Introduction. Advantages of ceramic materials for hip joint prosthesis are recognized to be high hardness, scratch resistance, improved wettability, lower friction and lower wear than CoCr surfaces. Recent studies suggest the use of ceramic femoral head reduce fretting corrosion at stem taper junction compared to metal-on-metal taper junction[1]. Continuous improvement of ceramic materials for orthopedic lead to the development of a resurfacing ceramic-on-ceramic hip joint prosthesis. The main differences of resurfacing heads respect to standard heads are their anatomical dimension and the empty shape suitable to cover the femoral bone and to connect with the resurfacing stem. Ceramic is essentially a brittle material and its strength is influenced by the minimum thickness in the stressed area. Ceramic resurfacing head minimum thickness is comparable with ceramic revision head already on the market. The aim of this study is to develop a mechanical pre-clinical analysis verification process for the newly developed system. Materials and methods. The empty shape of the ceramic resurfacing head may influence its strength in a crush loading scenario. Although this is not a physiological condition this test represents the most severe loading for a resurfacing head. Also comparative analysis can be done considering the yield point of conventional metal resurfacing heads reported by the FDA Center for Devices and Radiological Health. For this reason a static unsupported head strength test is performed by applying a compressive load perpendicular to the head axis along the equatorial plane[2](Fig.1). Resurfacing ceramic head made in ZTA is suitable both for a resurfacing stem and an adaptor to be coupled with a standard stem. Mechanical test was performed on worst case resurfacing head size both with resurfacing stem and standard stem based and on FE non linear analysis performed in ANSYS 17.2 according the following material properties: ZTA ceramic (modulus of elasticity E, Poisson ratio ν and density ρ of 348GPa, 0.23 and 4.25g/cm. 3. respectively), and Ti6Al4V (E=114GPa, ν=0.33 and ρ=4.43g/cm. 3. ). For comparison purposes unsupported test was performed on standard head Ø28#S both in Biolox®Delta and Biolox®Forte ceramic. At least three components were used for each test and the average values was compared with predicates[2]. Static compressive load was applied with MTS hydraulic actuators with load cell of 100kN. Results. FE analysis indicated the larger resurfacing head as the worst case size in the size range(Fig.2). Static unsupported head strength test was performed on resurfacing ceramic head Ø57 coupled both with resurfacing stem and standard stem, Biolox®Delta head Ø28#S, Biolox®Forte head Ø28#S and respectively reached a strength value of 53±7kN, 90±3kN, 78±27kN, 49±1kN. Equivalent test were reported in literature for DeltaSurf® Ø58 and BHR. TM. , and respectively reached a strength of 26kN and 5.6kN. Discussion and Conclusion. LIMA ceramic resurfacing head and Biolox Forte Ø28#S showed equivalent unsupported head burst strength. LIMA ceramic resurfacing head showed higher unsupported head burst strength respect to DeltaSurf® and BHR. TM. highlighting its potential in clinical use. For any figures or tables, please contact the authors directly

The authors studied the characteristics that would be desirable for a metacarpo-phalangeal joint prosthesis to be used in patients with rheumatoid disease. In these patients the severe destruction of the capsulo-ligamentous structures of the joint often makes prosthetic substitution dissatisfactory, particularly for the index finger. Such a prosthesis should be restricted in its range of motion, actually abolishing any ulnar deviation. Axial rotaion should be coupled to flexion-extension and radial deviation to gain an adequate stress dissipation at the interface. Both distal and proximal stems should be conical, for the best possible distribution of shear stresses at the interface. A flattening surface should accommodate properly the externsor apparatus without interfering with it. The greatest possible congruence should be required for the articulated components. The rationale of such a design for a rheumatoid patient lies in the fact rheumatoid arthritis is the most important indication for a metacarpo-phalangeal joint arthroplasty, due to the highly incapacitating condition that may ensue. Then, despite limitations required by the proposed design, an improvement in the functional ability of the rheumatoid patient will be obtained

