Total joint arthroplasty is commonly associated with post-operative anemia. Blood conservation programs have been developed to optimise patients prior to surgery. Epoetin Alfa (Eprex) or intravenous (IV) iron transfusions are two modalities that can be used pre-operatively to optimise hemoglobin and ferritin levels. There are, however, potential complications and increased costs associated with their use. Oral iron is a less costly option for those undergoing surgery but requires more time to take effect. There are no studies to date that examine the effects of an early screening program utilising oral iron supplementation prior to total joint arthroplasty. The purpose of this study is to evaluate the effect of implementing early pre-operative oral iron supplementation on patients prior total joint arthroplasty. A retrospective review of patients undergoing total joint arthroplasty was performed using our institution clinical informatics database. We identified all patients seen in pre-admission clinic (PAC) between Jan 1, 2009 and March 31, 2010 representing our control group. We then identified all patients seen in PAC between October 1, 2012 and December 31, 2013. Patients in this cohort received screening blood work when booked for surgery, and oral iron supplementation was given to patients with hemoglobin of less than 135g/L or ferritin less than 100ug/L, thus representing our treatment group. Patients undergoing revision, uni-compartment knee arthroplasty and bilateral arthroplasties were excluded from the study. Pearson Chi-Square tests were used to calculate significance between groups with main outcomes including pre-admission hemoglobin, and pre-operative requirements for Eprex or IV iron. In our control group, we identified 354 patients (25.6%) with hemoglobin less than 130 g/L at time of pre-admission clinic. In our treatment group, this number dropped significantly to only 16.4% of patients (p<0.005). Implementation of an early screening program using oral iron supplementation resulted in a decrease in the number of patients with hemoglobin lower than 130 g/L at the time of pre-admission clinic. There was also a significant decrease in the use of Eprex and IV iron pre-operatively in the patients in the early screening program. These results encourage the use of early oral iron supplementation for patients with hemoglobin less than 135 g/L or ferritin less than 100ug/L in order to optimise patients prior to total joint arthroplasty

Biodegradable metals as orthopaedic implant materials receive substantial scientific and clinical interest. Marketed cardiovascular products confirm good biocompatibility of iron. Solid iron biodegrades slowly in vivo and has got supra-physiological mechanical properties as compared to bone and porous implants can be optimized for specific orthopaedic applications. We used Direct Metal Printing (DMP)3 to additively manufacture (AM) scaffolds of pure iron with fine-tuned bone-mimetic mechanical properties and improved degradation behavior to characterize their biocompatibility under static and dynamic 3D culture conditions using a spectrum of different cell types. Atomized iron powder was used to manufacture scaffolds with a repetitive diamond unit cell design on a ProX DMP 320 (Layerwise/3D Systems, Belgium). Mechanical characterization (Instron machine with a 10kN load cell, ISO 13314: 2011), degradation behavior under static and dynamic conditions (37ºC, 5% CO2 and 20% O2) for up of 28 days, with μCT as well as SEM/energy-dispersive X-ray spectroscopy (EDS) (SEM, JSM-IT100, JEOL) monitoring under in vivo-like conditions. Biocompatibility was comprehensively evaluated using a broader spectrum of human cells according to ISO 10993 guidelines, with topographically identical titanium (Ti-6Al-4V, Ti64) specimen as reference. Cytotoxicity was analyzed by two-way ANOVA and post-hoc Tukey's multiple comparisons test (α = 0.05). By μCT, as-built strut size (420 ± 4 μm) and porosity of 64% ± 0.2% were compared to design values (400 μm and 67%, respectively). After 28 days of biodegradation scaffolds showed a 3.1% weight reduction after cleaning, while pH-values of simulated body fluids (r-SBF) increased from 7.4 to 7.8. Mechanical properties of scaffolds (E = 1600–1800 MPa) were still within the range for trabecular bone, then. At all tested time points, close to 100% biocompatibility was shown with identically designed titanium (Ti64) controls (level 0 cytotoxicity). Iron scaffolds revealed a similar cytotoxicity with L929 cells throughout the study, but MG-63 or HUVEC cells revealed a reduced viability of 75% and 60%, respectively, already after 24h and a further decreased survival rate of 50% and 35% after 72h. Static and dynamic cultures revealed different and cell type-specific cytotoxicity profiles. Quantitative assays were confirmed by semi-quantitative cell staining in direct contact to iron and morphological differences were evident in comparison to Ti64 controls. This first report confirms that DMP allows accurate control of interconnectivity and topology of iron scaffold structures. While microstructure and chemical composition influence degradation behavior - so does topology and environmental in vitro conditions during degradation. While porous magnesium corrodes too fast to keep pace with bone remodeling rates, our porous and micro-structured design just holds tremendous potential to optimize the degradation speed of iron for application-specific orthopaedic implants. Surprisingly, the biological evaluation of pure iron scaffolds appears to largely depend on the culture model and cell type. Pure iron may not yet be an ideal surface for osteoblast- or endothelial-like cells in static cultures. We are currently studying appropriate coatings and in vivo-like dynamic culture systems to better predict in vivo biocompatibility

