Hypercalcaemia following the use of antibiotic-eluting absorbable calcium sulphate beads in revision arthroplasty for infection

Limitations and modifications in the clinical application of calcium sulfate

Calcium sulfate and calcium sulfate-based biomaterials have been widely used in non-load-bearing bone defects for hundreds of years due to their superior biocompatibility, biodegradability, and non-toxicity. However, lower compressive strength and rapid degradation rate are the main limitations in clinical applications. Excessive absorption causes a sharp increase in sulfate ion and calcium ion concentrations around the bone defect site, resulting in delayed wound healing and hypercalcemia. In addition, the space between calcium sulfate and the host bone, resulting from excessively rapid absorption, has adverse effects on bone healing or fusion techniques. This issue has been recognized and addressed. The lack of sufficient mechanical strength makes it challenging to use calcium sulfate and calcium sulfate-based biomaterials in load-bearing areas. To overcome these defects, the introduction of various inorganic additives, such as calcium carbonate, calcium phosphate, and calcium silicate, into calcium sulfate is an effective measure. Inorganic materials with different physical and chemical properties can greatly improve the properties of calcium sulfate composites. For example, the hydrolysis products of calcium carbonate are alkaline substances that can buffer the acidic environment caused by the degradation of calcium sulfate; calcium phosphate has poor degradation, which can effectively avoid the excessive absorption of calcium sulfate; and calcium silicate can promote the compressive strength and stimulate new bone formation. The purpose of this review is to review the poor properties of calcium sulfate and its complications in clinical application and to explore the effect of various inorganic additives on the physicochemical properties and biological properties of calcium sulfate.

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.

Hypercalcemia Secondary to Antibiotic-Eluting Calcium Sulfate Beads

The use of calcium sulfate beads (CSBs) as a carrier for local delivery of antibiotics is increasingly reported for the treatment of localized infections. They are used most commonly in bone and joint infections, post-trauma infections, diabetes-related foot wounds, and vascular grafts. Hypercalcemia is rarely reported with CSB use but is an important safety concern, and patients at higher risk should be identified prospectively and followed carefully postoperatively. This case report details an 85-year-old male who developed severe, symptomatic postoperative hypercalcemia after antibiotic bead placement in the right knee. He presented with confusion, weakness, and lethargy, and was subsequently treated with fluids, calcitonin, and alendronate. The patient quickly returned to normal mental status, and calcium levels normalized, leading to discharge. The case report and review of the literature describe an incident of severe hypercalcemia attributed to the use of antibiotic-eluting CSBs and describe the risk factors and time course that may be expected.

Efficacy and Safety of Antibiotic Impregnated Microporous Nanohydroxyapatite Beads for Chronic Osteomyelitis Treatment: A Multicenter, Open-Label, Prospective Cohort Study

Chronic osteomyelitis is still a serious health problem that causes disabling conditions and has an impact on the quality of life. The objective of this study was to determine the clinical efficacy and safety of localized antibiotics delivery via impregnated microporous nanohydroxyapatite (nHA-ATB) beads for chronic osteomyelitis treatment. A total of 62 patients were enrolled in this study. After radical surgical debridement, the bone defect was filled with three types of antibiotics (vancomycin or gentamicin or fosfomycin) impregnated HA beads. The follow-up period was 48 weeks. It was found that the success rate was approximately 98% with a re-infection in only one patient. Quality of life of all patients after treatment improved significantly over time. Systemic exposure to vancomycin and gentamicin after beads implantation was limited and high local antibiotics concentrations were found in wound drainage fluid at 24, 48 and 72 h. Blood biochemistry measurements did not show any nephrotoxic or hepatotoxic effects. 20 adverse events were reported, but 90% of the events were resolved without having to remove the beads and the patients recovered. Satisfactory outcomes were observed in terms of success rate, quality of life and adverse effect. nHA-ATB beads impregnated by vancomycin or gentamicin or fosfomycin could potentially be employed as an alternative product of choice for localized antibiotics delivery in chronic osteomyelitis treatment.

Single-stage revision for chronic periprosthetic joint infection after knee and hip arthroplasties: indications and treatments

Single-stage revision for chronic periprosthetic joint infection has been introduced 40 years ago. This option is gaining more and more attention as well as popularity. It is a reliable treatment for the chronic periprosthetic joint infection after knee and hip arthroplasties when implemented by an experienced multi-disciplinary team. However, its indications and corresponding treatments remain controversial. This review focused on the indications and specific treatments related to the option, with an attempt to help surgeons to use this method with more favorable outcomes.

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.

Hypercalcemia: A Review

IMPORTANCE

Hypercalcemia affects approximately 1% of the worldwide population. Mild hypercalcemia, defined as total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L), is usually asymptomatic but may be associated with constitutional symptoms such as fatigue and constipation in approximately 20% of people. Hypercalcemia that is severe, defined as total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) or that develops rapidly over days to weeks, can cause nausea, vomiting, dehydration, confusion, somnolence, and coma.

OBSERVATIONS

Approximately 90% of people with hypercalcemia have primary hyperparathyroidism (PHPT) or malignancy. Additional causes of hypercalcemia include granulomatous disease such as sarcoidosis, endocrinopathies such as thyroid disease, immobilization, genetic disorders, and medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A. Hypercalcemia has been associated with sodium-glucose cotransporter 2 protein inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2, ketogenic diets, and extreme exercise, but these account for less than 1% of causes. Serum intact parathyroid hormone (PTH), the most important initial test to evaluate hypercalcemia, distinguishes PTH-dependent from PTH-independent causes. In a patient with hypercalcemia, an elevated or normal PTH concentration is consistent with PHPT, while a suppressed PTH level (<20 pg/mL depending on assay) indicates another cause. Mild hypercalcemia usually does not need acute intervention. If due to PHPT, parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement. In patients older than 50 years with serum calcium levels less than 1 mg above the upper normal limit and no evidence of skeletal or kidney disease, observation may be appropriate. Initial therapy of symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates, such as zoledronic acid or pamidronate. In patients with kidney failure, denosumab and dialysis may be indicated. Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas). Treatment reduces serum calcium and improves symptoms, at least transiently. The underlying cause of hypercalcemia should be identified and treated. The prognosis for asymptomatic PHPT is excellent with either medical or surgical management. Hypercalcemia of malignancy is associated with poor survival.

CONCLUSIONS AND RELEVANCE

Mild hypercalcemia is typically asymptomatic, while severe hypercalcemia is associated with nausea, vomiting, dehydration, confusion, somnolence, and coma. Asymptomatic hypercalcemia due to primary hyperparathyroidism is managed with parathyroidectomy or observation with monitoring, while severe hypercalcemia is typically treated with hydration and intravenous bisphosphonates.

Hypercalcaemia caused by calcium sulfate beads

Hypercalcaemia is a relatively common metabolic disturbance seen in hospitalised patients; however, given the complicated systems of calcium regulation, it can take a significant amount of time and testing to pinpoint the aetiology. This case discusses a patient who developed acute hypercalcaemia from calcium sulfate-containing antibiotic beads placed during an orthopaedic procedure. These beads are used in surgical procedures to fill gaps/voids in bony structures and for local delivery of antibiotics. The case highlights the importance of careful review of a patient's hospital course, including the administration of medical products that may not be clearly documented on a patient's medicine administration record when working up an unexplained finding.

The role of antibiotic calcium sulfate beads in acute periprosthetic knee infection: a retrospective cohort study

Background

The study aimed to compare debridement, antibiotics, and implant retention (DAIR) vs. debridement antibiotic bead and retention of the implant (DABRI) in terms of infection-free success rate and treatment cost for acute periprosthetic joint infections after total knee arthroplasty (TKA).

