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The Bone & Joint Journal
Vol. 96-B, Issue 11 | Pages 1566 - 1570
1 Nov 2014
Blackmur JP Tang EYH Dave J Simpson AHRW

We compared the use of broth culture medium for samples taken in theatre with the standard practice of placing tissue samples in universal containers. A total of 67 consecutive patients had standard multiple samples of deep tissue harvested at surgery and distributed equally in theatre either to standard universal containers or to broth culture medium. These samples were cultured by direct and enrichment methods. The addition of broth in theatre to standard practice led to an increase in sensitivity from 83% to 95% and an increase in negative predictive value from 77% to 91%. Placing tissue samples directly into broth in the operating theatre is a simple, inexpensive way to increase the sensitivity of cultures from infected patients, and does not appear to compromise the specificity of these cultures.

Cite this article: Bone Joint J 2014;96-B:1566–70.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 72 - 72
22 Nov 2024
Zouitni A van Oldenrijk J Bos K Croughs PD Yusuf E Veltman W
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Aim. Periprosthetic joint infection (PJI) is a serious complication after joint arthroplasty. Diagnosing PJI can be challenging as preoperative screening and conventional cultures may be inconclusive. Sonication fluid culturing stands out as a valuable adjunct technique to improve microbiological PJI diagnosis. This study aims to determine the clinical relevance of routinely using sonication for all septic and aseptic revisions. Method. All patients who underwent (partial) hip or knee revision arthroplasty for all causes between 2012 and 2021 at our institution were retrospectively reviewed. Based on the European Bone and Joint Society PJI criteria, we categorized them into three groups: infection confirmed, infection likely, and infection unlikely. We analyzed the clinical, laboratory, and radiological screening that could confirm or refute suspicion of PJI. We analyzed microbiology cultures and the most frequently detected microorganisms. Sensitivity and specificity were calculated for synovial fluid cultures (preoperative), tissue cultures, and sonication fluid cultures. We determined the clinical relevance of sonication as the percentage of patients for whom sonication confirmed (microbiological) PJI diagnosis. Results. 429 patients who underwent (partial) revision of hip (246 patients) or knee (183 patients) arthroplasty were included. Sensitivity and specificity were 69% and 99% for preoperative synovial fluid cultures, 76% and 92% for intraoperative tissue cultures, and 80% and 89% for sonication fluid cultures, respectively. Sonication fluid cultures improved tissue culture sensitivity and specificity to 83% and 99%, respectively. In 12 (11%) out of 110 PJIs, sonication fluid cultures were decisive for confirming the causative pathogen. This was applicable to acute and chronic infections. In 29 (9%) out of 319 aseptic cases, a negative sonication fluid culture could confirm contamination of tissue cultures. Conclusions. Routine sonication fluid cultures enhanced the sensitivity and specificity of PJI diagnostics. In 11% of PJI cases, causative pathogens were confirmed by sonication fluid culture results. Routine sonication may be helpful in confirming contamination of synovial fluid cultures and tissue cultures. Routine sonication fluid culture should be performed in all revision arthroplasties


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 73 - 73
22 Nov 2024
Erbeznik A Smrdel KS Kišek TC Cvitković-Špik V Triglav T Vodicar PM
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Aim. The aim of this study was to develop an in-house multiplex PCR real-time assay on the LightCycler 480 system (Roche, Basel, Switzerland) with the aim of rapid detection of common pathogens in prosthetic joint infections (PJI), followed by validation on clinical samples (sonication fluid and tissue biopsies) routinely collected for PJI diagnosis. Methods. Using the PrimerQuest and CLC WorkBench tool, we designed six primer sets with specific fluorescently labelled TaqMan probes for the nuc gene in different Staphylococcus species (S. aureus, S. epidermidis, S. capitis, S. lugdunensis, S. hominis, S. haemolyticus). In addition, primers previously developed by Renz et al. (2022) for C. acnes were integrated into our assay with internal control of isolation, leading to the development of specific mPCR assay with seven included targets. Analytical sensitivity and specificity were evaluated using reference bacterial strains. To determine the assay's limit of detection (LOD), we conducted serial dilutions of eluates containing known concentrations of bacterial DNA copies/µl. The overall LOD in spiked clinical samples, including sample preparation and DNA isolation on MagnaPure24, was measured through 10-fold serial dilutions (from 10. 9. to 10. -1. CFU/ml) including additional dilutions of 5000, 500, 50 and 5 CFU/ml. Results. The results with LOD in serial dilutions of eluates and spiked clinical samples, together with analytical sensitivity and specificity, are shown in Table 1. Conclusion. The mPCR assay showed excellent analytical sensitivity and specificity, but with considerably lower LOD after sample preparation and further DNA isolation in spiked clinical samples. Although still promising in diagnostics of acute infections, the use of mPCR could be challenging in chronic, low-grade infections with lower microbial burden. Nevertheless, PCR offers significant advantages in terms of speed and can shorten the time to result, especially for C. acnes infections. Additionally, it represents a promising complementary approach in patients with suspected PJI on antibiotic therapy with negative culture results. For any tables or figures, please contact the authors directly