Introduction. Major trauma during military conflicts involve heavily contaminated open fractures. Staphylococcus aureus (S. aureus) commonly causes infection within a protective biofilm. Lactoferrin (Lf), a natural milk glycoprotein, chelates iron and releases bacteria from biofilms, complimenting antibiotics. This research developed a periprosthetic biofilm infection model in rodents to test an Lf based lavage/sustained local release formulation embedded in Stimulin beads. Method. Surgery was performed on adult rats and received systemic Flucloxacillin (Flu). The craniomedial tibia was exposed, drilled, then inoculated with S. aureus biofilm. A metal pin was placed within the medullary cavity and treatments conducted. Lf in lavage solutions: The defect was subject to 2× 50 mL lavage with 4 treatment groups (saline only, Lf only, Bactisure with Lf, Bactisure with saline). Lf embedded in Stimulin beads: 4 bead types were introduced (Stimulin only, Lf only, Flu only, Lf with Flu). At day 7, rats are processed for bioluminescent and X-ray imaging, and tibial explants/pins collected for bacterial enumeration (CFU). Results. Rats without treatments established a mean infection of 2×106 CFU/tibia. 4 treatment groups with a day 0, one-off lavage demonstrated >95% reduction in bacterial load 7 days post-op, with a reduction in CFU from 1×106/tibia down to 1×104/tibia. There was no statistically significant difference between each group (p = 0.55 with one way ANOVA). The stimulin bead experiments are ongoing and complete results will be obtained in the end of July. Conclusions. This research demonstrated a clinically relevant animal model of implanted metalware that establishes infection. No additional benefit was observed with a one-off, adjuvant Lf lavage during the initial decontamination of the surgical wound, compared with saline alone, and in combination with the antiseptic Bactisure. This animal model provides the foundation for future antibiofilm therapies

Abstract. Background. Blood transfusion requirement after primary total hip replacements (THR) and total knee replacements (TKR) was found to be related to increased post-operative complications rate and length of hospital stay. Pre-operative haemoglobin level remains the single most important factor determining the requirement for post-operative blood transfusion. Methods. We carried out a local retrospective audit of 977 THRs and TKRs in 2019. Pre-operative and pre-transfusion haemoglobin levels for transfused group of patients were recorded. Results. A total of 977 patients had THRs and TKRs of which 34 (3.5%) had blood transfusions. From the 437 THRs, 24(5.5%) had bloods transfusions of which 19 were female. From the 540 TKRs 10(1.8%) were transfused, 9 were female. The average length of stay (LOS) for those transfused was 6.8 days and the average LOS for our trust is 3.2 days. Conclusion. The incidence of blood transfusion after primary THR or TKR was 3.5% in 2019. The majority of patients who received post-operative blood transfusion were found to have pre-operative haemoglobin level below 12 g/dl representing 61.7% of all the transfused patients. Transfused patients had more than double the average expected length of stay. The incidence of blood transfusion and associated risks can be improved by early detection and proper management of pre-op anaemia. Pre-assessment clinic has got a pivotal role but needs reminding of pre-op haemoglobin management strategies. Pre-operative optimisation of patients using either oral, intravenous iron supplements or erythropoietin according to the blood management protocol by the Royal College of Surgeons

