Aims. Transfusion after primary total hip arthroplasty (THA) has become rare, and identification of causative factors allows preventive measures. The aim of this study was to determine patient-specific factors that increase the risk of needing a blood transfusion. Methods. All patients who underwent elective THA were analyzed retrospectively in this single-centre study from 2020 to 2021. A total of 2,892 patients were included. Transfusion-related parameters were evaluated. A multiple logistic regression was performed to determine whether age, BMI, American Society of Anesthesiologists (ASA) grade, sex, or preoperative haemoglobin (Hb) could predict the need for transfusion within the examined patient population. Results. The overall transfusion rate was 1.2%. Compared to the group of patients without blood transfusion, the transfused group was on average older (aged 73.8 years (SD 9.7) vs 68.6 years (SD 10.1); p = 0.020) and was mostly female (p = 0.003), but showed no significant differences in terms of BMI (28.3 kg/m. 2. (SD 5.9) vs 28.7 kg/m. 2. (SD 5.2); p = 0.720) or ASA grade (2.2 (SD 0.5) vs 2.1 (SD 0.4); p = 0.378). The regression model identified a cutoff Hb level of < 7.6 mmol/l (< 12.2 g/dl), aged > 73 years, and a BMI of 35.4 kg/m² or higher as the three most reliable predictors associated with postoperative transfusion in THA. Conclusion. The possibility of transfusion is predictable based on preoperatively available parameters. The proposed thresholds for preoperative Hb level, age, and BMI can help identify patients and take preventive measures if necessary. Cite this article: Bone Jt Open 2024;5(7):560–564

Bone tissue engineering attempts at substituting critical size bone defects with scaffolds that can be primed with osteogenic cells, usually mesenchymal stem cells (MSC) from the bone marrow. Although overlooked, peripheral blood is a valuable source of MSC and circulating osteoprogenitors (COP), bearing a significant regenerative potential, and peripheral blood is easier to access than bone marrow. We thus studied osteodifferentiation of peripheral blood mononuclear cells (pbMNC) under different culture conditions, and how they compared to primary human osteoblasts. pbMNC were isolated from healthy adult volunteers by Ficoll density gradient centrifugation, and they were then cultured using media supplemented with 100nM Dexamethasone, 10mM sodium β-glycero phosphate and ascorbic acid (either 40mM or 0.05mM). For comparison, primary osteoblasts were isolated from the femoral heads of patients undergoing hip arthroplasty. After 4 weeks of culture, osteogenic activation was quantified with spectrometric measurement of alkalic phosphatase (ALP) and lactate dehydrogenase (LDH) levels. The extent of osteoid mineralization was measured with Alizarin red staining. We studied the effects of 1) varying cell concentration at seeding, 2) surface coating of culture wells with collagen and 3) high compared to low ascorbic acid (40mM and 0.05mM) media. Higher numbers of pbMNC (0.5–5.9 versus 0.062–0.25 million cells per well) at seeding resulted in a lower ALP/LDH-ratio (mean ± standard deviation), 0.39 ± 0.33 arbitrary units (AU) versus 1.36 ± 1.06 AU, but led to higher amount of osteoid production, 0.10 ± 0.06 versus 0.065 ± 0.02 AU, p < 0.05. Culture of pbMNC on collagen did not confer any difference in ALP/LDH-ratios, with 0.43 ± 0.3 AU for collagen-coated and 0.43 ± 0.41 AU for uncoated wells (p = 0.95), and we also observed no relevant difference in osteoid production (0.07 ± 0.01 AU for collagen-coated versus 0.1 ± 0.08 AU for uncoated wells, p = 0.28). Cultures of pbMNC on collagen in media supplemented with a higher concentration of ascorbic acid showed a 130% higher ALP/LDH-ratio when compared to cultures exposed to a lower ascorbic acid concentration (p < 0.05). Cultures with a low initial concentration of pbMNC (0.5 − 1 million cells) had no significantly different ALP/LDH-ratio when compared to primary human osteoblasts, but the cultures of pbMNC resulted in a 90% increase in osteoid mineralization when compared to primary human osteoblasts (p < 0.05). These findings indicate that progenitor cells derived from peripheral blood have a significant osteogenic potential, rendering them interesting candidates for seeding of scaffolds intended to fill critical sized bone defects. pbMNC produced almost double the amount of osteoid as primary osteoblasts. The isolation of pbMSC and COP is non-invasive and easy, and they might be seeded directly onto scaffolds without prior ex-vivo expansion, a question that we intend to pursue further

