Introduction:. Most of the published papers on AI based diagnosis have focused on the algorithm's diagnostic performance in a ‘binary’ setting (i.e. disease vs no disease). However, no study evaluated the actual value for the clinicians of an AI based approach in diagnostic. Detection of Traumatic thoracolumbar (TL) fractures is challenging on planar radiographs, resulting in significant rates of missed diagnoses (30-60%), thus constituting a field in which a performance improvement is needed. Aim of this study is therefore to evaluate the value provided by AI generated saliency maps (SM), i.e. the maps that highlight the AI identified region of interests. Methods:. An AI model aimed at identifying TL fractures on plain radiographs was trained and tested on 567 single vertebrae images. Three expert spine surgeons established the Ground Truth (GT) using CT and MRI to confirm the presence of the fracture. From the test set, 12 cases (6 with a GT of fracture and 6 with a GT of no fracture, associated with varying levels of algorithm confidence) were selected and the corresponding SMs were generated and shown to 7 independent evaluators with different grade of experience; the evaluators were requested to: (1) identify the presence or absence of a fracture before and after the saliency map was shown; (2) grade, with a score from 1 (low) to 6 (high) the pertinency (correlation between the map and the human diagnosis), and the utility (the perceived utility in confirming or not the initial diagnosis) of the SM. Furthermore, the usefulness of the SM was evaluated through the rate of correct change in diagnosis after the maps had been shown. Finally, the obtained scores were correlated with the algorithm confidence for the specific case. Results:. Of the selected maps, 8 had an agreement between the AI diagnosis and the GT, while in 4 the diagnosis was discordant (67% accuracy). The pertinency of the map was found higher when the AI diagnosis was the same as the GT and the human diagnosis (respectively p-value = .021 and <.000). A positive and significant correlation between the AI confidence score and the perceived utility (Spearman: 27%, p-value=.0-27) was found. Furthermore, evaluator with experience < 5 year found the maps more useful than the experts (z-score=2.004; p-value=.0455). Among the 84 evaluation we found 12 diagnostic errors in respect to the GT, 6 (50%) of which were reverted after the saliency map evaluation (z statistic = 1.25 and p-value = .21). Discussion:. The perceived utility of AI generated SM correlate with the model confidence in the diagnosis. This highlights the fact that to be considered helpful, the AI must provide not only the diagnosis but also the case specific confidence. Furthermore, the perceived utility was higher among less experienced users, but overall, the SM were useful in improving the human diagnostic accuracy. Therefore, in this setting, the AI enhanced approach provides value in improving the human performance

In the last decades, the use of artificial intelligence (AI) has been increasingly investigated in intervertebral disc degeneration (IDD) and chronic low back pain (LBP) research. To date, several AI-based cutting-edge technologies, such as computer vision, computer-assisted diagnosis, decision support system and natural language processing have been utilized to optimize LBP prevention, diagnosis, and treatment. This talk will provide an outline on contemporary AI applications to IDD and LBP research, with a particular attention towards actual knowledge gaps and promising innovative tools

Abstract. Background. The influence of diagnosis on outcomes after reverse shoulder arthroplasty (RSA) is not completely understood. The purpose of this study was to compare clinical outcomes of different pathologies. Methods. A total of 78 RSAs were performed for the following diagnoses: (1) rotator cuff tear arthropathy(RCA), (2) massive cuff tear(MCT) with osteoarthritis(OA), (3) MCT without OA, (4) arthritis, (5) acute proximal humerus fracture. Mean follow up 36 months (upto 5 years) Range of motion, Oxford Shoulder Score were obtained preoperatively and postoperatively. Results. Mean OSS was 30. The RCA, MCT-with-OA, MCT-without-OA, and arthritis groups all exhibited significant improvements in all outcome scores and in all planes of motion. After adjustment for age and compared with RCA, those with OA had significantly better abduction (P < .05), and those with fractures had significantly worse patient satisfaction (P < .05). Among male patients, those with MCTs without OA had significantly worse satisfaction (P < .05). Conclusion. RSA reliably provides improvement regardless of preoperative diagnosis. Although subtle differences exist between male and female patients, improvements in clinical outcome scores were apparent after RSA

