Does arthroscopic or open washout in native knee septic arthritis result in superior post-operative function? A systematic review and meta-analysis of randomised controlled trials and observational studies.

AIMS: Septic arthritis (SA) of the native knee joint is associated with significant morbidity. This review compared post-operative functional outcomes (patient-reported outcome measures (PROMs) and range of movement (ROM)) following arthroscopic washout (AW) and open washout (OW) amongst adult patients with SA of the native knee. The need for further operative intervention was also considered. METHODS: Electronic databases of PubMed, MEDLINE, Embase, Cochrane, Web of Science and Scopus were searched between 16 February 2023 and 18 March 2023. Randomised controlled trials (RCTs) and comparative observational analytic studies comparing function (reflected in PROMs or ROM) at latest follow-up following AW and OW were included. A narrative summary was provided concerning post-operative PROMs. Pooled estimates for mean ROM and re-operation rates were conducted using the random-effects model. The risk of bias was assessed using the Cochrane risk-of-bias assessment tool-2 for RCTs and the Risk of Bias in Non-Randomized Studies of Interventions tool for observational analytic studies. RESULTS: Of 2580 retrieved citations, 7 articles (1 RCT and 6 cohort studies) met the inclusion criteria. Of these, five had some concerns/moderate risk of bias, and two had serious risk. There was a slight tendency for superior mean PROMs following AW compared with OW, but due to small effect sizes, this was unlikely clinically relevant. Additionally, the use of four different PROMs scales made direct comparisons impossible. AW was associated with superior ROM (mean difference 20.18° (95% CI 14.35, 26.02; p < 0.00001)), whilst there was a tendency for lower re-operation requirements following AW (OR 0.64, 95% CI 0.26, 1.57, p = 0.44). CONCLUSIONS: AW was associated with equivalent to superior post-operative function and lower requirement for further intervention compared with OW. Results need to be interpreted cautiously, taking into consideration the methodological and clinical heterogeneity of the included studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2022, CRD42022364062.

Clinical and radiological septic joint analysis of spontaneous sternoclavicular joint infections: achieving the best outcomes-a systems engineering approach.

OBJECTIVES: Spontaneous sternoclavicular joint infection (SSCJI) is a rare and poorly understood disease process. This study aims to identify factors guiding effective management strategies for SSCJI by using data mining. METHODS: An Institutional Review Board-approved retrospective review of patients from 2 large hospitals (2010-2022) was conducted. SSCJI is defined as a joint infection without direct trauma or radiation, direct instrumentation or contiguous spread. An interdisciplinary team consisting of thoracic surgeons, radiologists, infectious disease specialists, orthopaedic surgeons, hospital information experts and systems engineers selected relevant variables. Small set data mining algorithms, utilizing systems engineering, were employed to assess the impact of variables on patient outcomes. RESULTS: A total of 73 variables were chosen and 54 analysed against 11 different outcomes. Forty-seven patients [mean age 51 (22-82); 77% male] met criteria. Among them, 34 underwent early joint surgical resection (<14 days), 5 patients received delayed surgical intervention (>14 days) and 8 had antibiotic-only management. The antibiotic-only group had comparable outcomes. Indicators of poor outcomes were soft tissue fluid >4.5 cm, previous SSCJI, moderate/significant bony fragments, HgbA1c >13.9% and moderate/significant bony sclerosis. CONCLUSIONS: This study suggests that targeted antibiotic-only therapy should be considered initially for SSCJI cases while concurrently managing comorbidities. Patients displaying indicators of poor outcomes or no symptomatic improvement after antibiotic-only therapy should be considered for surgical joint resection.

Extrapulmonary, Chronic Septic Arthritis From Mycobacterium tuberculosis in the Ankle and Subtalar Joints.