Joint prosthesis infection after post-surgical intervention is an emergency. Infection development and progression are inherently dependent on the process of angiogenesis. Many immune disorders are associated with circulating natural antibodies, which bind self-protein as angiogenin (ANG). Biomarkers as anti-ANG IgA show a predisposition for infection development and must be attended by the strategies for therapeutic interventions. To determine the relationship between the serum levels of anti-ANG IgA and risk of post-surgical joint prosthesis infection (JPI). We have developed a ELISA, in which ANG coupled to high-molecular weight matrix (polyphenylacrylate) was coated on microtiter plates. Human serum samples were incubated in the plates, after which bound anti-ANG IgA was detected with mouse anti-human IgA-HRP. The optimal sensitivity and specificity of the assay was 91% and 84%. The specificity of ELISA was confirmed by the immunoprecipitation/immunoblotting control experiments. Serum levels of anti-ANG IgA in a cohort of healthy donors differed by more than a hundred-fold, whereas the fluctuation of anti-ANG IgA levels in individuals over time was small (coefficient of variation 6%). The study began in October 2005 and finish December 2008. For first study samples were collected from Department of Hip and Knee Articular Reconstruction. In this period we have operated 1290 patients with joint prostheses implanted. A second study examined specimens collected in Department of Bone Infections from 119 patients with JPI. In both studies, detection of anti-ANG IgA in sera by ELISA. JPI was defined as acute clinical sings of infection during the first 3 months after the placement of the prosthesis. Serum samples were obtained from 500 healthy adults. IgA antibodies, reacting with ANG tested, were present in the sera of all patients as well as in the sera of normal individuals. Serum levels of anti-ANG IgA are significantly low in 19.1% patients with pre-surgical total joint replacement than in healthy individuals (m±SD: 385±101 versus 121±98; P< 0.001). Very low serum levels of anti-ANG IgA, as occur in primary immunodeficiency syndromes, are associated with significantly increased risk of infections (r=0.85; P< 0.005). Increases in serum anti-ANG IgA to normal/higher levels in patients before surgery associated with good response after gammaglobulin replacement therapy (m±SD: 385±101 versus 587±189; P< 0.001).Risk of JPI was dependently associated with secretory anti-ANG IgA antibody responses. Very low the expression of anti-ANG IgA in sera seem to be potentially useful as angiogenic biomarkers of risk JPI

In 2011, approximately 1.6 million total hip arthroplasties (THAs) were conducted in 27 of the 34 member countries in the Organization for Economic Cooperation and Development (OECD) However, approximately 10–15% of patients still require revision surgery every year. Therefore, new technologies are required to increase the life-spam of the prosthesis from the current 10–15 years to at least 20–30 years. Our strategy focuses on surface modification of the bearing materials with a hydrophilic coating to improve their wear behaviour. These coatings are biocompatible, with high swelling capacity and antifouling properties, mimicking the properties of natural cartilage, i.e. wear resistance with permanent hydrated layer that prevents prosthesis damage. Clear beneficial advantages of this coating have been demonstrated in different conditions and different materials, such as UHMWPE, PEEK, CrCo, Stainless steel, ZTA and Alumina. Using routine tribological experiments, the wear for UHMWPE substrate was decreased by 75% against alumina, ZTA and stainless steel. For PEEK-CFR substrate coated, the amount of material lost against ZTA and CrCo was at least 40% lower. Further experiments on hip simulator adding abrasive particles (1-micron sized aluminium particles) during 3 million cycles, on a total of 6 million, showed a wear decreased of around 55% compared to uncoated UHMWPE and XLPE. In conclusion, CIDETEC‘s coating technology is versatile and can be adapted to protect and improve the tribological properties of different types of surfaces used for prosthesis, even in abrasive conditions.