AIM. Retrospective study comparing the effectiveness of preoperative autologous blood donation versus intra-operative blood saver systems in minimizing the need for allogeneic blood transfusion in scoliosis surgery. MATERIALS – METHODS. Between 2003–2009, 37 of the patients (4–33, mean age 20y) who underwent scoliosis surgery, were divided in two groups. The first group (20 patients, mean age 18.7y) underwent autologous blood predonation, prerequisities were body weight over 50 kgr and Hgb above 11 mg/dl. The second group (17 patients, mean age 21.5y) consisted of patients who did not meet the above prerequisities and blood saver was used intra-operatively. Duration of surgery and perioperative Haemoglobulin (Hgb) levels were recorded in both groups. RESULTS. In group A an average of 4 autologous blood units per patient were predonated (3–5 units/patient) and the mean transfusion rate was 3.4 autologous blood units/patient. Only one patient was transfused with one allogeneic blood unit while of the 81 predeposited autologous blood units 15 were wasted (18.5%). In Group B intra-operative autotransfusion systems salvaged 302.9 ml/patient (150–500 ml/patient) while the mean transfusion rate was 2.1 allogeneic blood units/patient. CONCLUSIONS. The use of intra-operative autotransfusion systems seems to reduce the need for allogeneic blood transfusion when compared with preoperative autologous blood donation. However, the lower preoperative Hgb in Group B have to be taken under consideration. Further studies need to prove the effectiveness of these methods so that perioperative blood management minimizes the need for allogeneic blood transfusion in scoliosis surgery

Aims. The diagnosis of periprosthetic joint infection (PJI) can be challenging as the symptoms are similar to other conditions, and the markers used for diagnosis have limited sensitivity and specificity. Recent research has suggested using blood cell ratios, such as platelet-to-volume ratio (PVR) and platelet-to-lymphocyte ratio (PLR), to improve diagnostic accuracy. The aim of the study was to further validate the effectiveness of PVR and PLR in diagnosing PJI. Methods. A retrospective review was conducted to assess the accuracy of different marker combinations for diagnosing chronic PJI. A total of 573 patients were included in the study, of which 124 knees and 122 hips had a diagnosis of chronic PJI. Complete blood count and synovial fluid analysis were collected. Recently published blood cell ratio cut-off points were applied to receiver operating characteristic curves for all markers and combinations. The area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated. Results. The results of the analysis showed that the combination of ESR, CRP, synovial white blood cell count (Syn. WBC), and polymorphonuclear neutrophil percentage (PMN%) with PVR had the highest AUC of 0.99 for knees, with sensitivity of 97.73% and specificity of 100%. Similarly, for hips, this combination had an AUC of 0.98, sensitivity of 96.15%, and specificity of 100.00%. Conclusion. This study supports the use of PVR calculated from readily available complete blood counts, combined with established markers, to improve the accuracy in diagnosing chronic PJI in both total hip and knee arthroplasties. Cite this article: Bone Jt Open 2023;4(11):881–888

The management of autologous blood aims at reducing the need for allogenic transfusion. Blood requirement (autologous and/or allogenic) will depend on the pre-operative red blood cell stock and on the perioperative blood loss. The red cell stock is related to body weight and preoperative haemoglobin (haematocrit) level; it can be calculated accurately, whereas the perioperative blood loss (external and occult) is variable and unpredictable. Preoperative donation of autologous blood, as well as intraoperative and/or postoperative recuperation and reinfusion of shed blood decrease the risk for allogenic transfusion in total hip replacement (THR) and total knee replacement (TKR) surgery. However, their efficiency and cost effectiveness are not optimal when applied to unselected patients. Up to 50% of the predonated units of autologous blood are wasted after THR and THK surgery if patients have not been specifically selected to predonate blood. In hip surgery the volume reinfused after intraoperative blood recuperation obviously depends on intraoperative bleeding; it averages 500 ml in a hip revision operation. In TKR (with a tourniquet) the volume reinfused after postoperative recuperation depends on the amount of blood drained in the immediate postoperative period, which reflects both the amount of bleeding and the efficiency of the drainage. On average, 500 ml of shed blood with a haematocrit of 35% is reinfused, which increases the haemoglobin level by 1.0 gr/dl on average. The efficiency of this technique is unpredictable, with a wide dispersion of individual values (standard deviation: 208 ml) for the volumes reinfused. However, in patients with a body weight of 70 kg or less, the increase in haemoglobin level was more predictable and averaged 1.23 gr/dl. In order to improve the efficiency of these two techniques (preoperative autologous blood donation and recuperation/reinfusion of shed blood), patients need to be targeted, taking into account:. - the calculated preoperative (day before surgery) red blood cell stock and the number of units of predonated blood,. - the lowest postoperative haemoglobin and haematocrit level clinically tolerable for that specific patient,. - the expected perioperative blood loss, which depends on such factors as duration of surgery, anticoagulant administration, use of a tourniquet,etc). As a general rule, a haemoglobin level < 13 gr/dl, age > 65 years and weight < 70 kg all increase the risk to require autologous or allogenic blood transfusion, and would justify planning predonation of blood and/or recuperation/reinfusion of shed blood

