Background. Septic knee arthritis is one of the most serious complications after total knee arthroplasty (TKA), and the effectiveness of its treatment affects the patient's quality of life. In our super-aging society, the frequency of TKA in the elderly, often combined with various comorbidities, is increasing. Careful management should be considerd during the management of septic arthritis after TKA in these patients. Purpose. To analyze the clinical features and outcomes of septic arthritis after TKA in our institution. Materials and Methods. Between April 1999 and March 2014, 534 TKAs (osteoarthritis [OA]; 381, rheumatoid arthritis [RA]; 154) were performed. Of these patients, 8 with post-operative infected TKA were retrospectively surveyed. Results. The TKA-associated infection rates were 0.83% (0.35%, OA; 1.7%, RA) during the study period. Five male and 3 female patients were included, with a mean age of 68 years (range, 39–88 years) and primary diagnoses of OA (5) and RA (3). Malignant rheumatoid arthritis (MRA) was present in 1 patient. The infection was affected by a comorbidity in 2 (diabetes mellitus and mixed connective tissue disease). Microorganisms were detectable in 7 patients (methicillin-resistant Staphylococcus aureus [MRSA], 1; methicillin-sensitive Staphylococcus aureus, 2; Streptococcus pyogens, 1; Streptococcus oralis, 1; Escherichia coli, 1; Staphylococcus epidermidis, 1; and unknown, 1) (Fig. 1). The use of the Segawa/Leone classification resulted in 5 patients with type III (acute hematogenous) and 3 with type IV (late) infections. Four patients with type III (80%) infection underwent open debridement, continuous irrigation, and successful implant retention (Fig. 2). The MRA patient had type III infection and an MRSA infection that was treated with two-stage revision, but the infection recurred. We could not perform a re-implantation, and resection arthroplasty was needed. Arthroscopic irrigation in 1 patient with type III infection ended in failure, and open debridement was required. We attempted to retain the implant in 1 patient with type IV infection, but implant removal was required. Three patients with type IV infection underwent two-stage revision successfully. Discussion. The post-TKA infection rate was 0.83% in our institution. Of the implants, 50% (type III, 80%; type IV, 0%) were successfully retained. Early open debridement and irrigation are important for implant retention in patients with infected TKAs, while arthroscopic debridement does not appear to be effective for infected TKA. Implant retention was difficult in the presence of resistant microorganisms. Two-stage revision was required in patients with type IV infection, with a success rate of 75%

Squamous Cell Carcinoma (SCC) is a rare complication of chronic osteomyelitis (OM), arising in a sinus tract (Marjolin's Ulcer). We routinely send samples for histological analysis for all longstanding sinus tracts in patients with chronic osteomyelitis. We reviewed the clinical features and outcomes of patients with SCC arising from chronic osteomyellitis. A retrospective study was performed of patients with osteomyelitis between January 2004 and December 2014 in a single tertiary referral centre. Clinical notes, microbiology and histo-pathological records were reviewed for patients who had squamous cell carcinoma associated with OM. We treated 9 patients with chronic osteomyelitis related squamous cell carcinoma. The mean age at time of diagnosis was 51 years (range 41–81 years) with 4 females and 5 males. The mean duration of osteomyelitis was 16.5 years (3–30 years) before diagnosis of SCC. SCC arose in osteomyelitis of the ischium in 5 patients, sacrum in 1 patient, femur in 1 patient and tibia in 2 patients. Osteomyelitis was due to pressure ulceration in 7 patients and post-traumatic infection in 2 patients. The histology showed well differentiated SCC in 4 cases and moderately differentiated SCC in 2 cases with invasion. Two patients had SCC with involvement of bone. One patient had metastatic SCC to bowel. All patients had polymicrobial or Gram-negative cultures from microbiology samples. Four patients (57%) in our series died as result of their cancer despite wide resection. The mean survival after diagnosis of SCC was 1.3 years and mean age at time of death was 44.7 years. Two of these patients had ischial disease and were treated with hip disarticulation, hemi-pelvectomy and iliac node clearance. Five patients remain disease free at a mean of 3.4 years (range 0.1 – 7yrs) after excision surgery. One patient in this group underwent a through-hip amputation, one underwent an above knee amputation and one underwent excision of ischium and surrounding sinuses. Of note, all these patients had clear staging scans at time of diagnosis. This case series demonstrates the consequences of an uncommon complication of osteomyelitis. In our series only 3 patients underwent biopsy for suspected SCC due to clinical appearances. The other cases were all identified incidentally after routine histological sampling, demonstrating the importance of this practice

