Search Results (295)

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

Approximately 15% of total knee arthroplasty (TKA) patients remain dissatisfied after surgery, with joint line obliquity (JLO) potentially affecting patient outcomes. This study investigated whether JLO restoration influenced lower extremity frontal plane joint moments during stair negotiation by TKA patients. Thirty unrestored and twenty-two restored JLO patients participated in this study and were asked to perform five trials on each limb for stair negotiation while three-dimensional kinematics and ground reaction forces were recorded. Frontal plane moments at the ankle, knee and hip were calculated using Visual 3D. The restoration of JLO did not alter frontal plane joint moments during stair negotiation. Both groups showed symmetrical moment profiles, indicating no significant biomechanical differences between the restored and unrestored JLO groups. Restoring JLO did not affect frontal plane joint moments during stair negotiation, suggesting it may not contribute to patient satisfaction disparities post-TKA. Further research should explore other factors, such as surgical technique and implant design, that might influence recovery. 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

Whole-leg radiographs (WLRs) are widely used to assess coronal alignment before total knee arthroplasty (TKA), but may be inaccurate in patients with atypical morphotypes or malrotation. This study evaluated the discrepancy between WLR and 3D computed tomography (CT) scans across coronal plane alignment of the knee (CPAK) morphotypes and introduced a novel projection index—the femoral notch projection ratio (FNPR). In CPAK III knees, 19% of cases exceeded a clinically relevant threshold (>3° difference), prompting investigation of underlying projection factors. In 187 knees, coronal angles—including the medial distal femoral angle (MDFA°), medial proximal tibial angle (MPTA°), femoral mechanical angle (FMA°), and arithmetic hip–knee–ankle angle (aHKA°)—were measured using WLR and CT. Rotational positioning on WLR was assessed using FNPR and the patellar projection ratio (PPR). CPAK classification was applied. WLR systematically underestimated alignment, with the greatest bias in CPAK III (MDFA° + 1.5° ± 2.0°, p < 0.001). FNPR was significantly higher in CPAK III and VI (+1.9° vs. −0.3°, p < 0.001), indicating a tendency toward internally rotated limb positioning during imaging. The PPR–FNPR mismatch peaked in CPAK III (4.1°, p < 0.001), suggesting patellar-based centering may mask rotational malprojection. Projection artifacts from anterior osteophytes contributed to outlier measurements but were correctable. Valgus morphotypes with oblique joint lines (CPAK III) were especially prone to projection error. FNPR more accurately reflected rotational malposition than PPR in morphotypes prone to patellar subluxation. A 3D method (e.g., CT) or repeated imaging may be considered in CPAK III to improve surgical planning. 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/Objectives: Aseptic loosening is a major challenge in hip and knee arthroplasty. While radiostereometric analysis (RSA) is the gold standard for detecting early migration, it is static, costly, and requires metal beads. Provocation CT-based analysis studies implants under physiological stresses and offers a marker-free alternative with comparable accuracy. This systematic review evaluates its effectiveness, cost, and role in orthopedic imaging. Methods: A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Three databases were searched, with no date restrictions, using keywords related to the research area. The risk of bias was assessed using the RoB-1 tool. Results: The initial search identified 42 studies, with 6 ultimately included in the review. These studies involved 198 patients with an average age of 65.0 years. Provocation CT demonstrated higher sensitivity and specificity than standard radiographs, particularly in cases with inconclusive X-rays. Additionally, the radiation dose for CT scans varied across studies, with effective doses ranging from 0.2 mSv to 4.5 mSv per scan. Compared to X-ray, CT-based methods showed comparable or superior performance in motion detection, though direct clinical comparisons with RSA remain lacking. Conclusions: Provocation CT-based analysis is a valuable diagnostic tool for early detection of implant loosening, offering a potentially feasible, accurate, and cost-effective alternative to traditional methods. However, standardized protocols, broader economic evaluations, and prospective multicenter trials are needed to confirm its routine clinical applicability. Full article

Background: Osteoarthritis (OA) of the hip and knee is a common age-related degenerative disease characterized by joint pain, stiffness, and gait disturbances. This study investigated the influence of genetic polymorphisms in the OPRM1 (rs1799971) and COMT (rs4633, rs4680, rs4818, and rs6269) genes on the postoperative analgesic requirements in 195 diabetic and non-diabetic patients undergoing total hip or knee arthroplasty. Methods: The prospective study included all patients who were admitted between January and September 2020 and agreed to participate. Postoperative pain management was assessed based on acetaminophen, ketoprofen, and morphine consumption on the first and second postoperative day. Results: Multilevel regression analyses revealed a significant three-way interaction between diabetes, type of analgesic, and OPRM1rs1799971 polymorphism, indicating different analgesic dosing patterns in diabetic and non-diabetic patients. Two-way interactions between diabetes and COMT polymorphisms rs4633, rs4680, and rs6269 further influenced the analgesic requirements. No significant associations were found for COMT rs4818. The results show that diabetes and genetic factors significantly influence opioid requirements and pain perception. Conclusions: Given the complexity of pain management in diabetic patients, personalized analgesic strategies tailored to genetic and metabolic profiles could be useful in postoperative pain management and reducing opioid consumption. Full article