In the United States, rates of Mycobacterium tuberculosis infection have been declining for decades. Osteoarticular tuberculosis of the ankle is rarely observed. We present the case of a 65-year-old man who immigrated to the United States from India 24 years before the onset of symptoms. The patient initially reported atraumatic swelling and pain of the left ankle and foot and was treated for venous insufficiency. Later, the patient was referred to a nonsurgical orthopaedic clinic for additional workup and was found to have elevated inflammatory markers. MRI showed septic arthritis and osteomyelitis of the talus, distal tibia, and calcaneus. Joint aspiration revealed elevated white blood cell counts with predominately PMNs. The patient was then referred to an orthopaedic foot and ankle surgeon and underwent extensive irrigation and débridement. The patient was discharged on empiric antibiotics. Culture results from the original joint aspirate returned 14 days after surgery as positive for acid-fast bacillus, later identified as M tuberculosis by sequencing. Empiric antibiotics were discontinued, and the patient was started on appropriate antituberculotic therapy. This case report illustrates the challenge in the diagnosis of skeletal tuberculosis and the importance of including this condition on the differential for patients with atypical foot and ankle presentations.

Systematic review and meta-analysis of single-stage vs two-stage revision for periprosthetic joint infection: a call for a prospective randomized trial.

BACKGROUND: Periprosthetic joint infection (PJI) is a severe complication of joint arthroplasty that causes significant pain and economic loss. This study aimed to determine whether the current evidence supports single-stage revision for PJI based on reinfection and reoperation rates. METHODS: We searched the PubMed, EBSCO, Medline, and Cochrane Library databases from inception to 30 May 2023 to identify studies that compared single-stage revision and two-stage revision for PJI. Data on reinfection and reoperation rates were pooled. RESULTS: This meta-analysis included a total of 40 studies with 8711 patients. Overall, there was no significant difference between single- and two-stage revision regarding the postoperative reinfection rate and reoperation rate. Subgroup analysis by surgery period and different surgical sites revealed no difference between the two groups in the reinfection and reoperation rates. CONCLUSIONS: Based on the available evidence, our study did not identify a significant difference in reinfection and reoperation rates between single- and two-stage revision for PJI. Given the limitations in inclusion/exclusion criteria and the observed heterogeneity, we acknowledge the complexity of drawing strong conclusions. Therefore, we suggest that the choice between single- and two-stage revision should be carefully considered on an individual basis, taking into account patient-specific factors and further research developments.

Limited value of platelet-related markers in diagnosing periprosthetic joint infection.

OBJECTIVE: To evaluate the diagnostic values of serum platelet count (PC), mean platelet volume ratio (MPV), platelet count to mean platelet volume ratio (PVR), platelet to lymphocyte ratio (PLR), platelet to neutrophil ratio (PNR), PC/Albumin-globulin ratio (PC/AGR), and PC/C-reactive protein (PC/ CRP) in the diagnosis of periprosthetic joint infection (PJI). METHODS: The medical records were retrospectively analyzed of the 158 patients who had undergone hip or knee revisions from January 2018 to May 2022. Of them, 79 cases were diagnosed with PJI and 79 with aseptic loosening (AL). PJI was defined using the Musculoskeletal Infection Society criteria. The plasma levels of CRP, the erythrocyte sedimentation rate (ESR), PC, MPV, PVR, PLR, PNR, PC/AGR, and PC/CRP in the 2 groups were recorded and analyzed. In addition, tests were performed according to different joint types. The receiver operating characteristic curve was used to calculate the sensitivity and specificity of each indicator. The diagnostic value for each indicator was calculated according to the area under the curve (AUC). RESULTS: The PC, PVR, PLR and PC/AGR levels in the PJI group were significantly higher than those in the AL group, while PC/CRP levels were significantly lower (P < 0.001). The AUC for PC/CRP, and PC/AGR was 0.804 and 0.802, respectively, which were slightly lower than that of CRP (0.826) and ESR (0.846). ROC analysis for PC/CRP, and PC/AGR revealed a cut-off value of 37.80 and 160.63, respectively, which provided a sensitivity of 73.42% and 84.81% and a specificity of 75.95% and 65.82% for PJI. The area under the curve of PLR and PC was 0.738 and 0.702. The area under the curve values for PVR, PNR, and MPV were 0.672, 0.553, and 0.544, respectively. CONCLUSIONS: The results of this study suggest that PC, PLR, PC/CRP, and PC/AGR values do not offer significant advantages over ESR or CRP values when employed for the diagnosis of PJI. PVR, PNR, and MPV were not reliable in the diagnosis of PJI.

