Aims. Bacterial infection activates neutrophils to release neutrophil extracellular traps (NETs) in bacterial biofilms of periprosthetic joint infections (PJIs). The aim of this study was to evaluate the increase in NET activation and release (NETosis) and haemostasis markers in the plasma of patients with PJI, to evaluate whether such plasma induces the activation of neutrophils, to ascertain whether increased NETosis is also mediated by reduced DNaseI activity, to explore novel therapeutic interventions for NETosis in PJI in vitro, and to evaluate the potential diagnostic use of these markers. Methods. We prospectively recruited 107 patients in the preoperative period of prosthetic surgery, 71 with a suspicion of PJI and 36 who underwent arthroplasty for non-septic indications as controls, and obtained citrated plasma. PJI was confirmed in 50 patients. We measured NET markers, inflammation markers, DNaseI activity, haemostatic markers, and the thrombin generation test (TGT). We analyzed the ability of plasma from confirmed PJI and controls to induce NETosis and to degrade in vitro-generated NETs, and explored the therapeutic restoration of the impairment to degrade NETs of PJI plasma with recombinant human DNaseI. Finally, we assessed the contribution of these markers to the diagnosis of PJI. Results. Patients with confirmed PJI had significantly increased levels of NET markers (cfDNA (p < 0.001), calprotectin (p < 0.001), and neutrophil elastase (p = 0.022)) and inflammation markers (IL-6; p < 0.001) in plasma. Moreover, the plasma of patients with PJI induced significantly more neutrophil activation than the plasma of the controls (p < 0.001) independently of tumour necrosis factor alpha. Patients with PJI also had a reduced DNaseI activity in plasma (p < 0.001), leading to a significantly impaired degradation of NETs (p < 0.001). This could be therapeutically restored with recombinant human DNaseI to the level in the controls. We developed a model to improve the diagnosis of PJI with cfDNA, calprotectin, and the start tail of TGT as predictors, though cfDNA alone achieved a good prediction and is simpler to measure. Conclusion. We confirmed that patients with PJI have an increased level of NETosis in plasma. Their plasma both induced NET release and had an impaired ability to degrade NETs mediated by a reduced DNaseI activity. This can be therapeutically restored in vitro with the approved Dornase alfa, Pulmozyme, which may allow novel methods of treatment. A combination of NETs and haemostatic biomarkers could improve the diagnosis of PJI, especially those patients in whom this diagnosis is uncertain. Cite this article: Bone Joint J 2024;106-B(9):1021–1030

The use of implant biomaterials for prosthetic reconstructive surgery and osteosynthesis is consolidated in the orthopaedic field, improving the quality of life of patients and allowing for healthy and better ageing. However, there is the lack of advanced innovative methods to investigate the potentialities of smart biomaterials, particularly for the study of local effects of implant and osteointegration. Despite the complex process of osseointegration is difficult to recreate in vitro, the growing challenges in developing alternative models require to set-up and validate new approaches. Aim of the present study is to evaluate an advanced in vitro tissue culture model of osteointegration of titanium implants in human trabecular bone. Cubic samples (1.5×1.5 cm) of trabecular bone were harvested as waste material from hip arthroplasty surgery (CE AVEC 829/2019/Sper/IOR); cylindrical defects (2 mm Ø, 6 mm length) were created, and tissue specimens assigned to the following groups: 1) empty defects- CTR-; 2) defects implanted with a cytotoxic copper pin (Merck cod. 326429)- CTR+; 3) defects implanted with standard titanium pins of 6 µm-rough (ZARE S.r.l) -Ti6. Tissue specimens were cultured in mini rotating bioreactors in standard conditions, weekly assessing viability. At the 8-week-timepoint, immunoenzymatic, microtomographic, histological and histomorphometric analyses were performed. The model was able to simulate the effects of implantation of the materials, showing a drop in viability in CTR+, differently from Ti6 which appears to have a trophic effect on the bone. MicroCT and histological analysis supported the results, with lower BV/TV and Tb.Th values observed in CTR- compared to CTR+ and Ti6 and signs of matrix and bone deposition at the implant site. The collected data suggest the reliability of the tested model which can recreate the osseointegration process in vitro and can therefore be used for preliminary evaluations to reduce and refine in vivo preclinical models. Acknowledgment: This work was supported by Emilia-Romagna Region for the project “Sviluppo di modelli biologici in vitro ed in silico per la valutazione e predizione dell'osteointegrazione di dispositivi medici da impianto nel tessuto osseo”

