How to avoid systematic postoperative blood test after total hip arthroplasty: A new risk scoring system compared to Wu's score.

BACKGROUND: Routine laboratory studies are often performed following total hip arthroplasty (THA). However, lately, their necessity has been challenged and risk factors for postoperative transfusion are still debated. Recently, a risk scoring system to single out patients that should have a postoperative blood test has been published by Wu et al. The purposes of this retrospective study were: (1) to validate this recently published risk scoring system to identify patients who should have a postoperative laboratory test; (2) to single out risk factors of postoperative transfusion; (3) to determine if another score can more accurately predict the need for postoperative transfusion. HYPOTHESIS: Wu et al.'s risk scoring system can accurately identify patients who should have a postoperative blood test. METHODS: In all, 1693 patients who underwent primary THAs between June 2015 and October 2020 were screened for potential eligibility to include 1000 patient for analysis. Preoperative and postoperative blood tests were done for every patient. Clinical information and laboratory results were retrospectively collected and analyzed. A descriptive analysis followed by univariate and multivariate analysis were sequentially performed. A multiple logistic regression model was employed to determine a formula predicting the transfusion risk called THABUS for Total Hip Arthroplasty Blood test Usefulness Score. The risk scoring system for complete blood count published by Wu et al. in may 2020 was performed for every patient and compared to the THABUS predictive model. RESULTS: The transfusion rate was 2.3% (23/1000). The risk-scoring system published by Wu and al. showed that a laboratory test was necessary for 60.6% (606/1000) however 13% (3/23) of the patients who needed a blood transfusion were missed by the risk-scoring system, giving it a sensitivity of 86.95% and a specificity of 40%. Increasing age, arterial hypertension, female gender, low preoperative hemoglobin, ASA score≥2 and diagnosis of osteonecrosis of the femoral head were significantly associated with postoperative transfusion. The THABUS formula can predict the risk for transfusion with a sensibility of 96.65% and a specificity of 75.54%. In our cohort of 1000 patients, following the THABUS formula would have led to 261 postoperative blood test and cost savings of 32,132$. Only one patient (4.3%) was missed by our new score. The THABUS formula is significantly better than Wu et al.'s complete blood count score in identifying both patient that will need a transfusion (p<0.01) and those who shouldn't have a postoperative blood test (p<0.001). Medical intervention because of creatinine or electrolytes abnormality was needed in 0.3% (3/1000) of patients. DISCUSSION: In this study Wu et al.'s recently published complete blood count risk-scoring system was not validated. However, in the studied population the THABUS formula can accurately target patients who might need a transfusion. The use of the THABUS formula could reduce hospitalization costs without compromising the patients' safety. LEVEL OF EVIDENCE: III, case-control study.

Is simultaneous bilateral total hip arthroplasty deleterious in a biomechanical point of view? A comparative gait analysis study.

PURPOSE: Uni- or bilateral hip osteoarthritis is a common disease generating pain, stiffness, and functional disabilities. Changes in the normal walking with higher energy expenditures are observed. Facing a cruel lack of biomechanical data, we decided to analyse the impact on the walking of single and simultaneous bilateral total hip arthroplasties (THA). METHOD: We conducted a prospective monocentric study, comparing two matched groups of 15 patients able to walk with symptomatic isolated uni- (group 1) or bilateral HO (group 2) and treated respectively by unilateral THA (UTHA) or simultaneous bilateral THA (SBTHA). Surgery was performed by a single surgeon with a direct anterior approach and approved by local ethical committee. Walking was assessed by a « 3D Gait analysis motion¼ pre and at 6 months post operatively. RESULT: In the UTHA group, recovery, i.e., efficiency of locomotor mechanism (p < 0.001) and pelvis sagittal balance (p = 0.031) improved, while external and total work (p = 0.010) decreased post operatively. In the SBTHA group, speed (p = 0.035), step length (p = 0.046), range of motion of knee sagittal stance (p = 0.009) and hip frontal (p = 0.031), and internal work are significatively higher (p < 0.001) post operatively. CONCLUSIONS: This original study attests that THA has a positive impact on walking and energetics outcome in UTHA and SBTHA.

