MicroRNA expression analysis in peripheral blood and soft-tissue of patients with periprosthetic hip infection.

Aims: Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients. Methods: This was a prospective pilot study, including 24 patients divided into three groups, with eight patients each undergoing revision of their hip arthroplasty due to aseptic reasons, and low- and high-grade PJI, respectively. The number of intraoperative samples and the incidence of positive cultures were recorded for each patient. Additionally, venous blood samples and periarticular tissue samples were collected from each patient to determine miRNA expressions between the groups. MiRNA screening was performed by small RNA-sequencing using the miRNA next generation sequencing (NGS) discovery (miND) pipeline. Results: Overall, several miRNAs in plasma and tissue were identified to be progressively deregulated according to ongoing PJI. When comparing the plasma samples, patients with a high-grade infection showed significantly higher expression levels for hsa-miR-21-3p, hsa-miR-1290, and hsa-miR-4488, and lower expression levels for hsa-miR-130a-3p and hsa-miR-451a compared to the aseptic group. Furthermore, the high-grade group showed a significantly higher regulated expression level of hsa-miR-1260a and lower expression levels for hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-148b-5p, hsa-miR-301a-3p, hsa-miR-451a, and hsa-miR-454-3p compared to the low-grade group. No significant differences were found between the low-grade and aseptic groups. When comparing the tissue samples, the high-grade group showed significantly higher expression levels for 23 different miRNAs and lower expression levels for hsa-miR-2110 and hsa-miR-3200-3p compared to the aseptic group. No significant differences were found in miRNA expression between the high- and low-grade groups, as well as between the low-grade and aseptic groups. Conclusion: With this prospective pilot study, we were able to identify a circulating miRNA signature correlating with high-grade PJI compared to aseptic patients undergoing hip arthroplasty revision. Our data contribute to establishing miRNA signatures as potential novel diagnostic and prognostic biomarkers for PJI.

Re-revision and mortality rate following revision total hip arthroplasty for infection.

Aims: This study compares the re-revision rate and mortality following septic and aseptic revision hip arthroplasty (rTHA) in registry data, and compares the outcomes to previously reported data. Methods: This is an observational cohort study using data from the German Arthroplasty Registry (EPRD). A total of 17,842 rTHAs were included, and the rates and cumulative incidence of hip re-revision and mortality following septic and aseptic rTHA were analyzed with seven-year follow-up. The Kaplan-Meier estimates were used to determine the re-revision rate and cumulative probability of mortality following rTHA. Results: The re-revision rate within one year after septic rTHA was 30%, and after seven years was 34%. The cumulative mortality within the first year after septic rTHA was 14%, and within seven years was 40%. After multiple previous hip revisions, the re-revision rate rose to over 40% in septic rTHA. The first six months were identified as the most critical period for the re-revision for septic rTHA. Conclusion: The risk re-revision and reinfection after septic rTHA was almost four times higher, as recorded in the ERPD, when compared to previous meta-analysis. We conclude that it is currently not possible to assume the data from single studies and meta-analysis reflects the outcomes in the 'real world'. Data presented in meta-analyses and from specialist single-centre studies do not reflect the generality of outcomes as recorded in the ERPD. The highest re-revision rates and mortality are seen in the first six months postoperatively. The optimization of perioperative care through the development of a network of high-volume specialist hospitals is likely to lead to improved outcomes for patients undergoing rTHA, especially if associated with infection.

Success Rate After 2-Stage Spacer-Free Total Hip Arthroplasty Exchange and Risk Factors for Reinfection: A Prospective Cohort Study of 187 Patients.

