenesis in the early healing process.

Water recovery from saline streams produced by electrodialysis.

Advances in technologies to enable water reuse in industry have been the objective of many research efforts, mainly due to the need to reduce the use of natural resources and due to factors related to their availability. This paper evaluates the crystallization of salts from petrochemical saline waste to achieve zero water discharge by the recovery of water and dissolved salts as a solid mixture. In line with process symbiosis, the recovered water should be suitable for use as cooling water in heat exchangers. Vacuum evaporative crystallization, at the batch scale, was used to remove the salts present in the concentrated stream from reverse electrodialysis of pretreated wastewater by a biological process. The partition of organic compounds in the feed solution between the condensate and the mother liquor was obtained from measurements of the total organic carbon and total nitrogen in the solutions. The solid phases formed experimentally are compared with those predicted by chemical modelling by PHREEQC. The recovered water presented almost 50 times less total dissolved solids than the feed stream (from 2100 to 44 mg/L). Calcium sulphate hydrate, calcium sulphate and sodium chloride were the majority crystalline phases formed, in accordance with the modelling by PHREEQC.

Development of anti-scale poly(aspartic acid-citric acid) dual polymer systems for water treatment.

The formation of calcium sulphate and calcium carbonate scale poses major problems in heat exchangers and water cooling systems, thereby affecting the performance of these types of equipment. In order to inhibit these scale formations, new types of biodegradable water soluble single polymer and dual poly(aspartic acid-citric acid) polymers were developed and tested. The effectiveness of single polymer and four different compositions of poly aspartic acid and citric acid dual polymer systems as scale inhibitors were evaluated. Details of the synthesis, thermal stability, scale inhibition and the morphological characterization of single and dual polymers are presented in this scientific paper. It was found that the calcium sulphate scale inhibition rate was in the range 76.06-91.45%, while the calcium carbonate scale inhibition rate observed was in the range 23.37-30.0% at 65-70 °C. The finding suggests that the water soluble dual polymers are very effective in sulphate scale inhibition in comparison of calcium carbonate scale inhibition.

Debridement, Antibiotic Pearls, and Retention of the Implant (DAPRI) in the Treatment of Early Periprosthetic Knee Joint Infections: A Literature Review.

(1) Background: Periprosthetic joint infections (PJIs) are severe and frightening complications in orthopaedic surgery, and they are generally divided into three categories: early infections (those occurring within the first 4-6 weeks), delayed infections (those occurring between 3 and 24 months), and late infections (those occurring more than 2 years after surgery). PJI treatment comprises "debridement, antibiotics, and implant retention" (DAIR), single-stage revision, and double-stage revision. Nowadays, to improve the chances of retaining an infected implant and to improve the traditional DAIR method, a modified surgical technique has been developed, named DAPRI (debridement, antibiotic pearls, and retention of the implant). Our study aims to present an up-to-date concept evaluation of the DAPRI technique and its success rate. (2) Methods: Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards were followed, applying a protocol defined by the authors: a total of 765 articles were identified, and at the end of the screening process only 7 studies were included. (3) Results: Currently, the DAPRI procedure can be performed only on patients who have had PJI symptoms for less than 4 weeks, and in order to achieve the highest success rate, indications are quite strict: it is appropriate in patients with acute, superficial infections without sinus tract presence, and well-fixed implants with known sensitive bacteria. The DAPRI surgical method follows a step-by-step process consisting of a first phase of biofilm identification with intra-articular injection of methylene blue, followed by biofilm removal (thermic, mechanical, and chemical aggression), and a last step consisting of prevention of PJI recurrence by using calcium sulphate antibiotic-added beads. (4) Conclusions: The DAPRI approach improves the traditional DAIR technique. It is a correct treatment for acute and early haematogenous PJI, and improves the DAIR success rate.

Definitive single-stage surgery for treating diabetic foot osteomyelitis: a protocolized pathway including antibiotic bone graft substitute use.