Aim. To describe the epidemiology, clinical features and outcomes of native joint septic arthritis in adults admitted to Middlemore Hospital in Auckland, New Zealand. Method. Single-centre retrospective cohort study from 2009 to 2014. Patients ≥16 years of age were identified using ICD-10AM coding data. Electronic records were reviewed for demographic, clinical, laboratory, treatment and outcome data. Total and hemi-arthroplasty infections were excluded. Results. 543 episodes in 521 patients were included, with 90% fulfilling Modified Newman's criteria. Septic arthritis incidence was 26/100,000 patient years and was unchanged over the study period. Incidence correlated strongly with age (R. 2. =0.79) and socioeconomic deprivation (R. 2. =0.76). Median age was 49 years, and gender 70% male. Ethnicity was Pacific Island in 36% (22.8% of catchment population). The most commonly involved joints were hand interphalangeal (19%), knee (19%), metacarpophalangeal (17%) and glenohumeral (11%). Arthritis was monoarticular in 93%. Underlying conditions included current smoking (42%), osteoarthritis (29%), diabetes (22%) and gout (15%). Rheumatoid and seronegative arthritis were uncommon (each 2%). Skin/soft tissue infection occurred within 3 months prior in 38%. Osteomyelitis occurred in 26%. Sources of infection included haematogenous (42%), traumatic (34%), and iatrogenic (17%). Causative organism(s) were isolated in 80% of episodes, most commonly Staphylococcus aureus (53%, 13% of which were MRSA) then Streptococcus pyogenes (15%). 28% of culture-positive episodes were polymicrobial. Median antibiotic duration was 4 weeks, with 38% having definitive therapy orally. A median of 1 surgical procedure was undertaken during treatment. Mortality at 30 days was 3%, at 90 days 5% and treatment failure (defined as any of: death <90 days; relapse; reinfection; or ongoing joint infection leading to readmission, amputation, arthrodesis or excision arthroplasty) occurred in 17%. Treatment failure was significantly more common in cases involving large joints (23%, (69/302) vs. 11%, (26/241), p=0.0002) and in haematogenous episodes versus traumatic episodes (21% (47/229) vs. 10% (19/168), p=0.0045). Conclusions. This is the largest series of adult native joint septic arthritis currently available. The extremely high observed septic arthritis incidence (26/100,000 person years) may relate to high rates of skin and soft tissue infection in Auckland, particularly among Pacific people. Small joint infection, often excluded from previous studies, is associated with significantly better outcomes than large-joint infection. Mortality is lower in this cohort than previously reported, possibly due to the inclusion of small joint infections and exclusion of prosthetic joint infections. Acknowledgements. No additional funding was received for this work

Proximal femoral focal deficiency is a congenital disorder of malformation of the proximal femur and/or the acetabulum. Patients present with limb length discrepancy and clinical features along a spectrum of severity. As these patients progress through to skeletal maturity and on to adulthood, altered biomechanical demands lead to progression of arthropathy in any joint within the lower limb. Abnormal anatomy presents a challenge to surgeons and conventional approaches and implants may not necessarily be applicable. We present a case of a 62-year-old lady with unilateral proximal femoral focal deficiency (suspected Aitken Class A) who ambulated with an equinus prosthesis for her entire life. She presented with ipsilateral knee pain and instability due to knee arthritis but could not tolerate a total knee arthroplasty due to poor quadriceps control. A custom osteointegration prosthesis was inserted with a view to converting to the proximal segment to a total hip replacement if required. The patient went on to develop ipsilateral symptomatic hip arthritis but altered acetabular anatomy required a custom tri-flange component (Ossis, Christchurch, New Zealand) and a custom proximal femoral component to link with the existing osseointegration component (Osseointegration Group of Australia, Sydney, Australia) were designed and implanted. The 18 month follow up of the custom hip components showed that the patient had Oxford hip scores that were markedly improved from pre-operatively. Knee joint heights were successfully restored to equal when the patient's prosthesis was attached. The patient describes feeling like “a normal person”, walks unaided for short distances and can ambulate longer distances with crutches. Advances in design and manufacture of implants have empowered surgeons to offer life improving treatments to patients with challenging anatomy. Using a custom acetabular tri-flange and osseointegration components is one possible solution to address symptomatic ipsilateral hip and knee arthropathy in the context of PFFD in adulthood