Abstract. Introduction. Multiple strategies, used either in isolation or combination, are available to reduce the need for post-operative blood transfusion in joint replacements. Amongst them, the use of tranexamic acid (TXA) has been rising and this study was conducted to compare the efficacy of topical and intravenous TXA in bilateral total knee replacement patients. Materials and methods. Randomised prospective study with 120 patients (male: female: 25:95) undergoing bilateral TKA. Patients were divided into two groups A and B after computer randomization, who received intravenous or topical (intra-articular) TXA respectively. Results. The average haemoglobin loss in intravenous group was 90.2379 g/L as compared to 39.137 g/L in topical group (p < 0.005). Moreover, there was reduction in blood loss in topical (330.1602 ml) as compared to intravenous group (764.9622 ml). The blood transfusion rate was more for the intravenous group (average 1.73 units) than for the topical group (average 0.75, unit). WOMAC score at 6 weeks in the intravenous group was 12.50, and in the topical group was 7.23 (p value < 0.001). Conclusion. Topical TXA is better than intravenous TXA for reduction of blood loss, which also reduces the need for blood transfusion in bilateral TKA patients

Aims. To assess the alterations in cell-specific DNA methylation associated with chondroitin sulphate response using peripheral blood collected from Kashin-Beck disease (KBD) patients before initiation of chondroitin sulphate treatment. Methods. Peripheral blood samples were collected from KBD patients at baseline of chondroitin sulphate treatment. Methylation profiles were generated using reduced representation bisulphite sequencing (RRBS) from peripheral blood. Differentially methylated regions (DMRs) were identified using MethylKit, while DMR-related genes were defined as those annotated to the gene body or 2.2-kilobase upstream regions of DMRs. Selected DMR-related genes were further validated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) to assess expression levels. Tensor composition analysis was performed to identify cell-specific differential DNA methylation from bulk tissue. Results. This study revealed 21,060 hypermethylated and 44,472 hypomethylated DMRs, and 13,194 hypermethylated and 22,448 hypomethylated CpG islands for differential global methylation for chondroitin sulphate treatment response. A total of 12,666 DMR-related genes containing DMRs were identified in their promoter regions, such as CHL1 (false discovery rate (FDR) = 2.11 × 10. -11. ), RIC8A (FDR = 7.05 × 10. -4. ), and SOX12 (FDR = 1.43 × 10. -3. ). Additionally, RIC8A and CHL1 were hypermethylated in responders, while SOX12 was hypomethylated in responders, all showing decreased gene expression. The patterns of cell-specific differential global methylation associated with chondroitin sulphate response were observed. Specifically, we found that DMRs located in TESPA1 and ATP11A exhibited differential DNA methylation between responders and non-responders in granulocytes, monocytes, and B cells. Conclusion. Our study identified cell-specific changes in DNA methylation associated with chondroitin sulphate response in KBD patients. Cite this article: Bone Joint Res 2024;13(5):237–246

Elevated blood cobalt secondary to metal-on-metal (MoM) hip arthroplasties has been shown to be a risk factor for developing cardiovascular complications including cardiomyopathy. Published case reports document cardiomyopathy in patients with blood cobalt levels as low as 13µg/l (13ppb, 221nmol/l). Clinical studies have found conflicting evidence of cobalt-induced cardiomyopathy in patients with MoM hips. Global longitudinal strain (GLS) is an echocardiography measurement known to be more sensitive than ejection fraction at diagnosing early cardiomyopathies. The extent of cardiovascular injury, as measured by GLS, in patients with elevated blood cobalt levels has not previously been examined. Sixteen patients with documented blood cobalt ion levels above 13µg/l were identified from a regional arthroplasty database. They were matched with eight patients awaiting hip arthroplasty with no history of cobalt implants. All patients underwent electrocardiogram and echocardiogram assessment for signs of cardiomyopathy including GLS. Patients with MoM hip arthroplasties had a mean blood cobalt level of 29µg/l (495nmol/l) compared to 0.01µg/l (0.2nmol/l) in the control group. There was no difference or correlation in ejection fraction (EF), left ventricular (LV) end systolic dimension, LV end diastolic dimension, fractional shortening, ventricular wall thickness or E/e’ ratio. However, GLS was significantly reduced in patients with MoM hip arthroplasties compared to those without (−15.2% v −18%, (MoM v control) p= 0.0125). Pearson correlation demonstrated that GLS is significantly correlated with blood cobalt level (r= 0.8742, p=0.0009). For the first time, this study has demonstrated reduced cardiac function in the presence of normal EF as assessed by GLS in patients with elevated cobalt above 13µg/l. As GLS is a more sensitive measure of systolic function than EF, routine echocardiogram assessment including GLS should be performed in all patients with MoM hip arthroplasties and elevated blood cobalt above 13µg/l. Further work is recommended to assess if these cardiac changes are present in patients with elevated blood cobalt levels below 13µg/l

