Aims. Elevated blood cobalt levels secondary to metal-on-metal (MoM) hip arthroplasties are a suggested risk factor for developing cardiovascular complications including cardiomyopathy. Clinical studies assessing patients with MoM hips using left ventricular ejection fraction (LVEF) have found conflicting evidence of cobalt-induced cardiomyopathy. Global longitudinal strain (GLS) is an echocardiography measurement known to be more sensitive than LVEF when diagnosing early cardiomyopathies. The extent of cardiovascular injury, as measured by GLS, in patients with elevated blood cobalt levels has not previously been examined. Methods. A total of 16 patients with documented blood cobalt ion levels above 13 µg/l (13 ppb, 221 nmol/l) were identified from a regional arthroplasty database. They were matched with eight patients awaiting hip arthroplasty. All patients underwent echocardiography, including GLS, investigating potential signs of cardiomyopathy. Results. Patients with MoM hip arthroplasties had a mean blood cobalt level of 29 µg/l (495 nmol/l) compared to 0.01 µg/l (0.2 nmol/l) in the control group. GLS readings were available for seven of the MoM cohort, and were significantly lower when compared with controls (-15.5% vs -18% (MoM vs control); p = 0.025)). Pearson correlation demonstrated that GLS significantly correlated with blood cobalt level (r = 0.8521; p < 0.001). However, there were no differences or correlations for other echocardiography measurements, including LVEF (64.3% vs 63.7% (MoM vs control); p = 0.845). Conclusion. This study supports the hypothesis that patients with elevated blood cobalt levels above 13 µg/l in the presence of a MoM hip implant may have impaired cardiac function compared to a control group of patients awaiting hip arthroplasty. It is the first study to use the more sensitive parameter of GLS to assess for any cardiac contractile dysfunction in patients with a MoM hip implant and a normal LVEF. Larger studies should be performed to determine the potential of GLS as a predictor of cardiac complications in patients with MoM arthroplasties. Cite this article: Bone Joint J 2024;106-B(3 Supple A):51–58

Aims. Blood transfusion and postoperative anaemia are complications of total knee arthroplasty (TKA) that are associated with substantial healthcare costs, morbidity, and mortality. There are few data from large datasets on the risk factors for these complications. Methods. We retrospectively reviewed the records of TKA patients from a single tertiary care institution from February 2016 to December 2020. There were a total of 14,901 patients in this cohort with a mean age of 67.9 years (SD 9.2), and 5,575 patients (37.4%) were male. Outcomes included perioperative blood transfusion and postoperative anaemia, defined a priori as haemoglobin level < 10 g/dl measured on the first day postoperatively. In order to establish a preoperative haemoglobin cutoff, we investigated a preoperative haemoglobin level that would limit transfusion likelihood to ≤ 1% (13 g/dl) and postoperative anaemia likelihood to 4.1%. Risk factors were assessed through multivariable Poisson regression modelling with robust error variance. Results. In multivariable analyses, each gram of tranexamic acid reduced transfusion likelihood by 39% (adjusted risk ratio (ARR) 0.61 (95% confidence interval (CI) 0.47 to 0.78)). Risk factors associated with an increased risk of transfusion included operating time (ARR 2.07 (95% CI 1.54 to 2.77)) and drain use (ARR 1.73 (95% CI 1.34 to 2.24)). Conclusion. In this study, we found that increased tranexamic acid dosing, decreased operating time, and decreased drain use may reduce transfusions following TKA. We also established a single preoperative haemoglobin cutoff of 13 g/dl that could help minimize transfusions and reduce postoperative complete blood counts. Cite this article: Bone Joint J 2023;105-B(10):1086–1093

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

Aims. The aim of this study was to examine perioperative blood transfusion practice, and associations with clinical outcomes, in a national cohort of hip fracture patients. Methods. A retrospective cohort study was undertaken using linked data from the Scottish Hip Fracture Audit and the Scottish National Blood Transfusion Service between May 2016 and December 2020. All patients aged ≥ 50 years admitted to a Scottish hospital with a hip fracture were included. Assessment of the factors independently associated with red blood cell transfusion (RBCT) during admission was performed, alongside determination of the association between RBCT and hip fracture outcomes. Results. A total of 23,266 individual patient records from 18 hospitals were included. The overall rate of blood transfusion during admission was 28.7% (n = 6,685). There was inter-hospital variation in transfusion rate, ranging from 16.6% to 37.4%. Independent perioperative factors significantly associated with RBCT included older age (90 to 94 years, odds ratio (OR) 3.04 (95% confidence interval (CI) 2.28 to 4.04); p < 0.001), intramedullary fixation (OR 7.15 (95% CI 6.50 to 7.86); p < 0.001), and sliding hip screw constructs (OR 2.34 (95% CI 2.19 to 2.50); p < 0.001). Blood transfusion during admission was significantly associated with higher rates of 30-day mortality (OR 1.35 (95% CI 1.19 to 1.53); p < 0.001) and 60-day mortality (OR 1.54 (95% CI 1.43 to 1.67); p < 0.001), as well as delays to postoperative mobilization, higher likelihood of not returning to their home, and longer length of stay. Conclusion. Blood transfusion after hip fracture was common, although practice varied nationally. RBCT is associated with adverse outcomes, which is most likely a reflection of perioperative anaemia, rather than any causal effect. Use of RBCT does not appear to reverse this effect, highlighting the importance of perioperative blood loss reduction. Cite this article: Bone Joint J 2022;104-B(11):1266–1272

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

We have investigated the effect of using tranexamic acid (TXA) during peri-acetabular osteotomy (PAO) on peri-operative blood loss and blood transfusion requirements. In addition we analysed whether the use of TXA was associated with an increased risk of venous thromboembolism (VTE) following this procedure. A consecutive series of 96 PAOs, performed by a single surgeon, were reviewed. A total of 48 patients received TXA and 48 did not. The TXA group received a continuous infusion of TXA at a rate of 10 mg/kg/h. The primary outcome measure was the requirement for blood transfusion. Secondary outcomes included total blood loss, the decrease in the level of haemoglobin in the blood, the length of hospital stay, and the complications of this treatment. The mean rate of transfusion was significantly lower in the TXA group (62.5% vs 12.5%, p < 0.001). The mean blood loss was also significantly reduced in the TXA group (1.9 L (standard deviation (. sd. ) 0.9) vs 1.5 L (. sd. 0.7), p < 0.01). No post-operative episodes of VTE were identified in either group. . The use of TXA reduced the blood loss and the rate of transfusion after PAO significantly, without adverse effects such as an increased rate of VTE. Cite this article: Bone Joint J 2015;97-B:1604–7

Aims. The aim of this study was to perform a systematic review of the evidence for the use of intraoperative cell salvage in patients undergoing revision hip arthroplasty, and specifically to analyze the available data in order to quantify any associated reduction in the use of allogenic blood transfusion, and the volume which is used. Methods. An electronic search of MEDLINE (PubMed), Embase, Scopus, and the Cochrane Library was completed from the date of their inception to 24 February 2022, using a search strategy and protocol created in conjunction with the PRISMA statement. Inclusion criteria were patients aged > 18 years who underwent revision hip arthroplasty when cell salvage was used. Studies in which pre-donated red blood cells were used were excluded. A meta-analysis was also performed using a random effects model with significance set at p = 0.05. Results. Of the 283 studies which were identified, 11 were included in the systematic review, and nine in the meta-analysis. There was a significant difference (p < 0.001) in the proportion of patients requiring allogenic transfusion between groups, with an odds ratio of 0.331 (95% confidence interval (CI) 0.165 to 0.663) associated with the use of cell salvage. For a total of 561 patients undergoing revision hip arthroplasty who were treated with cell salvage, 247 (44.0%) required allogenic transfusion compared with 418 of 643 patients (65.0%) who were treated without cell salvage. For those treated with cell salvage, the mean volume of allogenic blood which was required was 1.95 units (390 ml) per patient (0.7 to 4.5 units), compared with 3.25 units (650 ml) per patient (1.2 to 7.0 units) in those treated without cell salvage. The mean difference of -1.91 units (95% CI -4.0 to 0.2) in the meta-analysis was also significant (p = 0.003). Conclusion. We found a a significant reduction in the need for allogenic blood transfusion when cell salvage was used in patients undergoing revision hip arthroplasty, supporting its routine use in these patients. Further research is required to determine whether this effect is associated with types of revision arthroplasty of differing complexity. Cite this article: Bone Joint J 2023;105-B(10):1038–1044

Aims. The pre-operative level of haemoglobin is the strongest predictor of the peri-operative requirement for blood transfusion after total knee arthroplasty (TKA). There are, however, no studies reporting a value that could be considered to be appropriate pre-operatively. . This study aimed to identify threshold pre-operative levels of haemoglobin that would predict the requirement for blood transfusion in patients who undergo TKA. . Patients and Methods. Analysis of receiver operator characteristic (ROC) curves of 2284 consecutive patients undergoing unilateral TKA was used to determine gender specific thresholds predicting peri-operative transfusion with the highest combined sensitivity and specificity (area under ROC curve 0.79 for males; 0.78 for females). Results. Threshold levels of 13.75 g/dl for males and 12.75 g/dl for females were identified. The rates of transfusion in males and females, respectively above these levels were 3.37% and 7.11%, while below these levels, they were 16.13% and 28.17%. Pre-operative anaemia increased the rate of transfusion by 6.38 times in males and 6.27 times in females. Blood transfusion was associated with an increased incidence of early post-operative confusion (odds ratio (OR) = 3.44), cardiac arrhythmia (OR = 5.90), urinary catheterisation (OR = 1.60), the incidence of deep infection (OR = 4.03) and mortality (OR = 2.35) one year post-operatively, and increased length of stay (eight days vs six days, p < 0.001). . Conclusion. Uncorrected low pre-operative levels of haemoglobin put patients at potentially modifiable risk and attempts should be made to correct this before TKA. Target thresholds for the levels of haemoglobin pre-operatively in males and females are proposed. Take home message: Low pre-operative haemoglobin levels put patients at unnecessary risk and should be corrected prior to surgery. Cite this article: Bone Joint J 2016;98-B:490–7

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

We undertook a prospective, randomised study in order to evaluate the efficacy of clamping the drains after intra-articular injection of saline with 1:500 000 adrenaline compared with post-operative blood salvage in reducing blood loss in 212 total knee arthroplasties. The mean post-operative drained blood volume after drain clamping was 352.1 ml compared to 662.3 ml after blood salvage (p < 0.0001). Allogenic blood transfusion was needed in one patient in the drain group and for three in the blood salvage group. Drain clamping with intra-articular injection of saline with adrenaline is more effective than post-operative autologous blood transfusion in reducing blood loss during total knee arthroplasty

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

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

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

Aims. The first aim of this study was to evaluate whether preoperative renal function is associated with postoperative changes in whole blood levels of metal ions in patients who have undergone a Birmingham Hip Resurfacing (BHR) arthroplasty with a metal-on-metal bearing. The second aim was to evaluate whether exposure to increased cobalt (Co) and chromium (Cr) levels for ten years adversely affected renal function. Methods. As part of a multicentre, prospective post-approval study, whole blood samples were sent to a single specialized laboratory to determine Co and Cr levels, and the estimated glomerular filtration rate (eGFR). The study included patients with 117 unrevised unilateral BHRs. There were 36 females (31%). The mean age of the patients at the time of surgery of 51.3 years (SD 6.5), and they all had preoperative one-, four-, five-, and ten-year laboratory data. The mean follow-up was 10.1 years (SD 0.2). Results. Median Co levels at one year postoperatively increased significantly compared with the preoperative values, by a factor of 9.7, from 0.13 to 1.26 ppb (p < 0.001), and the median Cr levels increased significantly by a factor of 2.5, from 0.60 to 1.50 ppb (p < 0.001). Lower preoperative eGFRs were associated with significantly larger increases in Co at one year compared with the preoperative levels (ρ = -0.26; p = 0.005), but there was no relationship between preoperative eGFRs and changes in Cr at one year (ρ = -0.13; p = 0.153). Metal levels remained relatively constant with the passage of time, with a median ten-year value of 1.12 ppb for Co and 1.29 ppb for Cr. There was no significant relationship between the Co and Cr levels at ten-year follow-up and the change in eGFR from the preoperative level to that at ten years (ρ = -0.02; p = 0.827 for Co; ρ = -0.008; p = 0.933 for Cr). Conclusion. Although patients with lower preoperative eGFRs tended to have larger increases in Co levels at one year, increased metal levels for patients who underwent unilateral BHR did not adversely affect renal function during the first ten postoperative years. Cite this article: Bone Joint J 2024;106-B(3 Supple A):44–50

Aims. To analyze the short-term outcome of two types of total wrist arthroplasty (TWA) in terms of wrist function, migration, and periprosthetic bone behaviour. Methods. A total of 40 patients suffering from non-rheumatoid wrist arthritis were enrolled in a randomized controlled trial comparing the ReMotion and Motec TWAs. Patient-rated and functional outcomes, radiological changes, blood metal ion levels, migration measured by model-based radiostereometric analysis (RSA), bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), complications, loosening, and revision rates at two years were compared. Results. Patient-Rated Wrist and Hand Evaluation (PRWHE) scores, abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) scores, and pain improved similarly and significantly in both groups. Wrist motion improved significantly in the Motec group only, and forearm rotation in the ReMotion group only. Cobalt (Co) and chromium (Cr) blood ion levels were significantly higher in the metal-on-metal (MoM) Motec group than in the metal-on-polyethylene (MoP) ReMotion group. Mean total translation was 0.65 mm (95% confidence interval (CI) 0.26 to 1.12) and 0.27 mm (95% CI 0.14 to 0.47) for the ReMotion carpal and radial components, and 0.32 mm (95% CI 0.22 to 0.45) and 0.26 mm (95% CI 0.20 to 0.34) for the Motec metacarpal and radial components, respectively. Apart from dorsal and volar tilts, which were significantly higher for the radial ReMotion than for the Motec component, no significant differences in absolute migration occurred. BMD around the radial components never returned to baseline. Almost one-third of patients required reoperation due to complications. Two ReMotion implants were revised to Motec TWAs due to carpal component loosening, and three Motec MoM articulations were revised to metal-on-polyether ether ketone due to painful synovitis. Conclusion. Both implants provided matched function and were stable at short-term follow-up, but with a high complication rate. This procedure should be restricted to specialist centres undertaking prospective analysis until its role is clarified. Cite this article: Bone Joint J 2022;104-B(10):1132–1141