Method

Between 2017 and 2020, 32 patients with acute periprosthetic joint infection who were treated by total knee arthroplasty were retrospectively reviewed. The patients were divided into a DAIR group (n=15) and a DABRI group (n=17). During the DABRI, additional calcium ulphate antibiotic beads were used. Patient age, the Musculoskeletal Infection Society score, microorganisms involved, and success rate were assessed.

Results

The mean age of DAIR group (n=15) was 69 years, with 7 being male, and 8 female. The mean follow-up period lasted 30 months. The success rate was 80% (12/15). The mean age of DABRI group (n=17) was 64 years, with 10 patients being male and 7 female. The mean follow-up period was 16 months. The success rate was 88% (15/17). There were no significant differences in patient age (P>0.05), the Musculoskeletal Infection Society score (P>0.05), and success rate (P>0.05). A significant difference was found in the follow-up period between the two groups (P<0.05).

Conclusion

Both DAIR and DABRI could be used to treat acute periprosthetic joint infections and the outcomes and treatment costs of the two procedures were comparable. Additional use of calcium sulfate beads was safe, but might not improve the treatment result. Randomized controlled studies are warranted for the routine use.

Utilisation of calcium sulphate beads in one-stage aseptic revision total hip arthroplasty

INTRODUCTION

Periprosthetic joint infection (PJI) affects many revision total hip arthroplasty (THA) patients, contributing to a concomitant rise in revision costs. Means of decreasing the risk of PJI include the use of antibiotic adjuncts, such as calcium sulphate beads (CSBs). Mixed with antibiotics, the potential benefits of CSBs include dissolvability and antibiotic drug elution. However, information comparing them in aseptic revision is scarce. Therefore, this study investigated CSB utilisation for infection prevention in aseptic revision THA. Specifically, we compared (1) infection rates; (2) lengths of stay; (3) subsequent infection procedures; and (4) final surgical outcome in 1-stage aseptic revision THA patients who did received CSBs to 1-stage aseptic revision THA patients who did not.

METHODS

A retrospective chart review was performed to identify all patients who underwent an aseptic revision THA between January 2013 and December 2017. Patients who received CSBs (n = 48) were compared to non-CSB patients (n = 58) on the following outcomes: postoperative infections, lengths of stay (LOS), subsequent irrigation and debridements (I+Ds), and final surgical outcome, classified as successful THA reimplantation, retained antibiotic spacer, or Girdlestone procedure. Chi-square and t-testing were used to analyse the variables.

RESULTS

There was no significant differences found between CSB patients and non-CSB patients in postoperative infections (p = 0.082), LOS (p = 0.179), I+Ds (p = 0.068), and final surgical outcome (p = 0.211).

CONCLUSION

This study did not find any statistical difference between CSBs and standard of care in infection rates and surgical outcomes. The advantage of these beads for 1-stage aseptic revisions is questionable.

The Incidence of Severe Hypercalcaemia-Induced Mental Status Changes in Patients Treated with Antibiotic-Loaded Calcium Sulphate Depot for Orthopaedic Infections

Local application of antibiotics with calcium-containing carrier materials (CCCM) might deliver large quantities of calcium, with some cases of hypercalcaemia reported. The incidence of symptomatic hypercalcaemia was estimated retrospectively in a consecutive, prospective series of patients treated between 10/2006 and 02/2019 with antibiotic-loaded CCCM for various orthopaedic infections. Risk factors were analysed. In the study period, 215 CCCM applications were performed. Two patients (0.9%) developed symptomatic hypercalcaemia. In one case, hypercalcaemia occurred 14 days after a second CCCM application during a staged septic hip revision. In the other case, hypercalcaemia became symptomatic six days after application of vancomycin-loaded CCCM in a component-retaining septic revision hip arthroplasty. In both cases, hypercalcemia was not imputable solely to the CCCM. Prolonged immobilization, renal impairment and other specific risk factors were present. Implantation of a CCCM for local application of antibiotics exposes the patient to large quantities of calcium during dissolution. This might induce symptomatic hypercalcaemia, a potentially life-threatening complication. The observed incidence of symptomatic hypercalcaemia remained rare (<1%). In some patients, compensatory mechanisms might be overwhelmed in the presence of other risk factors. Postoperative monitoring of calcaemia as well as elimination of risk factors is mandatory for all patients treated with CCCM.

In vitro efficacy of antibiotic loaded calcium sulfate beads (Stimulan Rapid Cure) against polymicrobial communities and individual bacterial strains derived from diabetic foot infections

Introduction. Diabetic foot infection (DFI) is the main reason for diabetes-related hospitalisation and is a major cause of diabetes-related amputation. DFIs are often complicated by ischaemia in the affected limb, the presence of polymicrobial biofilms and increasingly the occurrence of antibiotic resistant bacteria.Hypothesis/Gap statement. Antibiotic loaded beads could inhibit the growth of polymicrobial DFI communities with differing compositions in vitro.Aim. This study investigates the in vitro efficacy of antibiotic loaded calcium sulfate beads (Stimulan Rapid Cure, Biocomposites Ltd., UK) against polymicrobial DFI communities and individual bacterial strains derived from DFIs.Methodology. Debrided tissue obtained from the base of infected diabetic foot ulcers was homogenised and spread over the surface of Columbia blood agar (CBA) and fastidious anaerobe agar (FAA) plates. Calcium sulfate beads containing a combination of vancomycin and gentamicin were then placed on the surface of the agar and following incubation, zones of inhibition (ZOI) were measured. For individual bacterial strains isolated from the infected tissue, calcium sulfate beads containing vancomycin, gentamicin, flucloxacillin or rifampicin and beads containing a combination of vancomycin and gentamicin or flucloxacillin and rifampicin were tested for their ability to inhibit growth.Results. Calcium sulfate beads loaded with a combination of vancomycin and gentamicin were able to inhibit bacterial growth from all polymicrobial tissue homogenates tested, with ZOI diameters ranging from 15 to 40 mm. In the case of individual bacterial strains, beads containing combinations of vancomycin and gentamicin or flucloxacillin and rifampicin were able to produce ZOI with Gram-positive facultatitive anaerobic strains such as Staphylococcus aureus and Enterococcus faecalis, Gram-negative facultative anaerobic strains such as Pseudomonas aeruginosa and obligate anaerobic strains such as Finegoldia magna even where acquired resistance to one of the antibiotics in the combination was evidenced.Conclusion. The local use of calcium sulfate beads containing a combination of two antibiotics demonstrated high efficacy against polymicrobial DFI communities and individual DFI bacterial strains in in vitro zone of inhibition tests. These results show promise for clinical application, but further research and clinical studies are required.

Simulated large joint fluid model for evaluating intra-articular antibiotic delivery systems: initial evaluation using antibiotic-loaded calcium sulfate beads

Introduction: Local antimicrobial delivery via calcium sulfate (CaSO4) beads is used as an adjunctive treatment for periprosthetic joint infection. There is limited clinical information describing the performance of antimicrobial-loaded CaSO4 (ALCS) in large-scale applications. We developed a simulated large joint model to study properties of eluting ALCS. Methods: The in vitro testing platform was an adapted standardized model for tribological testing of prosthetic total hips and total knees (ASTM F732). The model was 70 mL total fluid volume, 25 % bovine serum, and 75 % phosphate-buffered saline, using ISO standard 14242-1 for human synovial fluid simulation. Four brands of CaSO4 were evaluated. Each 10 mL of CaSO4 was loaded with 1.2 grams (g) of tobramycin and 1 g of vancomycin powders. A 35 mL bead volume, equaling 175 beads, of each product was placed in incubated flasks. The test period was 6 weeks with scheduled interval fluid exchanges. Fluid samples were tested for antibiotic and calcium concentrations and pH. Results: Antibiotic elution showed an initial burst on Day 1, followed by a logarithmic reduction over 1 week. Tobramycin fully eluted within 2.5 weeks. Vancomycin showed sustained release over 6 weeks. Calcium ion concentrations were high, with gradual decrease after 3 weeks. All four CaSO4 products were inherently acidic. Fluid became more acidic with the addition of antibiotics primarily driven by vancomycin. Discussion: Clinicians should be cognizant of tobramycin elution burst with ALCS in large loads. The main driver of acidic pH levels was vancomycin. We propose that joint complications may result from lowered fluid acidity, and we suggest clinical study of synovial pH.