Periprosthetic joint infection (PJI) is a complex complication of total joint arthroplasty, with microbiological profiles varying across centers worldwide. However, most studies are limited to single-center or intra-country multicenter analyses, often including mixed cohorts of primary and revision PJI cases, with limited data regarding global antibiotic resistance patterns. This study compared the microbiological characteristics, polymicrobial culture rates, prevalence of culture-negative infections, and antibiotic resistance patterns in PJI cases across five referral centers from five continents. A total of 717 patients with primary hip and knee PJI were included from centers in Argentina, Canada, Turkey, England, and New Zealand. Staphylococcus aureus and Staphylococcus epidermidis were the most common pathogens (48.5%, p < 0.01). Culture-negative infection rates varied significantly, ranging from 4.2% (England) to 24.6% (Turkey) (p < 0.01). Polymicrobial infections were the most frequent in Canada (8.9%) and the least frequent in England (1.1%) (p < 0.01). Gram-negative bacteria comprised 13.1% of culture-positive cases, with no significant intercountry difference. Multidrug resistance was observed in all centers, ranging from 23.7% (Argentina) to 43.1% (Turkey), with no statistical significance. Vancomycin resistance was detected in England (2.3%) and Canada (1.2%) but absent in Turkey, New Zealand, and Argentina. These findings underscore significant intercontinental variability, emphasizing the need for regional considerations in regards to empiric antibiotic selection and PJI management. Full article

Background/Objectives: Alkaptonuria (AKU) is a rare genetic disorder characterized by elevated levels of circulating homogentisic acid (HGA), which accumulates in connective tissues. The musculoskeletal system is particularly susceptible to HGA deposition, often resulting in severe ochronotic osteoarthropathy, especially in the hips, shoulders, knees, and spine. However, little is known about the effects of AKU on skeletal muscle tissue. The study aimed to evaluate changes in lower limb muscles associated with AKU. Methods: This case report describes the treatment of ochronotic osteoarthropathy in the knee of a 73-year-old male patient. Muscle properties were assessed using the MyotonPRO device. The rectus femoris, vastus medialis, and patellar tendon were examined both preoperatively and three months postoperatively. Results: Following total knee arthroplasty (TKA) of the right knee, the patient demonstrated significant improvement in functional outcomes. The MyotonPRO assessment revealed measurable differences in muscle properties between the operated and non-operated limbs. Postoperative measurements indicated improvements in muscle tone, elasticity, and viscoelastic parameters in the treated limb. Conclusions: This case report supports the effectiveness of TKA as a treatment for ochronotic osteoarthropathy. Furthermore, it is the first study to use the MyotonPRO to assess muscle and tendon properties in a patient with AKU. These findings highlight the need for further research into the muscular effects of this rare metabolic disorder. Full article

Background/Objectives: Periprosthetic joint infection (PJI) is a severe complication that follows arthroplasty and occurs in approximately 2% of all cases. One of several cornerstones of therapy is an optimized antibiotic regimen. Early administration of rifampicin—together with a combination of an antibiotic to which the specific microorganism is susceptible—accompanying a two-stage revision surgery, remained controversial due to the potential risk of emerging resistance. However, the exact time to start rifampicin treatment often remains unclear and might be crucial in the treatment regimen. Methods: In a retrospective study design, a total of 212 patients receiving a two-stage revision surgery after a diagnosis of PJI (60.8% THA, 39.2% TKA) received an individual rifampicin combination therapy after initial debridement and removal of all foreign material, starting rifampicin on the second day postoperatively. Results: At the time of spacer explantation, two patients had developed rifampicin resistance (0.9%). At follow-up (M = 55.4 ± 21.8 months) after reimplantation, three patients had developed rifampicin resistance (1.4%). Concerning the development of reinfection, in general, in the study group and the necessity for further treatment, a total of 25 patients showed signs of reinfection (11.8%). Conclusions: Only 0.9% after the first stage and 1.4% at follow-up after the second stage of all 212 patients with accompanying long-term rifampicin combination therapy developed a rifampicin resistance. Therefore, rifampicin administration could be started on the second postoperative day when sufficient concentrations of the accompanying antibiotics can be expected. Full article

Background: Balance and gait are critical for functional recovery and fall prevention following total hip (THA) and knee arthroplasty (TKA). Despite improvements in pain and joint function, residual impairments often persist. The Timed Up and Go (TUG) test and Tinetti Performance-Oriented Mobility Assessment (POMA) objectively measure postoperative mobility and balance, while patient-reported outcome measures (PROMs) assess perceived function and well-being. This study longitudinally evaluates functional measurement and PROMs to explore their interrelationships and compare recovery trajectories in THA and TKA cohorts. Methods: In this prospective study, 22 THA and 21 TKA patients were assessed preoperatively and at 4–6 days, 6 weeks, 3 months, and 12 months postoperatively using TUG, Tinetti, Hip Disability and Osteoarthritis Outcome Score (HOOS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and clinical scores (Harris Hip Score (HHS) for THA, Knee Society Score (KSS) for TKA). Pearson correlation assessed relationships between measures. Results: Both cohorts demonstrated significant immediate postoperative declines in balance and mobility, recovering to baseline by 6 weeks and surpassing it by 3 and 12 months (p < 0.001). PROMs showed earlier and sustained improvements. Objective balance and mobility measures showed minimal correlation with PROMs but were highly interrelated from 6 weeks onward. Conclusions: THA and TKA patients experience early postoperative balance impairments, suggesting heightened fall risk, with functional recovery lagging behind perceived well-being, highlighting the need for cautious rehabilitation strategies. Full article