Survey regarding prevention of surgical site infection after orthopaedic surgery in Belgium: are we on the right track?

Prevention strategies are essential to reduce the rate of surgical site infection (SSI) in orthopaedic surgery. Members of the Royal Belgian Society for Orthopaedic Surgery and Traumatology (SORBCOT) and the Belgische Vereniging voor Orthopedie en Traumatologie (BVOT) were asked to answer a 28-question questionnaire on the internet about the application of surgical antimicrobial prophylaxis measures and to compare them with current inter- national recommendations. 228 practicing orthopedic surgeons responded to the survey from different regions (Flanders, Wallonia and Brussels), different hospitals (university, public and private), different levels of experience (< 5 years, 5 to 10 years and > 10 years) and different subspecialties (lower limb, upper limb and spine). Regarding the questionnaire: 7% systematically perform a dental check-up. 47.8% of the participants never carry out a urinalysis, 41.7% when the patient presents symptoms and 10.5% carry it out systematically. 2.6% systematically propose a pre-operative nutritional assessment. 5.3% of respondents suggest stopping biotherapies (Remicade®, Humira®, rituximab®, etc.) before an operation and 43.9% do not feel comfortable with this type of treatment. 47.1% suggest smoking cessation before the operation and 22% of them advise smoking cessation for a period of 4 weeks. 54.8% never carry out MRSA screening. 68.3% systematically per- formed hair removal, 18.5% when the patient had hirsutism. Among them, 17.7% use shaving with razors. Alcoholic Isobetadine is the most used product with 69.3% when disinfecting the surgical site. 42.1% of the surgeons chose a delay between the injection of antibiotic prophylaxis and the incision of less than 30 minutes, 55.7% between 30 and 60 minutes and 2.2% between 60 and 120 minutes. However, 44.7% did not wait for the injection time to be respected before incising. An incise drape is used in 79.8% of cases. The response rate was not influenced by the surgeon's experience. Most international recommendations in terms of prevention of surgical site infection are correctly applied. However, some bad habits are maintained. These include the use of shaving for depilation and the use of non-impregnated adhesive drapes. Practices that could be improved include management of treatment in patients with rheumatic diseases, a 4-week smoking cessation period, and treating positive urine tests only when symptomatic.

Alpha Defensin: A Diagnostic Accuracy Depending on the Infection Definition Used.

BACKGROUND: The purpose of this study was to evaluate the alpha defensin qualitative detection (ADLF) sensitivity and specificity as compared with 3 standard classifications in the diagnostic management of chronic prosthetic joint infections. MATERIALS AND METHODS: A multicenter cohort of 136 patients with a painful arthroplasty was classified into either infected or noninfected according to the Musculoskeletal Infection Society (MSIS) score, Infectious Diseases Society of America (IDSA) score, European Bone and Joint Infection Society (EBJIS) score. The sensitivity and specificity of the ADLF test were calculated for each score. Spearman's correlations between all scores were then analyzed, and multiple logistic regression was applied to identify independent variables strongly connected to the prosthetic joint infection probability. RESULTS: The EBJIS score was positive in 68 patients, IDSA score in 50 patients, MSIS score in 41 patients, and ADLF in 40 patients. The ADLF sensitivity was 87.8% compared with MSIS, 70% compared with IDSA, and 55.8% compared with EBJIS. The ADLF specificity was in the range of 94%-97%. A good correlation was observed between synovial fluid cultures and ADLF (r = 0.73). Low to excellent correlations were recorded between ADLF and the EBJIS (r = 0.58), IDSA (r = 0.68), and MSIS (r = 0.84) scores. The synovial fluid's white blood cell count was proven to be the biological test that most influenced the probability of a positive culture (P value: .005). DISCUSSION: The ADLF sensitivity was variable, whereas its specificity was excellent. The EBJIS score results significantly differed from those obtained via cultures, which possibly explains the ADLF low sensitivity compared with that of the EBJIS score.