Introduction

Modularity allows surgeons to use femoral heads of various materials, diameters and offsets to achieve the best possible outcome, nevertheless the fretting corrosion behaviour of modular junctions can be significantly affected. The aim of this study was to assess physiological friction moment and lubrication ratio in order to compare various tribological materials against different bearing sizes. This data is important as lubrication will affect the friction, wear and torque generated which may lead directly to the production of debris or to enhanced corrosion at modular junctions.

It is widely accepted that a wide contact area between bone and artificial materials is necessary in the fixation of hip joint prostheses. It is also considered be applied to the proximal femur. However, these two concepts are contradictory in that the contact point cannot be determined in a wide contact area. Therefore, in this study, we revised the available concepts to improve the method of fixation of joint prostheses using finite-element-method (FEM) analysis of the equivalent mathematical models.

The first model was designed based on the intramedullary cruciate fixation stem. In this model, the total contact area was limited to the small area of legs-on-plane. Another model was designed based on the fit-and-fill-type stem, and in this model, the total contact area of the plane-on-plane was equal to the total surface area of the stem. In the plane-on-plane model, there was an unstable vibrating pattern in stress distribution, and we considered that deterministic chaos existed in the stress filled wide

It is widely accepted that a wide contact area between bone and artificial materials is necessary in the fixation of hip joint prostheses. It is also considered important that the load should be applied to the proximal femur. However, these two concepts are contradictory in that the contact point cannot be determined in a wide contact area. Therefore, in this study, we revised the available concepts to improve the method of fixation of joint prostheses using finite-element-method (FEM) analysis of the equivalent mathematical models. The first model was designed based on the intramedullary cruciate fixation stem. In this model, the total contact area was limited to the small area of legs-on-plane. Another model was designed based on the fit-and-fill-type stem, and in this model, the total contact area of the plane-on-plane was equal to the total surface area of the stem. In the plane-on-plane model, there was an unstable vibrating pattern in stress distribution, and we considered that deterministic cha

The employment of biophysical therapy to accelerate the healing of tissues is by now a well-established practice in many orthopaedic situations, indicated mainly for osteogenesis and chondrogenesis. Assessments of the effects of biophysical stimuli on joint cartilage (CRES, Cartilage Repair & Elecromagnetic Stimulation) performed with pre-clinical studies and clinical studies (in operations to reconstruct LCA and microfractures) have shown how biophysical stimulation controls the microambience, and have suuplied the rationale for passing to an evaluation of the effects also in the case of joint replacement.

We launched a randomized prospective clinical study of 30 patients aged between 60 and 85 years, afflicted with gonarthrosis and undergoing operation for prosthesis. The randomization involved subdividing them into two homogeneous groups: the first with biophysical treatment with I-ONE therapy (Igea-Clinical Biophysics) (experimental group); the second not undergoing the biophysical treatment (control group). In the experimenal group, the I-ONE therapy was commenced at 3–7 days from the operation, administered for 4 hours per day and maintained for 60 days consecutively. The clinical evaluations were performed by compiling functional reports (swelling of the knee, Knee Score, SF-36 and VAS) in the pre-operative period and postoperatively at 1, 2, 6 and 12 months. The data processing was subjected to statistical evaluation by an independent observer using Student’s two-tail t test and the Generalized Linear Mixed Effects Model.

The preliminary results showed that at the baseline there are no differences between the groups either for the KNEE score, nor the VAS, or the SF-36. Already after 1 month the differences between the groups are statistically significant (p< 0.05 for KNEE score, p< 0.001 for swelling, p< 0.0001 for VAS and SF-36). At 2 months the differences between the groups are highly significant (p< 0.0001). The study entails a long-term evaluation with monitoring of the patients at one year from operation.

The results of this study supply the basis for clinical employment of biophysical treatment with I-ONE immediately following joint surgery, enabling inflammation to be controlled and increasing anabolic activity and protecting its microambience.

Purpose: The ABG Total Hip Joint Replacement is a cementless, hydroxyapatite coated prosthesis designed to be metaphyseal loading. The aim of our study was to analyze the changes in proximal femoral bone mineral density (BMD) following implantation of this prosthesis.