INTRODUCTION. Due to increasing interest into taper corrosion observed primarily in hip arthroplasty devices with modular tapers, efforts towards characterizing the corrosion byproducts are prevalent in the literature [1–4]. As a result of this motivation, several studies postulate cellular induced corrosion due to the presence of remarkable features in the regions near taper junction regions and articulating surfaces [3–5]. Observations made on explanted devices from a retrieval database as well as laboratory tests have led to the alternative proposal of electrocautery-electrosurgery damage as the cause of these features. These surgical instruments are commonly used for hemostasis or different degrees of tissue dissection. METHODS. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to evaluate the features observed on retrieved devices. Retrieved devices consisted of OXINIUM and cobalt-chromium-molybdenum (CoCrMo) femoral implants, a Titanium-alloy hip stem, and a CoCrMo metal-on-metal femoral head. Electrocautery-electrosurgery damage was created using a SurgiStat II (Valleylab, Colorado) onto various components (CoCrMo, OXINIUM femoral heads as well as Ti-6Al-4V and CoCrMo alloy test stem constructs). Test components were evaluated using the same methods as the retrieved devices. RESULTS. Remarkable features were present on retrieved devices (Figure 1) which were similar to previous studies (3–5). The appearance of these features could be described as crater-like, pitted, scratched, molten or splattered material, and ruffled. These features were present on articulating and non-articulating regions as well as near taper junctions. Testing performed on samples using the SurgiStat II, created features that were similar in appearance (Figure 1). Additionally, material transfer that included an iron peak based on EDS in addition to the cobalt and chromium (present due to native material) was detected in the regions of contact (Figure 2). CONCLUSIONS. It was possible to re-create damage features similar to those previously characterized as remarkable features created by cellular-induced corrosion [3–5]. It is theorized that the high-voltage based electrocautery (commonly Bovie) or high-frequency based electrosurgical devices can result in localized degradation/alteration of oxides and passive regions of commonly used orthopaedic alloys. These surgical instruments, specifically the cutting electrodes, are frequently made of stainless steels which can result in iron transfer during contact with the device. During the surgical use of the electrocautery-electrosurgery instrument, it may be necessary to remove tissue, bone, or cauterize near the implant or explant which may have led to the damage features noted in this study and the previous literature [3–5]. If this damage occurs during the initial implantation of the devices, it may further exacerbate corrosion in the damaged region and/or alter the mechanical integrity of the constructs (i.e. fatigue performance)

Introduction. Arthroplasties of hip and knee are associated with blood loss, which may lead to adverse patient outcome. Jehovah's Witnesses do not accept blood transfusion. Performing arthroplasties in Witness patients without transfusion has been a matter of concern. We developed a protocol, which avoids transfusion in arthroplasties of Witness patients, and evaluated the feasibility and safety of the protocol. Materials and Methods. Our protocol consisted of subcutaneous administration of 4000 U recombinant erythropoietin and 100 mg of intravenous iron supplements when patient's hemoglobin level was less than 10 g/dL in preoperative evaluation. During the operation, cell saver, and plasma expander were used. Postoperatively, recombinant erythropoietin was administered three times a week and iron supplements were administered daily until the hemoglobin level reached 10 g/dL. We evaluated the feasibility of our protocol, perioperative complications and hematologic changes. Results. From March 2002 to December 2014, 179 Jehovah's Witness patients(232 cases) visited our department to receive hip or knee arthroplasty. The 225 arthroplasties were successfully performed using the protocol without any transfusion. Thus, the feasibility of our protocol in patients, who refused transfusion, was 97.0%. 46 bilateral patients who received second arthroplasty was excluded for statistical independency. The mean age at the time of surgery was 70.7 years. Total 179 arthroplasties were included in this study. The types of joint arthroplasty included 77 total knee arthroplasties, 69 bipolar hemiarthroplasties of the hip and 33 total hip arthroplasties. The mean hemoglobin level was 12.3 g/dL preoperatively, which decreased to 9.4 g/dL during the first 3 days after the operation. After then, the level gradually recovered and reached to 10.3 g/dL on postoperative day 7. Thus, the mean decrease of hemoglobin level was 2.0 g/dL (16.3%) as of seven days after the operation. One patient had pulmonary embolism. The remaining 179 patients survived the procedure and were discharged from the hospital. Two patients had symptomatic DVT. Two patients (1.1%) died within 90 days after the operation: one due to myocardial infarct and the other due to gastrointestinal bleeding. Periprostheitic joint infection developed in 2 patients (1.1%). Conclusion. Joint arthroplasty could be done without transfusion using the protocol in most of our patients. The hemoglobin level was stable during and after the arthroplasty. We did not find complications related with our protocol. The rates of infection and mortality were similar with known infection and mortality rates of arthroplasties. In patients who do not want allogeneic transfusions, our protocol is a safe alternative to perform joint arthroplasty

Common reasons for higher-than-average cost for a total hip arthroplasty are prolonged patient hospitalisation, which can be caused by among other factors, bleeding complications. The incidence of perioperative anemia has direct costs (blood transfusions), but also numerous indirect costs such as longer hospital stays, poor performance in physical therapy, and the potential for blood-borne infection. The incidence of pre-operative anemia in patients undergoing total hip arthroplasty has been reported to be as high as 44%, while total peri-operative blood loss for total hip arthroplasty may average between 750 and 1,000 mL. Anemia negatively impacts length of stay, patient function during rehabilitation, and patient mortality. Transfusions carry well known risks, including infection and fatal anaphylaxis, which are important factors considering that the transfusion rate has been reported to be as high as 45% and that transfused patients receive, on average, two units of blood. Methods that have been described in the literature include pre-treatment with erythropoietin, pre-operative hemodilution with intra-operative blood salvage, surgical techniques such as gentle soft tissue handling and meticulous hemostasis, bipolar sealers, intravascular occlusion, hemostatic agents, and early removal of drains. Pharmacologic approaches include treatment with erythropoietin, iron and folate. Randomised trials have demonstrated reduction in the risk for transfusion in patients treated with erythropoietin. Several studies have established a once-weekly dosing schedule of 40,000 international units (300–600 IU/kg) to be effective, and synergism has been observed in patients treated in combination with iron (ferrous sulfate, 325 mg three times a day). Patients with hemoglobin values between 10 and 14 g/dL are most likely to benefit. Intra-operatively, antifibrinolytics such as tranexamic acid (10 mg/kg) given as a single dose pre-operatively has been shown to decrease blood loss and the transfusion rate. Hypotensive anesthesia also effectively decreases blood loss without impairing renal function, but is technically demanding. Post-operatively, re-infusion drains may reduce the need for transfusions in total hip and total knee arthroplasty, but cannot be used in cases of infection or malignancy. By minimising peri-operative bleeding and bleeding complications through pre-operative optimisation, intra-operative surgical techniques that minimise blood loss, and post-operative care, patient disposition can be streamlined and delays for patient discharge can be avoided