Aim. Accurate diagnosis is key in correctly managing prosthetic joint infection(PJI). Shoulder PJI definition and diagnosis is challenging. Current PJI definitions, based overwhelmingly in hip/knee research, may not accurately diagnose shoulder PJI. Our aim is to compare the preoperative performance of two PJI definitions comparing it to definitive postoperative classification. Method. This is a retrospective study of patients who have undergone total shoulder revision surgery for infection between 2005 and 2022. Cases were classified using two different PJI definitions: a)the European Bone and Joint Infection Society (EBJIS) and; 2)the 2018 International Consensus Meeting(ICM) PJI specific shoulder definition. Preoperative classification was based on clinical features, inflammatory markers and synovial fluid leukocyte count and definitive classification also considered microbiology and histology results. Results. Preoperative and definitive PJI classification status of the 21 patients included were evaluated and is summarized in table 1. The shoulder specific 2018 ICM definition showed the highest agreement between preoperative and definitive classification (76.2%, k=0.153, p=0.006) compared to EBJIS (52.4%, k=0.205, p=0.006). In all cases, the classification was changed because of positive intraoperative microbiology (at least two identical isolates). Microbiology findings showed coagulase negative staphylococci, Staphyloccocus aureus and Cutibacterium acnes to be the most frequent. Four patients had polymicrobial infections. Conclusions. Both the EBJIS 2021 and 2018 ICM definitions have low accuracy in predicting shoulder PJI preoperatively. Clearly further studies with larger cohorts are in dire need focusing specifically on shoulder revision arthroplasty to improve on existing definitions. Caution is advised while extrapolating of criteria/thresholds recommended for hip/knee joints. For any tables or figures, please contact the authors directly

Aim. Magnetic resonance imaging (MRI) and 2-[. 18. F]-fluoro-2-deoxy-D-glucose (. 18. F-FDG) Positron Emission Tomography, paired with Computed Tomography (PET/CT) are two indicated advanced imaging modalities in the complicated diagnostic work-up of osteomyelitis. PET/MRI is a relatively novel hybrid modality with suggested applications in musculoskeletal infection imaging. The goal of this study was to assess the value of hybrid . 18. F-FDG PET/MRI for chronic osteomyelitis diagnosis and surgical planning. Method. Five suspected chronic osteomyelitis patients underwent a prospective . 18. F-FDG single-injection/dual-imaging protocol with hybrid PET/CT and hybrid PET/MR. Diagnosis and relevant clinical features for the surgeon planning treatment were compared. Subsequently, 36 patients with . 18. F-FDG PET/MRI scans for suspected osteomyelitis were analysed retrospectively. Sensitivity, specificity, and accuracy were determined with the clinical assessment as the ground truth. Standardized uptake values (SUV) were measured and analysed by means of receiver operating characteristics (ROC). Results. The consensus diagnosis was identical for PET/CT and PET/MRI in the prospective cases, with PET/CT missing one clinical feature. The retrospective analysis yielded a sensitivity, specificity, and accuracy of 78%, 100%, and 86% respectively. Area under the ROC curve was .736, .755, and.769 for the SUVmax, target to background ratio, and SUVmax_ratio respectively. These results are in the same range and not statistically different compared to diagnostic value for . 18. F-FDG PET/CT imaging of osteomyelitis in literature. Conclusions. Based on our qualitative comparison, reduced radiation dose, and the diagnostic value that was found, the authors propose . 18. F-FDG PET/MRI as an alternative to . 18. F-FDG PET/CT in osteomyelitis diagnosis, if available

Aim. Accurate diagnosis is key in correctly managing prosthetic joint infection (PJI). Our aim is to compare the preoperative performance of three PJI definitions comparing it to definitive postoperative classification. Method. This is a multicenter retrospective study of patients who have undergone total hip or knee revision surgery in four different European institutions. For this specific study, cases with no preoperative synovial fluid differential leukocyte count and less than four intraoperative microbiology samples were excluded. Cases were classified using the 2021 EBJIS, the 2018 International Consensus Meeting (ICM) and the 2013 Musculoskeletal Infection Society (MSIS) PJI definitions. Preoperative classification was based on clinical features, inflammatory markers and synovial fluid leukocyte count and microbiology results. Results. Preoperative and definitive PJI classification status of the 384 patients included are presented in figure 1. EBJIS definition showed the highest agreement between preoperative and definitive classification (k=0.86, CI95% 0.81–0.90, p<0.001) compared to ICM 2018 (k=0.80, CI95% 0.75–0.84, p<0.001) or MSIS 2013 (k=0.70, CI95% 0.62–0.77, p<0.001). Compared to its respective definitive classification: EBJIS preoperative unlikely result shows 86.8% (95%CI 81.3%–91.2%) sensitivity and 87.7% (95%CI 83.3%–91.1%) negative predictive value (NPV); ICM 2018 preoperative not infected result shows 83.5% (95%CI 77.4%–88.5%) sensitivity and 86.2% (95%CI 81.9%–88.6%) NPV and; MSIS 2013 preoperative not infected result shows 63.9% (95%CI 55.0%–72.1%) sensitivity and 84.3% (95%CI 81.1%–87.1%) NPV. Around half of the preoperative EBJIS likely (45.8%) and ICM 2018 inconclusive (54.5%) turn out to be infected postoperatively. If we consider the more sensitive definition (EBJIS) as the gold standard: ICM 2018 preoperative not infected result shows 75.1% (95%CI 68.5%–81.0%) sensitivity and 78.3% (95%CI 73.9%–82.2%) NPV and; MSIS 2013 preoperative not infected result shows 42.1% (95% CI 35.2%–49.4%) sensitivity and 62.0% (59.2%–64.8) NPV. Conclusions. The EBJIS 2021 definition is not only the most sensitive definition as it was shown to be the most effective in preoperatively ruling out PJI when there is a negative result. For any tables or figures, please contact the authors directly

