Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are considered among the most successful surgical interventions in modern medicine, offering significant pain relief and functional improvement in patients with advanced osteoarthritis, avascular necrosis, and other disabling joint pathologies [1,2]. With increasing life expectancy, changing lifestyles, and higher prevalence of degenerative joint disease, the demand for arthroplasty procedures is rising globally and in India [3]. Despite advances in surgical techniques, implant design, perioperative antibiotic prophylaxis, and operating room protocols, periprosthetic joint infection (PJI) remains one of the most dreaded complications following arthroplasty [4]. PJI is defined as an infection involving the joint prosthesis and adjacent tissues, usually caused by biofilm-forming microorganisms that adhere to implant surfaces, rendering eradication particularly challenging [5]. The 2018 Musculoskeletal Infection Society (MSIS) and International Consensus Meeting (ICM) criteria have standardized the diagnosis of PJI, improving consistency across studies [6]. The reported incidence of PJI after primary arthroplasty ranges from 0.5% to 2% in most large series, while revision arthroplasty carries a higher risk, ranging between 5% and 10% [7,8]. Staphylococcus aureus and coagulase-negative staphylococci are the predominant organisms, although Gram-negative bacilli and culture-negative infections are increasingly reported [9]. Regional variations exist, with some studies from developing countries reporting slightly higher infection rates due to differences in perioperative care, patient comorbidities, and infection control practices [10]. The clinical and economic consequences of PJI are substantial. It is one of the leading causes of revision surgery worldwide [11], and is associated with prolonged hospitalization, repeated surgical interventions, impaired mobility, psychosocial stress, and even increased mortality [12,13]. The management of PJI involves a combination of surgical strategies-such as debridement, antibiotics, and implant retention (DAIR), single-stage or two-stage revision-and prolonged, targeted antimicrobial therapy, often necessitating multidisciplinary coordination [14,15]. Although global data on PJI epidemiology and outcomes are robust, literature from India remains limited, with most reports being retrospective and single-center. Prospective surveillance studies from tertiary care centers are essential to generate reliable epidemiological data, understand microbial patterns in our setting, and evaluate outcomes of management strategies. Such information will not only help in benchmarking against international standards but also aid in tailoring infection prevention and treatment protocols to local needs [16]. This prospective study was therefore conducted to assess the incidence, causative organisms, and management outcomes of PJI in patients undergoing hip and knee arthroplasty at a tertiary care teaching hospital in Hapur, India.

This was a prospective observational study conducted in the Department of Orthopaedics, Saraswathi Institute of Medical Sciences, Hapur, over a period of one year, from May 2024 to April 2025. All patients undergoing primary or revision total hip and knee arthroplasty during the study period were included. Patients were followed prospectively from the time of surgery through the postoperative period and at regular follow-ups to monitor for the development of periprosthetic joint infection (PJI). The diagnosis of PJI was made according to the 2018 Musculoskeletal Infection Society (MSIS) criteria, which combine clinical findings, laboratory parameters, microbiological evidence, and intraoperative assessment. Patients with superficial wound infections not involving the prosthesis and those who were lost to follow-up before six months were excluded from the study. For all arthroplasty cases, demographic data, comorbidities, and perioperative details were documented. Postoperatively, patients were monitored clinically and with laboratory tests including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at two weeks, six weeks, three months, and six months. In patients with suspected infection, joint aspiration was performed to analyze synovial fluid for total leukocyte count, differential count, and microbiological culture. Intraoperative tissue samples were also collected in cases requiring revision or debridement. The management of PJI was individualized based on the time of infection onset, implant stability, soft tissue condition, and microbiological profile. Patients with early infection (<3 months postoperatively) were considered for debridement, antibiotics, and implant retention (DAIR) with modular component exchange. Chronic infections (>3 months) were evaluated for either single-stage or two-stage revision arthroplasty, depending on host factors and culture results. Antibiotic regimens were chosen in consultation with the microbiology department and were adjusted according to culture and sensitivity reports. The primary outcome measure was the incidence of PJI, calculated as the number of confirmed infections per total number of arthroplasties performed. The secondary outcome measure was infection eradication, defined as the absence of clinical and laboratory evidence of infection at six months after the completion of treatment. Data were analyzed descriptively, and results were expressed as numbers and percentages.

During the study period of one year, a total of 102 arthroplasties were performed, including 42 total hip arthroplasties (THA) and 60 total knee arthroplasties (TKA). The overall incidence of periprosthetic joint infection (PJI) was 1.96% (2/102 cases). The incidence among hip arthroplasties was 2.38%, while that among knee arthroplasties was 1.67%. Table 1. Distribution of Arthroplasties and Incidence of PJI Procedure Total Performed PJI Cases Incidence (%) Hip Arthroplasty (THA) 42 1 2.38 Knee Arthroplasty (TKA) 60 1 1.67 Total 102 2 1.96 Among the patients who developed PJI, the mean age was 63.5 years, and 50% were male. The most common comorbidities observed among infected patients were diabetes mellitus (50%) and obesity (50%). Both infections occurred in the early postoperative period (<3 months). Table 2. Baseline Characteristics of Patients with PJI (Aggregate Data) Parameter Finding Mean age of infected patients (years) 63.5 Sex distribution (Male: Female) 50%: 50% Common comorbidities Diabetes mellitus 50%, Obesity 50% Timing of infection 100% within 3 months Microbiological analysis showed that 50% of infections were due to Staphylococcus aureus, while the remaining 50% were culture-negative. Table 3. Microbiological Profile of PJI Organism Isolated Percentage of PJI cases Staphylococcus aureus 50% Culture-negative 50% In terms of surgical management, 50% of patients were treated with debridement, antibiotics, and implant retention (DAIR), while 50% underwent two-stage revision arthroplasty. Both patients received prolonged antibiotic therapy tailored to culture results and achieved infection eradication. The overall infection control rate at 6 months was 100%. Table 4. Management Strategies and Outcomes Surgical Strategy Proportion of PJI cases Outcome at 6 months DAIR with modular exchange 50% 100% success Two-stage revision 50% 100% success Overall 100% 100% eradication