Optimal reimplantation timing in two-stage exchange for periprosthetic joint infection: an observative cohort study in Asian population.

BACKGROUND: The optimal timing for reimplantation for periprosthetic joint infection (PJI) has not been established and varies from a few weeks to several months. The aim of this study was to assess the commendable time between implant removal and reimplantation in patients who underwent two-stage exchange arthroplasty for PJI. METHODS: We retrospectively reviewed 361 patients who were treated with two-stage exchange arthroplasty for hip and knee chronic PJI at our institution between January 2000 and December 2018. Patient characteristics, comorbidities, surgical variables, microbiology data, and time to reimplantation were recorded. All patients were followed for a minimum of one year. Treatment failure was defined by Delphi criteria. Logistic regression analyses were used to calculate survival rates and adjusted odds ratios (ORs) of treatment failure. RESULTS: In final analysis, 27 (7.5%) had treatment failure. Factors related to treatment failure including interim spacer exchange (OR, 3.13; confidence interval (CI), 1.04-9.09, p = 0.036), higher ESR level at reimplantation (OR, 1.85; CI, 1.05-3.57; p = 0.04), and time to reimplantation (OR, 1.00; CI, 1.003-1.005, p = 0.04). Performing revision arthroplasty surgery from 16 to 20 weeks had highest successful rate. The reimplantation over 24 weeks had a lower successful rate. However, no statistical significance in comparing each interval group. CONCLUSION: Our study emphasized the importance of timely reimplantation in achieving successful outcomes. Factors such as ESR levels, spacer exchange, and the duration of time to reimplantation influenced the likelihood of treatment failure in two-stage exchange arthroplasty for hip and knee PJI.

Editorial Commentary: Arthroscopic Irrigation and Debridement is an Effective Treatment for Acute Septic Arthritis of Native Joints.

Arthroscopic irrigation and debridement has long been known to be an effective treatment for acute septic arthritis of native joints. Systematic review shows that when compared to open irrigation and debridement, arthroscopy yields comparable hospital length of stay complication, reoperation, and readmission rates, as well as better patient-reported outcomes compared to open arthrotomy. However, reoperation rates are heterogeneously defined in the literature, not to mention that unplanned return to surgery likely suggests inadequate prior irrigation and debridement of an infection, whereas a planned repeat washout may be a surgeon's intention and practice for septic arthritis. Most of all, this condition should be managed urgently.

Consensus on the definition and criteria for failure of surgical treatment in bacterial arthritis of a native joint: An international Delphi study.