Profound Hypercalcemia Associated with Acute Toxic-Metabolic Encephalopathy After Calcium Sulfate Bead Use: A Case Report

CASE

We present the case of an 81-year-old woman who developed profound hypercalcemia requiring admission to the intensive care unit after calcium sulfate bead use during revision hip arthroplasty. The patient's serum calcium level peaked at 21.0 mg/dL and was associated with acute encephalopathy. After treatment with calcitonin and bisphosphonates, her serum calcium level normalized and her mentation improved.

CONCLUSION

The risk of clinically significant hypercalcemia should be considered when using calcium sulfate during orthopaedic surgery.

Do Antibiotic-Loaded Calcium Sulfate Beads Improve Outcomes After Debridement, Antibiotics, and Implant Retention? A Matched Cohort Study

Background

Dissolvable antibiotic-loaded calcium sulfate beads are used as an intraoperative adjunct during debridement with antibiotics and implant retention (DAIR) for periprosthetic joint infections (PJI) to reduce the historically higher failure rates than one- or two-stage exchange. This study evaluated clinical outcomes after DAIRs performed with and without these antibiotic beads. The primary outcome was post-DAIR failure secondary to recurrent PJI at 2 years. The secondary outcome was early failure secondary to recurrent PJI within 90 days.

Material and methods

DAIRs performed for acute or acute hematogenous PJI at a single institution were retrospectively identified between 2013 and 2018. All DAIRs with adjunctive antibiotic beads (cases) were then exactly matched to a cohort of DAIRs without beads (controls) based on Charlson Comorbidity Index. The McNemar’s test and Wilcoxon signed-rank test were used to evaluate differences in outcomes and patient characteristics.

Results

Twenty DAIR cases (with antibiotic beads) were matched with 20 DAIR controls. There was no difference in age, sex, body mass index, joint, erythrocyte sedimentation rate, C-reactive protein, microbiology profile, antibiotic-resistance profile, or intraoperative lavage adjuncts between groups. There were no statistically significant differences between cases and controls for either overall infection-related failure at 2 years (P = .21) or early infection-related failure at 90 days (P = 1.00).

Conclusion

Adjunctive dissolvable antibiotic-loaded calcium sulfate beads did not reduce the incidence of recurrent PJIs at 2 years or 90 days postoperatively after DAIR. Given the added cost of these antibiotic dissolvable beads without clinical benefits, we cannot recommend their use as an adjunct treatment during DAIRs.

Antibiotic-loaded calcium sulfate in clinical treatment of chronic osteomyelitis: a systematic review and meta-analysis

Background

Present work was aimed to gather accessible evidence on the eradication rates and related postoperative complications of antibiotic-loaded calcium sulfate (CS) as an implant in the treatment of chronic osteomyelitis (COM).

Methods

Databases including PubMed, EMBASE, Medline, Ovid and Cochrane library were searched from their dates of initiation until November 2021. Two independent authors scrutinized the relevant studies based on the effectiveness of radical debridement combined with antibiotic-loaded CS for COM; data extraction and quality assessment of the Methodological Index for Non-Randomized Studies (MINORS) criteria were also performed by the authors. In addition, clinical efficacy mainly depended on the evaluation of eradication rates and complications, and all the extracted data are pooled and analyzed by STATA 16.0.

Results

A total of 16 studies with 917 patients (920 locations) were recruited, with an overall eradication rate of 92%. Moreover, the overall reoperation rate, overall refracture rate, overall delayed wound healing rate, and the rate of aseptic wound leakage were 9.0%, 2.0%, 20.0%, and 12.0%, respectively. Moreover, the choice of tobramycin-loaded CS or vancomycin combined with gentamicin-loaded CS did not affect the eradication rate, and the incidence of postoperative complications in COM patients (all $$P>0.05$$ P > 0.05 ). The general quality of the included studies was fair.

Conclusions

Our meta-analysis indicated that the overall eradication rate of COM treated with antibiotic-loaded CS was 92%. Delayed healing is the most common postoperative complication. The choice of tobramycin-loaded CS or vancomycin combined with gentamicin-loaded CS did not affect the eradication rate and the incidence of postoperative complications in COM patients.

Hypercalcemia in a 67-Year-Old Female Following the Use of Calcium Sulfate Beads: A Case Report and Review of Literature

While the milk-alkali syndrome is traditionally viewed as the sole cause of exogenous hypercalcemia, the wide use of calcium sulfate (CS) in orthopedic procedures introduced another important item to be considered in the differential diagnosis. Calcium sulfate beads are increasingly used as void fillers and prophylactic measures to prevent postoperative hardware infections. However, hypercalcemia secondary to rapid calcium absorption from calcium sulfate beads is generally an underrecognized adverse effect and likely underreported. Furthermore, with calcium sulfate beads, hypercalcemia can dramatically present with alteration in mental status. In this report, we present a case of a 67-year-old female who underwent two orthopedic procedures, where calcium sulfate beads were used in both. The patient, on both occasions, developed significant hypercalcemia, manifested as agitation and suicidal thoughts, with each episode resolving after proper hydration and lowering of serum calcium. Also, in this report, we examined the literature and highlighted the female predominance in the reported cases, often manifesting in postoperative day (POD) 4. Given the acuity and severity of hypercalcemia, it is paramount to anticipate hypercalcemia, monitor serum calcium postoperatively to allow timely interventions, and avoid potentially serious complications.

Rare Causes of Hypercalcemia

This article discusses rare causes of hypercalcemia. Hypercalcemia can rarely be associated with immobilization, genetic diseases in children such as Williams-Beuren syndrome, Hypophosphatasia, Jansen Metaphyseal Chondrodysplasia (JMC), cosmetic injection, milk-alkali syndrome (MAS), calcium sulfate beads administration, manganese intoxication, postacute kidney failure recovery, and Paget's disease.

Wound Leakage With the Use of Calcium Sulphate Beads in Prosthetic Joint Surgeries: A Systematic Review

Since its first use as a bone void filler at the end of the 19th century, calcium sulphate products have been adapted in different ways to aid orthopaedic surgeons. Calcium sulphate local antibiotic delivery systems offer a promising solution in the delivery of high antibiotic concentrations locally for an extended period of time. Over the years, multiple centres have reported side effects such as wound drainage, heterotrophic ossification and hypercalcaemia. This study was carried out to assess the risk of wound drainage in prosthetic joints after implantation of antibiotic-impregnated calcium sulphate beads. Two reviewers searched the literature in three online databases using the Cochrane methodology for systematic reviews. The search of databases yielded 182 articles. The studies without reported post-operative complications, mainly drainage outcomes, were excluded. After screening, seven articles were deemed suitable and selected. Out of the 1,112 cases identified, 43 joints developed wound drainage after calcium sulphate bead placement. This complication was resolved in all these cases by either conservative or operative approaches. The factors implicated in the development of wound drainage include the volume of the product used, procedural placement and host factors. The result of this systematic review shows that calcium sulphate products can be used for treatment and prophylaxis in prosthetic joints with a risk of post-procedural wound drainage. This risk, however, is lesser with the use of synthetic calcium sulphate products as compared with conventional calcium sulphate products.

