Analysis of the Causes of Elevated C-Reactive Protein Level in the Early Postoperative Period After Primary Total Knee Arthroplasty

Impact of enhanced recovery after surgery on postoperative blood management following primary total knee arthroplasty: a propensity score-matched analysis

PURPOSE

To evaluate the efficacy of blood management in patients underwent unilateral Total Knee Arthroplasty (TKA) under an enhanced recovery after surgery (ERAS) program.

METHOD

Patients underwent unilateral TKA from January 2019 to October 2023 in a university hospital were retrospectively studied. A total of 200 cases were selected in the analysis. After matching with propensity scoring, 51 patients in each group were included. The postoperative Haemoglobin (Hb), albumin (Alb), C-reactive protein (CRP), total length of stay (LOS), and estimated blood loss after operation were compared between the two groups. Clinical outcomes including Western Ontario and McMaster Universities Arthritis Index (WOMAC), SF-12, and Oxford Knee Score (OKS) were also compared at six week and three month follow-up.

RESULTS

The results showed that the Hb of the ERAS group was significantly higher than those of the non-ERAS group (P < 0.05) on the third postoperative. The mean CRP level was lower, LOS was shorter, and Alb level was higher in the ERAS group compared to that in the non-ERAS group (P < 0.05). The clinical outcomes such as WOMAC and OKS, SF-12 scores were higher in the ERAS group at both follow-up.

CONCLUSION

ERAS protocol effectively minimizes perioperative blood loss and supports optimal nutrient levels in patients. ERAS management significantly contributes to the postoperative recovery of knee function in patients undergoing primary total knee arthroplasty.

Inflammatory Marker Changes Following Total Knee Arthroplasty for Rheumatoid Arthritis with Vancomycin-loaded Calcium Sulfate Bone Filling

Rheumatoid arthritis (RA) patients undergoing total knee arthroplasty (TKA) face infection risk. The study evaluates vancomycin-loaded calcium sulfate bone as infection prevention. Patients with RA treated with TKA who had their femoral canal filled using either vancomycin-loaded calcium sulfate bone (experimental group [n = 35]) or the patient's own excised autologous bone (control group [n = 30]) at the Qingdao University Affiliated Hospital, Qingdao, China from January 1, 2017, to March 1, 2023, were retrospectively enrolled in this study. An experienced surgeon used midvastus approach. Surgeries included disinfection, antibiotics, and femoral filling. The age, gender, body mass index (BMI), comorbidities, and intraoperative details were extracted from the patient's medical records. Preoperation and postoperation markers (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR]), pain scale (Visual Analog Scale [VAS]), infection rate, and Knee Society Score (KSS) were collected. Groups matched in age, gender, and BMI. No preoperative inflammatory marker differences were observed. However, compared to the control group, the postoperative inflammatory markers were significantly lower in the experimental group at 1-week postsurgery (CRP: 40.80 ± 23.17 vs. 60.80 ± 43.12 mg/L, p = 0.021; ESR: 72.06 ± 17.52 vs. 83.87 ± 21.52 mm/h, p = 0.012) and at 1-month postsurgery (CRP: 15.63 ± 6.56 vs. 21.17 ± 13.16 mg/L, p = 0.032; ESR: 25.25 ± 20.44 vs. 38.40 ± 25.26 mm/h, p = 0.024). There were no significant differences in the VAS (2.79 ± 0.90 vs. 2.70 ± 0.84 score, p = 0.689) and KSS (64.31 ± 17.88 vs. 66.57 ± 12.36) at 1-month postsurgery. Experimental group: zero infections; control group: only one infection. Administering vancomycin and calcium sulfate during TKA in RA patients reduces postoperative inflammation, but does not significantly affect infection risk; further research may be necessary for validation.

Dilution of humoral immunity: Results from a natural history study of healthy total knee arthroplasty patients

The incidence of prosthetic joint infection (PJI) following elective primary total knee arthroplasty (TKA) is very low but serious risk remains. To identify unknown risk factors, we completed a natural history study of IgG specific for Staphylococcus aureus antigens previously phenotyped as protective (anti-Atl) and pathogenic (anti-Isd). Twenty-five male and 25 female optimized patients 50-85 years of age and BMI 24-39 undergoing primary TKA were prospectively enrolled. Blood sampling was performed preoperatively, postoperative Day 1, and at 2, 6, and 12 weeks, to assess serum cytokine, anti-staphylococcal IgG levels and anti-tetanus toxoid IgG measured via custom Luminex assay. Clinical, demographic, and PROMIS-10 data were collected with outcomes to 2 years postop. All participants completed the study and 2-year follow-up. No patients were readmitted or noted to develop a surgical site infection or serious adverse event, and patient-reported outcomes were improved. Serology revealed a highly significant decrease in six out of eight antibody titers against specific S. aureus antigens on Day 1 (p < 0.0001), five of which normalized to preoperative levels within 2 weeks. These changes were commensurate with a decrease and recovery of anti-tetanus toxoid titers, and a 20% drop in hemoglobin 13.8 ± 1.7 at preop to 11.1 ± 1.8 mg/dL on Day 1 (p < 0.0001). After TKA, a significant decrease in humoral immunity commensurate with blood loss and hemodilution was recorded. This decrease in circulating anti-staphylococcal antibodies in the early postop period may represent a periprosthetic joint infection risk factor for patients.