BACKGROUND: Diabetic foot ulcers (DFUs) are a challenging complication of diabetes mellitus, often leading to poor clinical outcomes and significant socioeconomic burdens. We evaluated the effectiveness of a definitive single-stage protocolized surgical management pathway, including the use of local antibiotic bone graft substitute, for the treatment of infected DFUs with associated osteomyelitis. METHODS: A retrospective cohort study was conducted. Medical records were extracted (from January 2017 to December 2020) to establish a database consisting of patients who underwent surgical intervention for the treatment of an infected DFU with osteomyelitis. Patients were divided into conventional (control) and protocolized (intervention) surgical groups depending on the treatment received. Clinical outcomes were assessed over a 12-month follow-up period. RESULTS: A total of 136 consecutive patients were included (conventional = 33, protocolized = 103). The protocolized group demonstrated a statistically significant reduction in the mean number of operations performed per patient (1.2 vs. 3.5) (P < 0.001) and a shorter accumulative hospital length of stay (12.6 vs. 25.1 days) (P < 0.001) compared to the conventional group. Major amputation rates were significantly lower in the protocolized group (2% vs. 18%) (P < 0.001). Within 12 months of surgical intervention, the protocolized group exhibited an ulcer healing rate of 89%, with a low rate of recurrence (3%). CONCLUSION: The protocolized surgical pathway, including local antibiotic bone graft substitute use, demonstrated superior outcomes compared to conventional management for the treatment of infected DFUs with osteomyelitis. Further research is needed to evaluate the cost-effectiveness and generalizability of this approach.

The Safety of Glycopeptide-Impregnated Calcium Sulphate Following Debridement, Antibiotics and Implant Retention (DAIR) for Infected Total Knee Replacement.

Background and objective The impact of prosthetic joint infection (PJI) stretches far beyond the physical nature of the disease. It can result in psychological and social consequences, with significant morbidity and mortality for patients. Calcium sulphate-based delivery agents are effective in the management of PJI, yet with associated risks of systemic adverse events. This study aims to evaluate the risk of systemic adverse events when using calcium-sulphate-based local antibiotic delivery agents in the management of PJIs. Methodology We identified 43 patients who underwent debridement, antibiotics and implant retention (DAIR) for infected total knee arthroplasty (TKA) between 2008 and 2014. Patients in the control groupunderwent conventional intravenous and then oral antibiotic administration, while those in the intervention groupunderwent additional local antibiotic therapy via a calcium sulphate alpha hemihydrate matrix. Case notes and laboratory results data were compiled to establish the safety and efficacy of local glycopeptide delivery. Results Serum vancomycin levels were within the safe therapeutic range for all patients in the intervention group with no difference in serum assays between treatment groups (intervention 7.7 mg/L; control 8.0 mg/L; P = 0.85). Renal function for the study cohort improved at every time point post-operatively when referenced against pre-operative renal function (P < 0.05). There was no difference in renal function between intervention and control groups on day 1, one week, six weeks or 12 weeks post-operatively (P = 0.78, 0.89, 0.20 and 0.50). Conclusions Local glycopeptide delivery via a calcium sulphate alpha hemihydrate matrix did not result in systemic adverse consequences specifically not raising the systemic level of glycopeptide, nor reducing renal function. Implications for future research Although demonstrates a safety profile and potential therapeutic benefit, the long-term efficacy of this approach needs to be established. Importantly, selection bias may contribute to masking clinically significant differences in post-operative outcomes.

Can we build better compost? Use of waste drywall to enhance plant growth on reclamation sites.

