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. The aim of this study was to determine the impact of the severity of anaemia on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods. A retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database. All patients who underwent primary TKA or THA between January 2012 and December 2017 were identified and stratified based upon hematocrit level. In this analysis, we defined anaemia as packed cell volume (Hct) < 36% for women and < 39% for men, and further stratified anaemia as mild anaemia (Hct 33% to 36% for women, Hct 33% to 39% for men), and moderate to severe (Hct < 33% for both men and women). Univariate and multivariate analyses were used to evaluate the incidence of multiple adverse events within 30 days of arthroplasty. Results. Following adjustment, patients in the THA cohort with moderate to severe anaemia had an increased odds of 6.194 (95% confidence interval (CI) 5.679 to 6.756; p < 0.001) for developing any postoperative complication. Following adjustment, patients in the TKA cohort with moderate to severe anaemia had an increased odds of 5.186 (95% CI 4.811 to 5.590; p < 0.001) for developing any postoperative complication. Among both cohorts, as severity increased, there was an increased risk of postoperative complications. Conclusion. Preoperative anaemia is a risk factor for complications following primary arthroplasty. There is a significant relationship between the severity of anaemia and the odds of postoperative complications. Patients who had moderate to severe anaemia were at increased risk of developing postoperative complications relative to patients with mild anaemia. When considering elective primary THA or TKA in a moderately or severely anaemic patient, surgeons should strongly consider correcting anaemia prior to surgery if possible. Cite this article: Bone Joint J 2020;102-B(4):485–494

Little literature exists about how trauma-induced anemia affects bone healing. Moreover, the definition of anemia has now changed. Until recently, anemia was defined as peripheral Hemoglobin (Hgb) of less than 10 grams/deciliter (gm/dL). Contemporary literature defines anemia as Hgb < 8gm/dL. This re-definition prompted three questions: (1) Does the presence of hemorrhagic anemia (Hgb< 10gm/dL) alter bone healing rates?; (2) If not, does the newer definition (Hgb< 8gm/dL) influence bone healing?; (3) If so, does the newer definition result in more profound changes in bone healing than those previously seen?. We reviewed the charts of patients treated for long bone, diaphyseal fractures over a ten-year period at a Level 1 Trauma Centre to determine rates of fracture healing when anemia by either definition was present. Patients who were skeletally immature, died during hospitalisation, or had incomplete medical records were excluded. All charts were reviewed for: development of anemia, need for blood transfusion, quantity of blood administered and subsequent association with bone healing. Inclusion criteria were met by 627 patients (700 individual fractures). When anemia was defined as Hgb< 10gm/dL, there was an 81.5% healing rate among anemic patients vs 88.8% in non-anemic patients (p=0.013); with a definition of Hgb< 8gm/dL, healing rates were 81.3% and 86.2%, respectively (p=0.041). Tibial healing was especially noted to be influenced (p = 0.002 and 0.0001, respectively). Femoral healing was likewise, but less dramatically, affected (p = 0.0082 and 0.0843). ANOVA showed no significance for open vs closed status, or NSAID use. Our study found a statistically significant difference in long bone healing between patients who developed anemia and those who did not. This is the first evidence based clinical review demonstrating that hemorrhagic anemia has a significant impact on the healing rates of long bone fractures, especially those of the tibia

AIM:. Preoperative anemia in patients undergoing elective total knee arthroplasty has been associated with increased allogeneic blood transfusion therapy and increased rates of in hospital morbidity, which often leads to a longer length of hospital stay. We measured the prevalence of anaemia among patients attending pre-admission clinic before elective major joint arthroplasty. METHODS:. Retrospectively, a randomized sample of all patients undergoing total hip arthroplasty between Dec 2009 and June 2010 were included. The computerized laboratory results were analysed for anaemia as defined by the local reference range (<11.5g/dL for females, <13g/dL for males). Patients were reviewed 6 weeks post operatively and range of flexion and extension was documented. RESULTS:. 96 patients were included with an average age of 67.2 years (SD 9.1). 54% were female; haematology data was complete for all patients. 13 (13.5%, 7 women) of these patients were anaemic on pre-admission haematological testing. There were two intra operative blood transfusions, both were in patients found to be anaemic pre-operatively. Overall, 23% of admissions were transfused an average of 2.2 (SD 0.39) units, an average of 2.2 (SD 1.2) days after surgery. Significantly, 71.4% of those patients identified as anaemic preoperatively were transfused post operatively, whereas only 23.1% of the pre-operatively non-anaemic patients were transfused (p = 0.0026 Fisher's exact test). The average length of stay for patients who were found to be anaemic at pre-operative assessment was 6.8 days (SD 3.5, range 4–13 days) compared to 4.9 days (SD 1.5, range 3–10 days) for the patient group that were not found to be anaemic (p = 0.004). Range of Motion at 6 weeks post operatively also varied significantly. Extension was significantly different (p = 0.003), as was flexion, (p = 0.014) by two-tailed student t-test. DISCUSSION:. A significant number of post-operative transfusions were performed in patients found to be anaemic pre-operatively. We have identified that pre-operative anaemia is associated with two negative outcomes post operatively: Increased length of hospital stay and decreased final range of movement. There is a clear indication for a standardized approach for the detection and treatment of anaemia in preparation for elective total knee arthroplasty