This prospective study found a 1.96% incidence of periprosthetic joint infection (PJI) following hip and knee arthroplasty over a one-year period, which is within the internationally reported range of 0.5%-2% for primary arthroplasty [1,2]. Although the absolute number of infections was small, the impact of PJI remains disproportionately high given its association with repeated surgical interventions, prolonged antibiotic therapy, functional impairment, and increased economic burden. Our results showed a slightly higher incidence of infection in hip arthroplasty (2.38%) compared to knee arthroplasty (1.67%). Previous registry-based studies have reported variable results; some suggest higher rates in hips due to larger surgical exposure and greater soft-tissue dissection, while others report higher rates in knees because of implant surface area and wound complications [3,4]. Differences in perioperative care, patient comorbidity profiles, and institutional infection control practices may explain these variations. Both infections in our series occurred in the early postoperative period (<3 months). This is consistent with literature, where early PJIs are often linked to perioperative contamination, wound healing problems, or hematoma formation [5]. Preventive strategies such as optimized perioperative antibiotic prophylaxis, careful soft-tissue handling, and strict operating room asepsis are therefore critical in the first few weeks following surgery. The microbiological profile in our study identified Staphylococcus aureus in one case, while the other was culture-negative. Staphylococci, especially S. aureus and coagulase-negative staphylococci, remain the predominant pathogens worldwide, accounting for over half of all PJIs [6,7]. Their ability to form biofilms on prosthetic surfaces makes eradication particularly challenging. The presence of a culture-negative infection in our cohort (50% of cases) highlights an important diagnostic challenge. Culture-negative PJIs, which account for 7-15% of cases globally [8], may result from prior antibiotic exposure, low-virulence organisms, or inadequate culture techniques. Such cases complicate treatment decisions, often requiring empiric broad-spectrum antibiotics or revision strategies. Recent advances in molecular diagnostics, such as polymerase chain reaction (PCR)-based assays and next-generation sequencing, are promising tools to improve pathogen detection in these difficult cases [9]. In terms of management, our study demonstrated favorable outcomes with both DAIR (debridement, antibiotics, and implant retention) and two-stage revision arthroplasty. DAIR was successful in the patient with an acute, organism-confirmed infection. This supports previous studies that report success rates of 60-80% when DAIR is performed early in the postoperative period with appropriate exchange of modular components [10,11]. Two-stage revision, traditionally considered the gold standard for chronic or complex infections, also resulted in infection eradication in our study, consistent with success rates exceeding 85-90% reported in international series [12]. These results reinforce the importance of individualized treatment planning based on infection timing, implant stability, microbial sensitivity, and host factors. Importantly, our study demonstrated a 100% eradication rate at six months, though the small sample size and relatively short follow-up are limitations. Late hematogenous PJIs, which may occur years after the index procedure, were beyond the scope of this study [13]. Furthermore, while our prospective design and use of standardized diagnostic criteria (2018 MSIS) strengthen the reliability of our findings, the single-center nature and small number of infections limit generalizability. Nonetheless, this study provides much-needed prospective data from India, where most existing literature on PJI is retrospective and limited in scope. The results emphasize that even in resource-limited settings, adherence to strict infection control protocols, timely diagnosis, and multidisciplinary management can achieve outcomes comparable to international standards. Future directions should include multicenter collaborative registries, standardized reporting of PJI cases, and research into cost-effective diagnostic and therapeutic strategies suitable for low- and middle-income countries. In summary, our findings reaffirm that while PJI is relatively uncommon, it remains a devastating complication. Early detection, precise microbiological diagnosis, and tailored surgical-antibiotic strategies are essential for improving patient outcomes. At the same time, prevention through optimization of patient comorbidities, meticulous surgical technique, and robust infection control remains the most effective strategy for reducing the burden of PJI.

This prospective observational study demonstrated a 1.96% incidence of periprosthetic joint infection (PJI) following hip and knee arthroplasty over a one-year period, which is consistent with rates reported worldwide. Although infrequent, PJI remains one of the most devastating complications of arthroplasty, with major implications for patients and healthcare systems. Our findings reaffirm that early diagnosis, organism-directed antimicrobial therapy, and tailored surgical strategies such as DAIR for acute infections and staged revision for complex or culture-negative cases can achieve excellent short-term outcomes. The success of both management strategies in our cohort underscores the importance of timely decision-making, multidisciplinary collaboration, and strict adherence to standardized diagnostic criteria. From a clinical perspective, these results highlight the need for: • rigorous infection prevention protocols in the perioperative setting, • systematic postoperative surveillance during the vulnerable early period, • and the use of individualized treatment pathways based on infection timing, implant stability, and microbial profile. The strengths of this study lie in its prospective design and application of standardized diagnostic criteria. However, the small sample size, single-center scope, and limited follow-up duration remain important limitations. Future research should focus on larger multicenter prospective studies and national registries to provide robust epidemiological data in India. There is also a need for improved diagnostic modalities to address the challenge of culture-negative infections and for comparative studies evaluating the long-term outcomes and cost-effectiveness of different surgical strategies in resource-constrained settings. In conclusion, while the burden of PJI in our institution was relatively low, its consequences justify continuous vigilance. The key to reducing its impact lies in a multifaceted approach that integrates prevention, early recognition, accurate diagnosis, and individualized management-strategies that can collectively improve patient outcomes and optimize healthcare resources.

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