BACKGROUND: Two-stage prosthesis exchange is the treatment of choice for chronic periprosthetic joint infection (PJI) of a total hip arthroplasty (THA), especially when the bone and surrounding soft tissues are compromised or difficult-to-treat pathogens are implicated. The aims of our study were as follows: (1) to determine the outcome of 2-stage prosthesis exchange for the treatment of PJI after THA and (2) to determine the risk factors for reinfection leading to subsequent revision surgeries after reimplantation. METHODS: We prospectively enrolled 187 consecutive patients who underwent a 2-stage THA exchange with resection arthroplasty for PJI from 2013 to 2019. The mean (± SD) duration of follow-up was 54.2 ± 24.9 months (range, 36 to 96), and the mean interval until reimplantation was 9.8 ± 8.9 weeks (range, 2 to 38). All patients remained in a spacer-free girdlestone situation between the 2 stages of treatment. Patients who remained infection-free after their 2-stage treatment were considered to have achieved treatment success. RESULTS: The overall success rate was 85.6%. The cumulative probability of reinfection was 11.5% after one year and 14% after 2 years after reimplantation. High virulence or difficult-to-treat pathogens were significant and independent risk factors for reinfection (HR [hazard ratio] = 3.71, 95% CI [confidence interval]: 1.47 to 9.36, P = .006 and HR = 3.85, 95% CI: 1.73 to 8.57, respectively, P = .001), as was previous 2-stage hip prosthesis exchange (HR = 3.58, 95% CI: 1.33 to 9.62, P = .01). Overall reoperation and revision rates were 26.2 and 16.6%, respectively. Re-infected patients had an 80% higher probability of reoperation than noninfected ones (P < .001, log-rank = 102.6), and they were 55% more likely to undergo revision surgery during their follow-up (P < .001, log-rank = 55.4). CONCLUSIONS: Reinfection rates after 2-stage spacer-free THA revision for PJI still remain high but are comparable to those including cement spacers. Patients who have had prior failed 2-stage implant exchanges or are infected by high-grade or difficult-to-treat pathogens are at high risk for treatment failure.

Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow.

Bone marrow plasma cells (BMPC) are the correlate of humoral immunity, consistently releasing antibodies into the bloodstream. It remains unclear if BMPC reflect different activation environments or maturation of their precursors. Here we define human BMPC heterogeneity and track the recruitment of antibody-secreting cells (ASC) from SARS-CoV-2 vaccine immune reactions to the bone marrow (BM). Trajectories based on single-cell transcriptomes and repertoires of peripheral and BM ASC reveal sequential colonisation of BMPC compartments. In activated B cells, IL-21 suppresses CD19 expression, indicating that CD19low-BMPC are derived from follicular, while CD19high-BMPC originate from extrafollicular immune reactions. In primary immune reactions, both CD19low- and CD19high-BMPC compartments are populated. In secondary immune reactions, most BMPC are recruited to CD19high-BMPC compartments, reflecting their origin from extrafollicular reactivations of memory B cells. A pattern also observable in vaccinated-convalescent individuals and upon diphtheria/tetanus/pertussis recall-vaccination. Thus, BMPC diversity reflects the evolution of a given humoral immune response.

An interpretable data-driven prediction model to anticipate scoliosis in spinal muscular atrophy in the era of (gene-) therapies.

5q-spinal muscular atrophy (SMA) is a neuromuscular disorder (NMD) that has become one of the first 5% treatable rare diseases. The efficacy of new SMA therapies is creating a dynamic SMA patient landscape, where disease progression and scoliosis development play a central role, however, remain difficult to anticipate. New approaches to anticipate disease progression and associated sequelae will be needed to continuously provide these patients the best standard of care. Here we developed an interpretable machine learning (ML) model that can function as an assistive tool in the anticipation of SMA-associated scoliosis based on disease progression markers. We collected longitudinal data from 86 genetically confirmed SMA patients. We selected six features routinely assessed over time to train a random forest classifier. The model achieved a mean accuracy of 0.77 (SD 0.2) and an average ROC AUC of 0.85 (SD 0.17). For class 1 'scoliosis' the average precision was 0.84 (SD 0.11), recall 0.89 (SD 0.22), F1-score of 0.85 (SD 0.17), respectively. Our trained model could predict scoliosis using selected disease progression markers and was consistent with the radiological measurements. During post validation, the model could predict scoliosis in patients who were unseen during training. We also demonstrate that rare disease data sets can be wrangled to build predictive ML models. Interpretable ML models can function as assistive tools in a changing disease landscape and have the potential to democratize expertise that is otherwise clustered at specialized centers.

Dual-mobility bearings reduce instability but may not be the only answer in revision total hip arthroplasty for recurrent dislocation.