Aims. Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remains a challenge. A novel surgical technique named ‘tibial cortex transverse transport’ (TTT) has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In the present study, we explored the potential biological mechanisms of TTT surgery using various techniques in a rat TTT animal model. Methods. A novel rat model of TTT was established with a designed external fixator, and effects on wound healing were investigated. Laser speckle perfusion imaging, vessel perfusion, histology, and immunohistochemistry were used to evaluate the wound healing processes. Results. Gross and histological examinations showed that TTT technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In the TTT group, haematoxylin and eosin (H&E) staining demonstrated a better epidermis and dermis recovery, while immunohistochemical staining showed that TTT technique promoted local collagen deposition. The TTT technique also benefited to angiogenesis and immunomodulation. In the TTT group, blood flow in the wound area was higher than that of other groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the TTT group with double immune-labelling of CD31 and α-Smooth Muscle Actin (α-SMA). The number of M2 macrophages at the wound site in the TTT group was also increased. Conclusion. The TTT technique accelerated wound healing through enhanced angiogenesis and immunomodulation. Cite this article: Bone Joint Res 2022;11(4):189–199

The April 2024 Hip & Pelvis Roundup. 360. looks at: Impaction bone grafting for femoral revision hip arthroplasty with the Exeter stem; Effect of preoperative corticosteroids on postoperative glucose control in total joint replacement; Tranexamic acid in patients with a history of venous thromboembolism; Bisphosphonate use may be associated with an increased risk of periprosthetic hip fracture; A balanced approach: exploring the impact of surgical techniques on hip arthroplasty outcomes; A leap forward in hip arthroplasty: dual-mobility bearings reduce groin pain; A new perspective on complications: the link between blood glucose and joint infection risks

Aims. Calprotectin (CLP) is produced in neutrophils and monocytes and released into body fluids as a result of inflammation or infection. The aim of this study was to evaluate the utility of blood and synovial CLP in the diagnosis of chronic periprosthetic joint infection (PJI). Methods. Blood and synovial fluid samples were collected prospectively from 195 patients undergoing primary or revision hip and knee arthroplasty. Patients were divided into five groups: 1) primary total hip and knee arthroplasty performed due to idiopathic osteoarthritis (OA; n = 60); 2) revision hip and knee arthroplasty performed due to aseptic failure of the implant (AR-TJR; n = 40); 3) patients with a confirmed diagnosis of chronic PJI awaiting surgery (n = 45); 4) patients who have finished the first stage of the PJI treatment with the use of cemented spacer and were qualified for replantation procedure (SR-TJR; n = 25), and 5) patients with rheumatoid arthritis undergoing primary total hip and knee arthroplasty (RA; n = 25). CLP concentrations were measured quantitatively in the blood and synovial fluid using an immunoturbidimetric assay. Additionally, blood and synovial CRP, blood interleukin-6 (IL-6), and ESR were measured, and a leucocyte esterase (LE) strip test was performed. Results. Patients with PJI had higher CLP concentrations than those undergoing aseptic revision in blood (median PJI 2.14 mg/l (interquartile range (IQR) 1.37 to 3.56) vs AR-TJR 0.66 mg/l (IQR 0.3 to 0.83); p < 0.001) and synovial fluid samples (median PJI 20.46 mg/l (IQR 14.3 to 22.36) vs AR-TJR 0.7 mg/l (IQR 0.41 to 0.95); p < 0.001). With a cut-off value of 1.0 mg/l, blood CLP showed a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 87.5%, 89.4%, and 92.1%, respectively. For synovial fluid with a cut-off value of 1.5 mg/l, these were 95.6%, 95%, 95.5%, and 95%, respectively. Conclusion. This small study suggests that synovial and blood CLP are useful markers in chronic PJI diagnosis with similar or higher sensitivity and specificity than routinely used markers such as CRP, ESR, IL-6, and LE. CLP was not useful to differentiate patients with PJI from those with rheumatoid arthritis. Cite this article: Bone Joint J 2021;103-B(1):46–55

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. Methods. We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma. Results. Of the 14,584 included patients, the most commonly performed surgeries were knee arthroplasty (24.8%), hip arthroplasty (24.6%), and hip fracture surgery (17.4%). A total of 10.3% of patients received RBC transfusion; the proportion of patients receiving RBC transfusions varied widely based on the surgical subgroup (0.0% to 33.1%). Primary knee arthroplasty and hip arthroplasty, the two most common surgeries, were associated with in-hospital transfusion frequencies of 2.8% and 4.5%, respectively. RBC transfusion occurred in 25.0% of hip fracture surgeries, accounting for the greatest total number of RBC units transfused in our cohort (38.0% of all transfused RBC units). Platelet and plasma transfusions were uncommon. Conclusion. Orthopaedic surgeries were associated with variable rates of transfusion. The rate of RBC transfusion is highly dependent on the surgery type. Identifying surgeries with the highest transfusion rates, and further evaluation of factors that contribute to transfusion in identified at-risk populations, can serve to inform perioperative planning and blood bank requirements, and facilitate pre-emptive transfusion mitigation strategies. Cite this article: Bone Jt Open 2021;2(10):850–857

We investigated the effect of a fibrinolytic inhibitor, tranexamic acid, on blood loss and blood transfusion in knee arthroplasty by a randomised, double-blind study of 86 patients. A dose of 10 mg/kg body-weight of either tranexamic acid or placebo was given intravenously shortly before the release of the tourniquet, and repeated three hours later. The mean total blood loss was 730 ± 280 ml in the tranexamic acid group as against 1410 ± 480 ml in the placebo group (p < 0.001). Both the number of patients receiving blood transfusion and the number of blood units transfused were reduced to one-third in the treated group, and mean postoperative Hb concentrations were significantly higher after prophylaxis. The number of thromboembolic complications was the same in both groups. Tranexamic acid should be given prophylactically in order to be effective

Aims. The benefit of MRI in the preoperative assessment of scaphoid proximal fragment vascularity remains controversial. The purpose of this study is to compare preoperative MRI findings to intraoperative bleeding of the proximal scaphoid. Methods. A retrospective review of 102 patients who underwent surgery for scaphoid nonunion between January 2000 and December 2020 at a single institution were identified. Inclusion criteria were: isolated scaphoid nonunion; preoperative MRI assessing the proximal fragment vascularity; and operative details of the vascularity of the proximal fragment with the tourniquet deflated. MRI results and intraoperative findings were dichotomized as either ‘yes’ or ‘no’ for the presence of vascularity. A four-fold contingency table was used to analyze the utility of preoperative MRI with 95% confidence intervals. Relative risk was calculated for subgroups to analyze the association between variables and MRI accuracy. Results. Preoperative MRI identified 55 proximal scaphoid fragments with ischaemia and 47 with vascularized proximal fragments. After the proximal fragment was prepared, the tourniquet was deflated and assessed for bleeding; 63 proximal fragments had no bleeding and 39 demonstrated bleeding. MRI was not reliable or accurate in the assessment of proximal fragment vascularity when compared with intraoperative assessment of bleeding. No patient or MRI factors were identified to have a statistical impact on MRI accuracy. Conclusion. Current preoperative MRI protocols and diagnostic criteria do not provide a high degree of correlation with observed intraoperative assessment of proximal fragment bleeding. While preoperative MRI may assist in surgical planning, intraoperative assessment remains the best means for assessing proximal fragment vascularity in scaphoid nonunion. Future efforts should focus on the development of objective measures of osseous blood flow that may be performed intraoperatively. Cite this article: Bone Joint J 2023;105-B(6):657–662

Aims. Tranexamic acid (TXA) has been shown to reduce blood loss and transfusion requirements in patients undergoing orthopaedic surgery. There remains a lack of prospective evidence for the use of TXA in patients undergoing periacetabular osteotomy (PAO). The purpose of this study was to determine if intravenous (IV) TXA is effective in reducing calculated blood loss and transfusions after PAO. Methods. This was a single-centre prospective double-blind placebo-controlled randomized trial of 81 patients aged 12 to 45 years undergoing elective PAO by a single surgeon. The intervention group (n = 40) received two doses of IV TXA of a maximum 1 g in each dose; the control group (n = 41) received two doses of 50 ml 0.9% saline IV. The primary outcome was perioperative calculated blood loss. Secondary outcomes included allogenic transfusions and six-week postoperative complications. Results. There were no differences in demographics or intraoperative variables between study groups. The TXA group demonstrated lower mean calculated blood loss (1,265 ml, (SD 321) vs 1,515 ml, (SD 394); p = 0.002) and lower frequency of allogenic transfusion (10%/n = 4 vs 37%/n = 15; p = 0.008). Regression analyses associated TXA use with significant reductions in calculated blood loss (p < 0.001) and transfusion (p = 0.007) after adjusting for age, sex, body mass index, preoperative haemoglobin, cell-saver volume, intraoperative mean arterial blood pressure, and operating time. No patients suffered venous thromboembolic complications. Conclusion. In this trial, IV TXA decreased postoperative calculated blood loss by 293 ml and reduced the frequency of allogenic transfusions by 73% (37% vs 10%) following PAO. TXA may be safe and effective for reducing blood loss in patients undergoing PAO. Cite this article: Bone Joint J 2020;102-B(9):1151–1157

Aims. Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients. Methods. This was a prospective pilot study, including 24 patients divided into three groups, with eight patients each undergoing revision of their hip arthroplasty due to aseptic reasons, and low- and high-grade PJI, respectively. The number of intraoperative samples and the incidence of positive cultures were recorded for each patient. Additionally, venous blood samples and periarticular tissue samples were collected from each patient to determine miRNA expressions between the groups. MiRNA screening was performed by small RNA-sequencing using the miRNA next generation sequencing (NGS) discovery (miND) pipeline. Results. Overall, several miRNAs in plasma and tissue were identified to be progressively deregulated according to ongoing PJI. When comparing the plasma samples, patients with a high-grade infection showed significantly higher expression levels for hsa-miR-21-3p, hsa-miR-1290, and hsa-miR-4488, and lower expression levels for hsa-miR-130a-3p and hsa-miR-451a compared to the aseptic group. Furthermore, the high-grade group showed a significantly higher regulated expression level of hsa-miR-1260a and lower expression levels for hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-148b-5p, hsa-miR-301a-3p, hsa-miR-451a, and hsa-miR-454-3p compared to the low-grade group. No significant differences were found between the low-grade and aseptic groups. When comparing the tissue samples, the high-grade group showed significantly higher expression levels for 23 different miRNAs and lower expression levels for hsa-miR-2110 and hsa-miR-3200-3p compared to the aseptic group. No significant differences were found in miRNA expression between the high- and low-grade groups, as well as between the low-grade and aseptic groups. Conclusion. With this prospective pilot study, we were able to identify a circulating miRNA signature correlating with high-grade PJI compared to aseptic patients undergoing hip arthroplasty revision. Our data contribute to establishing miRNA signatures as potential novel diagnostic and prognostic biomarkers for PJI. Cite this article: Bone Jt Open 2024;5(6):479–488

Aims. The purpose of this study was to examine the efficacy and safety of carbazochrome sodium sulfonate (CSS) combined with tranexamic acid (TXA) on blood loss and inflammatory responses after primary total hip arthroplasty (THA), and to investigate the influence of different administration methods of CSS on perioperative blood loss during THA. Methods. This study is a randomized controlled trial involving 200 patients undergoing primary unilateral THA. A total of 200 patients treated with intravenous TXA were randomly assigned to group A (combined intravenous and topical CSS), group B (topical CSS), group C (intravenous CSS), or group D (placebo). Results. Mean total blood loss (TBL) in groups A (605.0 ml (SD 235.9)), B (790.9 ml (SD 280.7)), and C (844.8 ml (SD 248.1)) were lower than in group D (1,064.9 ml (SD 318.3), p < 0.001). We also found that compared with group D, biomarker level of inflammation, transfusion rate, pain score, and hip range of motion at discharge in groups A, B, and C were significantly improved. There were no differences among the four groups in terms of intraoperative blood loss (IBL), intramuscular venous thrombosis (IMVT), and length of hospital stay (LOS). Conclusion. The combined application of CSS and TXA is more effective than TXA alone in reducing perioperative blood loss and transfusion rates, inflammatory response, and postoperative hip pain, results in better early hip flexion following THA, and did not increase the associated venous thromboembolism (VTE) events. Intravenous combined with topical injection of CSS was superior to intravenous or topical injection of CSS alone in reducing perioperative blood loss. Cite this article: Bone Joint Res 2021;10(6):354–362

Aims. The modified Glasgow Prognostic Score (mGPS) uses preoperative CRP and albumin to calculate a score from 0 to 2 (2 being associated with poor outcomes). mGPS is validated in multiple carcinomas. To date, its use in soft-tissue sarcoma (STS) is limited, with only small cohorts reporting that increased mGPS scores correlates with decreased survival in STS patients. Methods. This retrospective multicentre cohort study identified 493 STS patients using clinical databases from six collaborating hospitals in three countries. Centres performed a retrospective data collection for patient demographics, preoperative blood results (CRP and albumin levels and neutrophil, leucocyte, and platelets counts), and oncological outcomes (disease-free survival, local, or metastatic recurrence) with a minimum of two years' follow-up. Results. We found that increased mGPS, tumour size, grade, neutrophil/lymphocyte ratio, and disease recurrence were associated with reduced survival. Importantly, mGPS was the best at stratifying prognosis and could be used in conjunction with tumour grade to sub-stratify patient survival. Conclusion. This study demonstrated that prognosis of localized STS strongly correlates with mGPS, as an increasing score is associated with a poorer outcome. We note that 203 patients (41%) with an STS have evidence of systemic inflammation. We recommend the mGPS and other biochemical blood indicators be introduced into the routine diagnostic assessment in STS patients to stratify patient prognosis. Its use will support clinical decision-making, especially when morbid treatment options such as amputation are being considered. Cite this article: Bone Joint J 2022;104-B(1):168–176

Aims. Given the possible radiation damage and inaccuracy of radiological investigations, particularly in children, ultrasound and superb microvascular imaging (SMI) may offer alternative methods of evaluating new bone formation when limb lengthening is undertaken in paediatric patients. The aim of this study was to assess the use of ultrasound combined with SMI in monitoring new bone formation during limb lengthening in children. Methods. In this retrospective cohort study, ultrasound and radiograph examinations were performed every two weeks in 30 paediatric patients undergoing limb lengthening. Ultrasound was used to monitor new bone formation. The number of vertical vessels and the blood flow resistance index were compared with those from plain radiographs. Results. We categorized the new bone formation into three stages: stage I (early lengthening), in which there was no obvious callus formation on radiographs and ultrasound; stage II (lengthening), in which radiographs showed low-density callus formation with uneven distribution and three sub-stages could be identified on ultrasound: in Ia punctate callus was visible; in IIb there was linear callus formation which was not yet connected and in IIc there was continuous linear callus. In stage III (healing), the bone ends had united, the periosteum was intact, and the callus had disappeared, as confirmed on radiographs, indicating healed bone. A progressive increase in the number of vertical vessels was noted in the early stages, peaking during stages IIb and IIc, followed by a gradual decline (p < 0.001). Delayed healing involved patients with a prolonged stage IIa or those who regressed to stage IIa from stages IIb or IIc during lengthening. Conclusion. We found that the formation of new bone in paediatric patients undergoing limb lengthening could be reliably evaluated using ultrasound when combined with the radiological findings. This combination enabled an improved assessment of the prognosis, and adjustments to the lengthening protocol. While SMI offered additional insights into angiogenesis within the new bone, its role primarily contributed to the understanding of the microvascular environment rather than directly informing adjustments of treatment. Cite this article: Bone Joint J 2024;106-B(7):751–758