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 41 - 41
22 Nov 2024
Copier B Visser D van Oldenrijk J Bos K Veltman W
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Aim. Periprosthetic joint infection (PJI) is a devasting complication after total hip arthroplasty. Joint aspiration and preoperative biopsy can be helpful diagnostics for PJI. The aim of this study is to evaluate the diagnostic value of preoperative biopsies after inconclusive or dry tap aspiration of the hip in patients undergoing revision hip arthroplasty. Secondarily we will evaluate the diagnostic value of synovial fluid aspiration cultures and peroperative tissue cultures for diagnosing or ruling out PJI. Methods. Patients who underwent diagnostic aspiration and subsequent preoperative biopsy and/or revision surgery between January 2015 and January 2024 were included in the study. Synovial fluid aspirations and tissue samples obtained from biopsy and revision surgery were interpreted using the European Bone and Joint Infection Society criteria for PJI and in close consultation with the microbiologist. Results. 207 Patients were included with 231 synovial fluid aspirations. Sensitivity and specificity of synovial fluid aspiration cultures were 76% and 98%. In 62 patients tissue biopsies were performed, of which 40 after a dry tap. The tissue biopsies after a dry tap aspiration had a sensitivity of 50.0% and a specificity of 95.8%. In 21% tissue biopsies led to the confirmation of PJI in patient with a high suspicion of PJI after dry tap aspiration. In patients with an inconclusive synovial fluid aspiration result the addition of tissue biopsies led to a change in treatment in 14%. In 212 cases revision surgery was performed, intraoperative tissue cultures had a sensitivity and specificity of 83.3% and 99.3%. Conclusions. Diagnosing PJI can be troublesome, especially if synovial fluid aspiration provides a dry tap. Tissue biopsy cultures in patients with a high suspicion of PJI after dry tap aspiration is a feasible way to confirm PJI, in 21% of patients PJI could be confirmed after dry tap aspiration. Ruling out PJI by means of a biopsy after a dry tap aspiration is less successful due to its low sensitivity. Tissue biopsies after an inconclusive aspiration leads to clinically important treatment changes


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 80 - 80
1 Oct 2022
Morovic P Karbysheva S Meller S Kirschbaum S Perka C Conen A Trampuz A
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Aim. Synovial fluid D-lactate may be useful for diagnosing septic arthritis (SA) as this biomarker is almost exclusively produced by bacteria. We evaluated the performance of synovial fluid D-lactate and determined its optimal cut-off value for diagnosing SA. Method. Consecutive patients with suspicion of septic arthritis were prospectively included. They underwent joint aspiration and synovial fluid was collected for culture, leukocyte count and D-lactate concentration (by spectrophotometry). Youden's J statistic was used for determining optimal D-lactate cut-off value on the receiver operating characteristic (ROC) curve by maximizing sensitivity and specificity. Results. A total of 155 patients were included. Using institutional criteria, 21 patients (14%) were diagnosed with SA and 134 (86%) patients with aseptic arthropathy, out of which 43 (27%) had osteoarthrosis, 80 (52%) had rheumatic arthropathy and 11 (7%) reactive arthritis. The optimal cut-off of synovial fluid D-lactate to differentiate SA from aseptic cases was 0,035 mmol/l. Synovial fluid D-lactate had a sensitivity 90% (95% CI: 70–99%) and specificity 87% (95% CI: 80–92%) compared to leukocyte count with sensitivity 81% (95% CI: 60–95%) and specificity 83% (95% CI: 76–90%). Culture was positive in only 17 (80%) out of 21 patients with SA. Conclusions. The synovial fluid D-lactate showed high sensitivity and specificity for diagnosis of SA which was higher than the current gold standard of diagnosis (culture and leukocyte count). The high sensitivity makes this biomarker useful as a point-of-care screening test for SA


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 20 - 20
1 Dec 2021
Schwarze J Theil C Gosheger G Lampe L Schneider KN Ackmann T Moellenbeck B Schmidt-Braekliing T Puetzler J
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Aim. Diagnosis and isolation of a causative organism is imperative for successful treatment of periprosthetic joint infections (PJI). While there are several diagnostic algorithms using microbiology, serum and synovial markers, the preoperative diagnosis of a low-grade infection remains a challenge, particularly in patients with unsuccessful aspiration. An incisional biopsy may be used in these cases as additional diagnostic tool. In this retrospective study we evaluated microbiological findings, sensitivity, and specificity of open synovial biopsies in cases of inconclusive preoperative diagnostics. Methods. In a retrospective databank analysis (2010–2018), we identified 80 TKAs that underwent an open biopsy because of inconclusive results after applying the CDC Criteria (2010) or the MSIS (2011–2018) for PJI. Infection makers in the serum (C-reactive protein [CRP], leucocytes count and interleukin-6 [IL-6]) and in the synovial aspirate (leucocyte count, percentage of neutrophiles) prior to the biopsy were analyzed. All biopsies were performed by suprapatellar mini-arthrotomy. If a subsequent revision surgery was performed, the isolated organisms in the open biopsy were compared to the results in the revision surgery and sensitivity and specificity were calculated. Serum markers were checked for correlation with a positive result in the open biopsy using Cramer-V and Chi. 2. -Test. Results. A positive result in the open biopsy occurred in 32 cases (40%) while 48 cases (60%) showed no growth of microorganisms. A preoperative elevated serum CRP (≥1mg/dl) showed a significant correlation for a positive biopsy (p=0.04). The odds ratio for a positive biopsy was 2.57 (95% CI 1.02–6.46) with elevated serum CRP. A revision surgery of the TKA with additional tissue sampling was performed in 27 (84%) cases with a positive biopsy and in 32 (67%) cases with a negative biopsy. The intraoperative tissue samples from the revision surgery showed microbial growth in only 52% of cases that were believed to be culture positive from the biopsy results, while positive cultures occurred in 41% of the cases with an initially negative biopsy. Patients with ≥ two cultures of the same microorganism in the biopsy presented a positive result in 73% of their revision surgeries. The open biopsy showed a sensitivity of 48% with a specificity of 62% in our collective if revision surgery was performed. Conclusion. Open biopsy may be considered with inconclusive preoperative serum and synovial fluid diagnostics for PJI, but sensitivity and specificity were rather low in this special collective. Further studies with bigger collectives should be performed to determine potential markers with a higher sensitivity