Aims: There is little information in the literature about the use of dual-mobility (DM) bearings in preventing re-dislocation in revision total hip arthroplasty (THA). The aim of this study was to compare the use of DM bearings, standard bearings, and constrained liners in revision THA for recurrent dislocation, and to identify risk factors for re-dislocation. Methods: We reviewed 86 consecutive revision THAs performed for dislocation between August 2012 and July 2019. A total of 38 revisions (44.2%) involved a DM bearing, while 39 (45.3%) and nine (10.5%) involved a standard bearing and a constrained liner, respectively. Rates of re-dislocation, re-revision for dislocation, and overall re-revision were compared. Radiographs were assessed for the positioning of the acetabular component, the restoration of the centre of rotation, leg length, and offset. Risk factors for re-dislocation were determined by Cox regression analysis. The modified Harris Hip Scores (mHHSs) were recorded. The mean age of the patients at the time of revision was 70 years (43 to 88); 54 were female (62.8%). The mean follow-up was 5.0 years (2.0 to 8.75). Results: DM bearings were used significantly more frequently in elderly patients (p = 0.003) and in hips with abductor deficiency (p < 0.001). The re-dislocation rate was 13.2% for DM bearings compared with 17.9% for standard bearings, and 22.2% for constrained liners (p = 0.432). Re-revision-free survival for DM bearings was 84% (95% confidence interval (CI) 0.77 to 0.91) compared with 74% (95% CI 0.67 to 0.81) for standard articulations, and 67% (95% CI 0.51 to 0.82) for constrained liners (p = 0.361). Younger age (hazard ratio (HR) 0.92 (95% CI 0.85 to 0.99); p = 0.031), lower comorbidity (HR 0.44 (95% CI 0.20 to 0.95); p = 0.037), smaller heads (HR 0.80 (95% CI 0.64 to 0.99); p = 0.046), and retention of the acetabular component (HR 8.26 (95% CI 1.37 to 49.96); p = 0.022) were significantly associated with re-dislocation. All DM bearings which re-dislocated were in patients with abductor muscle deficiency (HR 48.34 (95% CI 0.03 to 7,737.98); p = 0.303). The radiological analysis did not reveal a significant relationship between restoration of the geometry of the hip and re-dislocation. The mean mHHSs significantly improved from 43 points (0 to 88) to 67 points (20 to 91; p < 0.001) at the final follow-up, with no differences between the types of bearing. Conclusion: We found that the use of DM bearings reduced the rates of re-dislocation and re-revision in revision THA for recurrent dislocation, but did not guarantee stability. Abductor deficiency is an important predictor of persistent instability.

Accurate surgical posterior tibial slope alteration can be achieved in total knee arthroplasty regardless of surgeon skill level or local soft tissue thickness-A retrospective radiograph-based study.

PURPOSE: To retrospectively report on the impact of local soft tissue thickness and surgeon skill level on the accuracy of surgical posterior tibial slope (PTS) alteration achieved in patients undergoing total knee arthroplasty (TKA) utilising lateral knee radiographs. METHODS: Pre- and postoperative radiographs of 82 patients undergoing primary TKA using conventional mechanical alignment technique were measured by two observers and subjected to quality criteria for accurate measurement of the PTS. All patients underwent a standardised surgical approach for PTS alteration: cruciate-retaining (CR) cases with preoperative PTS ≤ 10° were set for reconstruction of the preoperative PTS. Cases indicated for posterior-stabilised (PS) design and/or with a preoperative PTS > 10° were set for 3° of postoperative PTS. Pretibial subcutaneous fat (PSF) and surgeon skill level were analysed for their predictive quality regarding the accuracy of surgical PTS alteration achieved. RESULTS: The overall mean postoperative PTS was significantly lower than the preoperative values (6.2°, SD 2.7 vs. 7.7°, SD 3.2; p = 0.002103). Neither local soft tissue thickness, namely PSF, nor surgeon skill level was found to be a predictor of the accuracy of surgical PTS alteration achieved. Among cases set for PTS reconstruction, 25.9% and 42.6% achieved a postoperative PTS within ±1° and ±2° of preoperative values, respectively. In patients with a PTS > 10° or those indicated for PS design, slope reduction was achieved with a mean postoperative PTS of 6.5°. Furthermore, 14.3% and 32.1% of cases were within ±1° and ±2° of 3, respectively. CONCLUSION: This study demonstrates that accurate surgical alteration of the PTS is possible in TKA regardless of local knee soft tissue thickness or surgeon skill level. This proves the clinical feasibility of both targeted reduction as well as reconstruction of the PTS in TKA. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

International Delphi Study on Wound Closure and Incision Management in Joint Arthroplasty Part 2: Total Hip Arthroplasty.