Purpose: The purpose of this scoping review was to systematically identify and summarize the existing literature on non-spinal clinical applications of EOS imaging and identify related evidence gaps. Method: The study followed the PRISMA-ScR guidelines. A systematic literature search was conducted in Embase, MEDLINE, CINAHL, Scopus, Cochrane, Academic Search Premier, and OpenGrey databases in November 2022 and updated in December 2023. Original research from 2003 to 2023 was eligible if in English, Danish, French, German, Norwegian, or Swedish. Two authors screened articles by title and abstract, while data extraction from full texts was performed by seven authors using a structured template. Results: A total of 8176 articles were identified, with 1350 selected for full-text review and 268 included in data extraction. Among adults, 187 articles were included, with 88 focused on surgical applications like hip arthroplasty or osteotomy. In pediatrics, 68 general and 13 surgery-related articles were included. Lower extremity analysis was the most frequent topic, with other uses identified, such as rib cage geometry, patellar dislocation, and X-linked hypophosphatemia. Conclusions: Key clinical applications of EOS imaging include lower extremity analysis, e.g., leg length assessment and knee/hip arthroplasty planning), pelvic and spinal alignment studies, and emerging uses in rib cage geometry. Evidence gaps include limited research on the diagnostic accuracy of EOS for cerebral shunt placement, reliability in bone age estimation, and an unclear role in foot and ankle morphology. Full article

Background: Accurate partial weight-bearing (PWB) is essential for postoperative recovery after lower limb surgery, yet patients often fail to maintain load within clinically meaningful thresholds. Methods: In this pilot randomised controlled trial with 1:1 concealed allocation, 34 inpatients aged 18–85 who underwent femoral fracture fixation, hip arthroplasty, or knee arthroplasty were enrolled and followed for 14 days. Participants were randomly assigned to either standard physiotherapy or the same protocol with a low-cost tactile insole (“incentiviser”) that provides mechanical feedback when the prescribed 20% body weight (BW) load is exceeded. The primary outcome was absolute deviation from target load, with a minimal clinically important difference (MCID) of ±2 kg. Results: In total, 88% of the intervention group achieved the MCID at discharge versus 24% of controls. The between-group difference in final load error was 10.8 kg (95% CI: −15.2 to −6.4), with a large effect size (Cohen’s d = 1.71). No significant differences were found in pain (NRS) or walking distance (6MWT) between groups. Conclusions: The tactile incentiviser significantly improved PWB accuracy within 14 days, meeting MCID thresholds in most cases. Its low cost and simplicity make it promising for routine or home-based use. Limitations include the small sample, diagnosis heterogeneity, and absence of a sham control. Larger multicentre trials are needed to confirm generalisability and long-term clinical impact. Full article

Background: Periprosthetic joint infections (PJIs) remain a major challenge in arthroplasty. This study tries to evaluate the PJI-TNM classification as predictor for the revision-free implant survival in patients with PJI of the hip or knee joint. Methods: To this end, we perform a retrospective study of all consecutive patients with PJI of an inlying hip or knee arthroplasty between January 2015 and December 2019. Results: A total of 443 cases (hip: n = 247; knee n = 196) were identified. In total, 439 patients underwent surgery (DAIR: n = 138 cases (31%), explantation: n = 272 (61%), irrigation with debridement without exchange of implant components: n = 29 (6.5%)). Four patients refused surgical treatment and 39.5% were lost to follow-up. In total, 78 patients died during follow-up and 27 deaths were directly related to PJI/complications during treatment. Patients with inlying “standard”-implants (p < 0.001) and without previous history of PJI (p = 0.002) displayed a significantly higher postoperative revision-free implant survival. In terms of the PJI-TNM subclassification, patients with loosened implants but without soft-tissue defects (T1) displayed the highest revision-free implant survival. In contrast, patients classified as M3 (no surgical treatment possible) displayed an inferior outcome compared to M0, M1, or M2. Patients with different N-subclassifications (“non-human cells”/causative pathogen) did not display differences in revision-free implant survival. Conclusions: The PJI-TNM classification is well suited to classify PJIs. Its complexity allows for more than 500 different combinations of classifications. Further validation data are needed, but to us, the PJI-TNM classification seems to offer the possibility of comparing patients with PJIs. It may, therefore, be a very valuable tool in order to compare cohorts with PJIs and provide individual data for patient specific outcomes. Full article