Aims. To investigate the correlations among cytokines and regulatory T cells (T-regs) in ankylosing spondylitis (AS) patients, and their changes after anti-tumour necrosis factor-α (TNF-α) treatment. Methods. We included 72 AS patients with detailed medical records, disease activity score (Bath Ankylosing Spondylitis Disease Activity Index), functional index (Bath Ankylosing Spondylitis Functional Index), and laboratory data (interleukin (IL)-2, IL-4, IL-10, TNF-α, interferon (IFN)-γ, transforming growth factor (TGF)-β, ESR, and CRP). Their peripheral blood mononuclear cells (PBMCs) were marked with anti-CD4, anti-CD25, and anti-FoxP3 antibodies, and triple positive T cells were gated by flow cytometry as T-regs. Their correlations were calculated and the changes after anti-TNF-α therapy were compared. Results. The frequency of T-regs in PBMCs was positively correlated to ESR and CRP in AS (r = 0.35 and 0.43; p = 0.032 and 0.027, respectively), and there was also a significant correlation between serum level of TNF-α and CRP (p = 0.041). The frequency of T-regs in PBMCs positively correlated to serum levels of TNF-α, IL-10, and TGF-β, while IL-2, IL-4, and IFN-γ showed opposite results. After anti-TNF-α treatment, there were significantly lower serum levels of TNF-α, IL-10, TGF-β, and frequency of T-regs in PBMCs among these AS patients (p = 0.026, 0.032, 0.029, and 0.037, respectively). Conclusion. In AS patients, proinflammatory cytokine may give positive feedback to induce more T-reg production and anti-inflammatory cytokine secretion to suppress this inflammatory status, and they can be reversed by anti-TNF-α therapy. However, the detailed interactions among T-regs and complex cytokine networks in autoinflammatory diseases still need more studies and further functional assay. Cite this article: Bone Joint Res 2023;12(2):133–137

Aims. Degenerative cervical spondylosis (DCS) is a common musculoskeletal disease that encompasses a wide range of progressive degenerative changes and affects all components of the cervical spine. DCS imposes very large social and economic burdens. However, its genetic basis remains elusive. Methods. Predicted whole-blood and skeletal muscle gene expression and genome-wide association study (GWAS) data from a DCS database were integrated, and functional summary-based imputation (FUSION) software was used on the integrated data. A transcriptome-wide association study (TWAS) was conducted using FUSION software to assess the association between predicted gene expression and DCS risk. The TWAS-identified genes were verified via comparison with differentially expressed genes (DEGs) in DCS RNA expression profiles in the Gene Expression Omnibus (GEO) (Accession Number: GSE153761). The Functional Mapping and Annotation (FUMA) tool for genome-wide association studies and Meta tools were used for gene functional enrichment and annotation analysis. Results. The TWAS detected 420 DCS genes with p < 0.05 in skeletal muscle, such as ribosomal protein S15A (RPS15A) (PTWAS = 0.001), and 110 genes in whole blood, such as selectin L (SELL) (PTWAS = 0.001). Comparison with the DCS RNA expression profile identified 12 common genes, including Apelin Receptor (APLNR) (PTWAS = 0.001, PDEG = 0.025). In total, 148 DCS-enriched Gene Ontology (GO) terms were identified, such as mast cell degranulation (GO:0043303); 15 DCS-enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified, such as the sphingolipid signalling pathway (ko04071). Nine terms, such as degradation of the extracellular matrix (R-HSA-1474228), were common to the TWAS enrichment results and the RNA expression profile. Conclusion. Our results identify putative susceptibility genes; these findings provide new ideas for exploration of the genetic mechanism of DCS development and new targets for preclinical intervention and clinical treatment. Cite this article: Bone Joint Res 2023;12(1):80–90

Aims. Orthopaedic surgery uses many varied instruments with high-speed, high-impact, thermal energy and sometimes heavy instruments, all of which potentially result in aerosolization of contaminated blood, tissue, and bone, raising concerns for clinicians’ health. This study quantifies the aerosol exposure by measuring the number and size distribution of the particles reaching the lead surgeon during key orthopaedic operations. Methods. The aerosol yield from 17 orthopaedic open surgeries (on the knee, hip, and shoulder) was recorded at the position of the lead surgeon using an Aerodynamic Particle Sizer (APS; 0.5 to 20 μm diameter particles) sampling at 1 s time resolution. Through timestamping, detected aerosol was attributed to specific procedures. Results. Diathermy (electrocautery) and oscillating bone saw use had a high aerosol yield (> 100 particles detected per s) consistent with high exposure to aerosol in the respirable range (< 5 µm) for the lead surgeon. Pulsed lavage, reaming, osteotome use, and jig application/removal were medium aerosol yield (10 to 100 particles s. -1. ). However, pulsed lavage aerosol was largely attributed to the saline jet, osteotome use was always brief, and jig application/removal had a large variability in the associated aerosol yield. Suctioning (with/without saline irrigation) had a low aerosol yield (< 10 particles s. -1. ). Most surprisingly, other high-speed procedures, such as drilling and screwing, had low aerosol yields. Conclusion. This work suggests that additional precautions should be recommended for diathermy and bone sawing, such as enhanced personal protective equipment or the use of suction devices to reduce exposure. Cite this article: Bone Joint Res 2023;12(10):636–643

Aims. Knee osteoarthritis (OA) is characterized by a chronic inflammatory process involving multiple cytokine pathways, leading to articular cartilage degeneration. Intra-articular therapies using pharmaceutical or autologous anti-inflammatory factors offer potential non-surgical treatment options. Autologous protein solution (APS) is one such product that uses the patient’s blood to produce a concentrate of cells and anti-inflammatory cytokines. This study evaluated the effect of a specific APS intra-articular injection (nSTRIDE) on patient-reported outcome measures compared to saline in moderate knee OA. Methods. A parallel, double-blinded, placebo-controlled randomized controlled trial was conducted, where patients with unilateral moderate knee OA (Kellgren-Lawrence grade 2 or 3) received either nSTRIDE or saline (placebo) injection to their symptomatic knee. The primary outcome was the difference in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score at 12 months post-intervention. Secondary outcomes included WOMAC component scores, Knee injury and Osteoarthritis Outcome Score (KOOS), and visual analogue scale (VAS) scores at all follow-up timepoints (three, six, and 12 months). Results. A total of 40 patients were analyzed (21 nSTRIDE; 19 saline) in the study. No significant difference was found between nSTRIDE and saline groups for WOMAC total score at 12 months (mean difference -10.4 (95% CI -24.4 to 3.6; p = 0.141). There were no significant differences in WOMAC or KOOS scores across all timepoints. VAS scores favoured the saline group for both rest and worst pain scales at 12 months post-injection (mean difference (worst) 12 months 21.5 (95% CI 6.2 to 36.8; p = 0.008); mean difference (rest) 12 months 17.8 (95% CI 2.2 to 33.4; p = 0.026)). There were no adverse events recorded in either study group. Conclusion. Our study demonstrates no significant differences between nSTRIDE and saline groups in KOOS and WOMAC scores over time. Notably, APS injection resulted in significantly worse pain symptoms at 12 months compared to saline injection. Cite this article: Bone Joint J 2024;106-B(9):907–915

Aims. In metal-on-polyethylene (MoP) total hip arthroplasty (THA), large metal femoral heads have been used to increase stability and reduce the risk of dislocation. The increased size of the femoral head can, however, lead to increased taper corrosion, with the release of metal ions and adverse reactions. The aim of this study was to investigate the relationship between the size of the femoral head and the levels of metal ions in the blood in these patients. Methods. A total of 96 patients were enrolled at two centres and randomized to undergo MoP THA using either a 32 mm metal head or a femoral head of between 36 mm and 44 mm in size, being the largest possible to fit the thinnest available polyethylene insert. The levels of metal ions and patient-reported outcome measures (Oxford Hip Score, University of California, Los Angeles Activity Scale) were recorded at two and five years postoperatively. Results. At five years, the median levels of chromium, cobalt, and titanium were 0.5 μg/l (interquartile range (IQR) 0.50 to 0.62), 0.24 μg/l (IQR 0.18 to 0.30), and 1.16 μg/l (IQR 1.0 to 1.68) for the 32 mm group, and 0.5 μg/l (IQR 0.5 to 0.54), 0.23 μg/l (IQR 0.17 to 0.39), and 1.30 μg/l (IQR 1 to 2.05) for the 36 mm to 44 mm group, with no significant difference between the groups (p = 0.825, p = 1.000, p = 0.558). There were increased levels of metal ions at two years postoperatively in seven patients in the 32 mm group, compared with four in the 36 mm to 44 mm group, and at five years postoperatively in six patients in the 32 mm group, compared with seven in the 36 mm to 44 mm group. There was no significant difference in either the OHS (p = 0.665) or UCLA (p = 0.831) scores between patients with or without an increased level of metal ions. Conclusion. In patients who underwent MoP THA, we found no differences in the levels of metal ions five years postoperatively between those with a femoral head of 32 mm and those with a femoral head of between 36 mm and 44 mm, and no corrosion-related revisions. As taper corrosion can start after five years, there remains a need for longer-term studies investigating the relationship between the size of the femoral head size and corrosion in patients undergoing MoP THA. Cite this article: Bone Joint J 2024;106-B(3 Supple A):31–37

Aims. Metal-on-metal hip resurfacing (MoM-HR) has seen decreased usage due to safety and longevity concerns. Joint registries have highlighted the risks in females, smaller hips, and hip dysplasia. This study aimed to identify if reported risk factors are linked to revision in a long-term follow-up of MoM-HR performed by a non-designer surgeon. Methods. A retrospective review of consecutive MoM hip arthroplasties (MoM-HRAs) using Birmingham Hip Resurfacing was conducted. Data on procedure side, indication, implant sizes and orientation, highest blood cobalt and chromium ion concentrations, and all-cause revision were collected from local and UK National Joint Registry records. Results. A total of 243 hips (205 patients (163 male, 80 female; mean age at surgery 55.3 years (range 25.7 to 75.3)) with MoM-HRA performed between April 2003 and October 2020 were included. Mean follow-up was 11.2 years (range 0.3 to 17.8). Osteoarthritis was the most common indication (93.8%), and 13 hips (5.3%; 7M:6F) showed dysplasia (lateral centre-edge angle < 25°). Acetabular cups were implanted at a median of 45.4° abduction (interquartile range 41.9° - 48.3°) and stems neutral or valgus to the native neck-shaft angle. In all, 11 hips (4.5%; one male, ten females) in ten patients underwent revision surgery at a mean of 7.4 years (range 2.8 to 14.2), giving a cumulative survival rate of 94.8% (95% confidence interval (CI) 91.6% to 98.0%) at ten years, and 93.4% (95% CI 89.3% to 97.6%) at 17 years. For aseptic revision, male survivorship was 100% at 17 years, and 89.6% (95% CI 83.1% to 96.7%) at ten and 17 years for females. Increased metal ion levels were implicated in 50% of female revisions, with the remaining being revised for unexplained pain or avascular necrosis. Conclusion. The Birmingham MoM-HR showed 100% survivorship in males, exceeding the National Institute for Health and Care Excellence ‘5% at ten years’ threshold. Female sex and small component sizes are independent risk factors. Dysplasia alone is not a contraindication to resurfacing. Cite this article: Bone Jt Open 2023;4(11):853–858

Aims. The aim of this study was to examine whether tourniquet use can improve perioperative blood loss, early function recovery, and pain after primary total knee arthroplasty (TKA) in the setting of multiple-dose intravenous tranexamic acid. Methods. This was a prospective, randomized clinical trial including 180 patients undergoing TKA with multiple doses of intravenous tranexamic acid. One group was treated with a tourniquet during the entire procedure, the second group received a tourniquet during cementing, and the third group did not receive a tourniquet. All patients received the same protocol of intravenous tranexamic acid (20 mg/kg) before skin incision, and three and six hours later (10 mg/kg). The primary outcome measure was perioperative blood loss. Secondary outcome measures were creatine kinase (CK), CRP, interleukin-6 (IL-6), visual analogue scale (VAS) pain score, limb swelling ratio, quadriceps strength, straight leg raising, range of motion (ROM), American Knee Society Score (KSS), and adverse events. Results. The mean total blood loss was lowest in the no-tourniquet group at 867.32 ml (SD 201.11), increased in the limited-tourniquet group at 1024.35 ml (SD 176.35), and was highest in the tourniquet group at 1,213.00 ml (SD 211.48). The hidden blood loss was lowest in the no-tourniquet group (both p < 0.001). There was less mean intraoperative blood loss in the tourniquet group (77.48 ml (SD 24.82)) than in the limited-tourniquet group (137.04 ml (SD 26.96)) and the no-tourniquet group (212.99 ml (SD 56.35); both p < 0.001). Patients in the tourniquet group showed significantly higher levels of muscle damage and inflammation biomarkers such as CK, CRP, and IL-6 than the other two groups (p < 0.05). Outcomes for VAS pain scores, limb swelling ratio, quadriceps strength, straight leg raising, ROM, and KSS were significantly better in the no-tourniquet group at three weeks postoperatively (p < 0.05), but there were no significant differences at three months. No significant differences were observed among the three groups with respect to transfusion rate, thrombotic events, or the length of hospital stay. Conclusion. Patients who underwent TKA with multiple doses of intravenous tranexamic acid but without a tourniquet presented lower total blood loss and hidden blood loss, and they showed less postoperative inflammation reaction, less muscle damage, lower VAS pain score, and better early knee function. Our results argue for not using a tourniquet during TKA. Cite this article: Bone Joint Res 2020;9(6):322–332