Total temporomandibular joint (TMJ) replacements reduce pain and improve quality of life in patients suffering from end-stage TMJ disorders, such as osteoarthritis and trauma. Jaw kinematics measurements following TMJ arthroplasty provide a basis for evaluating implant performance and jaw function. The aim of this study is to provide the first measurements of three-dimensional kinematics of the jaw in patients following unilateral and bilateral prosthetic TMJ surgeries. Jaw motion tracking experiments were performed on 7 healthy control participants, 3 unilateral and 1 bilateral TMJ replacement patients. Custom-made mouthpieces were manufactured for each participant's mandibular and maxillary teeth, with each supporting three retroreflective markers anterior to the participant's lip line. Participants performed 15 trials each of maximum jaw opening, lateral and protrusive movements. Marker trajectories were simultaneously measured using an optoelectronic tracking system. Laser scans taken of each dental plate, together with CT scans of each patient, were used to register the plate position to each participant's jaw geometry, allowing 3D condylar motion to be quantified from the marker trajectories. The maximum mouth opening capacity of joint replacement patients was comparable to healthy controls with average incisal inferior translations of 37.5mm, 38.4mm and 33.6mm for the controls, unilateral and bilateral joint replacement patients respectively. During mouth opening the maximum anterior translation of prosthetic condyles was 2.4mm, compared to 10.6mm for controls. Prosthetic condyles had limited anterior motion compared to natural condyles, in unilateral patients this resulted in asymmetric opening and protrusive movements and the capacity to laterally move their jaw towards their pathological side only. For the bilateral patient, protrusive and lateral jaw movement capacity was minimal. Total TMJ replacement surgery facilitates normal mouth opening capacity and lateral and inferior condylar movements but limits anterior condylar motion. This study provides future direction for TMJ implant design

Aims

We performed a systematic literature review to define features of patients, treatment, and biological behaviour of multicentric giant cell tumour (GCT) of bone.

Aims

To evaluate safety outcomes and patient satisfaction of the re-introduction of elective orthopaedic surgery on ‘green’ (non-COVID-19) sites during the COVID-19 pandemic.

Post-surgical infections are still one of the most frequent adverse events in the prosthetic surgery. PMMA-based cements are widely employed in orthopaedic surgery as filler or prosthetic fixing device. The main problems associated with this material are poor bone integration and infection development. Aiming to avoid bacterial adhesion and to extend the longevity of implants, different solutions were proposed, both in terms of operative procedures and new materials development. Regarding the materials advancement, innovative PMMA-based composite bone cements, contemporaneously bioactive and antibacterial (without the use of antibiotics), were developed. The composites are based on a PMMA matrix containing a bioactive glass, doped with antibacterial ions (Ag+ or Cu++); so, the same filler shows at the same time the ability of promoting bone ingrowth and an antibacterial effect. Composite cements were characterized in terms of morphology and composition, curing parameters and mechanical properties; in vitro tests were performed to verify the material ability to release antibacterial ions and to promote the precipitation of hydroxyapatite. Moreover, cytotoxicity and antimicrobial properties were verified. The cements characteristics were tested using different commercial matrix and different viscosities; therefore, the proposed formulations represent an innovative solution for a new family of antibiotic-free, bioactive and antibacterial cements

Aim. Prosthetic joint infections (PJI) due to Enterobacter cloacae are rare and often severe. The aim of this study is to describe cases with E. cloacae PJI. Method. We conducted a retrospective and a monocentric study in an orthopedic unit where complex bone and joint infections are managed. From 2012 to 2016, we included patients with PJI which perioperative samples were positive with E. cloacae. We collected background, clinical, biological and microbiological data of the current infection, surgical and medical treatment, and the outcome of these patients. Results. A total of twenty patients were included which 8 were male. Location was hip in 14 cases, knee in 5 cases and ankle in one case. The median time between arthroplasty and revision for infection was 3 years. Fourteen patients had at least two surgeries for previous PJI. The median time between the last surgery and the revision for E. cloacae infection was 31 days. Eleven patients were infected by extended-spectrum beta-lactamases (ESBL) strains. Most frequently, the antibiotics used were carbapenem in 9 cases, cefepim in 7 cases, a quinolone in 7 cases and fosfomycin in 4 cases. Infection was cured in 10 cases (50%) with a median time of follow-up of 24 months. Five patients had a recurrent infection, three due to Staphylococcus epidermidis, one to Staphylococcus epidermidis and Propionibacterium acnes and one to Escherichia coli. Four patients had a relapse of E. cloacae infection. One patient died from non-infectious cause (stroke). Conclusions. PJI infections due to E.cloacae usually occur early after the last prosthetic surgery, typically in patients with complex surgical history. A poor outcome, observed in nearly half of the patients could be explained in part by an association of factors: multiple risks factors, complex infectious history, a high rate of multiple resistance to antibiotics, unfavorable skin conditions

