Aims

The surgical helmet system (SHS) was developed to reduce the risk of periprosthetic joint infection (PJI), but the evidence is contradictory, with some studies suggesting an increased risk of PJI due to potential leakage through the glove-gown interface (GGI) caused by its positive pressure. We assumed that SHS and glove exchange had an impact on the leakage via GGI.

Aims. This study aimed to investigate the estimated change in primary and revision arthroplasty rate in the Netherlands and Denmark for hips, knees, and shoulders during the COVID-19 pandemic in 2020 (COVID-period). Additional points of focus included the comparison of patient characteristics and hospital type (2019 vs COVID-period), and the estimated loss of quality-adjusted life years (QALYs) and impact on waiting lists. Methods. All hip, knee, and shoulder arthroplasties (2014 to 2020) from the Dutch Arthroplasty Register, and hip and knee arthroplasties from the Danish Hip and Knee Arthroplasty Registries, were included. The expected number of arthroplasties per month in 2020 was estimated using Poisson regression, taking into account changes in age and sex distribution of the general Dutch/Danish population over time, calculating observed/expected (O/E) ratios. Country-specific proportions of patient characteristics and hospital type were calculated per indication category (osteoarthritis/other elective/acute). Waiting list outcomes including QALYs were estimated by modelling virtual waiting lists including 0%, 5% and 10% extra capacity. Results. During COVID-period, fewer arthroplasties were performed than expected (Netherlands: 20%; Denmark: 5%), with the lowest O/E in April. In the Netherlands, more acute indications were prioritized, resulting in more American Society of Anesthesiologists grade III to IV patients receiving surgery. In both countries, no other patient prioritization was present. Relatively more arthroplasties were performed in private hospitals. There were no clinically relevant differences in revision arthroplasties between pre-COVID and COVID-period. Estimated total health loss depending on extra capacity ranged from: 19,800 to 29,400 QALYs (Netherlands): 1,700 to 2,400 QALYs (Denmark). With no extra capacity it will take > 30 years to deplete the waiting lists. Conclusion. The COVID-19 pandemic had an enormous negative effect on arthroplasty rates, but more in the Netherlands than Denmark. In the Netherlands, hip and shoulder patients with acute indications were prioritized. Private hospitals filled in part of the capacity gap. QALY loss due to postponed arthroplasty surgeries is considerable. Cite this article: Bone Jt Open 2022;3(12):977–990

Extended patient waiting lists for assessment and treatment are widely reported for planned elective joint replacement surgery. The development of regionally based Elective Orthopaedic Centres, separate from units that provide acute, urgent or trauma care has been suggested as one solution to provide protected capacity and patient pathways. These centres will adopt protocolised care to allow high volume activity and increased day-case care. We report the plan to establish a new elective orthopaedic centre serving a population of 2.4 million people. A census conducted in 2022 identified that 15000 patients were awaiting joint replacement surgery with predictions for further increases in waiting times. The principle of care will be to offer routine primary arthroplasty surgery for low risk (ASA 1 and 2) patients at a new regional centre. Pre-operative assessment and preparation will be undertaken digitally, virtually and/or in person at local centres close to the where patients live. This requires new and integrated pathways and ways of working. Predicting which patients will require perioperative transfusion of blood products is an important safety and quality consideration for new pathways. We reviewed all cases of hip and knee arthroplasty surgery conducted at our centre over a 12-month period and identified pre-operative patient related predictive factors to allow us to predict the need for the perioperative transfusion of blood products. We examined patient sex, age, pre-operative haemaglobin and platelet count, use of anti-coagulants, weight and body mass index to allow us to construct the Imperial blood transfusion tool. We have used the results of our study and the transfusion tool to propose the patient pathway for the new regional elective orthopaedic centre which we present