Aims. Intra-articular administration of antibiotics during primary total knee arthroplasty (TKA) may represent a safe, cost-effective strategy to reduce the risk of acute periprosthetic joint infection (PJI). Vancomycin with an aminoglycoside provides antimicrobial cover for most organisms isolated from acute PJI after TKA. However, the intra-articular doses required to achieve sustained therapeutic intra-articular levels while remaining below toxic serum levels is unknown. The purpose of this study is to determine the intra-articular and serum levels of vancomycin and tobramycin over the first 24 hours postoperatively after intra-articular administration in primary cementless TKA. Methods. A prospective cohort study was performed. Patients were excluded if they had poor renal function, known allergic reaction to vancomycin or tobramycin, received intravenous vancomycin, or were scheduled for same-day discharge. All patients received 600 mg tobramycin and 1 g of vancomycin powder suspended in 25 cc of normal saline and injected into the joint after closure of the arthrotomy. Serum from peripheral venous blood and drain fluid samples were collected at one, four, and 24 hours postoperatively. All concentrations are reported in µg per ml. Results. A total of 22 patients were included in final analysis. At one, four, and 24 hours postoperatively, mean (95% confidence interval (CI)) serum concentrations were 2.4 (0.7 to 4.1), 5.0 (3.1 to 6.9), and 4.8 (2.8 to 6.9) for vancomycin and 4.9 (3.4 to 6.3), 7.0 (5.8 to 8.2), and 1.3 (0.8 to 1.8) for tobramycin; intra-articular concentrations were 1,900.6 (1,492.5 to 2,308.8), 717.9 (485.5 to 950.3), and 162.2 (20.5 to 304.0) for vancomycin and 2,105.3 (1,389.9 to 2,820.6), 403.2 (266.6 to 539.7), and 98.8 (0 to 206.5) for tobramycin. Conclusion. Intra-articular administration of 1 g of vancomycin and 600 mg of tobramycin as a solution after closure of the arthrotomy in primary cementless TKA achieves therapeutic intra-articular concentrations over the first 24 hours postoperatively and does not reach sustained toxic levels in peripheral blood. Cite this article: Bone Joint J 2021;103-B(11):1702–1708

Aims. For cementless implants, stability is initially attained by an interference fit into the bone and osteo-integration may be encouraged by coating the implant with bioactive substances. Blood based autologous glue provides an easy, cost-effective way of obtaining high concentrations of growth factors for tissue healing and regeneration with the intention of spraying it onto the implant surface during surgery. The aim of this study was to incorporate nucleated cells from autologous bone marrow (BM) aspirate into gels made from the patient’s own blood, and to investigate the effects of incorporating three different concentrations of platelet rich plasma (PRP) on the proliferation and viability of the cells in the gel. Methods. The autologous blood glue (ABG) that constituted 1.25, 2.5, and 5 times concentration PRP were made with and without equal volumes of BM nucleated cells. Proliferation, morphology, and viability of the cells in the glue was measured at days 7 and 14 and compared to cells seeded in fibrin glue. Results. Overall, 2.5 times concentration of PRP in ABG was capable of supporting the maximum growth of cells isolated from the BM aspirate and maintain their characteristics. Irrespective of PRP concentration, cells in ABG had statistically significantly higher viability compared to cells in fibrin glue. Conclusion. In vitro this novel autologous gel is more capable of supporting the growth of cells in its structure for up to 14 days, compared to commercially available fibrin-based sealants, and this difference was statistically significant. Cite this article: Bone Joint Res 2020;9(7):402–411

Aims. The aim of this study was to explore the genetic correlation and causal relationship between blood plasma proteins and rheumatoid arthritis (RA). Methods. Based on the genome-wide association studies (GWAS) summary statistics of RA from European descent and the GWAS summary datasets of 3,622 plasma proteins, we explored the relationship between RA and plasma proteins from three aspects. First, linkage disequilibrium score regression (LD score regression) was applied to detect the genetic correlation between RA and plasma proteins. Mendelian randomization (MR) analysis was then used to evaluate the causal association between RA and plasma proteins. Finally, GEO2R was used to screen the differentially expressed genes (DEGs) between patients with RA and healthy controls. Results. We found that seven kinds of plasma proteins had genetic correlations with RA, such as Soluble Receptor for Advanced Glycation End Products (sRAGE) (correlation coefficient = 0.2582, p = 0.049), vesicle transport protein USE1 (correlation coefficient = 0.1337, p = 0.018), and spermatogenesis-associated protein 20 (correlation coefficient = 0.3706, p = 0.018). There was a significant causal relationship between sRAGE and RA. By comparing the genes encoding seven plasma proteins, we found that only USE1 was a DEG associated with RA. Conclusion. Our study identified a set of candidate plasma proteins that showed signals correlated with RA. Since the results of this study need further experimental verification, they should be interpreted with caution. However, we hope that this paper will provide new insights for the discovery of pathogenic genes and RA pathogenesis in the future. Cite this article: Bone Joint Res 2022;11(2):134–142

Aims. In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss. Methods. TRAC-24 was a prospective, phase IV, single-centre, open label, parallel group, randomized controlled trial on patients undergoing TKA, including those labelled as high-risk. The primary outcome was indirect calculated blood loss (IBL) at 48 hours. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional 24-hour postoperative oral regime of four 1 g doses, while Group 2 only received the intraoperative dose and Group 3 did not receive any TXA. Results. Between July 2016 and July 2018, 552 patients were randomized to either Group 1 (n = 241), Group 2 (n = 243), or Group 3 (n = 68), and 551 were included in the final analysis. The blood loss did differ significantly between the two intervention groups (733.5 ml (SD 384.0) for Group 1 and 859.2 ml (SD 363.6 ml) for Group 2; mean difference -125.8 ml (95% confidence interval -194.0 to -57.5; p < 0.001). No differences in mortality or thromboembolic events were observed in any group. Conclusion. These data support the hypothesis that in TKA, a TXA regime consisting of IV 1 g perioperatively and four oral 1 g doses over 24 hours postoperatively significantly reduces blood loss beyond that achieved with a single IV 1 g perioperative dose alone. TXA appears safe in patients with history of thromboembolic, cardiovascular, and cerebrovascular disease. Cite this article: Bone Joint J 2021;103-B(10):1595–1603

Aims. Fungal and mycobacterial periprosthetic joint infections (PJI) are rare events. Clinicians are wary of missing these diagnoses, often leading to the routine ordering of fungal and mycobacterial cultures on periprosthetic specimens. Our goal was to examine the utility of these cultures and explore a modern bacterial culture technique using bacterial blood culture bottles (BCBs) as an alternative. Methods. We performed a retrospective review of patients diagnosed with hip or knee PJI between 1 January 2010 and 31 December 2019, at the Mayo Clinic in Rochester, Minnesota, USA. We included patients aged 18 years or older who had fungal, mycobacterial, or both cultures performed together with bacterial cultures. Cases with positive fungal or mycobacterial cultures were reviewed using the electronic medical record to classify the microbiological findings as representing true infection or not. Results. There were 2,067 episodes of PJI diagnosed within the study period. A total of 3,629 fungal cultures and 2,923 mycobacterial cultures were performed, with at least one of these performed in 56% of episodes (n = 1,157). Test positivity rates of fungal and mycobacterial cultures were 5% (n = 179) and 1.2% (n = 34), respectively. After a comprehensive review, there were 40 true fungal and eight true mycobacterial PJIs. BCB were 90% sensitive in diagnosing true fungal PJI and 100% sensitive in detecting rapidly growing mycobacteria (RGM). Fungal stains were performed in 27 true fungal PJI but were only positive in four episodes (14.8% sensitivity). None of the mycobacterial stains was positive. Conclusion. Routine fungal and mycobacterial stains and cultures should not be performed as they have little clinical utility in the diagnosis of PJI and are associated with significant costs. Candida species and RGM are readily recovered using BCB. More research is needed to predict rare non-Candida fungal and slowly growing mycobacterial PJI that warrant specialized cultures. Cite this article: Bone Joint J 2022;104-B(1):53–58

Aims. Tert-butylhydroquinone (tBHQ) has been identified as an inhibitor of oxidative stress-induced injury and apoptosis in human neural stem cells. However, the role of tBHQ in osteoarthritis (OA) is unclear. This study was carried out to investigate the role of tBHQ in OA. Methods. OA animal model was induced by destabilization of the medial meniscus (DMM). Different concentrations of tBHQ (25 and 50 mg/kg) were intraperitoneally injected in ten-week-old female mice. Chondrocytes were isolated from articular cartilage of mice and treated with 5 ng/ml lipopolysaccharide (LPS) or 10 ng/ml interleukin 1 beta (IL-1β) for 24 hours, and then treated with different concentrations of tBHQ (10, 20, and 40 μM) for 12 hours. The expression levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in blood were measured. The expression levels of interleukin 6 (IL-6), IL-1β, and tumour necrosis factor alpha (TNF-α) leptin in plasma were measured using enzyme-linked immunoabsorbent assay (ELISA) kits. The expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathway proteins, and macrophage repolarization-related markers, were detected by western blot. Results. Tert-butylhydroquinone significantly attenuated cartilage destruction in DMM-induced mice in vivo. It demonstrated clear evidence of inhibiting IL-1β-induced chondrocyte apoptosis, inflammation, and differentiation defect in vitro. Meanwhile, tBHQ inhibited LPS-induced activation of NF-κB and MAPK signalling pathways, and also inhibited LPS-induced reactive oxygen species production and macrophages repolarization in vitro. Conclusion. Taken together, tBHQ might be a potential therapeutic strategy for protecting against OA development. Cite this article: Bone Joint Res 2021;10(11):704–713

Aims. Cell-free DNA (cfDNA) and circulating tumour DNA (ctDNA) are used for prognostication and monitoring in patients with carcinomas, but their utility is unclear in sarcomas. The objectives of this pilot study were to explore the prognostic significance of cfDNA and investigate whether tumour-specific alterations can be detected in the circulation of sarcoma patients. Methods. Matched tumour and blood were collected from 64 sarcoma patients (n = 70 samples) prior to resection of the primary tumour (n = 57) or disease recurrence (n = 7). DNA was isolated from plasma, quantified, and analyzed for cfDNA. A subset of cases (n = 6) underwent whole exome sequencing to identify tumour-specific alterations used to detect ctDNA using digital droplet polymerase chain reaction (ddPCR). Results. Cell-free was present in 69 of 70 samples above 0.5 ng/ml. Improved disease-free survival was found for patients with lower cfDNA levels (90% vs 48% at one-year for ≤ 6 ng/ml and > 6 ng/ml, respectively; p = 0.005). Digital droplet PCR was performed as a pilot study and mutant alleles were detectable at 0.5% to 2.5% of the wild type genome, and at a level of 0.25 ng tumour DNA. Tumour-specific alterations (ctDNA) were found in five of six cases. Conclusion. This work demonstrates the feasibility and potential utility of cfDNA and ctDNA as biomarkers for bone and soft-tissue sarcomas, despite the lack of recurrent genomic alterations. A larger study is required to validate these findings. Cite this article: Bone Joint Res 2021;10(9):602–610

Aims. The aim of this study was to investigate the hypothesis that a single dose of tranexamic acid (TXA) would reduce blood loss and transfusion rates in elderly patients undergoing surgery for a subcapital or intertrochanteric (IT) fracture of the hip. Methods. In this single-centre, randomized controlled trial, elderly patients undergoing surgery for a hip fracture, either hemiarthroplasty for a subcapital fracture or intramedullary nailing for an IT fracture, were screened for inclusion. Patients were randomly allocated to a study group using a sealed envelope. The TXA group consisted of 77 patients, (35 with a subcapital fracture and 42 with an IT fracture), and the control group consisted of 88 patients (29 with a subcapital fracture and 59 with an IT fracture). One dose of 15 mg/kg of intravenous (IV) TXA diluted in 100 ml normal saline (NS,) or one dose of IV placebo 100 ml NS were administered before the incision was made. The haemoglobin (Hb) concentration was measured before surgery and daily until the fourth postoperative day. The primary outcomes were the total blood loss and the rate of transfusion from the time of surgery to the fourth postoperative day. Results. Homogeneity with respect to baseline characteristics was ensured between groups. The mean total blood loss was significantly lower in patients who received TXA (902.4 ml (-279.9 to 2,156.9) vs 1,226.3 ml (-269.7 to 3,429.7); p = 0.003), while the likelihood of requiring a transfusion of at least one unit of red blood cells was reduced by 22%. Subgroup analysis showed that these differences were larger in patients who had an IT fracture compared with those who had a subcapital fracture. Conclusion. Elderly patients who undergo intramedullary nailing for an IT fracture can benefit from a single dose of 15 mg/kg TXA before the onset of surgery. A similar tendency was identified in patients undergoing hemiarthroplasty for a subcapital fracture but not to a statistically significant level. Cite this article: Bone Joint J 2021;103-B(3):442–448

Aims. A typical pattern of blood loss associated with total hip arthroplasty (THA) is 200 ml intraoperatively and 1.3 l in the first 48 postoperative hours. Tranexamic acid (TXA) is most commonly given as a single preoperative dose only and is often withheld from patients with a history of thromboembolic disease as they are perceived to be “high-risk” with respect to postoperative venous thromboembolism (VTE). The TRanexamic ACid for 24 hours trial (TRAC-24) aimed to identify if an additional 24-hour postoperative TXA regime could further reduce blood loss beyond a once-only dose at the time of surgery, without excluding these high-risk patients. Methods. TRAC-24 was a prospective, phase IV, single centre, open label, parallel group, randomized controlled trial (RCT) involving patients undergoing primary unilateral elective THA. The primary outcome measure was the indirect calculated blood loss (IBL) at 48 hours. The patients were randomized into three groups. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional oral regime for 24 hours postoperatively, group 2 only received the intraoperative dose, and group 3 did not receive any TXA. Results. A total of 534 patients were randomized, with 233 in group 1, 235 in group 2, and 66 in group 3; 92 patients (17.2%) were considered high-risk. The mean IBL did not differ significantly between the two intervention groups (848.4 ml (SD 463.8) for group 1, and 843.7 ml (SD 478.7) for group 2; mean difference -4.7 ml (95% confidence interval -82.9 to 92.3); p = 0.916). No differences in mortality or incidence of VTE were observed between any group. Conclusion. The addition of oral TXA for 24 hours postoperatively does not reduce blood loss beyond that achieved with a single 1 g IV perioperative dose alone. There may be a clinically relevant difference in patients with a normal BMI, which warrants further investigation. Critically, there were no safety issues in patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease. Cite this article: Bone Joint J 2021;103-B(7):1197–1205