BACKGROUND: This modified Delphi study aimed to develop a consensus on optimal wound closure and incision management strategies for total hip arthroplasty (THA). Given the critical nature of wound care and incision management in influencing patient outcomes, this study sought to synthesize evidence-based best practices for wound care in THA procedures. METHODS: An international panel of 20 orthopedic surgeons from Europe, Canada, and the United States evaluated a targeted literature review of 18 statements (14 specific to THA and 4 related to both THA and total knee arthroplasty). There were 3 rounds of anonymous voting per topic using a modified 5-point Likert scale with a predetermined consensus threshold of ≥ 75% agreement necessary for a statement to be accepted. RESULTS: After 3 rounds of voting, consensus was achieved for all 18 statements. Notable recommendations for THA wound management included (1) the use of barbed sutures over non-barbed sutures (shorter closing times and overall cost savings); (2) the use of subcuticular sutures over skin staples (lower risk of superficial infections and higher patient preferences, but longer closing times); (3) the use of mesh-adhesives over silver-impregnated dressings (lower rate of wound complications); (4) for at-risk patients, the use of negative pressure wound therapy over other dressings (lower wound complications and reoperations, as well as fewer dressing changes); and (5) the use of triclosan-coated sutures (lower risk of surgical site infection) over standard sutures. CONCLUSIONS: Through a structured modified Delphi approach, a panel of 20 orthopedic surgeons reached consensus on all 18 statements pertaining to wound closure and incision management in THA. This study provides a foundational framework for establishing evidence-based best practices, aiming to reduce variability in patient outcomes and to enhance the overall quality of care in THA procedures.

The Subjective Hip Value is a Valid, Reliable, and Responsive Instrument for Assessing Hip Function in Primary Total Hip Arthroplasty.

BACKGROUND: Patient-reported outcome measures are essential tools in clinical decision-making and research. Multi-item scores like the modified Harris Hip Score (mHHS) are time-consuming to collect and evaluate. The subjective hip value (SHV), as a single-item value, assesses hip function with one question: "What is the overall percent value of your hip if a completely normal hip represents 100%?". The aims of our study were to assess the psychometric properties, and thus validity, reliability, and responsiveness; and to define the minimal clinically important difference (MCID) of the SHV in patients undergoing total hip arthroplasty. METHODS: A total of 137 consecutive patients who underwent primary total hip arthroplasty between June 2020 and August 2021 were prospectively enrolled. A SHV and mHHS were collected preoperatively and at follow-ups (6 weeks, 3 months, 6 months, and 1 year). Validity, reliability, responsiveness, MCID, and floor/ceiling effects were evaluated. RESULTS: There was a significant correlation between SHV and mHHS (P = .001) preoperatively (rs = 0.532), 6 weeks (rs = 0.649), 3 months (rs = 0.765), 6 months (rs = 0.854), and after 1 year (rs = 0.879). Test-retest reliability (rs = 0.74; P = .001) and responsiveness (rs = 0.24; P = .007) showed significant correlations. The MCID for SHV was 10.06%. Floor- and ceiling-effects were comparable to the mHHS. CONCLUSIONS: The SHV is a valid, reliable, and responsive single-item score for the assessment of hip joint function in arthroplasty patients. It can detect clinically relevant changes in joint function and is easy to collect and interpret, which justifies its implementation in clinical practice.

Influence of the type of stem and its fixation on revision and immediate postoperative mortality in elective total hip arthroplasty.

Aims: Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. Methods: A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem. Results: The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades. Conclusion: In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA.

Outcomes and Return-to-Sports Rates in Patients With Borderline Hip Dysplasia After Periacetabular Osteotomy: A Case Series With 5-Year Follow-up.

