Aim. Prosthetic joint infection (PJI) presents the second most common complication of total joint arthroplasty (TJA). Accumulating evidence suggests that up to 20% of aseptic failures are low-grade PJI. However, there is still no single test to reliably diagnose all PJI. In his thesis, Mazzucco emphasized the viscosity differences between normal, osteoarthritic, and rheumatic synovial fluid. Similarly, a recent study by Fu et al. reported significantly lower viscosity in patients with PJI compared to the aseptic failure cohort. The primary aim of our study was to determine whether synovial fluid viscosity is a more reliable diagnostic criterion for PJI compared to the synovial fluid cell count with differential and serum C-reactive protein (CRP) levels. Method. We prospectively analyzed the viscosity of synovial fluid samples obtained during TJA of hip and knee joint revision procedures. We sampled 2.5–5 mL of synovial fluid for viscosity measurement. The samples were centrifuged (4 min at 7000 rpm) and the resulting supernatant was immediately transferred into the Ostwald viscometer. Viscosity was derived from the time required for a given volume of synovial fluid to pass the viscometer at 20 °C. The synovial fluid samples were also analysed for their cell count with differential and serum CRP was measured. The definite diagnosis of PJI was established on basis of EBJIS criteria. For the viscosity, the threshold for detecting PJI was set at 65 seconds. Results. Between December 2020 and March 2021, we analyzed 12 knee and 11 hip TJA revision samples. These included 14 septic and 9 aseptic synovial fluid samples. The average viscometer time in the PJI group was 31s (range 20–48s) compared to 247s (range 68–616s) in the group of aseptic revision procedures. The specificity and sensitivity of our viscosity measurements were 100%. The sensitivity and specificity of cell count was 100% and 85.7%, for the synovial fluid differential they were 100% and 85.7%, and for the CRP they were 88.9% and 71.4%, respectively. Conclusions. Our study is the first to report a significant difference in synovial fluid viscosity between the PJI and the aseptic cohort. It points towards the diagnostic superiority of viscosity measurements over conventional synovial fluid cell count, synovial fluid differential, and serum CRP levels. Albeit currently limited by small sample size, the study remains ongoing

The inmate population is a unique cohort with several healthcare-related challenges. International studies have demonstrated higher rates of infectious diseases, chronic diseases and psychiatric disorders in inmates when compared to general population. However, little is known about the outcomes following total joint arthroplasty in this population. This retrospective chart review aims to outline the differences in clinical outcomes after hip and knee total joint arthroplasty in the Kingston inmate population compared to the national population standard. A list of all inmate inpatient hospital visits with diagnostic/procedure codes pertaining to total joint arthroplasty within the last ten years was obtained through a computer-based search of the Kingston General Hospital Discharge Abstract Database(DAD). The patient charts were reviewed and demographic and outcome data pertinent to our study was collected. Data was compiled using Excel and imported into IBM SPSS for descriptive analysis. Twenty male inmate patients underwent 24 primary Total Hip Arthroplasties(THA) or Total Knee Arthroplasties(TKA) and one medial unicompartmental knee arthroplasty from May 2003 to January 2013. The average age was 58 with mean Body Mass Index(BMI) of 34. Median American Society of Anesthesiologist(ASA) score was 3 and mean Charlston Comorbidity Index was 3.92. The rates of HCV and HIV were 35%(n=5) and 0%, respectively. Average length of stay from time of initial procedure was 4.2 days. The overall revision rate was 24% (n=6). Reasons for revision included deep prosthetic infection (50%, n=3), aseptic loosening (17%, n=1), arthrofibrosis (17%, n=1) and late periprosthetic fracture (17%, n=1). Infection rates were reported at 16% (n=4); 75% of which were deep prosthetic infections requiring revision surgery. Other complications included ST-elevation myocardial infarction(STEMI) (n=1), and postoperative knee stiffness requiring manipulation under anesthesia(MUA) (n=1). Compared to Correctional Services Canada(CSC) data on male inmate health in 2012, our study population demonstrated a higher rate of HCV (35% vs. 9.4%), diabetes (30% vs. 4.2%) and overall cardiovascular and respiratory comorbidities. This may reflect the higher rate of comorbidities associated with osteoarthritis, such as BMI>25, which was evident in 95% of our study population vs. 64.5% in Canadian inmates. Total joint revision rates in our inmate study population was 24%, which is higher than the 2014 Canadian Joint Replacement Registry's yearly revision rate of 8.7% in THA and 5.2% in TKA. Our study population also demonstrated infection as the leading cause for revision at 50%, compared to 14.5% for THA and 19.6% for TKA in the general Canadian population. Further study of the complex biopsychosocial risk factors in the inmate population is warranted to better define pre-surgical risk assessment criteria