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 18 - 18
1 Dec 2021
Warren J Anis H Bowers K Villa J Pannu T Klika AK Piuzzi N Colon-Franco J Higuera-Rueda C
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Aim. Several options to standardize the definition of periprosthetic joint infection (PJI) have been created including the 2013 Musculoskeletal Infection Society (MSIS), 2018 Intentional Consensus Meeting (ICM), and the 2019 proposed European Bone and Joint Infection Society (EBJIS) criteria. Synovial fluid biomarkers have been investigated in an effort to simplify and improve the diagnosis of PJI. The aim of this study was to test the sensitivity, specificity, positive, and negative predicted values (PPV and NPV, respectively) of a calprotectin point of care (POC) test for diagnosing PJI in revision total knee arthroplasty (TKA) patients comparing different sets of criteria (2013 MSIS, 2018 ICM, and 2019 EBJIS criteria) used to define patients as with or without infection. Method. From October 2018 to January 2020 and under IRB approval 123 intraoperative samples of synovial fluid were prospectively collected at two academic hospitals in the same institution from revision TKA patients. All patients underwent standard clinical and laboratory evaluation for PJI at our institution, allowing for categorization using the 3 criteria. Patients were adjudicated by 2 blinded and independent reviewers for the 3 sets of criteria. The 3 criteria agreed 91.8% of the time. Four likely cases by the 2019 proposed EBJIS were considered unlikely and 1 inconclusive case by the 2018 ICM was considered not infected for the purposes of analysis. Calprotectin POC testing followed manufacturer's instructions using a threshold of >50 mg/L to indicate PJI. Sensitivities, specificities, PPV, NPV, and areas under the curve (AUC) were calculated for the 3 sets of criteria. Results. Using 2013 MSIS criteria the calprotectin POC test demonstrated a sensitivity, specificity, PPV, NPV AUC of 98.1%, 95.7%, 94.5%, 98.5%, and 0.969, respectively. Using 2018 ICM the POC test demonstrated a sensitivity, specificity, PPV, NPV and (AUC) of 98.2%, 98.5%, 98.2%, 98.5%, and 0.984, respectively. Using the 2019 proposed EBJIS criteria the POC test demonstrated a sensitivity, specificity, PPV, NPV and area under the curve (AUC) of 93.2%, 100.0%, 100.0%, 94.2%, and 0.966, respectively. Conclusions. The calprotectin lateral flow POC test has an excellent sensitivity and specificity regardless of the set of criteria used to define PJI. These results are promising and suggest that the calprotectin lateral flow test may be used as a rule out test in a cost-conscious health care model or when conventional diagnostic tools may not be available. Further investigations of the calprotectin PCO test must be completed to validate these results


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 67 - 67
24 Nov 2023
Gardete-Hartmann S Simon S Frank BJ Sebastian S Loew M Sommer I Hofstaetter J
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Aim. Synovial calprotectin point-of-care test (POC) has shown promising clinical value in diagnosing periprosthetic joint infections (PJIs). However, limited data are available in unclear cases. Moreover, cut-off values for calprotectin lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) need to be adapted. The aim of this study was to evaluate the performance of an upgraded and more sensitive version of a synovial calprotectin LFA along with ELISA immunoassay in patients with septic, aseptic, and unclear cases. Methods. Overall, 206 prospectively collected periprosthetic synovial fluid samples from 169 patients (106f/63m; 38 hip/131 knee) who underwent revision surgeries were retrospectively evaluated for calprotectin concentration. The following groups were analyzed: unexpected negative cultures (UNC; 32/206), unexpected positive cultures (UPC; 28/206), and unclear cases (65/206) with conflicting clinical results. In addition, we added a true aseptic (40/206), and true septic (41/206) control groups according to the international consensus meeting (ICM) 2018 PJI classification. Calprotectin concentration was determined by a rapid quantitative LFA (n=206) (Lyfstone®, Norway), and compared to calprotectin ELISA immunoassay (171/206). For the determination of a new calprotectin cut-off value, analysis of the area under the curve (AUC) followed by Youden's J statistic were performed using the calproctectin values from clear septic and aseptic cases. Sensitivity and specificity for calprotectin were calculated. All statistical analyses were performed using IBM-SPSS® version 25 (Armonk, NY, USA). Results. An absolute calprotectin value of 43 mg/ml, and 40.15 mg/ml was determined to be the optimal cut-off for PJI diagnosis using the new version of the LFA and ELISA, respectively. With this cut-off, the sensitivity and specificity of synovial calprotectin concentration for PJI were 88.1% (95% CI 77.8 to 94.7) and 76.6% (95% CI 61.9 to 87.7) for LFA, and 97.06% (95% CI 89.8 to 99.64) and 93.6% (95% CI 82.5 to 98.66) for ELISA, respectively. Of the evaluated groups, UNC 30/32 (93.8%) vs 26/27 (96.3%), UPC 6/28 (21.4%) vs 4/21 (19%), and unclear samples 45/65 (69.2%) vs 30/56 (53.6%) displayed a high likelihood of infection by using LFA, and ELISA, respectively. Conclusion. The upgraded version of the calprotectin quantitative LFA with a new suggested cut-off for infected samples showed additional clinical value in identifying cases at high risk of infection in unclear PJI revisions. Additionally, calprotectin ELISA immunoassay had a better performance than LFA. Further large sample-size validation studies are warranted


