Background

While many studies have investigated long-term outcomes after lower limb arthroplasty, rather less is known about the trajectory of short-term outcomes in the first post-operative year. It is difficult for a surgeon to know when, in terms of disease severity, it is best to operate, or to make an accurate prediction of the patient pattern of post-operative recovery. We explored the trajectory of change in pain and function following primary hip and knee arthroplasty and the influence of pre-operative self-reported symptoms on post-operative improvements.

Administration of perioperative antibiotic prophylaxis (AP) reduces the risk of prosthetic joint infection (PJI) following primary total hip (THA) and knee (TKA) arthroplasty. The optimal type of antibiotic used, and duration of prophylaxis are subject to debate. We compared the risk of revision surgery for PJI in the first year following THA and TKA by AP regimen. A national survey collecting information on hospital-level AP regimen policy was conducted across the Netherlands and linked to data from the LROI arthroplasty registry for 2011–2015. PJI status was defined using the surgical indication reported at revision by surgeons in the registry form. Restricted cubic splines Poisson model adjusted for hospital clustering were used to conduct the comparisons on 130,712 THAs and 111,467 TKAs performed across 99 institutions. These included 399 THAs and 303 TKAs revised for an indication of PJI. Multiple shot of Cefazolin (MCZ), of cefuroxime (MCX) and single shot of Cefazolin (SCZ) were respectively administrated to 87%, 4% and 9% of patients. For THA, the rates of revision for PJI were respectively 31/10,000 person-years 95%CI[28, 35], 39[25, 59] and 23[15, 34] in the groups which received MCZ, MCX and SCZ; respectively, the rates for TKA were 27[24, 31], 40[24, 62] and 24[16, 36]. No evidence of difference between AP regimens was found in the unadjusted and adjusted model (age, gender, BMI and ASA grade). Further work is advocated to confirm whether there is an association between AP regimen collected at patient-level and the risk of subsequent revision for PJI.

Abstract. Introduction. Intra-articular distal humerus OTA type C fractures are challenging to treat. When osteosynthesis is not feasible one can choose to do a primary arthroplasty of elbow or manage non-operatively. The indications for treatment of this fracture pattern are evolving. Objectives. We present our outcomes and complications when this cohort of patients was managed with either open reduction internal fixator (ORIF), elbow arthroplasty or non-operatively. Methods. Retrospective study to include OTA type C2 and C3 fracture distal humerus of 36 patients over the age of 50 years managed with all the three modalities. Patient's clinical notes and radiographs were reviewed. Results. Between 2016 and 2022, 21 patients underwent ORIF – group 1, 10 patients were treated with arthroplasty – group 2 and 5 were managed conservatively- group 3. The mean age of patients was 62 years in group 1, 70 years in group 2 and 76 years in group 3. The mean range of movement (ROM) arc achieved in the group 1 & 2 was 103 while group 3 was 68. At least follow up was 6 months. 5 patients in group 1 underwent metalwork removal and 2 patients in group 3 under arthroplasty. Conclusion. The outcomes of arthroplasty and ORIF are comparable, but reoperation rates and stiffness were higher in ORIF and conservative group. Surgeon choice and patient factors play important role in decision towards choosing treatment modality. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