Diagnosis and Management of Infected Total Ankle Replacements

As the number of primary total ankle replacements increases for treatment of end-stage ankle arthritis, failures are also expected to rise. Periprosthetic joint infection is among the causes of failures and has been reported to be as high as 5%. Diagnosis is usually made by a combination of clinical examination findings, imaging, laboratory, and microbiological workup. Management is generally separated into limb salvage or amputation. Limb salvage can be challenging and may involve a single versus staged approach. Options include revision arthroplasty or arthrodesis procedures (ankle versus tibiotalocalcaneal), and a multidisciplinary approach is sought to eradicate infection before definitive management.

Relationship Between Pre- and Post-Operative C-Reactive Protein (CRP), Neutrophil-to-Lymphocyte Ratio (NLR), and Platelet-to-Lymphocyte Ratio (PLR) With Post-Operative Pain After Total Hip and Knee Arthroplasty: An Observational Study

BACKGROUND

Anesthetic technique and postoperative pain management are crucial for total joint arthroplasty (TJA) patients. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) are new, simple, and cost-effective predictors for prognosis. The predictive value of NLR as an inflammatory marker can predict post-operative pain caused by inflammatory pathways secondary to surgical trauma. CRP is also the most sensitive and specific biomarker of inflammation whereas PLR was also recently considered a possible marker for inflammation which may further contribute to pain and sequelae. Thus, anesthetists can make decisions about the amount, time, and type of analgesic to use based on preoperative values of these parameters to provide maximum postoperative pain control and facilitate early rehabilitation. Thus, the current study was conducted to determine the relationship between CRP, NLR, and PLR levels and the intensity of pain in patients following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

MATERIALS AND METHODS

A total of 105 patients scheduled for THA and TKA fulfilling the study's inclusion criteria were enrolled. Inclusion criteria of the study were all the patients giving written consent, ASA Grade I-III, patients between 18 and 90 years who were scheduled for elective lower extremity TJA, and all the patients who remained admitted until stitches were removed. Patients were given intrathecal 15 mg hyperbaric bupivacaine via 25G atraumatic spinal needle in the L3-L4 interspace. The recorded data were demographic characteristics, preexisting comorbidities, number of blood transfusions, and operation time, postoperative analgesics given, duration of hospital stay, time of mobility, pain scoring as per visual analog scale (VAS) scoring system with an aim to establish a relationship between pre- and post-operative (Days 3 & 5) CRP, NLR, and PLR with post-operative pain after THA and TKA.

RESULT

The present study demonstrated a significant correlation (p < 0.002) between preoperative and postoperative NLR with pain after TJA whereas PLR and CRP did not show any significant relationship with post-operative pain after THA and TKA. A significantly higher NLR ratio was observed for patients on all the periods of observation (pre-op., Day 3, and Day 5). Pre-op. and Day 5 NLR of patients who required transfusion were significantly higher than those who did not require transfusion and patients with higher NLR values could be mobilized significantly later and had significantly higher duration of hospital stay. The correlation of CRP levels and PLR levels at different time intervals did not show a significant correlation with Day 3 and Day 5 pain scores.

CONCLUSION

The present study demonstrated a significant correlation between preoperative and postoperative NLR with pain after TJA.

Intravascular volume status and stress markers in patients observing long and short duration of fasting: A prospective single blinded observational study

BACKGROUND

Preoperative fasting may lead to intravascular volume depletion and this volume depletion may be a cause of perioperative stress. This study intends to compare the levels of stress markers in patients undergoing long and short duration fasting before an elective laparoscopic surgery.

METHOD

This was a single blind, observational study. Based on the duration of fasting, 70 ASA I and II category patients undergoing elective laparoscopic cholecystectomy(LC) were divided into two groups of 35 patients each. If the surgeon had prescribed a fasting since midnight then patient was considered for inclusion in Long fasting (LF) group; if surgeon had allowed clear fluids till 2 h before surgery then the patient was considered for inclusion in the short fasting(SF) group. The extent of intravascular volume depletion was measured using inferior vena cava collapsibility index (IVCCI). Levels of relevant stress markers i.e. cortisol, Tetraiodothyronine (FT4), C-peptide, C-reactive protein(CRP) and blood glucose (BGL) were measured at 8 PM in the night before surgery, at 7 AM on the day of surgery, 2 h after the surgery and 24 h after the surgery.

