Can the Leukocyte Esterase Strip Test Predict Persistence of Periprosthetic Joint Infection at Second-Stage Reimplantation?

BACKGROUND: We evaluated the reliability of intraoperative assessment of leukocyte esterase (LE) in synovial fluid samples from patients undergoing reimplantation following implant removal and spacer insertion for periprosthetic joint infection (PJI). Our hypothesis was that a positive intraoperative LE test would be a better predictor of persistent infection than either serum C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) or the combination of serum CRP and ESR. METHODS: The records of 76 patients who received a 2-stage exchange for PJI were retrospectively reviewed. Synovial fluid was collected for LE measurement during surgery before arthrotomy in 79 procedures. Receiver operating characteristic curves were generated. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve (AUC) of LE, CRP, ESR, and CRP + ESR were calculated. RESULTS: Sensitivity, specificity, positive predictive value, and negative predictive value of the LE assay were 82%, 99%, 90%, and 97%, respectively. Receiver operating characteristic analysis revealed an LE threshold of 1.5 between the first (negative) and the second (positive) level of the ordinal variable, so that a grade starting from 1+ was accurate for a diagnosis of persistent infection (AUC 0.9044). The best thresholds for the CRP and the ESR assay were 8.25 mg/L (82% sensitivity, 84% specificity, AUC 0.8416) and 45 mm/h (55% sensitivity, 87% specificity, AUC 0.7493), respectively. CONCLUSION: The LE strip test proved a reliable tool to diagnose persistence of infection and outperformed the serum CRP and ESR assays. The strip test provides a valuable intraoperative diagnostic during second-stage revision for PJI.

The role of suction drainage in the management of peri-operative bleeding in Total and Unicomcompartmental knee arthroplasty: a retrospective comparative study.

BACKGROUND: Suction drainage is commonly applied after total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) to reduce hematoma, swelling and to favor surgical wound healing. However, its efficacy remains controversial; thus, the purpose of this study is to evaluate drainage efficiency in the management of postoperative bleeding in TKA and UKA. METHODS: The cohort comprised 134 clinical records of patients affected by knee osteoarthritis (OA) who underwent either TKA or UKA. All the patients were subdivided into 2 groups: the first one with drainage and the second one without drainage (respectively 61 and 73 patients). For each group, hemoglobin levels in the preoperative, first, second and third postoperative day were collected. Postoperative complications such as swelling, bleeding from the surgical wound or the need for blood transfusion, were also recorded. RESULTS: Our results did not show any significant difference of hemoglobin levels in the first (p = 0.715), second (p = 0.203) and third post-operative day (p = 0.467) between the two groups. Moreover, no significant correlation between knee swelling or transfusion rate and the drainage was observed (p = 0.703 and p = 0.662 respectively). Besides, a significant correlation was found between bleeding from the surgical wound and the absence of drainage (p = 0.006). CONCLUSIONS: The study demonstrates how the routine use of suction drainage does not provide substantial benefits in the postoperative blood loss management after TKA or UKA. TRIAL REGISTRATION: ClinicalTrials.gov NCT04508101 , 09/08/2020, Retrospectively registered LEVEL OF EVIDENCE: III.

Is the newest fibrin sealant an effective strategy to reduce blood loss after total knee arthroplasty? A randomized controlled study.

An RCT was conducted to ascertain whether, compared to control management, topical application of a novel fibrin sealant (Evicel, J&J) in patients undergoing primary TKA reduces peri-operative blood loss. Sixty-two patients were randomized to receive topical application of Evicel (N = 31) or not (N = 31). The mean total blood loss was 1.9L(± 0.7) in the control group and 1.8L(± 0.5) in the treatment group (P = 0.4). The transfusion rate was 32.3% in the control group and 25.8% in the treatment group (P = 0.5). The transfusion rate decreased linearly with increasing preoperative Hb levels in the treatment group (P = 0.005). The results of this study suggest that topical application of this novel fibrin sealant doesn't reduce perioperative blood loss and the need for allogeneic blood transfusion.