Objectives. Indocyanine green (ICG) fluorescence angiography is an emerging technique that can provide detailed anatomical information during surgery. The purpose of this study is to determine whether ICG fluorescence angiography can be used to evaluate the blood flow of the rotator cuff tendon in the clinical setting. Methods. Twenty-six patients were evaluated from October 2016 to December 2017. The participants were categorized into three groups based on their diagnoses: the rotator cuff tear group; normal rotator cuff group; and adhesive capsulitis group. After establishing a posterior standard viewing portal, intravenous administration of ICG at 0.2 mg/kg body weight was performed, and fluorescence images were recorded. The time from injection of the drug to the beginning of enhancement of the observed area was measured. The hypovascular area in the rotator cuff was evaluated, and the ratio of the hypovascular area to the anterolateral area of the rotator cuff tendon was calculated (hypovascular area ratio). Results. ICG fluorescence angiography allowed for visualization of blood flow in the rotator cuff in all groups. The adhesive capsulitis group showed significantly earlier enhancement than the other groups. Furthermore, the adhesive capsulitis group had a significantly smaller hypovascular area ratio than the other groups. Conclusion. ICG fluorescence angiography allowed for evaluation of real-time blood flow of the rotator cuff in arthroscopic shoulder surgery. The techniques of ICG fluorescence angiography are simple and easy to observe, observer reliability is high, and it has utility for evaluating blood flow during surgery. Cite this article: N. Doi, T. Izaki, S. Miyake, T. Shibata, T. Ishimatsu, Y. Shibata, T. Yamamoto. Intraoperative evaluation of blood flow for soft tissues in orthopaedic surgery using indocyanine green fluorescence angiography: A pilot study. Bone Joint Res 2019;8:118–125. DOI: 10.1302/2046-3758.83.BJR-2018-0151.R1

Aims. The aim of this study was to evaluate blood metal ion levels, leucocyte profiles, and serum cytokines in patients with a total hip arthroplasty (THA) involving modular dual-mobility components. Patients and Methods. A total of 39 patients were recruited, with clinical follow-up of up to two years. Outcome was assessed using the Harris Hip Score (HHS, the 12-Item Short-Form Health Survey (SF-12), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a visual analogue scale (VAS) for pain. Blood concentrations of cobalt (Co), chromium (Cr), and serum cytokines were measured. Subpopulations of leucocytes were analyzed by flow cytometry. Results. The clinical performance was good. Blood Co levels (ref 1.0 µg/l) were mildly elevated in seven patients at three months, and two patients at two years’ follow-up. The preoperative Cr levels were normal except for one patient with a detectable Cr (1.2 µg/l). Cr levels were detectable in three patients at three months, two patients at one year, and three patients at two years’ follow-up. No patients had symptoms suggestive of failure. Although flow cytometry showed constant circulating leucocyte profiles, there was a significant reduction of serum interleukin (IL)-4, IL-5, and interferon gamma (IFNγ) postoperatively compared with the preoperative levels (p < 0.05). Conclusion. These results suggest that THA using modular dual-mobility components is safe. This allows an opportunity to use a large femoral head and a thick polyethylene bearing surface, which is especially useful in revision procedures or high-risk situations when added stability is required. Cite this article: Bone Joint J 2019;101-B:1035–1041

Aims. The purpose of the present study was to evaluate the impact of intravenous tranexamic acid on the reduction of blood loss, transfusion rate, and early post-operative clinical outcome in total shoulder arthroplasty. Patients and Methods. A randomised, placebo-controlled trial which included 54 patients undergoing unilateral primary stemless anatomical or stemmed reverse total shoulder arthroplasty was undertaken. Patients received either 100 ml saline (placebo, n = 27), or 100 ml saline together with 1000 mg of tranexamic acid (TXA, n = 27) intravenously prior to skin incision and during wound closure. Peri-operative blood loss via an intra-articular drain was recorded and total blood loss was calculated. The post-operative transfusion rate was documented. Assessment of early clinical parameters included the visual analogue scale for pain (VAS), documentation of haematoma formation and adverse events. Results. Mean peri-operative blood drainage (placebo: 170 ml versus TXA: 50 ml, p = 0.001) and calculated mean total blood loss (placebo: 1248.2 ml versus TXA: 871.0 ml, p = 0.009) were significantly lower in the TXA group. No transfusions were necessary during the study period in either group. Mean VAS for pain significantly decreased from pre-operative (VAS 7) to the early post-operative period (VAS 1.7, p < 0.001). Significant differences regarding mean post-operative pain between placebo (VAS 2.0) and TXA (VAS 1.3) were detected (p = 0.05). The occurrence of haematomas was significantly more frequent in the placebo (59.3%, n = 16) than in the TXA group (25.9%, n = 6, p = 0.027). Whereas only mild haematomas developed in the TXA group, in the placebo group a total of 22.2% (n = 6) developed either moderate or severe haematomas. No adverse events associated with administration of TXA occurred. Conclusion. Intravenous administration of TXA successfully reduced mean peri-operative blood drainage, total estimated blood loss, pain during the first post-operative days, and haematoma formation in total shoulder arthroplasty. Cite this article: Bone Joint J 2017;99-B:1073–9

Blood loss during total knee replacement (TKR) remains a significant concern. In this study, 114 patients underwent TKR, and were divided into two groups based on whether they received a new generation fibrin sealant intra-operatively, or a local infiltration containing adrenaline. Groups were then compared for mean calculated total blood volume (TBV) loss, transfusion rates, and knee range of movement. Mean TBV loss was similar between groups: fibrin sealant mean was 705 ml (281 to 1744), local adrenaline mean was 712 ml (261 to 2308) (p = 0.929). Overall, significantly fewer units of blood were transfused in the fibrin sealant group (seven units) compared with the local adrenaline group (15 units) (p = 0.0479). Per patient transfused, significantly fewer units of blood were transfused in the fibrin sealant group (1.0 units) compared with the local adrenaline group (1.67 units) (p = 0.027), suggesting that the fibrin sealant may reduce the need for multiple unit transfusions. Knee range of movement was similar between groups. From our results, it appears that application of this newer fibrin sealant results in blood loss and transfusion rates that are low and similar to previously applied fibrin sealants. Cite this article: Bone Joint J 2013;95-B, Supple A:135–9

We carried out a prospective randomised study to evaluate the blood loss in 60 patients having a total knee arthroplasty and divided randomly into two equal groups, one having a computer-assisted procedure and the other a standard operation. The surgery was carried out by a single surgeon at one institution using a uniform approach. The only variable in the groups was the use of intramedullary femoral and tibial alignment jigs in the standard group and single tracker pins of the imageless navigation system in the tibia and femur in the navigated group. The mean drainage of blood was 1351 ml (715 to 2890; 95% confidence interval (CI) 1183 to 1518) in the computer-aided group and 1747 ml (1100 to 3030; CI 1581 to 1912) in the conventional group. This difference was statistically significant (p = 0.001). The mean calculated loss of haemoglobin was 36 g/dl in the navigated group versus 53 g/dl in the conventional group; this was significant at p < 0.00001. There was a highly significant reduction in blood drainage and the calculated Hb loss between the computer-assisted and the conventional techniques. This allows the ordering of less blood before the operation, reduces risks at transfusion and gives financial saving. Computer-assisted surgery may also be useful for patients in whom blood products are not acceptable

Clinical, haematological or economic benefits of post-operative blood salvage with autologous blood re-transfusion have yet to be clearly demonstrated for primary total hip replacement. We performed a prospective randomised study to analyse differences in postoperative haemoglobin levels and homologous blood requirements in two groups of patients undergoing primary total hip replacement. A series of 158 patients was studied. In one group two vacuum drains were used and in the other the ABTrans autologous retransfusion system. A total of 58 patients (76%) in the re-transfusion group received autologous blood. There was no significant difference in the mean post-operative haemoglobin levels in the two groups. There were, however, significantly fewer patients with post-operative haemoglobin values less than 9.0 g/dl and significantly fewer patients who required transfusion of homologous blood in the re-transfusion group. There was also a small overall cost saving in this group

Aims

The primary aim of this study was to assess the feasibility of recruiting and retaining patients to a patient-blinded randomized controlled trial comparing corticosteroid injection (CSI) to autologous protein solution (APS) injection for the treatment of subacromial shoulder pain in a community care setting. The study focused on recruitment rates and retention of participants throughout, and collected data on the interventions’ safety and efficacy.

There is currently no consensus about the mean volume of blood lost during spinal tumour surgery and surgery for metastatic spinal disease. We conducted a systematic review of papers published in the English language between 31 January 1992 and 31 January 2012. Only papers that clearly presented blood loss data in spinal surgery for metastatic disease were included. The random effects model was used to obtain the pooled estimate of mean blood loss. We selected 18 papers, including six case series, ten retrospective reviews and two prospective studies. Altogether, there were 760 patients who had undergone spinal tumour surgery and surgery for metastatic spinal disease. The pooled estimate of peri-operative blood loss was 2180 ml (95% confidence interval 1805 to 2554) with catastrophic blood loss as high as 5000 ml, which is rare. Aside from two studies that reported large amounts of mean blood loss (> 5500 ml), the resulting funnel plot suggested an absence of publication bias. This was confirmed by Egger’s test, which did not show any small-study effects (p = 0.119). However, there was strong evidence of heterogeneity between studies (I. 2. = 90%; p < 0.001). Spinal surgery for metastatic disease is associated with significant blood loss and the possibility of catastrophic blood loss. There is a need to establish standardised methods of calculating and reporting this blood loss. Analysis should include assessment by area of the spine, primary pathology and nature of surgery so that the amount of blood loss can be predicted. Consideration should be given to autotransfusion in these patients. Cite this article: Bone Joint J 2013;95-B:683–8

Objectives. The objective of this study was to investigate the therapeutic effect of peripheral blood mononuclear cells (PBMNCs) treated with quality and quantity control culture (QQ-culture) to expand and fortify angiogenic cells on the acceleration of fracture healing. Methods. Human PBMNCs were cultured for seven days with the QQ-culture method using a serum-free medium containing five specific cytokines and growth factors. The QQ-cultured PBMNCs (QQMNCs) obtained were counted and characterised by flow cytometry and real-time polymerase chain reaction (RT-PCR). Angiogenic and osteo-inductive potentials were evaluated using tube formation assays and co-culture with mesenchymal stem cells with osteo-inductive medium in vitro. In order to evaluate the therapeutic potential of QQMNCs, cells were transplanted into an immunodeficient rat femur nonunion model. The rats were randomised into three groups: control; PBMNCs; and QQMNCs. The fracture healing was evaluated radiographically and histologically. Results. The total number of PBMNCs was decreased after QQ-culture, however, the number of CD34+ and CD206+ cells were found to have increased as assessed by flow cytometry analysis. In addition, gene expression of angiogenic factors was upregulated in QQMNCs. In the animal model, the rate of bone union was higher in the QQMNC group than in the other groups. Radiographic scores and bone volume were significantly associated with the enhancement of angiogenesis in the QQMNC group. Conclusion. We have demonstrated that QQMNCs have superior potential to accelerate fracture healing compared with PBMNCs. The QQMNCs could be a promising option for fracture nonunion. Cite this article: K. Mifuji, M. Ishikawa, N. Kamei, R. Tanaka, K. Arita, H. Mizuno, T. Asahara, N. Adachi, M. Ochi. Angiogenic conditioning of peripheral blood mononuclear cells promotes fracture healing. Bone Joint Res 2017;6: 489–498. DOI: 10.1302/2046-3758.68.BJR-2016-0338.R1

Our aim was to determine the total blood loss associated with surgery for fracture of the hip and to identify risk factors for increased blood loss. We prospectively studied 546 patients with hip fracture. The total blood loss was calculated on the basis of the haemoglobin difference, the number of transfusions and the estimated blood volume. The hidden blood loss, in excess of that observed during surgery, varied from 547 ml (screws/ pins) to 1473 ml (intramedullary hip nail and screw) and was significantly associated with medical complications and increased hospital stay. The type of surgery, treatment with aspirin, intra-operative hypotension and gastro-intestinal bleeding or ulceration were all independent predictors of blood loss. We conclude that total blood loss after surgery for hip fracture is much greater than that observed intra-operatively. Frequent post-operative measurements of haemoglobin are necessary to avoid anaemia

Aims. Currently, there is little information about the need for peri-operative blood transfusion in patients undergoing shoulder arthroplasty. . The purpose of this study was to identify the rate of transfusion and its predisposing factors, and to establish a blood conservation strategy. . Methods. We identified all patients who had undergone shoulder arthroplasty at our hospital between 1 January 2011 and 31 December 2013. The rate of transfusion was determined from the patient’s records. While there were exceptions, patients typically underwent transfusion if they had a level of haemoglobin of < 7.5 g/dl if asymptomatic, < 9.0 g/dl if they had a significant cardiac history or symptoms of dizziness or light headedness. . Multivariable regression analysis was undertaken to identify predictors of transfusion. High- and low-risk cohorts for transfusion were identified from a receiver operating characteristic (ROC) curve. Results. Of 1174 shoulder arthroplasties performed on 1081 patients, 53 cases (4.5%) required transfusion post-operatively. Predictors of blood transfusion were a lower pre-operative haematocrit (p < 0.001) and shoulder arthroplasty undertaken for post-traumatic arthritis (p < 0.001). ROC analysis identified pre-operative haematocrit of 39.6% as a 90% sensitivity cut-off for transfusion. In total 48 of the 436 (11%) shoulder arthroplasties with a pre-operative haematocrit < 39.6% needed transfusion compared with five of the 738 (0.70%) shoulder arthroplasties with a haematocrit above this level. . Discussion . We found that transfusion was needed less frequently than previously described for shoulder arthroplasty. Patients with a pre-operative haematocrit < 39.6% should be advised that there is an increased risk for blood transfusion, while those with a haematocrit above this level are unlikely to require transfusion. . Take home message: The rate of transfusion after shoulder arthroplasty is under 5%, and those with a pre-operative haematocrit greater than or equal to 39.6% have a very low likelihood (< 1%) of requiring a transfusion. Cite this article: Bone Joint J 2016;98-B:224–8

Tranexamic acid is a fibrinolytic inhibitor which reduces blood loss in total knee replacement. We examined the effect on blood loss of a standardised intravenous bolus dose of 1 g of tranexamic acid, given at the induction of anaesthesia in patients undergoing total hip replacement and tested the potential prothrombotic effect by undertaking routine venography. In all, 36 patients received 1 g of tranexamic acid, and 37 no tranexamic acid. Blood loss was measured directly per-operatively and indirectly post-operatively. Tranexamic acid reduced the early post-operative blood loss and total blood loss (p = 0.03 and p = 0.008, respectively) but not the intraoperative blood loss. The tranexamic acid group required fewer transfusions (p = 0.03) and had no increased incidence of deep-vein thrombosis. The reduction in early post-operative blood loss was more marked in women (p = 0.05), in whom this effect was dose-related (r = −0.793). Our study showed that the administration of a standardised pre-operative bolus of 1 g of tranexamic acid was cost-effective in reducing the blood loss and transfusion requirements after total hip replacement, especially in women