Lymph node metastasis are a rare occurrence in soft tissue sarcomas of the extremity, arising in less than 5% of patients. Few studies have evaluated the prognosis and survival of patients with a lymph node metastasis. Early reports compared lymph node involvement to lung metastasis, while others suggested a slightly better outcome. The purpose of this study was to evaluate the impact of lymph node metastasis on patient survival and to investigate the histologic and clinical features associated with lymph node involvement. A retrospective review was done of the prospectively collected soft tissue sarcoma database at our institution. Two thousand forty-five patients had surgery for soft tissue sarcoma of an extremity between January 1986 and August 2017. Included patients either presented with a synchronous lymph node metastasis or were diagnosed with a lymph node metastasis after their initial treatment. Demographic, treatment, and outcome data for patients with lymph node involvement were obtained from the clinical and radiographic records. Lymph node metastases were identified as palpable adenopathy by physical examination and were further characterized on cross-sectional imaging by computed tomography (CT) or magnetic resonance imaging (MRI) scans. All cases were confirmed by pathologic examination of biopsy specimens. A pathologist with expertise in sarcoma determined the histologic type and graded tumors as 1, 2, or 3. One hundred eighteen patients with a mean age of 55.7 (SD=18.9) were included in our study. Seventy-two (61.3%) out of 119 patients were male. Thirty six patients (57.1%) had lymph node involvement at diagnosis. The mean follow-up from the date of the first surgery was 56.3 months. The most common histological diagnoses were Malignant fibrous histiocytoma (35) and liposarcoma (12). Ninety eight patients (89%) underwent surgical treatment of the lymph node metastasis while 21 (17.6%) were treated with chemotherapy and/or radiation therapy. The mean survival was 52.6 months (range 1–307). Our results suggest that patients with a lymph node metastasis have a better prognosis than previously described. Their overall survival is superior to patients diagnosed with lung metastasis. A signifant proportion of patients may expect long term survival after surgical excision of lymph node metastasis. Furthermore, our study also indicates that different histological subtypes such as liposarcoma or malignant peripheral nerve sheath tumor (MPNST) may also be responsible for lymph node metastasis. Additional studies to further improve the treatment of soft tissue sarcoma nodal metastasis are warranted

INTRODUCTION. Mechanical loosening of total hip replacement (THR) is primarily diagnosed using radiographs, which are diagnostically challenging and require review by experienced radiologists and orthopaedic surgeons. Automated tools that assist less-experienced clinicians and mitigate human error can reduce the risk of missed or delayed diagnosis. Thus the purposes of this study were to: 1) develop an automated tool to detect mechanical loosening of THR by training a deep convolutional neural network (CNN) using THR x-rays, and 2) visualize the CNN training process to interpret how it functions. METHODS. A retrospective study was conducted using previously collected imaging data at a single institution with IRB approval. Twenty-three patients with cementless primary THR who underwent revision surgery due to mechanical loosening (either with a loose stem and/or a loose acetabular component) had their hip x-rays evaluated immediately prior to their revision surgery (32 “loose” x-rays). A comparison group was comprised of 23 patients who underwent primary cementless THR surgery with x-rays immediately after their primary surgery (31 “not loose” x-rays). Fig. 1 shows examples of “not loose” and “loose” THR x-ray. DenseNet201-CNN was utilized by swapping the top layer with a binary classifier using 90:10 split-validation [1]. Pre-trained CNN on ImageNet [2] and not pre-trained CNN (initial zero weights) were implemented to compare the results. Saliency maps were implemented to indicate the importance of each pixel of a given x-ray on the CNN's performance [3]. RESULTS. Fig. 2 shows the saliency maps for an example x-ray and the corresponding accuracy of the CNN on the entire validation dataset at different stages of the training for both pre-trained (Fig. 2a) and not pre-trained (Fig. 2b) CNNs. Colored regions in the saliency maps, where red denotes higher relative influence than blue, indicate the most influential regions on the CNN's performance. Pre-trained CNN achieved higher accuracy (87%) on the validation set x-rays than not pre-trained CNN (62%) after 10 epochs. The pre-trained CNN's saliency map at 10 epochs identified significant influence of bone-implant interaction regions on the CNN's performance. This indicates that the CNN is ‘looking’ at the clinically relevant features in the x-rays. The saliency maps also demonstrated that the pre-trained CNN quickly learned where to ‘look’, while the not pre-trained CNN struggles. DISCUSSION. An automated tool to detect mechanical loosening of THR was developed that can potentially assist clinicians with accurate diagnosis. By visualizing the influential regions of the x-ray on the CNN performance, this study shed light into CNN learning process and demonstrated that CNN is ‘looking’ at the clinically relevant features to classify the x-rays. This visualization is crucial to build trust in the automated system by interpreting how it functions to increase the confidence in the application of artificial intelligence to the field of orthopaedics. This study also demonstrated that pre-training CNN can accelerate the learning process and achieve high accuracy even on a small dataset. For any figures or tables, please contact the authors directly