PURPOSE: The literature presents a wide range of success rates for a single surgical intervention of bacterial-septic-arthritis, and there is a lack of clear criteria for identifying treatment failure and making decisions about reintervention. This Delphi study aims to establish a consensus among an international panel of experts regarding the definition of treatment failure and the criteria for reintervention in case of bacterial arthritis. METHODS: The conducting and reporting Delphi studies (CREDES) criteria were used. Data from a systematic review was provided as the basis for the study. A list of 100 potential experts were identified. The study was designed and conducted as follows: (I) identification and invitation of an expert panel, (II) informing the participating expert panel on the research question and subject, and (III) conducting two or three Delphi rounds to reach consensus on explicit research items. Potential criteria were rated on a five-point Likert scale. RESULTS: Sixty orthopaedic experts from nine countries participated in this Delphi study, with 55 completing all three rounds. The mean experience as an orthopaedic surgeon was 15 years (SD ± 9). Strong (96%) consensus was reached on the definition of treatment failure: the persistence of physical signs of arthritis (e.g., pain and swelling) and/or systemic inflammation (e.g., fever and no improvement in CRP) despite surgical and antibiotic treatment. Furthermore, consensus (>80%) was reached on six criteria influencing the decision for reintervention; pain (81%), sepsis (98%), fever (88%), serum CRP (93%), blood culture (82%), and synovial fluid culture (84%). CONCLUSION: The definition of treatment failure for bacterial arthritis after a single surgical intervention was established through a three-round Delphi study. Additionally, consensus was reached on six criteria that are helpful for determining the need for reintervention. This definition and these criteria may help in the development of clinical guidelines, and will empower physicians to make more precise and consistent decisions regarding reintervention for patients, ultimately aiming to reduce over- and undertreatment and improve patient outcomes. LEVEL OF EVIDENCE: Level V.

The Use of Artificial Intelligence for the Prediction of Periprosthetic Joint Infection Following Aseptic Revision Total Knee Arthroplasty.

Periprosthetic joint infection (PJI) following revision total knee arthroplasty (TKA) for aseptic failure is associated with poor outcomes, patient morbidity, and high health care expenditures. The aim of this study was to develop novel machine learning algorithms for the prediction of PJI following revision TKA for patients with aseptic indications for revision surgery. A single-institution database consisting of 1,432 consecutive revision TKA patients with aseptic etiologies was retrospectively identified. The patient cohort included 208 patients (14.5%) who underwent re-revision surgery for PJI. Three machine learning algorithms (artificial neural networks, support vector machines, k-nearest neighbors) were developed to predict this outcome and these models were assessed by discrimination, calibration, and decision curve analysis. This is a retrospective study. Among the three machine learning models, the neural network model achieved the best performance across discrimination (area under the receiver operating characteristic curve = 0.78), calibration, and decision curve analysis. The strongest predictors for PJI following revision TKA for aseptic reasons were prior open procedure prior to revision surgery, drug abuse, obesity, and diabetes. This study utilized machine learning as a tool for the prediction of PJI following revision TKA for aseptic failure with excellent performance. The validated machine learning models can aid surgeons in patient-specific risk stratifying to assist in preoperative counseling and clinical decision making for patients undergoing aseptic revision TKA.

Subchondral bone sequestrum formation in the proximal intra-articular and osteochondral region of the third metatarsal bone of an Appaloosa mare treated for septic arthritis.

OBJECTIVE: To raise awareness of the potential for intra-articular subchondral bone sequestrum formation secondary to a traumatic or septic process to enable more rapid identification of this uncommon but possible outcome in future cases. ANIMAL: A client-owned 12-year-old Appaloosa mare. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The mare had a wound to the lateral aspect of the fourth metatarsal bone (MT4) that communicated with the distal tarsal joints. Radiographs revealed a displaced, comminuted fracture of MT4. TREATMENT AND OUTCOME: The horse underwent aggressive debridement of the wound and MT4 as well as, on 2 occasions, needle joint lavage. Systemic, regional, and IA antibiotic therapy was also performed together with a bone graft from the tuber coxae. The horse's comfort improved, and the wound appeared to be healing. Five weeks following discharge, the horse re-presented with a non-weight-bearing lameness and radiographs revealed marked osteomyelitis of the tarsometatarsal and distal intertarsal joints. Postmortem examination of the limb identified a sequestrum within the proximal articular surface of the third metatarsal bone. CLINICAL RELEVANCE: The present report highlights the importance of arthroscopic lavage to visualize the cartilage surface and the benefits of advanced imaging to detect associated changes within the bone earlier than conventional radiographs. To our knowledge, no reports exist of intra-articular subchondral bone sequestra in the tarsometatarsal joint in horses.

Adjuvant intra-articular vancomycin for recalcitrant Staphylococcal prosthetic joint infections of the knee.

