Search Results (268)

Periprosthetic joint infection (PJI) caused by Streptococcus bovis (S. bovis) is rare but clinically significant due to its established association with colorectal neoplasia. Early recognition and interdisciplinary management are essential to ensure favorable outcomes. We report the case of a 68-year-old woman who presented with a chronic fistula and signs of active infection 20 years after uncemented total hip arthroplasty. Cultures from the wound identified S. bovis, prompting further evaluation. Imaging and laboratory tests supported a diagnosis of chronic PJI. A two-stage revision was performed, beginning with implant removal, debridement, and placement of a vancomycin/gentamicin-loaded spacer. Given the pathogen’s known link to gastrointestinal malignancy, the patient underwent colonoscopy, which revealed a tubulovillous adenoma with carcinoma in situ. Surgical resection was performed with curative intent. Six months later, the patient underwent successful reimplantation. At three-month follow-up, clinical and radiographic assessments showed favorable recovery. This case reinforces the importance of gastrointestinal screening in patients with S. bovis PJI, as early detection of associated colorectal lesions may impact treatment strategies and prognosis. Full article

Background: Periprosthetic joint infection (PJI) is one of the most serious complications following total joint arthroplasty. The debridement, antibiotics, irrigation, and implant retention (DAIR) procedure is commonly employed to treat acute, early-stage infections, but its success is highly variable, influenced by factors such as pathogen virulence and antibiotic susceptibility profiles. This study aimed to evaluate the impact of pathogens responsible for these infections on the outcome of DAIR. Methods: This retrospective, single-center study analyzed the microbiological profiles of 116 patients (66 hips and 50 knees) treated for acute periprosthetic joint infections (PJIs) with DAIR between 2018 and 2022. Acute PJI was defined as a duration of symptom less than three weeks, according to the criteria established by the Tsukayama and Izakovicova classification. Preoperative joint aspirations, intraoperatively collected tissue samples, and sonication of the exchanged mobile parts were analyzed for each case. We differentiated between monomicrobial PJI, polymicrobial PJI (defined as the identification of more than one microorganism from preoperative joint fluid aspiration or intraoperative samples), and difficult-to-treat (DTT) pathogens. Results: In this cohort, the following pathogen profiles were identified: culture-negative cases accounted for 11.1% of infections, while 64.2% were attributed to Gram-positive bacteria, 19.8% to Gram-negative bacteria, and 4.9% to fungal pathogens. Among the identified microorganisms, coagulase-negative staphylococci (CNS) were the most frequently detected, exhibiting a notable oxacillin resistance rate of 52.9% and rifampicin resistance rate of 28.7%. Additionally, no significant difference in revision-free implant survival was found between patients with DTT pathogens and/or polymicrobial PJI and those without such infections. Conclusions: This study highlights that pathogens in prosthetic joint infections (PJIs) do not solely determine outcomes, as patient-specific factors (comorbidities, implant type) may also play a key role. Regional variations in pathogens and antibiotic resistance patterns should guide empirical therapy. For instance, this study found a high reliance on vancomycin due to high oxacillin resistance in CNS, the most frequent causative pathogen. Full article

Background: Robotic-assisted unicompartmental knee arthroplasty (UKA) enhances the precision of component alignment compared to conventional techniques. Although various robotic systems exist, direct comparisons assessing their relative clinical performance remain limited. The purpose of this study is to provide a comparison between image-based and imageless robotic UKA. Methods: A systematic review was conducted in accordance with PRISMA guidelines. Five databases were searched: PubMed (via MEDLINE), Epistemonikos, Cochrane Library, Web of Science, and Scopus. Inclusion criteria were (1) studies comparing rUKA and cUKA with radiologic parameters and revision rates (prospective or retrospective), (2) human subjects, (3) meta-analyses for cross-referencing, and (4) English language. Data collected included (1) pre- and postoperative radiologic parameters, (2) radiologic outliers, and (3) revisions and their causes. A random-effects meta-analysis was employed to enable a generalizable comparison. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables, and log odds ratios (LORs) with 95% CIs for binary outcomes. Results: Image-based robotic UKA was associated with fewer joint line height outliers (LOR = 3.5, 95% CI: 0.69–6.30, p = 0.015) using a 2° threshold. HKA outliers (thresholds 2–3°) were also reduced (LOR = 0.6, 95% CI: 0.09–1.19, p = 0.024). Posterior tibial and posterior femoral implant fit were significantly lower with image-based systems (LOR = 1.7, 95% CI: 1.37–2.03, respectively, LOR = 1.7, 95% CI: 1.29–1.91; p < 0.001 for both). No significant differences in revision rates were observed. Conclusions: Image-based robotic systems may result in fewer outliers in key radiologic parameters, including hip–knee angle, joint-line height, posterior tibial, and posterior femoral fit, though reporting remains highly heterogeneous. Full article