Elevated blood cobalt secondary to metal-on-metal (MoM) hip arthroplasties has been shown to be a risk factor for developing cardiovascular complications including cardiomyopathy. Published case reports document cardiomyopathy in patients with blood cobalt levels as low as 13µg/l. Clinical studies have found conflicting evidence of cobalt-induced cardiomyopathy in patients with MoM hips. The extent of cardiovascular injury, measured by global longitudinal strain (GLS), in patients with elevated blood cobalt levels has not previously been examined. Sixteen patients with prospectively collected blood cobalt ion levels above 13µg/l were identified and matched with eight patients awaiting hip arthroplasty with no history of cobalt implants. Patients underwent echocardiogram assessment including GLS. Patients with MoM hip arthroplasties had a mean blood cobalt level of 29µg/l compared to 0.01µg/l in the control group. There was no difference or correlation in EF, left ventricular (LV) end systolic dimension, LV end diastolic dimension, fractional shortening, ventricular wall thickness or E/e’ ratio. However, GLS was significantly reduced in patients with MoM hip arthroplasties compared to those without (−15.2% v −18%, (MoM v control) p= 0.0125). Pearson correlation demonstrated that GLS is significantly correlated with blood cobalt level (r= 0.8742, p=0.0009). For the first time, this study has demonstrated reduced cardiac function in the presence of normal EF as assessed by GLS in patients with elevated cobalt above 13µg/l. As GLS is a more sensitive measure of systolic function than EF, routine echocardiogram assessment including GLS should be performed in all patients with MoM hip arthroplasties and elevated blood cobalt

Aims. While preoperative bloodwork is routinely ordered, its value in determining which patients are at risk of postoperative readmission following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is unclear. The objective of this study was to determine which routinely ordered preoperative blood markers have the strongest association with acute hospital readmission for patients undergoing elective TKA and THA. Methods. Two population-based retrospective cohorts were assembled for all adult primary elective TKA (n = 137,969) and THA (n = 78,532) patients between 2011 to 2018 across 678 North American hospitals using the American College of Surgeons National Quality Improvement Programme (ACS-NSQIP) registry. Six routinely ordered preoperative blood markers - albumin, haematocrit, platelet count, white blood cell count (WBC), estimated glomerular filtration rate (eGFR), and sodium level - were queried. The association between preoperative blood marker values and all-cause readmission within 30 days of surgery was compared using univariable analysis and multivariable logistic regression adjusted for relevant patient and treatment factors. Results. The mean TKA age was 66.6 years (SD 9.6) with 62% being females (n = 85,163/137,969), while in the THA cohort the mean age was 64.7 years (SD 11.4) with 54% being female (n = 42,637/78,532). In both cohorts, preoperative hypoalbuminemia (< 35 g/l) was associated with a 1.5- and 1.8-times increased odds of 30-day readmission following TKA and THA, respectively. In TKA patients, decreased eGFR demonstrated the strongest association with acute readmission with a standardized odds ratio of 0.75 per two standard deviations increase (p < 0.0001). Conclusion. In this population level cohort analysis of arthroplasty patients, low albumin demonstrated the strongest association with acute readmission in comparison to five other commonly ordered preoperative blood markers. Identification and optimization of preoperative hypoalbuminemia could help healthcare providers recognize and address at-risk patients undergoing TKA and THA. This is the most comprehensive and rigorous examination of the association between preoperative blood markers and readmission for TKA and THA patients to date. Cite this article: Bone Jt Open 2021;2(6):388–396