Debridement, antibiotics, irrigation and retention in prosthetic joint infection : predictive tools of failure.

Debridement, antibiotic, irrigation and retention of the implant (DAIR) is an attractive treatment for periprosthetic joint infection (PJI). The purpose of this study is to determine predictive factors of failure. We reviewed all DAIR procedures for hip PJI performed between 2002-2017 (n=69). Data recorded included all factors correlated with treatment failure. KLIC score, McPherson adapted score were analyzed. Infection eradication for early PJI (< 4 weeks) was achieved in 68% of patients and was correlated with treatment success (p=0.01). KLIC score (p=0.036), McPherson adapted score (p=0.01), CRP (p=0.025) and late PJI (p=0.031) were significantly predictive of failure treatment. We have established an equation in order to predict failure treatment that has to be validated. DAIR is an effective treatment for early PJI. KLIC score and McPherson adapted score are two ways to predict outcome of a DAIR procedure and should help making the decision in PJI treatment.

Delayed total hip arthroplasty infection with Mycobacterium Tuberculosis complex.

Total Hip Arthroplasty (THA) joint infection is an uncommon (0,3-1,7%) (20) but devastating complication after THA. While mostly caused by Gram-positive bacteria, with staphylococci and streptococci accounting for up to 76% of cases (21), orthopaedic surgeons are sometimes faced with atypical germs such as fungi or mycobacteria. We present a case of THA joint infection caused by Mycobacterium tuberculosis (MT) in a patient without a previous history of MT infection. A literature review was performed, and the treatment is discussed.

Intersegmental kinematics coordination in unilateral peripheral and central origin: Effect on gait mechanism?

BACKGROUND: The gait mechanism requires an efficient intersegmental coordination in order to ensure the displacement of the body while simultaneously maintaining the postural stability. However, intersegmental coordination may be disrupted by neurological or orthopaedic involvement, this increasing the metabolic cost associated with excessive or prolonged muscle co-contraction. RESEARCH QUESTION: Our aim was to evaluate and to understand how hip OA affects lower limbs coordination during gait by using the kinematic segmental covariation law method and predict the energy expenditure. METHODS: In order to evaluate the influence of unilateral alteration of the lower limbs on the gait mechanism, three groups namely 63 hip osteoarthritis patients, 65 chronic hemiparetic stroke patients and 72 healthy subjects performed an instrumented gait analysis. The subjects had to walk barefoot for at least 3 min at a self-selected speed on a force measuring motor-driven treadmill. The biomechanical variables (kinematic, kinetic and energetical cost) were simultaneously recorded. RESULTS: The comparison between the three groups was tested using a repeated measure ANOVA. All biomechanical parameters show significant differences between the 3 groups highlighting the gait alteration for the patients groups. However, the energetic cost remains normal in the hip osteoarthritis group despite of the alteration of the other variables. A multivariate analysis allowed to identify the independent variables affecting more specifically their gait mechanisms. SIGNIFICANCE: This study showed the importance of quantitative functional evaluation in order to better understand the impact of hip osteoarthritis on the gait mechanism. The biomechanical analysis provides objective evidence of the altered gait mechanism and more particularly of the intersegmental coordination in these patients. This gait analysis is therefore an interesting tool in the functional evaluation of the patient to better guide the diagnosis.

The effect of storage delay and storage temperature on orthopaedic surgical samples contaminated by Staphylococcus Epidermidis.