Periprosthetic joint infections are one of the most dreaded and complex complications of total joint arthroplasty, with fungal infection accountting for less than 1% of the cases. Treatment is challenging due to the lack of scientific evidence. We report a case of a Candida albicans total hip arthroplasty (THA) infection and performed a review of the literature. We report a case of a 79 year old women with an early THA infection (less of one month) from the primary surgery. She presented with pain and serous drainage from the operative wound and for that was submited to surgical debridement and revision of polyethilene. Cultures where taken (steril) and empirical vancomicin and rifampicin treatment was initiated. Because of persistent complains and drainage, the patient was submitted to another surgery. Cultures were taken at the time of surgery. A cement spacer impregnated with gentamicin was placed after implant removal. Cultures isolated Candida albicans. In light of this new evidence fluconazole was added to the previous scheme. After introduction of fluconazole, the clinical evolution was good. Drainage stoped 1 week after, and the wound closed. The inflammatory markers became normal shortly after. Leg pain became better. The patient was given oral suppressive treatment with fluconazole and was discharged, weight bearing as tolerated. A total of 4 mouths of treatment is programmed with close follow-up, untill the second staged revision is programmed. Prosthetic fungal infections are rare with most of the published articles being case reports. A substantial delay in diagnosis may occur because culture results are sometimes interpreted as contamination and there is a need for obtaining multiple samples, prolonged culture, and special staining. The best results are being reported with a long period of oral antifungal treatment and a two staged joint revision but there is an absence of standardized clinical and evidence-based treatment guidelines

Prosthetic joint infections (PJI) caused by Streptococcus species are relatively common. The aim of our study was to assess outcome after treatment for early and late PJI with Streptococcus species after a follow-up of two years. For this study we retrospectively included all patients with primary or revision total knee arthroplasty (TKA) or total hip (THA) arthroplasty, a minimum of two periprosthetic tissue cultures positive for Streptococcus species and a minimum follow-up of one year. According to international guidelines patients were classified as having early or late PJI. All patients with an early PJI were treated according to a standard treatment protocol, i.e. debridement and retention of the prosthesis, followed by adequate antibiotic therapy. Patients with late PJI underwent a debridement followed by adequate antibiotic therapy or joint revision. Patients’ hospital records were reviewed and we evaluated the status of the original prosthesis after an infection. Forty cases were included; 24 early and 16 late PJI. For early PJI, open debridement was performed in all patients, after a mean of 19 (range: 9 – 80) days. At final follow-up 21 prostheses (88%) were still in situ and without clinical signs of infection. Eight cases (41%) of late PJI were successfully treated with debridement and retention. Nine patients (59%) underwent a one- or two-stage revision. At final follow-up 16 patients (100%) with late PJI had a prosthesis in situ. Streptococcus dysgalactiae species accounted for more than 50% of the early infections, followed by Streptococcus agalactiae with 30%. In case of PJI with Streptococcus species open debridement and retention of the prosthesis should be performed followed by adequate and long-term antibiotic treatment. As expected, the retention rate for early PJI is much higher than that for late PJI

The use of new megaprosthesis for massive bone loss is an option for the replacement of skeletal segments. There are several clinical scenarios that can be associated with this situation including severe trauma with multiple failed osteosynthesis with a non union or with a previous prosthetic replacement of a neighbouring joint; multiple revision of arthroplasty with or without infections or large resections of tumours. The aim of this work is to evaluate retrospectively both clinical and radiological outcomes and any complications in patients treated with megaprosthesis in SEPTIC BONE DEFECTS in our Hospital from February 2012 to January 2015. From February 2012 to January 2014 a total of 20 patients were treated with mono-and bi-articular megaprosthesis subdivided as follows: 4 proximal femur, 11 distal femur, 3 total femur, 1 total humerus and 1 proximal humerus. Clinical and serial radiographic evaluations were performed at 6 weeks, 3, 6, 12, 18 and 24 months. Blood parameters with CRP and ESR were monitored for at least 2 months. The mean follow-up of patients was about 24.4 months (range 5 months to 31 months). The mean age of the patients was 53 years (range 37–80years). Of the patients 20, 9 were female and 11 were male. The aetiology was: 11 septic non unions, 3 infected TKA, 4 infected THR and 2 infected tumor prostheses. We have evaluated retrospectively both clinical and radiological outcomes of 20 patients. They had large bone defects that threatened the viability of the limb. They were treated with megaprosthesis. Although the mean length of follow-up was only 24.4 months they showed encouraging clinical results, with good articulation of the segments, no somato-sensory or motor deficit and acceptable functional recovery. There were three cases of dislocation, one case with rifampicin toxicity, one case with acute prosthetic infection (case that needed debridement and one case with chronic oral antimicrobial. Megaprosthesis provides a valuable opportunity to restore functionality to patients with highly disabling diseases. The number of complications is not depreciable