Value of digital telethermography for the diagnosis of septic knee prosthesis: a prospective cohort study.

BACKGROUND: Diagnosis of peri-prosthetic infection remains challenging, often requiring a combination of different tests. METHODS: In this prospective, case-control study, the diagnostic accuracy of telethermography was evaluated in a group of seventy patients who had had a total knee replacement and were undergoing a reoperation because of infection or another implant-related problem, after a minimum of one year from implant. RESULTS: An average differential temperature of the affected versus not affected knee of 1.9 °C was observed in infected prosthesis, compared to 0.3 °C in aseptic failures. Considering a normal reference value equal or less than 1.0 °C, telethermography showed an accuracy, sensitivity, specificity, positive and negative predictive value of, respectively: 0.90, 0.89, 0.91, 0.91, 0.88. CONCLUSIONS: Digital telethermography is a reliable option for diagnosing peri-prosthetic knee infection.

Knee Pathology before and after SARS-CoV-2 Pandemic: An Analysis of 1139 Patients.

BACKGROUND: The SARS-CoV-2 pandemic drastically changed daily life activities and medical practice, leading to a reorganization of healthcare activities. People spent two months in home-isolation, changing their daily habits and undertaking a more sedentary lifestyle. Change in lifestyle is related to important consequences in knee pathologies. The aim of this study was to evaluate the outpatient activity for knee pathologies before and after lockdown in terms of incidence, severity, diagnosis, and treatment. METHODS: Medical records of patients with knee pathology in outpatient follow-up at IRCCS Istituto Ortopedico Galeazzi in Milan (Italy) were analyzed in the time frame 4 May-4 September 2020 and compared with patients examined between 4 May and 4 September 2019. RESULTS: A significant increase of knee diagnoses associated to patellofemoral disorders in 2020 was found (p = 0.004). In addition, physiotherapy was significantly more prescribed in 2020 than in 2019 (p = 0.012). CONCLUSIONS: The SARS-CoV-2 pandemic lockdown did not drastically change knee pathology, but it may have had an impact on it, highlighting a summary worsening of patellofemoral disorders associated with other knee diagnoses. Further studies are required to validate this result.

Remote Management of Patients after Total Joint Arthroplasty via a Web-Based Registry during the COVID-19 Pandemic.

BACKGROUND: In 2020, due to the outbreak of the COVID-19 (Coronavirus Disease 2019) pandemic, patients who underwent total joint arthroplasty were not able to undergo the proper postoperative surgical and rehabilitative care. This study aims to evaluate the potential of a web-cloud-based database on patients' follow-up in extraordinary situations, when a traditional in-person follow-up cannot be warranted. METHODS: Patients who underwent joint arthroplasty at our Institute between 21 February and 16 March 2020 were included in the study group and were matched to a similar population undergoing joint arthroplasty in February/March 2019. All patients routinely complete questionnaires before and after treatment, including patient-reported outcome measures such as the Visual Analogues Scale (VAS), Knee/Hip Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS/HOOS-PS) and Short-Form Health Survey (SF-12) for the monitoring of clinical improvements. RESULTS: 56 (study group) and 144 (control group) patients were included in the study. Both groups demonstrated significant improvements at 3 months. HOOS-PS improvement was significantly reduced in the 2020 group compared to 2019 (21.7 vs. 33.9, p < 0.001). This reduction was related to intense physical activities. Similarly, the functional score improvement related to these activities was reduced for patients undergoing knee replacement (8 vs. 10, p < 0.05). CONCLUSIONS: The web-based Institute Registry emerged as a meaningful and sensitive tool during an extraordinary situation such as the COVID-19 pandemic to monitor patients' progression after total joint arthroplasties. Thanks to this tool, it was possible to observe that the prevention of usual postoperative care due to pandemic-related restrictions did not alter the benefits observed after joint replacement surgeries, even if this condition reduced the postoperative improvements in the most burdensome physical activities. A broader use of this kind of tool would improve and potentially reduce the burden and costs of postoperative patients' monitoring in standard and extraordinary conditions. In addition, the systematic remote collection of data would allow for the identification of relevant differences in clinical outcomes in specific conditions or following the modification of treatment and rehabilitation protocols.