This study compared the pullout forces of the initial implantation and the “cement-in-cement” revision technique for short and standard-length (125 mm vs. 150 mm) Exeter. ®. V40 femoral stems used in total hip arthroplasty (THA). The idea that the pullout force for a double taper slip stem is relative to the force applied to the femur and that “cement-in-cement” revision provides the same reproduction of force. A total sample size of 15 femoral stems were tested (Short, n = 6 and Standard, n = 9). 3D printed fixtures for repeatable sample preparation were used to minimize variance during testing. To promote stem subsidence and to simulate an in vivo environment, the samples were placed in an incubator at 37°C at 100% humidity and experienced a constant compressive loading of 1335 N for 14 days. The samples underwent a displacement-controlled pullout test. After the initial pullout test, “cement-in-cement” revision will be performed and tested similar to the initial implantation to observe the efficacy of the revision technique. To compare the pullout forces between the two groups, a Kruskal-Wallis test using a significance level of 0.05 was conducted. The mean maximum pullout force for the short and standard-length femoral stems were 3939 ± 1178 N and 5078 ± 1168 N, respectively. The Kruskal-Wallis test determined no statistically significant difference between the two groups for the initial implantation (p = 0.13). The “cement-in-cement” revision pullout force will be conducted in future testing. This study demonstrated the potential use of short stem designs for THA as it provides similar levels of fixation as the standard-length femoral stem. The potential benefits for using a short stem design would be providing similar load transfer to the proximal femur, preserving proximal metaphyseal femoral bone in primary replacement, and reducing the invasiveness during revision

Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

Patients report similar or better pain and function before revision hip arthroplasty than before primary arthroplasty but poorer outcomes after revision surgery. The trajectory of post-operative recovery during the first 12 months and any differences by type of surgery have received little attention. We explored the trajectories of change in pain and function after revision hip arthroplasty to 12-months post-operatively and compared them with those observed after primary hip arthroplasty. We conducted a single-centre UK cohort study of patients undergoing primary (n = 80) or revision (n = 43) hip arthroplasty. WOMAC pain and function scores and 20-metres walking time were collected pre-operatively, at 3 and 12-months post-operatively. Multilevel regression models were used to chart and compare the trajectories of post-operative change (0–3 months and 3–12 months) between the types of surgery. Patients undergoing primary arthroplasty had a total hip replacement (n=74) or hip resurfacing (n=6). Osteoarthritis was the indication for surgery in 92% of primary cases. Patients undergoing revision arthroplasty had revision of a total hip arthroplasty (n=37), hemiarthroplasty (n=2) or hip resurfacing (n=4). The most common indication for revision arthroplasty was aseptic loosening (n=29); the remaining indications were pain (n=4), aseptic lymphocyte-dominated vasculitis-associated lesion (n=4) or other reasons (n=6). Primary (87%) and revision arthroplasties (98%) were mostly commonly performed via a posterior surgical approach. The improvements in pain and function following revision arthroplasty occurred within the first 3-months following operation (WOMAC-pain, p<0.0001; WOMAC-function, p<0.0001; timed 20-metres walk, p<0.0001) with no evidence of further change beyond this initial period (p>0.05). While the pattern of recovery after revision arthroplasty was similar to that observed after primary arthroplasty, improvements in the first 3-months were smaller after revision compared to primary arthroplasty (p<0.0001). Patients listed for revision surgery reported lower pre-operative pain levels (p=0.03) but similar post-operative levels (p=0.268) compared to those undergoing primary surgery. At 12-months post-operation patients who underwent a revision arthroplasty had not reached the same level of function achieved by those who underwent primary arthroplasty (WOMAC-function p=0.015; Time walk p=0.004). Patients undergoing revision hip arthroplasty should be informed that the majority of their improvement will occur in the first 3-months following surgery and that the expected improvement will be less marked than that experienced following primary surgery. More research is now required to 1.) identify whether specific in-patient and post-discharge rehabilitation tailored towards patients undergoing revision arthroplasty would improve or achieve equivalent outcomes to primary surgery and 2.) whether patients who are achieving limited improvements at 3-months post-operative would benefit from more intensive rehabilitation. This will become all the more important with the increasing volume of revision surgery and the high expectations of patients who aspire to a disease-free and active life