BACKGROUND: The optimal surgical approach in patients with borderline hip dysplasia (BHD) remains controversial. Both hip arthroscopy and periacetabular osteotomy (PAO) are commonly employed in this patient population. Those who participate in sports want to resume and maintain sports activities after surgery, and the ability to do so plays an important role in the choice of a treatment method. To our knowledge, no previous study has assessed return-to-sports rates and activity levels in patients with BHD after PAO. PURPOSE: To assess return-to-sports rates and postoperative activity levels as measured by the University of California, Los Angeles (UCLA), activity scale as well as patient-reported outcome measures. Also to assess changes in sports activity both qualitatively and quantitatively as well as underlying reasons for these changes. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We conducted a retrospective analysis of prospectively collected data from 55 hips in 52 patients with BHD who underwent PAO between January 2015 and June 2017. Return-to-sports rates, UCLA activity scores, International Hip Outcome Tool-12 scores, Subjective Hip Value scores, Hip disability and Osteoarthritis Outcome Score subscores, sports practiced, frequency and duration of sports activity, and postoperative changes as well as underlying reasons were recorded. RESULTS: The mean follow-up was 62.8 ± 9.0 months. The return-to-sports rate among preoperatively active patients was 92.5%. Most patients resumed sports activity after 6 months (50%) or after 3 to 6 months (37.5%). The UCLA activity score improved significantly (from 5.2 ± 2.4 to 7.0 ± 1.8; P < .001). The International Hip Outcome Tool-12, Subjective Hip Value, and Hip disability and Osteoarthritis Outcome Score scores also improved significantly (all, P < .001). Changes in sports activity occurred in 34.5% of cases after PAO. Significantly more patients engaged in low-impact sports postoperatively. Participation in high-impact sports did not decrease significantly. Reasons for changes were both hip related and non-hip related. Quantitatively, patients were able to significantly increase both the frequency (P = .007) and duration (P = .007) of sports activity. CONCLUSION: The return-to-sports rate in patients with BHD after PAO was high at over 92%. Most patients returned to sports after a period of 6 months or 3 to 6 months. Overall, activity levels and hip function improved after PAO. A number of patients adjusted their sports activity after PAO. Although more patients engaged in low-impact sports, participation in high-impact sports was maintained postoperatively. The results of this study may help both patients and orthopaedic surgeons in deciding on the best surgical procedure in the setting of BHD.

International Delphi Study on Wound Closure and Dressing Management in Joint Arthroplasty: Part 1: Total Knee Arthroplasty.

BACKGROUND: The purpose of this modified Delphi study was to obtain consensus on wound closure and dressing management in total knee arthroplasty (TKA). METHODS: The Delphi panel included 20 orthopaedic surgeons from Europe and North America. There were 26 statements identified using a targeted literature review. Consensus was developed for the statements with up to three rounds of anonymous voting per topic. Panelists ranked their agreement with each statement on a five-point Likert scale. An a priori threshold of ≥ 75% was required for consensus. RESULTS: All 26 statements achieved consensus after three rounds of anonymous voting. Wound closure-related interventions that were recommended for use in TKA included: 1) closing in semi-flexion versus extension (superior range of motion); 2) using aspirin for venous thromboembolism prophylaxis over other agents (reduces wound complications); 3) barbed sutures over non-barbed sutures (lower wound complications, better cosmetic appearances, shorter closing times, and overall cost savings); 4) mesh-adhesives over other skin closure methods (lower wound complications, higher patient satisfaction scores, lower rates of readmission); 5) silver-impregnated dressings over standard dressings (lower wound complications, decreased infections, fewer dressing changes); 6) in high-risk patients, negative pressure wound therapy over other dressings (lower wound complications, decreased reoperations, fewer dressing changes); and 7) using triclosan-coated over non-antimicrobial-coated sutures (lower risks of surgical site infection). CONCLUSIONS: Using a modified Delphi approach, the panel achieved consensus on 26 statements pertaining to wound closure and dressing management in TKA. This study forms the basis for identifying critical evidence supported by clinical practice for wound management to help reduce variability, advance standardization, and ultimately improve outcomes during TKA. The results presented here can serve as the foundation for knowledge, education, and improved clinical outcomes for surgeons performing TKAs.

Bilateral simultaneous knee arthroplasty shows comparable early outcome and complication rate as staged bilateral knee arthroplasty for patients scored ASA 1-3 if performed by a high-volume surgeon: a retrospective cohort study of 127 cases.