Compost is a readily available source of organic matter and nutrients and is produced large scale in many jurisdictions. Novel advancements in composting include addition of construction waste, such as drywall, to address its disposal while potentially improving compost quality for use in land reclamation. Varying compositions (15-30% by weight) of coarse and ground waste drywall were added to manure and biosolids during composting. Six composts were applied at four rates (0, 50, 100, 200 Mg ha(-1)) to three reclamation soils (agricultural, urban clean fill, oil sands tailings). Response to composts was assessed in the greenhouse with three plant species (Hordeum vulgare L. (barley), Agropyron trachycaulum (Link) Malte (slender wheat grass) and Festuca saximontana Rydb. (rocky mountain fescue). Drywall added to biosolids or manure during composting had no detrimental effects on vegetation; any negative effects of compost occurred with and without drywall. In agricultural soil and clean fill, biosolids composts with 15% coarse and 18% ground drywall improved native grass response, particularly biomass, relative to biosolids compost without drywall. Drywall manure composts reduced native grass response relative to manure compost without drywall. Only low quality tailings sand was improved by 30% coarse drywall. Compost rate significantly affected above and below ground biomass in agricultural soil and reduced performance of native species at highest rates, suggesting a threshold beyond which conditions will not be suitable for reclamation. Grinding drywall did not significantly improve plant performance and use of coarse drywall would eliminate the need for specialized equipment and resources. This initial research demonstrates that drywall composts are appropriate soil amendments for establishment of native and non native plant species on reclamation sites with consideration of substrate properties and plant species tolerances to dictate which additional feed stocks should be used.

Effectiveness of an Antibiotic-impregnated Bioabsorbable Carrier for the Treatment of Chronic Intramedullary and Diffuse Osteomyelitis.

Aim: The surgical management of chronic intramedullary osteomyelitis involves debridement of affected non-viable tissue and the use of antibiotics. Where surgery leaves a cavity, dead-space management is often through antibiotic-impregnated bone cement. These depots of local antibiotics are variable in elution properties and need removal. We review our unit's experience using a bioabsorbable synthetic calcium sulphate to deliver gentamicin as an adjunct in the treatment of osteomyelitis involving the medullary canal. Materials and methods: We retrospectively reviewed 34 patients with chronic osteomyelitis who were treated using this method in our institute. Variables recorded included aetiology, previous interventions, diagnostic criteria, radiological features, serology, and microbiology. The Cierny-Mader system was used to classify. Follow-up involved a survival analysis to time to recurrence, clinical and functional assessment (AOFAS-Ankle/IOWA knee/Oxford Hip/DASH scores) and a general health outcome questionnaire (SF36). The primary outcome measure was clinical recurrence of infection. Results: There were 24 male and 10 female patients. The mean age at presentation was 47 years (20-67). Clinical, laboratory, radiological, and patient reported outcomes were obtained at a median follow-up of 2.5 years (1.4-6.6 years). The bones involved were the femur (14, 41%), tibia (16, 47%), radius (1, 3%), and humerus (3, 9%). There were 13 cases classified as Cierny-Mader stage IV (diffuse with intramedullary osteomyelitis) and 21 cases as Cierny-Mader stage I. The median Oxford Hip score was 38 (11 patients, range 9-48). The median AOFAS score was 78 (14 patients, range 23-100). The median IOWA knee score was 71 (25 patients, range 22-95). The median DASH score was 33 (2 patients, range 1.7-64.2). There were two recurrences. The treatment success to date is 94%. Conclusion: In our series of patients, bioabsorbable carriers of antibiotics appear to be effective adjuncts to surgical treatment of osteomyelitis and were associated with high clinical success rates. How to cite this article: Selvaratnam V, Roche A, Narayan B, et al. Effectiveness of an Antibiotic-impregnated Bioabsorbable Carrier for the Treatment of Chronic Intramedullary and Diffuse Osteomyelitis. Strategies Trauma Limb Reconstr 2023;18(3):148-154.

Joint fluid concentrations of amphotericin B after local application with calcium sulphate-report of 2 cases.

Fungal periprosthetic joint infections (PJI) are difficult to treat, due to important biofilm formation and limited local penetration of systemically administered antifungals. Calcium sulphate (CaSO4 ) might be a promising carrier to increase local concentration of antifungals. We hypothesized that local amphotericin B release from CaSO4 is high enough to significantly contribute to treatment of fungal PJI. We report joint fluid and serum concentrations of amphotericin B after local application with CaSO4 as an implanted resorbable carrier material as adjunct to standard surgical and systemic antifungal treatment in two cases of PJI with Candida spp. Maximal joint fluid amphotericin B concentration was 14.01 mg/L 5 days after the second local administration of liposomal amphotericin in Case One and 25.77 mg/L 14 days after the second local administration in Case Two. Concentrations higher than minimal inhibitory concentrations (MIC) could be measured for 21 days and 17 days after local administration in Case One and Two, respectively. In Case Two, serum concentration of amphotericin B was <0.01 mg/L 3 days after local administration of 450 mg liposomal amphotericin B. No local or systemic adverse reaction was observed. Fungal PJI was successfully eradicated in both cases with a follow-up of 12 months in Case One and 20 months in Case Two. Application of amphotericin B-loaded CaSO4 was associated with joint fluid concentrations higher than minimal inhibitory concentrations for Candida spp. for approximately 3 weeks, with the advantage that the carrier material dissolves spontaneously and does not require secondary removal. Relapse of fungal infections did not occur in these two patients.