While stable long-term clinical results have been achieved in total joint arthroplasty, periprosthetic joint infection (PJI) has been actualized as difficult issue in this decade. For accurate diagnosis, it is important to establish standard criteria such as MSIS criteria, and it is prevailing now. As an issue involving PJI, however, the existence of viable, but non-culturable (VNC) bacteria must be noticed. It is difficult to identify the VNC state infection, because microbiologic culture result shows negative and other markers tend to be negative. Here, molecular diagnosis based on polymerase chain reaction (PCR) has certain role as potential diagnostic tools for such VNC infection. We have applied a real-time PCR system for the diagnosis of PJI, which is able to detect methicillin-resistant Staphylococcus (MRS) and distinguish gram-positive from gram-negative bacteria. The prominent advantage is that PCR is the singular way to identify MRS in such culture negative cases. Recent development of full-automatic PCR system may improve the time efficiency for routine application. In this presentation, we will show the overall sensitivity and specificity of our PCR system for diagnosing PJI and discuss the current problem and future prospect

Background. The anterior-posterior (AP) pelvis radiograph is crucial for diagnosis of neck of femur (NOF) fractures, especially as this is one of the commonest fractures in the elderly population. Anecdotally we found that initial AP pelvis radiographs for these suspected fractures did not always exhibit the bones sufficiently. Repeat radiographs were needed, leading to delays in diagnosis, treatment, and repeated radiation exposure. Missed diagnoses can have significant consequences for this patient group. We assessed how many initial AP pelvis radiographs taken for suspected NOF fracture fitted criteria for adequate diagnostic imaging. Methods. A retrospective study was carried out assessing the initial AP pelvis radiograph done for each patient presenting to our dedicated NOF unit with suspected NOF fracture for 1st June – 31st July 2014. European Guidelines for Diagnostic Imaging were used as the benchmark. Each radiograph was scored out of six, one for each criteria fulfilled. Guidelines deemed images scoring ≤3 as inadequate. Results. 76 images were assessed with mean patient age 85 years. 51.3% of images scored ≤3 and mean score was 3.59. The least-met criterion was “sharp reproduction of sacrum and vertebral foramina” (26.3%). Crucially only 52.6% achieved “visually sharp reproduction of spongiosa, trochanters and corticalis of both femurs”, important in diagnosis of NOF fractures. Conclusion. More than half initial AP pelvis radiographs taken for suspected NOF fracture were inadequate based on European Guidelines at a dedicated NOF unit. Part of the difficulty can be attributed to challenging patient demographics, however adequate initial radiographs should be aimed for, as repeat radiographs can lead to delays in diagnosis and treatment as well as repeated radiation exposure. Missed diagnoses can have significant consequences for this patient group; we particularly recommend care to be taken to sharply visualise the trochanters and proximal femora to avoid missing subtle fractures

Purpose. Ultrasound of the neonatal and infantile hip is a useful tool in diagnosis and treatment of the developmental dysplasia of the hip (DDH), especially given the fact that numerous cases of DDH do not present any findings in the clinical examination. Methods. Between January 2014 and May 2020, 10536 (5273 neonates and infants, 53% girls, 47% boys) consecutive neonatal and infantile hip joints were studied using the Graf Hip Ultrasound method. Results. 607 hips were diagnosed as abnormal. 523 (5%) hip joints were type IIA, 18 (0.17%) were type ΙΙΒ, 19 (0.18%) were type ΙΙC, 33 (0.31%) were type ΙΙΙ and 14 (0.13%) were type IV. 72% of patients were girls, 55% of patients were firstborns, 35,7% presented breech, 8,2% had a positive family history of DDH, 6% were part of a multiple pregnancy, while 27,2% had no predisposing factor for the disease. Type ΙΙΑ hips were treated with follow- up only and had all matured (turned to normal- type I hips) within a trimester. Type ΙΙΒ και ΙΙC hips were treated using an abductor harness and were normal (type I) within three months. 35.7% of type ΙΙΙ were treated with an abductor harness and 64.3% with hip spica. All type IV hips were treated with hip spica. The duration of therapy for type III and type IV hips was 3 months. Conclusion. The early use of a hip ultrasound provides us with the ability to diagnose and treat DDH efficiently, resulting in a normal hip joint within the first months of life