RESULT

IVCCI was significantly more in the LF group; 27.66 ± 3.34% vs17.83 ± 2.22%, 95% CI 8.47-11.18, P-value <0.001). IVCCI had a significant correlation with the duration of fasting, Pearson's correlation r = 0.69,P-value <0.001. Repeated measures ANCOVA revealed that CRP, Free T4 and C-peptide levels got significantly elevated over the study duration, P-values <0.001,<0.001 and 0.03 respectively but with IVCCI, Age and Gender as the covariates, the increase in the levels of CRP, Free T4 and C-peptide were similar in both the groups.

CONCLUSION

Stress markers levels show significant elevation in the perioperative period, maximum over the study duration, but this change is similar in both the groups.

CLINICAL TRIAL NO

CTRI/2021/02/031456.

Trend of Perioperative CRP (C-Reactive Protein) Levels in Non-Infected Total Knee Arthroplasty

The aim of this prospective study was to define the perioperative trend of C-reactive protein (CRP) in non-infected total knee arthroplasty (TKA). CRP was evaluated in 42 patients the day before surgery and 4 and 30 days after surgery. Functional and radiological evaluation was scheduled for 3, 6, and 12 months after surgery. Preoperatively, the median CRP was 3.2 mg/L (IQR,3.2-4.2) (reference range, 0-5 mg/L); 4 and 30 days after surgery, it measured 57.6 mg/L (IQR,36.1-96.4) and 5.3 mg/L (IQR,3.0-11.8), respectively. There were significant differences between the CRP preoperatively and 4 days after surgery (p<0.001) and between CPR levels 4 and 30 days after surgery (p<0.001) but not between CRP values preoperatively and 30 days after surgery (p=0.181). Higher preoperative CRP was associated to heart disease and chronic renal failure (r=0.329, p=0.036, and r=0.437, p=0.004, respectively). Four days after surgery, higher CRP was associated to older patients (r=0.311, p=0.048). In summary, 30 days after primary non-infected TKA, CRP levels were comparable to preoperative values. Older age and comorbidities should be carefully evaluated using postoperative CRP as diagnostic marker for the early detection of infection.

The effects of pre-emptive intravenous ibuprofen on the thiol/disulfide homeostasis and C-reactive protein level as the markers of oxidative stress and inflammation during gynecologic laparoscopy: A randomised clinical trial

AIMS

In this study, we aimed to investigate the anti-inflammatory and antioxidant effects of intravenous ibuprofen by using the C-reactive protein level and thiol/disulfide homeostasis as the oxidative stress marker.

MATERIALS AND METHODS

This study was conducted on 70 patients aged between 30 and 65 who were scheduled for elective laparoscopic hysterectomy. The patients were divided into two groups to receive either pre-emptive 800mg of intravenous ibuprofen plus 1000 mg of intravenous paracetamol (Group IP) or only 1000 mg of intravenous paracetamol as a control group (Group P). The blood samples for thiol/disulfide homeostasis were collected as follows: before induction of anesthesia (T0), before pneumoperitoneum (T1), following postdeflation and discontinuation of anesthesia (T2), and postoperative 24th hour (T3). Simultaneous blood samples for C-reactive protein (CRP) were also collected. The pre- and postoperative urea, creatinine, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels were measured.

RESULTS

A total of 69 patients were included in the study. The patient's characteristics and intraoperative variables were comparable between groups (P > .05). The number of patients requiring rescue analgesia, the total amount of analgesic used, Visual Analog Scale (VAS) scores, and postoperative side effects were significantly lower in Group IP (P < .001). The decrease in native and total thiol levels at T1, T2, and T3 measurement points was significant in Group IP (P < .001). In both groups, the comparison to baseline values demonstrated no significant changes in terms of disulfide level (P > .05). The simultaneous CRP levels indicated a significant increase at the postoperative 24 hour in both groups (P < .001). The difference between groups was insignificant (P > .05). There was a significant increase in urea and creatinine levels in patients of Group IP (P < .05).

CONCLUSION

The pre-emptive administration of ibuprofen provided effective pain control after gynecologic laparoscopy. However, ibuprofen changed the thiol/disulfide homeostasis in favor of oxidation and had no beneficial effect in surgically induced oxidative stress.