Aim. Gram negative bacteria (GNB) are emerging pathogens in chronic post-traumatic osteomyelitis. However, data on multi-drug (MDR) and extensively drug resistant (XDR) GNB are sparse. Methods. A multi-centre epidemiological study was performed in 10 countries by members of the ESGIAI (ESCMID Study Group on Implant Associated Infections). Osteosynthesis-associated osteomyelitis (OAO) of the lower extremities and MDR/XDR GNB were defined according to international guidelines. Data from 2000 to 2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy were retrospectively analyzed. Cure was assessed after the end of treatment as the absence of any sign relevant to OAO. Factors associated with cure were evaluated by regression analysis. Results. A total of 53 infections of OAO of the lower extremities (hip, femur, tibia) were evaluated. Patients were female (n=32, 60.4%), with a mean age (SD) 57(3) years, history of trauma (83%), comorbidities (26.4%). The most frequent GNB were: E.coli (n=15), P.aeruginosa (n=14), Klebsiella spp (n=8), Enterobacter spp (n=8) and Acinetobacter spp (n=5). P.aeruginosa predominated the XDR group than the MDR one (n=6/10 vs n=8/43, p=0.01). Antibiotics were given mostly in combinations (64%) for a median duration of 117 days (SD:31.5). Carbapenems were the most frequently used agents (54.7%), followed by colistin (18.8%) and fluoroquinolones (15%). Surgical treatment included debridement with implant retention (n=22), implant explantation (n=22), new osteosynthesis (n=3), others(n=6). Only failure of the surgical treatment for OAO was associated with lack of cure [OR 8.924 (CI95%: 3.006–26.495), p<0.001] at the end of treatment, for a 12-month follow-up period. Patients' age, gender, comorbidities, history of trauma and surgery, clinical presentation of OAO, type of antimicrobial treatment (use of fluoroquinolones, carbapenems or colistin as monotherapy or in combination) as well as type of surgical intervention (explantation vs implant retention) were not found to significantly influence the patients' outcome. Overall, cure was assessed in 31 patients (58.5%). Death occurred in 7 patients, all older than 60, with failure of surgical treatment (p=0.016). These patients presented with many comorbidities (57%) and without difference in treatment outcome between XDR and MDR infection (p=0.114). Conclusion. Osteosynthesis-associated infections of the lower extremities caused by MDR/XDR GNB are a severe complication in orthopaedic surgery. The role of surgical treatment is independently associated with outcome regardless of the type of intervention (explantation or implant retention) and the type of antimicrobial treatment

Aims

Chronic osteomyelitis (COM) of the lower limb in adults can be surgically managed by either limb reconstruction or amputation. This scoping review aims to map the outcomes used in studies surgically managing COM in order to aid future development of a core outcome set.

Periprosthetic joint infection (PJI) is a major complication affecting >1% of all total knee arthroplasties, with compromise in patient function and high rates of morbidity and mortality. There are also major socioeconomic implications. Diagnosis is based on a combination of clinical features, laboratory tests (including serum and articular samples) and diagnostic imaging. Once confirmed, prompt management is required to prevent propagation of the infection and further local damage. Non-operative measures include patient resuscitation, systemic antibiotics, and wound management, but operative intervention is usually required. Definitive surgical management requires open irrigation and debridement of the operative site, with or without exchange arthroplasty in either a single or two-stage approach. In all options, the patient's fitness, comorbidities and willingness for further surgery should be considered, and full intended benefits and complications openly discussed. Late infection almost invariably leads to implant removal but early infections and acute haematogenous infections can be managed with implant retention – the challenge is to retain the original implant, having eradicated infection and restored full function. Debridement with component retention: Open debridement is indicated for acute postoperative infections or acute haematogenous infections with previously well-functioning joints. To proceed with this management option the following criteria must be met: short duration of symptoms - ideally less than 2–3 weeks but up to 6; well-fixed and well-positioned prostheses; healthy surrounding soft tissues. Open debridement is therefore not an appropriate course of management if symptoms have been prolonged – greater than 6 weeks, if there is a poor soft tissue envelope and scarring, or if a revision arthroplasty would be more appropriate due to loosening or malposition of the implant. It is well documented in the literature that there is an inverse relationship between the duration of symptoms and the success of a debridement. It is thought that as the duration of symptoms increases, other factors such as patient comorbidities, soft tissue status and organism virulence play an increasingly important role in determining the outcome. There is a caveat. Based on our learning in the hip, when we see an acute infection where periprosthetic implants are used, it is much easier to use this time-limited opportunity to remove the implants and the associated biofilm and do a single-stage revision instead of just doing a debridement and a change of insert. This will clearly be experience and prosthesis-dependent but if the cementless implant is easy to remove, then it should be explanted. One critical aspect of this procedure is to use one set of instruments and drapes for the debridement and to then implant the new mobile parts and close using fresh drapes and clean instruments. Units that have gained expertise in single-stage revision will find this easier to do. After a debridement, irrigation, and change of insert, patients continue on intravenous antibiotics until appropriate cultures are available. Our multidisciplinary team and infectious disease experts then take over and will dictate antibiotic therapy thereafter. This is typically continued for a minimum of three months. Patients are monitored clinically, serologically, and particularly in relation to nutritional markers and general wellbeing. Antibiotics are stopped when the patients reach a stable level and are well in themselves. All patients are advised to re-present if they have an increase in pain or they feel unwell