Background/Objectives: Tapered, fluted, modular titanium stems (TFTSs) are widely used in complex femoral reconstructions during total hip arthroplasty (THA), but evidence regarding the clinical performance of specific modular implant designs remains limited. This study aimed to compare the early clinical and radiographic outcomes of complex primary and revision THA using the M-Vizion^® modular stem system. Methods: We retrospectively analyzed 109 patients (46 complex primary and 63 revision THA cases) treated with the M-Vizion^® cementless modular TFTSs between 2020 and 2023. Clinical outcomes were assessed using the Hip Disability and Osteoarthritis Outcome Score (HOOS) and the Forgotten Joint Score (FJS) at 1- and 2-years post-surgery. Radiographic evaluation included stem subsidence, radiolucent lines, heterotopic ossification, and complications. Clinically relevant subsidence was defined as >5 mm. Statistical analysis was performed using ANOVA. Results: The mean follow-up was 33.3 months for complex primary and 31.8 months for revision THA. Both groups demonstrated significant improvement in FJS over time (p < 0.05). In the revision group, HOOS improved significantly from baseline to follow-up (p < 0.001). Mean stem subsidence was 2.1 mm in the complex primary group and 1.8 mm in the revision group; nine patients (8.3%) had subsidence greater than 5 mm. No cases of aseptic loosening or stem fracture were observed. The overall complication rate was low, with dislocations (3.2%) and infections (2.8%) requiring revision. Conclusions: The M-Vizion^® TFTS system demonstrated favorable short-term outcomes in both complex primary and revision THA. These findings suggest potential utility in complex femoral reconstruction, although confirmation through longer-term studies is warranted. Full article

Introduction: Instability following total hip arthroplasty (THA) remains a challenging complication. Dual-mobility (DM) hip components are aimed at improving joint stability by increasing the head-neck ratio and jump distance. However, data regarding the efficacy of these implants in the trauma setting are scarce. This study aimed to compare the dislocation rates of DM bearings with conventional THA in patients undergoing primary THA for the treatment of hip fractures. Methods: We retrospectively reviewed all patients who underwent THA for hip fractures between the years 2010–2022 and had a minimum follow-up of two years. Patient demographics and radiographic parameters, including cup version, leg length discrepancy (LLD) and femoral horizontal offset, were compared between patients who received DM bearings and patients who received conventional THA. Dislocation and revision surgery rates were also compared between the groups. Results: The study included 570 patients who met inclusion criteria, of which 82 patients were in the DM bearings group and 488 patients were in the conventional THA group. Baseline demographics and comorbidity profiles were comparable between the groups. Cup anteversion was significantly lower in the DM group (11.1° vs. 14.1°; p = 0.006), while no significant differences were observed in LLD nor femoral offset between the groups (p = 0.38, p = 0.69, respectively). Dislocation rates were similar between the DM and conventional THA groups (1.2% vs. 1.02%, respectively; p = 0.54). Furthermore, revision rates were similar between DM and conventional THA (1.22% vs. 2.87%, respectively; p = 0.387). Conclusions: While no significant differences in dislocation rates were observed between dual-mobility and conventional THA bearings, the significantly lower cup anteversion suggests a potential improvement in acetabular safe zone positioning, this could reflect a broader margin for error in implant positioning. Further prospective studies are needed to elucidate the biomechanical advantages of DM bearings in patients with hip fractures. Full article