INTRODUCTION. In recent years, there has been a shift toward outpatient and short-stay protocols for patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). We developed a peri-operative THA and TKA short stay protocol following the Enhance Recovery After Surgery principles (ERAS), aiming at both optimizing patients’ outcomes and reducing the hospital length of stay. The objective of this study was to evaluate the implementation of our ERAS short-stay protocol. We hypothesized that our ERAS THA and TKA short-stay protocol would result in a lower complication rate, shorter hospital length of stay and reduced direct health care costs compared to our standard procedure. METHODS. We compared the complications rated according to Clavien-Dindo scale, hospital length of stay and costs of the episode of care between a prospective cohort of 120 ERAS short-stay THA or TKA and a matched historical control group of 150 THA or TKA. RESULTS. Significantly lower rate of Grade 1 and 2 complications in the ERAS short-stay group compared with the standard group (mean 0.8 vs 3.0, p<0.001). Postoperative complications that were experienced by significantly more patients in the control group included pain (67% vs 13%, p<0.001), nausea (42% vs 12%, p<0.001), vomiting (25% vs 0.9%, p<0.001), dizziness (15% vs 4%, p=0.006), headache (4% vs 0%, p=0.04), constipation (8% vs 0%, p=0.002), hypotension (26% vs 11%, p=0.003), anemia (8% vs 0%, p=0.002), oedema of the operated leg (9% vs 1%, p=0.005), persistent lameness (4% vs 0%, p=0.04), urinary retention (13% vs 4%, p=0.006) and anemia requiring blood or iron transfusion (8% vs 0%, p=0.002). No difference was found between the 2 groups for Grade 3, 4, or 5 complications. The mean hospital length of stay for the ERAS short-stay group decreased by 2.8 days for the THAs (0.1 vs 2.9 days, p bellow 0.001) and 3.9 days for the TKAs (1.0 vs 4.9 days, p<0.001). The mean estimated direct health care costs reduction with the ERAS short-stay protocol was 1489% per THA and 4206% per TKA. DISCUSSION AND CONCLUSION. Shorter hospitalization time after THA and TKA is associated with lower risk of nosocomial infections and adverse events related to reduced mobilization such as venous thromboembolism, pulmonary atelectasis, and constipation. In addition, it increases bed availability in a restricted environment and is very favorable economically for the care provider. Multiple strategies have been described to reduce hospital length of stay. One attractive option is to follow the ERAS principles to improve patient experience to a level where they will feel confident to leave for home earlier. Implementation of a ERAS short-stay protocol for patients undergoing THA or TKA at our institution resulted not only in reduced hospital length of stay, but also in improved patient care and reduced direct health care costs

Acute achilles tendon ruptures are increasing in incidence and occur in 18 per 100 000 people per year, however there remains a lack of consensus on the best treatment of acute ruptures. Randomised studies comparing operative versus non-operative treatment show operative treatment to have a significantly lower re-rupture rate, but these studies have generally used non-weight bearing casts in the non-operative group. Recent series utilizing more aggressive non-operative protocols with early weight-bearing have noted a far lower incidence of re-rupture, with rates approaching those of operative management. Weight bearing casts may also have the advantages of convenience and an earlier return to work, and the purpose of this study was to compare outcomes of traditional casts versus Bohler-iron equipped weight-bearing casts in the treatment of acute Achilles tendon ruptures. 83 patients with acute Achilles tendon ruptures were recruited from three Auckland centres over a 2 year period. Patients were randomised within one week of injury to receive either a weight-bearing cast with a Bohler iron or a traditional non weight-bearing cast. A set treatment protocol was used, with a total cast time of eight weeks. Patients underwent detailed muscle dynamometry testing at 6 months, with further follow up at 1 year and at study completion. Primary outcomes assessed were patient satisfaction, time to return to work, and overall re-rupture rates. Secondary outcomes included return to sports, ankle pain and stiffness, footwear restrictions, and patient satisfaction. There were no significant differences in patient demographics or activity levels prior to treatment. At follow up, 1 patient (2%) in the Bohler iron group and 2 patients (5%) in the non weight bearing group sustained re-ruptures (p=0.62). There was a trend toward an earlier return to work in the weight-bearing group, with 58% versus 43% returning to work within 4 weeks, but the difference was not significant. 63% of patients in the weight bearing group reported freedom from pain at 12 months compared to 51 % in the non weight bearing group. There were no statistically significant differences in Leppilahti scores, patient satisfaction, or return to sports between groups. Weight-bearing casts in the non-operative treatment of Achilles tendon ruptures appear to offer outcomes that are at least equivalent to outcomes of non-weight bearing casts. The overall rerupture rate in this study is low, supporting the continued use of initial non-operative management in the treatment of acute ruptures