Study Objective: To determine the proportion of patients proceeding to elective total knee arthroplasty with pre-operative anaemia. Background: Over 60,000 primary total knee replacements are performed in England and Wales each year. Blood transfusion can be associated with serious complications. A pre-operative haemoglobin of less than 12 g/dl increases the likelihood of blood transfusion in the peri-operative period by threefold [. 1. ]. Published BOA guidelines recommend patients with pre-operative haemoglobins of 12 g/dl or below in males or 11 g/dl or below in females should have their anaemia investigated and treated prior to total knee arthroplasty. Methods: Patients having elective total knee arthroplasty at our hospital over three-months formed the study population. Data were collected on age, sex, pre- and postoperative haemoglobin, transfusion requirements in the peri-operative period, and whether the patient had inflammatory arthritis. Patients were classified according to the recommended BOA guidelines for deferring elective surgery using pre-operative haemoglobin levels. Post-operative haemoglobin drop was also calculated. Results: Fifteen patients (7%) out of 212 had pre-operative haemoglobins below guideline thresholds. The age range of these patients was 59–84 yr. Nine patients were female. Pre-operative haemoglobin ranged from 9.2–12.0 g/dl. Post-operative haemoglobin drop ranged from 0.5–4.3 g/dl. Six patients received blood transfusion in the peri-operative period (maximum of three units). One patient had a diagnosis of inflammatory arthritis. Discussion: Pre-operative anaemia is common in patients having elective total knee arthroplasty. In this study most anaemic patients did not have anaemias attributable to inflammatory arthritis. Using cell salvage techniques did not prevent peri-operative blood transfusion in anaemic patients. Conclusion: Anaemic patients wanting arthroplasty in favour of surgical deferral and treatment of their anaemia must be made fully aware of the serious complications associated with blood transfusions

Introduction: The correction of anaemia prior to total hip arthroplasty reduces surgical risk, hospital stay and cost. This study considers the benefits of implementing a protocol of identifying and treating pre-operative anaemia whilst the patient is on the waiting list for surgery. Methods: From a prospective series of 301 patients undergoing elective total hip arthroplasty (THA), patients identified as anaemic (Hb< 12 g/dl) when initially placed upon the waiting list were appropriately investigated and treated. Pre- and post- operative haemoglobin (Hb), need for transfusion, and length of hospital stay were collated for the entire patient cohort. Result: 7.6% of patients were anaemic when initially placed upon the waiting list for THA and had a higher transfusion rate (25% to 4%, p< 0.05) and longer hospital stay (7.5 to 6.6 days, p< 0.05). Over 40% of these patients responded to investigation and treatment whilst on the waiting list, showing a significant improvement in Hb level (10.1 to 12.7 g/dl) and improved transfusion rate. Discussion: Quantifying the haemoglobin level of patients when initially placed on the waiting list helps highlight those at risk of requiring a post-operative blood transfusion. Further, the early identification of anaemia allows for the utilization of the waiting list time to investigate and treat these patients. For patients who respond to treatment there is a significant reduction in the need for blood transfusion with its inherent hazards