The Risk of Iatrogenic Hypercalcemia in Patients Undergoing Calcium Sulphate Beads Implantation in Prosthetic Joint Surgery: A Systematic Review

Calcium sulphate beads are increasingly being used in the management of prosthetic joint infections (PJI). Traditionally their use was limited to a void or dead space-filling combined with other additives such as Hydroxyapatite. Over the last decade, they have been developed to act more frequently as an antibiotics delivery system. Stimulan, a bio-absorbable form of Calcium sulfate, theoretically has an increased risk of hypercalcemia. Over the last few years, there have been published case reports which report it as an isolated cause of iatrogenic hypercalcemia. The sparsity of literature on this topic makes it difficult for surgeons to decide on the use of Calcium sulphate beads in patients with hypercalcemia predisposition in conditions like autoimmune disorders, sarcoidosis, malignancy, granulomatous diseases, heterotopic ossification, and hyperparathyroidism. The study was performed to assess the risk of hypercalcemia in patients after Calcium sulphate beads implantation in PJI. Two reviewers searched relevant literature in 3 online databases using cochrane methodology for systematic reviews. Studies reporting complications with the use of calcium sulphate beads in prosthetic joints were included. Studies reporting on less than five patients and studies reporting use in any other surgeries were excluded. The search of databases resulted in a total of 96 articles. After screening, a total of four articles were deemed suitable to be included in the analysis. A total of 1049 patients underwent calcium sulfate beads implantation, out of which 44 (4.2%) reported hypercalcemia with 41 (3.91%) transient in nature and 3 (0.28%) required management, including one with ICU admission. The result of this systematic review shows that calcium sulphate beads are safe and effective against PJI. There is a significant risk of transient hypercalcemia in susceptible patients and a low risk of symptomatic hypercalcemia.

Rare Causes of Hypercalcemia: 2021 Update

CONTEXT

Primary hyperparathyroidism and malignancy are the etiologies in 90% of cases of hypercalcemia. When these entities are not the etiology of hypercalcemia, uncommon conditions need to be considered. In 2005, Jacobs and Bilezikian published a clinical review of rare causes of hypercalcemia, focusing on mechanisms and pathophysiology. This review is an updated synopsis of rare causes of hypercalcemia, extending the observations of the original article.

EVIDENCE ACQUISITION

Articles reporting rare associations between hypercalcemia and unusual conditions were identified through a comprehensive extensive PubMed-based search using the search terms "hypercalcemia" and "etiology," as well as examining the references in the identified case reports. We categorized the reports by adults vs pediatric and further categorized the adult reports based on etiology. Some included reports lacked definitive assessment of etiology and are reported as unknown mechanism with discussion of likely etiology.

EVIDENCE SYNTHESIS

There is a growing understanding of the breadth of unusual causes of hypercalcemia. When the cause of hypercalcemia is elusive, a focus on mechanism and review of prior reported cases is key to successful determination of the etiology.

CONCLUSIONS

The ever-expanding reports of patients with rare and even unknown mechanisms of hypercalcemia illustrate the need for continued investigation into the complexities of human calcium metabolism.

Pharmacokinetic and safety assessment of carboplatin-impregnated calcium sulfate hemihydrate beads in eight rats

OBJECTIVE

Evaluate local tissue toxicity and plasma platinum (Pt) in vivo after subcutaneous implantation of carboplatin-impregnated calcium sulfate hemihydrate (CI-CSH) beads.

STUDY DESIGN

In vivo experimental study.

ANIMALS

Eight male Sprague-Dawley rats.

METHODS

CI-CSH beads were implanted subcutaneously (5 mg carboplatin/rat; 13.5 mg/kg carboplatin; 7.08 mg/kg Pt; 1.18 mg/m² Pt) in eight rats (d0). Wound healing (daily), radiographic bead dissolution (weekly), systemic Pt uptake (plasma-Pt), local tissue Pt (d28), and histologic changes compared to nonincised and incised catheterization sites (d28) were assessed. Blood and tissue samples were analyzed by inductively coupled plasma mass spectrometry for Pt, and pharmacokinetic analysis was performed using noncompartmental methods.

RESULTS

One rat died at d10, the remainder survived until d28. No wound complications were seen. The CI-CSH implantation site had higher histopathology scores than the other sites for necrosis (p = .013) and fibrosis (p = .013). Beads decreased in density radiographically (d0 to d28) (p = .062). Peak plasma-Pt concentration was 225.78 ng/ml at 12 h, and decreased over time, but Pt was still detectable on d28. The elimination half-life was 5.03 ± 1.13 days. Only 1.69% of implanted Pt remained in the beads at d28.

CONCLUSIONS

CI-CSH beads incited microscopic mild inflammation but wound healing was not impaired. Pt was absorbed systemically and the release from the beads was near complete at d28.

CLINICAL SIGNIFICANCE

Piled CI-CSH bead implantation is well tolerated in rats with similar elution profile as previously described. Beads were radiographically visible at d28. Minimal Pt was detected systemically suggesting Pt release does not match bead dissolution.

Biomaterials and technologies in the management of periprosthetic infection after total hip arthroplasty: An updated review

Although total hip arthroplasty (THA) is considered one of the most efficacious procedures for managing various hip conditions, failures due to different mechanisms are still being reported. Periprosthetic joint infection (PJI) is one of the devastating causes of failure and revision of THA. PJI carries a burden on the patient, the surgeon, and the health-care system. The diagnosis and management of PJIs carry many morbidities and increased treatment costs. The development of PJI is multifactorial, including issues related to the patient’s general condition, the surgeon’s efficiency, surgical technique, and the implants used. Recent advances in the area of diagnosis and predicting PJI as well as introducing new technologies and biomaterials update for the prevention and treatment of PJI. Local implant coatings, advancement in the bearing surfaces technologies, and new technologies such as immunotherapy and bacteriophage therapy were introduced and suggested as contemporary PJI eradication solutions. In this review, we aimed at discussing some of the newly introduced materials and technologies for the sake of PJI control.

Orthopedic management of pubic symphysis osteomyelitis: a case series

Objectives: The purpose of this case series is to describe the orthopedic management of pubic symphysis osteomyelitis with an emphasis on the key principles of treating bony infection. Furthermore, we sought to identify whether debridement of the pubic symphysis without subsequent internal fixation would result in pelvic instability. Methods: A retrospective chart review was performed to identify all cases of pubic symphysis osteomyelitis treated at both institutions from 2011 to 2020. Objective outcomes collected included infection recurrence, change in pubic symphysis diastasis, sacroiliac (SI) joint diastasis, and ambulatory status. Subjective outcome measures collected included the numeric pain rating scale (NPRS) and the 36-Item Short Form Survey (SF-36). Pubic symphysis diastasis was measured as the distance between the two superior tips of the pubis on a standard anterior–posterior (AP) view of the pelvis. SI joint diastasis was measured bilaterally as the joint space between the ileum and sacrum approximately at the level of the sacral promontory on the inlet view of the pelvis. A paired t test was utilized to compare the differences in outcome measures. An α value of 0.05 was utilized. Results: Six patients were identified, of which five were males and one was female (16.7 %), with a mean ± standard deviation (SD) follow-up of 19 ± 12 months (range 6–37 months). Mean ± SD age was 76.2 ± 9.6 years (range 61.0–88.0 years) and body mass index (BMI) was 28.0 ± 2.9 kg/m2 (range 23.0–30.8 kg/m2). When postoperative radiographs were compared to final follow-up radiographs, there were no significant differences in pubic symphysis diastasis (P = 0.221) or SI joint diastasis (right, P = 0.529 and left, P = 0.186). All patients were ambulatory without infection recurrence at final follow-up. Mean improvement for NPRS was 5.6 ± 3.4 (P = 0.020) and mean improvement for SF-36 physical functioning was 53.0 ± 36.8 (P = 0.032). Conclusion: This case series highlights our treatment strategy for pubic symphysis osteomyelitis of aggressive local debridement with local antibiotic therapy. Additionally, debridement of the pubic symphysis without subsequent internal fixation did not result in pelvic instability, as determined by pelvic radiographs and ability to fully weight bear postoperatively.