BACKGROUND: Prosthetic Joint Infection (PJI) is a rare but devastating complications with high morbitity and mortality. The identification of the causal microorganism remains crucial and determines therapeutic strategies and success. Microbiology cultures remain the common method to diagnose PJI. Unfortunately, 14% of intra-articular punctures remain negative after culture. The microorganisms are best detected by inoculation of microbiology samples in blood culture bottles (Bactec), or after sonication of the implant and polymerase chain reaction (PCR). The identification of the causal microorganism remains crucial and determines therapeutic success. OBJECTIVES: This study was conducted to assess the effect of culture lead time and sample storage temperature on the detection of the pathogen. METHODS: We obtained bone fragments from femoral heads during primary arthroplasty. Bone fragments were contaminated with a strain of Staphylococcus epidermidis. Four set-ups with different combinations of storage delay and storage temperature were tested. RESULTS: Our study shows the need to cultivate as soon as possible and optimally within 2h after the completion of sampling. Temporary storage in a refrigerator at 4°C also appears to have a positive influence on bacterial viability. At present, these conclusions concern only the Staphylococcus Epidermidis. Others studies are requested to generalize this conclusion to other bacteria.

Uncommon observation of bifocal giant subchondral cysts in the hip: diagnostic role of CT arthrography and MRI, with pathological correlation.

Subchondral cysts (or geodes) are common in osteoarthritis (OA), usually in association with other typical signs, i.e., joint space narrowing, subchondral bone sclerosis, and osteophytosis. However, large lesions without the typical signs of OA or lesions located outside the weight-bearing areas are unusual and may be confused for other conditions, in particular, those of tumoral origin. We report the findings in a 48-year-old man who had been complaining of left buttock pain for 3 years, getting worse over the last year, and an evolutive limited range of motion of the hip. The pain was increased by weight-bearing and was not relieved by nonsteroidal anti-inflammatory drugs. Radiographs and CT showed a large multilocular lytic lesion within the femoral head and a large lytic lesion in the left ilio-ischiatic ramus, raising the question of bifocal tumoral involvement. On MRI, the lesions had low signal intensity on T1- and high signal intensity on T2-weighted MR images, with subtle peripheral enhancement on post-contrast T1-weighted images. CT arthrography, by demonstrating a communication between the femoral head and ischiatic cysts and the joint space allowed us to definitively rule out malignant conditions and to make the diagnosis of subchondral bone cysts. Total hip arthroplasty was performed. Pathological analysis of the resected femoral head and of material obtained at curettage of the ischiatic lesion confirmed the diagnosis of degenerative geodes. This case illustrates an atypical bifocal location of giant subchondral cysts in the hip joint mimicking lytic tumors, in the absence of osteoarthritis or rheumatoid arthritis, and highlights the role of CT arthrography in identifying this condition.

Local complications of massive bone allografts: an appraisal of their prevalence in 128 patients.

Bone allografts were used in our department since twenty-five years to reconstruct segmental bone loss and our data were retrospectively reviewed to assess the complications related to the use of a bone allograft. A consecutive series of 128 patients who received a bone allograft was analyzed. The minimal follow-up was 18 months. Fracture, nonunion, infection and explantation were investigated using a multivariate analysis and logistical regression. Kaplan-Meier survival of the allograft was performed, using allograft removal as the end point. Tumour disease was excluded from this study. Patients were followed up for an average 103 months. Bone tumour occurred in 78% of the patients whereas revision arthroplasty was the cause of implantation in 15% of them. Nonunion was the most prevalent complication, occurring in 35% of the grafts. For nonunion occurrence, the type of reconstruction was found to be a significant variable, the intercalary allograft being the most exposed. Primary bone autografting at the anastomotic site was not significant to prevent nonunion. Fracture of the allograft was the second most frequent complication with a prevalence of 16.4%. The length of the allograft and an osteoarticular allograft were two significant variables in that occurrence. Infection of the allograft was present with a rate of 5.4% of patients. Explantation of failed allografts occurred in 30% of them. The duration of the frozen storage of the allograft and the donor age of the allograft were not significant on any local complication occurrence. Bone allografts are a reliable material but a high rate of local complications must be anticipated.