Aim. Differentiation of infected (INF) nonunion from aseptic (AS) nonunion is crucial for the choice of intra- and postoperative treatment. Preoperative diagnosis of infected nonunion is challenging, especially in case of low-grade infection lacking clinical signs of infection. Standard blood markers such as C-reactive protein or leucocyte count do not aid in preoperative diagnosis. Proteomic profiling has shown promising results for differentiation of numerous chronic disease states, and in this study was applied to preoperative blood samples of patients with nonunion in an attempt to identify potential biomarkers. Method. This prospective multicenter study enrolled patients undergoing revision surgery of femur or tibia nonunion. Patients with implant removal after regular fracture healing (HEAL) were included as a control-group. Preoperative blood samples, intraoperative tissue samples, sonication of osteosynthesis material and 1-year-follow-up questionnaire were taken. Nonunion patients were grouped into INF or AS after assessing bacterial culture and histopathology of retrieved samples. Diagnosis of infection followed the fracture related infection consensus group criteria, with additional consideration of healing one year after revision surgery. Targeted proteomics was used to investigate a predefined panel of 45 cytokines in preoperative blood samples. Statistical differences were calculated with Kruskal Wallis and Dunn's post hoc test. Cytokines with less than 80% of samples being above the lower limit of detection range (LLDR) were excluded for this study. Results. We recruited 62 AS, 43 INF and 32 HEAL patients. Patients in the two nonunion groups (INF and AS) did not differ concerning smoking, diabetes or initial open or closed fracture. Thirty-two cytokines were above LLDR in >80% of patients. INF patients showed a significant difference in expression of 8 cytokines compared to AS, with greatest differences observed for Macrophage Colony Stimulating Factor 1 (MCSF-1) and Hepatocyte Growth Factor (HGF) (p<0.01). In comparing AS with HEAL patients, 9 cytokines displayed significant differences, including interleukin (IL)-6, Vascular Endothelial Growth Factor A (VEGFA), Matrix Metalloproteinase 1 (MMP-1). Comparison of INF with HEAL patients revealed significantly different expression of 20 cytokines, including. IL-6, IL-18, VEGFA or MMP-1. Conclusions. Our study revealed differences in plasma cytokine profile of blood samples from INF and AS patients. Although no single biomarker is sufficient to differentiate these patients preoperatively in isolation, future multivariant analysis of this cytokine data in combination with clinical characteristics may provide valuable diagnostic insights. Funded by German Social Accident Insurance (FF-FR 0276) and AO Trauma (AR2021_04)

Background and goal of study: Although a great percentage of the total postoperative bleeding corresponds to a hidden blood loss in the tissues and joint, visible blood from the drainage is considered the gold standard for monitoring blood loss after a knee arthroplasty. Only one study was not able to find a consistent relationship between the total blood loss and postoperative drained blood. The aim of our study was to assess the usefulness of a postoperative drainage as a monitor of bleeding following a knee arthroplasty. Material and methods: Fifty patients undergoing unilateral arthroplasty from March to November 2004, were prospectively followed until the fourth postoperative day. Drained red blood cells(RBC) loss was assessed by multiplying the drained blood volume by an haematocrit (Hct) of 30% from a pilot study. Total RBC loss and hidden RBC loss from each patient were calculated. Regression analysis was performed to assess the relationship between the total RBC loss and drained RBC loss. Results and discussions: The average age of the fifty ASA 2 patients was 72 +− 7 years. Nearly all the procedures were performed under intradural anaesthesia. Cemented technique and tourniquet were used in all cases. The mean total RBC loss was 615 +−197ml. The mean drained RBC loss was 206+− 113ml, and mean hidden RBC loss was 414 +−194ml. Thus the hidden loss was 67% of the total blood loss. Regression analysis shown a poor correlation coefficient between the total RBC loss and drained RBC loss (r= 0.31, p< 0.03)