Objectives

Implant-related infection is one of the most devastating complications in orthopaedic surgery. Many surface and/or material modifications have been developed in order to minimise this problem; however, most of the in vitro studies did not evaluate bacterial adhesion in the presence of eukaryotic cells, as stated by the ‘race for the surface’ theory. Moreover, the adherence of numerous clinical strains with different initial concentrations has not been studied.

Aims

Our aim was to analyse the long-term functional outcome of two forms of surgical treatment for active patients aged > 70 years with a displaced intracapsular fracture of the femoral neck. Patients were randomised to be treated with either a hemiarthroplasty or a total hip arthroplasty (THA). The outcome five years post-operatively for this cohort has previously been reported. We present the outcome at 12 years post-operatively.

Aim. When a prosthetic joint infection (PJI) is suspected, guidelines recommend performing periprosthetic samples, at least one for histopathological examination and 3 to 6 for microbiological culture. The diagnosis of infection is based on the presence of neutrophil granulocytes whose number and morphology can be variable, resulting in definition of “acute” inflammation. The acute inflammation of periprosthetic tissue is supportive of infection. Since 2007, in our hospital, for all patients with suspected PJI who underwent surgery, from each sample taken by the surgeon, one part has been sent to the pathologist and the other one to the microbiologist. Our aim was to compare histopathological to microbiological results from samples taken intraoperatively at the same site. Method. We conducted a retrospective study including all surgeries for which at least one couple “histopathology-culture” was found. Exclusion criterion was a history of antimicrobial treatment 2 weeks prior the surgery. Results. From July 2007 to April 2015, 309 surgeries for suspected PJI were performed in 181 patients. Median age of the study population was 70 years, 60% of patients were male, 45% had a history of joint infection. The location of arthroplasty was knee in 50% of cases and hip in 46%, ankle and shoulder in 4%. Surgery was performed within one month after the last prosthetic surgery in 15% of cases. According to the criteria from the Musculoskeletal Infection Society, 60% of cases should have been considered as having an infection. The median number of samples per surgery was 4 (IQR 3–5) for histopathological examination and 5 (IQR 4–6) for culture. Finally, 1247 couples “histopathology-culture” were available. Among them, histopathological examination showed acute inflammation in 292 cases (23%) and subacute inflammation in 327 cases (26%). Microorganisms considered to be pathogenic were found in 582 samples (47%). The presence of neutrophil granulocytes was well correlated with the presence of those microorganisms (OR=4.1; IC 95% 3.1–5.5). As expected, the highest correlation between acute inflammation and positive culture was observed for early infection (< 1 month) (OR = 9; 3.6–23.4) and Staphylococcus aureus infection (OR = 4.8; 3.3–7.0). There was no correlation between acute or low-grade inflammation and anaerobic or Candida infection. Conclusions. Our results confirmed histopathological examination is better correlated with culture in acute infection and/or infection due to highly virulent bacteria but must be interpreted with caution in case of chronic infection or infections due to microorganisms with low virulence

Purpose

To assess the reliability of a biomimetic osteochondral scaffold Maioregen (Finceramica Faenza SpA, Faenza, Italt) as a salvage and joint-preserving procedure in the treatment of late stages of osteonecrosis of the knee.