There is an increasing incidence of revision for periprosthetic joint infection. The addition of vancomycin to beta-lactam antimicrobial prophylaxis in joint arthroplasty may reduce surgical site infections, however, the efficacy and safety have not been established. This was a multicenter, double-blind, superiority, placebo-controlled trial. We randomized 4239 adult patients undergoing joint arthroplasty surgery to receive 1.5g vancomycin or normal saline placebo, in addition to standard cefazolin antimicrobial prophylaxis. The primary outcome was surgical site infection at 90-days from index surgery. Perioperative carriage of Staphylococcus species was also assessed. In the 4113 patients included in the modified intention-to-treat population, surgical site infections occurred in 72/2069 (3.5%) in the placebo group and 91/2044 (4. 5%) in the vancomycin group (risk ratio 1.28; 95% confidence interval 0.94 to 1.73; p value 0.11). No difference was observed between the two groups for primary hip arthroplasty procedures. A higher proportion of infections occurred in knee arthroplasty patients in the vancomycin group (63/1109 [4.7%]) compared with the placebo group (42/1124 [3.7%]; risk ratio 1.52; 95% confidence interval 1.04 to 2.23; p value 0.031). Hypersensitivity reactions occurred in 11 (0.5%) patients in the placebo group and 24 (1.2%) in the vancomycin group (risk ratio 2.20; 95% confidence interval 1.08, 4.49) and acute kidney injury in 74 (3.7%) patients in the placebo group and 42 (2.1%) in the vancomycin group (risk ratio 0.57; 95% confidence interval 0.39, 0.83). Perioperative Staphylococcus aureus carriage was detected in 1089/3748 (29.1%) of patients. This is the first randomized controlled trial examining the addition of a glycopeptide antimicrobial to standard beta-lactam surgical antimicrobial prophylaxis in joint arthroplasty. The addition of vancomycin to standard cefazolin prophylaxis was not superior to placebo for the prevention of surgical site infections in hip and knee arthroplasty surgery

Aims

This study aimed to assess the carbon footprint associated with total hip arthroplasty (THA) in a UK hospital setting, considering various components within the operating theatre. The primary objective was to identify actionable areas for reducing carbon emissions and promoting sustainable orthopaedic practices.

Healthcare associated infections (HAI) pose a major threat to patients admitted to hospitals, and infection rates following orthopaedic arthroplasty surgery are as high as 4%, while the infection rates are even higher after revision surgery. 405 nm High-Intensity Narrow Spectrum (HINS) light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in orthopaedic surgery. Cultured rat osteoblasts were exposed to 405 nm light to investigate if bactericidal doses of light could be used safely in the presence of mammalian cells. Cell viability was measured by MTT reduction and microscopy techniques, function by alkaline phosphatase activity, and proliferation by the BrdU assay. Exposures of up to a dose of 36 J/cm. 2. had no significant effect on osteoblast cell viability, whilst exposure of a variety of clinically relevant bacteria, to 36 J/cm. 2. resulted in up to 100% kill. Exposure to a higher dose of 54 J/cm. 2. significantly affected the osteoblast cell viability, indicating dose dependency. Work also demonstrated that 405 nm light exposure induces reactive oxygen species (ROS) production in both mammalian and bacterial cells, as shown by fluorescence generated from 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate dye. The mammalian cells were significantly protected from dying at 54 J/cm. 2. by catalase, which detoxifies H. 2. O. 2. Bacterial cells were significantly protected by sodium pyruvate (H. 2. O. 2. scavenger) and by a combination of free radical scavengers (sodium pyruvate, dimethyl thiourea (·OH scavenger), catalase) at 162 and 324 J/cm. 2. Thus the cytotoxic mechanism of 405 nm light in mammalian cells and bacteria is likely oxidative stress involving predominantly H. 2. O. 2. generation, with other ROS contributing to the damage. Additional work describing the potential for incorporation of this antimicrobial light within operating theatre lighting systems will also be discussed, and this, coupled with the cell viability and cytotoxicity results, suggests that 405 nm light could have great potential for continual patient safe decontamination during orthopaedic replacement surgeries and thereby reduce the incidence of infections