Background: Microbial analyses of tissue samples are of paramount importance for diagnostic and therapeutic purposes in the course of septic revision arthroplasty. Isolation and identification of the causative pathogens pave the way for successful treatment of periprosthetic joint infections, which necessitates a reliable microbiological workup. It is unknown if there are inconsistencies in pathogen detection and differentiation between accredited laboratories in the context of septic revision arthroplasty. Methods: Tissue samples of forty consecutive patients undergoing septic total hip and knee revision surgery were sent to two different accredited and certified laboratories and tested for pathogen growth and bacterial differentiation. Results: Each institution analyzed 200 specimens. Twenty-five patients (62.5%) showed consistent results between laboratories. Diverging results were observed in 15 of 40 patients (37.5%). Of these, three individuals showed pathogen growth in only one laboratory. In 12 patients with discrepant results, laboratory analyses revealed a partly different pathogen spectrum. With regard to clinical impact and infection eradication, the respective differences implicated a therapeutic response by a change of the administered postoperative antibiotic treatment in five (12.5%) of the patients. The kappa correlation coefficient indicated a slight value in terms of data consistency between institutions (k = 0.227, p = 0.151). Conclusions: The majority of evaluated samples show comparable results with regard to microbiological evaluation. Nevertheless, a substantial number of specimens were classified differently. The observed discrepancies pose a challenge for postoperative decision-making. Against this background, standardized microbiological protocols remain mandatory for a conclusive clinical implication to eradicate PJI. Full article

Background: Implantation of modularly built-up stems with a tapered and fluted design is currently state of the art in revision total hip arthroplasty (RTHA). Nevertheless, implant-specific major complications like breakage of taper junctions as well as periprosthetic fractures (PPFs) may lead to failure of reconstruction during follow-up. Methods: A cohort of 117 cases receiving femoral RTHA by a modular stem was investigated retrospectively with a mean follow-up of 5.7 (0.5–13.7) years. Cumulative risk and potential factors affecting the occurrence of PPFs were calculated with the Kaplan–Meier method. In addition, cases were presented to discuss operative treatment options. Results: A cumulative risk of PPF of 12.1% (95% CI: 0–24.6%) was calculated at 13.7 years. Female patients had significantly higher risk compared to male patients (0% after 13.5 years for male patients vs. 20.8% (95% CI: 0.5–41.2%) after 13.7 years for female patients; log-rank p = 0.0438) as all five patients sustaining a PPF during follow-up were women. Four fractures were treated by open reduction and internal fixation. Non-union and collapse of the fracture occurred in one patient after closed reduction and internal fixation. Conclusions: Postoperative PPF after femoral revision with a modular stem has shown to be a frequent complication within this mid-term follow-up. Female patients were at a significantly higher risk in this aged cohort, indicating osteoporosis as a risk factor. The surgical treatment of PPF with an integrated long-stemmed prosthesis is challenging and thorough considerations of adequate operative treatment of PPFs are strongly advised in order to limit complication rates. Full article

Background/Objectives: Spacer dislocation is among the most frequent mechanical complications after revision total hip arthroplasty for periprosthetic hip infection. Spacer dislocations may be managed conservatively, but there are no guidelines on the rehabilitation of these patients, and the restriction of weight bearing is still under debate. Methods: We first report the case of a patient with hip spacer cranial dislocation, judged unfit to be surgically treated once more for a medium period, who started a rehabilitation program with partial weight bearing. Results: After two weeks of inpatient rehabilitation, the patient started to maintain the standing position with partial weight bearing on the affected side. Following hospital discharge we continued rehabilitation in the outpatient clinic. Despite the finding of the denervation of the ipsilateral quadriceps, three months after admission, she was able to walk for short distances using a walker, initially with the help of a therapist and then with supervision. About one year later, she was able to undergo the reimplantation of the definitive prosthesis. Conclusions: Despite the spacer dislocation, walking short distances is a feasible goal, even with assistance, wearing a brace and using a walker. Future research is needed to confirm and expand upon this observation and to understand the mechanisms underlying the development of neurological complications to implement effective prevention strategies. Full article

Background: Periprosthetic joint infections (PJIs) are considered as one of the most serious complications after total joint arthroplasty. Aim of this study was to evaluate the prevalence of PJI caused by difficult-to-treat (DTT) pathogens as well as PJIs with a superinfection with a DTT pathogen in the course of the infection and assess the risk factors leading to this emergence. Methods: Data of 169 consecutive patients with a PJI was analyzed in this retrospective observational single-center study, and cases were categorized into PJIs with initial DTT pathogens, PJIs with DTT pathogen superinfection, non-DTT PJIs, and PJIs with superinfection. Recorded parameters comprised age, gender, side, body mass index (BMI), preoperative anticoagulation, and serum level of C-reactive protein (CRP) at admission, as well as preoperative patient status using the ASA (American Society of Anesthesiologists) score and the age-adjusted form of the Charlson comorbidity index (CCI). Furthermore, the infecting microorganism and the type of infection as well as the chosen operative treatment regime, duration of the antibiotics interval, and the outcome were recorded. Results: In total, 46.2% of cases were DTT PJIs, and 30.8% of them were superinfections. Elevated serum CRP levels at admission (≥92.1 mg/L) were linked to a nearly 7-fold increased likelihood of a DTT PJI (OR 6.981, CI [1.367–35.63], p = 0.001), compared to patients with a non-DTT PJI. Hip joint involvement was also associated with a 3.5-fold higher risk compared to knee joints (OR 3.478, CI [0.361–33.538], p = 0.0225). Furthermore, patients undergoing ≥3 revision surgeries demonstrated a significantly 1.3-fold increased risk of developing a DTT superinfection (OR 1.288, CI [1.100–1.508], p < 0.0001). Chronic PJIs were similarly associated with a markedly 3.5-fold higher likelihood of superinfection by DTT pathogens (OR 3.449, CI [1.159–10.262], p = 0.0387). Remaining parameters did not significantly affect the rate of a DTT PJI or a PJI with DTT superinfection. Conclusions: These findings underscore the importance of early identification of high-risk patients and highlight the need for tailored preventive and therapeutic strategies in managing DTT PJIs. Full article