The number of joint revision surgeries is rising, and the complexity of the cases is increasing. In 58% of the revision cases, the acetabular component has to be revised. For these indications, literature decision schemes [Paprosky 2005] point at custom pre-shaped implants. Any standard device would prove either unfeasible during surgery or inadequate in the short term. Studies show that custom-made triflanged implants can be a durable solution with good clinical results. However, the number of cases reported is few confirming that the device is not in widespread use. Case Report. A patient, female 50 yrs old, diagnosed having a pseudotumor after Resurfacing Arthroplasty for osteo-arthritis of the left hip joint. The revision also failed after 1 y and she developed a pelvic discontinuity. X-ray and Ct scans were taken and sent to a specialized implant manufacturer [Mobelife, Leuven, Belgium]. The novel process of patient-specific implant design comprises three highly automated steps. In the first step, advanced 3D image processing presented the bony structures and implant components. Analysis showed that anterior column was missing, while the posterior column was degraded and fractured. The acetabular defect was diagnosed being Paprosky 3B. The former acetabular component migrated in posterolateral direction resulting in luxation of the joint. The reconstruction proposal showed the missing bone stock and anatomical joint location. In the second step, a triflanged custom acetabular metal backing implant was proposed. The bone defect (35ml) is filled with a patient-specific porous structure which is rigidly connected to a solid patient-specific plate. The proposed implant shape is determined taking into account surgical window and surrounding soft tissues. Cup orientation is anatomically analyzed for inclination and anteversion. A cemented liner fixation was preferred (Biomet Advantage 48mm). Screw positions and lengths are pre-operatively planned depending on bone quality, and transferred into surgery using jig guiding technology (Materialise NV, Leuven, Belgium). In the third step, the implant design was evaluated in a fully patient-specific manner in dedicated engineering (FEA) software. Using the novel automated CT-based methodology, patient-specific bone quality and thickness, as well as individualised muscle attachments and muscle and joint forces were included in the evaluation. Implants and jig were produced with Additive Manufacturing techniques under ISO 13485 certification, using respectively Selective Laser Melting (SLM) techniques [Kruth 2005] in medical grade Ti6Al4V material, and the Selective Laser Sintering technique using medical grade epoxy monomer. The parts were cleaned ultrasonically, and quality control was performed by optical scanning [Atos2 scanning device, GOM Intl. AG, Wilden, Switzerland]. Sterilization is performed in the hospital. CONCLUSION. A unique combination of advanced 3D planning, patient-specific designed and evaluated implants and drill guides is presented. This paper illustrates, by means of a clinical case, the novel tools and devices that are able to turn reconstruction of complex acetabular deficiencies into a reliable procedure

Professor Mario Mercuri passed away suddenly after a complication of cancer on 7th May 2011 after dedicating his entire life to patients with tumours.

The Department of Health and the Public Health Laboratory Service established the Nosocomial Infection National Surveillance Scheme in order to standardise the collection of information about infections acquired in hospital in the United Kingdom and provide national data with which hospitals could measure their own performance. The definition of superficial incisional infection (skin and subcutaneous tissue), set by the Center for Disease Control (CDC), should meet at least one of the defined criteria which would confirm the diagnosis and determine the need for specific treatment.

We have assessed the interobserver reliability of the criteria for superficial incisional infection set by the CDC in our current practice. The incisional site of 50 patients who had an elective primary arthroplasty of the hip or knee was evaluated independently by two orthopaedic clinical research fellows and two orthopaedic ward sisters for the presence or absence of surgical-site infection. Interobserver reliability was assessed by comparison of the criteria for wound infection used by the four observers using kappa reliability coefficients. Our study demonstrated that some of the components of the current CDC criteria were unreliable and we recommend their revision.