Is the routine use of local antibiotics in the management of periprosthetic joint infections justified?

Periprosthetic joint infection (PJI) following total hip and total knee arthroplasty continues to be a leading cause of re-operation and revision arthroplasty. Not only is the treatment of PJI notoriously challenging, but success rates are variable. Regardless of the surgical strategy used, successful management of PJI requires a comprehensive surgical debridement focused at eradicating the underlying biofilm followed by appropriate antimicrobial therapy. Although systemic antimicrobial delivery continues to be a cornerstone in the treatment of PJI, many surgeons have started using local antibiotics to deliver higher concentrations of antibiotics directly into the vulnerable joint and adjacent soft tissues, which often have compromised vascularity. Available evidence on the use of topical powder, bone cement, and calcium sulphate carriers for local delivery of antibiotics during the initial treatment of PJI is limited to studies that are extremely heterogeneous. There is currently no level-1 evidence to support routinely using these products. Further, appropriately powered, prospective studies are needed to quantify the safety and efficacy of antibiotic-located calcium-sulphate carriers to justify their added costs. These products should not encourage surgeons to deviate from best practice guidelines, such as those recommended during the International Consensus Meeting on Musculoskeletal Infections.

Treatment of tibial large bone defects: A comparative study of bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate versus bone transport alone with antibiotic-impregnated calcium sulphate.

PURPOSE: To compare the bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate versus bone transport alone with antibiotic-impregnated calcium sulphate for the treatment of tibial large bone defects. METHODS: A retrospective analysis was conducted by enroling 33 surgically treated patients with tibial large bone defects after the debridement for tibial infection or osteomyelitis who were admitted in Lower Limb Surgery Ward of Traumatic orthopaedic Department, Xi'an Honghui Hospital from January 2018 to January 2021. All the patients were categorized in Group A (transport over intramedullary nail, 12 cases) and Group B (transport alone, 21 cases) based on the surgery strategy. The collected clinical materials and data included gender, age, injury mechanism, smoking habits, comorbidity diseases, initial fracture type (open or close), bone defect size, surgical duration, intraoperative bleeding loss, resorption time of calcium sulphate, bone transport time, external fixation time, external fixation index, weight bearing time, complications and Paley bone and functional criteria. RESULTS: Thirty-three patients were enroled and successfully followed up with an average time of 15.25±4.31 months ranged from 8 to 21 months in Group A and an average time of 17.09±5.64 months ranged from 9 to 31 months in Group B. No significantly statistical differences of the demographic data were discovered between the two groups. There were no significantly statistical differences of the average bone defect size, intraoperative bleeding loss, resorption time of calcium sulphate and bone transport time between the two groups. However, the average surgical duration (P = 0.002) was significantly longer in Group A than Group B and the average external fixation time (P<0.001), external fixation index(P = 0.002) and weight bearing time (P = 0.030) were significantly shorter in Group A than Group B. No significantly statistical difference of excellent and good rate of bone outcomes and complication rate was observed, however, the excellent and good rate of functional outcomes (P = 0.041) was significantly higher in Group A than Group B. CONCLUSION: Compared with the conventional Ilizarov technique combining with antibiotic-impregnated calcium sulphate for large tibial bone defects, bone transport over an intramedullary nail in combination with antibiotic-impregnated calcium sulphate had favourable external fixation time, external fixation index, weight bearing time and clinical functional outcomes which effectively suppressed the infection and allowed patients earlier removal of the external fixator and weight bearing for rehabilitation.