OBJECTIVE: Chronic prosthetic joint infection patients who fail conventional two-stage revision surgery are an especially difficult to treat patient population. Consequently, the objective of this study was to investigate the safety and long-term effectiveness of adjuvant intra-articular vancomycin therapy in conjunction with two-stage revision knee arthroplasties for recalcitrant Staphylococcal prosthetic joint infections. METHODS: This was an observational cohort study of twelve patients with recalcitrant Staphylococcal prosthetic joint infections of the knee which had failed previous revision surgeries. Each patient subsequently underwent two-stage revision with placement of Hickman catheters to deliver intra-articular vancomycin therapy. In addition, systemic antibiotic therapy was administered for 6 weeks, and long-term follow-up was evaluated then for 5 years. RESULTS: Seventy-five percent of the cohort have had no recurrence of their infections at 5 years. Two patients formed fistulas requiring above the knee amputations, and three patients had acute kidney injury. All patients had maximum measurable serum vancomycin trough levels that ranged from 6.1 to 93.6 mcg/mL. CONCLUSION: The aggressive protocol used in this cohort with repeat two-stage revision surgery, intra-articular vancomycin and systemic antibiotics was able to prevent recurrence of infection in most patients, but higher than expected rates of acute kidney injury were observed in this study. Therefore, while intra-articular vancomycin therapy may have some effectiveness in treating recalcitrant prosthetic joint infections, its ability to eradicate all bacterial niduses is unproven, and clinicians should be cognizant of potential adverse events that can occur with this therapy.

Clinical Outcomes After Revision Hip Arthroplasty due to Prosthetic Joint Infection-A Single-Center Study of 369 Hips at a High-Volume Center With a Minimum of One Year Follow-Up.

BACKGROUND: Prosthetic joint infection (PJI) treatment decisions are traditionally based on treatment algorithms. There is, however, a lack of evidence to support the choice of these treatment algorithms. Therefore, we aimed to assess the one-year survival after PJI revision and compared different surgical strategies in a single-center setting. METHODS: Revisions of the hip due to PJI performed at our institution between January 2008 and September 2021 with at least one-year of follow-up were identified. In total, 134 debridement, antibiotics, and implant retentions (DAIRs), 114 one-stage revisions, and 121 two-stage revisions were performed. Infections were classified as early, acute hematogenous, and chronic. Survival was calculated using the Kaplan-Meier method and cumulative incidence function. Predictors of outcomes were examined with Fine-Gray regressions and Cox proportional hazards regressions. Subdistribution hazard ratios and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. RESULTS: At one-year follow-up, 26.6% (CI 22.2 to 31.2%) of the patients had undergone reoperation and 7.9% (CI 5.4 to 10.9%) had died. The risk for reoperation was highest after DAIR (36.6%, CI 28.5 to 44.7%) and lowest after one-stage revision (20.2%, CI 13.4 to 28%). Within the early infections, the one-stage revision almost halved the risk of reoperation (HR 0.51, CI 0.31 to 0.84) with no added mortality risk (HR 1.05, CI 0.5 to 2.2), when compared to DAIR. CONCLUSION: By utilizing 1-stage revision over DAIR in early infections, it might be possible to improve the prognosis by decreasing the risk of reoperation without increasing mortality. However, as the patient selection is undeniably difficult, more research is warranted.

Unexpected positive cultures in patients with arthrofibrosis following total hip and total knee arthroplasty.