Objectives. Circulating exosomes represent novel biomarkers for multiple diseases. In this study, we investigated whether circulating exosome levels could be used as a diagnostic biomarker for steroid-induced osteonecrosis of the femoral head (ONFH). Methods. We assessed the serum exosome level of 85 patients with steroid-induced ONFH and 115 healthy donors by Nanosight detection. We then assessed the diagnostic accuracy of serum exosomes by receiver operating characteristic curve analysis. Results. The circulating exosome level of the ONFH group was significantly lower than that of control group. The area under the curve was 0.72, suggesting that the level of serum exosomes has moderate diagnostic accuracy for steroid-induced ONFH. Conclusion. Circulating exosome levels are valuable in the diagnosis of steroid-induced ONFH. Cite this article: H-Y. Zhu, Y-C. Gao, Y. Wang, C-Q. Zhang. Circulating exosome levels in the diagnosis of steroid-induced osteonecrosis of the femoral head. Bone Joint Res 2016;5:276–279. DOI: 10.1302/2046-3758.56.BJR-2015-0014.R1

The medical model of history, examination and investigation forms the bedrock of diagnosis and management of all patients. The essence is the recognition of patterns of symptoms and signs. In the modern era there are an increasing number of non-medical resources ranging from web-based information, computer diagnostic aids and non-specialist healthcare professionals to provide a diagnosis and commence management of a wide range of conditions, including knee problems. We analysed the quality and patterns of clinical presentation in order to answer the question how closely clinical symptoms and examination findings correlate to diagnosis based on MRI scan and/or arthroscopic findings. The analysis was a dataset of a consecutive series of patients, aged 18 to 45, with no past history of knee problems or end stage arthritis, presenting to a single specialist triage physiotherapist, working within an integrated knee service, who fully completed a standardised knee assessment proforma of presenting symptoms and signs at a large district general hospital. The study comprises 86 patients and 98 knees. We analysed this data based on diagnostic findings of MRI scan or arthroscopy to provide definitive intra-articular diagnosis. Based on standard textbook descriptions of common presentations, we went on to define the patients' presentation history and examination as typical or atypical, with typical meaning the symptoms and signs correlated with the diagnosis. The null hypothesis is that patients have a high chance of typical presentations for common knee conditions. In the 75% of patients with a significant intra-articular pathology we found the majority had chondral rather than meniscal tears 1.7 to 1. Forty four percent of patients had atypical symptoms and 71% had atypical clinical signs, 30% and only 26% of the cohort had both typical symptoms and signs together, reflecting a surprisingly low positive predictive probability of symptoms and signs in this group of patients, particularly those with chondral lesions which was 44%. In this cohort, 57% of the cohort has 3 or more multiple diagnoses. In the diagnostically normal group, 43% had symptoms and signs typical for a meniscal tear. We conclude that clinical symptoms and signs surprisingly inaccurate in guiding intra-articular pathology within the knee, even in a sub-set considered the easy and accurate to assess. The number of multiple diagnoses and the incidence of false positive results also means that simplistic interpretations of non-definitive diagnoses and linear causation of pain pathways should be treated cautiously