Background/Objectives: The optimal treatment for femoral neck fractures (FNFs) in the elderly remains unclear. Internal fixation, bipolar hip hemiarthroplasty (BH), standard total hip arthroplasty (THA), or dual mobility (DM-THA) cups have been employed, each presenting various advantages and disadvantages. This systematic review and meta-analysis evaluated comparative studies of BH and DM-THA in FNFs among the elderly, aiming to ascertain differences in outcomes, including functional recovery, patient-reported outcome measures, implant survival, complications, and mortality rates. Methods: This meta-analysis followed PRISMA 2020 guidelines with a pre-registered PROSPERO protocol (CRD420251065762). A comprehensive search of electronic databases and grey literature included only comparative studies of BH and DM-THA in patients over 65 years with FNFs. Results: Sixteen studies were eligible, comprising four randomised controlled trials and twelve retrospective comparative studies involving 11,460 patients (10,036 BH; 1424 DM-THA). Patients with DM-THA exhibited a higher postoperative Harris Hip Score (4.55, p < 0.0001), alongside a lower dislocation risk ([OR] 2.77, p < 0.0001), a reduced revision rate ([OR] 2.36, p < 0.0001), and decreased mortality ([OR] 1.94, p < 0.0001). The operative time was somewhat longer in the DM-THA group, by 12.71 min, and blood loss was greater by 121 mL, indicating significant heterogeneity across the studies. Conclusions: DM-THA for FNFs in elderly patients results in improved functional recovery and lower dislocation, reoperation, and mortality risk. However, longer operative times and increased blood loss remain significant considerations. Further, well-designed comparative studies are required to evaluate overall cost-effectiveness and define the optimal age threshold, beyond which the limitations of DM-THA may outweigh its benefits. Full article

Antibiotic-loaded cement spacers play a crucial role in two-stage revision arthroplasty of infected total hip and knee prostheses. There is still controversy regarding whether the elution from antibiotic-loaded cement spacers is greater than the MIC for a prolonged time between stages. Therefore, the aim of the current review was to determine how long spacers elute antibiotics above the MIC for most causative microorganisms, as well as to evaluate what factors influence that elution. Independent of methodological differences and weaknesses of the studies themselves, several study results indicate that after an early peak of antibiotic release from the spacer in the first 1 to 2 days (followed by a gradual decline), a sufficient release above the MIC for most causative bacteria continues for 6 to 12 weeks. Full article

Background: The increasing incidence of revision total hip arthroplasties (rTHAs), particularly due to failure of the acetabular components and severe bone loss, necessitates reliable surgical solutions. Iliac stemmed cups (ISCs) have emerged as effective options for managing complex pelvic defects, including Paprosky type 3A and 3B acetabular defects, severe developmental dysplasia, and selected pelvic discontinuities. This review examines the historical evolution, clinical indications, and outcomes associated with ISCs. Methods: This narrative review analyzed the historical and recent literature concerning various ISC designs. We critically assessed clinical outcomes, complication rates, and implant survival from 13 key studies. Results: ISCs have progressed significantly from initial monobloc designs to contemporary modular configurations, substantially enhancing surgical versatility and biomechanical stability. Clinical outcomes varied with reported complications such as infection, dislocation, mechanical failure, and aseptic loosening ranging from 10% to over 30%. Newer modular implants like the Sansone cup have demonstrated improved outcomes, with complication rates below 10% and five-year survival rates exceeding 95%. Conclusions: ISCs are reliable and versatile implants, particularly suited to address significant pelvic bone deficiencies. Optimal surgical techniques and careful implant selection remain essential to minimize complications and achieve favorable long-term functional outcomes, making these implants valuable tools in complex hip arthroplasty. Full article