Pre-operative anaemia can present in up to 30% of elective arthroplasty patients. The presence of anaemia increases the risk of requiring blood transfusion post-operatively as well as acts as an independent risk factor for poor outcome such as prosthetic joint infection. Recent international consensus on this topic has recommended a specific care pathway for screening patients with pre-operative anaemia using a simple bedside Heaemacue finger-prick test to detect in a simple and cost-effective manner, and then allow treatment of preoperative anaemia. This pathway was therefore incorporated in our trust. This was a retrospective study done at a single tertiary-referral arthroplasty centre. Our data collection included the Heamacue test results and formal haemoglobin levels if they were performed as well as compliance and costs of each of the tests for patients listed for an elective shoulder, hip and knee arthroplasty between September and December 2018. Medical records and demographics were also collected for these patients for subgroup analysis. Our exclusion criteria comprised patients listed for revision arthroplasty surgery. 87 patients were included in this study. Our compliance rate was 15%. The mean difference between a Haemacue test and a formal FBC result was only 17.6g/L suggesting that it has a reasonably high accuracy. With regards to costs, we found that a Haemacue test costs £2, compared to £7.50 for a full blood count and Haematinics combined. This gave an overall cost saving of £5.50 per patient. Extrapolation of this date locally for 2017 at our hospital, where 1575 primary joint arthroplasties were done, a cost saving of £8,662.5 could have been achieved. Within the UK using data extrapolated from the National Joint Registry a total of £1,102,205.5 (1,221,894 Euros) could have been saved. The use of a single, Haemacue test to screen for pre-operative anaemia in elective arthroplasty patients is more cost effective compared to a formal full count and haematinics tests. However, we found that compliance with the care pathway is variable due to system limitations. This may be addressed through implementing changes to our electronic system in which patients are booked for surgery. We also noted a significant cost reduction if this pathway were to be used Nation-wide. Thus, we encourage other centres to consider the use of the Haemacue test pre-operatively in elective arthroplasty instead of formal full blood counts at the time of decision to treat with arthroplasty; this allows sufficient time for correction of pre-operative anaemia thus improving patient outcomes from arthroplasty

Prosthetic joint infection (PJI) is an uncommon but serious complication of hip and knee replacement. We investigated the rates of revision surgery for the treatment of PJI following primary and revision hip and knee replacement, explored time trends, and estimated the overall surgical burden created by PJI. We analysed the National Joint Registry for England and Wales for revision hip and knee replacements performed for a diagnosis of PJI and their index procedures from 2003–2014. The index hip replacements consisted of 623,253 primary and 63,222 aseptic revision hip replacements with 7,642 revisions subsequently performed for PJI; for knee replacements the figures were 679,010 primary and 33,920 aseptic revision knee replacements with 8,031 revisions subsequently performed for PJI. Cumulative incidence functions, prevalence rates and the burden of PJI in terms of total procedures performed as a result of PJI were calculated. Revision rates for PJI equated to 43 out of every 10,000 primary hip replacements (2,705/623,253), i.e. 0.43%(95%CI 0.42–0.45), subsequently being revised due to PJI. Around 158 out of every 10,000 aseptic revision hip replacements performed were subsequently revised for PJI (997/63,222), i.e. 1.58%(1.48–1.67). For knees, the respective rates were 0.54%(0.52–0.56) for primary replacements, i.e. 54 out of every 10,000 primary replacements performed (3,659/679,010) and 2.11%(1.96–2.23) for aseptic revision replacements, i.e. 211 out of every 10,000 aseptic revision replacements performed (717/33,920). Between 2005 and 2013, the risk of revision for PJI in the 3 months following primary hip replacement rose by 2.29 fold (1.28–4.08) and after aseptic revision by 3.00 fold (1.06–8.51); for knees, it rose by 2.46 fold (1.15–5.25) after primary replacement and 7.47 fold (1.00–56.12) after aseptic revision. The rates of revision for PJI performed at any time beyond 3 months from the index surgery remained stable or decreased over time. From a patient perspective, after accounting for the competing risk of revision for an aseptic indication and death, the 10-year cumulative incidence of revision hip replacement for PJI was 0.62%(95%CI 0.59–0.65) following primary and 2.25%(2.08–2.43) following aseptic revision; for knees, the figures were 0.75%(0.72–0.78) following primary replacement and 3.13%(2.81–3.49) following aseptic revision. At a health service level, the absolute number of procedures performed as a consequence of hip PJI increased from 387 in 2005 to 1,013 in 2014, i.e. a relative increase of 2.6 fold. While 70% of those revisions were two-stage, the use of single stage revision increased from 17.6% in 2005 to 38.5% in 2014. For knees, the burden of PJI increased by 2.8 fold between 2005 and 2014. Overall, 74% of revisions were two-stage with an increase in use of single stage from 10.0% in 2005 to 29.0% in 2014. Although the risk of revision due to PJI following hip or knee replacement is low, it is rising. Given the burden and costs associated with performing revision joint replacement for prosthetic joint infection and the predicted increased incidence of both primary and revision hip replacement, this has substantial implications for service delivery