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 71 - 71
22 Nov 2024
Cobra H Mozella A Leal AC
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Aim. Periprosthetic joint infection (PJI) is one of the most frequent and devastating complications of total knee arthroplasty (TKA). Accurate diagnosis and proper treatment are essential to prevent functional loss and progression to systemic infection. However, the correct diagnosis of PJI is still a challenge since there is no accurate diagnostic method and the existing diagnostic criteria are based on serological, histological and microbiological tests that are imprecise and time-consuming. Recently, it was demonstrated that cell-free DNA is increased in the synovial fluid of patients with PJI. Therefore, this study aims to evaluate a new point-of-care methodology for quantifying free DNA in synovial fluid. Method. A prospective study was carried out with patients undergoing TKA revision surgery, from whom it was possible to collect synovial fluid (SF) during the surgical procedure. Cell-free DNA quantification was performed directly from the SF, using a portable fluorimeter. Sensitivity, specificity and receiver operating characteristic (ROC) curve were calculated. Results. Fifty-four patients were included in the study, of which 25 were diagnosed with PJI. Cell-free DNA levels measured immediately after collection were increased in the synovial fluid of patients with PJI (26.3 ± 14.8) in comparison with the uninfected group (4.6 ng/ml ± 3.8, p< 0.0001). The area under the receiver operating characteristic curve (AUC ROC) was 0.981 (95% CI 0.914 to 0.999). Conclusions. From the results presented, we can conclude that the quantification of free DNA with a portable fluorimeter proved to be a test with high sensitivity and specificity for the diagnosis of PJI


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 66 - 66
24 Nov 2023
d'Epenoux Louise R Robert M Caillon H Crenn V Dejoie T Lecomte R Tessier E Corvec S Bemer P
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Background. The diagnosis of periprosthetic joint infection (PJI) remains a challenge in clinical practice and the analysis of synovial fluid (SF) is a useful diagnostic tool. Recently, two synovial biomarkers (leukocyte esterase (LE) strip test, alpha-defensin (AD)) have been introduced into the MSIS (MusculoSkeletal Infection Society) algorithm for the diagnosis of PJI. AD, although promising with high sensitivity and specificity, remains expensive. Calprotectin is another protein released upon activation of articular neutrophils. The determination of calprotectin and joint CRP is feasible in a routine laboratory practice with low cost. Purpose. Our objective was to evaluate different synovial biomarkers (calprotectin, LE, CRP) for the diagnosis of PJI. Methods. In this monocentric study, we collected SF from hip, knee, ankle and shoulder joints of 42 patients who underwent revision or puncture for diagnostic purposes. Exclusion criteria included a joint surgery in the previous 3 months and a diagnosis of a systemic inflammatory disease. PJI was diagnosed in a multidisciplinary consultation meeting (RCP) of the Reference Centers for Osteoarticular Infections of the Great West (CRIOGO). SF was analysed for LE, CRP and calprotectin. The cut-off values used were 50 mg/L for calprotectin, 8.8 mg/L for CRP and 125 WBC/µL for LE. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for these different synovial markers. Results. Of the 42 patients included, 28 were considered as infected and 14 uninfected. The statistical parameters are presented in Table 1. Conclusion. The present study shows that the synovial calprotectin assay has an excellent sensitivity and a 100% NPV for the diagnosis of PJI, suggesting that a result < 50 mg/L could exclude PJI. This promising study suggests that calprotectin should be included with synovial CRP in a new decision algorithm for the diagnosis of PJI. For any tables or figures, please contact the authors directly