Objectives: To compare the results of various surgical approaches to the knee in primary arthroplasty surgery. Design: Systematic review with meta-analysis. Data Sources: Cochrane Bone, Joint, and Muscle Trauma group trials register (2007), Cochrane central register of controlled trials (Cochrane Library issue 2, 2007), Medline (1950 to February 2007), Embase (1974 to February 2007), CINAHL (1982 to February 2007), Pubmed, SCOPUS and ZETOC. If data was insufficient trialists were contacted via telephone, email or letter. Review methods: Randomised and quasi-randomised controlled trials comparing surgical approaches to the knee in patients undergoing primary arthroplasty surgery. Results: Twenty-three randomised, controlled trials (1282 patients, 1490 TKAs) were included. Midvastus vs Medial Parapatellar approach: Quadriceps function in the early post operative period was better preserved in the MV group. Post operative pain, blood loss and the need for LRR tended to be lower in the MV group. There was no difference in ROM, hospital stay, knee scores, complications or radiological alignment. Subvastus vs Medial Parapatellar approach: Quadriceps function was better preserved in the SV group up to 3 months post operatively. ROM was generally greater up to the 4 week time point. Post operative pain and blood loss was lower in the SV group. There was no difference in operative/tourniquet time, hospital stay, rate of LRR, or complications. Modified “Quadriceps sparing” Medial Parapatellar vs Mini-Subvastus (MSV) approach: A tendency for earlier restoration of SLR and better early ROM was noted in the MSV group. Midvastus vs Subvastus approach: The SV group suffered with significantly more pain at six months post operatively. Conclusions: Approaches preserving the quadriceps tendon improve the early extensor mechanism function and tend to decrease the need for LRR. Combined with a decrease blood loss and postoperative pain, these approaches improve early rehabilitation and allow for a more rapid recovery of knee function. However, these early improvements fail to provide any long term benefit, do not improve knee scores, or decrease the length of hospital stay

Introduction. Oral factor Xa inhibitors have recently been licensed for use as thromboprophylaxis in arthroplasty surgery. Phase IV trials have proven there efficacy in DVT/PE prevention with comparable rates in major adverse events, including major bleeding. We examined whether the introduction of rivaroxoban, an oral factor Xa inhibitor, increased total blood loss in patients undergoing primary arthroplasty surgery. Methods. Two groups were studied. The intervention group were prescribed rivaroxoban thrombophrophylaxis 6–10 hours post-surgery, and the control group were prescribed low molecular weight heparin (daltaparin 5,000u) 6–10 hours post-surgery. All other factors were kept constant. Pre- and post-operative haemoglobin levels (post-operative day 2) were recorded. Any requirement for transfusion was also documented. Actual drop in haemoglobin levels was compared between the two groups. Results. 91 patients were prescribed rivaroxoban (48 THR and 43 TKR), and 71 were included in the control group (34 THR and 37 TKR). Baseline pre-operative haemoglobin were comparable (p=0.43; 13.0 vs 13.2g/dL), however, post-operative blood loss was significantly increased in the rivaroxoban group (p=< 0.0001; 3.6 vs 2.8g/dL). Total knee replacements had a significant increase in post-operative blood loss in the rivaroxoban group (p=< 0.0001; 3.4 vs 2.6g/dL). Total hip replacement surgery had an increase in total blood loss in the rivaroxoban group, but this did not reach statistical significance (p=0.33; 3.8 vs 3.3g/dL). More patients undergoing TKR required transfusion in the rivaroxoban group (0.07% vs 0.03%). Conclusions. Oral factor Xa inhibitors significantly increase post-operative blood loss in total knee arthroplasty surgery when compared with LMWH. There is a subsequent increased requirement for blood transfusion and the potential complications related to bleeding and transfusion. These factors must be considered and balanced with the ease of oral anticoagulation when introducing these newer agents in arthroplasty patients

Purpose: To determine predictive factors for alloge-neic blood transfusion to aid in development of blood conservation strategies for the Hamilton arthroplasty population

Methods: A prospectively collected, retrospective study of 828 patients, who did not donate blood, treated with either primary total knee or total hip arthroplasty from 1998 to 2002 at Hamilton Henderson Hospital was carried out. A univariate analysis was performed to establish the relationship between all independent variables and the need for postoperative transfusion. Variables that were determined to have a significant relationship were included in a multivariate analysis

Results: The univariate analysis revealed a significant relationship between the need for postoperative blood transfusion and preoperative hemoglobin levels (p=0.000), age (P=0.000), and gender (P=0.005). However, the multivariate analysis only revealed significant relationship between the need for transfusion and pre-operative hemoglobin (P=0.000) and age (P=0.014). Patients with preoperative hemoglobin of > 150 g/L had a 10% risk of transfusion. Patients with preoperative hemoglobin of 141–150 g/L has 2.5 times greater risk, 131–140 g/L 4 times greater risk, 121–130 g/L 6 times greater risk, and < 120 25 times greater risk than patients with preoperative hemoglobin > 150 g/L.