We compared the peripheral blood and periprosthetic tissues of 53 patients at revision arthroplasty with those of 30 patients at primary arthroplasty to determine whether there is a systemic difference in lymphocytes in patients with worn hip implants. The absolute number and relative proportion of lymphocytes bearing CD2, CD3, CD4, CD8, CD16, CD19, HLA-DR, kappa and lambda antigens were compared with the levels of IL-1β, IL-6 and PGE. 2. in the pseudosynovial membrane as well as with a semiquantitative estimate of metal and polyethylene particles, necrosis and chronic inflammation and the total concentration of metals within the periprosthetic tissues. There was a significant increase in the relative proportion of CD2-positive T-cells and CD16-positive natural killer cells in the peripheral blood at revision arthroplasty compared with primary arthroplasty and an increased proportion of CD8-positive T-cells and a decreased ratio of CD4 to CD8 (helper inducer/suppressor cytotoxic cells). Three control patients, who went on to have revision surgery, had values at primary arthroplasty which were similar to those of patients at the time of revision surgery. These differences did not correlate with the local concentration of metal, plastic or cement or inflammatory response or the type of prosthesis. An inverse correlation was noted between the necrosis in the periprosthetic tissue and both the local production of IL-6 and the absolute numbers of T-cells in peripheral blood. We conclude that there may be several cell-mediated systemic immune responses to aseptic loosening, at least one of which may be directly related to events in the periprosthetic tissues. We cannot exclude the possibility that the changes in the proportion of CD8-positive cells reflected a predisposition, rather than a reaction, to loosening of the implant

Background. Since it's establishment in 2007, the National Hip Fracture Database [NHFD] has been the key driving force in improving care for hip fracture patients across the UK. It has facilitated the setting of standards to which all musculoskeletal units are held, and guides service development to optimise outcomes in this group of patients. As with any audit, the ability to draw conclusions and make recommendations for changes in practise relies on the accuracy of data collection. This project aimed to scrutinise the data submitted to the NHFD from a Major Trauma Centre [MTC], focusing on procedure coding, and discuss the implications of any inaccuracies. Method. The authors performed a retrospective analysis of all procedure coding data entered into the NHFD from July 2009 to July 2014 at Cambridge University Hospitals NHS Foundation Trust. We examined 1978 cases for discrepancies, comparing procedure codes entered into the NHFD with post-procedure imaging and operative notes. Results. The procedure coding data submitted to the NHFD was highly inaccurate, with incorrect procedure codes in 24% of the 1978 cases reviewed. In particular, coding of cemented total arthroplasty and cemented bipolar hemiarthroplasty, with coding errors in registry data of 42% and 39% respectively. Of the 67 THRs performed only 52% were correctly coded for, and only 626 of the 915 hemiarthroplasties (68%). 16% of cannulated hip screws actually underwent primary arthroplasty. Conclusions. This study highlights the inaccuracy of coding data entered into the NHFD from a Major Trauma Centre, with data on arthroplasty being particularly inadequate. The unreliability of procedure data leaves us unable to evaluate surgical treatment strategies using the NHFD. This has worrying implications for standard setting, service development and, consequently, patient care. Level of evidence. 2c