Review of calcium-sulphate-based ceramics and synthetic bone substitutes used for antibiotic delivery in PJI and osteomyelitis treatment

Infection in orthopaedic and trauma surgery remains a destructive complication with particularly challenging diagnosis and treatment due to bacterial antibiotic resistance and biofilm formation.

Along with surgical debridement and systemic antibiotics, an important type of adjuvant therapy is local antibiotic delivery, with the purpose of eliminating bacterial colonization and biofilm development.

Calcium sulphate, as a synthetic absorbable biomaterial used for local antibiotic delivery, has experienced an increasing popularity during the last decade, with multiple promoted advantages such as predictable antibiotic elution kinetics, complete and quick biodegradation, good biocompatibility, and limited associated complications.

A series of commercially available antibiotic-delivery systems based on calcium sulphate are under investigation and in clinical use, with different presentations, compositions, and application techniques.

The current article presents the main available calcium-sulphate-based products and the existing data about the clinical and preclinical research results, stemming from their implementation as local antibiotic carriers for surgical site and implant-associated infections treatment and prevention.

Cite this article: EFORT Open Rev 2021;6:297-304. DOI: 10.1302/2058-5241.6.200083

Outcome of Irrigation and Debridement With Topical Antibiotics Delivery for the Management of Periprosthetic Joint Infection Occurring Within 3 Months Since the Primary Total Joint Arthroplasty

BACKGROUND

Irrigation and debridement with modular component exchange is appealing for surgeons to treat early-stage periprosthetic joint infection (PJI). However, the indication, perioperative protocol, and success rate remain controversial. This study is the first one to present results of debridement, antibiotics, and implant retention (DAIR) with integrated MIT (modular component exchange, povidone-iodine and topical antibiotics delivery) protocol for treating PJI occurring within 3 months since the primary total joint arthroplasty.

METHODS

We retrospectively analyzed patients who received DAIR with MIT protocol in our department between January 2011 and May 2018. Topical antibiotics were delivered in all cases. Topical antibiotics infusion was applied for those infected with multidrug-resistant bacteria, fungus, polymicrobial infection, and culture negative one. Failure was defined as additional surgical intervention for infection after DAIR; persistent sinus tract, drainage or excessive joint pain; need for suppressive antibiotics therapy due to the infection; infection relapse with the same pathogen; reinfection with different microorganism; and infection-related death.

RESULTS

A total of 73 patients with a mean age of 63.30 ± 10.97 years were included in this study, including 43 men and 30 women. There are 41 knees and 32 hips. Thirty patients had sinus tract. With a mean follow-up of 63.79 ± 18.57 months, there were 9 failures in total with an overall success rate of 87.67%. The success rate was 88.57% and 86.84% for those receiving topical antibiotics infusion postoperatively and those without.

CONCLUSIONS

DAIR with a standard MIT protocol is a viable and safe option for PJI occurring within 3 months since the primary total joint arthroplasty.

LEVEL OF EVIDENCE

Level 4, therapeutic study.

Calcium sulfate antibiotic-impregnated bead implantation for deep surgical site infection associated with orthopedic surgery in small animals

OBJECTIVE

To report the outcomes and complications associated with antibiotic-impregnated calcium sulfate beads for prevention and treatment of orthopedic-related surgical site infection (SSI) in companion animals.

STUDY DESIGN

Retrospective case series.

ANIMALS

Client-owned cats (n = 2) and dogs (n = 14).

METHODS

Medical records of 16 cases in which implantation of antibiotic-impregnated calcium sulfate beads was performed for the prevention or treatment of SSI were reviewed. Information collected included signalment, prior surgery, reason for bead placement, antibiotics used, bacterial culture results, and clinical outcomes.

RESULTS

Surgical site infection resolved in six of 10 animals treated therapeutically and did not occur in six of six animals treated prophylactically. Susceptibility of the causative bacteria to the antibiotic implanted was confirmed in five of six cases with resolved SSI treated therapeutically but in only one of four cases with unresolved SSI treated therapeutically. Complications directly related to bead placement were evident in only one case in which beads extruded from external skeletal fixator pin tracts 7 days after implantation. At final follow-up, 11 of 12 animals without SSI had satisfactory limb use and no clinical, cytologic, or radiographic evidence of infection.

CONCLUSION

Implantation was well tolerated. Resolution of SSI was inconsistent; however, when bacteria were susceptible to the antibiotic implanted, SSI resolved in all but one case.

CLINICAL SIGNIFICANCE

Antibiotic-impregnated calcium sulfate beads could be considered for prevention or treatment of orthopedic SSI in small animals. A prospective clinical study is required to obtain additional information, including the value of preoperative bacterial culture.

Prevention of Periprosthetic Joint Infection (PJI): A Clinical Practice Protocol in High-Risk Patients

Background: Periprosthetic joint infection (PJI) represents 25% of failed total knee arthroplasties (TKA). The European Knee Associates (EKA) formed a transatlantic panel of experts to perform a literature review examining patient-related risk factors with the objective of producing perioperative recommendations in PJI high-risk patients. Methods: Multiple databases (Pubmed/MEDLINE, EMBASE, Scopus, Cochrane Library) and recommendations on TKA PJI prevention measures from the International Consensus Meetings on PJI from the AAOS and AAHKS were reviewed. This represents a Level IV study. Results: Strong evidence was found on poor glycemic control, obesity, malnutrition, and smoking being all associated with increased rates of PJI. In the preoperative period, patient optimization is key: BMI < 35, diet optimization, Hemoglobin A1c < 7.5, Fructosamine < 292 mmol/L, smoking cessation, and MRSA nasal screening all showed strong evidence on reducing PJI risk. Intraoperatively, a weight-based antibiotic prophylaxis, accurate fluid resuscitation, betadine and chlorhexidine dual skin preparation, diluted povidone iodine solution irrigation, tranexamic acid administration, and monofilament barbed triclosan-coated sutures for soft tissues closure all represented effective prevention measures. In the postoperative period, failure to reach normalization of ESR, CRP, D-dimer, and IL-6 six weeks postoperatively suggested early PJI. Conclusion: The current recommendations from this group of experts, based on published evidence, support risk stratification to identify high-risk patients requiring implementation of perioperative measures to reduce postoperative PJI.

Salvage procedure for chronic periprosthetic knee infection: the application of DAIR results in better remission rates and infection-free survivorship when used with topical degradable calcium-based antibiotics

PURPOSE

Debridement, systemic antibiotics and implant retention (DAIR) is very successful for early periprosthetic joint infection (PJI), but can fail in late-onset cases. We selected patients with PJI who were unsuitable for two-stage exchange total knee arthroplasty (TKA) and compared the outcomes of DAIR with or without degradable calcium-based antibiotics.

METHODS

All patients fulfilled the criteria for late-onset PJI of TKA, as defined by an International Consensus Meeting in 2013, but were unsuitable for multistage procedures and TKA exchange due to operative risk. Fifty-six patients (mean age: 70.6 years, SD ± 10.8), in two historical collectives, were treated using a single-stage algorithm consisting of DAIR without antibiotics (control group, n = 33, 2012-2014), or by DAIR following the implantation of degradable antibiotics as indicated by an antibiogram (intervention group, n = 23, 2014-2017). OSTEOSET^® (admixed vancomycin/tobramycin), and HERAFILL-gentamicin^® were used as carrier systems. The primary endpoint was re-infection or surgical intervention after DAIR.

RESULTS

There were no significant differences between the two groups in terms of mean age, Charlson comorbidity index or the rate of mixed infections. Overall, 65.2% of patients achieved remission in the intervention group compared with only 18.2% in the control group (p < 0.001); 50% of re-infections in the intervention group even occurred after 36 months. Kaplan-Meier analysis showed that, compared with controls, the intervention group experienced significantly longer 3-year infection-free survival.