Conclusions: The preoperative hemoglobin level and age were shown to predict the need for blood transfusion after total joint arthroplasty. These results of this will help to create guidelines for the Blood Conservation Program in HHSC.

Background: Infection in total joint replacement remains one of the most devastating post operative complications. The majority of these infections are still caused by organisms normally found on the skin. The use of adhesive wound drapes has become commonplace in orthopaedic surgery but frequently these are detached from the wound edges at the end of surgery allowing contamination of the wound.

Aim: To develop a technique to improve the adherence of wound drapes.

Methods: The first part of this study was to experiment with a number of techniques to prepare the skin preoperatively. We were able to identify that a combination of initial Betadine in alcohol preparation, followed by re-preparation of the operative site with Chlorhexidine in alcohol produced the best combination of drape adherence. In a consecutive series of 100 patients we have used our original technique of preparing the wound for 50 patients followed by a further 50 patients prepared with the new technique.

Results: In the initial patient group all of the adhesive drapes were detached enough to expose the skin edges in at least one part of the wound by the end of the surgical procedure. With the new technique we have had no detachments of the adhesive drape.

There have been no complications or skin reactions related to this method of skin preparation. There has been no significant difference in the incidence of early post operative wound infection.

Conclusion: This technique of operation site preparation provides an excellent means of preventing detachment of adhesive wound drapes. We have found it reliable, safe and effective to date and it adds little to the overall procedure time. We recommend this technique as a way of ensuring that the skin edges remain covered throughout primary and revision procedures.

Osteolysis and subsequent mechanical loosening often occurs in hip arthroplasties using polyethylene-on-ceramic (POC) bearings. This has prompted an ongoing search for alternative bearing surfaces. Ceramic-on-ceramic (COC) and metal-on-metal (MOM) prostheses are widely used, with good clinical results. Using hip simulator studies, we compared ceramic-on-metal (COM) and MOM prostheses.

We found COM pairings had 100-fold lower wear rates than MOM. The wear particles from both articulations were oval to round in shape and in the nanometer size range, with the COM producing smaller particles than the MOM. In both pairings, particle size decreased as the bearings bedded in. The volumetric particle loads were far smaller with COM bearing-surfaces than in currently-used MOM prostheses.

These findings have encouraged us to investigate the use of these novel bearing surfaces. Ethical approval has been obtained, and a prospective randomised clinical trial comparing POC, MOM, COC and COM bearing surfaces has started.

Introduction: Many papers present results and outcomes of patients undergoing TKR or THR, these are often available to the general population and health care community and health care commissioners. These results are used as a standard to be expected by the interested parties. Patients undergoing lower limb arthroplasty fall into groups that can be broadly divided into standard and complex. Complexity can be further subdivided into local site of surgery problems, general co-morbidity problems or both.

We have come up with a 4-part stratification based on the patient’s primary condition and comorbidities and have evaluated this for a single-surgeon cohort of TKR patients and a multi-surgeon group of THR patients. We present the results and the implications of the findings and highlight the usability of the system.

Methods: Retrospective review of patient’s notes and radiographs recording lenght of stay, early post operative complications, demographic data, medical co-morbidities and local site of surgery issues. This information was used to stratify patients into 4 groups. Complex Primary 0 -standard joint replacement in a fit patient with simple pattern arthritis, Complex Primary I -a fit patient with locally complex arthritis, Complex Primary II -medically unfit patient with simple arthritis and Complex Primary III -medically unfit patient with complex pattern arthritis. We evaluated this for a single-surgeon cohort of TKR patients and a multi-surgeon group of THR patients, a total of 250 patients.

Results: The complication rates between the four groups were analyzed using logistic regression analysis and this revealed a highly significant trend among the four groups (p< 0.0001). Lenght of stay data was analyzed using non-parametric analysis of variance. This revealed a significantly increased lenght of stay in the CI and CII groups compared to the C0 group. Compared to CP0 patients, we found a 3-fold increase in cumulative complication risk in the CPII group, a 4-fold increase in the CPIII group. There were similar trends between CP0 and CPI and between CPI and CPII.

Discussion and Conclusion: This classification system correlates and quantifies increasing primary joint replacement complexity with increasing postoperative complication rates and length of stay. It is of use in stratifying patients for preoperative planning, risk counselling, and surgeon selection. These noted increases mean that this system can identify patient groups likely to incur greater cost during their treatment. It is potentially reproducible and usable for other types of surgery and can be applied to larger patient groups via institutional or national joint registries.