Method: Dual energy x-ray absorptiometry (DEXA) scanning has been shown to be an accurate and reliable method of assessing BMD following total hip arthroplasty. 14 patients undergoing primary ABG Total Hip Joint Replacement were recruited into the study following informed consent. BMD was determined for each of the seven periprosthetic zones of Gruen from DEXA scans, which were performed serially at preoperative,, 3 months, 6 months, 1 year and 2 years.

Results: 8 patients have now completed their scans. The most dramatic change in BMD was found in zone 7 which is the femoral calcar. In this region there was a progressive decrease in average BMD to 75% of the preoperative value at 2 years. In zones 2 and 3 representing the femoral cortex lateral to the prosthesis there was an increase in BMD to approximately 114.5% at 3 months and this was maintained at 2 years. In the remaining zones BMD was reasonably stable between 97.5 and 101%.

Conclusion: We have found that in the 2 years following ABG hip arthroplasty there is a dramatic decrease in BMD to 75% within the region of the femoral calcar. Further scans are required to determine if this is progressive. In the remaining regions BMD is either increased or relatively well preserved.

Aim. To develop a new system for antibacterial coating of joint prosthesis and osteosynthesis material. The new coating system was designed to release gentamicin immediately after insertion to eradicate surgical contamination. Method. Steel implants (2×15mm) were coated with a solid nanocomposite xerogel made from silica and the dendritic polymer, hyperbranched polyethyleneimine. The xerogel was anchored inside a porous surface made by pre-coating with titanium microspheres. Finally, gentamicin was encapsulated in the xerogel, i.e. no chemical binding. A total of 50 µg gentamicin was captured into each implant. The efficacy of the new coating was evaluated in a porcine model of implant associated osteomyelitis. In total, 30 female pigs were randomized into 3 study groups (n=10). Group A; plain implants + saline, Group B; plain implants + 10. 4. CFU of Staphylococcus aureus, and Group C; coated implants + 10. 4. CFU of S. aureus. Implant + inoculum was placed into a pre-drilled implant cavity of the right tibia and the pig was euthanized 5 days afterwards. Postmortem microbiology and pathology were performed. Two additional pigs were used in a pharmacokinetic study where microdialysis (MD) catheters were placed alongside coated implants. Extracellular fluid was sampled regularly for 24 hours from the MD catheters and analyzed for gentamicin content. Results. Within Groups A and C, all implants were found sterile by sonication and bacteria could not be identified within the surrounding bone tissue. In contrast, all Group B animals had S. aureus positive implant and tissue microbiology. Macroscopic and microscopic pathological examinations confirmed that Group A and C animals were complete identic, i.e. no pus around implants and only minor peri-implant inflammation related to insertion of implants per se. All Group B animals had pus around their implants and a massive peri-implant inflammatory response dominated by neutrophil granulocytes. Maximum gentamicin release (35 µg /mL) was measured in the first obtained MD sample, i.e. after 30 min, and the concentration stayed above the MIC level for the used S. aureus strain for 8 hours. Conclusions. The new xerogel coating prevented development of osteomyelitis. Prevention was due to a fast gentamicin release immediately following insertion and antimicrobial active concentrations were detectable several hours after implantation. This means that the critical time point of most relevant surgical procedures potentially could be protected by the novel coating. The new coating will be investigated on larger scale implants and full-size prosthesis in the future