Introduction and Objective

Medial Knee Osteoarthritis (MKO) is associated with abnormal knee varism, this resulting in altered locomotion and abnormal loading at tibio-femoral condylar contacts. To prevent end-stage MKO, medial compartment decompression is selectively considered and, when required, executed via High Tibial Osteotomy (HTO). This is expected to restore normal knee alignment, load distribution and locomotion. In biomechanics, HTO efficacy may be investigated by a thorough analysis of the ground reaction forces (GRF), whose orientation with respect to patient-specific knee morphology should reflect knee misalignment. Although multi-instrumental assessments are feasible, a customized combination of medical imaging and gait analysis (GA), including GRF data, rarely is considered. The aim of this study was to report an original methodology merging Computed-Tomography (CT) with GA and GFR data in order to depict a realistic patient-specific representation of the knee loading status during motion before and after HTO.

Chronic compartment syndrome (CCS) is usually considered to be due to ischaemia of muscle. We have attempted to use the direct measurement of muscle blood flow for diagnosis since the assessment of intracompartmental pressure does not provide accurate knowledge of the vascular state. We recorded simultaneously continuous measurements of the laser Doppler flow (LDF) in muscle and the intracompartment pressure (ICP) after exercise in seven patients with CCS, and in seven control subjects. The mean ICP was 74.1 ± 4.4 mmHg in CCS patients and 24.2 ± 3.4 mmHg in control subjects one minute after exercise, decreasing to 34.6 ± 2.3 mmHg and 15.0 ± 1.6 mmHg at 20 min, respectively. The LDF was 0.80 ± 0.11 arbitrary units (AU) in control subjects and 1.09 ± 0.14 AU in CCS patients one minute after exercise, and 0.41 ± 0.11 AU and 0.27 ± 0.04 AU, respectively, at the end of the recovery period. The ICP showed a progressive decrease over time in both groups. The LDF decreased sharply during the first minutes of recovery in control subjects, but in patients with CCS there was a delayed hyperaemic peak with blood flow reaching 0.84 ± 0.10 AU at nine minutes as against 0.33 ± 0 .06 AU for control subjects (p < 0.01). The ICP increased in both control subjects and CCS patients after exercise with no clear cut-off point between the groups. By contrast, changes in muscle blood flow over time were clearly different between control subjects and patients with CCS. For this reason, LDF should be investigated further as a technique for the diagnosis of CCS

In this study, we evaluated the labrum tear using radial sequence 3D Multiple Echo Recombined Gradient Echo (MERGE) MRI without arthrography based on modified Czerny's classification, comparing with actual arthroscopic findings. A total of 61 hips including 27 hips of femoroacetabular impingement (FAI), 19 hips of borderline development dysplasia of the hip (BDDH) and 15 hips of early stage osteoarthritis (OA) were enrolled this retrospective study. MRI findings evaluated in each three regions of interest; anterior region, anterolateral region, and lateral region. The cases with severe degeneration that is not concordant with any original Czerny's classification is defined as stage4. We compared MRI findings with arthroscopic findings and calculated the sensitivity, specificity, and likelihood ratio in terms of the existence of labrum tear. MRI findings revealed labrum tear more frequently in anterolateral than lateral (p<0.001). Especially in FAI group, labrum tear was more frequently observed by MRI in anterolateral than lateral (p=0.006). In comparison with MRI findings and arthroscopic findings, the sensitivity was 97%, specificity was 79% and likelihood ratio was 4.59 as average of all regions in terms of the existence of labrum tear. In each region, sensitivity and specificity was 97% and 50% in anterior, 97% and 100% specificity in anterolateral, 94% and 81% in lateral, respectively. Thus, MERGE MRI revealed excellent sensitivity and specificity for diagnosis of labrum tear, especially in anterolateral region. The cases with severely degenerated labrum were classified as newly defined stage 4, which was recognized frequently in OA cases

Metal instrumentation (rods and screws) is used to stabilise the spine after trauma, malignancy or deformity. Approx 3% become infected often necessitating removal of metal. At surgery tissue samples and metal are removed for culture, but many clinical laboratories are not equipped to process metal or use simple culture methods. The causative bacteria exist as biofilms on the metal and they are often anaerobic and slow-growing, so conventional culture methods often fail to detect them. Also, they are common contaminants leading to diagnostic uncertainty. We have established a laboratory protocol to overcome these problems.