BACKGROUND AND PURPOSE: The study compares early outcomes after simultaneous and staged knee arthroplasty in patients with bilateral knee osteoarthritis (OA) to evaluate whether simultaneous bilateral TKA shows comparable early outcomes and complication rates to staged bilateral TKA. METHODS: A retrospective cohort study including all patients scheduled for primary TKA for bilateral knee OA (n = 127) was conducted. Patients received either simultaneous (n = 53, 41.7%) or staged (n = 74, 58.3%) bilateral TKA by a single, high-volume surgeon-depending on their individual preference. Demographic data, haemoglobin drop (Hb), length of stay (LOS), operation time, 30-day complication rate and achievement of rehabilitation key points were evaluated. RESULTS: There was no difference between the groups concerning age, sex, BMI or complication rate. ASA scoring was better in the simultaneous group [2.2, (15.1% ASA 1, 49.1% ASA 2, 35.8% ASA 3) vs. 2.4 (2.7% ASA 1, 51.4% ASA 2, 45.9% ASA 3)]. Average LOS was 7.8 ± 2.1 days for simultaneous TKA, 7.4 ± 1.7 days for single procedure of staged group (p < 0.453) and 14.7 ± 3.1 days if combined (p < 0.001). Cumulative Hb loss was significantly higher in the staged group (3.8 ± 1.2 g/dl vs. 2.4 ± 0.8 g/dl, p < 0.001). Detailed comparison of early outcome parameters between staged and simultaneous procedure depending on ASA score only revealed slightly slower assessment of stairs (p < 0.001) and increased Hb drop per surgery in case of simultaneous procedure (p < 0.011) if ASA score was ≥ 2. Only patients scored ASA 3 demonstrated a significant longer LOS per procedure in simultaneous group (8.5 ± 2.4 vs.7.3 ± 1.6 days, p = 0.034). INTERPRETATION: Simultaneous bilateral TKA results in comparable early outcome and complication rate than staged bilateral procedure-even for patients scored ASA 3. LEVEL OF EVIDENCE: Level IV.

[Acute postoperative infections after dual head arthroplasty in geriatric patients]. / Akute postoperative Infektion nach Duokopfprothesenimplantation beim geriatrischen Patienten.

Acute periprosthetic joint infections (PJI) after dual head arthroplasty represent a major challenge with a 1-year mortality rate up to 50% in the mostly multimorbid geriatric patient collective. Due to the limited possibilities of preoperative patient optimization, infection rates of up to 9% have been reported, which is significantly higher than in elective arthroplasty. A therapeutic gold standard has not yet been established due to the heterogeneous study situation and the lack of prospective randomized studies. The most promising therapeutic option currently appears to be a single-stage stem replacement in combination with implantation of a cup component (conversion to total hip arthroplasty, infection eradication in up to 100%). An approach of débridement, antibiotics, implant retention (DAIR) alone shows significantly poorer success rates (16-82%). Surgical treatment should always be followed by antibiotic treatment with a total duration of 12 weeks. In addition to the established perioperative antibiotic prophylaxis, the use of antibiotic-loaded bone cement seems to be superior to cementless stem fixation in preventing PJI in dual head arthroplasty.

Periacetabular osteotomy for symptomatic hip dysplasia in middle aged patients: does age alone matter?

BACKGROUND: Conflicting evidence exists regarding outcomes in middle-aged patients undergoing periacetabular osteotomy (PAO) for symptomatic developmental dysplasia of the hip (DDH). AIMS: To compare patient reported outcomes (PROMs) of middle-aged PAO patients with younger patient groups. METHODS: Retrospective analysis of prospectively collected data of PAO patients between 01/2015 and 06/2017 at a single orthopedic university center with a primary diagnosis of symptomatic DDH. The cohort was divided into four age groups and compared: < 20, 20-30, 30-40 and > 40 years. Joint function was assessed using iHOT-12, mHHS and SHV. Activity level was assessed using UCLA Activity score. Patient satisfaction and pain were assessed on the numerical rating scale 0-10. Conversion rates to THA were assessed. RESULTS: Out of 202 PAOs, 120 cases with complete data were included. Mean follow-up was 63 months (range 47-81 months). Eighteen patients were < 20 years old, 54 were 20-30 years, 37 were 30-40 years, 11 patients were older than 40. No significant differences were observed for preoperative or postoperative iHOT-12 (p = 0.898; p = 0.087), mHHS (p = 0.878; p = 0.103), SHV (p = 0.602; p = 0.352) or UCLA (p = 0.539; p = 0.978) between groups. Improvement deltas were also not significantly different for all PROMs. Postoperative patient satisfaction was similar between groups (p = 0.783). CONCLUSION: Patients with symptomatic DDH may benefit from PAO even at middle age with similar outcomes and pre- to postoperative improvements as younger age groups. Indication should be based on biological age and preoperative joint condition rather than age.