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 43 - 43
22 Nov 2024
Bekkers W Zwart V Swietoslawki A Oost IK Nijs A Emmen J Van Geenen R
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Aim. Periprosthetic joint infection (PJI) is one of the main reasons for revision surgery after primary unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA) or total hip arthroplasty (THA). Currently the MSIS and EBJIS criteria sets are considered to be the gold standards in determining PJI. These criteria sets are complex and contain tests that are time-consuming and many are rather costly. Therefore, further research is indicated to find a simpler but equally reliable diagnostic test. In this study we evaluated the additional value of calprotectine measurement in synovial fluid in patients undergoing hip and knee (revision) arthroplasty following routine work-up. Method. In a retrospective cohort study, we analyzed 182 synovial fluid samples from 143 patients with suspected PJI after UKA, TKA, THA or revision arthroplasty. Twenty-six of those cases were classified as PJI according to the MSIS and EBJIS criteria. Subsequently, synovial calprotectin was determined, using a lateral flow assay and two cut-off thresholds of ≥14 mg/L and ≥50 mg/L. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of synovial calprotectin was determined. Results. When applying the MSIS and EBJIS criteria and a calprotectin level ≥14 mg/L, synovial calprotectin revealed an area under the curve of 0.96 (95% CI 0.90-1.00), with 92.3% sensitivity and 100% specificity. The PPV and NPV were 100% and 92.9% respectively. When applying the MSIS and EBJIS criteria and a calprotectin level ≥ 50 mg/L, synovial calprotectin revealed an area under the curve of 0.94 (95% CI 0.87-1.00), with 88.5% sensitivity and 100% specificity. The PPV and NPV were 100% and 89.7% respectively. Conclusions. The value of calprotectin in synovial fluid gives valuable information with a single test result, resulting in high predictive value in the diagnosis of PJI after hip or knee arthroplasty and should seriously be considered as part of PJI diagnostics in an outpatient clinical setting. The high specificity can help rule in patients that are suspected of PJI. Therefor this test can be helpful in a preop diagnostic work-up to avoid unnecessary revisions in patients with well-placed and well-fixed arthroplasties with a suspected PJI. These conclusions are independent of which criteria set was used as a gold standard


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 71 - 71
24 Nov 2023
Heesterbeek P Pruijn N Boks S van Bokhoven S Dorrestijn O Schreurs W Telgt D
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Aim. Diagnosis of periprosthetic shoulder infections (PSI) is difficult as they are mostly caused by low-virulent bacteria and patients do not show typical infection signs, such as elevated blood markers, wound leakage, or red and swollen skin. Ultrasound-guided biopsies for culture may therefore be an alternative for mini-open biopsies as less costly and invasive method. The aim of this study was to determine the diagnostic value and reliability of ultrasound-guided biopsies for cultures alone and in combination polymerase chain reaction (PCR), and/or synovial markers for preoperative diagnosis of PSI in patients undergoing revision shoulder surgery. Method. A prospective explorative diagnostic cohort study was performed including patients undergoing revision shoulder replacement surgery. A shoulder puncture was taken preoperatively before incision to collect synovial fluid for interleukin-6 (IL-6), calprotectin, WBC, polymorphonuclear cells determination. Prior to revision surgery, six ultrasound-guided synovial tissue biopsies were collected for culture and two additional for PCR analysis. Six routine care tissue biopsies were taken during revision surgery and served as reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV; primary outcome measure), and accuracy were calculated for ultrasound-guided biopsies, and synovial markers, and combinations of these. Results. Fifty-five patients were included. In 24 patients, routine tissue cultures were positive for infection. Cultures from ultrasound-guided biopsies diagnosed an infection in 7 of these patients, yielding a sensitivity, specificity, PPV, NPV, and accuracy of 29.2%, 93.5%, 77.8%, 63.0%, and 65.6%, respectively. Ultrasound-guided biopsies in combination with synovial WBC increased the NPV to 76.7% and accuracy to 73.8%. When synovial WBC and calprotectin were combined with ultrasound-guided biopsies, it resulted in a better diagnostic value: sensitivity 69.2%, specificity 80.0%, PPV 69.2%, NPV 80.0%, and accuracy 75.8%. Ultrasound-guided biopsies in combination with calprotectin and ESR yielded a sensitivity of 50.0%, specificity of 93.8%, PPV of 80.0%, NPV of 78.9%, and accuracy of 79.2%. Synovial fluid was obtained in 42 patients. Sensitivities of WBC, PMN, IL-6, and calprotectin were between 25.0% and 35.7%, specificities between 89.5% and 95.0%, PPVs between 60.0% and 83.3%, NPVs between 65.4% and 69.4%, and accuracies between 64.5% and 70.6%. Conclusions. In this prospective study we showed that ultrasound-guided biopsies for cultures alone and in combination with PCR and/or synovial markers are not reliable enough to use in clinical practice for the preoperative diagnosis of low grade PSI


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 8 - 8
1 Feb 2021
Pour AE Patel K Anjaria M Schwarzkopf R Dorr L Lazennec J
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Introduction. Sagittal pelvic tilt (SPT) can change with spinal pathologies and fusion. Change in the SPT can result in impingement and hip instability. Our aim was to determine the magnitude of the SPT change for hip instability to test the hypothesis that the magnitude of SPT change for hip instability is less than 10° and it is not similar for different hip motions. Methods. Hip implant motions were simulated in standing, sitting, sit-to-stand, bending forward, squatting and pivoting in Matlab software. When prosthetic head and liner are parallel, femoral head dome (FHD) faces the center of the liner. FHD moves toward the edge of the liner with hip motions. The maximum distance between the FHD and the center in each motion was calculated and analyzed. To make the results more reliable and to consider the possibility of bony impingement, when the FHD approached 90% of the distance between the liner-center and liner-edge, we considered the hip “in danger for dislocation”. The implant orientations and SPT were modified by 1-degree increments and we used linear regression with receiver operating characteristic (ROC) curve and area under the curve (AUC) to determine the magnitude of SPT change that could cause instability. Results. SPT modification as low as 7° could result in dislocation during pivoting (AUC: 87.5; sensitivity: 87.9; specificity 79.8; p=0.0001). This was as low as 10° for squatting (AUC: 91.5; sensitivity: 100; specificity 75.9; p=0.0001) and as low as 13° for sit-to-stand (AUC: 94.6; sensitivity: 98; specificity 83; p=0.0001). SPT modification affects hip stability more in pivoting than sit-to-stand and squatting. Discussion. Our results show the importance of close collaboration between the hip and spine surgeons in treating patients who undergo THA and spinal fusion. The postoperative SPT modification should be considered for preoperative computer simulation for determining the implant safe zone