Removed metalwork was sonicated and the sonicate centrifuged and the supernatant discarded. Quantitative aerobic and anaerobic culture of the resuspended pellet for 14 days and microscopy were carried out.

Metalwork from 11 suspected infected cases was culture-positive (median 2857, 60–5000cfu/mL). Microscopy revealed an infection due to Candida albicans that would not have been detected otherwise. Bacteria were isolated from 8 of 10 non-infected cases (median 15, 0–35 cfu/mL). Conventionally processed samples failed to grow in 4 infected cases. (cfu/mL infected vs noninfected cases p=0.0093)

Micro-organisms on spinal metalwork grow as biofilms and they require sonication to dislodge them. The causative bacteria are slow-growing and P acnes is anaerobic and requires prolonged incubation. S epidermidis and P acnes are common contaminants and quantitative culture helps to distinguish pathogens from contaminants, removing the diagnostic uncertainty that conventional methods give. Microscopy of the sonicate can reveal micro-organisms that fail to grow on culture. We recommend that sonication of metalwork, prolonged anaerobic incubation and quantitative culture be adopted to improve diagnostic clarity for spinal instrumentation infections.

Magnetic resonance imaging (MRI) is a useful diagnostic tool in evaluating meniscus pathology in the knee. Data from available literature suggests sensitivity and specificity rates around 90% when compared to the gold standard findings at knee arthroscopy. We sought to evaluate the sensitivity, specificity and precision rate (positive predictive value) of MRI at diagnosing meniscus tears within our unit.

A retrospective audit of a total of 79 MRI reports and arthroscopic findings spanning a one year period was carried out. There were 66 positive MRI reports and 13 negative reports. There were 6 false positives 4 false negatives when compared to arthroscopic findings. The sensitivity of MRI for detecting meniscus tears was 93.7% with 60 out of 64 tears detected. All 4 false negatives also had at least grade III osteoarthritic changes at arthroscopy. Specificity was rather low at 60% with MRI reporting 6 tears (false positives) out of 15 patients who had no tears found at arthroscopy. The positive predictive value (precision rate) of MRI detecting tears was 90.9%.

This data shows that MRI in our unit has a comparable high sensitivity to that in various literature making it a useful tool at ruling out disease with a negative result in the clinical setting. A more useful parameter in the clinical setting is its high precision rate when faced with a positive result. However, its specificity is much lower than that in most published data. A total of 6 tears on MRI turned out not to be on arthroscopy meaning patients could have been subjected to an avoidable invasive procedure in the absence of any other indication. This highlights the importance of obtaining reports from experienced musculoskeletal radiologists and the need for surgeons to review MRI images and match them to clinical information prior to subjecting patients to surgery.

We have designed a prospective study to evaluate the usefulness of prolonged incubation of cultures from sonicated orthopaedic implants. During the study period 124 implants from 113 patients were processed (22 osteosynthetic implants, 46 hip prostheses, 54 knee prostheses, and two shoulder prostheses). Of these, 70 patients had clinical infection; 32 had received antibiotics at least seven days before removal of the implant. A total of 54 patients had sonicated samples that produced positive cultures (including four patients without infection). All of them were positive in the first seven days of incubation. No differences were found regarding previous antibiotic treatment when analysing colony counts or days of incubation in the case of a positive result. In our experience, extending incubation of the samples to 14 days does not add more positive results for sonicated orthopaedic implants (hip and knee prosthesis and osteosynthesis implants) compared with a conventional seven-day incubation period.

Cite this article: Bone Joint J 2013;95-B:1001–6.