CONCLUSION

DAIR shows poor efficacy in difficult-to-treat cases, as demonstrated in our control group, which had a re-infection rate of 81.8%. In contrast, a DAIR group receiving topical calcium-based antibiotics showed significantly higher 3-year infection-free survival. Therefore, the combination of DAIR and degradable antibiogram-based local antibiotics is a reasonable salvage procedure for this body of patients. This is important as the number of severely sick patients who are too old for appropriate PJI treatment is estimated to increase significantly due to demographic change.

Complication rates are low with the use of Stimulan calcium sulphate based antibiotic delivery system in the management of patients with hip-related PJI: early results of a consecutive case series

BACKGROUND

Effective management of prosthetic joint infection (PJI) requires prolonged, sustained delivery of antibiotics to the effective joint space. Calcium sulphate antibiotic delivery systems have been used in this setting, however, potentially serious complications including symptomatic hypercalcaemia have been described. There is relatively little prospective data on the results with the use of these compounds.

METHODS

A prospective study was performed between October 2016 and June 2018. 29 patients who underwent revision total hip arthroplasty (THA) for confirmed PJI were treated with Stimulan calcium sulphate antibiotic delivery system. Laboratory blood tests including serum calcium levels, C-reactive protein (CRP) and white cell count (WBC) were monitored for 6 weeks post-surgery. Wounds were assessed for discharge and radiographs for dissolution and for signs of heterotopic ossification.

RESULTS

The mean age was 67 years and mean ASA score III. There was no significant increase between the preoperative serum calcium and those at 2 and 6 weeks. The CRP and white cell count were significantly reduced at 6 weeks. Full dissolution occurred by 6 weeks post-op. 1 patient (3.4%) had a prolonged wound discharge.

CONCLUSIONS

Stimulan is a valid option for management of patients with PJI following total hip arthroplasty. Complication rates are low following its use.

Debridement, antibiotic pearls, and retention of the implant in the treatment of infected total hip arthroplasty

In this article the authors describe a modified surgical technique developed to enhance the classical irrigation and debridement procedure to improve the possibilities of retaining a total hip arthroplasty (THA) undergoing acute periprosthetic joint infection (PJI). This technique, debridement antibiotic pearls and retention of the implant (DAPRI), aims to remove the intra-articular biofilm allowing a higher and prolonged local antibiotic concentration by using calcium sulphate antibiotic-added beads. The combination of 3 different surgical techniques (tumour-like synovectomy, Argon Beam application and chlorhexidine gluconate brushing) might enhance the disruption and removal of the bacterial biofilm which is the main responsible of antibiotics and antibodies resistance. The timing of the diagnosis (6 weeks from the original surgery or 1 week from clinical symptoms appearance in the case of an hematogenous infection) and the preoperative isolation of the germ are fundamental in order to obtain a satisfactory outcome. A 12-week course of postoperative antibiotic therapy (6 weeks I.V. and 6 weeks oral) complete the postoperative protocol used by the authors.The DAPRI technique might represent a safe and more conservative treatment for acute and early hematogenous PJI.

Single-stage debridement with implantation of antibiotic-loaded calcium sulphate in 34 cases of localized calcaneal osteomyelitis

Background and purpose - The successful eradication of calcaneus infection with limb salvage remains a challenge. We describe the outcomes of cortical bone windowing followed by eggshell-like debridement and implantation of antibiotic-loaded calcium sulphate (CS) for localized (Cierny-Mader type III) calcaneal osteomyelitis (CO).Patients and methods - We report a retrospective study of 34 patients. Infection followed trauma or orthopedic surgery in 30 patients and hematogenous spread in 4 patients. 31 patients had a sinus tract, accompanied by a soft tissue defect in 3 patients. All patients received cortical bone windowing, debridement, multiple sampling, local implantation of vancomycin- and gentamicin-loaded CS, skin closure or flap coverage, and culture-specific systematic antibiotic treatment in a single-stage procedure. Patients were followed up for a median of 26 months.Results - Infection was eradicated in 29 patients after the single-stage surgery, and all of the 5 recurrent infections were cleared by repeated surgery without amputation. Other adverse events included 11 patients with aseptic wound leakage and 1 unrelated death. Compared with those before surgery, the median postoperative scores of the American Orthopaedic Foot & Ankle Society (AOFAS) ankle hindfoot scale (65 vs. 86 vs. 89) and the visual analog scale (VAS) for pain (6 vs. 3 vs. 1) improved at the 1-year and 2-year follow-up.Interpretation - This single-stage protocol, cortical bone windowing, and eggshell-like debridement combined with local implantation of antibiotic-loaded CS is effective in treating type III CO. However, the incidence of aseptic wound leakage is high.

The Use of Calcium Sulphate beads in Periprosthetic Joint Infection, a systematic review

Purpose: To assess the use of calcium sulphate (CS) beads in the management of knee and hip periprosthetic joint infections (PJI) in terms of outcomes, complications and re-infection rates.

Methods: A search of NICE healthcare database advanced search (HDAS) was conducted from its year of inception to October 2019 with the keywords: “Calcium Sulphate Beads” or “Calcium Sulfate Beads” or “Antibiotics beads” or “Stimulan” and “Arthroplasty” or “Hip Replacement” or “Knee Replacement” and “Periprothetic joint infection” or “Debridement, Antibiotics and implant retention” or “Revision”. A quality assessment was performed using the NIH study Quality Assessment Tool for case series.

Results: Out of relevant 74 articles, 5 articles met the inclusion criteria. Variable outcomes and success rates have been reported in most of the patients. A small number of wound discharges and heterotrophic ossification (HO) were reported, which are occasionally symptomatic. Hypercalcemia is identified as a potential risk with the use of CS beads especially with doses over 40 cc per operation. The influence of CS beads on reinfection rate is reported in 4 out of 5 articles. Due to the case-mix and heterogenicity of the patients involved and the causative microorganism reported as well as varied procedures are undertaken including one and two stages revision and Debridement, Antibiotics and implant retention (DAIR), the influence of CS beads varied from high success to poor outcome. The poor outcome is higher if the primary procedure for the management of hip and knee PJI is DAIR rather than full revision.

Conclusions: The use of CS beads in the treatment of PJI is a useful technique in delivering high doses of antibiotics locally. A favourable outcome is reported when antibiotics loaded CS is used as an adjuvant to revision procedure for PJI in hip and knee arthroplasty compared to its use as an adjuvant to DAIR procedure. There has been an increase in complications when higher volumes of beads are used, especially in subcutaneous structures and in high-risk patients. Another possible theoretical and unreported complication of CS beads is accelerating the wear rate in the artificial joint due to the possibility of causing abrasion to the bearing surfaces. The current evidence is not enough to indicate the superiority of antibiotic-loaded CS beads as an adjuvant for the treatment of PJI in Hip and Knee arthroplasty.

Pharmacokinetics of platinum and safety evaluation of carboplatin-impregnated calcium sulfate hemihydrate beads after implantation in healthy cats

OBJECTIVE

To evaluate the pharmacokinetics (PK) of platinum (Pt) and safety of carboplatin-impregnated calcium sulfate hemihydrate (C-I CSH) beads after implantation in healthy cats.

STUDY DESIGN

In vivo experimental study.

ANIMALS

Six healthy adult cats.

METHODS

Three C-I CSH beads were implanted in muscle pockets over the right and left hemithoraces of each cat (~3.9 mg/kg of Pt; 60.4 mg/m² of calculated carboplatin). Hematology and blood chemistry were tested at baseline and 3, 7, 14, and 21 days postimplantation. Serum was analyzed for Pt at specific times from 1 hour to 21 days. Tissue was obtained for histopathology and analysis of Pt at 3, 7, 14, and 21 days at standardized distances from implantation sites.

RESULTS

Platinum was detected in tissues at all times and distances (range, 0.1-4.19 μg/g). Serum Pt increased up to 2.6 hours (3.25 μg/mL) then decreased sharply. Samples containing muscle had higher Pt compared with samples without muscle (P = .004). Mild hypercalcemia was noted in four cats, and mild inflammatory reaction was noted on histopathology of all samples.