Loading of the Hip and Knee During Swimming: An in Vivo Load Study.

BACKGROUND: Swimming is commonly recommended as postoperative rehabilitation following total hip arthroplasty (THA) and total knee arthroplasty (TKA). So far, in vivo hip and knee joint loads during swimming remain undescribed. METHODS: In vivo hip and knee joint loads were measured in 6 patients who underwent THA and 5 patients who underwent TKA with instrumented joint implants. Joint loads, including the resultant joint contact force (F Res ), torsional moment around the femoral shaft axis or the tibial axis (M Tors ), bending moment at the middle of the femoral neck (M Bend ), torsional moment around the femoral neck axis (M Tne ), and medial force ratio (MFR) in the knee, were measured during breaststroke swimming at 0.5, 0.6, and 0.7 m/s and the breaststroke and crawl kicks at 0.5 and 1.0 m/s. RESULTS: The ranges of the median maximal F Res were 157% to 193% of body weight for the hip and 93% to 145% of body weight for the knee during breaststroke swimming. Greater maxima of F Res (hip and knee), M Tors (hip and knee), M Bend (hip), and M Tne (hip) were observed with higher breaststroke swimming velocities, but significance was only identified between 0.5 and 0.6 m/s in F Res (p = 0.028), M Tors (p = 0.028), and M Bend (p = 0.028) and between 0.5 and 0.7 m/s in F Res (p = 0.045) in hips. No difference was found in maximal MFR between different breaststroke swimming velocities. The maximal F Res was significantly positively correlated with the breaststroke swimming velocity (hip: r = 0.541; p < 0.05; and knee: r = 0.414; p < 0.001). The maximal F Res (hip and knee) and moments (hip) were higher in the crawl kick than in the breaststroke kick, and a significant difference was recognized in F Res Max for the hip: median, 179% versus 118% of body weight (p = 0.028) for 0.5 m/s and 166% versus 133% of body weight (p = 0.028) for 1.0 m/s. CONCLUSIONS: Swimming is a safe and low-impact activity, particularly recommended for patients who undergo THA or TKA. Hip and knee joint loads are greater with higher swimming velocities and can be influenced by swimming styles. Nevertheless, concrete suggestions to patients who undergo arthroplasty on swimming should involve individual considerations. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Microbial spectrum, patient-specific factors, and diagnostics in implant-related postoperative spondylodiscitis.

Aims: Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date. Methods: Patients treated for IPOS from January 2006 to December 2020 were included. Patient demographics, parameters upon admission and discharge, radiological imaging, and microbiological results were retrieved from medical records. CT and MRI were analyzed for epidural, paravertebral, and intervertebral abscess formation, vertebral destruction, and endplate involvement. Pathogens were identified by CT-guided or intraoperative biopsy, intraoperative tissue sampling, or implant sonication. Results: A total of 32 cases of IPOS with a mean patient age of 68.7 years (37.6 to 84.1) were included. Diabetes, age > 60 years, and history of infection were identified as risk factors. Patient presentation upon admission included a mean body temperature of 36.7°C (36.1 to 38.0), back pain at rest (mean visual analogue scale (VAS) mean 5/10) and when mobile (mean VAS 6/10), as well as elevated levels of CRP (mean 76.8 mg/l (0.4 to 202.9)) and white blood cell count (mean 9.2 units/nl (2.6 to 32.8)). Pathogens were identified by CT-guided or conventional biopsy, intraoperative tissue sampling, or sonication, and Gram-positive cocci presented as the most common among them. Antibiotic therapy was established in all cases with pathogen-specific treatment in 23 (71.9%) subjects. Overall 27 (84.4%) patients received treatment by debridement, decompression, and fusion of the affected segment. Conclusion: Cases of IPOS are rare and share similarities with spontaneous spondylodiscitis. While procedures such as CT-guided biopsy and sonication are valuable tools in the diagnosis of IPOS, MRI and intraoperative tissue sampling remain the gold standard. Research on known principles of PJI such as implant retention versus implant exchange need to be expanded to the field of spine surgery.