Introduction: The correction of anaemia prior to total hip arthroplasty reduces surgical risk, hospital stay and cost. This study considers the benefits of implementing a protocol of identifying and treating pre-operative anaemia whilst the patient is on the waiting list for surgery. Methods: From a prospective series of 322 patients undergoing elective total hip arthroplasty (THA), patients identified as anaemic (Hb< 12 g/dl) when initially placed upon the waiting list were appropriately investigated and treated. Pre- and post-operative haemoglobin (Hb), need for transfusion, and length of hospital stay were collated for the entire patient cohort. Result: 8.8% of patients were anaemic when initially placed upon the waiting list for THA and had a higher transfusion rate (23% to 3%, p< 0.05) and longer hospital stay (7.5 to 6.6 days, p< 0.05). Over 40% of these patients responded to investigation and treatment whilst on the waiting list, showing a significant improvement in Hb level (10.1 to 12.7 g /dl) and improved transfusion rate. Discussion: Quantifying the haemoglobin level of patients when initially placed on the waiting list helps highlight those at risk of requiring a post-operative blood transfusion. Further, the early identification of anaemia allows for the utilization of the waiting list time to investigate and treat these patients. For patients who respond to treatment there is a significant reduction in the need for blood transfusion with its inherent hazards

This trial aims to assess the effectiveness of quality improvement collaboratives as a technique to introduce large-scale change and improve outcomes for patients undergoing primary elective total hip or total knee arthroplasty. 41 NHS Trusts that did not have; a preoperative anaemia screening and optimisation pathways, or a methicillin sensitive Staphylococcus Aureus (MSSA) decolonisation pathway, in place were randomised to one of two parallel collaboratives in a two arm, cluster randomised controlled trial. Each collaborative focussed on implementing one of these two preoperative pathways. Collaboratives took place from May 2018 to November 2019. 27 Trusts completed the trial. Outcome data were collected for procedures between November 2018 and November 2019. Co-primary outcomes were perioperative blood transfusion (within 7 days of surgery) and deep surgical site infections (SSI) caused by MSSA (within 90 days) for the anaemia and MSSA arms respectively. Secondary outcomes include deep and superficial SSIs (any organism), length of stay, critical care admissions, and readmissions. Process measures include the proportion of patients receiving each preoperative initiative. 19,254 procedures from 27 Trusts are included. Process measures show both preoperative pathways were implemented to a high degree (75.3% compliance in MSSA arm; 61.2% anaemia arm), indicating that QICs can facilitate change in the NHS. However, there were no improvements in blood transfusions (2.9% v 2.3% adjusted-OR 1.20, 95% CI 0.52–2.75, p=0.67), MSSA deep SSIs (0.13% v 0.14% adjusted-OR 1.01, 95%CI 0.42–2.46, p=0.98), or any secondary outcome. Whilst no significant improvement in patient outcomes were seen, this trial shows quality improvement collaboratives can successfully support the implementation of new preoperative pathways in planned surgery in the NHS

Introduction: Moderate and major operation concerning trauma or selective procedures (like total ¥2) joint replacement) can lead to considerable amount of blood loss and postoperative anaemia. This loss affects negatively the patients’ postoperative course concerning mortality, morbidity as well as patients’ recovery. We decided to provide these patients with Epoetin Alpha in the early postoperative period to control anaemia. Material and Methods: In our Department, from July 2000 until March 2002, we treated 42 patients with postoperative anaemia due to moderate or major operations (like hip and femoral fractures, total joint replacements). Patients’ age ranged from 28 to 85 years, hi this study we included all patients with 9g/dl < Hb < 1 Ig/dl on second postoperative day, without coexisted contraindications for administration of Epoetin Alpha. Patients having been transfused due to serious postoperative anaemia were not included in this study. Laboratory tests included full blood count check up to the end of treatment. Patients were divided in two groups, hi the first group (18 patients) were provided 2 X 10000 units Epoetin Alpha daily for 15 days, hi the second group (after August 2001) we provided 40000 units X 4 every three days, hi all cases we provided Fe per os. One patient (in the second group) sustained diffuse intravascular coagulation (DIG) on the 13th postoperative day and finally she died. In the first group we noticed an increase of Ht by 4 units (mean rate) and in the second group by 6 units. Two cases in the first group presented a slight raise of the Ht (one unit), while the patient who presented DIG belonged to the second group. No patient was transfused postoperatively. Mobilization of patients especially the elderly was earlier than usual. An interesting notice was the raise of platelets (> 600000) in nine cases of the second group and in only two cases of first group, without complications. This raise was attributed to the stimulation of bone marrow due to the fast blood loss during the operation. Conclusion: The effectiveness and safety of Epoetin Alpha has been proved in many studies concerning selective orthopaedic operations. Update results show that Epoetin Alpha has a significant effect in the treatment of postoperative anaemia. Of course further investigations (like double blind studies and control of potential complications from administration) are mandatory