PURPOSE: It has been suggested that low-grade infections could be the cause of arthrofibrosis. However, this hypothesis has not been conclusively proven. The aim of this study is to assess the incidence of unexpected positive cultures (UPC) in patients undergoing revision total joint arthroplasty for a diagnosis of arthrofibrosis. METHODS: A retrospective single-centre review was performed. All patients who underwent an aseptic revision due to histologically confirmed arthrofibrosis (based on the synovial-like interface membrane (SLIM) criteria) were included. The incidence of UPC was then calculated. RESULTS: A total of 147 patients were included. Of these, 100 underwent a total knee arthroplasty (TKA) procedure and 46 a total hip arthroplasty (THA) surgery. One patient had a periprosthetic joint infection and was therefore excluded. Of the 146 included patients, 6 had confirmed UPC (4.08%). The following bacteria were identified: Anaerococcus octavius, Staphylococcus epidermidis, Enterobacter cloacae, Staphylococcus hominis, Streptococcus pluranimalium, Staphylococcus pettenkoferi. CONCLUSIONS: Our results suggest that the incidence of UPC in patients with arthrofibrosis is low. It is lower than that of UPC in patients that undergo a revision for other causes. There is no proven relationship between histologically confirmed arthrofibrosis following total joint arthroplasty and prosthetic joint infection.

Detection of Cutibacterium (Propionibacterium) acnes in orthopaedic surgery: serious problem or contamination?

PURPOSE: Bone and joint infections are an important and increasing problem. Whether intraoperatively detected bacteria should be considered relevant or not is often difficult to assess. This retrospective cohort study analyzes the relevance of C. acnes cultured from deep intraoperative specimens. METHODS: All deep tissue samples collected intraoperatively between 2015 and 2020 from a quartiary care provider were evaluated for detection of C. acnes and its therapeutical consequences. Infection rates were determined according to a standardized definition and protocol and analyzed in dependence of patient's demographic data (age and gender), operative parameters (type of surgery, body region/location of surgery, and impression of the surgeon), and initiated therapy. RESULTS: In 270 cases of more than 8500 samples, C. acnes was detected. In 30%, the detection was considered an infection. The number of samples taken and tested positive for C. acnes correlated significantly with its classification as a cause of infection. If more than one sample of the patient was positive, the detection was significantly more likely to be treated as infection (p < 0.001). In 76% of cases, a consultation to the infectious diseases (ID) department took place regarding the classification of the pathogen detection and the therapy to be carried out. Almost all of the tested isolates demonstrated the wild-type susceptibility for penicillin and clindamycin. CONCLUSION: Intraoperative detection of skin-colonizing bacteria such as C. acnes is not always synonymous with infection. In particular, if other examination results contradict an infection (pathological sample without evidence of an infectious event, detection of malignant cells, etc.), the situation must be considered in a very differentiated manner. Interdisciplinary boards, for example, are suitable for this purpose. Care should be taken to obtain a sufficiently large number of tissue samples for microbiological examination to be able to better classify the result.

Treatment of intractable septic ankle arthritis with a continuous closed irrigation system.

OBJECTIVES: The study aimed to evaluate the efficacy of a continuous closed irrigation system (CCIS) after open debridement for patients with intractable septic ankle arthritis. PATIENTS AND METHODS: The retrospective study analyzed the intractable septic arthritis of 12 (6 males, 6 females; mean age: 64.1±14.7 years; range, 33 to 80 years) patients managed by CCIS between July 2015 and July 2020. All patients had previously undergone operations to treat septic ankle arthritis without resolution of the infection. After open debridement, the CCIS was usually equipped with two outflow tubes and one inflow tube. Saline inflow was about 1 L per day. RESULTS: The mean follow-up period was 30.8±14.9 (range, 15 to 70) months. The CCIS was maintained for a mean of 5.1±2.1 (range, 3 to 7) days. The mean number of operations the patients had previously undergone was 2.83±1.5 (range, 1 to 6). For 11 (91.6%) out of 12 patients, infection did not recur after one-time CCIS, and laboratory test results remained normal. Six patients had previously undergone total ankle replacement arthroplasty. These patients underwent antibiotics-mixed cement arthroplasty after CCIS. For five of six with infected total ankle replacement arthroplasty, infection did not recur after CCIS. However, one patient without the removal of both implants experienced recurrence at the same site after four postoperative months. In the reoperation, after the removal of both implants and the application of antibiotics-mixed cement arthroplasty, the infection was cleared. CONCLUSION: Use of CCIS after open debridement for intractable septic ankle arthritis is a good treatment option since it is relatively simple and safe, with good results.