The precise point of intradural rupture in preganglionic traction injuries to the brachial plexus has been a subject of controversy. In this study of avulsed roots we have shown that rupture occurs at varying levels. True avulsion of the root with attached spinal cord tissue was seen in two cases and in the remainder rupture was peripheral to the central-peripheral transition zone. We have further shown that corpora amylacea marked the boundary between tissue of the central and peripheral nervous systems. This observation provides a basis for renewed work towards the direct repair of intradural ruptures of the ventral and dorsal roots.

Summary

Management of metal on metal hip replacements can be accomplished with a simple algorithm including easily available metal ion levels and hip MRI with metal artifact reducing software. After revision serum metal ion levels can be expected to fall rapidly.

A Morel-Lavallee lesion (MLL) is a benign cystic lesion that occurs due to injury to the soft-tissue envelope's perforating vascular and lymphatic systems, resulting in a distinctive hemolymphatic fluid accumulation between the tissue layers. The MLL has the potential to make a significant impact on the treatment of orthopaedic injuries. A 79-year-old male patient community ambulatory with assisting aid (cane) known case of Diabetes mellitus, hypertension, bronchial asthma and ischemic heart disease. He was brought to the Emergency, complaining of right hip discomfort and burning sensation for the last 5 days with no history of recent trauma at all. Patient had history of right trochanteric femur fracture 3 years ago, treated with DHS in a privet service. Clinical and Radiological assessment showed that the patient mostly has acute MLL due to lag screw cut out. We offered the patient the surgical intervention, but he refused despite explaining the risks of complications if not treated and preferred to receive the conservative treatment. Compression therapy management explained to him including biker's shorts (instructed to be worn full-time a day) and regular follow up in clinic. Symptom's improvement was reported by the patient in the subsequent visits. In the polytrauma patient, a delayed diagnosis of these lesions is conceivable due to the presence of more visible injuries. It's located over the greater trochanter more commonly, but sometimes in other areas such as the lower lumbar region, the thigh, or the calf. Incorrect or delayed diagnosis and care can have unfavorable outcomes such as infection, pseudocyst development, and cosmetologically deformity. Magnetic resonance imaging (MRI) and ultrasound will aid in MLL diagnosis. However, the effectiveness of MLL therapy remains debatable. We strongly believe that the MLL caused due to tangential shear forces applied to the soft tissue leads to accumulation of the blood and/or lymph between the subcutaneous and overlying fascia and it often misdiagnosed due to other distracting injuries. Nontheless, in our case we reported MLL occur due to internal pressure on the fascia caused by cut out of DHS lag screw

Magnetic resonance imaging (MRI) is the gold standard for the diagnosis of the pathologies affecting the glenohumeral joint and the rotator cuff diseases. MRI allows to highlight anatomic discontinuities of both muscles and tendons. However, MRI diagnostic accuracy has not proven to be highly sensitive in distinguishing between a partial-thickness tear and a full-thickness rotator cuff tear. The purpose of this study was to determine if MRI under axial traction can be helpful in increasing MRI sensitivity to identify partial-thickness rotator cuff tears. The study included 10 patients (4 males and 6 females) who had clinical examination and MRI suggesting a partial-thickness rotator cuff tear. They were candidates for shoulder arthroscopy because of persistent symptoms after at least three months of conservative treatment. The patients underwent a new MRI (under axial traction: MRI-AT) with a 4-kg weight applied to the affected arm. Then the patients underwent arthroscopy to confirm the diagnosis. Patients with a suspected full-thickness rotator cuff tear were excluded from the study. Patients’ average age was 52.4 years, and the dominant side was affected in 77.7% of the cases. Preoperative Constant-Murley Score was 57. MRI-AT showed that 3 patients were affected by a complete tear of the rotator cuff, 3 patients by a partial-thickness rotator cuff tear and 4 patients had no lesion. The analysis of data showed that: under axial traction the subacromial space increased by 0,2 mm (P value = 0,001075), the superior glenohumeral space decreased by 2.4 mm (P value = 0,07414), the inferior glenohumeral space increased by 0.3 mm (P value = 0,02942), the acromial angle decreased by 1.9° (P value = 0,0002104) and the acromion-glenohumeral angle decreased by 0.3° (P-value = 0,01974). Two experienced evaluators analyzed previous standard MRI and MRI-AT scans in a double-blinded fashion, with inter-rater evaluation of all the images and measures. Intraclass correlation coefficient (ICC) has been utilized to assess the reliability of the measures performed by different operators. ICC always resulted in more than 0.7, showing a high concordance among values in the same group. A comparative evaluation between standard MRI and MRI-AT has been conducted to highlight possible discrepancies and this has been compared to intraoperative findings. Concordance of the values was 89% between standard MRI and MRI-AT and 100% between MRI under axial traction and intraoperative findings. This study showed a high correlation between the diagnosis achieved with MRI-AT and the intraoperative arthroscopic findings. The use of MRI-AT in clinical practice may improve the diagnostic sensitivity of this method to detect a partial-thickness rotator cuff tear