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 40 - 40
1 Aug 2020
Li A Glaris Z Goetz TJ
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Physical examination is critical to formation of a differential diagnosis in patients with ulnar-sided wrist pain. Although the specificity and sensitivity of some of those tests have been reported in the literature, the prevalence of positive findings of those provocative maneuvers has not been reported. The aim of the study is to find the prevalence of positive findings of the most commonly performed tests for ulnar sided wrist pain in a population presenting to UE surgeon clinics, and to correlate those findings with wrist arthroscopy findings. Patients with ulnar sided wrist pain were identified from a prospective database of patients presented with wrist pain from September 2014. Prevalence of positive findings for the following tests were gathered: ECU synergy test, ECU instability test (Ice cream and Fly Swatter), Lunotriquetral ballottement, Kleinman shear, triquetrum tenderness, triquetrum compression test, triquetral-hamate tenderness, pisotriquetral shuck test, ulnar fovea test, ulnocarpal impaction (UCI) maneuver, UCI maneuver with fovea pressure (ulnar carpal plus test), piano key sign. A subgroup was then created for those who underwent wrist arthroscopy, and analysis of the sensitivities, the specificities and the predictive values of these provocative tests was carried out with correlation to arthroscopic finding. Prevalence of ECU instability tests was t 1.13% (ice cream scoop) and 1.5% (fly swatter). Lunotriquetral ballottement test's positive findings range from 4.91% (excessive laxity) to 14.34% (pain reproducing symptoms. The Kleinman shear test yielded pain in 13.58% of patients, and instability in only 2.26%. Triquetrum compression test reproduces pain in 32.83% of patients, and triquetral-hamate tenderness reproduced pain in 13.21%. Pisotriquetral grind test yields 15.85% positive findings for pain, and 10.57% for crepitus with radioulnar translation. The ulnar fovea test revealed pain in 69.05% of cases. The UCI maneuver yielded pain in 70.19%. The UCI maneuver plus ulnar fovea test reproduced pain in 80.38% of cases. Finally, the piano key sign yields positive finding in 2.64% of cases. For patients who underwent surgery, sensitivities, specificities and predictive values were calculated based on arthroscopic findings. The lunotriquetral ballottement test has 59.6% sensitivity, 39.6% specificity, 20.3% positive predictive value and 85.4% negative predictive value. The sensitivity of Kleinman test was 62.4%, the specificity was 41.3%, the positive predictive value was 23.5%, and the negative predictive value was 83.2%. The sensitivity of fovea test was 94.3%, the specificity was 82.5%, the positive predictive value was 89.5% and the negative predictive value was 92.3%. The UCI maneuver plus ulnar fovea test has 96.5% sensitivity, 80.7% specificity 86.4% positive predictive value, and 95.3% negative predictive value. Among the provocative tests, the prevalence of positive findings is low in the majority of those maneuvers. The exceptions are the fovea test, the UCI maneuver, and the UCI plus maneuver. With regard to the sensitivity and the specificity of those tests, the current study reproduces the numbers reported in the literature. Of those patients who underwent wrist arthroscopy, the tests are better at predicting at the absence of injury rather than at predicting its presence


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 125 - 125
1 Jul 2020
Chen T Camp M Tchoukanov A Narayanan U Lee J
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Technology within medicine has great potential to bring about more accessible, efficient, and a higher quality delivery of care. Paediatric supracondylar fractures are the most common elbow fracture in children and at our institution often have high rates of unnecessary long term clinical follow-up, leading to an inefficient use of healthcare and patient resources. This study aims to evaluate patient and clinical factors that significantly predict necessity for further clinical visits following closed reduction and percutaneous pinning. A total of 246 children who underwent closed reduction and percutaneous pinning following supracondylar humerus fractures were prospectively enrolled over a two year period. Patient demographics, perioperative course, goniometric measurements, functional outcome measures, clinical assessment and decision making for further follow up were assessed. Categorical and continuous variables were analyzed and screened for significance via bivariate regression. Significant covariates were used to develop a predictive model through multivariate logistical regression. A probability cut-off was determined on the Receiver Operator Characteristic (ROC) curve using the Youden index to maximize sensitivity and specificity. The regression model performance was then prospectively tested against 22 patients in a blind comparison to evaluate accuracy. 246 paediatrics patients were collected, with 29 cases requiring further follow up past the three month visit. Significant predictive factors for follow up were residual nerve palsy (p < 0 .001) and maximum active flexion angle of injured elbow (p < 0 .001). Insignificant factors included other goniometric measures, subjective evaluations, and functional outcomes scores. The probability of requiring further clinical follow up at the 3 month post-op point can be estimated with the equation: logit(follow-up) = 11.319 + 5.518(nerve palsy) − 0.108(maximum active flexion). Goodness of fit of the model was verified with Nagelkerke R2 = 0.574 and Hosmer & Lemeshow chi-square (p = 0.739). Area Under Curve of the ROC curve was C = 0.919 (SE = 0.035, 95% CI 0.850 – 0.988). Using Youden's Index, a cut-off for probability of follow up was set at 0.094 with the overall sensitivity and specificity maximized to 86.2% and 88% respectively. Using this model and cohort, 194 three month clinic visits would have been deemed medically unnecessary. Preliminary blind prospective testing against the 22 patient cohort demonstrates a model sensitivity and specificity at 100% and 75% respectively, correctly deeming 15 visits unnecessary. Virtual clinics and automated clinical decision making can improve healthcare inefficiencies, unclog clinic wait times, and ultimately enhance quality of care delivery. Our regression model is highly accurate in determining medical necessity for physician examination at the three month visit following supracondylar fracture closed reduction and percutaneous pinning. When applied correctly, there is potential for significant reductions in health care expenditures and in the economic burden on patient families by removing unnecessary visits. In light of positive patient and family receptiveness toward technology, our promising findings and predictive model may pave the way for remote health care delivery, virtual clinics, and automated clinical decision making