Serum Inflammatory Biomarkers in the Diagnosis of Periprosthetic Joint Infections

Accurate preoperative diagnosis of periprosthetic joint infections (PJIs) can be very challenging, especially in patients with chronic PJI caused by low-virulence microorganisms. Serum parameters, such as serum C-reactive protein (CRP) or the erythrocyte sedimentation rate (ESR), are—among other diagnostic test methods—widely used to distinguish septic from aseptic failure after total hip or knee arthroplasty and are recommended by the AAOS in the preoperative setting. However, they are systemic parameters, and therefore, unspecific. Nevertheless, they may be the first and occasionally the only preoperative indication, especially when clinical symptoms are lacking. They are easy to obtain, cheap, and are available worldwide. In the last decade, different novel serum biomarkers (percentage of neutrophils, neutrophils to lymphocytes ratio, platelet count to mean platelet volume ratio, fibrinogen, D-Dimer, Il-6, PCT) were investigated to find a more specific and accurate serum parameter in the diagnosis of PJI. This article reviews the diagnostic value of established (serum CRP, ESR, WBC) and ‘novel’ serum inflammatory biomarkers (fibrinogen, D-dimer, interleukin-6 (IL-6), procalcitonin, percentage of neutrophils (%N), neutrophils to lymphocytes ratio (NLR), platelet count to mean platelet volume ratio (PC/mPV)) for the preoperative diagnosis of periprosthetic joint infections.

Low-Load Unilateral and Bilateral Resistance Training to Restore Lower Limb Function in the Early Rehabilitation After Total Knee Arthroplasty: A Randomized Active-Controlled Clinical Trial

Background: Continuous passive motion (CPM) is frequently used during rehabilitation following total knee arthroplasty (TKA). Low-load resistance training (LLRT) using continuous active motion (CAM) devices is a promising alternative. We investigated the effectiveness of CPM compared to LLRT using the affected leg (CAMuni) and both legs (CAMbi) in the early post-operative rehabilitation. Hypotheses: (I) LLRT (CAMuni and CAMbi) is superior to CPM, (II) additional training of the unaffected leg (CAMbi) is more effective than unilateral training (CAMuni).

Materials and Methods: Eighty-five TKA patients were randomly assigned to three groups, respectively: (i) unilateral CPM of the operated leg; (ii) unilateral CAM of the operated leg (CAMuni); (iii) bilateral alternating CAM (CAMbi). Patients were assessed 1 day before TKA (pre-test), 1 day before discharge (post-test), and 3 months post-operatively (follow-up). Primary outcome: active knee flexion range of motion (ROM_Flex). Secondary outcomes: active knee extension ROM (ROM_Ext), swelling, pain, C-reactive protein, quality of life (Qol), physical activity, timed-up-and-go performance, stair-climbing performance, quadriceps muscle strength. Analyses of covariances were performed (modified intention-to-treat and per-protocol).

Results: Hypothesis I: Primary outcome: CAMbi resulted in a higher ROM_Flex of 9.0° (95%CI −18.03–0.04°, d = 0.76) and 6.3° (95%CI −14.31–0.99°, d = 0.61) compared to CPM at post-test and follow-up, respectively. Secondary outcomes: At post-test, C-reactive protein was lower in both CAM groups compared with CPM. Knee pain was lower in CAMuni compared to CPM. Improved ROM_Ext, reduced swelling, better stair-climbing and timed-up-and-go performance were observed for CAMbi compared to CPM. At follow-up, both CAM groups reported higher Qol and CAMbi showed a better timed-up-and-go performance. Hypothesis II: Primary outcome: CAMbi resulted in a higher knee ROM_Flex of 6.5° (95%CI −2.16–15.21°, d = 0.56) compared to CAMuni at post-test. Secondary outcomes: At post-test, improved ROM_Ext, reduced swelling, and better timed-up-and-go performance were observed in CAMbi compared to CAMuni.

Conclusions: Additional LLRT of the unaffected leg (CAMbi) seems to be more effective for recovery of function than training of the affected leg only (CAMuni), which may be mediated by positive transfer effects from the unaffected to the affected limb (cross education) and/or preserved neuromuscular function of the trained, unaffected leg.

Trial Registration:ClinicalTrials.gov Identifier: NCT02062138.

Circulating D-Dimer versus Fibrinogen in the Diagnosis of Peri-Prosthetic Joint Infection: A Meta-Analysis