1. The bone changes are described in fifty-one cases of sickle cell anaemia. nineteen cases of sickle cell haemoglobin C disease and two cases of sickle cell thalassaemia. 2. Avascular necrosis of the head of the femur has been found in all three types of sickle cell disease. These responded to treatment. 3. The changes found in six cases of Perthes' disease in the negro are compared with the changes in avascular necrosis of the head of the femur in sickle cell disease. 4. Hyperplastic bone changes are seen only in true sickle cell anaemia and not in the variants. 5. Secondary osteomyelitis appears to be fairly common in sickle cell anaemia. Organisms of the salmonella group have often been found in these cases

Purpose of the study: The major functional impairment which results from femoral head necrosis in patients with sickle-cell anemia leads to implantation of a total hip arthroplasty (THA) in many of these often young patients. Intra- and postoperative complications are frequent. Material and methods: In order to better understand the causes of these complications, and to search for ways of preventing them, we analyzed the cases of 35 sickle-cell anemia patients with 38 THA. Mean patient age was 36.4 years for these 22 women and 13 men. Twenty-eight patients had SS hemoglobin, five AS hemoglobin, and two presented sickle-cell-thalassemia (S-ß-hemoglobin). Mean follow-up was 7.6 years (range 2–29 years). Results: Fifteen patients underwent revision surgery (39%) on average 4.8 years after primary implantation for loosening (n=13) or infection (n=2). Five other prostheses presented peripheral lucent lines (13%). The overall complication rate was 64% (shaft fractures, sickle cell crisis, dislocation or loosening, infection). One patient developed an early superficial infection which resolved. One other patient required revision for severe pain and prosthesis misalignment (flexion-external rotation) but with normal cell counts and a simply inflammatory synovial fluid. The presence of slowly progressive degenerative disease in a patient with severe pain should be carefuly identified before undertaking THA. Systematic samples are necessary. The femor-related complications in this series were: two intraoperative shaft fractures, one fracture below the stem during the first six months, and intraoperative shaft reaming in two. Femoral shaft morphological anomales must be identified preoperatively to enable a proper surgical plan. Small-size femoral stems should be available and zones of sclerosis in the canal must be identified. Cup-related complications are more difficult to analyze. The bony structure of the acetabulum was often remodeled, with very weak cancellous bone. Avivement of the acetabulum must be performed prudently manually or with a well controlled motor. Discussion: Series report few cases in the literature, on average 22 cases (8–36). Mean follow-up was 5.1 years (range 4.6–9.5). The overall rate of complications was 42% (33–59) except for one series with only 2.8%. The rate of deep infection was 14.8% on average (0–36.4). Conclusion: The decision to implant a THA in these young patients must be made conjointly with the patient. Multidisciplinary management before surgery is essential. Precise planning must take into consideration all the potential pitfalls. Special attention must be given to hemodynamic balance, intra- and postoperative oxygenation and the hemoglobin level

We investigated 57 patients with sickle cell anaemia (HbSS) and bone and joint changes. Osteonecrosis simulating a wide range of conditions was a common radiological feature, and osteomyelitis occurred in 61% of cases. Salmonella species were the commonest causative organisms, occurring in 71% of patients with osteomyelitis, although salmonella septic arthritis occurred in only two. The distinction between vaso-occlusive bone crisis and acute osteomyelitis was often difficult since the classical clinical and radiological features and laboratory findings also occurred in bone infarction, a common feature of the disease