Objectives. The aims of this piece of work were to: 1) record the background concentrations of blood chromium (Cr) and cobalt (Co) concentrations in a large group of subjects; 2) to compare blood/serum Cr and Co concentrations with retrieved metal-on-metal (MoM) hip resurfacings; 3) to examine the distribution of Co and Cr in the serum and whole blood of patients with MoM hip arthroplasties; and 4) to further understand the partitioning of metal ions between the serum and whole blood fractions. Methods. A total of 3042 blood samples donated to the local transfusion centre were analysed to record Co and Cr concentrations. Also, 91 hip resurfacing devices from patients who had given pre-revision blood/serum samples for metal ion analysis underwent volumetric wear assessment using a coordinate measuring machine. Linear regression analysis was carried out and receiver operating characteristic curves were constructed to assess the reliability of metal ions to identify abnormally wearing implants. The relationship between serum and whole blood concentrations of Cr and Co in 1048 patients was analysed using Bland-Altman charts. This relationship was further investigated in an in vitro study during which human blood was spiked with trivalent and hexavalent Cr, the serum then separated and the fractions analysed. Results. Only one patient in the transfusion group was found to have a blood Co > 2 µg/l. Blood/Serum Cr and Co concentrations were reliable indicators of abnormal wear. Blood Co appeared to be the most useful clinical test, with a concentration of 4.5 µg/l showing sensitivity and specificity for the detection of abnormal wear of 94% and 95%, respectively. Generated metal ions tended to fill the serum compartment preferentially in vivo and this was replicated in the in vitro study when blood was spiked with trivalent Cr and bivalent Co. Conclusions. Blood/serum metal ion concentrations are reliable indicators of abnormal wear processes. Important differences exist however between elements and the blood fraction under study. Future guidelines must take these differences into account

Aims. Cementless primary total hip arthroplasty (THA) is associated with risks of bleeding and thromboembolism. Anticoagulants are effective as venous thromboprophylaxis, but with an increased risk of bleeding. Tranexamic acid (TXA) is an efficient antifibrinolytic agent, but the mode and timing of its administration remain controversial. This study aimed to determine whether two intravenous (IV) TXA regimens (a three-hour two-dose (short-TXA) and 11-hour four-dose (long-TXA)) were more effective than placebo in reducing perioperative real blood loss (RBL, between baseline and day 3 postoperatively) in patients undergoing THA who receive rivaroxaban as thromboprophylaxis. The secondary aim was to assess the non-inferiority of the reduction of blood loss of the short protocol versus the long protocol. Patients and Methods. A multicentre, prospective, randomized, double-blind, placebo-controlled trial was undertaken involving 229 patients undergoing primary cementless THA using a posterior approach, whose extended rivaroxaban thromboprophylaxis started on the day of surgery. There were 98 male and 131 female patients, with a mean age of 65.5 years (32 to 91). The primary outcome, perioperative RBL, was evaluated at 72 hours postoperatively. The efficacy of short- and long-TXA protocols in the reduction of perioperative RBL was compared with a placebo group. Results. TXA significantly reduced perioperative blood loss compared with placebo (p < 0.001); the mean differences were 525.3 ml (short-TXA vs placebo) and 550.1 ml (long-TXA vs placebo). No venous or arterial thromboembolic complications were reported. The upper boundary of the 95% confidence interval, when comparing short and long protocols, was below the pre-specified margin of non-inferiority (p = 0.027). Conclusion. In patients undergoing primary cementless THA, using a posterior approach, who are treated with rivaroxaban for thromboembolic prophylaxis, short- and long-TXA IV protocols are significantly more effective than placebo in reducing perioperative RBL, without any thromboembolic complications. Non-inferiority of a short- versus a long-TXA protocol in reducing perioperative RBL was supported in a secondary analysis

There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available hip resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) hip resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p < 0.05). Cr and Co were more strongly influenced by the position of the acetabular component in the case of the ASR, with an increase in metal ions observed at inclinations > 45° and anteversion angles of < 10° and > 20°. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55°. A significant relationship was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p < 0.05 for Co), with an increase observed at anteversion angles < 10° and > 20°. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p < 0.001). This indicates that reduced diametral clearance may equate to a reduction in metal ion concentrations in larger joints with satisfactory orientation of the acetabular component

Aims. The aim of this study was to determine the diagnostic accuracy of α defensin (AD) lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) tests for periprosthetic joint infection (PJI) in comparison to conventional synovial white blood cell (WBC) count and polymorphonuclear neutrophil percentage (PMN%) analysis. Methods. Patients undergoing joint aspiration for evaluation of pain after total knee arthroplasty (TKA) or total hip arthroplasty (THA) were considered for inclusion. Synovial fluids from 99 patients (25 THA and 74 TKA) were analyzed by WBC count and PMN% analysis, AD LFA, and AD ELISA. WBC and PMN% cutoffs of ≥ 1,700 cells/mm. 3. and ≥ 65% for TKA and ≥ 3,000 cells/mm. 3. and ≥ 80% for THA were used, respectively. A panel of three physicians, all with expertise in orthopaedic infections and who were blinded to the results of AD tests, independently reviewed patient data to diagnose subjects as with or without PJI. Consensus PJI classification was used as the reference standard to evaluate test performances. Results were compared using McNemar’s test and area under the receiver operating characteristic curve (AUC) analysis. Results. Expert consensus classified 18 arthroplasies as having failed due to PJI and 81 due to aseptic failure. Using these classifications, the calculated sensitivity and specificity of AD LFA was 83.3% (95% confidence interval (CI) 58.6 to 96.4) and 93.8% (95% CI 86.2 to 98.0), respectively. Sensitivity and specificity of AD ELISA was 83.3% (95% CI 58.6 to 96.4) and 96.3% (95% CI 89.6 to 99.2), respectively. There was no statistically significant difference between sensitivity (p = 1.000) or specificity (p = 0.157) of the two AD assays. AUC for AD LFA was 0.891. In comparison, AUC for synovial WBC count, PMN%, and the combination of the two values was 0.821 (sensitivity p = 1.000, specificity p < 0.001), 0.886 (sensitivity p = 0.317, specificity p = 0.011), and 0.926 (sensitivity p = 0.317, specificity p = 0.317), respectively. Conclusion. The diagnostic accuracy of synovial AD for PJI diagnosis is comparable and not statistically superior to that of synovial WBC count plus PMN% combined. Cite this article: Bone Joint J 2021;103-B(6):1119–1126

Objectives. Alarm over the reported high failure rates for metal-on-metal (MoM) hip implants as well as their potential for locally aggressive Adverse Reactions to Metal Debris (ARMDs) has prompted government agencies, internationally, to recommend the monitoring of patients with MoM hip implants. Some have advised that a blood ion level >7 µg/L indicates potential for ARMDs. We report a systematic review and meta-analysis of the performance of metal ion testing for ARMDs. Methods. We searched MEDLINE and EMBASE to identify articles from which it was possible to reconstruct a 2 × 2 table. Two readers independently reviewed all articles and extracted data using explicit criteria. We computed a summary receiver operating curve using a Bayesian random-effects hierarchical model. Results. Our literature search returned 575 unique articles; only six met inclusion criteria defined a priori. The discriminative capacity of ion tests was homogeneous across studies but that there was substantial cut-point heterogeneity. Our best estimate of the “true” area under curve (AUC) for metal ion testing is 0.615, with a 95% credible interval of 0.480 to 0.735, thus we can state that the probability that metal ion testing is actually clinically useful with an AUC ≥ 0.75 is 1.7%. Conclusion. Metal ion levels are not useful as a screening test for identifying high risk patients because ion testing will either lead to a large burden of false positive patients, or otherwise marginally modify the pre-test probability. With the availability of more accurate non-invasive tests, we did not find any evidence for using blood ion levels to diagnose symptomatic patients. Cite this article: M. Pahuta, J. M. Smolders, J. L. van Susante, J. Peck, P. R. Kim, P. E. Beaule. Blood metal ion levels are not a useful test for adverse reactions to metal debris: a systematic review and meta-analysis. Bone Joint Res 2016;5:379–386. DOI: 10.1302/2046-3758.59.BJR-2016-0027.R1

Objectives. Adipose-derived mesenchymal stem cells (ADMSCs) are a promising strategy for orthopaedic applications, particularly in bone repair. Ex vivo expansion of ADMSCs is required to obtain sufficient cell numbers. Xenogenic supplements should be avoided in order to minimise the risk of infections and immunological reactions. Human platelet lysate and human plasma may be an excellent material source for ADMSC expansion. In the present study, use of blood products after their recommended transfusion date to prepare human platelet lysate (HPL) and human plasma (Hplasma) was evaluated for in vitro culture expansion and osteogenesis of ADMSCs. Methods. Human ADMSCs were cultured in medium supplemented with HPL, Hplasma and a combination of HPL and Hplasma (HPL+Hplasma). Characteristics of these ADMSCs, including osteogenesis, were evaluated in comparison with those cultured in fetal bovine serum (FBS). Results. HPL and HPL+Hplasma had a significantly greater growth-promoting effect than FBS, while Hplasma exhibited a similar growth-promoting effect to that of FBS. ADMSCs cultured in HPL and/or Hplasma generated more colony-forming unit fibroblasts (CFU-F) than those cultured in FBS. After long-term culture, ADMSCs cultured in HPL and/or Hplasma showed reduced cellular senescence, retained typical cell phenotypes, and retained differentiation capacities into osteogenic and adipogenic lineages. Conclusion. HPL and Hplasma prepared from blood products after their recommended transfusion date can be used as an alternative and effective source for large-scale ex vivo expansion of ADMSCs. Cite this article: J. Phetfong, T. Tawonsawatruk, K. Seenprachawong, A. Srisarin, C. Isarankura-Na-Ayudhya, A. Supokawej. Re-using blood products as an alternative supplement in the optimisation of clinical-grade adipose-derived mesenchymal stem cell culture. Bone Joint Res 2017;6:414–422. DOI: 10.1302/2046-3758.67.BJR-2016-0342.R1

Objectives. Tranexamic acid (TXA) is an antifibrinolytic agent used as a blood-sparing technique in total knee arthroplasty (TKA), and is routinely administered by intravenous (IV) or intra-articular (IA) injection. Recently, a novel method of TXA administration, the combined IV and IA application of TXA, has been applied in TKA. However, the scientific evidence of combined administration of TXA in TKA is still meagre. This meta-analysis aimed to investigate the efficacy and safety of combined IV and IA TXA in patients undergoing TKA. Materials and Methods. A systematic search was carried out in PubMed, the Cochrane Clinical Trial Register (Issue12 2015), Embase, Web of Science and the Chinese Biomedical Database. Only randomised controlled trials (RCT) evaluating the efficacy and safety of combined use TXA in TKA were identified. Two authors independently identified the eligible studies, extracted data and assessed the methodological quality of included studies. Meta-analysis was conducted using Review Manager 5.3 software. Results. A total of ten RCTs (1143 patients) were included in this study. All the included studies were randomised and the quality of included studies still needed improvement. The results indicated that, compared with either placebo or the single-dose TXA (IV or IA) group, the combination of IV and IA TXA group had significantly less total blood loss, hidden blood loss, total drain output, a lower transfusion rate and a lower drop in haemoglobin level. There were no statistically significant differences in complications such as wound infection and deep vein thrombosis between the combination group and the placebo or single-dose TXA group. Conclusions. Compared with placebo or the single-dose TXA, the combined use of IV and IA TXA provided significantly better results with respect to all outcomes related to post-operative blood loss without increasing the risk of thromboembolic complications in TKA. Cite this article: Z. F. Yuan, H. Yin, W. P. Ma, D. L. Xing. The combined effect of administration of intravenous and topical tranexamic acid on blood loss and transfusion rate in total knee arthroplasty: combined tranexamic acid for TKA. Bone Joint Res 2016;5:353–361. DOI: 10.1302/2046-3758.58.BJR-2016-0001.R2

Aims. Our first aim was to determine whether there are significant changes in the level of metal ions in the blood at mid-term follow-up, in patients with an Articular Surface Replacement (ASR) arthroplasty. Secondly, we sought to identify risk factors for any increases. Patients and Methods. The study involved 435 patients who underwent unilateral, metal-on-metal (MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). These patients all had one measurement of the level of metal ions in the blood before seven years had passed post-operatively (early evaluation) and one after seven years had passed post-operatively (mid-term evaluation). Changes in ion levels were tested using a Wilcoxon signed-rank test. We identified subgroups at the highest risk of increase using a multivariable linear logistic regression model. Results. There were significant increases in the levels of metal ions for patients who underwent both MoM HRA (Chromium (Cr): 0.5 parts per billion (ppb); Cobalt (Co): 1.1 ppb) and MoM THA (Cr: 0.5 ppb; Co: 0.7 ppb). In a multivariable model considering MoM HRAs, the change in the levels of metal ions was influenced by female gender (Co: Odds Ratio (OR) 1.42; p = 0.002 and Cr: OR 1.08; p = 0.006). The change was found to be irrespective of the initial level for the MoM HRAs, whereas there was a negative relationship between the initial level and the change in the level for those with a MoM THA (Co: OR -0.43; p <  0.001 and Cr: OR -0.14; p = 0.033). Conclusion. The levels of metal ions in the blood increase significantly over the period until mid-term follow-up in patients with both a MoM HRA and those with a MoM THA. We recommend that the levels of metal ions be measured most frequently for women with a MoM HRA. While those with a MoM THA appear to stabilise at a certain level, the accuracy of this trend is not yet clear. Vigilant follow-up is still recommended. . Cite this article: Bone Joint J 2017;99-B(4 Supple B):33–40

Tranexamic acid (TXA), an inhibitor of fibrinolysis, reduces blood loss after total knee arthroplasty. However, its effect on minimally invasive total hip arthroplasty (THA) is not clear. We performed a prospective, randomised double-blind study to evaluate the effect of two intravenous injections of TXA on blood loss in patients undergoing minimally invasive THA. In total, 60 patients (35 women and 25 men with a mean age of 58.1 years; 17 to 84) who underwent unilateral minimally invasive uncemented THA were randomly divided into the study group (30 patients, 20 women and ten men with a mean age of 56.5 years; 17 to 79) that received two intravenous injections 1 g of TXA pre- and post-operatively (TXA group), and a placebo group (30 patients, 15 women and 15 men with a mean age of 59.5 years; 23 to 84). We compared the peri-operative blood loss of the two groups. Actual blood loss was calculated from the maximum reduction in the level of haemoglobin. All patients were followed clinically for the presence of venous thromboembolism. The TXA group had a lower mean intra-operative blood loss of 441 ml (150 to 800) versus 615 ml (50 to 1580) in the placebo (p = 0.044), lower mean post-operative blood loss (285 ml (120 to 570) versus 392 ml (126 to 660) (p = 0.002), lower mean total blood loss (1070 ml (688 to 1478) versus 1337 ml (495 to 2238) (p = 0.004) and lower requirement for transfusion (p = 0.021). No patients in either group had symptoms of venous thromboembolism or wound complications. . This prospective, randomised controlled study showed that a regimen of two intravenous injections of 1 g TXA is effective for blood conservation after minimally invasive THA. Cite this article: Bone Joint J 2015;97-B:905–10