Background: Circulating D-dimer and fibrinogen are both emerging as promising biomarkers for the diagnosis of peri-prosthetic joint infection (PJI), but their clinical values still remain disputable. This study aims to evaluate and compare the accuracy of circulating D-dimer and fibrinogen in the diagnosis of suspected PJI. Methods: We conducted a comprehensive literature search in PubMed, EMBASE, and the Cochrane Library to retrieve diagnostic accuracy studies in which PJI was investigated with circulating D-dimer or fibrinogen from the time of database inception to August 1, 2019. The pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratio (DOR), summary receiver operating characteristic (sROC) curves, and area under the sROC curve (AUC) were constructed using a meta-analysis framework. Results: Seven eligible studies (1,374 patients) were included in the quantitative analysis. The mean levels of circulating D-dimer and fibrinogen were all significantly higher in patients with PJI. The plasma fibrinogen illustrated relatively higher sensitivity (0.84, 95% confidence interval [CI]: 0.78-0.98) and specificity (0.80, 95% CI: 0.76-0.84) than circulating D-dimer (0.74, 95% CI: 0.69-0.78; 0.66, 95% CI: 0.62-0.69, respectively) for the diagnosis of PJI. The pooled DOR of D-dimer, fibrinogen, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) to diagnose PJI was 7.00 (95% CI, 2.50-19.59), 12.40 (95% CI, 5.85 to 26.28), 10.71 (95% CI, 7.76 to 14.78) and 16.22 (95% CI 11.71-22.46), respectively, while the pooled AUC was 0.84 (95% CI, 0.77-0.90), 0.87 (95% CI, 0.85-0.89), 0.82 (95% CI, 0.78-0.85) and 0.87 (95% CI, 0.86-0.88), respectively. Conclusions: This meta-analysis reveals that it could be concluded that plasma fibrinogen is an excellent biomarker for diagnosing PJI, comparable to serum CRP and ESR, while the diagnostic value of circulating D-dimer is only moderate. Large-scale, prospective studies are still needed to confirm current findings.

Are Cement Spacers and Beads Loaded with the Correct Antibiotic(s) at the Site of Periprosthetic Hip and Knee Joint Infections?

The optimal impregnation of antibiotic-loaded bone cement in the treatment of periprosthetic hip and knee joint infection is unknown. It is also unclear, whether a suboptimal impregnation might be associated with a higher persistence of infection. A total of 93 patients (44 knee, 49 hip) were retrospectively evaluated, and the most common organism was a methicillin-resistant Staphylococcus epidermidis, followed by methicillin-susceptible Staphylococcus aureus. Of all the organisms, 37.1% were resistant against gentamicin and 54.2% against clindamycin. All organisms were susceptible against vancomycin. In 41 cases, gentamicin-loaded beads were inserted and in 52 cases, spacers: (2 loaded only with gentamicin, 18 with gentamicin + vancomycin, 19 with gentamicin + clindamycin, and 13 with gentamicin + vancomycin + clindamycin). The analysis of each antibiotic impregnation showed that complete susceptibility was present in 38.7% of the cases and partial susceptibility in 28%. In the remaining 33.3%, no precise statement can be made because either there was a culture-negative infection or the antibiotic(s) were not tested against the specific organism. At a mean follow-up of 27.9 months, treatment failure was observed in 6.7% of the cases. Independent of which antibiotic impregnation was used, when the organism was susceptible against the locally inserted antibiotics or not tested, reinfection or persistence of infection was observed in the great majority of cases. Future studies about the investigation of the optimal impregnation of antibiotic-loaded bone cement are welcome.

Prevention of Periprosthetic Joint Infection (PJI): A Clinical Practice Protocol in High-Risk Patients

Background: Periprosthetic joint infection (PJI) represents 25% of failed total knee arthroplasties (TKA). The European Knee Associates (EKA) formed a transatlantic panel of experts to perform a literature review examining patient-related risk factors with the objective of producing perioperative recommendations in PJI high-risk patients. Methods: Multiple databases (Pubmed/MEDLINE, EMBASE, Scopus, Cochrane Library) and recommendations on TKA PJI prevention measures from the International Consensus Meetings on PJI from the AAOS and AAHKS were reviewed. This represents a Level IV study. Results: Strong evidence was found on poor glycemic control, obesity, malnutrition, and smoking being all associated with increased rates of PJI. In the preoperative period, patient optimization is key: BMI < 35, diet optimization, Hemoglobin A1c < 7.5, Fructosamine < 292 mmol/L, smoking cessation, and MRSA nasal screening all showed strong evidence on reducing PJI risk. Intraoperatively, a weight-based antibiotic prophylaxis, accurate fluid resuscitation, betadine and chlorhexidine dual skin preparation, diluted povidone iodine solution irrigation, tranexamic acid administration, and monofilament barbed triclosan-coated sutures for soft tissues closure all represented effective prevention measures. In the postoperative period, failure to reach normalization of ESR, CRP, D-dimer, and IL-6 six weeks postoperatively suggested early PJI. Conclusion: The current recommendations from this group of experts, based on published evidence, support risk stratification to identify high-risk patients requiring implementation of perioperative measures to reduce postoperative PJI.

Predictive values of the postoperative neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio for the diagnosis of early periprosthetic joint infections: a preliminary study

Background

Several studies have been conducted to report diagnostic values of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in the many diseases, such as oncological, inflammatory, and some infectious diseases. However, the predictive value of these laboratory parameters for early periprosthetic joint infections (PJIs) has not yet been reported. The aim of this study was to determine predictive values of the postoperative NLR, PLR, and LMR for the diagnosis of PJIs.