Posterior cruciate ligament-retaining and posterior-stabilized total knee arthroplasty: differences in surgical technique.

The debate over the relative merits of substituting or retaining the posterior cruciate ligament in total knee arthroplasty is still ongoing. This article discusses the differences between the two procedures, considering the biomechanics and the surgical techniques involved.

Comparative chondrogenesis of human cells in a 3D integrated experimental-computational mechanobiology model.

We present an integrated experimental-computational mechanobiology model of chondrogenesis. The response of human articular chondrocytes to culture medium perfusion, versus perfusion associated with cyclic pressurisation, versus non-perfused culture, was compared in a pellet culture model, and multiphysic computation was used to quantify oxygen transport and flow dynamics in the various culture conditions. At 2 weeks of culture, the measured cell metabolic activity and the matrix content in collagen type II and aggrecan were greatest in the perfused+pressurised pellets. The main effects of perfusion alone, relative to static controls, were to suppress collagen type I and GAG contents, which were greatest in the non-perfused pellets. All pellets showed a peripheral layer of proliferating cells, which was thickest in the perfused pellets, and most pellets showed internal gradients in cell density and matrix composition. In perfused pellets, the computed lowest oxygen concentration was 0.075 mM (7.5% tension), the maximal oxygen flux was 477.5 nmol/m(2)/s and the maximal fluid shear stress, acting on the pellet surface, was 1.8 mPa (0.018 dyn/cm(2)). In the non-perfused pellets, the lowest oxygen concentration was 0.003 mM (0.3% tension) and the maximal oxygen flux was 102.4 nmol/m(2)/s. A local correlation was observed, between the gradients in pellet properties obtained from histology, and the oxygen fields calculated with multiphysic simulation. Our results show up-regulation of hyaline matrix protein production by human chondrocytes in response to perfusion associated with cyclic pressurisation. These results could be favourably exploited in tissue engineering applications.

Comfrey extract ointment in comparison to diclofenac gel in the treatment of acute unilateral ankle sprains (distortions).

OBJECTIVES: A previously published study comparing the efficacy of comfrey extract to a commercial diclofenac (CAS 78213-16-8) preparation in the treatment of unilateral ankle sprains is critically re-evaluated. The study was designed to show non-inferiority of the comfrey extract. The data were re-evaluated for superiority according to CPMP guidelines. The study was an observer-blind, randomised, multi-centre clinical trial with two independent treatment groups "comfrey extract" and "diclofenac gel" (parallel group design) and included a total of 164 patients (82 in the comfrey group and 82 in the diclofenac group, intention-to-treat (ITT) analysis). Key variables were the area under the curve (AUC) from Visits 1 to 2 of the difference of the tenderness values contra-lateral minus injured side (primary variable), pain assessment (Visual Analogue Scale, VAS) at rest and on movement by patient, swelling (figure-of-eight method) and ankle movement (neutral zero method). On average (mean difference comfrey extract minus diclofenac), the AUC was +61.1 h x N/cm2 greater for patients treated with comfrey extract compared to diclofenac treated patients (95% confidence interval: 19.08; 103.09 h x N/cm2). The difference between the two treatment groups was statistically significant (analysis of variance with factors "study drug", "centre", and "drug x centre interaction"). Safety was excellent in both treatment groups. The re-evaluation of the data showed superiority of the plant based ointment over the diclofenac gel in the treatment of distortions. It is encouraging and impressive to realize that a natural product seems to be an effective and safe alternative to the standard topical treatment with diclofenac.