Neutrophil to Lymphocyte Ratio as an Indicator of Periprosthetic Joint Infection: A Retrospective Cohort Study.

INTRODUCTION: Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication posing notable clinical implications for patients and substantial economic burdens. Neutrophil to lymphocyte ratio (NLR) is an emerging biomarker of inflammation, which may better predict PJI. The objective of this review was to evaluate NLR changes in patients with confirmed PJI, to compare NLR between an aseptic revision and a revision for PJI, and to establish whether an NLR of 2.45 is an appropriate cutoff for predicting infection. METHODS: A retrospective review of patients who underwent revision TJA for PJI at a single center between January 1, 2005, and December 31, 2018, was performed and compared with an aseptic cohort who underwent aseptic revision TJA. NLR was calculated from complete blood counts performed at index surgery and at the time of revision surgery. Receiver operating characteristic curves were analyzed, along with sensitivity, specificity, and positive and negative likelihood ratios. RESULTS: There were 89 patients included in each cohort. Mean NLR in patients who underwent revision for PJI was 2.85 (± 1.27) at the time of index surgery and 6.89 (± 6.64) at the time of revision surgery ( P = 0.017). Mean NLR in patients undergoing revision for PJI (6.89) was significantly higher than aseptic revisions (3.17; P < 0.001). DISCUSSION: In patients who underwent revision surgery for PJI, NLR was markedly elevated at time of revision compared with the time of index surgery. Because it is a cost-effective and readily available test, these findings suggest that NLR may be a useful triage test in the diagnosis of PJI. LEVEL OF EVIDENCE: Level III Diagnostic Study.

Can C-Reactive Protein-Lymphocyte Ratio Be Used as a Screening Tool to Confirm the Diagnosis of Periprosthetic Joint Infection?

Background: This study aimed to investigate whether periprosthetic joint infection (PJI) can be predicted by the C-reactive protein-to-lymphocyte ratio (CLR), whether this ratio increases the accuracy of PJI diagnosis, and whether it is more sensitive than other blood values and ratios. Methods: The patients were divided into two groups: the septic revision (SR) group and the aseptic revision (AR) group. In cases of septic revision, the diagnosis of PJI was made based on the criteria proposed by the European Bone and Joint Infection Society (EBJIS). The groups were compared in terms of age, sex, body mass index, comorbidity, and preoperative laboratory results. The sensitivity, specificity, and diagnostic performance of the values and ratios were analyzed and compared. Results: The receiver operating characteristic (ROC) analysis for the CLR gave a diagnostic value of 15.52, which provided a sensitivity of 91.1% and a specificity of 64.2% for PJI. The CLR gave lower specificity and higher sensitivity compared to the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. The ROC analysis showed that the CLR had a similar area under the curve (AUC) with the ESR and CRP (0.808). The CLR had a higher specificity than other ratios (platelet volume ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio) and a higher value of the AUC. In the multivariate analysis, the CLR (hazard ratio, 1.088; 95% confidence interval, 1.063-1.113; p < 0.001) was found to be a significant risk factor. As CLR increased by one unit, the risk of PJI increased by 1.088 times, and it was statistically significant (p < 0.001). Conclusions: The findings of this study suggest that CLR can serve as a valuable screening tool for diagnosing PJI. CLR demonstrated higher sensitivity in predicting PJI compared to ESR and CRP, and it exhibited greater specificity than other infection markers.

Septic Arthritis of the Pubic Symphysis in a 16-Year-Old Male Adolescent: A Case Report.