CONCLUSION

Platinum was released from C-I CSH beads differentially into surrounding tissues over 21 days. Systemic absorption of Pt was minimal, but mild hypercalcemia occurred.

CLINICAL SIGNIFICANCE

Implantation was well tolerated by healthy adult cats. Securing beads within muscle may limit Pt diffusion to targeted tissue. Although Pt concentrations did not achieve levels reported to be cytotoxic for feline sarcoma cells in culture, results provide evidence to support evaluation of efficacy in the tumor microenvironment of cats with locally invasive cancers.

A Scoping Review on the Use of Antibiotic-Impregnated Beads and Applications to Vascular Surgery

INTRODUCTION

Surgical site infection (SSI) presents a ubiquitous concern to surgical specialties, especially in the presence of prosthetic material. Antibiotic-impregnated beads present a novel and evolving means to combat this condition. This review aims to analyze the quality of evidence and methods of antibiotic bead use, particularly for application within vascular surgery.

METHODS

A systematic scoping review was conducted within Embase, MEDLINE, and the Cochrane Registry of Randomized Controlled Trials. Articles were evaluated by 2 independent reviewers. Level of evidence was evaluated using the Oxford Center for Evidence-Based Medicine Criteria and the Cochrane Risk of Bias Tool for Randomized Controlled Trials.

RESULTS

The search yielded 6951 papers, with 275 included for final analysis. Publications increased in frequency from 1978 to the present. The most common formulation was polymethyl methacrylate; however publications on biodegradable formulations, including calcium sulfate beads, have been published with increasing frequency. Most publications had positive conclusions (94.2%); however, the data was mainly subjective and may be prone to publication bias. Only 11 randomized controlled trials were identified and all but one was evaluated to be at a high risk of bias. The most common indication was for osteomyelitis (52%), orthopedic prosthetic infections (20%), and trauma (9%). Within vascular surgery, beads have been used primarily for the treatment of graft infection, with freedom from recurrence rates being reported from 41% to 87.5%.

CONCLUSIONS

Antibiotic-impregnated beads provide a means to deliver high doses of antibiotic directly to a surgical site, without the risks of parenteral therapy. There has yet to be significant high-level quality data published on their use. There is a large body of evidence that suggests antibiotic beads may be used in SSIs in high-risk patients, prosthetic infections, and other complex surgical infections. Important potential areas of application in vascular surgery include graft infection, prevention of wound infection in high-risk patients, and diabetic foot infection.

PROLONGED HYPERCALCEMIA FROM ANTIBIOTIC-ELUTING CALCIUM SULFATE BEADS

Objective

Calcium sulfate beads (CSBs) are biocompatible hydrophilic crystals that are used to deliver local antibiotics in periprosthetic joint infections. Hypercalcemia after placement of CSBs is uncommon and poorly understood.

Methods

We present the case of a woman who presented with symptomatic hypercalcemia after placement of antibiotic-eluting CSBs.

Results

A 58-year-old, Caucasian woman presented with altered mental status, respiratory failure, and septic shock 2 days after placement of antibiotic-eluting CSBs for a left prosthetic hip infection. Laboratory analysis revealed severe hypercalcemia at presentation. She had no known history of fractures, kidney stones, parathyroid, or calcium disorders. She was not on any medications that could induce hypercalcemia. She was treated with aggressive intravenous hydration and 8 doses of calcitonin. Due to impaired renal function, bisphosphonate was contraindicated. She subsequently became anuric with worsening renal failure and volume overload and the decision was made to initiate dialysis. She received 8 days of continuous renal replacement therapy followed by 2 sessions of hemodialysis which improved her serum calcium levels, mental status, and renal failure with no long-term complications.

Conclusion

Hypercalcemia secondary to the placement of antibiotic-eluting CSBs is rare. Larger volumes of CSBs may contribute to hypercalcemia. In some cases, hypercalcemia can be severe and symptomatic as in the case of our patient. Serum calcium levels should be monitored frequently after placement of CSBs and managed as appropriate.

SEVERE HYPERCALCEMIA AFTER JOINT ARTHROSCOPY: CALCIUM SULFATE BEADS TO BLAME

Objective

To review the diagnosis and clinical course of a woman with severe, symptomatic hypercalcemia resulting from the use of calcium sulfate beads (CSBs) during orthopedic surgery for knee joint infection.

Methods

Clinical and laboratory data are presented.

Results

This is a unique case report of a woman that developed severe hypercalcemia 6 days after knee joint arthroscopy with CSB placement for knee prosthesis infection. Her laboratory data were unrevealing for alternate causes of severe hypercalcemia. Her symptoms and calcium level improved with intravenous fluids and 1 dose of calcitonin.

Conclusion

This case demonstrates a rare but serious side effect of using calcium-based beads as fillers for orthopedic surgeries. It is important for patients and physicians to be aware that severe hypercalcemia can result from CSBs used during orthopedic procedures.

Acute Tubular Necrosis Associated With High Serum Vancomycin and Tobramycin Levels After Revision of Total Knee Arthroplasty With Antibiotic-Containing Calcium Sulfate Beads

We present the case of a 59-year-old male who developed acute tubular necrosis with a serum tobramycin level of 15.9 mg/L after instillation of tobramycin and vancomycin calcium sulfate beads for infected total knee arthroplasty. We emphasize standardizing surgical protocols to mitigate nephrotoxicity based on current efficacy and safety data.

Is Hypercalcemia a Frequent Complication following Local Use of Calcium Sulfate with Antibiotics for the Treatment of Extremity Posttraumatic Osteomyelitis? A Preliminary Study

Background

Previous study had reported hypercalcemia as a frequent complication (20%) following local use of antibiotic-eluting calcium sulfate (CS) during treatment of periprosthetic joint infections (PJIs). However, whether this complication may occur in patients who receive local CS implantation for management of posttraumatic osteomyelitis (OM) remains unclear.

Methods

Between April 2016 and May 2017, we included 55 patients with extremity posttraumatic OM who received local antibiotic-loaded CS therapy. Serum calcium levels were detected preoperatively and on the 1st, 3rd, and 7th postoperative days (PODs). Comparisons were performed regarding serum calcium levels among the four time points and between two different CS volume groups (≤ 20 cc group and > 20 cc group). Additionally, potential associations were examined regarding CS volume and preoperative calcium level with postoperative calcium levels, respectively.

Results

Altogether 46 males and 9 females were included, with a median CS volume of 20 cc. Outcomes showed that prevalence of asymptomatic hypocalcemia was more frequent, with 16.4% before surgery and 60%, 53.8%, and 25% on the 1st, 3rd, and 7th PODs, respectively. Hypercalcemia was not found in any patients, at any time point. In addition, significant differences were identified regarding serum calcium levels among different time points, suggesting significantly decreased calcium levels on the 1st (P < 0.001) and 3rd PODs (P < 0.001) and back to near preoperative level on the 7th POD (P = 0.334). However, no statistical differences were observed regarding serum calcium levels between the two CS volume groups at any time points (P > 0.05). Moreover, no significant links were identified between CS volume and postoperative calcium levels (P > 0.05). Serum calcium levels on the 3rd (P = 0.019) and 7th PODs (P = 0.036) were significantly associated with the preoperative calcium level.

Conclusions

In contrast to what had occurred in PJI patients, asymptomatic hypocalcemia appeared to be more frequent in this cohort with posttraumatic OM. Hypercalcemia may be an infrequent complication before and after local CS use for the treatment of extremity posttraumatic OM.

Use of Stimulan absorbable calcium sulphate beads in revision lower limb arthroplasty: Safety profile and complication rates

Aims

Calcium sulphate has traditionally been used as a filler of dead space arising during surgery. Various complications have been described following the use of Stimulan bio-absorbable calcium sulphate beads. This study is a prospective observational study to assess the safety profile of these beads when used in revision arthroplasty, comparing the complication rates with those reported in the literature.