Background and Objectives: To characterize the epidemiological profile of patients undergoing revision total hip arthroplasty (THA) using bone allografts from a tissue bank, and to identify clinical and surgical factors associated with the selection of graft type in cases of severe periprosthetic bone loss. Materials and Methods: This observational, cross-sectional study involved a retrospective review of medical records from a specialized referral center, including revision THA procedures performed between 2013 and 2019. Data were collected on 36 variables covering demographic details (age, sex), surgical history of both hips, comorbidities, medication use, perioperative complications, hospitalization, surgical technique, and characteristics of the bone grafts used. Patients were grouped based on the type of allograft received—structured or morselized (impacted)—and comparative analyses were performed. Results: A total of 67 revision THA cases were evaluated, with a mean patient age of 63.2 years. Nearly half (47.8%) had no prior hip revision. The average number of previous procedures per patient was 1.73, and the mean interval from primary THA to revision was 178.4 months. Morselized bone allografts were used in 66.7% of cases, and structured allografts in 33.3%. Patients receiving structured grafts had undergone a significantly higher number of prior surgeries (p = 0.01) and had a longer duration since the initial THA (p = 0.04). Conclusions: These findings suggest that younger patients undergoing primary total hip arthroplasty may be at increased risk for complex revision procedures involving structured grafts later in life, underscoring the need for long-term monitoring and tailored surgical planning in this population. Full article

Periprosthetic femoral fractures (PPFFs) represent the third most frequent indication for revision total hip arthroplasty (THA). Given the steadily increasing number of primary hip replacements, this complication is gaining growing attention among orthopedic surgeons. Clamshell fracture (CF) constitutes a particularly controversial and underrecognized fracture pattern that, for a long time, was not accounted for in the commonly used classification systems for PPFFs. Recent studies suggest that the incidence and clinical relevance of these injury patterns have been underestimated. Therapeutic options are manifold and depend on various patient-specific factors as well as stem stability. Despite this, the current literature remains limited, and standardized therapeutic approaches are still poorly defined. This review aims to provide a comprehensive overview of clamshell fractures as a distinct pattern of periprosthetic injuries. Furthermore, relevant treatment options dependent on biomechanical considerations will be outlined and discussed. Full article

The increasing number of acetabular revision total hip arthroplasties requires the evaluation of alternative materials in addition to established standards using a defined animal experimental defect that replicates the human acetabular revision situation as closely as possible. Defined bone defects in the load-bearing area of the acetabulum were augmented with various materials in an ovine periacetabular defect model (Group 1: NanoBone^® (artificial hydroxyapatite-silicate composite; Artoss GmbH, Germany); Group 2: autologous sheep cancellous bone; Group 3: Tutoplast^® (processed allogeneic sheep cancellous bone; Tutogen Medical GmbH, Germany)) and bridged with an acetabular reinforcement ring of the Ganz type. Eight months after implantation, a μ-CT examination (n = 8 animals per group) was performed. A μ-CT analysis of the contralateral acetabula (n = 8, randomly selected from all three groups) served as the control group. In a defined volume of interest (VOI), bone volume (BV), mineral volume (MV), and bone substitute volume (BSV), as well as the bone surface (BS) relative to the total volume (TV) and the surface-to-volume ratio (BS/BV), were determined. To assess the bony microarchitecture, trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and trabecular number (Tb.N), as well as connectivity density (Conn.D), the degree of anisotropy (DA), and the structure model index (SMI), were evaluated. The highest BV was observed for NanoBone^® (Group 1), which also showed the highest proportion of residual bone substitute material in the defect. This resulted in a significant increase in BV/TV with a significant decrease in BS/BV. The assessment of the microstructure for Groups 2 and 3 compared to Group 1 showed a clear approximation of Tb.Th, Tb.Sp, Tb.N, and Conn.D to the microstructure of the control group. The SMI showed a significant decrease in Group 1. All materials demonstrated their suitability by supporting biological defect reconstruction. NanoBone^® showed the highest rate of new bone formation; however, the microarchitecture indicated more advanced bone remodeling and an approximate restoration of the trabecular structure for both autologous and allogeneic Tutoplast^® cancellous bone when using the impaction bone grafting technique. Full article