Primary bone tumors are rare, complex and highly heterogeneous. Its diagnostic and treatment are a challenge for the multidisciplinary team. Developments on tumor biomarkers, immunohistochemistry, histology, molecular, bioinformatics, and genetics are fundamental for an early diagnosis and identification of prognostic factors. The personalized medicine allows an effective patient tailored treatment. The bone biopsy is essential for diagnosis. Treatment may include systemic therapy and local therapy. Frequently, a limb salvage surgery includes wide resection and reconstruction with endoprosthesis, biological or composites. The risk for local recurrence and distant metastases depends on the primary tumor and treatment response. Cancer patients are living longer and bone metastases are increasing. Bone is the third most frequently location for distant lesions. Bone metastases are associated to pain, pathological fractures, functional impairment, and neurological deficits. It impacts survival and patient quality of life. The treatment of metastatic disease is a challenge due to its complexity and heterogeneity, vascularization, reduced size and limited access. It requires a multidisciplinary treatment and depending on different factors it is palliative or curative-like treatment. For multiple bone metastases it is important to relief pain and increases function in order to provide the best quality of life and expect to prolong survival. Advances in nanotechnology, bioinformatics, and genomics, will increase biomarkers for early detection, prognosis, and targeted treatment effectiveness. We are taking the leap forward in precision medicine and personalized care

Septic arthritis following anterior cruciate ligament reconstruction (ACLR) is a rare and serious complication. Previous studies have shown that septic arthritis is associated with inferior outcome of ACLR. Despite that, there is no standardized treatment protocol, and the course of the disease has mainly been studied within single institutions with a small number of patients. The aim of the present study is to describe the course of septic arthritis following ACLR in a large nationwide cohort. The hypothesis was that the clinical presentation of septic arthritis following ACLR varies according to the infectious agent. The present cohort represents patients with septic arthritis identified in a previous study that analyzed compensation claims reported to the Swedish national insurance company (Löf) in 2005–2014 (1). The diagnosis was confirmed by medical experts at Löf after review of medical records. We conducted a comprehensive analysis of the medical records as well as data available from the Swedish National Knee Ligament Registry (SNKLR) for the study group. The study involved 158 patients who received compensation due to developing septic arhtirits. 94 (59.9%) patients were infected with Coagulase negative staphylococci (CoNS), and 25 patients by Staphyolococcus Aureus (S.Aureus) (15.9%). There was a significant difference between the groups regarding Maximum CRP (p<0.001), and duration between ACLR and first washout operation (p<0.005). S.aureus group had the higest maximum CRP (281) and the shortest duration between ACLR and first washout operation (12 days). The Clinical presentation of septic arthritis following ACLR can vary according to the agent causing the infection, and low virulent agents are responsible for the majority of the infections. Clinicians need to be aware of these differences and consider them when making diagnosis or treatment decisions