Total hip and knee arthroplasty is known to have a significant blood loss averaging 3–4 g/dL. Historically, transfusion rates have been as high as 70%. Despite years of work to optimise blood management, some published data suggests that transfusion rates (especially with allogeneic blood) are rising. There is wide variability between surgeons as well, suggesting that varying protocols can influence transfusion rates. Multiple studies now associate blood transfusions with negative outcomes including increased surgical site infection, costs, and length of stay. Preoperative measures can be employed. Identify patients that are at increased risk of blood transfusion. Smaller stature female patients, have pre-operative anemia (Hgb less than 13.0 gm/dl), or are undergoing revision or bilateral surgery are at high risk. We identify these patients and check a hemoglobin preoperatively, using a non-invasive finger monitor for screening. For anemic patients, iron administration (oral or IV) can be given, along with Procrit/Epogen in select cases. Insurance coverage for that medication has been challenging. Intraoperative measures that have been linked to reduced postoperative transfusions include regional anesthesia and intraoperative hypotension (mean arterial pressure <60mm/hg). Lowering the surgical time by practicing efficient, organised, and quality surgery, along with leaving a dry field at the completion of surgery can reduce blood loss. Tranexemic acid (TXA) is an antifibrinolytic agent that has been shown to be effective, reducing average blood loss by 300 cc per case. There are multiple different administration protocols: IV using either a weight-based dosing 10–20 mg/kg or standardised dosing for all patients. Our current regimen is 1 gm IV preoperatively, 1 gm IV in PACU. Topical TXA can be used, usually 2–3 gm mixed in 50–100 cc of saline, sprayed in wound and allow to soak for 3–5 minutes. Oral administration is attractive for ease of use and reduced cost, standard oral dosing is 1950 mg PO 2 hours prior to surgery. The American Association of Hip and Knee Surgeons, in collaboration with the American Association of Orthopedic Surgeons, American Society of Regional Anesthesiologists, and the Hip & Knee Society have developed a Clinical Practice Guideline with 8 recommendations for TXA as follows: All individual formulations are effective at reducing blood loss – strong; No method of administration is clearly superior at reducing blood loss and the risk of transfusion; The dose of IV or topical TXA does not significantly affect the drug's ability to reduce blood loss and risk of transfusion; Multiple doses of IV or oral TXA compared to a single dose does not significantly alter the risk of blood transfusion; Pre-incision IV TXA administration potentially reduces blood loss and risk of transfusion compared to post-incision administration; Administration of all TXA formulations in patients without history of VTE does not increase the risk of VTE; Administration of all TXA formulations in patients with a history of VTE, MI, CVA, TIA, or vascular stent does not appear to increase the risk of VTE; Administration of all TXA formulations does not appear to increase the risk of arterial thrombotic events; Postoperative measures to reduce transfusion rates include changing transfusion triggers. Instead of treating a “number”, use lower thresholds and employ safe algorithms established. In conclusion, a comprehensive blood management program can reduce transfusion rates to less than 3% for THA and 1% for TKA and facilitate outpatient total joint arthroplasty

Aims

The number of females within the speciality of trauma and orthopaedics (T&O) is increasing. The aim of this study was to identify: 1) current attitudes and behaviours of UK female T&O surgeons towards pregnancy; 2) any barriers faced towards pregnancy with a career in T&O surgery; and 3) areas for improvement.