Aim. The aim of our study was to identify pathogens involved in septic knee arthritis after ACLR and to describe clinical features, treatment and outcome of infected patients. Methods. We conducted a retrospective observational study including all patients with ACLR infection in 3 orthopedic centers sharing the same infectious disease specialists. Results. During a seven-year period (2011–2017) we identified 74 infected patients among 9858 patients who had ACLR (incidence rate = 0.0075). Fourteen patients had polymicrobial infection. We identified 89 pathogens. Twenty four patients (34.4 %) were infected with S. aureus (27% of all isolates)(only one oxacillin-resistant strain). C. acnes was the second most frequent pathogen, identified in 14 patients (18.9%) (15.7% of all isolates). S. lugdunensis was identified in 9 patients (12.2%) (10.1% of all isolates). S. caprae was as frequent as S. epidermidis identified in 8 patients each (10.8%) (9 % of all isolates for each). No strain of S. lugdunensis and S. caprae was resistant to oxacillin, levofloxacin or rifampicin. Ten patients infected by C. acnes, 8 infected by S. lugdunensis, and 7 infected by S. caprae had an early acute infection. In all cases but one an arthroscopic lavage was performed, in 14 cases two lavages were required and in 4, 3 lavages. All patients infected by a strain susceptible to levofloxacin and rifampicin, including those with C. acnes, S. caprae and S. lugdunensis infection, were treated with an oral combination of levofloxacin and rifampicin, after a couple of days of IV empirical treatment with vancomycin and a broad spectrum beta-lactam. The median duration of treatment was 6 weeks. Seventy one patients were considered cured. Conclusions. To our knowledge this is the largest reported series of infection after ACLR. S. aureus is the main pathogen (27% of all strains). C. acnes, S. lugdunensis and S. caprae accounted for almost 35% of pathogens and 38% of infections. A conservative strategy consisting in arthroscopic lavage(s) and a 6-week treatment with levofloxacin and rifampicin was effective

Aim. Infected segmental defects are one of the most feared complications of open tibial fractures. This may be due to prolonged treatment time, permanent functional deficits and high reinfection and non-union rates. Distraction osteogenesis techniques such as Ilizarov acute shortening with bifocal relengthening (ASR) and bone transport (BT) are effective surgical treatment options in the tibia. The aim of this study was to compare ASL with bone transport in a consecutive series of complex tibial infected non-unions and osteomyelitis, for the reconstruction of segmental defects created at surgical resection of the infection. Method. In this single centre series, all patients with a segmental defect (>2cm) of the tibia after excision of infected non-union or osteomyelitis were eligible for inclusion. Based on clinical features, bone reconstruction was achieved with either ASR or BT using an Ilizarov fixator. We recorded the external fixation time (months), the external fixation index (EFI), comorbidities, Cierny-Mader or Weber-Cech classification, follow-up duration, time to union, number of operations and complications. Results. Overall, 43 patients with an infected tibial segmental defect were included. An ASR was performed in 19 patients with a median age of 40 years (range: 19 – 66 years). In this group, the median bone defect size was three cm (range: 2 – 5 cm); and the median frame time eight months (range: 5 – 16 months). BT was performed in 24 patients with a median age of 44 years (range: 21 – 70 years). The median bone defect size was six cm (range: 3 – 10 cm), and the median frame time ten months (range: 7 – 17 months). The EFI in the ASR group and the BT group measured 2.2 months/cm (range: 1.3 – 5.4 months/cm) and 1.9 months/cm (range: 0.8 – 2.8 months/cm), respectively. The comparison between the EFI of the ASL group and the BT group showed no statistically significant difference (p=0.147). Five patients of the ASR group (7 surgeries) and 19 patients of the BT group (23 surgeries) needed further unplanned surgery (p=0.001). Docking site surgery was significantly more frequent in BT; 66.7%, versus ASL; 5.3% (p=0.0001). Conclusion. Acute shortening/relengthening and bone transport are both safe and effective distraction osteogenesis techniques for the treatment of infected tibial non-unions. They share similar frame times per centimetre of defect. However, ASR demonstrated a statistically significant lower rate of unplanned surgeries

Aim. Data on Prosthetic joint infection (PJI) caused by multi-drug resistant (MDR) or XDR (extensively drug resistant) Gram negative bacteria (GNB) are limited. Treatment options are also restricted. We conducted a multi-national, multi-center assessment of clinical data and factors of outcome for these infections. Method. PJI were defined upon international guidelines. Data from 2000–2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy was collected retrospectively. Factors associated with treatment success were evaluated by logistic regression analysis. Results. A total of 133 PJI were evaluated. Female (n=84, 61.4%) and the elderly [mean age (+/-SD) 73 (12.7)] predominated. Diabetes mellitus was the most frequent comorbidity (n=42,32.1%) followed by rheumatoid arthritis (n=14,10.7). Most PJI were early infections (84.4 %). XDR accounted for 23 cases; half of them due to Pseudomonas aeruginosa. Prevalence of MDR or XDR GNB was not different between early and late PJIs (p=0.114). Overall, P.aeruginosa (n=25, 19.1%) was followed by Klebsiella spp (n=23,17.6%) and Enterobacter spp (n=22,16.8%). PJI was located at the hip (n=85 65.6%), knee (n=41,31.3%), shoulder (n=3,2.3%) and ankle (n=1, 0.8%). Clinical characteristics included soft tissue infection (66.4%), pain (51.1%), fever (32.1%) and sinus tract(29.8%). Surgery for PJIs consisted of DAIR (debridement, antibiotics and implant retention), (n=64, 49.6%), followed by explantation of the arthroplasty (n=32, 24.8%), two-stage revision (n=16, 12,4%), one stage revision (n=9, 7%), arthrodesis (n=2, 1.6%). Median duration of antibiotic therapy was 51 days (IQR 25–75: 40–90 days). Cure after treatment was assessed in 78 patients (58.6%). No-DAIR surgical procedures in PJIs were more likely to be successful compared to DAIR surgery (75.8% vs 50%, OR 3.13, 95% CI:1.47–6.70, p=0.003)both in early or late infections. Conclusions. PJI by MDR/XDR GNB affects female, the elderly with comorbidities and previous surgery for PJI. P.aeruginosa is frequent, mostly XRD. No-DAIR procedures have higher probability of treatment success than DAIR even in early infection. Despite surgery and long-term antimicrobial administration, treatment success was less than 60%, probably reflecting the lack of effective treatment options

Aims. The aim of this paper was to present the clinical features of patients with musculoskeletal sources of methicillin-sensitive Staphylococcus aureus (MSSA) septicaemia. Patients and Methods. A total of 137 patients presented with MSSA septicaemia between 2012 and 2015. The primary source of infection was musculoskeletal in 48 patients (35%). Musculoskeletal infection was considered the primary source of septicaemia when endocarditis and other obvious sources were excluded. All patients with an arthroplasty at the time were evaluated for any prosthetic involvement. . Results. The most common site of infection was the spine, which occurred in 28 patients (58%), and was associated with abscess formation in 16. Back pain was the presenting symptom in these patients, with a positive predictive value of 100%. A total of 24 patients had a total of 42 arthroplasties of the hip or knee in situ. Prosthetic joint infection occurred in six of these patients (25%). In five patients, the infection originated outside the musculoskeletal system. Three patients (6%) with MSSA septicaemia from a musculoskeletal sources died. . Conclusion. Amongst the musculoskeletal sources of MSSA septicaemia, the spine was the most commonly involved. We recommend an MRI scan of the whole spine and pelvis in patients with MSSA septicaemia with back pain, when the primary source of infection has not been identified or clinical examination is unreliable. Cite this article: Bone Joint J 2017;99-B:1545–51

Aim. Diagnosis of clavicle osteomyelitis (OM) is often difficult with delayed treatment due to the lower incidence of this disease. The present study aimed to summarize clinical experience with clinical features and treatment of clavicle OM. Method. We systematically searched the Pubmed database to identify studies regarding clinical characteristics and management of clavicle OM from 1980 to 2016, with publication language limited to English. Effective data were collected and pooled for analysis. Results. Altogether 69 reports comprising 188 cases were included for analysis. The average age of included patients was 24.95 years, 57.98% of whom were younger than 20 years. According to different etiologies, 86 cases (45.74%) were categorized as infectious OM with 102 cases (54.26%) as noninfectious. Of all the 102 noninfectious OM, 62.13% were diagnosed as chronic recurrent multifocal osteomyelitis (CRMO). The female-to-male ratio of infectious clavicle OM was 1.09, with 3.43 of noninfectious clavicle OM. The most common and earliest clinical symptom was pain, which occurred in 86.81% of the patients. Positive rate of serum erythrocyte sedimentation rate (ESR) was the highest among serum inflammatory biomarkers reported (92.47%). Staphylococcus aureus (46.94%) was the most frequently detected pathogen among patients with infectious clavicle OM. A total of 50 patients received surgical interventions finally (42.37 %). The most frequently used antibiotic was cephalosporin. Most cases achieved favorable outcomes (89.91%). Conclusions. Clavicle OM, classified as infectious and noninfectious, mostly occurred in the young people and females. The most frequently identified clinical symptom was pain. Despite different treatment strategies, most patients could achieve favorable outcomes

Introduction. Both measured resection technique and gap balancing technique have been important surgical concepts in total knee arthroplasty (TKA). Modified gap technique has been reported to be beneficial for the intra-operative soft tissue balancing in posterior-stabilizing (PS) -TKA. On the other hand, we have found joint distraction force changed soft tissue balance measurement and medial knee instability would be more likely with aiming at perfect ligament balance at extension in modified gap technique. The medial knee stability after TKA was reported to essential for post-operative clinical result. We have developed a new surgical concept named as “medial preserving gap technique” for varus type osteoarthritic (OA) knees to preserve medial knee stability and provide quantitative surgical technique using tensor device. The purpose of this study was to compare post-operative knee stability between medial preserving gap technique (MPGT) and measured resection technique (MRT) in PS-TKA. Material & Method. The subjects were 140 patients underwent primary unilateral PS-TKA for varus type OA knees. The surgical technique was MPGT in 70 patients and MRT in 70 patients. There were no significant differences between two groups in the pre-operative clinical features including age, sex, ROM and deformity. Originally developed off-set type tensor device was used to evaluate both center gap and varus angle with 40 lbs. of joint distraction force. The extension gap preparation was identical in both group. In MPGT group, femoral component size and external rotation angle were adjusted depending on the differences of center gaps and varus angles between extension and flexion before posterior femoral condylar osteotomy. The knee stabilities at extension and flexion were assessed by stress radiographies; varus-valgus stress test with extension and stress epicondylar view with flexion, at one-month and one-year after TKA. We measured joint opening distance (mm) at medial and lateral compartment at both knee extension and flexion. Joint opening distances were compared between two groups using unpaired t-test, and the difference between medial and lateral compartment in each group was compared using paired t- test (p<0.05). Results. Joint opening distances at medial compartments with both extension and flexion were significantly smaller than lateral in both groups. There were no significant differences in join opening distance between two groups at medial compartment, but those at lateral were significantly smaller in MPGT than MRT with both knee extension and flexion. Discussion. In the present study, we found MPGT resulted in equal postoperative medial knee stability as in MRT, and superior to MRT as for the lateral knee stability. This finding would be the result of different femoral external rotation angle and femoral component size selection between two groups. We used the difference of varus angle and center gap between flexion and extension for the femoral component size selection and external rotation angle in MPGT. Quantitative surgical concept; MPGT, was found to be safer and feasible gap technique in PS-TKA to preserving medial knee stability and control lateral laxity in varus type OA knee. MPGT would be an advantageous gap technique to enhance clinical outcome

Aims

Tuberculosis (TB) is one of the biggest communicable causes of mortality worldwide. While incidence in the UK has continued to fall since 2011, Bradford retains one of the highest TB rates in the UK. This study aims to examine the local disease burden of musculoskeletal (MSK) TB, by analyzing common presenting factors within the famously diverse population of Bradford.

Aim. Periprosthetic joint infections (PJI) are rare and require complex multi-disciplinary management. Successful single and two-stage revision procedures have been described. We describe the clinical features of this rare diagnosis from a single institution. Method. Patients were identified retrospectively from a prospectively collected institutional infection database. Clinical notes were evaluated for demographic, comorbid and clinical outcomes. The diagnosis of PJI, and any recurrence following treatment, was made in accordance with the Musculoskeletal Infection Society criteria. Failure was defined as recurrence of infection necessitating implant removal, excision arthroplasty or amputation. Results. Between 2005 and 2015, 25 patients were diagnosed with fungal PJIs involving hip(7) and knee(13) arthroplasties and endoprostheses(5). All included patients met the MSIS criteria for PJI. 88% had polymicrobial infections, 88% had multiply revised joints and 88% had coexisting multidrug resistant bacterial infections. Surgical protocol consisted of single stage (4) and two-stage (20) revision and excision arthroplasty. At mean three years follow-up (range 1 to 9 years) 19 patients were available for follow-up as six had died. At final follow-up there were 11 failures: one excision arthroplasty, two cases of recurrent PJI (8%) and 8 (32%) amputations. Conclusions. Revision specialists should maintain a low threshold for consideration of fungal PJI, particularly in the polymicrobial and multiply-revised cases. The detection of fungal organisms in multiorganism PJI is strongly associated with amputation and patients should be counselled at the outset