Methods

In this retrospective study, 104 patients (26 early PJI cases and 78 non-PJI cases) who underwent total joint arthroplasty were enrolled in this study. All the patients were then categorized into two groups: PJI group, patients with the diagnosis of PJI (26 patients; 14 males, 12 females; mean age = 65.47 ± 10.23 age range = 51–81 ) and non-PJI group, patients without PJI (78 patients; 40 males, 38 females; mean age = 62.15 ± 9.33, age range = 41–92). We defined “suspected time” as the time that any abnormal symptoms or signs occurred, including fever, local swelling, or redness around the surgical site between 2 and 4 weeks after surgery and before the diagnosis. Suspected time and laboratory parameters, including NLR, PLR, LMR, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), were compared between both groups. The trends of postoperative NLR, LMR, PLR, CRP, and ESR were also reviewed. The predictive ability of these parameters at the suspected time for early PJI was evaluated by multivariate analysis and receiver operating characteristic (ROC) curve analysis.

Results

NLR, PLR, and LMR returned to preoperative levels within 2 weeks after surgery in the two groups. In the PJI group, NLR and PLR were significantly increased during the incubation period of infection or infection, and LMR was significantly reduced, although 61.5% (16/26) of the patients had normal white blood cells. Interestingly, ESR and CRP were still relatively high 2 weeks after surgery and were not different between the two groups before infection started (p = 0.12 and 0.4, respectively). NLR and PLR were significantly correlated with early PJI (Odds ratios for NLR and PLR = 88.36 and 1.12, respectively; p values for NLR and PLR = 0.005 and 0.01, respectively). NLR had great predictive ability for the diagnosis of early PJI, with a cut-off value of 2.77 (sensitivity = 84.6%, specificity = 89.7%, 95% CI = 0.86–0.97).

Conclusions

ESR and CRP seem not to be sensitive for the diagnosis of early PJI due to their persistently high levels after arthroplasty. The postoperative NLR at the suspected time may have a great ability to predict early PJI.

Preventive Epidural Analgesia in Bilateral Single-Stage Knee Arthroplasty: A Randomized Controlled Trial

INTRODUCTION

Although controversial, pre-emptive analgesia has shown some promise in preventing altered pain perception and reducing pain amplification after surgery. Hence, it has the potential to be more effective than a similar analgesic regimen started after surgery with an appropriate combination of patient category and analgesic modality. Hence, the present study was undertaken to evaluate the effect of preventive epidural analgesia in reducing pain severity and duration after bilateral single-stage knee arthroplasty.

METHODS

Fifty patients, 18-70 years, with American Society of Anesthesiologists physical status class I & II posted for bilateral single-stage knee replacement under regional anesthesia were randomly allocated into preventive versus postoperative epidural analgesia group to compare severity of post-operative pain, analgesic consumption, day of mobilization, C-reactive protein (CRP) levels, and hospital stay.

RESULTS

The pain score after surgery [2.0 (1.5, 2.0); 3.0 (1.5, 3.0), p = 0.005] and day of mobilization [(2. 92 ± 0. 28; 3. 31 ± 0. 48; p value 0.02)] were significantly lesser in the preventive epidural group. However, there was no difference in the hospital stay (9.92 ± 3.71 and 9.00 ± 2.12, p = 0.95) and analgesic consumption (65.38 ± 37.55 and 73.08 ± 43.85, p = 0.30). The preventive group had a larger drop in CRP and experienced a lesser number of days with pain after surgery as compared to the controls [(64.29 ± 21.29); (142.37 ± 80.04), p = 0.0001]. Six patients in the preemptive group (24%) and 13 of the control group (24 vs. 56.5%; p = 0.02) had chronic postsurgical pain.

CONCLUSIONS

Preventive epidural analgesia reduces the severity and number of chronic pain days after bilateral single-stage knee replacement.

TRIAL REGISTRATION

The study was registered in the Indian national registry (CTRI/2017/03/008240 on 28/03/2017).

Positive Microbiological Findings at the Site of Presumed Aseptic Revision Arthroplasty Surgery of the Hip and Knee Joint: Is a Surgical Revision Always Necessary?