Blood donation in England is voluntary and a limited resource. Blood transfusion is essential and beneficial in some postoperative hip replacements, however is not without inherent risks. Royal College of Physician audit in 2007 has shown wide variation in transfusion with an average rate of 25% (22% – 97%). Patient blood management is an established approach to optimising need for post- operative transfusion. The Surgical Blood Conservation Service (SBCS) was set up in 2009 to enable a reduction in the demand for blood transfusion during and postoperatively in many orthopaedic procedures. We aimed to achieve preoperative haemoglobin of 12g/dl (males) and 11g/dl (females). Low levels were treated with iron therapy. Surgery was deferred till satisfactory Hb levels were reached. During surgery cell salvage was routinely used. Transfusion was recommended at postoperative Hb < 8g/dl. The transfusion rate was estimated at 47% in 2002. Following the introduction of SCBS, the transfusion rate reduced considerably to 7.9% in 2009 with a further reduction to 7.29% in 2011 and 3.16% in 2012. In 2013, 10 out of 442 hip replacements received transfusion (2.21%). Our results demonstrate successful Patient blood management, minimising the need for post- operative transfusion

We studied twelve parameters (physical appearance, mucin clot, fibrin clot, white cell count, differential count, red blood cell count, gram stain for bacteria, crystal microscopy, aerobic bacterial culture, anaerobic bacterial culture and ratio between synovial sugar and blood sugar) in over 300 samples of synovial fluid from patients with a variety of suspected pathologies (e.g. infection, inflammatory disease, infection adjacent to a joint, aseptic loosening of a prosthesis). The diagnosis of infection was further established using clinical signs, radiological features, full blood count, C-reactive protein and iron profile. Many of the patients came to surgery. This of course created further opportunity to establish or rule out the diagnosis of infection with greater certainty. Nine of the features of synovial fluid were analysed statistically, including turbidity, diminished viscosity, mucin clot, fibrin clot, total white cell count, polymorphs greater than 60%, bacteria observed on direct microscopy, bacteria yielded by culture and concentration of synovial sugar less than 40% of the simultaneous blood sugar. The positive or negative features of infection were determined to be true or false in the light of the cumulative overall features of infection. The data so obtained was analysed to establish sensitivity, specificity, positive predictive value, negative predictive value and accuracy. The mass of data so obtained cannot be meaningfully expressed in such a brief abstract. Important examples are when culturing synovial fluid there were 44% false negatives or no growth and 56% true positives. Looking at the ratio between synovial sugar and blood sugar we found that taking 40% as the critical value, this was 62% sensitive, the specificity was 89%, the accuracy was 73%, the positive predictive value was 89%, the negative predictive value was 62.4%. However we went further and separated those who were definitely infected or probably infected i.e. Groups 4 & 5 from those who were probably or definitely NOT infected according to the sum of clinical laboratory and radiological parameters. When thus separated the predictive value of a positive result was 100% in Group 4 & 5 and 0% in Group 1 & 2. The predictive value of a negative result in Group 1 & 2 was 98.7% accurate and 22.4% in Group 4 & 5

Introduction. Dual modular hip prostheses were introduced to optimize the individual and intra-surgical adaptation of the implant design to the native anatomics und biomechanics of the hip. The downside of a modular implant design with an additional modular interface is the potential susceptibility to fretting, crevice corrosion and wear [1–2]. The purpose of this study was to characterize the metal ion release of a modular hip implant system with different modular junctions and material combinations in consideration of the corrosive physiological environment. Methods. One design of a dual modular hip prosthesis (Ti6Al4V, Metha®, Aesculap AG, Germany) with a high offset neck adapter (CoCrMo, CCD-angle of 130°, neutral antetorsion) and a monobloc prosthesis (stem size 4) of the same implant type were used to characterize the metal ion release of modular and non-modular hip implants. Stems were embedded in PMMA with 10° adduction and 9° flexion according to ISO 7206-6 and assembled with ceramic (Biolox® delta) or CoCrMo femoral heads (XL-offset) by three light impacts with a hammer. All implant options were tested in four different test fluids: Ringer's solution, bovine calf serum and iron chloride solution (FeCl3-concentration: 10 g/L and 114 g/L). Cyclic axial sinusoidal compressive load (Fmax = 3800 N, peak load level of walking based on in vivo force measurements [3]) was applied for 10 million cycles using a servohydraulic testing machine (MTS MiniBionix 370). The test frequency was continuously varied between 15 Hz (9900 cycles) followed by 1 Hz (100 cycles). The metal ion concentration (cobalt, chromium and titanium) of the test fluids were analysed using ICP-OES and ICP-MS at intervals of 0, 5·105, 2·106 and 10·106 cycles (measuring sensitivity < 1 µg/L). Results. Due to the additional modular interface between stem and neck adapter the total metal ion release of the modular hip endoprosthesis system increased significantly and is comparable to the coupling of a monobloc stem and a CoCrMo femoral head (Fig. 1). The application of ceramic femoral heads reduced the total cobalt and chromium release in the stem-head taper interface of non-modular and modular stems. In comparison between the four test fluids could be observed that lower pH-values and higher FeCl3-concentrations increased the metal ion release (Fig 2). In contrast, the use of bovine calf serum decreased the metal ion release of modular junctions due to the presence of proteins and other organic components. Discussion. For testing hip implants with proximal femoral modularity according to ISO and ASTM standards, sodium chloride solutions are frequently used to determine the fatigue strength and durability of the stem-neck connection. The present study illustrate that the expansion of standard requirements of biomechanical testing and the use of alternative test fluids is necessary to simulate metal ion release by electro-chemical processes. A promising approach is the use of adapted iron-chloride solutions (10 g/L FeCl3, pH 2) to evaluate the susceptibility of modular hip junctions to fretting, crevice and contact corrosion