Aim. The risk of haematogenic periprosthetic joint infection (PJI) after dental procedures is discussed controversially. To our knowledge, no study has evaluated infections according to the origin of infection based on the natural habitat of the bacteria. We investigated the frequency of positive monomicrobial cultures involving bacteria from oral cavity in patients with suspected PJI compared to bone and joint infections without joint prosthesis. Method. In this retrospective study we included all patients with suspected PJI or bone and joint infection without endoprosthesis, hospitalized at our orthopaedic clinic from January 2009 through March 2014. Excluded were patients with superficial surgical site infections or missing data. Demographic, clinical and microbiological data were collected using a standardized case report form. Groups were compared regarding infections caused by oral bacteria. χ2 test or Fisher's exact test was employed for categorical variables and t-test for continuous variables. Results. A total of 1673 patients were included, of whom 996 (60%) had a suspected PJI and 677 (40%) an osteoarticular infection without joint endoprosthesis (control group). In patients with suspected PJI the median age (standard deviation) was 67 (14) years; 407 (41%) were males. The anatomic location of the prosthesis was hip in 522 (52%) patients, knee in 437 (44%), megaprostheses in 14 (1%), shoulder in 8 (1%) and other endoprosthesis in 15 (2%) patients. In 437 (44%) of PJI cases pathogen(s) were detected, 271 (62%) were monomicrobial and 166 (38%) polymicrobial. Of 996 patients with suspected PJI, 2.4% (n = 24) had monomicrobial infections caused by bacteria belonging to the normal oral flora, predominantly oral streptococci (n = 21). In contrast, only 0.4% (n =3) of the control group without joint prosthesis had monomicrobial infections caused by oral bacteria. This difference was statistically significant (p = 0.002), whereas the patient age (p = 0.058) and the anatomic location of the joint prosthesis (p = 0.622) did not have any effect on the infections due to oral bacteria. Conclusions. The incidence of infections caused by oral bacteria was significantly higher in patients with endoprosthesis than in other osteoarticular infections (2.4% versus 0.4%). This finding indicates that joint prostheses are at risk of haematogenous PJI originating from oral cavity. Future prospective studies need to determine the exact risk of haematogenic PJI caused by oral bacteria, as well as the potential of preventing these infections by antibiotic prophylaxis

Aims

Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism.

Aims

The primary aim of this prospective, multicentre study is to describe the rates of returning to golf following hip, knee, ankle, and shoulder arthroplasty in an active golfing population. Secondary aims will include determining the timing of return to golf, changes in ability, handicap, and mobility, and assessing joint-specific and health-related outcomes following surgery.

Aims

This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation.

Total hip arthroplasty (THA) is one of the most successful and effective treatments for advanced hip osteoarthritis (OA). Over the last 5 years, Canada has seen a 17.8% increase in the number of hip replacements performed annually, and that number is expected to grow along with the aging Canadian population. However, the rise in THA surgery is associated with an increased number of patients at risk for the development of an infection involving the joint prosthesis and adjacent deep tissue – periprosthetic joint infections (PJI). Despite improved hygiene protocols and novel surgical strategies, PJI remains a serious complication. No previous population-based studies has investigated PJI risk factors using a time-to-event approach and none have focused exclusively on patients undergoing THA for primary hip OA. The purpose of this study is to determine risk factors for PJI after primary THA for OA using a large population-based database collected over 15 years. Our secondary objective is to determine the incidence of PJI, the time to PJI following primary THA, and if PJI rates have changed in the past 15 years. We performed a population-based cohort study using linked administrative databases in Ontario, Canada in accordance with RECORD and STROBE guidelines. All primary total hip replacements performed for osteoarthritis in patients aged 55 or older between January 1st 2002 – December 31st 2016 in Ontario, Canada were identified. Periprosthetic joint infection as the cause for revision surgery was identified with the International Classification of Diseases, 10th Edition (ICD-10), Clinical Modification diagnosis code T84.53 in any component of the healthcare data set. Data were obtained from the Institute for Clinical Evaluative Sciences (ICES). Demographic data and outcomes are summarized using descriptive statistics. We used a Cox proportional hazards model to analyze the effect of surgical factors and patient factors on the risk of developing PJI. Surgical factors include the approach, use of bone graft, use of cement, and the year of surgery. Patient factors include sex, age at surgery, income quintile and rurality (community vs. urban). We compared the 1,2,5 and 10 year PJI rates for patients undergoing THA each year of our cohort with the Cochran-Armitage test. Less than 0.1% of data were missing from all fields except for rurality which was lacking 0.3% of data. A total of 100,674 patients aged 55 or older received a primary total hip arthroplasty for osteoarthritis from 2002–2016. We identified 1034 cases of revision surgery for prosthetic joint infection for an overall PJI rate of 1.03%. When accounting for patients censored at final follow-up, the cumulative incidence for PJI is 1.44%. Our Cox proportional hazards model revealed that male sex, Type II diabetes mellitus, discharge to convalescent care, and having both hips replaced during one's lifetime were associated with increased risk of developing PJI following primary THA. Importantly, the time adjusted risk for PJI was equal for patients operated within the past 5 years, 6–10 years ago, or 11–15 years ago. The surgical approach, use of bone grafting or cement were not associated with increased risk of infection. PJI rates have not changed significantly over the past 15 years. One, two, five and ten-year PJI rates were similar for patients undergoing THA in all qualifying years. Analysis of a population-based cohort of 100,674 patients has shown that the risk of developing PJI following primary THA has not changed over 15 years. The surgical approach, use of bone grafting or cement were not associated with increased risk of infection. Male sex, Type II diabetes Mellitus and discharge to a rehab facility are associated with increased risk of PJI. As the risk of PJI has not changed in 15 years, an appropriately powered trial is warranted to determine interventions that can improve infection rate after THA