Introduction. Acute kidney injury is a recognised post-operative complication in primary joint replacement. Recently it has been demonstrated that antibiotic regimen can significantly impact on the proportion of patients who develop acute kidney impairment post-operatively. Within our unit an increased rate of acute kidney injury had been noted post-operatively over the last 5 years. This increase followed the introduction of a rapid recovery protocol for arthroplasty patients. Our aim was determine whether we could identify a causative factor or those who were at increased risk of post-operative renal impairment. Methods. Data were collected for 413 patients initially retrospectively but continued prospectively. Univariable and multivariable analysis was performed to determine any causative factors. The primary increase was 150% increase in baseline creatinine, but as some authors recognise an increase in 125% this was also analysed. Results. Within the 12 month period studied 23.3% of patients developed acute kidney injury, with an increase of 125% of their baseline creatinine. 8.23% of patients developed an increase of 150% in their creatinine levels. Age, previous renal failure and the pre-operative use of an ACE inhibitor were found to be statistically higher in the renal failure group. The uni-variable analysis also demonstrated that patients who received a small volume of post-operative intravenous fluids had a lower rate of renal failure than those who received no fluids (10% vs. 23%; p = 0.04). The multivariable regression analysis demonstrated that age was the only statistically significant positive predictive factor in developing renal failure. Antibiotic regimen had no effect. Discussion. Renal impairment has significant impact on patient morbidity and post-operative management. It increases the length of stay, and may potentially require more invasive therapy. We have demonstrated that the identified risk factors are non-modifiable but that a gentamicin and teicoplanin regimen was not an implicated causative factor

There is no diagnostic, non-invasive method for the early detection of loosening after total hip arthroplasty. In a pilot study, we have analysed two serum markers of bone remodelling, procollagen I C-terminal extension peptide (PICP) and cross-linked N-terminal telopeptide (NTx), as well as the diagnostic performance of NTx for the assessment of osteolysis. We recruited 21 patients with loosening (group I), 18 with a well-fixed prosthesis (group II) and 17 at the time of primary arthroplasty for osteoarthritis (OA) (group III). Internal normal reference ranges were obtained from 30 healthy subjects (group IV). The serum PICP level was found to be significantly lower in patients with OA and those with loosening, when compared with those with stable implants, while the NTx level was significantly increased only in the group with loosening, suggesting that collagen degradation depended on the altered bone turnover induced by the implant. This hypothesis was reinforced by the finding that the values in the pre-surgery patients and stable subjects were comparable with the reference range of younger healthy subjects. A high specificity and positive predictive value for NTx provided good diagnostic evidence of agreement between the test and the clinical and radiological evaluations. The NTx level could be used to indicate stability of the implant. However, further prospective, larger studies are necessary

Recent debate about changing population demographics and growing demands of younger patients has suggested a future explosion in the requirements for primary and revision lower limb arthroplasty (TKA/THA). This could represent a significant challenge for healthcare providers. This study aimed to predict the demands for lower limb arthroplasty in Scotland from 2010–2035. Population figures (2004–2010) and projected population data (five year increments) were obtained from the National Records of Scotland. The numbers of arthroplasties from 2004–2010 were provided by the Scottish Arthroplasty Project. Data were divided into three age groups (40–69, 60–79, 80+). The first model used mean incidence for each age group from 2006–2010 applied to the projected population figures. The second used linear regression to give predicted incidences 2015–2035 which were then applied to the projected population. The third-for revisions – used incidence per number of primary arthroplasties. For primary TKA model 1, comparing to 2010, showed demand increasing by 10% in 2020 and by 31% (to 8,650 procedures) in 2035. Model 2 gave increases of 60% and 161% respectively. An increase was found across all age groups with 60–79 more than doubling and 80+ increasing fourfold by 2035 (model 2). The revision TKA models predicted between 670 and 2,000 procedures by 2035. For primary THA models 1 and 2 showed demand increasing by 40% in 2020 and then by 60% and 110% (11,000 and 14,500 procedures) in 2035 respectively. All age groups had increasing demand with 60–79 doubling and 80+ tripling by 2035 (model 2). The revision THA models predicted between 1,300 and 2,100 procedures by 2035. These projections show large increases in the numbers of both primaries and revisions over the next two decades. They highlight that current resources may be insufficient or the selection criteria for surgery may need to be revisited