Methods

A total of 755 patients who underwent 456 revision total knee arthroplasties (TKA) and 299 revision total hip arthroplasties (THA), with a mean follow-up of 35 months (0 to 78) were included in the study.

Results

A total of 32 patients (4.2%) had wound drainage, and this was higher with higher bead volumes and in McPherson grade C patients. There was also a significantly higher bead volume in the 41 patients who developed hypercalcaemia, two of which were symptomatic (p < 0.0001). A total of 13 patients (1.7%) had heterotopic ossification (HO). There was no statistically significant relationship between the development of HO and bead volume (p > 0.05).

Conclusion

The strength of this study lies in the large number of patients and the detailed data collection, making it the most comprehensive report available in the literature on the use of calcium sulphate-based bone substitutes.Cite this article: R. Kallala, W. Edwin Harris, M. Ibrahim, M. Dipane, E. McPherson. Use of Stimulan absorbable calcium sulphate beads in revision lower limb arthroplasty: Safety profile and complication rates. Bone Joint Res 2018;7:570-579. DOI: 10.1302/2046-3758.710.BJR-2017-0319.R1.

Indications and Guidelines for Debridement and Implant Retention for Periprosthetic Hip and Knee Infection

PURPOSE OF REVIEW

Prosthetic joint infection is one the most common causes of revision surgery after hip or knee replacement. Debridement and implant retention (DAIR) is one method of treating these infections; however, significant controversy exists. The purpose of our review was to describe current knowledge about indications, intraoperative/postoperative patient management, and outcomes of DAIR.

RECENT FINDINGS

Patient selection affects the success of DAIR. Medical comorbidities, duration of symptoms, and nature of infectious organism all influence outcomes. Intraoperative techniques such as open arthrotomy, extensive debridement, copious irrigation, and exchange of modular parts remain current standards for DAIR. Postoperative administration of antibiotics tailored to operative cultures remains critical. Antibiotic suppression may increase the success of DAIR. DAIR provides reasonable infection eradication between 50 and 80% with improved outcomes in appropriately selected patients. More research is needed on the use of adjuvant therapies intraoperatively and the role of postoperative antibiotic suppression.

Intraoperative Considerations for Treatment/Prevention of Prosthetic Joint Infection

PURPOSE OF REVIEW

Innovative measures have recently been proposed to prevent periprosthetic joint infection following total hip and knee arthroplasty. We sought to review these recent innovations to determine the reported reduction in periprosthetic joint infection.

RECENT FINDINGS

The most recent literature demonstrates promising results in regard to hydrofiber dressings as an independent risk factor for primary prosthetic joint infection reduction, which in turn is also linked with cost savings. As our understanding of safe yet effective concentrations of antiseptic solutions develops, dilute betadine in particular has demonstrated encouraging efficacy which warrants continued investigation through controlled trials. In summary, we found that the application of a hydrofiber dressing may prove beneficial in decreasing the risk of prosthetic joint infection following primary total hip and knee arthroplasty. The gold standard for an infection prevention protocol continues to be explored and optimized.

Procedure for single-stage implant retention for chronic periprosthetic infection using topical degradable calcium-based antibiotics

INTRODUCTION

Surgical treatment using DAIR (debridement, systemic antibiotics, and implant retention) can lead to high rates of treatment success in cases of early periprosthetic joint infection (PJI) but can fail in late-onset cases. Supplementary local antibiotic therapy is not yet generally established and lacks evidence-based proof of efficacy. The aim of this study was to analyze DAIR outcomes in recurrent PJI cases and patients who are not suitable for a two-stage exchange, using additional degradable calcium-based antibiotics.

METHODS

All patients fulfilled the Infectious Diseases Society of America (IDSA) guidelines for chronic late-onset PJI but were not suitable for a multistage procedure because of their individual operation risk. A total of 42 patients (mean age, 73 years) were treated using a single-stage algorithm consisting of DAIR, followed by implantation of degradable antibiotics chosen in accordance with an antibiogram. OSTEOSET® (admixed ceftriaxone/vancomycin/tobramycin) and Herafill-Gentamycin® were used as carrier systems. The follow-up period was 23 months (± SD, 10.3). The study is based on institutional review board (IRB) approval.

RESULTS

The clinical entities were chronic PJI of the hip (45.2%), knee (28.6%), and knee arthrodesis (26.2%). The bacterial spectrum was composed of Staphylococcus epidermidis (29%), Staphylococcus aureus (21%), and Enterococcus faecalis (21%). 21.4% showed a combination of two or more bacteria. In 73.8%, permanent remission was achieved, while 11.9% showed chronic PJI under implant retention. Implant retention could be achieved in 85.7%.

CONCLUSION

DAIR usually shows low levels of success in difficult-to-treat cases. However, we could demonstrate the successful treatment of patients with recurrent PJI (typically considered DAIR-inappropriate) using degradable antibiogram-based topical calcium-based antibiotics. Over 70% of the cases went to remission and over 85% of the implants could be retained.

Local bio-absorbable antibiotic delivery in calcium sulfate beads in hip and knee arthroplasty

Antibiotic-impregnated calcium sulfate (AICS) beads have been used for prevention and treatment of periprosthetic joint infections. We evaluated post-operative complications following the use of AICS beads. 56 patients undergoing complex primary or revision hip or knee arthroplasty received antibiotic calcium sulfate beads. Primary outcomes were wound complication rates. Secondary outcomes included reoperation and reinfection rates. One case (1.7%) of persistent wound drainage occurred requiring surgical irrigation and a poly-exchange. No post-operative infections were seen. Use of 100% pure calcium sulfate AICS beads may help reduce post-operative wound complications. AICS appears to be a safe adjunct tool in local antibiotic delivery.

Current Options and Emerging Biomaterials for Periprosthetic Joint Infection

PURPOSE OF REVIEW

Infection in the setting of total joint arthroplasty, referred to as periprosthetic joint infection (PJI), is a devastating complication requiring prolonged and costly treatment. The unique environment around an artificial joint and ability of surrounding tissues to sequester bacteria collectively make prevention, diagnosis, and treatment of this condition challenging. In light of the unique pathogenesis of PJI, this review explores the limitations of contemporary treatments and discusses novel treatment options.

RECENT FINDINGS

Recent advancements in local antibiotic delivery platforms for preventing and treating PJI include titanium nanotube arrays, synthetic polymers, resorbable hydrogels, and cyclodextrin-based drug delivery options. In particular, cyclodextrins have facilitated great advancements in other clinical disorders and have demonstrated early promise as a future option in the arena of PJI. Novel treatment modalities for PJI optimize the implant surfaces to prevent bacterial biofilm formation or provide prolonged intra-articular antibiotic dosing to eradicate bacteria.

Static antibiotic spacers augmented by calcium sulphate impregnated beads in revision TKA: Surgical technique and review of literature

Periprosthetic joint infection (PJI) is a serious complication in total knee arthroplasty (TKA) and represents one of the most common causes of revision. The challenge for surgeons treating an infected TKA is to quickly obtain an infection-free joint in order to re-implant, when possible, a new TKA. Recent literature confirms the role of local antibiotic-loaded beads as a strong bactericidal, allowing higher antibiotic elution when compared with antibiotic loaded spacers only. Unfortunately, classical Polymethylmethacrylate (PMMA) beads might allow bacteria adhesion, secondary development of antibiotic resistance and eventually surgical removal once antibiotics have eluted. This article describes a novel surgical technique using static, custom-made antibiotic loaded spacers augmented by calcium sulphate antibiotic-impregnated beads to improve the success rate of revision TKA in a setting of PJI. The use of calcium sulphate beads has several potential benefits, including a longer sustained local antibiotic release when compared with classical PMMA beads and, being resorbable, not requiring accessory surgical interventions.