The ability to calculate quality-adjusted life-years (QALYs) for degenerative cervical myelopathy (DCM) would enhance treatment decision making and facilitate economic analysis. QALYs are calculated using utilities, or health-related quality-of-life (HRQoL) weights. An instrument designed for cervical myelopathy disease would increase the sensitivity and specificity of HRQoL assessments. The objective of this study is to develop a multi-attribute utility function for the modified Japanese Orthopedic Association (mJOA) Score. We recruited a sample of 760 adults from a market research panel. Using an online discrete choice experiment (DCE), participants rated 8 choice sets based on mJOA health states. A multi-attribute utility function was estimated using a mixed multinomial-logit regression model (MIXL). The sample was partitioned into a training set used for model fitting and validation set used for model evaluation. The regression model demonstrated good predictive performance on the validation set with an AUC of 0.81 (95% CI: 0.80-0.82)). The regression model was used to develop a utility scoring rubric for the mJOA. Regression results revealed that participants did not regard all mJOA domains as equally important. The rank order of importance was (in decreasing order): lower extremity motor function, upper extremity motor function, sphincter function, upper extremity sensation. This study provides a simple technique for converting the mJOA score to utilities and quantify the importance of mJOA domains. The ability to evaluate QALYs for DCM will facilitate economic analysis and patient counseling. Clinicians should use these findings in order to offer treatments that maximize function in the attributes viewed most important by patients


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_17 | Pages 65 - 65
24 Nov 2023
Schindler M Walter N Sigmund IK Maderbacher G Alt V Rupp M
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Background. The identification of novel biomarker which is highly specific and sensitive for periprosthetic joint (PJI) have the potential to improve diagnostic accuracy and ultimately improve patient outcomes. Thus, the aim of this systemic review is to identify and evaluate novel biomarkers for the preoperative diagnostics of PJI. Methods. MEDLINE, EMBASE, PubMed and Cochrane Library databases identified from 1. st. of January 2018 to 30. th. of September. 2022. We used “periprosthetic joint infection” OR “prosthetic joint infection” OR “periprosthetic infection” as the diagnosis of interest and the target index applied AND “marker”. To focus on novel biomarkers already used biomarkers of the established PJI diagnostic criteria of MSIS, ICM and EBJIS were not included in the analysis. These three criteria were considered the reference standard during quality assessment. Results. A total of 19 studies were included. In these, fourteen different novel biomarkers were analyzed. Fifteen studies (79%) had prospective designs and the other four (22%) were retrospective studies. Six studies (33%) included only periprosthetic knee infections and thirteen (67%) included periprosthetic knee and hip infections. Proteins were analyzed in most cases (nine studies), followed by molecules (three studies), exosome (two studies) as well as DNA (two studies), interleukin (one study) and lysosome (one study). One novel and promising marker that had been frequently analyzed is calprotectin. Conclusion. No marker demonstrated higher sensitivity and specificity than already known parameters used for standardized treatment based on established PJI definitions. Further studies are needed to elucidate the benefit and usefulness of implementing new biomarkers in diagnostic PJI settings