Purpose of the study: Infection is a leading cause of morbidity and mortality in sickle cell anemia children. It often triggers an acute episode of anemia with thrombosis. Bone and joint infections are particularly frequent. Diagnosis can be difficult and is sometimes established late. Material and methods: We analyzed retrospectively the cases of 39 children with sickle cell anemia who presented one or more bone and joint infections during a six-year period (January 1998-December 2003). Results: Bone and joint infection involved 14% of all sickle cell children hospitalized during the study period. Mean age was nine years, with no gender predominance. Homozygous subjects were more exposed to infection (73%). The infection revealed the disease in 13% of the children. The rate of bone and joint infection was 62% compared with 38% for osteomyelitis; salmonella were isolated in 38% of cases. Medical treatment with adapted antibiotics and plaster cast immobilization were instituted in all cases and associated with surgical treatment in 25% (arthrotomy for evacuation of purulent collections, cleaning, resection of infected tissue). Outcome was favorable in 77% of cases (cured infection, resumed school activities). Discussion: The frequency of bone and joint infections in sickle cell anemia children in our series was similar to that reported in the literature (10–19%). Compared with children with normal hemoglobin, bone and joint infection in sickle cell anemia children present specific features in terms of localization, blood chemistry findings, causal bacteria, radiographic signs, and therapeutic modalities and sequelae. Conclusion: Sickle cell anemia is a serious hereditary disease. The risk of complications should lead to the development of preventive measures (screening at risk couples, institution of a prenuptial certificate, allogenic bone marrow graft)

Purpose: Patients with sickle-cell anaemia tolerate surgery poorly. They are susceptible to infections and results of orthopaedic treatment are uncertain. Mechanical and infectious complications of total hip arthroplasty encountered in adults have led us to conduct systematic screening and early conservative surgical treatment for osteonecrosis of the femoral head (ONFH). Two surgical techniques have been retained in sickle-cell anaemia patients: simple drilling and femoral osteotomy. Material and methods: Between 1993 and 1999, among 248 sickle-cell anaemia patients examined in our study, 69 had active or quiescent ONFH: stage I=1, stage II=42, stage III=16, stage IV=10. We retained for analysis 16 patients (7 SS and 8 SC, 1 S-betathal), seven men and nine women, age range 15–44 years. These patients had 24 hips with active disease. Simple drilling-biopsy was indicated for osteochondrosis of the hip joint (n=1), stage I ONFH (n=1), stage II ONFH (n=13, early stage III ONFH (n=3) and advanced stage III ONFH (n=3). These three patients with advanced stage III disease underwent drilling for two particular indications: poor general status and disabling pain. Flexion femoral osteotomy was performed for the last three patients with stage III ONFH with localised polar weakening. In all, we performed three femoral osteotomies and 21 simple drilling procedures. Mean postoperative follow-up was six years (2–10). Results: Clinical results were assessed with the Postel-Merle-d’Aubligné score. Among the 24 hips, 20 had a favourable outcome (83%). Discussion: ONFH in sickle-cell anaemia patients requires surgical cure when the femoral heads display recent changes of the bony network (osteolysis, defects) and associated cephalic remodelling with or without pain. After drilling and osteotomy, the disease course shows that the femoral head’s spherical shape is preserved when the lesions are treated early by drilling in stage I, II, and III disease. Bipolar weakening remains an indication for femoral osteotomy. This conservative approach can prevent osteoarthritic degradation. It has enabled us to postpone total hip arthroplasty in young subjects with sickle-cell anaemia

Purpose: The gravity of osteonecrosis in patients with sickle cell anaemia is well known, but the spontaneous course of grade I and II necrosis is not. The first MRI studies performed in these patients were made in 1985. This study compared the spontaneous course in 45 cases of grade I and II necrosis diagnosed between 1985 and 1990 with that in 43 cases of hip necrosis with the same grades I and II diagnosed between 1990 and 1995 in adult patients with sickle cell anaemia treated by medullary drilling with autologous bone marrow grafts. Material and methods: The 45 cases of necrosis followed were diagnosed between 1985 and 1990. These patients did not undergo conservative treatment until the sphericity of the femoral head was lost. They were followed clinically and radiographically up through 2000. The second group of 43 cases of hip necrosis were diagnosed between 1990 and 1995. These patients were treated by meduallary drilling with an autologous bone marrow graft. The bone marrow as harvested from the iliac crests, concentrated and reinjected in the osteonecrotic area. The patients were followed clinically and radiographically until 2000. All patients had an x-ray of the hip (AP and lateral views) at last follow-up. As the follow-up was different for the two groups, comparisons were made using the survival curves; all patients were followed for at least five years. Results: In group I where the clinical course was spontaneous, the spherical shape of the head was lost in 100% of the patients at five years (30% at one year, 60% at two years and 100% at five years), leading to surgery for 80%, usually with prosthesis implantation. In group II where the patients were treated by drilling and autologous bone marrow transplantation, two patients (5%) lost femoral head sphericity at five years. Ten percent of the patients (4 patients) had lost the femoral head sphericity at the current mean follow-up of eight years (minimum five, maximum ten) and required reoperation for prosthesis implantation. MRI and CT imaging in the non-reoperated patients demonstrated a spherical head and remodelling or disappearance of the osteonecrosis at five years. Discussion and conclusion: The spontaneous course of necrosis in adults with sickle cell anaemia is unfavourable after five years. This spontaneous course can be modified (at least the rate of progression) by drilling associated with autologous bone marrow transplantation, if it is performed early enough