Aims

Tuberculosis (TB) is one of the biggest communicable causes of mortality worldwide. While incidence in the UK has continued to fall since 2011, Bradford retains one of the highest TB rates in the UK. This study aims to examine the local disease burden of musculoskeletal (MSK) TB, by analyzing common presenting factors within the famously diverse population of Bradford.

Introduction. The possibility of corrosion at the taper junction of hip replacements was initially identified as a concern of generating adverse reactions in the late 1980s. Common clinical findings of failure are pain, clicking, swelling, fluid collections, soft tissue masses, and gluteal muscle necrosis identified intra operatively. Methodology. The joint replacement surgery was performed utilizing a posterior approach to the hip joint. The data from all surgical, clinical and radiological examinations was prospectively collected and stored in a database. Patients were separated into two groups based on bearing material, where group 1 had a CoC bearing and ABG modular stem whilst group 2 had a MoM bearing and SROM stem, with each group having 13 cases. Pre-operative revision surgery and post-operative blood serum metal ion levels we collected. Cup inclination and anteversion was measured using the Ein-Bild-Roentgen-Analyse (EBRA) software. A range of 2–5 tissue sections was examined per case. 2 independent observers that were blinded to the clinical patient findings scored all cases. The tissue grading for the H&E tissue sections were graded based on the presence of fibrin exudates, necrosis, inflammatory cells, metallic deposits, and corrosion products. The corrosion products were identified into 3 groups based on visible observation and graded based on abundance. A scanning electron microscope (SEM) Hitachi S3400 was used to allow for topographic and compositional surface imaging. Unstained tissue sections were used for imaging and elemental analysis. X-Ray diffraction was the analytical technique used for the taper debris that provided identification on the atomic and molecular structure of a crystal. Result. Group 1 patients showed a significant reduction (p = 0.0002) in the Co, however the decrease of Cr ion concentration had no statistical significance (p = 0.48). The Co (p = 0.001) and Cr (p = 0.02) levels significantly reduced after revision surgery for patients within group 2. The largest differences in the abundance between the two groups were for the brown/red corrosion particles where group 2 is highly significant (p<0.001) compared to group 1. The specific identification was determined using a mapping technique that showed the red/brown colour consisted of evenly scattered Ti (green) and Cr (red) particles (figure 1). Elemental analysis of the green shards showed chromium as a major metallic element with traces of cobalt (figure 2). The ABG modular collected debris matched the peaks of the following crystaline strucutes: chromium oxide (CrO), titantium oxide (TiO2), and chromium oxide (Cr2O3), and iron titanium oxide (Fe2Ti3O9) (figure 2). The peaks from the XRD scan were assessed against these possible elements which showed the most were aluminium nitride and chromium oxide (Cr2O3). Both implant configurations produced an ALTR response indicative from the tissue sections graded and visually observed. Conclusion. This study has characterized the corrosion products produced at taper junctions. The histology presented with similar results across the two groups suggestive that due to the same corrosion products found between both groups this was expected