Adverse Events Associated with Prolonged Antibiotic Therapy for Periprosthetic Joint Infections-A Prospective Study with a Special Focus on Rifampin.

Periprosthetic Joint Infection (PJI) is a significant contributor to patient morbidity and mortality, and it can be addressed through a range of surgical interventions coupled with antibiotic therapies. Following surgical intervention(s), prolonged administration of oral antibiotics is recommended to cure PJI. There is a lack of reports on the adverse events (AEs) associated with oral antibiotics, particularly rifampin. This investigation sought to elucidate the occurrence of antibiotic-related AEs after an initial regimen of intravenous antibiotic administration, supplemented by an extended course of oral antibiotics. A prospective study of patients diagnosed with PJI of the hip, knee, or shoulder who underwent single-stage exchange arthroplasty (SSE) (10%), two-stage exchange arthroplasty (TSE) (81%), or debridement, antibiotics, and implant retention (DAIR) (6%) was performed. The primary outcome of interest was the detection of AEs, the secondary outcome the detection of a correlation between rifampin use and the incidence of AEs, and the tertiary outcome was whether oral antibiotic treatment needed to be adjusted or discontinued due to AEs. In addition, subjective tolerability was monitored throughout the study. A total of 336 events were identified for 73 out of 80 patients. The most frequently used antibiotics were rifampin and co-trimoxazole. Most AEs occurred in the gastrointestinal tract (46%). The most frequent AEs were nausea, inappetence, diarrhea, and skin rash. In 6% of cases, the AEs led to antibiotic discontinuation, and in 29% of cases, a dose adjustment of the oral therapy occurred, mainly with amoxicillin or co-trimoxazole. The majority of patients (55%) rated the subjective tolerability as good. In conclusion, AEs during antibiotic treatment for PJI are common. They mainly affect the gastrointestinal tract. Rifampin use might be a reason for the higher incidence of AEs compared to non-rifampin antibiotic treatment.

Increased ankle pain after total knee arthroplasty is associated with a preoperative lateralized gait and talar tilt, but not with ankle laxity or the range of motion of the subtalar joint.

Aims: Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods: Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results: A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion: Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait.

Psychological status affects postoperative quality of life, function, and pain after periacetabular osteotomy.

Aims: Psychological status may be an important predictor of outcome after periacetabular osteotomy (PAO). The aim of this study was to investigate the influence of psychological distress on postoperative health-related quality of life, joint function, self-assessed pain, and sports ability in patients undergoing PAO. Methods: In all, 202 consecutive patients who underwent PAO for developmental dysplasia of the hip (DDH) at our institution from 2015 to 2017 were included and followed up at 63 months (SD 10) postoperatively. Of these, 101 with complete data sets entered final analysis. Patients were assessed by questionnaire. Psychological status was measured by Brief Symptom Inventory (BSI-18), health-related quality of life was raised with 36-Item Short Form Survey (SF-36), hip functionality was measured by the short version 0f the International Hip Outcome Tool (iHOT-12), Subjective Hip Value (SHV), and Hip Disability and Outcome Score (HOS). Surgery satisfaction and pain were assessed. Dependent variables (endpoints) were postoperative quality of life (SF-36, HOS quality of life (QoL)), joint function (iHOT-12, SHV, HOS), patient satisfaction, and pain. Psychological distress was assessed by the Global Severity Index (GSI), somatization (BSI Soma), depression (BSI Depr), and anxiety (BSI Anx). Influence of psychological status was assessed by means of univariate and multiple multivariate regression analysis. Results: In multiple multivariate regression, postoperative GSI, BSI Soma, and BSI Depr had a negative effect on postoperative SF-36 (e -2.07, -3.05, and -2.67, respectively; p < 0.001), iHOT-12 (e -1.35 and -4.65, respectively; p < 0.001), SHV (e -1.20 and -2.71, respectively; p < 0.001), HOS QoL (e -2.09 and -4.79, respectively; p < 0.001), HOS Function (e -1.00 and -3.94, respectively; p < 0.001), and HOS Sport (e -1.44 and -5.29, respectively; p < 0.001), and had an effect on postoperative pain (e 0.13 and 0.37, respectively; p < 0.001). Conclusion: Psychological distress, depression, and somatization disorders affect health-related quality of life, perceived joint function, and sports ability. Pain perception is significantly increased by somatization. However, patient satisfaction with surgery is not affected.