Introduction: Between 1% and 5% of joint prostheses will become infected. The main bacteria involved in prosthetic infections are coagulase negative staphylococci, principally Staphylococcus epidermidis.

The introduction of the laminar flow theatre was responsible for a decrease in wound infection four and a half fold. Further research has found that total body exhaust suits were also responsible for a reduction in infection rate.

These exhaust suits include a toga hood, also supplied sterile and attached to the gown. There is no information from the manufacturers regarding microbial penetration of these hoods. Therefore we have performed an experiment to examine the potential for microbial penetration of these toga hoods, both when wet and dry.

Methods: Confluent lawns of Staphylococcus Epidermidis NCTC 11047 (Fig. 2) were created on two isosensitest agar plates by flood seeding the organism onto the plates, followed by incubation overnight at 37°C.

Both wet and dry toga circles were applied to the previously prepared lawns of Staphylococcus epidermidis NCTC 11047, with the internal surface in contact with the lawn. Swabbings were taken from the external surface of both wet and dry toga circles at regular intervals. The timing of the swabbings were: 1 min, 5 mins, 20 mins, and 60 mins. The swabs were then used to inoculate blood agar plates, which were incubated overnight at 37°C, after which they were examined for growth of Staphylococcus epidermidis.

Discussion: The results are conclusive: there is bacterial transmission from one side of the toga hood to the other. Therefore it is possible to transmit bacteria from the surgeon’s face across the toga material and into the operative field.

Introduction and Aims: The use of ‘superglue’ (2-Octylcyanoacrylate) in wound closure is well established in other surgical specialties, but not described in orthopaedics. The aim was to compare superglue with staples and subcuticular suture in a prospective randomised trial.

Method: One hundred and fifty patients admitted for a primary total knee or hip replacement were randomised to receive either clips, continuous subcuticular suture (3.0 Monocryl) or ‘superglue’ for wound closure. All knee replacements were mobilised on the day of surgery with CPM and hip replacements on the first post-operative day. Patients’ wounds were assessed on day one and at six weeks by a blinded observer.

Results: There were 80 hips and 70 total knee replacements performed; 51 wounds were closed with clips, 50 with suture and 49 with superglue. Mean duration of skin closure was significantly shorter with staples, and superglue was significantly faster than suture. There was no significant difference in the complication rates between the groups, including infection, dehiscence or allergic reaction. There was significantly more ooze by day one from the wounds closed with clips than the other two groups. Significantly more of the wounds closed with glue had no strike-through on to the dressing, and were therefore deemed to be ‘sealed’. Patient satisfaction at six weeks was significantly higher with superglue and suture than staples. The suture and super-glue groups had higher median scores on the Hollander wound evaluation scale than staples, however the difference was not statistically significant. Surgeon satisfaction with technique was highest with superglue and staples (no significant difference between the groups), and significantly higher than with subcuticular suture.

Conclusion: Superglue is safe to use for skin closure in primary knee and hip arthroplasty. Although closure with staples is faster, superglue is associated with less wound ooze and better patient satisfaction. The cosmetic result with superglue is comparable to that of subcuticular sutures but has a better surgeon satisfaction score.

Objectives: To compare the results of various surgical approaches to the knee in primary total knee arthroplasty (TKA) surgery.

Design: Systematic review with meta-analysis.

Data Sources: Cochrane Bone, Joint, and Muscle Trauma group trials register (2007), Cochrane central register of controlled trials (Cochrane Library issue 2, 2007), Medline (1950–2007), Embase (1974–2007), CINAHL (1982–2007), Pubmed, SCOPUS and ZETOC.

Review Methods: Randomised and quasi-randomised controlled trials comparing surgical approaches in patients undergoing primary TKA. Relative risks and 95% CIs were calculated for dichotomous outcomes, and weighted mean differences and 95% CIs calculated for continuous outcomes. Individually randomised trials were pooled whenever possible with the use of the fixed-effects model of Mantel-Haenszel.

Results: 53 articles were identified using our search strategy; of these, 32 were excluded from the systematic review. 21 trials involving 1082 patients (1170 TKAs) were included.

Midvastus (MV) vs Medial Parapatellar (MPP) approach:

Quadriceps function in the early post operative period was better preserved in the MV group. Post operative pain, blood loss and the need for LRR tended to be lower in the MV group.

Conclusions: Approaches preserving the quadriceps tendon improve the early extensor mechanism function and tend to decrease the need for LRR. Combined with a decrease in blood loss and postoperative pain, these approaches improve early rehabilitation and allow for a more rapid recovery of knee function. However, these early improvements fail to provide any long term benefit, do not improve knee scores, or decrease the length of hospital stay.

MIS tends to result in an improved early quadriceps function and decreased blood loss. However, these approaches are technically more demanding, result in longer operative times and provide no long-term benefit. There is concern that they result in a greater number of major complications and risk implant mal-alignment. Eversion of the patella seems to correlate with poor quadriceps function.

Introduction

New methods to reduce inpatient stay, post-operative complications and recovery time are continually being sought in surgery. Many factors affect length of hospital stay, such as, analgesia, patient and surgeon expectations, as well as provision of nursing care and physiotherapy. Development of the use of postoperative local anaesthetic infiltration delivered intra-articularly by a catheter appears to be an effective analgesic method which reduces patient's opioid requirements and allows early physiotherapy without motor blockade of muscles. Our study aimed to explore if the use of local anaesthetic infiltration intra-articularly following joint athroplasty affected the patient's duration of hospitalisation.

Arthroplasty procedures in low-income countries are mostly performed at tertiary centers, with waiting lists exceeding 12 to 24 months. Providing arthroplasty services at other levels of healthcare aims to offset this burden, however there is a marked paucity of literature regarding surgical outcomes. This study aims to provide evidence on the safety of arthroplasty at district level. Retrospective review of consecutive arthroplasty cases performed at a District Hospital (DH), and a Tertiary Hospital (TH) in Cape Town, between January 2015 and December 2018. Patient demographics, hospital length of stay, surgery related readmissions, reoperations, post-operative complications, and mortality rates were compared between cohorts. Seven hundred and ninety-five primary arthroplasty surgeries were performed at TH level and 228 at DH level. The average hospital stay was 5.2±2.0 days at DH level and 7.6±7.1 days for TH (p<0.05). Readmissions within 3 months post-surgery of 1.75% (4 patients) for district and 4.40% (35) for TH (p<0.05). Reoperation rate of 1 in every 100 patients at the DH and 8.3 in every 100 patients at the TH (p<0.05). Death rate was 0.4% vs 0.6% at district and TH respectively (p>0.05). Periprosthetic joint infection rate was 0.43% at DH and 2.26% at TH. The percentage of hip dislocation requiring revision was 0% at district and 0.37% at TH. During the study period, 228 patients received arthroplasty surgery at the DH; these patients would otherwise have remained on the TH waiting list. Hip and Knee Arthroplasty at District health care level is safe and may help ease the burden on arthroplasty services at tertiary care facilities in a Southern African context. Adequately trained surgeons should be encouraged to perform these procedures in district hospitals provided there is appropriate patient selection and adherence to strict theatre operating procedures

Aims. It is common practice for patients to have postoperative blood tests after total joint replacement (TJR). However, there have been significant improvements in perioperative care with arthroplasty surgery, and a drive to reduce the length of stay (LOS) and move towards day-case TJR. We should reconsider whether this intervention is necessary for all patients. Methods. This retrospective study included all patients who underwent a primary unilateral TJR at a single tertiary arthroplasty centre during a one-year period. Electronic medical records of 1,402 patients were reviewed for patient demographics, LOS, and American Society of Anesthesiologists (ASA) grade. Blood tests were examined to investigate the incidence of postoperative anaemia, electrolyte abnormalities, and incidence of acute kidney injury (AKI). Results. For total knee arthroplasties, preoperative (R = −0.22) and postoperative haemoglobin (R = 0.2) levels were both negatively correlated with LOS (p < 0.001). For all patients who had undergone a TJR, 19 patients (0.014%) required a blood transfusion postoperatively due to symptomatic anaemia. Risk factors identified were age, preoperative anaemia, and long-term aspirin use. Significant abnormal sodium levels were found in123 patients (8.7%). However, only 36 patients (2.6%) required intervening treatment. Risk factors identified were age, preoperative abnormal sodium level, and long-term use of non-steroidal anti-inflammatory drugs, angiotensin receptor blockers, and corticosteroids. Similarly, abnormal potassium levels were evident in 53 patients (3.8%), and only 18 patients (1.3%) required intervening treatment. Risk factors identified were preoperative abnormal potassium level, and long-term use of angiotensin-converting enzyme inhibitors and diuretics. The incidence of AKI was 4.4% (61 patients). Risk factors identified were age, increased ASA grade, preoperative abnormal sodium, and creatinine level. Conclusion. Routine blood tests after primary TJR is unnecessary for most patients. Blood tests should only be performed on those with identifiable risk factors such as preoperative anaemia and electrolyte abnormalities, haematological conditions, long-term aspirin use, and electrolyte-altering medications. Cite this article: Bone Jt Open 2023;4(5):357–362

Aims. Arthroplasty surgery of the knee and hip is performed in two to three million patients annually. Periprosthetic joint infections occur in 4% of these patients. Debridement, antibiotics, and implant retention (DAIR) surgery aimed at cleaning the infected prosthesis often fails, subsequently requiring invasive revision of the complete prosthetic reconstruction. Infection-specific imaging may help to guide DAIR. In this study, we evaluated a bacteria-specific hybrid tracer (. 99m. Tc-UBI. 29-41. -Cy5) and its ability to visualize the bacterial load on femoral implants using clinical-grade image guidance methods. Methods. 99m. Tc-UBI. 29-41. -Cy5 specificity for Stapylococcus aureus was assessed in vitro using fluorescence confocal imaging. Topical administration was used to highlight the location of S. aureus cultured on femoral prostheses using fluorescence imaging and freehand single photon emission CT (fhSPECT) scans. Gamma counting and fhSPECT were used to quantify the bacterial load and monitor cleaning with chlorhexidine. Microbiological culturing helped to relate the imaging findings with the number of (remaining) bacteria. Results. Bacteria could be effectively stained in vitro and on prostheses, irrespective of the presence of biofilm. Infected prostheses revealed bacterial presence on the transition zone between the head and neck, and in the screw hole. Qualitative 2D fluorescence images could be complemented with quantitative 3D fhSPECT scans. Despite thorough chlorhexidine treatments, 28% to 44% of the signal remained present in the locations of the infection that were identified using imaging, which included 500 to 2,000 viable bacteria. Conclusion. The hybrid tracer . 99m. Tc-UBI. 29-41. -Cy5 allowed effective bacterial staining. Qualitative real-time fluorescence guidance could be effectively combined with nuclear imaging that enables quantitative monitoring of the effectiveness of cleaning strategies. Cite this article: Bone Joint Res 2023;12(1):72–79

Ceramic bearing fractures are rare events, but mandate revision and implantation of new bearings. Revisions using metal heads have been reported to lead to gross volumetric head wear (due to abrasive retained ceramic micro-debris), cobalt toxicity, multi-organ failure and death. Such complications are widely published (50+ reports), yet we know that patients continue to be put at risk. Using data from the NJR and AOANJRR, this study seeks to compare the risk of re-revision and death by revision bearing combination following a ceramic bearing fracture. Data were extracted from the NJR and AOANJRR, identifying revisions for ceramic bearing fracture. Subsequent outcomes of survival, re-revision and death were compared between revision bearing combinations (ceramic-on-ceramic, ceramic-on-polyethylene, and metal-on-polyethylene). 366 cases were available for analysis from the NJR dataset (MoP=34, CoP=112, CoC=221) and 174 from the AOANJRR dataset (MoP=17, CoP=44, CoC=113). The overall incidence rate of adverse outcome (revision or death) was 0.65 for metal heads and 0.23 for ceramic head articulations (p=0.0012) across the whole time period (NJR). Kaplan-Meir survival estimates demonstrate an increased risk of both re-revision and death where a metal head has been used vs a ceramic head following revision for ceramic fracture. There are few decisions in arthroplasty surgery that can lead to serious harm or death for our patients, but revision using a metal head following ceramic bearing fracture is one of them. This study enhances the signal of what is already known but previously only reported as inherently low-level evidence (case reports and small series) due to event rarity. Use of a metal head in revision for ceramic fracture represents an avoidable patient safety issue, which revision guidelines should seek to address