Shoulder arthroplasty has been performed by many years for the treatment of several conditions such as osteoarthritis, umeral head avascular necrosis and proximal umeral fractures following traumas. Surgical site infection (SSI) following shoulder arthroplasty remains a challenge, which increases morbidity including reoperations, implant removal, poor mobility, and raises extra medical costs. Identification of risk factors may help implementing adequate strategies to prevent infection. We aim to identify pre- and intra-operative risk factors associated with deep infections in shoulder arthroplasty. An age and sex-matched case control study was conducted to describe the prevalence rate, clinical and microbiological findings and to evaluate patient and surgical risk factors for shoulder arthroplasty-associated infections (SAIs), among 158 patients who underwent shoulder replacement surgery due to any reason, from 1988 to 2011 at a tertiary public university institution. To evaluate risk factors from SAI we performed uni- and multivariate analysis by multiple logistic regression. We analyzed 168 prosthetic shoulder replacement surgeries from 158 patients, with an overall infection rate of 9.5%, (16/168 cases). Gram-positive cocci and Gran-negative bacilli were equally isolated in 50% of cases, however the most common bacteria detected (18.8%) was Pseudomonas aeruginosa. Univariate analysis identified neither specific comorbidity nor pre-operative risk factors, but American Society of Anesthesiologists (ASA) score higher than 2 (odds ratio [OR] = 5.30, 95% confidence interval [CI] = 1.58 to 17.79; p=0,013) to be significant preoperative patient-related predisposing factor for SAI. On univariate analysis, the only surgery-related factor significantly associated with higher risk of SAIs was the presence of surgical haematoma (OR = 7.1, 95% CI = 1.1 to 46; p=0.04). On multivariate analysis ASA score higher than two (OR = 4.7, 95% CI = 1.3 to 16.9; p=0.01) was the only independent predictor for periprosthetic shoulder infection. This study identified unusual pathogens and confirmed previously patient-related known factors such as higher ASA score that predispose to SAIs

PJI du to Enterobacter cloacae are rare and often severe. The aim of our study is to define the history of patients with such infections and their outcome. We conducted a retrospective monocentric study in an orthopedic unit where complex bone and joint infections are supported. From 2011 to 214 we selected patients with E. cloacae PJI based on data from the microbiology laboratory. In their files we collected information on their background, their medical and surgical history, antibiotics they received in the year before infection, the suspected portal of entry, the management and the outcome. Twelve patients were included, 7 male and 5 female. PJI was located to the hip in 8 cases, the knee in 3 cases and the ankle in one case. The average time between the placing of the first prosthesis and infection was 3 years. Eleven patients had one or more surgery for previous PJI. The average time elapsed since the last surgery was 30 days. Eleven patients had been treated with antibiotic combinations for at least 6 weeks, in the year before E cloacae infection. A portal of entry was identified only two times: urinary tract infection in one patient and catheter-related infection in one patient. Antibiotics the more often prescribed were carbapenems (n = 5) and cefepime (n = 4), each combined with quinolones (n =4) or fosfomycin (n = 3). Two patients required an additional debridement within an average of 18 days. Infectious outcome was favorable in 8 cases (67%) with a median duration of follow-up of 26 months. Two patients had a recurrent infection, one due to Streptococcus oralis and one to Candida albicans. One patient had a relapse of E cloacae infection. One patient died from unknown cause. PJI infections due to E.cloacae usually occur early after prosthetic surgery, typically in patients with complex surgical history. Despite a high rate of multi-resistance to antibiotics, outcome may be favorable in a large majority of patients

In this case study, we describe the clinical presentation and treatment of 36 patients with periosteal chondrosarcoma collected over a 59-year period by the archive of the Netherlands Committee on Bone Tumours. The demographics, clinical presentation, radiological features, treatment and follow-up are presented with the size, location, the histological grading of the tumour and the survival.

We found a slight predominance of men (61%), and a predilection for the distal femur (33%) and proximal humerus (33%). The metaphysis was the most common site (47%) and the most common presentation was with pain (44%). Half the tumours were classified histologically as grade 1. Pulmonary metastases were reported in one patient after an intra-lesional resection. A second patient died from local recurrence and possible pulmonary and skin metastases after an incomplete resection.

It is clearly important to make the diagnosis appropriately because an incomplete resection may result in local recurrence and metastatic spread. Staging for metastatic disease is recommended in grade II or III lesions.

These patients should be managed with a contrast-enhanced MRI of the tumour and histological confirmation by biopsy, followed by en-bloc excision.

Cite this article: Bone Joint J 2014;96-B:823–8.

From 1998 to July 2003 admissions for elective arthroplasty surgery in Derriford Hospital were nursed alongside other orthopaedic and general medical patients. Since August 2003 a policy of pre-operative MRSA screening and a unit reserved exclusively for MRSA-free joint replacement patients have been used. No transfers from other wards were allowed. Patients positive on screening underwent eradication and were admitted to a different ward where they received teicoplanin on induction (in addition to standard policy cephradine). All post-operative wound infections following THR & TKR were monitored (NINSS surveillance system). Infections within 3 months were recorded. A control of non-screened hip hemi-arthroplasty patients was used to ensure a departmental wide reduction in MRSA was not occurring.