Aims

Although low-intensity pulsed ultrasound (LIPUS) combined with disinfectants has been shown to effectively eliminate portions of biofilm in vitro, its efficacy in vivo remains uncertain. Our objective was to assess the antibiofilm potential and safety of LIPUS combined with 0.35% povidone-iodine (PI) in a rat debridement, antibiotics, and implant retention (DAIR) model of periprosthetic joint infection (PJI).

Introduction. We have developed a new synthetic hydrogel that can be injected directly into the intervertebral disc (IVD) without major surgery. Designed to improve fixation of joint prosthesis, support bone healing or improve spinal fusion, the liquid may support the differentiation of native IVD cells towards osteoblast-like cells cultured within the hydrogel. Here we investigate the potential of this gel system (Bgel) to induce bone formation within intervertebral disc tissue. Methods. IVD tissue obtained from patients undergoing discectomy, or cadaveric samples, were cultured within a novel explant device. The hydrogel was injected, with and without mesenchymal stem cells (MSCs), and cultured under hypoxia, to mimic the degenerate IVD environment, for 4 weeks. Explants were embedded to wax and native cellular migration into the hydrogel was investigated, together with cellular phenotype and matrix deposition. Results. Increased collagen deposition was seen in tissue explants injected with Bgel, with evidence of elevated native cell migration towards the hydrogel. Increased collagen staining was seen in explants injected with Bgel together with MSCs. Alizarin red staining was utilised to investigate calcium deposition. Tissue explants, in the absence of Bgel, showed limited calcium deposition. This was increased in hydrogel-treated samples, with large clumping regions in the tissue that was injected with Bgel and MSCs. Conclusion. The injection of our synthetic hydrogel into disc tissue explants increased the amount of collagen and calcium deposition. This was further enhanced by the incorporation of MSCs, suggesting the promotion of bone formation. Current work is investigating phenotypic markers for bone formation within these tissues. CS and CLM have a patent on the hydrogel system described in this abstract. Funded by EPSRC and Grow MedTech