We studied 70 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery. They were divided into two groups. In the study group of 38 patients one or more modern blood-conservation measures was used peri-operatively. The 32 patients in the control group did not have these measures. Both groups were similar in regard to age, body-weight, the number of levels fused and the type of surgery. Only two patients in the study group were transfused with homologous blood and these transfusions were ‘off-protocol’. Wastage of autologous pre-donated units was minimal (6 of 83 units). By contrast, all patients in the control group were transfused with homologous blood. In the study group there was a significant decrease (p = 0.005) in the estimated blood loss when all the blood-conservation methods were used. The use of blood-conservation measures, the lowering of the haemoglobin trigger for transfusion and the education of the entire team involved in the care of the patient can prevent the need for homologous blood transfusion in patients undergoing surgery for adolescent idiopathic scoliosis

Several aspects of the management of an orthopaedic surgical patient are not directly related to the surgical technique but are nevertheless essential for a successful outcome. Blood management is one of these. This paper considers the various strategies available for the management of blood loss in patients undergoing orthopaedic and trauma surgery

Despite advances in contemporary hip and knee arthroplasty, blood loss continues to be an issue. Though blood transfusion has long been used to treat post-operative anemia, the associated risks are well established. The objective of this article is to present two practical and effective approaches to minimising blood loss and transfusion rates in hip and knee arthroplasty: the use of antifibrinolytic medications such as tranexamic acid and the adoption of more conservative transfusion indications

In an initial randomised controlled trial (RCT) we segregated 180 patients to one of two knee positions following total knee replacement (TKR): six hours of knee flexion using either a jig or knee extension. Outcome measures included post-operative blood loss, fall in haemoglobin, blood transfusion requirements, knee range of movement, limb swelling and functional scores. A second RCT consisted of 420 TKR patients randomised to one of three post-operative knee positions: flexion for three or six hours post-operatively, or knee extension. Positioning of the knee in flexion for six hours immediately after surgery significantly reduced blood loss (p = 0.002). There were no significant differences in post-operative range of movement, swelling, pain or outcome scores between the various knee positions in either study. Post-operative knee flexion may offer a simple and cost-effective way to reduce blood loss and transfusion requirements following TKR. We also report a cautionary note regarding the potential risks of prolonged knee flexion for more than six hours observed during clinical practice in the intervening period between the two trials, with 14 of 289 patients (4.7%) reporting lower limb sensory neuropathy at their three-month review. Cite this article: Bone Joint J 2014;96-B:201–9

We investigated the blood supply of the common peroneal nerve. Dissection of 19 lower limbs, including six with intra-vascular injection of latex, allowed gross and microscopic measurements to be made of the blood supply of the common peroneal nerve in the popliteal fossa. This showed that a long segment of the nerve in the vicinity of the fibular neck contained only a few intraneural vessels of fine calibre. By contrast, the tibial nerve received an abundant supply from a constant series of vessels arising directly from the popliteal and posterior tibial arteries. The susceptibility of the common peroneal nerve to injury from a variety of causes and its lack of response to operative treatment may be explained by the tenuous nature of its intrinsic blood supply

The femoral head receives blood supply mainly from the deep branch of the medial femoral circumflex artery (MFCA). In previous studies we have performed anatomical dissections of 16 specimens and subsequently visualised the arteries supplying the femoral head in 55 healthy individuals. In this further radiological study we compared the arterial supply of the femoral head in 35 patients (34 men and one woman, mean age 37.1 years (16 to 64)) with a fracture/dislocation of the hip with a historical control group of 55 hips. Using CT angiography, we identified the three main arteries supplying the femoral head: the deep branch and the postero-inferior nutrient artery both arising from the MFCA, and the piriformis branch of the inferior gluteal artery. It was possible to visualise changes in blood flow after fracture/dislocation. Our results suggest that blood flow is present after reduction of the dislocated hip. The deep branch of the MFCA was patent and contrast-enhanced in 32 patients, and the diameter of this branch was significantly larger in the fracture/dislocation group than in the control group (p = 0.022). In a subgroup of ten patients with avascular necrosis (AVN) of the femoral head, we found a contrast-enhanced deep branch of the MFCA in eight hips. Two patients with no blood flow in any of the three main arteries supplying the femoral head developed AVN. Cite this article: Bone Joint J 2013;95-B:1453–7

We used Laser Doppler flowmetry to measure the effect on the blood flow to the femoral head/neck junction of two surgical approaches during resurfacing arthroplasty. We studied 24 hips undergoing resurfacing arthroplasty for osteoarthritis. Of these, 12 had a posterior approach and 12 a trochanteric flip approach. A Laser probe was placed under radiological control in the superolateral part of the femoral head/neck junction. The Doppler flux was measured at stages of the operation and compared with the initial flux. In both groups the main fall in blood flow occurred during the initial exposure and capsulotomy of the hip joint. There was a greater reduction in blood flow with the posterior (40%) than with the trochanteric flip approach (11%)

Blood metal ions have been widely used to investigate metal-on-metal hip replacements, but their ability to discriminate between well-functioning and failed hips is not known. The Medicines and Healthcare products Regulatory Agency (MHRA) has suggested a cut-off level of 7 parts per billion (ppb). We performed a pair-matched, case-control study to investigate the sensitivity and specificity of blood metal ion levels for diagnosing failure in 176 patients with a unilateral metal-on-metal hip replacement. We recruited 88 cases with a pre-revision, unexplained failed hip and an equal number of matching controls with a well-functioning hip. We investigated the 7 ppb cut-off level for the maximum of cobalt or chromium and determined optimal mathematical cut-off levels from receiver-operating characteristic curves. The 7 ppb cut-off level for the maximum of cobalt or chromium had a specificity of 89% and sensitivity 52% for detecting a pre-operative unexplained failed metal on metal hip replacement. The optimal cut-off level for the maximum of cobalt or chromium was 4.97 ppb and had sensitivity 63% and specificity 86%. Blood metal ions had good discriminant ability to separate failed from well-functioning hip replacements. The MHRA cut-off level of 7 ppb provides a specific test but has poor sensitivity.

Aims. We investigated whether blood metal ion levels could effectively identify patients with bilateral Birmingham Hip Resurfacing (BHR) implants who have adverse reactions to metal debris (ARMD). Patients and Methods. Metal ion levels in whole blood were measured in 185 patients with bilateral BHRs. Patients were divided into those with ARMD who either had undergone a revision for ARMD or had ARMD on imaging (n = 30), and those without ARMD (n = 155). Receiver operating characteristic analysis was used to determine the optimal thresholds of blood metal ion levels for identifying patients with ARMD. Results. The maximum level of cobalt or chromium ions in the blood was the parameter which produced the highest area under the curve (91.0%). The optimal threshold for distinguishing between patients with and without ARMD was 5.5 µg/l (83.3% sensitivity, 88.4% specificity, 58.1% positive and 96.5% negative predictive values). Similar results were obtained in a subgroup of 111 patients who all underwent cross-sectional imaging. Between 3.2% and 4.3% of patients with ARMD were missed if United Kingdom (7 µg/l) and United States (10 µg/l) authority thresholds were used respectively, compared with 2.7% if our implant specific threshold was used, though these differences did not reach statistical significance (p ≥ 0.248). Conclusion. Patients with bilateral BHRs who have blood metal ion levels below our implant specific threshold were at low-risk of having ARMD. Cite this article: Bone Joint J 2016;98-B:1455–62

Objectives. Local corticosteroid infiltration is a common practice of treatment for lateral epicondylitis. In recent studies no statistically significant or clinically relevant results in favour of corticosteroid injections were found. The injection of autologous blood has been reported to be effective for both intermediate and long-term outcomes. It is hypothesised that blood contains growth factors, which induce the healing cascade. Methods. A total of 60 patients were included in this prospective randomised study: 30 patients received 2 ml autologous blood drawn from contralateral upper limb vein + 1 ml 0.5% bupivacaine, and 30 patients received 2 ml local corticosteroid + 1 ml 0.5% bupivacaine at the lateral epicondyle. Outcome was measured using a pain score and Nirschl staging of lateral epicondylitis. Follow-up was continued for total of six months, with assessment at one week, four weeks, 12 weeks and six months. Results. The corticosteroid injection group showed a statistically significant decrease in pain compared with autologous blood injection group in both visual analogue scale (VAS) and Nirschl stage at one week (both p < 0.001) and at four weeks (p = 0.002 and p = 0.018, respectively). At the 12-week and six-month follow-up, autologous blood injection group showed statistically significant decrease in pain compared with corticosteroid injection group (12 weeks: VAS p = 0.013 and Nirschl stage p = 0.018; six months: VAS p = 0.006 and Nirschl p = 0.006). At the six-month final follow-up, a total of 14 patients (47%) in the corticosteroid injection group and 27 patients (90%) in autologous blood injection group were completely relieved of pain. Conclusions. Autologous blood injection is efficient compared with corticosteroid injection, with less side-effects and minimum recurrence rate

We studied the vascular pattern of human posterior tibial tendons by injection techniques and immunohistochemically using antibodies against laminin. The intravascular volume of the posterior tibial tendon was determined using a new method of injection of a solution of . 99m. Tc and gelatin ink into the lower legs of cadavers. Three segments of 1 cm length from different regions of the human posterior tibial tendon were measured using a gamma well counter. The main blood supply arises from the posterior tibial artery. Blood vessels enter the paratenon of the posterior tibial tendon via a mesotenon from the posterior aspect. From the paratenon, the blood vessels penetrate the posterior tibial tendon and anastomose with a longitudinally orientated intratendinous network. The number of vessels in the substance of the tendon is consistently less than that in the surrounding paratenon. The distribution of blood vessels within the posterior tibial tendon is not homogeneous. In the retromalleolar region the intravascular volume was significantly reduced with a mean value of 15 μl/g of tendon tissue. There was no significant difference between the mean intravascular volumes of the proximal and distal areas (distal, 27.7 μl/g tendon tissue; proximal, 30 μl/g tendon tissue). The immunohistochemical investigation showed that there was no immunostaining for laminin in the anterior part of the tendon in the region where it passes behind the medial malleolus. This region is avascular. The most frequent site of rupture of the posterior tibial tendon is in the region behind the medial malleolus. A potential endogenous risk factor may be the limited healing potential of avascular tissue

This prospective randomised clinical trial evaluated the effect of alternatives for allogeneic blood transfusions after total hip replacement and total knee replacement in patients with pre-operative haemoglobin levels between 10.0 g/dl and 13.0 g/dl. A total of 100 patients were randomly allocated to the Eprex (pre-operative injections of epoetin) or Bellovac groups (post-operative retransfusion of shed blood). Allogeneic blood transfusions were administered according to hospital policy. In the Eprex group, 4% of the patients (two patients) received at least one allogeneic blood transfusion. In the Bellovac group, where a mean 216 ml (0 to 700) shed blood was retransfused, 28% (14 patients) required the allogeneic transfusion (p = 0.002). When comparing Eprex with Bellovac in total hip replacement, the percentages were 7% (two of 30 patients) and 30% (nine of 30 patients) (p = 0.047) respectively, whereas in total knee replacement, the percentages were 0% (0 of 20 patients) and 25% (five of 20 patients) respectively (p = 0.042). Pre-operative epoetin injections are more effective but more costly in reducing the need for allogeneic blood transfusions in mildly anaemic patients than post-operative retransfusion of autologous blood

We hypothesised there was no clinical value in using an autologous blood transfusion (ABT) drain in either primary total hip (THR) or total knee replacement (TKR) in terms of limiting allogeneic blood transfusions when a modern restrictive blood management regime was followed. A total of 575 patients (65.2% men), with a mean age of 68.9 years (36 to 94) were randomised in this three-arm study to no drainage (group A), or to wound drainage with an ABT drain for either six hours (group B) or 24 hours (group C). The primary outcome was the number of patients receiving allogeneic blood transfusion. Secondary outcomes were post-operative haemoglobin (Hb) levels, length of hospital stay and adverse events. This study identified only 41 transfused patients, with no significant difference in distribution between the three groups (p = 0.857). The mean pre-operative haemoglobin (Hb) value in the transfused group was 12.8 g/dL (9.8 to 15.5) versus 14.3 g/dL (10.6 to 18.0) in the non-transfused group (p < 0.001, 95% confidence interval: 1.08 to 1.86). Post-operatively, the median of re-transfused shed blood in patients with a THR was 280 mL (Interquartile range (IQR) 150 to 400) and in TKR patients 500 mL (IQR 350 to 650) (p <  0.001). ABT drains had no effect on the proportion of transfused patients in primary THR and TKR. The secondary outcomes were also comparable between groups. Cite this article: Bone Joint J 2014;96-B:765–71

Following total hip arthroplasty (THA) and total knee arthroplasty (TKR) only the ‘visible’ measured blood loss is usually known. This underestimates the ‘true’ total loss, as some loss is ‘hidden’. Correct management of blood loss should take hidden loss into account. We studied 101 THAs and 101 TKAs (with re-infusion of drained blood). Following THA, the mean total loss was 1510 ml and the hidden loss 471 ml (26%). Following TKA, the mean total loss was 1498 ml. The hidden loss was 765 ml (49%). Obesity made no difference with either operation. THA involves a small hidden loss, the total loss being 1.3 times that measured. However, following TKA, there may be substantial hidden blood loss due to bleeding into the tissues and residual blood in the joint. The true total loss can be determined by doubling the measured loss

Aims

During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting.