We investigated the antibiotic concentration in fresh-frozen femoral head allografts harvested from two groups of living donors. Ten samples were collected from patients with osteoarthritis of the hip and ten from those with a fracture of the neck of the femur scheduled for primary arthroplasty. Cefazolin (1 g) was administered as a pre-operative prophylactic antibiotic. After storage at −80°C for two weeks the pattern of release of cefazolin from morsellised femoral heads was evaluated by an in vitro broth elution assay using high-performance liquid chromatography. The bioactivity of the bone was further determined with an agar disc diffusion and standardised tube dilution bioassay. The results indicated that the fresh-frozen femoral heads contained cefazolin. The morsellised bone released cefazolin for up to four days. The concentration of cefazolin was significantly higher in the heads from patients with osteoarthritis of the hip than in those with a fracture. Also, in bioassays the bone showed inhibitory effects against bacteria. We concluded that allografts of morsellised bone from the femoral head harvested from patients undergoing arthroplasty of the hip contained cefazolin, which had been administered pre-operatively and they exhibited inhibitory effects against bacteria in vitro

The long-term biological effects of wear debris are unknown. We have investigated whether there is any evidence of cumulative mutagenic damage in peripheral blood lymphocytes of patients undergoing revision arthroplasty of predominantly metal-on-plastic total hip replacements compared with those at primary arthroplasty. There was a threefold increase in aneuploidy and a twofold increase in chromosomal translocations which could not be explained by the confounding variables of smoking, gender, age and diagnostic radiographs. In the patients with TiVaAl prostheses there was a fivefold increase in aneuploidy but no increase in chromosomal translocations. By contrast, in patients with cobalt-chrome prostheses there was a 2.5-fold increase in aneuploidy and a 3.5-fold increase in chromosomal translocations. In six patients with stainless-steel prostheses there was no increase in either aneuploidy or chromosomal translocations. Our results suggest that future epidemiological studies of the putative long-term risks of joint replacement should take into account the type of alloy used in the prosthesis

INTRODUCTION. Warfarin remains the treatment of choice for the majority of patients with venous thromboembolism, atrial fibrillation and valvular heart disease or valve replacement unless contraindicated. Poor management of patients on warfarin often leads to delay in surgery, life threatening bleeding during or after operation and unnecessary delay in discharge from hospitals in United Kingdom. METHODS. We carried out a prospective study on patients who were on warfarin and underwent elective and emergency orthopaedic procedures during period of study- August 2007 to April 2008. All patients included in the study were identified from admission notes during period of study. All data regarding indications for warfarin, pre and post procedures INR, elective or emergency orthopaedic procedures and complications were collected using a standard proforma. RESULTS. 18 patients, 12 male and 6 female were included into the study. Patients' age ranged from 47-87 with mean of 76. The indications for warfarin therapy were atrial fibrillation in 12 patients, deep vein thrombosis in 5 patients and left ventricular aneurysm in 1 patient. 18 procedures, 10 elective and 8 emergency orthopaedic procedures were carried out during period of study. Elective procedures - 7 primary joint arthroplasty, 1 revision hip arthroplasty, 1 removal of metalwork and 1 metatarsophalangeal joint fusion. Emergency procedures - 4 hip hemiarthroplasty, 2 dynamic hip screw fixation, 1 external fixator application and 1 open reduction and internal fixation of ankle. All elective admission patients were pre-assessed in clinic prior to admission and were advised to stop warfarin based on their INR level. Patients with INR 2-3 had their warfarin stopped 4 days prior to surgery while patients with INR 3-4.5 had their warfarin stopped 5 days prior to surgery. This group of patients had their INR check on admission and ranged from 1.1-1.5. This group of patients had no reversal therapy and no cancellations were made to their operation. 8 emergency admission patients had INR of 1.4-4.7 on admission with mean of 2.7. 5 patients had reversal therapy while 3 patients had no reversal therapy. Pharmacological methods used to reduce the INR were fresh frozen plasma in 1 patient and Vitamin K in 4 other patients. 2 patients that received reversal therapy had operation on day 1, 2 on day 3 and 1 on day 5. 1 patient that had no reversal therapy was operated on day 1, 1 on day 3 and 1 on day 5. Patient that received no reversal therapy and operated on day 5 of admission died post-operatively from medical complications. Mean delay for patient that had reversal therapy was 2.2 days compared to 3 days in patient with no reversal therapy. All patients in this study had prophylactic low molecular weight heparin while off warfarin. Patients were recommenced on their normal dose of warfarin the day after their operation. DISCUSSION & CONCLUSIONS. We conclude that patients on warfarin with INR 2-3 should have their warfarin stopped 4 days prior to surgery while patients with INR 3-4.5 should stop their warfarin 5 days prior to elective surgery. Trauma patients on warfarin requiring operation should have their INR reversed on admission to shorten delay in waiting time and improve outcomes