Little is known about patients that undergo presumed aseptic revision arthroplasty surgery of the hip and knee joint and having positive microbiological findings of the intraoperatively taken tissue samples. 228 “aseptic” operations were retrospectively analyzed from prospectively collected data with regard to the following parameters: demographic data; reasons for primary and revision surgery, respectively; time between primary and revision surgery; preoperative laboratory findings; microbiological and histopathological findings; type and length of systemic antibiotic therapy; clinical outcome; and follow-up. Identification of microorganisms was present in 8.8% of the cases (9.3% of the hip and 7.8% of the knee cases). Preoperatively, the median CRP value was 8.4 mg/l (normal values 0-5.0 mg/l) and the median WBC count 8,100 × 10⁶/l (normal values 3, 700‐10,100 × 10⁶/l). The most common identified organism was methicillin-resistant Staphylococcus epidermidis in 30%, followed by viridans streptococci in 15% of the cases. In 7 cases, the microbiological findings were interpreted as a contamination, and no antibiotic therapy was administered. In the other cases, a systemic antibiotic therapy was applied for a time period between 2 weeks and 3 months. 68.4% of the patients did not have any infectious complications at a median follow-up of 20 (3-42) months. The present study indicates that more than 2/3 of the cases with positive microbiological findings at the site of presumed aseptic revision arthroplasty surgery of the hip and knee joint can be successfully treated conservatively and they do not require any further surgical therapy.

Comparison of D-dimer with CRP and ESR for diagnosis of periprosthetic joint infection

Background

Despite the availability of several biomarkers, the diagnosis of periprosthetic joint infection (PJI) continues to be challenging. Serum D-dimer assessment is a widely available test that detects fibrinolytic activities and has been reported as an inflammatory biomarker. However, quite a few articles have reported the diagnostic efficiency of D-dimer for PJI.

Methods

This prospective study enrolled patients who had undergone total joint arthroplasty, were suspected of PJI, and also prepared for revision arthroplasty. PJI was defined using the Musculoskeletal Infection Society criteria. In all patients, serum D-dimer level, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) level were measured preoperatively. We then compared the diagnostic efficiency of these three biomarkers.

Results

The median D-dimer level was significantly higher (p < 0.001) for the patients with PJI than for the patients with aseptic failure. With a sensitivity of 80.77% (95% CI, 65.62 to 95.92%) and a specificity of 79.63% (95% CI, 68.89 to 90.37%), the diagnostic efficiency of D-dimer did not outperform serum CRP (with a sensitivity of 84.61% and specificity of 64.81%) and ESR (with a sensitivity of 73.08% and specificity of 90.47%).

Conclusions

Serum D-dimer as a marker for the diagnosis of PJI still requires more large-scale and detailed clinical trials.

Usefulness of serum D‑dimer for preoperative diagnosis of infected nonunion after open reduction and internal fixation

Purpose

Infected nonunion after open reduction internal fixation (ORIF) is a serious complication. The aim of this study was to evaluate the usefulness of serum D-dimer for preoperative diagnosis of infected nonunion.

Patients and methods

Patients undergoing debridement and external fixation for infected nonunion (n=32) and replacement of internal fixation due to aseptic failure (n=34) were enrolled and compared in this retrospective study. The optimum cutoff value of D-dimer for identification of infected nonunion was determined by calculating the Youden J statistic. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of four preoperative laboratory parameters—serum D-dimer level, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)—for diagnosis of infected nonunion were compared.

Results

Serum D-dimer level was significantly higher in patients with infected nonunion than in patients with aseptic nonunion: 2.62 mg/mL (range, 0.13–11.90 mg/mL) vs 0.35 mg/mL (range, 0.07–6.46 mg/mL; p<0.001). WBC count, CRP, and ESR demonstrated sensitivity of 12.5% (95% CI: 4.08–29.93), 40.6% (95% CI: 24.22–59.21), and 56.3% (95% CI: 37.88–73.16), respectively, and specificity of 94.1% (95% CI: 78.94–98.97), 88.2% (95% CI: 71.61–96.16), and 85.3% (95% CI: 68.17–94.46), respectively. Using the Youden index, 1.70 mg/mL was determined as the optimal threshold value for serum D-dimer for the diagnosis of infected nonunion. The sensitivity and specificity of serum D-dimer (>1.70 mg/mL) were 75.0% (95% CI: 56.25–87.87) and 91.2% (95% CI: 75.19–97.69).

Conclusions

Serum D-dimer level may be useful for preoperative prediction of infected nonunion in patients after ORIF.

Suitability of serum cytokine profiling for early diagnosis of implant-associated infections after orthopaedic surgery: A preliminary prospective study