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_19 | Pages 45 - 45
22 Nov 2024
Stoddart C Hennessy C Ashworth J Vaz J Alvand A Kendrick B Palmer A Partington K
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Aim. Prosthetic joint infection (PJI) is assessed using clinical history and examination, imaging studies and laboratory investigations which inform diagnostic tools such as that proposed by the European Bone and Joint Infection Society to determine the probability of infection. Infection is often confirmed by microbiology culture and histology from intraoperative samples, but ideally a diagnosis of infection is made preoperatively to guide management decisions. At our institution, a tertiary referral centre for PJI, ultrasound (US)-guided synovial biopsy is routinely used as an adjunct to preoperative joint aspiration. Our aim was to evaluate the sensitivity and specificity of microbiology and histology results from US-guided synovial biopsy samples when compared to intraoperative samples. Method. In this retrospective study we analysed all prosthetic hip and knee US-guided biopsies performed at our institution over a 5 year period between 2018 and 2022. Microbiology and histology results from preoperative biopsy samples were individually compared to microbiology and histology findings from intraoperative samples. Results. 381 biopsies were performed; 281 knee, 100 hip. US-guided biopsy results showed strong positive predictive values (PPVs) in hip biopsies (microbiology PPV (79.3%), histology PPV (85.7%)) and knee biopsies (microbiology PPV (77%), histology PPV (85%)). Biopsies showed low sensitivity in predicting intraoperative findings (hip microbiology sensitivity (62%), hip histology sensitivity (31%), knee microbiology sensitivity (70%), knee histology sensitivity (21%). Biopsies showed high specificity for knee (microbiology specificity (89%), histology specificity (97%)) and hip (microbiology specificity (73%), histology specificity (91%)). Conclusions. This study demonstrates that US-guided biopsy is a valuable diagnostic aid for PJI with high specificities and PPVs. Furthermore US-biopsy is valuable when there is limited fluid for aspiration


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_10 | Pages 66 - 66
1 Oct 2022
Hulsen D Arts C Geurts J Loeffen D Mitea C
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Aim. Magnetic resonance imaging (MRI) and 2-[. 18. F]-fluoro-2-deoxy-D-glucose (. 18. F-FDG) Positron Emission Tomography, paired with Computed Tomography (PET/CT) are two indicated advanced imaging modalities in the complicated diagnostic work-up of osteomyelitis. PET/MRI is a relatively novel hybrid modality with suggested applications in musculoskeletal infection imaging. The goal of this study was to assess the value of hybrid . 18. F-FDG PET/MRI for chronic osteomyelitis diagnosis and surgical planning. Method. Five suspected chronic osteomyelitis patients underwent a prospective . 18. F-FDG single-injection/dual-imaging protocol with hybrid PET/CT and hybrid PET/MR. Diagnosis and relevant clinical features for the surgeon planning treatment were compared. Subsequently, 36 patients with . 18. F-FDG PET/MRI scans for suspected osteomyelitis were analysed retrospectively. Sensitivity, specificity, and accuracy were determined with the clinical assessment as the ground truth. Standardized uptake values (SUV) were measured and analysed by means of receiver operating characteristics (ROC). Results. The consensus diagnosis was identical for PET/CT and PET/MRI in the prospective cases, with PET/CT missing one clinical feature. The retrospective analysis yielded a sensitivity, specificity, and accuracy of 78%, 100%, and 86% respectively. Area under the ROC curve was .736, .755, and.769 for the SUVmax, target to background ratio, and SUVmax_ratio respectively. These results are in the same range and not statistically different compared to diagnostic value for . 18. F-FDG PET/CT imaging of osteomyelitis in literature. Conclusions. Based on our qualitative comparison, reduced radiation dose, and the diagnostic value that was found, the authors propose . 18. F-FDG PET/MRI as an alternative to . 18. F-FDG PET/CT in osteomyelitis diagnosis, if available


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_15 | Pages 58 - 58
1 Dec 2021
Ayoglu N Karaismailoglu B Botanlioglu H
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Aim. The diagnosis of septic arthritis mostly relies on clinical examination, several blood parameters including white blood cell count, C-reactive protein, sedimentation, and the analysis of the joint aspiration. However, the diagnosis can be difficult when the symptoms are vague and the information obtained from laboratory might be insufficient for definitive diagnosis. This study aimed to evaluate several ratios obtained from routine blood tests for a possible use in the diagnosis of septic arthritis. Method. The adult patients who were operated in our clinic due to septic arthritis between 2014–2020 were identified and retrospectively evaluated. The patients with any blood disorders or missing file information were excluded. A total of 36 patients were found to be eligible for inclusion. The control group included 40 patients without any sign of infection who underwent total knee arthroplasty due to knee osteoarthritis. Preoperative blood tests of each patients were examined. In addition to CRP and sedimentation values, neutrophil-lymphocyte, monocyte-lymphocyte, platelet-lymphocyte, and platelet count-mean platelet volume were calculated and receiving operating characteristics (ROC) curve analysis was made to determine the sensitivity, specificity and area under curve (AUC) values of these parameters. Results. The distribution of affected joint in septic arthritis group was as follow; 22 knees, 6 hips, 4 shoulders, 2 elbows, 1 wrist and 1 ankle. The cultures of joint aspiration yielded positive result in 19 patients while the cultures were negative in 17 patients. All of the analyzed parameters were significantly different between the groups (p<0.001). ROC curve analysis results are given in detail, in Table 1 and Figure 1. The AUC value was 97.3 when only CRP and sedimentation values were used but increased to 98.6 when neutrophile/ lymphocyte ratio was added and increased to 100 when all analyzed parameters were included. Conclusions. The analyzed parameters were found to increase the overall sensitivity and specificity when used together with acute phase reactants. However, when evaluated separately, CRP and sedimentation were still found as the most valuable parameters in the diagnosis of septic arthritis. In the diagnosis of septic arthritis, 35 mm/hr cut-off value for sedimentation and 10 mg/L cut-off value for CRP were found more sensitive and specific compared to standard laboratory cut-off values of 20 mm/hr and 5 mg/L. For any tables or figures, please contact the authors directly