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Background. One-stage bilateral total hip arthroplasty (THA) is twice as invasive as unilateral THA. Therefore, increases in bleeding, postoperative anemia, and complications are a concern. The purpose of this study was to investigate hemoglobin values and the use of autologous and allogenic blood transfusion after one-stage bilateral THA. Methods. Twenty-nine patients (7 men and 22 women; 58 hips) were treated with one-stage bilateral THA. The mean age of subjects at the time of surgery was 60.6 years. The average body mass index for patients was 21.7 kg/m. 2. The diagnoses were secondary osteoarthritis due to developmental dysplasia of the hip (n=25) and avascular necrosis (n=4). All patients had donated 800 ml of autologous blood in 2 stages preoperatively (1 to 4 weeks apart). All patients took iron supplements starting from 5 weeks preoperatively. For all patients, the procedure was performed under general anesthesia in the lateral decubitus position via a posterolateral approach. Intra-operative blood salvage was not used. Suction drains were inserted subfascially. As a general rule, pre-donated autologous blood was transfused back to the patients intra- or post-operatively. Allogenic blood transfusion was performed when clinical symptoms of anemia occurred (hypotension, low urinary output, tachycardia, etc.) rather than using a preset blood threshold (hemoglobin level <8 g/dl). To determine changes in blood pressure following surgery until the next morning, systolic and diastolic blood pressure were measured at 3-hr intervals. Results. The mean duration of surgery was 67.4 min for the procedure on the side that was operated on first, 32.7 min to change to the other side, and 68.4 min for the procedure on the other side. The mean blood loss was 576.1 ml. Hemoglobin values at baseline, at the time of autologous blood donation, and on the first day after surgery were 13.2, 12.7, and 8.7 g/dl respectively. Hemoglobin values were significantly different between the 2 weeks before surgery and the first day after surgery. Systolic and diastolic blood pressure were the lowest 3–6 hrs postoperatively (mean, 86/55). Blood reinfusion using autologous blood was performed for all patients. The allogenic blood transfusion rate was 25.0% (range, 2–8 units). In terms of complications, one patient developed an arrhythmia on postoperative day 5. This was the patient for whom autologous blood donation could not be performed due to pre-existing anemia. This patient also had right-sided sciatic nerve palsy. Discussion. With respect to one-stage bilateral THA, Gie showed that allogenic blood transfusion rate with or without autologous blood donation was 42% and 87% respectively. The allogenic blood transfusion rate was 25.0% in our study. Establishing a procedure to perform surgery in a shorter time period may further reduce the rate of allogenic blood transfusion. Although not used herein, intraoperative blood salvage may also be considered. Conclusions. In one-stage bilateral THA, autologous blood donation is effective in managing perioperative anemia and reducing the rate of allogenic blood transfusion. Perioperative blood management based on individual patients' situations are important for the safe performance of one-stage bilateral THA

Introduction. Sir John Charnley introduced his concept of low friction arthroplasty— though this did not necessarily mean low wear, as the initial experience with metal on teflon proved. Although other bearing surfaces had been tried in the past, the success of the Charnley THR meant that metal-on-polyethylene became the standard bearing couple for many years. However, concerns regarding the occurrence of peri-prosthetic lysis secondary to wear particles lead to consideration of other bearing surfaces and even to the avoidance of cement (although this has proven to be erroneous). Bearing combinations include polymers, ceramic and metallic materials and are generally categorised as hard/soft or hard/hard. In general, all newer bearing surface combinations have reduced wear but present with their own strengths and weaknesses, some of which are becoming more apparent with time. Bearing surfaces must have the following characteristics: low wear rate, low friction, Biocompatibility and corrosion resistance in synovial fluid. Hard/soft. Femoral head components are generally made of cobalt, chromium alloy, either cast or forged. Both alumina and zirconia ceramics have been used as femoral head materials and the hardness is thought to reduce the incidence of surface damage to the femoral head. The hard femoral heads have been traditionally matched with conventional ultra high molecular weight polyethylene. (UHMWPE) which has been produced by either ram extrusion or compression moulding. Over the past 10 years, most implant companies have moved to highly cross-linked UHMWP which in both laboratory and human RCTs have shown appreciably less wear. Hard/hard bearings – Metal-on-metal (M-O-M). The first generation of metal bearings were based on stainless steel couples but the metal on metal design by. McKee-Farrar was made from CoCrMo alloy with large head diameters. The second generation M-O-M bearing were introduced by Weber using wrought. CoCrMo alloy with low surface roughness and wear rates about 100 to 200 times less than traditional metal/UHMWPE. The re-introduction of resurfacing hip arthroplasty has been made possible by the improvement in metal technology. Concerns however exist with the long term biologic effects of metal ions, the reported incidence of sensitivity reactions to metal and the more demanding techniques required for implantation. Ceramic on Ceramic (C-O-C). Alumina ceramic bearing surfaces are extremely hard, have high wear resistance and reported low concentration of wear particles in peri-prosthetic tissues. Unlike M-O-M there is no ion release. While the reported fracture rate for ceramic couplings is extremely low their proper implantation is important to minimise impingement. There is an incidence of squeaking not seen in other bearing couples and because of the hardness of the bearing, long term concerns with stress shielding of bone remain. Clinical outcomes. Data will be presented from the Australian Orthopaedic. Association National Joint Replacement Registry on clinical outcomes of bearing surfaces. Overall metal on UHMWPE has the least revision of any bearing surface couple used with conventional hip replacement. Future trends. Further research into hard/soft bearings will look at ways to reduce UHMWPE wear without compromise of clinical results based on over 40 years use. Hard-on-hard bearings may focus on combining the best features of both. M-O-M and C-O-C couplings without fracture risk or metal iron release. When deciding which bearing surface is suitable for your patients it must be emphasised that wear reduction is only one of several considerations when taking into account the most appropriate implant

Aims

The aim of this study was to determine the impact of the severity of anaemia on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA).