External Validation of the Joint-Specific Bone Involvement, Antimicrobial Options, Coverage of the Soft Tissues, and Host Status (JS-BACH) Classification for Predicting Outcome in Periprosthetic Joint Infections: A Cohort of 653 Patients.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication in hip and knee joint arthroplasty. The "Joint-Specific Bone Involvement, Antimicrobial Options, Coverage of the Soft Tissues, and Host Status (JS-BACH)" classification system was developed in 2021 to stratify the complexity of PJI, and more importantly, to act as a tool to guide referrals to specialist centers. The "JS-BACH" classification has not been validated in an external cohort. This study aimed to do so using a large prospective cohort from Australia and New Zealand. METHODS: We applied the JS-BACH classification to the Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort. This prospective study of newly diagnosed PJI collected 2-year outcome data from 653 participants enrolled in 27 hospitals. The definition of PJI treatment failure at 24 months was any of the following: death, clinical or microbiological signs of infection, destination prosthesis removed, or ongoing antibiotic use. Individual cases were classified as per JS-BACH into "1: uncomplicated" (n = 268), "2: complex" (n = 330), and "3: limited options" (n = 55). This cohort was similar to the original JS-BACH population in terms of baseline characteristics. However, there was a difference in complexity, with more debridement, antibiotics, and implant retention procedures, fewer revision procedures, and a higher proportion of uncomplicated patients in the PIANO cohort. RESULTS: The risk of treatment failure correlated strongly with the JS-BACH category, with odds ratios (95% confidence interval) for category 2 versus 1 of 1.75 (1.24 to 2.47) and for category 3 versus 1 of 7.12 (3.42 to 16.02). CONCLUSIONS: Despite the PIANO study population being less complicated than the original derivation cohort, the JS-BACH classification showed a clear association with treatment failure in this large external cohort.

Open surgical repair of hip abductor tendon tears.

INTRODUCTION: Tendinopathy and tendon tears of the gluteus medius and/or minimus (GMM) insertion at the greater trochanter are increasingly recognised internationally as a cause of recalcitrant lateral hip pain (LHP). The purpose of this study was to report the first Danish results of open surgical repair of GMM tears in female patients. METHODS: In this retrospective observational study, we included 67 women (68 hips) with a mean (95% confidence interval (CI)) age of 59 (56-61) years who underwent open GMM repair between September 2018 and June 2022. All cases had magnetic resonance imaging before surgery. Pre-, three- and 12-month post-operative testing included LHP (numerical rating scale 0-10), Copenhagen Hip and Groin Outcome Score (HAGOS), Oxford Hip Score (OHS), the EuroQol-Visual Analogue Scale (EQ-VAS) and the Global Rating of Change score (GROC). Responses on GROC were considered successful if patients scored "moderately better" to "very much better". Function of the lower limbs was assessed by the 30-second Chair-Stand-Test (CST). RESULTS: From pre-testing to 12-month follow-up, LHP at rest and during activity decreased significantly, all HAGOS subgroups improved by 27-35 points, the OHS improved from 22 to 35 points, the EQ-VAS improved from 52 to 72 points and the mean (95% CI) number of repetitions in the CST improved by 2.4 (1.4-3.3). Success on the GROC was reported by 79% of the patients. CONCLUSION: Open surgical repair of GMM tendon tears in women produced statistically significant improvements in patient-reported outcomes at one-year follow-up. FUNDING: None. TRIAL REGISTRATION: Not relevant.

Effect of single versus multiple prophylactic antibiotic doses on prosthetic joint infections following primary total hip arthroplasty in patients with osteoarthritis at public and private hospitals in Denmark: protocol for a nationwide cross-over, cluster randomised, non-inferiority trial [The Pro-Hip-Quality Trial].

INTRODUCTION: A feared complication after total hip arthroplasty (THA) is prosthetic joint infection (PJI), associated with high morbidity and mortality. Prophylactic antibiotics can reduce the risk of PJI. However, there is no consensus on the dosages and current recommendations are based on a low evidence level. The objective is to compare the effect of a single versus multiple doses of prophylactic antibiotics administered within 24 hours on PJI. METHODS AND ANALYSIS: The study is designed as a cross-over, cluster randomised, non-inferiority trial. All clinical centres use both antibiotic practices (1 year of each intervention). All Danish orthopaedic surgery departments will be involved: Based on quality databases, 2-year cohorts of approximately 20 000 primary THAs conducted at 39 public and private hospitals, will be included. INCLUSION CRITERIA: age ≥18 years, all indications for THA except patients operated due to acute or sequelae from proximal femoral or pelvic fractures or bone tumour or metastasis. The primary outcome is PJI within 90 days after primary THA. Secondary outcomes include (1) serious adverse events, (2) potential PJI, (3) length of hospitalisation stay, (4) cardiovascular events, (5) hospital-treated infections, (6) community-based antibiotic use, (7) opioid use and (8) use of acetaminophen and non-steroidal anti-inflammatory drugs. All outcome measures will be extracted from national databases. Analyses will be based on the intention-to-treat population. Non-inferiority will be shown if the upper limit of the two-sided 95% CI for the OR is less than 1.32 for the single dose as compared with multiple doses. The results will establish best practice on antibiotic prophylaxis dosages in the future. ETHICS AND DISSEMINATION: This study has been approved by Committees on Health Research Ethics for The Capital Region of Denmark (21069108) and The Danish Medicines Agency (2021091723). All results will be presented in peer-reviewed medical journals and international conferences. TRIAL REGISTRATION NUMBER: NCT05530551.

The value of sonication on orthopaedic implants in an everyday clinical setting - an exploratory study.

BACKGROUND: Sonication of removed orthopaedic implants in suspected implant-associated infections (IAI) is widely applied internationally. However, evaluation of the utility of sonication on all implants removed in everyday standard practice is scarce. This exploratory study was performed to evaluate the application of sonication fluid (SF) culture on removed orthopaedic implants, irrespective of the reason for removal. METHODS: Out of 100 removed orthopaedic implants collected between August 2019 and September 2020, 77 implants with availability of concurrent tissue culture samples were included in the study. Removed implants were categorized into a confirmed or suspected IAI group and a presumed aseptic group based on pre-operative diagnosis by the responsible surgeon. Implants were sonicated and SF culture performed under both aerobic and anaerobic conditions. The significance of all bacterial isolates was evaluated based on the CFU/mL cut-offs of the EBJIS guidelines, except for C. acnes where additional investigations were performed. RESULTS: The results of SF culture in the two groups were compared with their corresponding tissue cultures. Out of the 12 cases in the confirmed/suspected IAI group, SF culture was positive in 11 cases and had increased diagnostic yield in two (17%) cases compared to tissue culture. Increased diagnostic yield of SF compared to tissue culture was seen in seven (11%) of the 65 implants in the presumed aseptic group. If growth of Cutibacterium species isolates were interpreted based on EBJIS cut-off for SF culture instead of the study-specific criteria, then two isolates considered to represent infection might have been missed while three other isolates considered contaminants would have fallen under the 'infection confirmed' category in the EBJIS guidelines. CONCLUSION: Sonication with SF culture has increased diagnostic yield compared to tissue cultures in all implants irrespective of reason for removal. However, positive SF cultures with Cutibacterium species should always be interpreted with extreme care.

Shotgun sequencing of sonication fluid for the diagnosis of orthopaedic implant-associated infections with Cutibacterium acnes as suspected causative agent.

Orthopaedic implant-associated infections (OIAIs) due to Cutibacterium acnes can be difficult to diagnose. The aim of this pilot study was to determine if metagenomic next-generation sequencing (mNGS) can provide additional information to improve the diagnosis of C. acnes OIAIs. mNGS was performed on sonication fluid (SF) specimens derived from 24 implants. These were divided into three groups, based on culture results: group I, culture-negative (n = 4); group II, culture-positive for C. acnes (n = 10); and group III, culture-positive for other bacteria (n = 10). In group I, sequence reads from C. acnes were detected in only one SF sample, originating from a suspected case of OIAIs, which was SF and tissue culture-negative. In group II, C. acnes sequences were detected in 7/10 samples. In group III, C. acnes sequence reads were found in 5/10 samples, in addition to sequence reads that matched the bacterial species identified by culture. These samples could represent polymicrobial infections that were missed by culture. Taken together, mNGS was able to detect C. acnes DNA in more samples compared to culture and could be used to identify cases of suspected C. acnes OIAIs, in particular regarding possible polymicrobial infections, where the growth of C. acnes might be compromised due to a fast-growing bacterial species. However, since SF specimens are usually low-biomass samples, mNGS is prone to DNA contamination, possibly introduced during DNA extraction or sequencing procedures. Thus, it is advisable to set a sequence read count threshold, taking into account project- and NGS-specific criteria.

The effect of iliotibial band surgery at the hip: a systematic review.

BACKGROUND: Current literature presents a variety of surgical interventions aimed at modifying the iliotibial band (ITB) at the hip to relieve lateral hip pain (LHP). However, a focus towards the hip abductors as a main driver in LHP has evolved in the last decade, which could influence the indications for isolated ITB surgery. No previous review has been undertaken to evaluate isolated ITB surgery in LHP cases. PURPOSE: The purpose of this systematic review was to evaluate isolated ITB surgery in LHP patients in relation to pain, snapping, use of non-surgical treatments postoperatively, and repeated surgery. METHODS: The study was reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The study was registered in Prospero (CRD42021216707) prior to initiation. A systematic search of literature on PubMed and Embase as well as bibliography screening on adult patients undergoing isolated ITB surgery with or without additional bursectomies was performed. Due to the lack of reliable data, no meta-analysis was performed. RESULTS: A total of 21 studies (360 patients) were considered eligible for inclusion. The snapping and non-snapping group consisted of 150 and 210 patients, respectively. The mean follow-up time in the snapping group was 30 months and 19 months in the non-snapping group. Utilizing different surgical techniques, complete pain relief was not achieved in 12% of patients in the snapping group and 36% of the patients in the non-snapping group. In the snapping group, snapping was eliminated in 95% of patients, and five of 150 patients (3%) had repeated surgery. Eight of nine non-snapping studies reported information regarding repeated surgery, in which seven of 205 patients (3%) received repeated surgery. CONCLUSION: ITB surgery at the hip remains widely adopted, although only level 4 studies are available, and little information exists on the long-term clinical, as well as patient reported outcomes. Based on the available data, we found indication of a positive short-term outcome in LHP with snapping regarding elimination of snapping, pain reduction, reuse of non-surgical treatment, and repeated surgery. In LHP with no snapping, we found limited evidence supporting ITB surgery based on current literature.

Limited clinical utility of a machine learning revision prediction model based on a national hip arthroscopy registry.

PURPOSE: Accurate prediction of outcome following hip arthroscopy is challenging and machine learning has the potential to improve our predictive capability. The purpose of this study was to determine if machine learning analysis of the Danish Hip Arthroscopy Registry (DHAR) can develop a clinically meaningful calculator for predicting the probability of a patient undergoing subsequent revision surgery following primary hip arthroscopy. METHODS: Machine learning analysis was performed on the DHAR. The primary outcome for the models was probability of revision hip arthroscopy within 1, 2, and/or 5 years after primary hip arthroscopy. Data were split randomly into training (75%) and test (25%) sets. Four models intended for these types of data were tested: Cox elastic net, random survival forest, gradient boosted regression (GBM), and super learner. These four models represent a range of approaches to statistical details like variable selection and model complexity. Model performance was assessed by calculating calibration and area under the curve (AUC). Analysis was performed using only variables available in the pre-operative clinical setting and then repeated to compare model performance using all variables available in the registry. RESULTS: In total, 5581 patients were included for analysis. Average follow-up time or time-to-revision was 4.25 years (± 2.51) years and overall revision rate was 11%. All four models were generally well calibrated and demonstrated concordance in the moderate range when restricted to only pre-operative variables (0.62-0.67), and when considering all variables available in the registry (0.63-0.66). The 95% confidence intervals for model concordance were wide for both analyses, ranging from a low of 0.53 to a high of 0.75, indicating uncertainty about the true accuracy of the models. CONCLUSION: The association between pre-surgical factors and outcome following hip arthroscopy is complex. Machine learning analysis of the DHAR produced a model capable of predicting revision surgery risk following primary hip arthroscopy that demonstrated moderate accuracy but likely limited clinical usefulness. Prediction accuracy would benefit from enhanced data quality within the registry and this preliminary study holds promise for future model generation as the DHAR matures. Ongoing collection of high-quality data by the DHAR should enable improved patient-specific outcome prediction that is generalisable across the population. LEVEL OF EVIDENCE: Level III.

Biofilm formation and inflammatory potential of Staphylococcus saccharolyticus: A possible cause of orthopedic implant-associated infections.

Staphylococcus saccharolyticus, a coagulase-negative staphylococcal species, has some unusual characteristics for human-associated staphylococci, such as slow growth and its preference for anoxic culture conditions. This species is a relatively abundant member of the human skin microbiota, but its microbiological properties, as well as the pathogenic potential, have scarcely been investigated so far, despite being occasionally isolated from different types of infections including orthopedic implant-associated infections. Here, we investigated the growth and biofilm properties of clinical isolates of S. saccharolyticus and determined host cell responses. Growth assessments in anoxic and oxic conditions revealed strain-dependent outcomes, as some strains can also grow aerobically. All tested strains of S. saccharolyticus were able to form biofilm in a microtiter plate assay. Strain-dependent differences were determined by optical coherence tomography, revealing that medium supplementation with glucose and sodium chloride enhanced biofilm formation. Visualization of the biofilm by confocal laser scanning microscopy revealed the role of extracellular DNA in the biofilm structure. In addition to attached biofilms, S. saccharolyticus also formed bacterial aggregates at an early stage of growth. Transcriptome analysis of biofilm-grown versus planktonic cells revealed a set of upregulated genes in biofilm-embedded cells, including factors involved in adhesion, colonization, and competition such as epidermin, type I toxin-antitoxin system, and phenol-soluble modulins (beta and epsilon). To investigate consequences for the host after encountering S. saccharolyticus, cytokine profiling and host cell viability were assessed by infection experiments with differentiated THP-1 cells. The microorganism strongly triggered the secretion of the tested pro-inflammatory cyto- and chemokines IL-6, IL-8, and TNF-alpha, determined at 24 h post-infection. S. saccharolyticus was less cytotoxic than Staphylococcus aureus. Taken together, the results indicate that S. saccharolyticus has substantial pathogenic potential. Thus, it can be a potential cause of orthopedic implant-associated infections and other types of deep-seated infections.

Corrigendum: Risk of reoperation due to surgical site infection in 74,771 hip fracture patients: a Danish nationwide cohort study.

Corrigendum of Acta Orthop 2022; 93: 760-766. doi: https://doi.org/10.2340/17453674.2022.4580.

Risk of reoperation due to surgical site infection in 74,771 hip fracture patients: a Danish nationwide cohort study.

BACKGROUND AND PURPOSE: Surgical site infection (SSI) after hip fracture surgery is a feared condition. We examined the trend in incidence of reoperation due to SSI up to 1 year following hip fracture surgery from 2005 to 2016 and risk factors of SSI by age, sex, comorbidity, type of fracture, and surgery. PATIENTS AND METHODS: We conducted a population-based, nationwide cohort study using data from the Danish Multidisciplinary Hip Fracture Register (DMHFR). We included 74,771 patients aged 65 and up who underwent surgery from 2005 to 2016 for all types of hip fracture. We calculated net risk of reoperation using Kaplan­Meier method, and, with Cox regression, adjusted hazard ratios (HRs) with a 95% confidence interval (CI) for reoperation due to SSI. RESULTS: Overall, the 1-year net risk of reoperation due to SSI was 1.6%. The HR was higher for patients undergoing total/hemiarthroplasty surgery versus internal fixation (HR = 1.5; 95%CI 1.3­1.8) and lower for patients with per-/subtrochanteric fracture versus femoral neck fracture (HR = 0.6; CI 0.6­0.7). The risk of reoperation due to SSI decreased over time; HR was 0.7 (CI 0.5­0.8) for 2015­2016 compared with 2005­2006. Risk of reoperation decreased with increasing age; the HR was 0.8 (CI 0.7­1.0) in the more than 85-year-olds compared with 65­74-year-old patients. Charlson Comorbidity Index of ≥ 3 was associated with a higher risk of reoperation due to SSI, HR was 1.3 (CI 1.1­1.6). INTERPRETATION: The net risk of reoperations due to SSI in our study was lower than previously assumed. We identified several risk factors for increased risk of reoperation due to SSI, most noticeably treatment with arthroplasty vs. internal fixation, as well as younger age, high comorbidity burden, and femoral neck fracture diagnosis.

[Traumatic rupture of the gluteus minimus tendon].

An acute isolated tear of the gluteus minimus tendon after a traumatic event is very uncommon, and only a few cases have been reported worldwide. We present a case report of a 43-year-old woman with lateral hip pain after a scooter accident. Prior to the accident, she had no hip pain. Magnetic resonance imaging showed rupture of the gluteus minimus tendon attachment to the trochanter major. The patient underwent operative repair after non-surgical treatment had been attempted. The surgery was successful, and the patient fully recovered without any hip pain.

Low prevalence of trochanteric bursitis in patients with refractory lateral hip pain.

INTRODUCTION: Bursitis at the greater trochanter has historically been identified as a major pain generator in patients with lateral hip pain (LHP). We believe that hip abductor tendon pathology (HATP) plays an important and overlooked role in LHP. The purpose of this study was to evaluate the presence of isolated trochanteric bursitis on MRI in patients with refractory LHP. METHODS: The MRIs of 120 patients with LHP (94% women, median age 54 years) performed at our orthopaedic outpatient clinic between 2017 and 2020 were evaluated by two raters for trochanter-related pathologies, including HATP and bursitis. RESULTS: Two (2%) patients were registered with greater trochanteric bursitis with no relevant HATP, 30 (25%) patients had elements of inflammation (high-intensity signals) in the greater trochanteric bursa with relevant HATP. Five (4%) patients had relevant HATP with bursitis in the sub-gluteus minimus bursa with no bursitis in the greater trochanteric bursa. The remaining 83 (69%) patients had no sign of trochanter-related bursitis. CONCLUSION: Isolated trochanteric bursitis as the cause of refractory LHP appears to be rare. We believe that the presence of HATP in LHP has been severely underestimated and a shift in focus towards treatment of these structures is necessary. FUNDING: none. TRIAL REGISTRATION: According to current national legislation, no formal ethical approval was required for this study. The National Data Protection Agency approved the study (1-16-02-124-19).

Amplicon-Based Next-Generation Sequencing as a Diagnostic Tool for the Detection of Phylotypes of Cutibacterium acnes in Orthopedic Implant-Associated Infections.

The diagnosis of orthopedic implant-associated infections (OIAIs) caused by the slow-growing anaerobic bacterium Cutibacterium acnes is challenging. The mild clinical presentations of this low-virulent bacterium along with its ubiquitous presence on human skin and human-dominated environments often make it difficult to differentiate true infection from contamination. Previous studies have applied C. acnes phylotyping as a potential avenue to distinguish contamination from infection; several studies reported a prevalence of phylotypes IB [corresponding to type H in the single-locus sequence typing (SLST) scheme] and II (SLST type K) in OIAIs, while a few others found phylotype IA1 (more specifically SLST type A) to be abundant. However, phylotype determination has mainly been done in a culture-dependent manner on randomly selected C. acnes isolates. Here, we used a culture-independent amplicon-based next-generation sequencing (aNGS) approach to determine the presence and relative abundances of C. acnes phylotypes in clinical OIAI specimens. As amplicon, the SLST target was used, a genomic fragment that is present in all C. acnes strains known to date. The aNGS approach was applied to 30 sonication fluid (SF) samples obtained from implants removed during revision surgeries, including 17 C. acnes culture-positive and 13 culture-negative SF specimens. In 53% of the culture-positive samples, SLST types were identified: relative abundances were highest for K-type C. acnes, followed by H- and D-type C. acnes. Other types, including A- and C-type C. acnes that are more prevalent on human skin, had low relative abundances. The aNGS results were compared with, and confirmed by a culture-dependent approach, which included the isolation, whole genome sequencing (WGS) and phylotyping of 36 strains of C. acnes obtained from these SF samples. Besides serving as a powerful adjunct to identify C. acnes phylotypes, the aNGS approach could also distinguish mono- from heterotypic infections, i.e., infections caused by more than one phylotype of C. acnes: in eight out of nine culture-positive SF samples multiple C. acnes types were detected. We propose that the aNGS approach, along with the patient's clinical information, tissue and SF cultures and WGS, could help differentiate C. acnes contamination from true infection.

Early periprosthetic hip joint infection managed by cementless one-stage revision - a case series.

Background: Early periprosthetic hip joint infection (PJI) is traditionally treated with debridement, antibiotics, and implant retention (DAIR). However, infection control rates after DAIR-treated periprosthetic hip joint infection do not exceed 77 %. Cementless one-stage revision of chronic PJI by the Cementless One-stage Revision of Infected Hip Arthroplasty (CORIHA) protocol has been evaluated positively with a 91 % success rate. We wanted to evaluate the effectiveness of cementless one-stage revision following the CORIHA protocol for early PJI in elective primary total hip arthroplasty, regarding risk of re-operation with exchange of implants. Methods: We identified 18 patients in our center with early ( ≤ 6 -week postoperative) PJI after primary total hip arthroplasty (THA) treated with one-stage cementless revision in the period January 2012-March 2018. Treatment followed the CORIHA protocol. Primary outcome was retention of implants at the most recent follow-up. Patients were followed for a minimum of 3 years. Results: Mean follow-up time was 60 months (39-105). All patients retained their implants, but two required superficial soft tissue debridement due to persistent wound seepage. Conclusion: Cementless one-stage revision appears to be an effective treatment of early PJI after primary THA and at least an equal choice of treatment compared with DAIR. Whether the potential benefit of a lower re-revision rate for postoperative PJI outweighs the increased surgical complexity of the CORIHA procedure needs further evaluation.

Should all patients with a culture-negative periprosthetic joint infection be treated with antibiotics? : a multicentre observational study.

AIMS: The aim of this study was to analyze the prevalence of culture-negative periprosthetic joint infections (PJIs) when adequate methods of culture are used, and to evaluate the outcome in patients who were treated with antibiotics for a culture-negative PJI compared with those in whom antibiotics were withheld. METHODS: A multicentre observational study was undertaken: 1,553 acute and 1,556 chronic PJIs, diagnosed between 2013 and 2018, were retrospectively analyzed. Culture-negative PJIs were diagnosed according to the Muskuloskeletal Infection Society (MSIS), International Consensus Meeting (ICM), and European Bone and Joint Society (EBJIS) definitions. The primary outcome was recurrent infection, and the secondary outcome was removal of the prosthetic components for any indication, both during a follow-up period of two years. RESULTS: None of the acute PJIs and 70 of the chronic PJIs (4.7%) were culture-negative; a total of 36 culture-negative PJIs (51%) were treated with antibiotics, particularly those with histological signs of infection. After two years of follow-up, no recurrent infections occurred in patients in whom antibiotics were withheld. The requirement for removal of the components for any indication during follow-up was not significantly different in those who received antibiotics compared with those in whom antibiotics were withheld (7.1% vs 2.9%; p = 0.431). CONCLUSION: When adequate methods of culture are used, the incidence of culture-negative PJIs is low. In patients with culture-negative PJI, antibiotic treatment can probably be withheld if there are no histological signs of infection. In all other patients, diagnostic efforts should be made to identify the causative microorganism by means of serology or molecular techniques. Cite this article: Bone Joint J 2022;104-B(1):183-188.

The Framing of machine learning risk prediction models illustrated by evaluation of sepsis in general wards.

Problem framing is critical to developing risk prediction models because all subsequent development work and evaluation takes place within the context of how a problem has been framed and explicit documentation of framing choices makes it easier to compare evaluation metrics between published studies. In this work, we introduce the basic concepts of framing, including prediction windows, observation windows, window shifts and event-triggers for a prediction that strongly affects the risk of clinician fatigue caused by false positives. Building on this, we apply four different framing structures to the same generic dataset, using a sepsis risk prediction model as an example, and evaluate how framing affects model performance and learning. Our results show that an apparently good model with strong evaluation results in both discrimination and calibration is not necessarily clinically usable. Therefore, it is important to assess the results of objective evaluations within the context of more subjective evaluations of how a model is framed.

Diagnosis of orthopaedic-implant-associated infections caused by slow-growing Gram-positive anaerobic bacteria - a clinical perspective.

Slow-growing Gram-positive anaerobic bacteria (SGAB) such as Cutibacterium acnes are increasingly recognized as causative agents of implant-associated infections (IAIs) in orthopaedic surgeries. SGAB IAIs are difficult to diagnose because of their non-specific clinical and laboratory findings as well as the fastidious growth conditions required by these bacteria. A high degree of clinical suspicion and awareness of the various available diagnostic methods is therefore important. This review gives an overview of the current knowledge regarding SGAB IAI, providing details about clinical features and available diagnostic methodologies. In recent years, new methods for the diagnosis of IAI were developed, but there is limited knowledge about their usefulness in SGAB IAI. Further studies are required to determine the ideal diagnostic methodology to identify these infections so that they are not overlooked and mistakenly classified as aseptic failure.

Gluteal-related lateral hip pain.

INTRODUCTION: Lateral hip pain (LHP) due to tendon pathologies of insertion of the M. gluteus medius and minimus at the greater trochanter are often misdiagnosed and may lead to unrecognised disability. The purpose of this study was to evaluate pain and patient-reported outcomes in patients presenting with LHP in the context of a publicly financed healthcare system. METHODS: Data were collected from September 2017 to November 2020 at a regional teaching hospital. Inclusion criteria were clinical and MRI-verified hip abductor tendon pathology. Baseline testing included pain scoring (numerical rating scale, NRS), and the following patient-reported outcome scores: Copenhagen Hip and Groin Outcome Score (HAGOS), Oxford Hip Score (OHS) and EuroQol-Visual Analogue Scale (EQ-VAS). RESULTS: A total of 151 patients (94% women) with a median age of 55 years were included. The mean LHP (NRS 0-10) at rest, during activity and worst pain at any given time was 4, 7 and 9, respectively. The mean patient-reported outcome scores were HAGOS: pain 42.9, symptoms 49.8, activities of daily living 42.2, sport/recreation 28.1, participation in physical activities 25, quality of life 27.8; OHS 24; EQ-VAS 59.6. CONCLUSIONS: We found that patients with hip abductor tendon pathology display poor patient-reported outcomes comparable to those of patients suffering from severe hip osteoarthrosis. Further research into this patient group is warranted. The results are based on a heterogeneous study population in terms of variety of hip abductor tendon pathology and comorbidities and need to be interpreted as such. FUNDING: none. TRIAL REGISTRATION: According to current Danish law, no formal ethical approval was required for this study. The National Data Protection Agency approved the study (1-16-02-125-19).

Atypical femoral fracture as the cause of greater trochanteric pain syndrome - a case report.

Greater trochanteric pain syndrome may be caused by atypical femoral fractures, and this should be taken into consideration in the diagnostic workout. A 63-year-old woman was referred to our orthopedic outpatient hip clinic with a history of greater trochanteric pain syndrome without known trauma for 1 year. Initially X-ray of the hip and magnetic resonance imaging were found without pathology, and she was given a diagnosis of gluteus medius tendinopathy. As physiotherapy and steroid injections did not resolve her pain, a second look on the magnetic resonance imaging and X-ray revealed a discrete atypical femoral fracture in the lateral cortex with the presence of an isolated Looser zone, which were attributed to her pain syndrome. Two years after onset of symptoms, and with no pain relief on medical treatment, she was treated with an intramedullary nail. One-year postoperative the patient was pain free. This case emphasizes the important utility of magnetic resonance imaging in refractory greater trochanteric pain syndrome.