Aim. Periprosthetic joint infections (PJI) are increasing due to our elderly population with the need of a joint prosthesis. These infections are difficult to treat, because bacteria form biofilms within one day on the orthopedic implant surface. Notably, most of the current available antibiotics do not penetrate the biofilm or are not active against the sessile forms of bacteria. Therefore, prevention is key. In the current paradigm, bacteria from the skin surface or dermis - such as Staphylococcus aureus, coagulase-negative staphylococci, or Cutibacterium sp. – contaminate the periimplant tissue during surgery. Cutibacterium avidum, which has increasingly been reported in hip PJIs, colonizes the skin in the groin area in 32.3%. We were wondering if standard skin antisepsis before hip arthroplasty is effective to eliminate C. avidum colonization in the surgical field. Method. In a single-center, prospective study, we preoperatively screened all patients undergoing a hip arthroplasty through a direct anterior approach for different skin bacteria in the groin area. Only in patients colonized with C. avidum, we intraoperatively searched for persistent bacterial growth during and after triple skin antisepsis with povidone-iodine/alcohol. For that, we collected skin scrapings after first and third antisepsis and biopsies from the dermis at the surgical incision and evaluated bacterial growth and species. In addition, thin sections of the dermis biopsies were submitted to Fluorescence in situ Hybridization (FISH) using pan-bacteria probe EUB338. Results. From October 2018 until March 2019, 53 patients (47.2% female) were screened. Patients were mainly colonized with coagulase-negative staphylococci (41, 77.4%; 41), C. avidum (12, 22.6%), and Cutibacterium acnes (8, 15.1%). Intraoperative skin antisepsis of patients colonized with C. avidum was ineffective to eliminate any bacteria in 75% (5 out of 7) after the first and 28.6% (2 out of 7) after the third antisepsis. Focusing on C. avidum, antisepsis was ineffective in 43% (3 out of 7) and 14% (1 out of 7), respectively. Dermis biopsies were all culture negative, but FISH showed positive ribosome-rich bacteria in 50%. Conclusions. We show in our ongoing study that the commensal C. avidum resists the standard skin antisepsis and bacteria visually persist in the dermis as demonstrated by FISH technique. Standard skin antisepsis is of limited effectiveness, resulting in a risk for intraoperatively acquired PJIs. Thus, new and more effective techniques to improve skin antisepsis are urgently needed

Aim. A previous Dutch guideline for prophylaxis of hematogenous PJI (HPJI) caused defensive medicine and incorrect own guidelines. There was a need for a better national guideline, developed cooperatively by orthopedic surgeons and dentist. Method. A committee of Dutch Orthopedic and Dental Society, performed a systematic literature review to answer the question: “Is there a difference in the risk for hematogenous infection between always or never giving antibiotic prophylaxis to patients with a joint prosthesis undergoing a dental procedure”. We included 9 papers as follows:. 1. RCT's and systematic reviews: 539 abstracts > 33 full papers > 1 paper included. 2. observational studies: 289 abstracts > 12 full papers > 5 papers. 3. reference-to-reference: 3 papers. The nine papers’ quality was scored according the GRADE method. In addition we studied in non-included literature on further information about additional questions of pathophysiology, risk factors and risk procedures. Results. No evidence was found that prophylactic antibiotics have an effect on the incidence of HPJI (Grade score: very low). We concluded from the non-included literature that:. 1. Bacteremia in dental procedures is frequent, but even more frequent in daily life. The influence of antibiotics on bacteremia is uncertain. 2. There is no evidence that in the first 2 years after implantation the risk for HPJI is increased. 3. There is no evidence that “bleeding” during dental procedures is associated with more bacteremia. 4. The relation between decreased immune status and the risk for HPJI is unclear. Also in these patients the cumulative dose of bacteremia is much higher in daily life as compared with dental procedures. 5. A risk/benefit analysis could not be made, since the data are too uncertain of effectivety of antibiotics, incidence of HPJI and of side effects of antibiotics. 6. For the same reason a cost/effectivety analysis was not possible. Even reliable data are missing about the prevalence of joint prosthesis patients. 7. There are increasing data about the relation between the oral and general health. Therefore good oral hygiene and regular dental controls is advised. 8. We could not conclude if the prophylactic use of oral Chlorhexidine prior to a dental procedure has any positive influence on HPJI incidence. Conclusions. the guideline states:. 1. there is no indication for antibiotic prophylaxis in dental procedures. 2. also not in case of decreased immunity. 3. patients should be advised to maintain good oral hygiene and have regular dental control

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.