1.9% MRSA carriage rate was detected over the study. Before screening, 0.59% of 3386 cases were acutely infected with MRSA. After institution of screening and a dedicated MRSA free unit, 0.10% of 1034 were acutely infected. This was a 6-fold decrease (p<0.05). The infection noted was in a patient treated outside the ringfenced unit on High Dependency. In fact the infection rate on the ringfenced unit was zero. MRSA infection in the control was statistically unchanged during this period.

Purpose of the study: Increasing the number of times the operating room doors open increases the number of airborne bacteria and consequently the rate of postoperative infections with sometimes disastrous results, particularly for prosthesis surgery. Material and methods: An observer counted the number of times the door to the operating room were opened during orthopaedic operations. The study was conducted in a teaching hospital (hospital A) during scoliosis surgery then repeated for a similar operation after posting dissuasive signs and delivery of information to the personnel concerning the risk of contaminating the patient. A study was then conducted for total hip arthroplasty (THA) in another teaching hospital (hospital B) and in a private clinic (hospital C). The same protocol as used in South Australia was applied for these studies. Results: The mean rate of door opening in hospital A was 0.52/min. This rate was 0.45/min (13.5% less) in the same hospital A after posting dissuasive signs on the doors and providing information to the personnel. In hospital B, the rate was 0.67/min. In hospital C, the rate was 0.42/min (i.e. 37% less). In Australia, the mean rate was 1/min in hospital A before sign posting and information delivery and 0.65 (−35%) after. In hospital B, the rate was 0.87/min and in hospital C 0.47/min (i.e. 46% less). Discussion: Nearly 50 years ago Sir John Charnley demonstrated that airborne contamination must be controlled in prosthetic orthopaedic surgery. In France airborne contamination is regulated by a series of standards (NF EN ISO 14644 established in 1999) and partially controlled during the design phase of operating rooms with the installation of laminar flow ventilation. Door opening, and particularly swinging doors, causes turbulent airflow increasing bacterial contamination. Conclusion: Circulation in the operating room should be limited to necessary organisation (prior transport of instruments and consumables, fluoroscope, nursing staff turnover, etc.) and by information and education of all participants. The presence of observers is inevitable in the operating rooms of teaching hospitals. Their entrance and exit should however be limited and their movement within the room controlled. It is also recommended to use cell phones

Purpose of the study: Prevention of operative site infections (OSI) in orthopaedic surgery requires strict observation of validated practices during hospitalisation and in the operative theatre, review of morbidity and mortality, and surveillance of OSI. Certain intrinsic patient-related risk factors of OSI cannot be controlled without direct implication of the patient and the referring physician. Search for Staphylococcus aureus (SA) colonisation and bacteriuria should be done in the ambulatory setting, before hospitalisation. The purpose of this work was to evaluate the feasibility of a search for SA in the nasal swabs and urine samples in patients scheduled for prosthesis surgery. Material and methods: This was a prospective study on 335 patients who had a total hip arthroplasty (THA) or a total knee arthroplasty (TKA) from January 1, 2007 to December 31, 2008. Bacteriological tests were performed before hospitalisation. Before hospitalisation, the patient and the primary care physician were give information on the proper procedure for chemical decontamination. The results of these laboratory tests were analysed and OSI were followed. Results: Three hundred thirty-five patients (195 THA and 143 TKA) were included; the sex-ratio was 0.95 M/F. Sixty-one patients (18%) exhibited SA colonization, including two meticillin resistant strains. Urine samples were positive in 30/323 patients (9.3%). Three patients presented an early OSI: two infections of a revision THA and one infection of a revision TKA. Two of these patients had an SA infection, including one who was colonized and had applied the chemical decontamination protocol before hospitalization. Discussion: By treating bacteriuria before hospitalization, deferral of the scheduled operations could be avoided. Laboratories must run two sets of tests to search for both met-S and met-R SA, which in our experience was not always the case despite written prescriptions. Implementation of chemical decontamination of the nasal passages and skin before surgery requires a well-established cooperation between the primary care physician and the hospital. The three infections recorded in this series involved revision procedures, with a context of rheumatoid polyarthritis for two patients. Conclusion: Systematic screening for SA colonization in orthopaedic surgery remains a subject of debate, particularly concerning the cost-efficacy balance, but can be quite useful in certain situations such as revision or prosthetic surgery in immunodepressed patients