Introduction: Blood conservation has rapidly moved into political and medical agendas. The ongoing shortage of blood in blood banks and the discovery of vCJD pose a threat to UK blood supply with ever rising costs. The use of blood conservation techniques is increasingly being used in surgery to help reduce the need for homologous blood. We studied the use of Autologous blood transfusion drains (Bellovac ABT) in lower limb arthroplasty compared with standard closed suction drains. We studied 123 lower limb arthroplasty (61 TKR & 62 THR) to see if there was a significant reduction in the need for homologous blood transfusion when using re-transfusion drains and its cost effectiveness. Methods: Retrospective analysis of 123 patients undergone lower limb arthroplasty from March 2002 to Dec 2004 under one surgeon using the same technique for TKR and THR. 61 TKR (30 ABT drains v 31 standard drain) and 62 THR (30 ABT drains v 32 standard drain). Data was collected on sex, age, pre & post op Hb, volumes drained, volumes re-transfused and the number of homologous blood transfusions. Results: 30 THR with ABT drains: 14 male, 16 female, mean age 68.7, mean pre op Hb 13.67, mean post op Hb 10.55,mean volume re-transfused 324ml, mean volume drained 466ml. 7 patients(23%) required additional homologous blood transfusion. 32 THR with standard drains: 14 male, 18 female, mean age 68.4, mean pre op Hb 12.96, mean post op Hb 9.36, mean volume drained 579.5ml. 24 patients (75%) required homologous blood transfusion. 30 TKR with ABT drains: 14 male, 16 female, mean age 69.8, mean pre-op Hb13.4, mean post-op Hb 11.03, mean volume re-transfused 415ml, mean volume drained 580ml. 4 patients (13%) required additional homologous blood transfusion. 31 TKR with Standard drains: 13 male, 18 female. Mean age72.1, mean pre-op Hb13.33, mean post-op Hb10.4, mean volume drained 711.5ml. 14 patients (45%) required homologous blood transfusion. No re-transfusion complications occurred in the ABT group. 2 patients requiring homologous blood had increasing pyrexia and transfusion hence stopped. Discussion: 11 out of 60 patients (18%) using ABT drains required additional homologous blood compared with 38 out of 63 patients (60%) requiring homologous blood using standard drains. Pvalue< 0.001. We show a stastically significant reduction in the need for homologous blood transfusion using an autologous blood re-transfusion drain. One unit of blood costs approximately £120 the ABT drain less than half of this amount, there is a significant cost saving in using autologous blood re-transfusion drains. We conclude that using Autologous blood Re-transfusion drains is safe, cost effective and reduces the need for homologous blood transfusion. If drains are to be used then Re-transfusion drains should be used

Aims. Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre. Methods. A retrospective review was performed of all gram-negative spinal infections (n = 32; median age 71 years; interquartile range 60 to 78), excluding surgical site infections, at a single centre between 2015 to 2020 with two- to six-year follow-up. Information regarding organism identification, antibiotic regime, and treatment outcomes (including clinical, radiological, and biochemical) were collected from clinical notes. Results. All patients had comorbidities and/or non-spinal procedures within the previous year. Most infections affected lumbar segments (20/32), with Escherichia coli the commonest organism (17/32). Causative organisms were identified by blood culture (23/32), biopsy/aspiration (7/32), or intraoperative samples (2/32). There were 56 different antibiotic regimes, with oral (PO) ciprofloxacin being the most prevalent (13/56; 17.6%). Multilevel, contiguous infections were common (8/32; 25%), usually resulting in bone destruction and collapse. Epidural collections were seen in 13/32 (40.6%). In total, five patients required surgery, three for neurological deterioration. Overall, 24 patients improved or recovered with a mean halving of CRP at 8.5 days (SD 6). At the time of review (two to six years post-diagnosis), 16 patients (50%) were deceased. Conclusion. This is the largest published cohort of gram-negative spinal infections. In older patients with comorbidities and/or previous interventions in the last year, a high level of suspicion must be given to gram-negative infection with blood cultures and biopsy essential. Early organism identification permits targeted treatment and good initial clinical outcomes; however, mortality is 50% in this cohort at a mean of 4.2 years (2 to 6) after diagnosis. Cite this article: Bone Jt Open 2024;5(5):435–443