The C-reactive protein (CRP) is still the conventional marker used to diagnose implant-associated infections (IAI) after orthopaedic surgery. However, the CRP level can lead to misdiagnosis since it is up-regulated not only during bacterial infection. In this prospective study, we evaluated the serum cytokine profile before (pre-OP) and after orthopaedic surgery (post-OP) as well as after confirmation of a developed infection (COI) to identify candidate biomarkers for diagnosis of IAI. Sera from 10 controls 7 to 1 days pre-OP and 0 to 22 days post-OP as well as from 5 patients who developed IAI 5 to 1 days pre-OP, 0 to 197 days post-OP and after COI were analyzed for 27 different cytokines using a multiplex cytokine assay. In addition to CRP, 14 cytokines IL-1ra, IL-4, IL-5, IL-6, IL-8, IL-12(p70), IL-13, IL-17, eotaxin, G-CSF, IFN-γ, IP-10, MCP-1, and MIP-1β were significantly altered (P ≤ 0.05) during the study although some differences were low-fold elevations compared to the pre-OP levels. IL-6 as well as IL-12(p70) were consistently elevated in infected patients. Surgery influenced cytokine production with some overlap of cytokines in both groups, implying that the use of cytokines is maximized when the cytokines are not or no longer affected by surgical trauma. To lend more robustness to the selection of candidate cytokines, in addition to the statistical differences, we applied a threshold cut-off of approximately 2-fold elevations when comparisons were made. This resulted in the selection of 8 cytokines, namely IL-6, IL-1ra, IL-8, IL-12(p70), eotaxin, IP-10, MCP-1, and MIP-1β, which may be used in a multiplex assay for detection of IAI after surgery. Furthermore, IL-1ra and IL-8 may be used as prognostic cytokines prior to surgery. The present results imply that the use of cytokines may be a suitable alternative to CRP for IAI diagnosis.

Natural progress of D-dimer following total joint arthroplasty: a baseline for the diagnosis of the early postoperative infection

Background

Early detection followed by prompt intervention is essential for the treatment of periprosthetic joint infection (PJI). D-dimer, a fibrin degradation product, characteristically changes rapidly during early postoperative period and has a short half-life. The aim of this prospective study was to measure postoperative change of D-dimer level after joint arthroplasty in conjunction with ESR and CRP.

Methods

ESR, CRP, and D-dimer levels were measured on the day before surgery, postoperative days 1, 2, 3, and 5 and weeks 2 and 6 in 65 patients who underwent elective primary total hip arthroplasty (38 hips in 38 patients) or total knee arthroplasty (27 knees in 27 patients). We compared perioperative changes of the three biomarkers.

Results

ESR level was elevated from postoperative day 1 and reached a peak level of 45 mm/h at postoperative day 5. The elevation persisted until postoperative week 6. CRP level was elevated from postoperative day 1 and reached a peak level of 10 mg/dl between postoperative day 2 and day 3. The CRP level was decreased to the normal level around postoperative week 2. D-dimer level was sharply elevated and peaked to 4.5 μg/dl at postoperative day 1. At postoperative day 2, it decreased to baseline level. After then, it slowly elevated again and reached a second peak at postoperative week 2.

Conclusion

D-dimer showed a more rapid rise and fall than ESR and CRP in very early postoperative period. The D-dimer test might be effective in early detection of PJI, if combined with levels of ESR and CRP. The postoperative change of D-dimer in our study can serve as a baseline for early diagnosis of PJI.

Serum biomarkers in periprosthetic joint infections

OBJECTIVES

The diagnosis of periprosthetic joint infection (PJI) is difficult and requires a battery of tests and clinical findings. The purpose of this review is to summarize all current evidence for common and new serum biomarkers utilized in the diagnosis of PJI.

METHODS

We searched two literature databases, using terms that encompass all hip and knee arthroplasty procedures, as well as PJI and statistical terms reflecting diagnostic parameters. The findings are summarized as a narrative review.

RESULTS

Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were the two most commonly published serum biomarkers. Most evidence did not identify other serum biomarkers that are clearly superior to ESR and CRP. Other serum biomarkers have not demonstrated superior sensitivity and have failed to replace CRP and ESR as first-line screening tests. D-dimer appears to be a promising biomarker, but more research is necessary. Factors that influence serum biomarkers include temporal trends, stage of revision, and implant-related factors (metallosis).

CONCLUSION

Our review helped to identify factors that can influence serum biomarkers' level changes; the recognition of such factors can help improve their diagnostic utility. As such, we cannot rely on ESR and CRP alone for the diagnosis of PJI prior to second-stage reimplantation, or in metal-on-metal or corrosion cases. The future of serum biomarkers will likely shift towards using genomics and proteomics to identify proteins transcribed via messenger RNA in response to infection and sepsis.Cite this article:Bone Joint Res 2018;7:85-93.

How To Diagnose and Treat Infection in Total Ankle Arthroplasty

Periprosthetic infection after total ankle arthroplasty (TAA) is a serious complication, often requiring revision surgery, including revision arthroplasty, conversion to ankle arthrodesis, or even amputation. Risk factors for periprosthetic ankle infection include prior surgery at the site of infection, low functional preoperative score, diabetes, and wound healing problems. The clinical presentation of patients with periprosthetic ankle joint infection can be variable and dependent on infection manifestation: acute versus chronic. The initial evaluation in patients with suspected periprosthetic joint infections should include blood tests: C-reactive protein and erythrocyte sedimentation rate. Joint aspiration and synovial fluid analysis can help confirm suspected periprosthetic ankle infection.