CASE: A 16-year-old male adolescent presented with 4 weeks of right-sided hip pain and fever in the setting of recent groin trauma. He was diagnosed with septic arthritis of the pubic symphysis (SAPS) and was treated nonoperatively with antibiotics. Symptoms recurred, and he underwent surgical drainage of the pubic symphysis followed by a prolonged course of antibiotics. Follow-up at 12 months indicated complete symptom resolution. CONCLUSION: This is the ninth reported adolescent case of SAPS. Although the presentation and disease course closely resembled those reported in the literature, this is the only case that required surgical intervention after failed nonoperative management.

Temporal trends in revision rate due to knee periprosthetic joint infection: a study of 115,120 cases from the Danish Knee Arthroplasty Register.

BACKGROUND AND PURPOSE: We aimed to examine the temporal trends in periprosthetic joint infection (PJI) revision incidence after knee arthroplasty (KA) from 1997 through 2019. PATIENTS AND METHODS: 115,120 primary KA cases from the Danish Knee Arthroplasty Register were followed until the first PJI revision. We computed cumulative incidences and adjusted hazard ratios (aHRs) of PJI revision by calendar periods and several patient- and surgical-related risk factors. Results were analyzed from 0-3 months and from 3-12 months after KA. RESULTS: The overall 1-year PJI revision incidence was 0.7%, increasing from 0.5% to 0.7% (1997 through 2019). The incidence of PJI revision within 3 months increased from 0.1% to 0.5% (1997 through 2019). The adjusted hazard ratio (aHR) within 1 year of primary KA was 5.1 comparing 2017-2019 with 2001-2004. The PJI revision incidence from 3-12 months of KA decreased from 0.4% to 0.2%, with an aHR of 0.5 for 2017-2019 vs. 2001-2004. Male sex, age 75-84 (vs. 65-74), and extreme obesity (vs. normal weight) were positively associated with the risk of PJI revision within 3 months, whereas only male sex was associated from 3-12 months. Partial knee arthroplasty (PKA) vs. total KA was associated with a lower risk of PJI revision both within 3 months and 3-12 months of KA. CONCLUSION: We observed an increase in PJI revision within 3 months of KA, and a decrease in PJI revision incidence from 3-12 months from 1997 through 2019. The reasons for this observed time-trend are thought to be multifactorial. PKA was associated with a lower risk of PJI revision.

Early results of a novel modular knee arthrodesis implant after uncontrolled periprosthetic knee joint infection.

AIM: The aim of this study is to evaluate the functional outcomes and complications after non-fusion knee arthrodesis with a modular segmental intramedullary implant used for infected total knee arthroplasty revisions. METHODS: A retrospective review of the patients who had been surgically treated with a modular intramedullary arthrodesis implant for recurrent infection after revision TKA between January 2016 and February 2020 were included. The indications for arthrodesis were failed infected TKA with massive bone loss, deficient extensor mechanism and poor soft tissue coverage that precluded joint reconstruction with revision TKA implants. Clinical outcomes were assesed with visual analogue scale for pain (pVAS), Oxford knee score (OKS) and 12-item short form survey (SF-12). Full-length radiographs were used to verify limb length discrepancies (LLD). RESULTS: Fourteen patients (4 male and 10 female) patients with a mean age of 69.3 (range, 59 to 81) years at time of surgery were available for final follow-up at a mean of 28.8 months (range, 24-35 months). All clinical outcome scores improved at the final follow-up (pVAS, 8.5 to 2.6, p = .01; OKS, 12.6 to 33.8, p = .02; SF-12 physical, 22.9 to 32.1, p = .01 and SF-12 mental, 27.7 to 40.2, p = .01). The mean LLD was 1.0 cm (range, + 15 - 2.3 cm). Re-infection was detected in three patients (21.4%). Two patients were managed with suppressive antibiotic treatment and a third patient required repeat 2-stage revision procedure. In one patient, a periprosthetic femur fracture was observed and treated with plate osteosynthesis. CONCLUSION: Uncontrolled infection after total knee arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail and satisfactory functional results can be obtained. LEVEL OF EVIDENCE: Level 4, Retrospective cohort study.