Summary Statement. Service industry metrics (the net promoter score) are being introduced as a measure of UK healthcare satisfaction. Lower limb arthroplasty, as a ‘service’, scores comparably with the most successful commercial organisations. Background. Satisfaction with care is important to both the patient and the payer. The Net Promoter Score, widely used in the service industry, has been recently introduced to the UK National Health Service as an overarching metric of patient satisfaction and to monitor performance. This questionnaire asks ‘customers’ if they would recommend a service or products to others. Scores range from −100 (everyone is a detractor) to +100 (everyone is a promoter). In industry, a positive score is well regarded, with those over 50 regarded as excellent. Our aims were to assess net promoter scores for joint arthroplasty, to compare these scores with direct measures of patient satisfaction, and to evaluate which factors contributed to net promoter response. Methods. 6912 individuals undergoing primary lower limb joint replacement over a five year period (Jan 2007 – Dec 2011) took part in a prospective cohort study at a single NHS University hospital. Net promoter score, clinical outcomes as measured by PROMS (Oxford Hip or Knee Score and SF-12 score), multi-faceted patient satisfaction questionnaire, demographic data and length of hospital stay were recorded. Data was collected preoperatively and at 1 year post-surgery. Multivariate regression was performed to determine which factors could predict an outcome of ‘promoter’ and ‘detractor’ at 1 year post-surgery. Significance was accepted at p = 0.1 to accommodate the confounding effect of other variables. Results. Net promoter scores for knee and hip replacements were 49 and 71 respectively. Strong correlation was seen between overall satisfaction and whether the patient would recommend the operation to another (r = 0.637), though regression of these factors was modest (R. 2. = 0.406). Only 4 factors were relevant to the net promoter response: pain relief (OR 2.13, CI 1.83 – 2.49), meeting expectations (OR 2.57, CI 2.24 – 2.97), hospital experience (OR 2.33, CI 2.03 – 2.68) and arthroplasty type (OR 2.31, CI 1.68 – 3.17). These factors drove a model able to explain 95% of the variation in net promoter score. Conclusions. This is the first analysis of net promoter score for joint arthroplasty, and demonstrates values that compare favourably with the services provided by the most successful commercial organizations. The UK Department of Health describes this score as a measure of patient satisfaction. This is perhaps not completely accurate, as only a third of the variation in one response can be explained by the other, suggesting that although clearly related, these concepts are not the same. Pain relief, meeting of expectations of surgery, the hospital experience and whether the hip or knee joint is replaced are the only relevant factors in determining the net promoter response. Factors thought to influence clinical outcome such as depression, number of comorbidities, age and gender carry no influence with this metric

Objectives

The objective of this study was to develop a test for the rapid (within 25 minutes) intraoperative detection of bacteria from synovial fluid to diagnose periprosthetic joint infection (PJI).