Introduction: There is increasing awareness and concern among the medical profession, general public and media about the various complications of homologous blood transfusion. Primary arthroplasty of either the hip or knee has an estimated total bleeding of 1.51 (Lotke et al 1991), commonly resulting in transfusion. In knee arthroplasty, performed with the use of a tourniquet, almost all the bleeding occurs postoperatively. Several studies have shown that salvage of blood after the operation and reinfusion can reduce the need for homologous transfusion (Majkowski RS et al, Newman JH et al). We studied prospectively 100 consecutive patients for knee replacement to compare post-operative transfusion requirements in blood salvage and reinfusion group and a no drain technique. Methods: After written consent 100 consecutive patients for knee replacement surgery were randomly allocated by computer generated numbers to either the no drain group (n=50) or the reinfusion group (n=50). The patients were anaesthetised as deemed appropriate by their anaesthetist. All the patients were operated on using a tourniquet. At the end of surgery the wound was closed with or without a deep drain. The drain was attached to the Constavac CBC II closed suction system. Preoperative haemoglobin and haematocrit values were recorded. Homologous blood was transfused to the patients as per the standard protocol depending on the haematocrit and or haemoglobin at 4 & 8 hours post-operatively, as well as days 1,2 & 3. In the reinfusion group blood collected in the reservoir was transferred to the blood bag and reinfused at 5 hours or 500 mls depending which was earlier. At 8 hours the reservoir blood was collected and reinfused, no more blood was reinfused as per the manufacturer recommendations. Cardiovascular stability was assessed by hourly blood pressure and heart rate during the first 24 hours and twice daily thereafter. Blood loss was assesses by measuring the drain loss, assessing the wound ooze serial haematocrits and total transfusion requirements. Results: 50 patients were completed in each group. The mean preoperative haemoglobin in the drain group was 12.8 g/dl and in the no drain group it was 12.9 g/dl. No difference in predisposing factors for bleeding was recorded in the two groups. The mean volume of blood collected in the drain group was 1008mls and the mean volume of autologous transfused was 864 mls. 14% of patients in both groups had no requirement for homologous blood. There was no significant difference in the homologous blood transfusion in the two groups over the study period (up to day 3 post op), the no drain group requiring and average of 2.1 units of packed cells the reinfusion group requiring an average of 1.8 units of packed cells in total. The homologous blood requirements in the drain group was significantly reduced on day 2 in comparison to the no drain group, but as noted there was no overall reduction in homologous requirements. Cardiovascularly 16% of patients with a drain had at least one episode of hypotension (Bp < 90 systolic) compared with 20% of patients in the no drain group. The group without a drain had a significant increase in wound ooze (70% compared with 44%). Conclusion: Post-operative blood salvaging and autologous transfusion following primary knee replacement under tourniquet in this study did not significantly reduce the patient’s requirement for homologous blood transfusion in the first 3 days post operatively. There was a significant increase in wound ooze in the no drain group but as shown this has not result in an increase in cardiovascular instability or an increase in transfusion requirements

Patients who are Jehovah's witnesses do not accept blood transfusions. Thus, total hip arthroplasty can be challenging in this group of patients due to the potential for blood loss. Multiple strategies have been developed in order to prevent blood loss. A 76-year-old female, Jehovah's witness medicated with a platelet antiaggregant, presented to the emergency department after a fall from standing height. Clinically, she had pain mobilizing the right lower limb and radiological examination revealed an acetabular fracture with femoral head protrusion and ipsilateral isquiopubic fracture. Skeletal traction was applied to the femur during three weeks and no weight bearing was maintained during the following weeks. Posteriorly, there was an evolution to hip osteoarthritis with necrosis of the femoral head. The patient was submitted to surgery six months after the initial trauma, for a total hip arthroplasty. The surgery was performed with hypotensive anaesthesia, careful surgical technique and meticulous haemostasis and there was no need for blood transfusion. Posteriorly, there was a positive clinical evolution with progressive improvement on function and deambulation. Total hip arthroplasty may be safely carried out with good clinical outcomes in Jehovah's witnesses, without the need for blood transfusion, if proper perioperative precautions are taken, as has already been shown in previous studies

Aims. Lumbar spinal stenosis (LSS) is a common skeletal system disease that has been partly attributed to genetic variation. However, the correlation between genetic variation and pathological changes in LSS is insufficient, and it is difficult to provide a reference for the early diagnosis and treatment of the disease. Methods. We conducted a transcriptome-wide association study (TWAS) of spinal canal stenosis by integrating genome-wide association study summary statistics (including 661 cases and 178,065 controls) derived from Biobank Japan, and pre-computed gene expression weights of skeletal muscle and whole blood implemented in FUSION software. To verify the TWAS results, the candidate genes were furthered compared with messenger RNA (mRNA) expression profiles of LSS to screen for common genes. Finally, Metascape software was used to perform enrichment analysis of the candidate genes and common genes. Results. TWAS identified 295 genes with permutation p-values < 0.05 for skeletal muscle and 79 genes associated for the whole blood, such as RCHY1 (PTWAS = 0.001). Those genes were enriched in 112 gene ontology (GO) terms and five Kyoto Encyclopedia of Genes and Genomes pathways, such as ‘chemical carcinogenesis - reactive oxygen species’ (LogP value = −2.139). Further comparing the TWAS significant genes with the differentially expressed genes identified by mRNA expression profiles of LSS found 18 overlapped genes, such as interleukin 15 receptor subunit alpha (IL15RA) (PTWAS = 0.040, PmRNA = 0.010). Moreover, 71 common GO terms were detected for the enrichment results of TWAS and mRNA expression profiles, such as negative regulation of cell differentiation (LogP value = −2.811). Conclusion. This study revealed the genetic mechanism behind the pathological changes in LSS, and may provide novel insights for the early diagnosis and intervention of LSS. Cite this article: Bone Joint Res 2023;12(6):387–396