A 14 year-old-female, underwent a T3-L3 instrumented posterior spinal fusion for a double major curve. Surgery under controlled hypotensive anesthesia was uneventful, with normal somatosensory and motor potentials. After instrumentation, patient underwent a normal wake-up test. The preoperative haemoglobin and haematocrit was 15.1g/dl with 41%, respectively. Estimated blood loss was 400cc and postoperative haemoglobin and haematocrit were 9.7g/dl and 31% respectively. Clinical examination was normal immediately postoperatively, on the first postoperative day and the beginning of the second postoperative day. At the end of POD 2, the patient started to feel both lower extremities “heavy” and sensitive to touch. She developed generalized proximal lower extremity weakness and was unable to stand. She was also unable to void after catheter removal. At this stage, her hemoglobin had dropped from 10 g/dl on POD 1 to 7.3 g/dl. Her haemoglobin fell to 6.2 g/dl the next day with a haematocrit of 18%. No significant bleeding was noticed, and other than lightheadedness, no haemodynamic changes were noted. Transfusion was performed correcting the haemoglobin to 9.3 g/dl and haematocrit to 27%. Compressive etiology was ruled out by post-operative myelogram-CT. Patient was discharged on POD 13 and was neurologically intact at three month follow-up. Discussion: Delayed neurological deficits have been reported, and are associated most frequently with epidural haematomas. Postoperative hypotension as the etiological factor has been reported only in an adult patient. As cord compression was ruled-out the only event we can correlate with the beginning of the neurological deficit is the unexplained acute drop in haemoglobin levels on the second day, possibly impairing normal cord oxygenation. If this is not the case, we would have to accept false negative results for the three standard methods currently available for spinal cord monitoring during surgery. In this case, the normal postoperative neurological exams, performed during the first 48 hours after surgery, and the subjective symptoms the patient experienced associated with the beginning of motor deficit, leads us to conclude that the injury happened on the second day in relation to the postoperative anaemia. Although we believe children tolerate low levels of haemoglobin, transfusion policies might have to be reconsidered as the cord may be transiently at risk for ischemic events after deformity correction

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

Aims. We aim to evaluate the usefulness of postoperative blood tests by investigating the incidence of abnormal results following total joint replacement (TJR), as well as identifying preoperative risk factors for abnormal blood test results postoperatively, especially pertaining to anaemia and acute kidney injury (AKI). Methods. This is a retrospective cohort study of patients who had elective TJR between January and December 2019 at a tertiary centre. Data gathered included age at time of surgery, sex, BMI, American Society of Anesthesiologists (ASA) grade, preoperative and postoperative laboratory test results, haemoglobin (Hgb), white blood count (WBC), haematocrit (Hct), platelets (Plts), sodium (Na. +. ), potassium (K. +. ), creatinine (Cr), estimated glomerular filtration rate (eGFR), and Ferritin (ug/l). Abnormal blood tests, AKI, electrolyte imbalance, anaemia, transfusion, reoperation, and readmission within one year were reported. Results. The study included 2,721 patients with a mean age of 69 years, of whom 1,266 (46.6%) were male. Abnormal postoperative bloods were identified in 444 (16.3%) patients. We identified age (≥ 65 years), female sex, and ASA grade ≥ III as risk factors for developing abnormal postoperative blood tests. Preoperative haemoglobin (≤ 127 g/dl) and packed cell volume (≤ 0.395 l/l) were noted to be significant risk factors for postoperative anaemia, and potassium (≤ 3.7 mmol/l) was noted to be a significant risk factor for AKI. Conclusion. The costs outweigh the benefits of ordering routine postoperative blood tests in TJR patients. Clinicians should risk-stratify their patients and have a lower threshold for ordering blood tests in patients with abnormal preoperative haemoglobin (≤ 127 g/l), blood loss > 300 ml, chronic kidney disease, ASA grade ≥ III, and clinical concern. Cite this article: Bone Jt Open 2023;4(11):899–905