We determined the effect of the surgical approach on perfusion of the femoral head during hip resurfacing arthroplasty by measuring the concentration of cefuroxime in bone samples from the femoral head. A total of 20 operations were performed through either a transgluteal or an extended posterolateral approach. The concentration of cefuroxime in bone was significantly greater when using the transgluteal approach (mean 15.7 mg/kg; 95% confidence interval 12.3 to 19.1) compared with that using the posterolateral approach (mean 5.6 mg/kg; 95% confidence interval 3.5 to 7.8; p < 0.001). In one patient, who had the operation through a posterolateral approach, cefuroxime was undetectable. Using cefuroxime as an indirect measure of blood flow, the posterolateral approach was found to be associated with a significant reduction in the blood supply to the femoral head during resurfacing arthroplasty compared with the transgluteal approach

1. The results of viscosity measurements on a number of normal, traumatic and osteoarthritic synovial fluids from human knee joints are described and discussed. 2. A decrease of the viscosity of normal synovial fluid with age has been found. 3. The decrease of the viscosity with age and in the pathological groups is analysed and its relation to the viscous anomaly is considered (Fig. 6). 4. The question whether dilution or depolymerisation is the important factor in decrease of viscosity in these groups, and the value of viscosity measurements as a whole, are discussed. 5. Measurements of pH have been made on the same groups of synovial fluids and on the blood of patients in these groups. 6. The mean values for blood and synovial fluid differ significantly, and the pH of the synovial fluid of adolescents is significantly higher than at other ages. 7. There is no significant difference between the traumatic and osteoarthritic groups, but both are significantly less than the normal. 8. In both fluids the peak frequency in all three groups is the same, that for blood being 7·3 to 7·5 and that for synovial fluid being 7·5 to 7·7 (Fig. 7)

We undertook a prospective controlled clinical trial of 109 patients to determine whether postoperative blood salvage in patients undergoing total hip or knee arthroplasty decreased the need for transfusion with banked blood. The average amount of blood collected in our series was 493 ml, most of which was collected in the first four postoperative hours. In patients undergoing bilateral total knee arthroplasty, there was a 54% reduction in banked blood utilisation. None of our patients developed adverse effects from the reinfused material. The cost of collecting and processing wound drainage using the Haemolite cell washer was $175 per patient, regardless of the volume processed, compared to $125 for a unit of banked blood. By reducing the requirement for homologous transfusion, blood salvage diminishes the risks of transmission of HIV and hepatitis viruses. In those cases where the equivalent of two units of blood are reinfused, blood salvage saves money. However, due to the small amounts of blood collected in unilateral hip or knee arthroplasty, we do not recommend its routine application in these cases

Objectives. T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty. Methods. In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry. Results. The percentages of CD4+ T-cell subtypes in PB were not different between groups. The CD4+ T-cells in the SF of MoM hips showed a completely different distribution of phenotypes compared with that found in the PB in the same patients, including significantly decreased CD4+ T-central memory cells (p < 0.05) and increased T-effector memory cells (p < 0.0001) in the SF. Inducible co-stimulator (ICOS) was the only co-stimulatory molecule with different expression on CD4+ CD28+ cells between groups. In PB, ICOS expression was increased in MoM (p < 0.001) and MoP (p < 0.05) cases compared with the controls. In SF, ICOS expression was increased in MoM hips compared with MoP hips (p < 0.05). Conclusions. Increased expression of ICOS on CD4+ T-cells in PB and SF of patients with failed arthroplasties suggests that these cells are activated and involved in generating immune responses. Variations in ICOS expression between MoM and MoP hips may indicate different modes of arthroplasty failure. Cite this article: Professor P. A. Revell. Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties. Bone Joint Res 2016;5:52–60. doi: 10.1302/2046-3758.52.2000574

This is a longitudinal study of the daily urinary output and the concentrations in whole blood of cobalt and chromium in patients with metal-on-metal resurfacings over a period of four years. Twelve-hour urine collections and whole blood specimens were collected before and periodically after a Birmingham hip resurfacing in 26 patients. All ion analyses were carried out using a high-resolution inductively-coupled plasma mass spectrometer. Clinical and radiological assessment, hip function scoring and activity level assessment revealed excellent hip function. There was a significant early increase in urinary metal output, reaching a peak at six months for cobalt and one year for chromium post-operatively. There was thereafter a steady decrease in the median urinary output of cobalt over the following three years, although the differences are not statistically significant. The mean whole blood levels of cobalt and chromium also showed a significant increase between the pre-operative and one-year post-operative periods. The blood levels then decreased to a lower level at four years, compared with the one-year levels. This late reduction was statistically significant for chromium but not for cobalt. The effects of systemic metal ion exposure in patients with metal-on-metal resurfacing arthroplasties continue to be a matter of concern. The levels in this study provide a baseline against which the in vivo wear performance of newer bearings can be compared

We carried out a retrospective case-control study in 80 patients who underwent a revision total hip replacement. Group A (40 patients) received tranexamic acid and intra-operative cell salvage. Group B (40 patients) was a matched control group and did not receive this management. Each group was divided into four subgroups: revision of both components, revision of both components with bone grafting, revision of the acetabular component with or without bone graft, and revision of the femoral component with or without bone graft. In group A the total number of units transfused was 52, compared with 139 in group B, representing a reduction in blood usage of 62.5%. The mean amount of blood transfused from cell salvage in each group was 858 ml (113 to 2100), 477 ml (0 to 2680), 228 ml (75 to 315) and 464 ml (120 to 1125), respectively. There was a significant difference in the amount of blood returned between the groups (p < 0.0001). In group A, 22 patients needed transfusion and in group B, 37 (p < 0.0001). A cost analysis calculation showed a total revenue saving of £70 000 and a potential saving throughout our facility of £318 288 per year. Our results show that a significant reduction in blood transfusion can be made using combined cell salvage and tranexamic acid in revision surgery of the hip

1. Previous investigations into the blood supply of the femoral shaft are reviewed. 2. Details of the blood supply of the shaft of the femur in seventeen children under one year of age, and in ten adults, are given. 3. These findings are discussed with special reference to the fate of the femoral shaft after fracture or operation

We performed a randomised, controlled trial involving 150 patients with a pre-operative level of haemoglobin of 13.0 g/dl or less, to compare the effect of either topical fibrin spray or intravenous tranexamic acid on blood loss after total knee replacement. A total of 50 patients in the topical fibrin spray group had 10 ml of the reconstituted product applied intra-operatively to the operation site. The 50 patients in the tranexamic acid group received 500 mg of tranexamic acid intravenously five minutes before deflation of the tourniquet and a repeat dose three hours later, and a control group of 50 patients received no pharmacological intervention. There was a significant reduction in the total calculated blood loss for those in the topical fibrin spray group (p = 0.016) and tranexamic acid group (p = 0.041) compared with the control group, with mean losses of 1190 ml (708 to 2067), 1225 ml (580 to 2027), and 1415 ml (801 to 2319), respectively. The reduction in blood loss in the topical fibrin spray group was not significantly different from that achieved in the tranexamic acid group (p = 0.72)

1. In rabbit knees the effects of daily injections of saline, Varidase, blood, blood and Varidase simultaneously, and blood alternating with Varidase every third day have been compared. 2. Saline alone produces changes in joint cartilage comparable with a slight damage to the gel structure of the intercellular matrix. 3. The other four experiments resulted in changes in the articular cartilage comparable with the effects of a partial chemical degradation of the polysaccharide of the intercellular matrix. 4. Blood also induced hypertrophy of the synovial tissues. After the end of the injections healing of the cartilage was slower than with saline or with Varidase. 5. When blood and Varidase were given together the immediate effects were additive, but there was a considerable delay in healing

The effect of Charnley cemented total hip replacement on venous blood flow in the legs and its relationship to deep-vein thrombosis were investigated in 413 patients. Blood flow was measured using strain-gauge plethysmography before operation, after surgery, and after discharge from hospital. There was a significant reduction in both venous capacitance and venous outflow, affecting both legs but greater in the operated leg. Venous flow remained significantly below preoperative levels in the operated leg six weeks after surgery. There was a highly significant correlation between the degree of reduction in blood flow and the development of postoperative deep-vein thrombosis. Venous stasis was shown to be a major factor in venous thrombogenesis

1. A high incidence of paraplegia following operations for the correction of severe scoliosis in adults led to an investigation of the normal blood supply of the human spinal cord. 2. This entailed three methods of study: micro-dissection of the vessels of the spinal cord in thirty-five cadavers; radiological measurements of the spinal canal in fifty healthy subjects; and a study of the macerated spinal column in six adult cadavers. 3. The blood supply of the spinal cord is shown to be least rich, and the spinal canal narrowest, from the T.4 to approximately the T.9 vertebral level. This is named the critical vascular zone of the spinal cord, the zone in which interference with the circulation is most likely to result in paraplegia

Aims. We chose unstable extra-capsular hip fractures as our study group because these types of fractures suffer the largest blood loss. We hypothesised that tranexamic acid (TXA) would reduce total blood loss (TBL) in extra-capsular fractures of the hip. . Patients and Methods. A single-centre placebo-controlled double-blinded randomised clinical trial was performed to test the hypothesis on patients undergoing surgery for extra-capsular hip fractures. For reasons outside the control of the investigators, the trial was stopped before reaching the 120 included patients as planned in the protocol. . Results. In all 72 patients (51 women, 21 men; 33 patients in the TXA group, 39 in the placebo group) were included in the final analysis, with a significant mean reduction of 570.8 ml (p = 0.029) in TBL from 2100.4 ml (standard deviation (. sd). = 1152.6) in the placebo group to 1529.6 ml (. sd. = 1012.7) in the TXA group. . The 90-day mortality was 27.2% (n = 9) in the TXA group and 10.2% (n = 4) in the placebo group (p = 0.07). We were not able to ascertain a reliable cause of death in these patients. . Discussion. TXA significantly reduced TBL in extra-capsular hip fractures, but concerns regarding its safety in this patient group must be investigated further before the use of TXA can be recommended. Take home message: We present a randomised clinical trial that is unique in the literature. We evaluate the effect of TXA in very homogenous population - extra-capsular fractures operated with short intramedullary nails. Cite this article: Bone Joint J 2016;98-B:747–53

1. A study has been made of the blood supply of the human patella. There are two main systems, one penetrating the middle third of the anterior surface and the other entering the lower pole of the bone behind the patellar ligament. 2. The relationship between these findings and the complication of avascular necrosis of the upper fragment of the patella after fracture is discussed. Forty-one cases of necrosis after operation have been studied and notes made on the pathological, clinical and radiological evolution of the condition. Whatever the severity of the ischaemic necrosis the prognosis was not substantially affected and good function was observed in all knees six months after injury. 3. The surgical implications of the vascular anatomy are discussed. It is pointed out that surgical intervention may damage the blood vessels entering the anterior surface of the bone and that circumferential repair of patellar fractures may strangle the vessels in their peripatellar course. 4. If removal of one-half of the patella after a transverse fracture is indicated, vascular studies indicate that the upper fragment should be removed

Objectives. We aimed to examine the characteristics of deep venous flow in the leg in a cast and the effects of a wearable neuromuscular stimulator (geko; FirstKind Ltd) and also to explore the participants’ tolerance of the stimulator. Methods. This is an open-label physiological study on ten healthy volunteers. Duplex ultrasonography of the superficial femoral vein measured normal flow and cross-sectional area in the standing and supine positions (with the lower limb initially horizontal and then elevated). Flow measurements were repeated during activation of the geko stimulator placed over the peroneal nerve. The process was repeated after the application of a below-knee cast. Participants evaluated discomfort using a questionnaire (verbal rating score) and a scoring index (visual analogue scale). Results. The geko device was effective in significantly increasing venous blood flow in the lower limb both with a plaster cast (mean difference 11.5 cm/sec. -1. ; p = 0.001 to 0.13) and without a plaster cast (mean difference 7.7 cm/sec. -1. ; p = 0.001 to 0.75). Posture also had a significant effect on peak venous blood flow when the cast was on and the geko inactive (p = 0.003 to 0.69), although these differences were less pronounced than the effect of the geko (mean difference 3.1 cm/sec. -1. (-6.5 to 10)). The geko device was well tolerated, with participants generally reporting only mild discomfort using the device. Conclusion. The geko device increases venous blood flow in the lower limb, offering a potential mechanical thromboprolylaxis for patients in a cast. Cite this article: Bone Joint Res 2013;2:179–85

The quantification of local bone blood flow in man has not previously been possible, despite its importance in the study of normal and pathological bone. We report the use of positron emission tomography, using 15O-labelled water, to measure bone blood flow in patients with closed unilateral fractures of the tibia. We compared fractured and unfractured limbs; alterations in blood flow paralleled those found in animal models. There was increased tibial blood flow at the fracture site as early as 24 hours after fracture, reaching up to 14 times that in the normal limb at two weeks. Blood flow increase was less in displaced than in undisplaced fractures. The muscle to bone ratios of blood flow were similar to those in previous animal work using other techniques. Positron emission tomography will allow study of human bone blood flow in vivo in a wide variety of pathological conditions

1. Hitherto, no study has been reported on the relative quantitative contributions of blood supply by the different arterial systems of long bone. This paper is a report on such a study in the young adult rabbit. 2. The rates and regional distributions of the blood supply of the nutrient as well as other arteries of the femur were studied after ligation of the nutrient artery. The average rates of reduction in blood flow per minute for the first five minutes through the entire femur as well as the shaft, and the epiphysis and metaphysis on each end, were measured and analysed. The bone blood flow was measured by the method of bone clearance of blood strontium 85. 3. The normal average rate of blood flow through the femurs of average weight of 9·38 grammes was 0·90±0·05 millilitres per minute, or 9·60±0·47 millilitres per minute per 100 grammes of bone. 4. The nutrient artery contributed at least 46 per cent of the normal total blood supply of the entire femur and at least 71 per cent of the normal total blood flow of the shaft including its marrow, and 37 per cent and 33 per cent of the normal total blood flow of the upper and the lower epiphysial and metaphysial areas respectively. 5. About 63 per cent, 30 per cent and 67 per cent of the total normal blood flow through the upper epiphysis and metaphysis, the shaft and the lower epiphysis and metaphysis respectively are still intact in the first five minutes after ligation of the nutrient artery, which represent the approximate proportions of the blood supply by the other regional arteries. 6. These quantitative data obtained in this study offer good support to the qualitative observations made by many previous workers

The aim of this study was to define the microcirculation of the normal rotator cuff during arthroscopic surgery and investigate whether it is altered in diseased cuff tissue. Blood flow was measured intra-operatively by laser Doppler flowmetry. We investigated six different zones of each rotator cuff during the arthroscopic examination of 56 consecutive patients undergoing investigation for impingement, cuff tears or instability; there were 336 measurements overall. The mean laser Doppler flowmetry flux was significantly higher at the edges of the tear in torn cuffs (43.1, 95% confidence interval (CI) 37.8 to 48.4) compared with normal cuffs (32.8, 95% CI 27.4 to 38.1; p = 0.0089). It was significantly lower across all anatomical locations in cuffs with impingement (25.4, 95% CI 22.4 to 28.5) compared with normal cuffs (p = 0.0196), and significantly lower in cuffs with impingement compared with torn cuffs (p < 0.0001). Laser Doppler flowmetry analysis of the rotator cuff blood supply indicated a significant difference between the vascularity of the normal and the pathological rotator cuff. We were unable to demonstrate a functional hypoperfusion area or so-called ‘critical zone’ in the normal cuff. The measured flux decreases with advancing impingement, but there is a substantial increase at the edges of rotator cuff tears. This might reflect an attempt at repair