Routine post-operative bloods following all elective arthroplasty may be unnecessary. This retrospective cohort study aims to define the proportion of post-operative tests altering clinical management. Clinical coding identified all elective hip or knee joint replacement under Hawkes Bay District Health Board contract between September 2019-December 2020 (N=373). Uni-compartmental and bilateral replacements, procedures performed for cancer, and those with insufficient data were excluded. Demographics, perioperative technique, and medical complication data was collected. Pre- and post-operative blood tests were assessed. Outcome measures included clinical intervention for abnormal post-operative sodium (Na), creatinine (Cr), haemoglobin (Hb), or potassium (K) levels. A cost-benefit analysis assessed unnecessary testing. 350 patients were Included. Median age was 71 (range 34-92), with 46.9% male. Only 26 abnormal post-operative results required intervention (7.1%). 11 interventions were for low Na, 4 for low K, and 4 for elevated Cr. Only 7 patients were transfused blood products. Older age (p=0.009) and higher ASA (p=0.02) were associated with intervention of any kind. Abnormal preoperative results significantly predicted intervention for Na (p<0.05) and Cr (p<0.05). All patients requiring treatment for K used diuretic medication. Preoperative Hb level was not associated with need for transfusion. Overall, there were 1027 unnecessary investigations resulting in $18,307 excess expenditure. Our study identified that the majority of elective arthroplasty patients do not require routine postoperative blood testing. We recommend investigations for patients with preoperative electrolyte abnormality, those taking diuretics, and patients with significant blood loss noted intra-operatively. In future, a larger, randomised controlled trial would be useful to confirm these factors

Purpose : The evaluation of the results of the comparison, between homologous blood transfusion and reinfusion of wound drainage blood, to patients with primary total knee replacement. Materials and methods: A study on 44 consequent patients,who underwent to primary total knee replacement. Study group comprised 29 patients, employing a post operative autologous collection system and the control group 15 patients, using a standard drainage system. The patiens of the control group transfused with homologous blood when it was needed. The amount of drainage blood autotransfused in the study group was 633,15cm3 per patient, approximately. The preoperative haematocrit of this group was 39,24% average. In the study group, 10/29 patients required two extra units of homologous blood per patient,where the preoperative haematocrit was 36,01% average. The control group, required 2,66 units of homologous blood per patient, wherees the preoperative haematocrit was 39,23% average. Results : The haematocrit in the 3rd post operative days, to the group of autotransfusion, was 32,70% average, while to the group of homologous blood transfusion was 31,91%. The temperature was approximately at the same levels to both groups of patients, post operatively, with a mean rate of 38,350C and it’s duration was two days post operatively, average. There were no complications to both groups after the operation. Conclusions: The system of reinfusion of unwashed shed whole blood is effective and safe as far as it concerns the decrease of the dangers from the homologous blood transfusion. Moreover, the cost is cheaper comparing to the homologous transfusion, whereas it is the solution of choice, to the people who refuse the blood transfusion, due to religion reasons

Aims: To derive a formula for blood loss estimation and also to assess if high body weight is protective against blood transfusion following elective arthroplasty? Methods: Retrospective study of patients undergoing elective primary hip arthroplasty. Weight of the patient, pre and postoperative haematological investigations and details of blood transfusion were collected. Results: Formula for blood loss estimation was derived, Blood loss= ( 70 x body weight in Kg) x (drop in haematocrit) (Pre-op haematocrit+ post-op haematocrit)Ö2. The mean blood loss in 86 patients was 1631ml. Mean blood lost/Kg body weight was 22.6ml. 36/86 patients had < 21ml/kg (42%) and 50/86 had > 21ml/kg blood loss (58%). 21 ml/kg represents 30% loss of blood volume. Patients losing > 21ml/kg blood had signiþcantly higher blood transfusion rates (Chi squared test; χ2(1)= 5.50, p=0.02). The amount of blood loss increases with weight of patients (p< 0.01). The rates of transfusion in patients with ≤ 72 kg weight (circulatory volume ~ 5 litre) was 51% (23/45), and in patients > 72 kg it was 36.5% (15/41). Rates of transfusion were related to pre-op Hb but were unaffected by gender, age, cemented/uncemented prosthesis, surgical approach, type of prosthesis, use of drains, grade of surgeon, type of anaesthetic. Conclusion: Calculated blood loss > 21ml/kg and patientñs low body weight are associated with increased risk of blood transfusion